CN100504363C - Inspection apparatus, inspection method, inspection apparatus, inspection method of wiring pattern - Google Patents

Abstract

A wiring pattern inspection apparatus includes a light source (10), a parallel light guide member that guides light from the light source to be substantially parallel, and a light extraction member that extracts a transverse wave light component from the light guided by the parallel light guide member, the transverse wave light component intersecting perpendicularly to a light guide direction, and that converts the transverse wave light component into a specific polarization component and irradiates a workpiece (51) with the specific polarization component, and extracts a perpendicular wave light component from reflected light obtained by reflecting the emitted specific polarization component by the workpiece.

Description

Wiring pattern inspection equipment, inspection method, inspection equipment, inspection method

technical field

The present invention relates to an inspection device, inspection method, inspection device and inspection method of a wiring pattern for optically extracting a wiring pattern of an uppermost layer in a multilayer wiring substrate of a semiconductor package and picking up an image by high resolution, thereby automatically The pattern is inspected and detected efficiently, in which a plurality of wiring patterns are stacked via an insulating layer of polyimide having transparency, for example, on a multilayer wiring substrate of the semiconductor package.

Background technique

Generally, in a wiring pattern formed on a multilayer wiring substrate for semiconductor packaging to make electronic equipment smaller or lighter, copper foil is laminated on a polyimide film via an adhesive and passed through a subtractive process , semi-additive process, etc., and the thickness of a part is 5-15 μm, and the highest integration has a width of about 10 μm.

In this patterning process step, there is a fear that serious defects such as thinning (cracks) of wiring patterns, disconnection of wirings, short circuits, and thickening (protrusions) may suddenly occur. Therefore, the presence of these defects has hitherto been judged by open/short inspection or visual inspection. However, visual inspection has a problem in that it requires skill for pattern minimization, and fluctuations or defect omissions occur in inspection results due to physical conditions of inspectors and the like. Then, in recent years, various types of automatic inspection apparatuses have been proposed which automatically inspect the presence of defects using cameras (for example, Jpn. Pat. Appln. KOKAI Publication No. 10-19531 (Example 1) and Jpn. Pat. .No. 2962565 (Fig. 5, 7)). Also, it is possible to visually inspect various types of defects existing in a wiring pattern having a minimum width of 10 μm in a multilayer wiring substrate of a semiconductor package, but there is a problem that a large amount of inspection time is required for visual inspection, and as individual costs increase Increase product unit price increase. Therefore, automatic checking is required. For example, to detect 1/3 or more defects within a width of 10 μm, an imaging resolution of 1 μm must be achieved. To solve this problem, it is necessary to find imaging methods, inspection methods, further processing methods, etc. from a broad viewpoint of the relationship between imaging resolution and imaging field of view (object processing size).

In general, in automatic inspection equipment that automatically inspects the presence of defects using cameras, multiple wiring patterns on the same workpiece are simultaneously imaged using time differences in divided areas, etc., by multiple sensor cameras (line CCD devices, area CCD devices, etc.) , and recognize the image. Through this process, defects such as thinning (cracks), disconnection of wiring, short circuits, thickening (protrusions), etc. existing in the wiring pattern are detected. As a recognition process, a general method is to register in advance CAD data (pattern design information) or a satisfactory workpiece (a workpiece on which a wiring pattern is correctly formed) as a reference master image, and use such as this master image and an inspection image (inspection object Pattern image) comparison process and feature extraction process will judge the part with difference as a defect. Simultaneously, the image is checked reflectively, the wiring pattern formed on the uppermost layer is recorded, and the image is picked up in most cases without considering any influence of the inner layer wiring pattern.

As an example of the reason for this, the inner layer wiring pattern does not exist in the product, or even the imaging of the uppermost layer wiring pattern in the product in which the inner layer wiring pattern exists is not affected by the insulating layer substrate placed between the wiring patterns. Influence of type, substrate thickness, substrate color, transmission/reflection spectral sensitivity, etc. Even when the inner wiring pattern is present and plays a slight role, this effect can be easily eliminated by threshold adjustment when imaging, and the reflection effect of the inner wiring pattern does not have to be regarded as an optical problem from the beginning.

However, in the case of using conventional inspection equipment, in a multilayer wiring substrate for semiconductor packaging, when the polyimide film insulating layer interposed between wiring patterns and having transparency has a thickness of about 10 to 25 μm and It is small, and when an attempt is made to image the uppermost layer wiring pattern with high resolution, the wiring pattern existing in the inner layer is reflected, and a clear pattern image in which only the uppermost layer wiring pattern is recorded cannot be obtained.

Also, optical conditions are very important for performing the above inspection using images picked up by a camera. Reliable inspection is not possible even with very sophisticated process algorithms unless defects can be visually visualized.

Furthermore, it has also been proposed to use fluorescent illumination on the wiring pattern and the insulating layer portion to detect the fluorescent component generated by the insulating layer, thereby extracting and detecting the wiring pattern portion in a pseudo manner. However, in this method, an image in which an edge of a wiring pattern is extracted in a pseudo manner is obtained by fluorescence emission. Therefore, defects such as pinholes in the wiring pattern and cracks existing on the top side of the wiring pattern cannot be detected. In order to ensure the quality of a multilayer wiring substrate of a semiconductor package, it is necessary to record and inspect wiring patterns. Therefore, it is required to perform more firmly apparent quality assurance as package inspection in such a way that copper wiring patterns can be directly seen, defects such as micro pinholes and dents can be observed or used to make interlayer connections The filling quality of the through hole and the realization of high-speed signal transmission. Also, when the inspection recording wiring pattern is performed, the manufacturing process is inspected by monitoring good/bad spots of the wiring pattern formed during manufacturing, and control of the process state may be included in order to keep the manufacturing process itself optimal.

Also, the invention described in Jpn. Pat. Appln. KOKAI Publication No. 10-19531 is an invention in which the wiring pattern is imaged as a dark image to thereby image the wiring pattern. Therefore, in the method described in Jpn.Pat.Appln.KOKAI Publication No. 10-19531, the wiring pattern can only be picked up as a dark image, and it is impossible to achieve fine imaging such that micro pinholes and dents can also be observed Defects such as or the degree of quality of filled vias for interlayer connections.

Furthermore, in the invention described in Jpn. Pat. No. 2962565, laser light having a specific wavelength (450 nm or less) is irradiated, and the reflectance of the wiring pattern and the reflectance of the polyimide-based insulating film (ONAL) are utilized The difference between the wiring pattern is picked up as a bright image. However, commonly used CCDs do not have any sensitivity to light with a wavelength of 450nm or below, and require a special imaging system. On the other hand, there is little difference between the reflectance of the wiring pattern and the reflectance of the polyimide-based insulating film (ON AL) for a wavelength to which a conventional CCD is sensitive (for example, about 550 nm). In the method disclosed in Jpn. Pat. No. 2962565, it is difficult to image only the wiring pattern of the uppermost layer without imaging the wiring pattern of the inner layer.

Also, in automatic inspection of wiring patterns, it is necessary to image a wiring pattern having a large area in a short time. However, the method disclosed in Jpn. Pat. No. 2962565 is so-called spot scanning. In this method, laser light is condensed to irradiate a wiring pattern, and the laser light used to irradiate the wiring pattern scans, thereby imaging the wiring pattern. Therefore, it takes a lot of time. Further, in the method disclosed in Jpn. Pat. No. 2962565, the intensity of laser light reflected in various directions on the wiring pattern is detected, and information such as an arrangement angle of the wiring pattern is obtained based on the detected value. Therefore, at least two detection systems must be provided, and the configuration is complicated. In addition, since the values detected by each system are calculated in order to restore the wiring pattern state, the amount of calculation is large.

Contents of the invention

The present invention has been developed in view of the above-mentioned circumstances, and a first object of the present invention is to provide an inspection apparatus, inspection method, inspection apparatus, and inspection method of a wiring pattern in which the multilayer wiring substrate with respect to a semiconductor package is optically eliminated The influence of the wiring pattern of the inner layer is eliminated, thereby picking up a high-precision image of the wiring pattern of the uppermost layer, and the wiring pattern can be checked automatically with great reliability.

Moreover, a second object of the present invention is to provide an inspection apparatus, inspection method, inspection apparatus, and inspection method of a wiring pattern capable of inspecting and inspecting in a short time even for an uppermost layer wiring pattern having a large area and having a simple constitution. Detect the uppermost wiring pattern.

In order to achieve the above object, in the present invention, the following means are adopted.

That is, according to a first aspect of the present invention, there is provided a wiring pattern detection apparatus that optically detects a wiring pattern of an uppermost layer of a workpiece including a semiconductor having a wiring pattern on at least the front/rear surface of a light-transmitting base film. A packaged multilayer wiring substrate, the device comprising: a light source; parallel light guiding means for guiding light from the light source to be substantially parallel; first extracting means for extracting a second light from the light guided by the parallel light guiding means A linearly polarized light whose electric field vector direction is perpendicular to the light guiding direction; a circularly polarized light conversion device is used to convert the first linearly polarized light extracted by the first extracting device into circularly polarized light; an illuminating device is used to utilize the circularly polarized light The circularly polarized light converted by the polarized light conversion device irradiates the workpiece; the second extraction device is used to extract the second linearly polarized light from the reflected light obtained by reflecting the circularly polarized light emitted by the irradiation device by the workpiece, and its electric field vector direction is the same as that of the first a linearly polarized light crossing perpendicularly; and an image pickup device for imaging the second linearly polarized light extracted by the second extracting device.

Therefore, when the above means is adopted in the wiring pattern inspection apparatus of the first aspect of the present invention, the light from the light source is converted into circularly polarized light, and the workpiece can be irradiated with this circularly polarized light. In addition, the second linearly polarized light can be extracted from the reflected light reflected by the irradiated workpiece so as to pick up an image. The second linearly polarized light includes information on the wiring pattern of the uppermost layer.

According to a second aspect of the present invention, there is provided a wiring pattern inspection apparatus capable of optically inspecting an uppermost layer wiring pattern of a workpiece including a semiconductor package having a wiring pattern on at least a front/rear surface of a light-transmitting base film A multilayer wiring substrate, the device comprising: a light source; parallel light guiding means for guiding light from the light source to be substantially parallel; a polarizing beam splitter for extracting a first linear light from the light guided by the parallel light guiding means polarized light whose electric field vector direction is perpendicular to the light guiding direction, and the polarizing beam splitter is also used to direct the extracted first linearly polarized light in a direction perpendicular to the light guiding direction and the electric field vector direction of the first linearly polarized light light; a quarter-wavelength plate for converting the first linearly polarized light guided by the polarizing beam splitter into circularly polarized light; an irradiation device for irradiating a workpiece with the circularly polarized light converted by the quarter-wavelength plate; and an image pickup device.

Moreover, the circularly polarized light emitted by the illuminating device is reversed by the workpiece, thereby reversing the direction of rotation, and then transmitted through the quarter-wave plate, and the second linearly polarized light is extracted by the polarizing beam splitter, whose electric field vector direction is the same as The first linearly polarized light crosses perpendicularly, and the extracted second linearly polarized light is imaged by an image pickup device.

Therefore, when the above means is adopted in the wiring pattern inspection apparatus of the second aspect of the present invention, the quarter-wave plate converts the light from the light source into circularly polarized light, and the workpiece can be irradiated with this circularly polarized light. In addition, the second linearly polarized light can be extracted from the reflected light reflected by the irradiated workpiece through a quarter-wave plate and a polarizing beam splitter, so as to pick up an image. The second linearly polarized light includes information on the wiring pattern of the uppermost layer.

According to a third aspect of the present invention, there is provided a wiring pattern inspection apparatus capable of optically inspecting an uppermost layer wiring pattern of a workpiece including a semiconductor package having a wiring pattern on at least a front/rear surface of a light-transmitting base film A multilayer wiring substrate, the device comprising: a light source; parallel light guiding means for guiding the light from the light source to be substantially parallel; a first polarizing beam splitter for extracting a first polarizing beam splitter from the light guided by the parallel light guiding means A linearly polarized light whose electric field vector direction is perpendicular to the light guiding direction; a second polarizing beam splitter which guides the first polarized light beam in a direction perpendicular to the light guiding direction and the electric field vector direction of the first linearly polarized light The first linearly polarized light extracted by the beam splitter; the quarter-wavelength plate is used to convert the first linearly polarized light guided by the second polarizing beam splitter into circularly polarized light; Circularly polarized light converted by the wavelength plate irradiates the workpiece; and an image pickup device.

Also, the circularly polarized light emitted by the illuminating device is reflected by the workpiece, thereby inverting the direction of rotation, and then transmitted through the quarter-wavelength plate to extract the second linearly polarized light through the second polarizing beam splitter whose electric field vector direction is the same as The first linearly polarized light crosses perpendicularly, and the extracted second linearly polarized light is imaged by an image pickup device.

Therefore, when the above-mentioned means is adopted in the wiring pattern detection apparatus of the third aspect of the present invention, once the light from the light source is converted into the first linearly polarized light, the quarter-wave plate converts the first linearly polarized light into circularly polarized light. polarized light, and the workpiece can be irradiated with this circularly polarized light. In addition, the second linearly polarized light can be extracted from the reflected light reflected by the irradiated workpiece, thereby picking up an image. The second linearly polarized light includes information on the wiring pattern of the uppermost layer.

According to a fourth aspect of the present invention, there is provided a wiring pattern inspection apparatus capable of optically inspecting an uppermost layer wiring pattern of a workpiece including a semiconductor package having a wiring pattern on at least the front/rear surface of a light-transmitting base film A multilayer wiring substrate, the device comprising: a light source; parallel light guiding means for guiding light from the light source to be substantially parallel; a polarizing plate for extracting first linearly polarized light from the light guided by the parallel light guiding means , whose electric field vector direction is perpendicular to the light guiding direction; a polarizing beam splitter, which guides the first linearly polarized light extracted by the polarizing plate in a direction perpendicular to the light guiding direction and the electric field vector direction of the first linearly polarized light; A quarter-wavelength plate for converting the first linearly polarized light guided by the polarizing beam splitter into circularly polarized light; an irradiation device for irradiating a workpiece with the circularly polarized light converted by the quarter-wavelength plate; and an image pickup device .

Also, the circularly polarized light emitted by the illuminating device is reflected by the workpiece, thereby inverting the direction of rotation, and then transmitted through a quarter-wavelength plate to extract a second linearly polarized light through a polarizing beam splitter whose electric field vector direction is the same as that of the first The linearly polarized light crosses perpendicularly, and the extracted second linearly polarized light is imaged by an image pickup device.

Therefore, when the above-mentioned device is adopted in the wiring pattern detection apparatus of the fourth aspect of the present invention, the light from the light source is converted into circularly polarized light by the polarizing plate, the polarizing beam splitter, and the quarter-wavelength plate, and can be used This circularly polarized light illuminates the workpiece. In addition, the second linearly polarized light can be extracted from the reflected light reflected by the irradiated workpiece, thereby picking up an image. The second linearly polarized light includes information on the wiring pattern of the uppermost layer.

According to a fifth aspect of the present invention, there is provided a wiring pattern inspection apparatus capable of optically inspecting an uppermost layer wiring pattern of a workpiece including a semiconductor package having a wiring pattern on at least the front/rear surface of a light-transmitting base film A multilayer wiring substrate, the device comprising: a light source; parallel light guiding means for guiding light from the light source to be substantially parallel; first extracting means for extracting a first linearity from the light guided by the parallel light guiding means Polarized light, whose electric field vector direction is perpendicular to the light guiding direction; the polarized component extracting device is used to obtain a predetermined polarized component from the first linearly polarized light extracted by the first extracting device through a polarizing plate with a predetermined angle; the illuminating device uses The workpiece is irradiated with the polarized component obtained by the polarized component extracting device; the second extracting device is used to extract the second linearly polarized light from the reflected light obtained by reflecting the polarized component emitted by the illuminating device by the workpiece; its electric field vector direction and The first linearly polarized light intersects vertically; the image pickup device is used to image the second linearly polarized light extracted by the second extracting device.

Therefore, when the above means is adopted in the wiring pattern inspection apparatus of the fifth aspect of the present invention, the light from the light source is converted into a polarized component, and the workpiece is irradiated with the polarized component. In addition, the second linearly polarized light can be extracted from the reflected light reflected by the irradiated workpiece, thereby picking up an image. The second linearly polarized light includes information on the wiring pattern of the uppermost layer.

According to a sixth aspect of the present invention, there is provided a wiring pattern inspection apparatus capable of optically inspecting an uppermost layer wiring pattern of a workpiece including a semiconductor package having a wiring pattern on at least the front/rear surface of a light-transmitting base film A multilayer wiring substrate, the device comprising: a light source; parallel light guiding means for guiding light from the light source to be substantially parallel; a polarizing beam splitter for extracting a first linear beam from the light guided by the parallel light guiding means polarized light whose electric field vector direction is perpendicular to the light guiding direction, and the polarizing beam splitter is also used to direct the extracted first linearly polarized light in a direction perpendicular to the light guiding direction and the electric field vector direction of the first linearly polarized light light; polarized component extracting means for obtaining a predetermined polarized component from the first linearly polarized light guided by the polarizing beam splitter through a polarizing plate having a predetermined angle; illuminating means for using the polarized component obtained by the polarized component extracting means irradiating the workpiece; and an image pickup device.

Furthermore, the second linearly polarized light is extracted from the reflected light obtained by reflecting the polarized component emitted by the irradiation device by the polarizing beam splitter, the electric field vector direction of which is perpendicular to the first linearly polarized light, and is detected by the image pickup device. Extract the second linearly polarized light for imaging.

Therefore, when the above-mentioned means is adopted in the wiring pattern inspection apparatus of the sixth aspect of the present invention, the light from the light source is converted into a polarized component, and the workpiece can be irradiated with the polarized component. In addition, the second linearly polarized light can be extracted from the reflected light reflected by the irradiated workpiece to pick up an image. The second linearly polarized light includes information on the wiring pattern of the uppermost layer.

According to a seventh aspect of the present invention, there is provided a wiring pattern inspection apparatus capable of optically inspecting an uppermost layer wiring pattern of a workpiece including a semiconductor package having a wiring pattern on at least the front/rear surface of a light-transmitting base film A multilayer wiring substrate, the device comprising: a light source; parallel light guiding means for guiding the light from the light source to be substantially parallel; a first polarizing beam splitter for extracting a first polarizing beam splitter from the light guided by the parallel light guiding means A linearly polarized light whose electric field vector direction is perpendicular to the light guiding direction; a second polarizing beam splitter which guides the first polarized light beam in a direction perpendicular to the light guiding direction and the electric field vector direction of the first linearly polarized light The first linearly polarized light extracted by the beam splitter; the polarized component extracting device is used to obtain a predetermined polarized component from the first linearly polarized light guided by the second polarized beam splitter through a polarizing plate having a predetermined angle; the illuminating device is used for irradiating the workpiece with the polarization component obtained by the polarization component extraction means; and an image pickup means.

Furthermore, second linearly polarized light is extracted from reflected light obtained by reflecting the polarized component emitted by the irradiation device by the second polarizing beam splitter, whose electric field vector direction perpendicularly intersects the first linearly polarized light, and is picked up by the image The device images the extracted second linearly polarized light.

Therefore, when the above-mentioned means is adopted in the wiring pattern detecting apparatus of the seventh aspect of the present invention, once the light from the light source is converted into the first linearly polarized light, the first linearly polarized light is converted into a polarized component, and can be used This polarized component illuminates the workpiece. In addition, the second linearly polarized light can be extracted from the reflected light reflected by the irradiated workpiece, thereby picking up an image. The second linearly polarized light includes information on the wiring pattern of the uppermost layer.

According to an eighth aspect of the present invention, there is provided a wiring pattern inspection apparatus capable of optically inspecting an uppermost layer wiring pattern of a workpiece including a semiconductor package having a wiring pattern on at least a front/rear surface of a light-transmitting base film A multilayer wiring substrate, the device comprising: a light source; parallel light guiding means for guiding light from the light source to be substantially parallel; a polarizing plate for extracting first linearly polarized light from the light guided by the parallel light guiding means , whose electric field vector direction is perpendicular to the light guiding direction; a polarizing beam splitter for guiding the first linearly polarized light extracted by the polarizing plate in a direction perpendicular to the light guiding direction and the electric field vector direction of the first linearly polarized light Polarized component extracting means, for obtaining predetermined polarized components from the first linearly polarized light guided by the polarizing beam splitter through a polarizing plate having a predetermined angle; Irradiating means, for irradiating with the polarized component obtained by the polarized component extracting means a workpiece; and an image pickup device.

Also, second linearly polarized light perpendicularly intersecting the first linearly polarized light is extracted from reflected light obtained by reflecting a polarized component emitted by the irradiation means by the workpiece, and the extracted second linearly polarized light is processed by the image pickup means imaging.

Therefore, when the above means is adopted in the wiring pattern inspection apparatus of the eighth aspect of the present invention, the light from the light source is converted into a polarized component, and the workpiece can be irradiated with the polarized component. In addition, the second linearly polarized light can be extracted from the reflected light reflected by the irradiated workpiece, thereby picking up an image. The second linearly polarized light includes information on the wiring pattern of the uppermost layer.

According to a ninth aspect of the present invention, in the wiring pattern detection apparatus according to any one of the first to eighth aspects, the image pickup device includes a line sensor that continuously images a predetermined linear region in the workpiece and continuously images The linear regions of are connected to each other, thereby imaging a planar region of the workpiece.

Therefore, when the above-mentioned means is adopted in the wiring pattern inspection apparatus of the ninth aspect of the present invention, the workpiece can be line-scanned, thereby picking up an image, and thus the image can be picked up in a short time compared with point-scanning the workpiece.

According to a tenth aspect of the present invention, in the wiring pattern detection apparatus according to any one of the first to ninth aspects, the parallel light guiding means includes: a light guide for guiding light from a light source; diffusing the light while keeping the intensity distribution constant; parallelizing means for making the light diffused by the diffusing plate substantially parallel; and means for directing the parallel light generated by the parallelizing means.

Therefore, when the above-mentioned means is adopted in the wiring pattern inspection apparatus of the tenth aspect of the present invention, the light from the light source can be diffused while keeping the intensity distribution constant, and high-resolution pickup can be utilized without any non-uniformity at all. image.

According to an eleventh aspect of the present invention, in the wiring pattern detection device in the tenth aspect, a device for removing an infrared component from light from the light source is provided between the light source and the light guide or between the light guide and the diffusion plate. Infrared filter.

Therefore, when the above means is adopted in the wiring pattern detecting device of the eleventh aspect of the present invention, the infrared rays constituting the heat source can be interrupted in such a manner that the infrared rays are prevented from entering the parallel light guiding means, and thus the temperature of the parallel light guiding means can be inhibited. raised.

According to a twelfth aspect of the present invention, the wiring pattern detection apparatus according to any one of the first to eleventh aspects further includes cooling means for cooling the parallel light guiding means.

Therefore, when the above means is employed in the wiring pattern inspection apparatus of the twelfth aspect of the present invention, the parallel light guiding means can be cooled.

According to a thirteenth aspect of the present invention, the wiring pattern detection apparatus according to any one of the first to twelfth aspects further includes: selection means for selecting a wavelength region in which the reflection of the uppermost layer wiring pattern The difference between the amount of light and the amount of reflected light of patterns other than the uppermost layer wiring pattern is greater than a predetermined value in the second linearly polarized light; and selected wavelength light component guiding means for guiding the light component in the wavelength region selected by the selecting means .

Therefore, in the wiring pattern detection apparatus of the thirteenth aspect of the present invention, the above-mentioned means is adopted, and accordingly, in the second linearly polarized light, a wavelength region is selected in which the reflected light amount of the uppermost layer wiring pattern is different from that of the uppermost layer wiring pattern. The difference between the amounts of reflected light of patterns other than the predetermined value is greater than a predetermined value, and an image composed of light components in the selected wavelength region can be picked up. Thus, an image visualized as an uppermost layer wiring pattern can be obtained.

According to a fourteenth aspect of the present invention, in the wiring pattern detection apparatus of the thirteenth aspect, the selected wavelength light component guiding means includes one or two or more lenses, and these lenses are guided in parallel with the image pickup means by the selection means Light components in the selected wavelength region.

Therefore, when the above means is adopted in the wiring pattern detection apparatus of the fourteenth aspect of the present invention, one or two or more lenses are suitably used to guide the light components of the selected wavelength region in parallel with the image pickup means. As a result, a fine image visualized as an uppermost layer wiring pattern can be picked up.

According to a fifteenth aspect of the present invention, in the wiring pattern detection device according to the thirteenth or fourteenth aspect of the present invention, the base film is formed of polyimide resin, the wiring pattern is formed of copper, and the selection means selects a 550nm wavelength region, the image pickup device includes a CCD.

Therefore, in the wiring pattern inspection apparatus of the fifteenth aspect of the present invention, the above-described means are adopted, and accordingly the wiring pattern of the uppermost layer involving Both imide resin and copper are typical materials for base film and wiring pattern.

According to a sixteenth aspect of the present invention, in the wiring pattern inspection apparatus of any one of the first to fourteenth aspects, the workpiece is irradiated with elliptically polarized light instead of circularly polarized light.

Therefore, when the above arrangement is adopted in the wiring pattern inspecting apparatus of the sixteenth aspect of the present invention, the workpiece can be irradiated with not only circularly polarized light but also elliptically polarized light.

According to a seventeenth aspect of the present invention, in the wiring pattern detection device of any one of the first to sixteenth aspects, the light source includes a white light source.

Therefore, when the above arrangement is adopted in the wiring pattern inspection apparatus of the seventeenth aspect of the present invention, a white light source can be used as a light source without using any special light source.

According to an eighteenth aspect of the present invention, there is provided a wiring pattern inspection device, including: inspection means for picking up by the image pickup device of the wiring pattern inspection device according to any one of the first to seventeenth aspects of the present invention The image is compared with a predetermined satisfactory image, thereby checking whether the uppermost layer wiring pattern is satisfactory.

Therefore, when the above-mentioned means is employed in the wiring pattern inspection apparatus of the eighteenth aspect of the present invention, it is possible to inspect with good accuracy whether the wiring pattern of the uppermost layer is satisfactory.

According to a nineteenth aspect of the present invention, there is provided a wiring pattern inspection method capable of optically inspecting an uppermost layer wiring pattern of a workpiece including a semiconductor package having a wiring pattern on at least the front/rear surface of a light-transmitting base film A multilayer wiring substrate, the method comprising: a parallel light guiding step of guiding light substantially in parallel; a first extraction step of extracting first linearly polarized light from light guided by the parallel light guiding step, the first linearly polarized The direction of the electric field vector of the light intersects the light guiding direction perpendicularly; a circularly polarized light converting step of converting the first linearly polarized light extracted by the first extracting step into circularly polarized light; irradiating the workpiece with the circularly polarized light converted by the circularly polarized light converting step an irradiation step; a second extraction step of extracting a second linearly polarized light whose electric field vector direction is the same as that of the first linearly polarized light from reflected light obtained by reflecting the circularly polarized light emitted by the irradiation step by the workpiece perpendicular intersection; and an image pickup step of imaging the second linearly polarized light extracted by the second extraction step.

When the above device is employed in the wiring pattern inspection method of the nineteenth aspect of the present invention, the light from the light source is converted into circularly polarized light, and the workpiece is irradiated with this circularly polarized light. In addition, second linearly polarized light is extracted from the reflected light reflected by the illuminated workpiece and imaged. The second linearly polarized light includes information on the wiring pattern of the uppermost layer.

According to a twentieth aspect of the present invention, there is provided a wiring pattern inspection method capable of optically inspecting an uppermost layer wiring pattern of a workpiece including a semiconductor package having a wiring pattern on at least the front/rear surface of a light-transmitting base film A multilayer wiring substrate, the method comprising: a parallel light guiding means for guiding the light to be substantially parallel; a step of extracting a first linearly polarized light from the light guided by the parallel light guiding means through a polarizing plate, the first The direction of the electric field vector of the linearly polarized light is perpendicular to the light guiding direction; the step of guiding the first linearly polarized light in a direction perpendicular to the light guiding direction and the direction of the electric field vector of the first linearly polarized light using a polarizing beam splitter; utilizing A step of converting the first linearly polarized light guided by the polarizing beam splitter into circularly polarized light by the quarter-wavelength plate; a step of irradiating the workpiece with the circularly polarized light converted by the quarter-wavelength plate; and being reflected and emitted by the workpiece to The circularly polarized light of the workpiece is reversed in the direction of rotation, and then the polarized light is transmitted through a quarter-wavelength plate, and the second linearly polarized light perpendicular to the first linearly polarized light is extracted through a polarizing beam splitter so that the extracted second Steps for imaging with linearly polarized light.

Therefore, when the above-mentioned device is adopted in the wiring pattern detection method of the twentieth aspect of the present invention, the light from the light source is converted into circularly polarized light by the polarizing plate, the polarizing beam splitter, and the quarter-wavelength plate, and can The workpiece is irradiated with this circularly polarized light. In addition, the second linearly polarized light can be extracted from the reflected light reflected by the irradiated workpiece, and imaged. The second linearly polarized light includes information on the wiring pattern of the uppermost layer.

According to a twenty-first aspect of the present invention, there is provided a wiring pattern inspection method capable of optically inspecting an uppermost layer wiring pattern of a workpiece including a semiconductor having a wiring pattern on at least the front/rear surface of a light-transmitting base film A packaged multilayer wiring substrate, the method comprising: a parallel light guiding step for guiding light substantially parallel; a first extracting step of extracting first linearly polarized light from light guided by the parallel light guiding step, the first The electric field vector direction of a linearly polarized light is vertically intersected with the light guiding direction; the polarized component extracting step of obtaining a predetermined polarized component from the first linearly polarized light extracted by the first extracting step through a polarizing plate having a predetermined angle; an irradiating step of irradiating the workpiece with the polarized component obtained in the component extracting step; a second extracting step of extracting second linearly polarized light whose electric field a vector direction perpendicular to the first linearly polarized light; and an image pickup step of imaging the second linearly polarized light extracted by the second extracting step.

Therefore, when the above-described device is employed in the wiring pattern inspection method of the twenty-first aspect of the present invention, the light from the light source is converted into a polarized component, and the workpiece can be irradiated with the polarized component. . In addition, the second linearly polarized light can be extracted from the reflected light reflected by the irradiated workpiece, and imaged. The second linearly polarized light includes information on the wiring pattern of the uppermost layer.

According to the twenty-second aspect of the present invention, in any one of the wiring pattern detection method of the nineteenth to twenty-first aspects, the predetermined linear region in the workpiece is continuously imaged using a line sensor, and the continuously imaged The linear areas are connected to each other, whereby planar areas of the workpiece are imaged.

Therefore, when the above-mentioned device is adopted in the wiring pattern inspection method of the twenty-second aspect of the present invention, the workpiece can be line-scanned, thereby picking up an image, and thus an image can be picked up in a short time compared with point-scanning the workpiece.

According to a twenty-third aspect of the present invention, in the wiring pattern detection method of any one of the nineteenth to twenty-second aspects, the parallel light guiding step includes: a diffusing step of diffusing the light while keeping the intensity distribution constant ; the step of parallelizing substantially parallel the light diffused by the diffusing step; and the step of directing the parallel light produced by the parallelizing step.

Therefore, when the above-mentioned means is adopted in the wiring pattern detecting method of the twenty-third aspect of the present invention, the light from the light source can be diffused while keeping the intensity distribution constant, and it is possible to achieve high resolution to pick up images.

According to the twenty-fourth aspect of the present invention, in the wiring pattern detection method of the twenty-third aspect of the present invention, the parallel light guiding step further includes an infrared ray removing step of removing infrared components from the light before the diffusing step.

Therefore, when the above-mentioned means is adopted in the wiring pattern detection apparatus of the twenty-fourth aspect of the present invention, the infrared rays constituting the heat source can be interrupted in such a manner that the infrared rays are prevented from entering the parallel light-guiding means, and thus the temperature of the light-guiding member can be inhibited. raised.

According to the twenty-fifth aspect of the present invention, the wiring pattern detection method of any one of the nineteenth to twenty-fourth aspects further includes: a selection step of selecting a wavelength region in which the reflection of the uppermost layer wiring pattern a difference between the amount of light and the amount of reflected light of patterns other than the wiring pattern of the uppermost layer is greater than a predetermined value in the second linearly polarized light; and a selected wavelength light component guiding step of guiding a light component in a wavelength region selected by the selecting step .

Therefore, in the wiring pattern detection method of the twenty-fifth aspect of the present invention, the above-mentioned means is adopted, and accordingly, in the second linearly polarized light, a wavelength region is selected in which the amount of reflected light of the uppermost layer wiring pattern has the same relationship with that of the uppermost layer wiring pattern. The difference between the amounts of reflected light of patterns other than the patterns is greater than a predetermined value, and an image composed of light components in the selected wavelength region can be picked up. Thus, an image visualized as an uppermost layer wiring pattern can be obtained.

According to the twenty-sixth aspect of the present invention, in the wiring pattern detection method of the twenty-fifth aspect of the present invention, the base film is formed of polyimide resin, the wiring pattern is formed of copper, and the selection step selects a wavelength region including 550 nm, And the image pickup step picks up an image through the CCD.

Therefore, in the wiring pattern inspection method of the twenty-sixth aspect of the present invention, the above-mentioned means is adopted, and accordingly, it is possible to detect with good accuracy the wiring pattern of the uppermost layer involving a workpiece formed of polyimide resin and copper, wherein the Polyimide resin and copper are typical materials for the base film and wiring pattern.

According to a twenty-seventh aspect of the present invention, in the nineteenth or twentieth wiring pattern inspection method, the workpiece is irradiated with elliptically polarized light instead of circularly polarized light.

Therefore, when the above device is employed in the wiring pattern inspection method of the twenty-seventh aspect of the present invention, the workpiece can be irradiated with not only circularly polarized light but also elliptically polarized light.

According to a twenty-eighth aspect of the present invention, in the wiring pattern detection method of any one of the nineteenth to twenty-seventh aspects, the light source includes a white light source.

Therefore, when the above device is employed in the wiring pattern detection method of the twenty-eighth aspect of the present invention, a white light source can be used as a light source without using any special light source.

According to a twenty-ninth aspect of the present invention, there is provided a wiring pattern inspection method including the step of: combining an image picked up by the wiring pattern inspection method according to any one of the nineteenth to twenty-eighth aspects with a predetermined order Compare with satisfactory images to check whether the uppermost wiring pattern is satisfactory.

Therefore, when the above-mentioned means is adopted in the wiring pattern inspection method of the twenty-ninth aspect of the present invention, whether or not the wiring pattern of the uppermost layer is satisfactory can be inspected with good accuracy.

Brief description of the drawings

FIG. 1 is a configuration explanatory diagram showing an example of a wiring pattern inspection apparatus according to a first embodiment;

2 is a configuration explanatory diagram showing an example of an inspection unit in the wiring pattern inspection apparatus according to the first embodiment;

FIG. 3 is a schematic diagram showing a relationship between an irradiation area and a linear area in a workpiece;

4A is a schematic diagram showing the principle for obtaining a wiring pattern image in which uppermost layer wiring pattern information is visualized;

4B is a schematic diagram showing the principle for obtaining a wiring pattern image in which uppermost layer wiring pattern information is visualized;

4C is a schematic diagram showing the principle for obtaining a wiring pattern image in which uppermost layer wiring pattern information is visualized;

4D is a schematic diagram showing the principle for obtaining a wiring pattern image in which uppermost layer wiring pattern information is visualized;

5A shows a picked-up image of a wiring pattern in the case where the rotation angle of the polarization filter is set to 0 degrees in the inspection unit shown in FIG. 2;

FIG. 5B shows a picked-up image of a wiring pattern in the case where the rotation angle of the polarization filter is set to 10 degrees in the inspection unit shown in FIG. 2;

FIG. 5C shows a picked-up image of a wiring pattern in the case where the rotation angle of the polarization filter is set to 45 degrees in the inspection unit shown in FIG. 2;

5D shows a picked-up image of a wiring pattern in the case where the rotation angle of the polarization filter is set to 80 degrees in the inspection unit shown in FIG. 2;

FIG. 5E shows a picked-up image of a wiring pattern in the case where the rotation angle of the polarization filter is set to 90 degrees in the inspection unit shown in FIG. 2;

6A shows an image of an uppermost layer wiring pattern picked up by an inspection unit according to the present invention with respect to a multilayer wiring substrate of a semiconductor package on which a three-layer inner layer wiring pattern is converged with respect to the uppermost layer wiring pattern. The imide insulating layer exists;

6B shows an image picked up by a conventional technique regarding a multilayer wiring substrate of a semiconductor package on which three inner layer wiring patterns exist through a polyimide insulating layer with respect to the uppermost layer wiring pattern;

7A shows an image of an uppermost layer wiring pattern obtained by an inspection unit according to the present invention with respect to a multilayer wiring substrate of a semiconductor package on which an inner layer wiring pattern is converged with respect to the uppermost layer wiring pattern. The imide insulating layer exists;

Fig. 7B shows the linear distribution corresponding to the image of Fig. 15;

Figure 8 shows an image obtained by binary processing of the image shown in Figure 15;

9 shows an example of a histogram of a wiring pattern image in a case where the rotation angle of the polarization filter of the inspection unit is changed in the wiring pattern inspection apparatus according to the first embodiment;

10 is a perspective view showing an example of the entire configuration of a polarizing beam splitter in a wiring pattern inspection apparatus according to a second embodiment;

11 is a perspective view showing an example of the entire configuration of another polarizing beam splitter in the wiring pattern inspection apparatus according to the second embodiment;

12 is a diagram showing the case (a) where the polarizing beam splitter is provided alone, the case (b) where the polarizing beam splitter includes a thin plate prism and a half-wavelength plate, and the case (b) where the polarizing beam splitter includes a total reflection mirror and a quarter-wavelength plate. A distribution diagram of a level difference along an arbitrary row of the wiring pattern portion in the image data picked up under the case (c);

13 is a configuration explanatory diagram showing an example of an inspection unit of a wiring pattern inspection apparatus according to a third embodiment;

14 is a configuration explanatory diagram showing an example of a parallel light guiding device in an inspection unit of a wiring pattern inspection apparatus according to a third embodiment;

15A is a configuration explanatory diagram showing an example of a light extraction section in an inspection unit of a wiring pattern inspection apparatus according to a third embodiment;

15B is a configuration explanatory diagram showing one example of a light extraction section in the inspection unit of the wiring pattern inspection apparatus according to the third embodiment;

15C is a configuration explanatory diagram showing one example of a light extraction section in the inspection unit of the wiring pattern inspection apparatus according to the third embodiment;

15D is a configuration explanatory diagram showing one example of a light extraction section in the inspection unit of the wiring pattern inspection apparatus according to the third embodiment;

16 is a perspective view showing a positional relationship between two stages of polarizing beam splitters arranged in series;

17 is a configuration explanatory diagram showing an example of a wavelength selection section in the inspection unit of the wiring pattern inspection apparatus according to the third embodiment;

18A shows an image showing an example of an uppermost layer wiring pattern picked up in a multilayer wiring substrate of a semiconductor package on which an inner layer wiring pattern exists;

18B shows an image showing an example of an uppermost layer wiring pattern picked up in a multilayer wiring substrate of a semiconductor package on which three inner layer wiring patterns exist;

19A shows an image showing an example of an uppermost layer wiring pattern picked up in a multilayer wiring substrate of a semiconductor package on which an inner layer wiring pattern exists;

Figure 19B shows an image obtained by binary processing of the image shown in Figure 19A;

FIG. 20 shows the line distribution in the width direction of the imaging field of view in an image in the case where two-stage polarizing beam splitters are combined in series and in an image in the case of combining a polarizing beam splitter and a transverse wave polarizing plate in order to increase polarization efficiency An example of

FIG. 21A is a diagram showing a case where there is no offset with respect to an applied incident angle at opposite ends of the polarizing beam splitter (a case where two-stage polarizing beam splitters are arranged in series);

FIG. 21B is an explanatory diagram of a shift (in a case where two-stage polarizing beam splitters are arranged in series) with respect to an applied angle of incidence at opposite ends of the polarizing beam splitter;

FIG. 22A is a diagram showing a case where there is no offset at opposite ends of the polarizing beam splitter with respect to an applied angle of incidence (a case where only one polarizing beam splitter is provided);

Fig. 22B is an explanatory diagram of a shift with respect to an applied incident angle at opposite ends of the polarizing beam splitter (the case where only one polarizing beam splitter is provided).

Best Mode for Carrying Out the Invention

Embodiments of the present invention will be described below with reference to the drawings.

first embodiment

A first embodiment of the present invention will be described below with reference to FIGS. 1-9.

FIG. 1 is a configuration explanatory diagram showing an example of a wiring pattern inspection apparatus according to the present embodiment.

That is, the wiring pattern inspection apparatus 200 according to the present embodiment is a wiring pattern inspection apparatus that optically inspects the wiring pattern of the uppermost layer of a workpiece 51 including a multilayer wiring substrate of a semiconductor package in which Form a wiring pattern. The apparatus includes an inspection unit 100 , a workpiece wind-out unit 110 , a management code readout unit 120 , a marking unit 130 , an inspection/verification unit 140 , a workpiece winding unit 150 and a host computer 160 .

In the workpiece unwinding unit 110, the workpiece reel 111 on which the workpiece 51 is wound is provided on the lower table, and the workpiece 51 is sent out by the roller 113 along the workpiece path of the lower table, and passed through the upper table set at the required/suitable position. /Lower limit sensor 122 to adjust the loosening amount. The isolation tape 52 for protection is wound on the isolation tape reel 112 , and the isolation tape 52 is wound together with the workpiece 51 on the workpiece reel 111 . Status information of the workpiece 51 is transmitted to the host computer 160 .

Next, the drive rollers 121a, 121b pass through the guide rollers 114, 115 by the belt to stabilize the workpiece 51 with high precision. In this state, the workpiece is transported to the management code reading unit 120, the management code (such as a mark in which the workpiece information is managed/encoded, etc.) is read by the CCD camera 123, and the read management code is transmitted to the host computer 160 .

Furthermore, the workpiece 51 is stabilized with high precision by conveying the drive rollers 121 a , 121 b via the guide rollers 116 , 117 by the belt. In this state, the workpiece is conveyed to the inspection unit 100 . The inspection unit 100 optically obtains the wiring pattern of the uppermost layer of the workpiece 51 . Also, the wiring pattern data obtained by extracting the characteristics of the obtained wiring pattern is compared with the normally designed wiring pattern data, and it is judged whether the wiring pattern is satisfactory or not. And, the judgment result is sent to the host computer 160 . Details of this inspection unit 100 will be described later.

The workpiece 51 whose wiring pattern has been judged to be satisfactory or unsatisfactory by the inspection unit 100 with high precision through the guide rollers 118, 119 is conveyed by the belt conveyance drive rollers 121a, 121b, and is conveyed in this state to marking unit 130 . The marking unit 130 perforates or marks the workpiece 51 as a defective product in order to identify the defective workpiece 51 . Also, this marking result is transmitted to the host computer 160 . It should be noted that examples of marking methods include printed marking, tapping, and methods other than perforation.

Next, in the inspection/verification unit 140, the wiring pattern is not only observed but also verified in order to confirm an excessive quality level. The result of this confirmation is transmitted to the host computer 160 .

Furthermore, when the re-inspection function is provided with a wiring pattern or a length measurement function of an arbitrary part such as a defective part, a length measurement unit can be realized in addition to the inspector. Accordingly, general information on the pattern width of a reel can be obtained and this contributes to an immediate feedback into the procedure.

Next, the workpiece 51 is transferred to the workpiece winding unit 150 via the guide rollers 141 , 142 . Also, the workpiece is wound together with the insulating tape 52 for protection provided by the insulating tape reel 152 in the workpiece reel 151 . The status information of the workpiece 51 in the workpiece winding unit 150 is transmitted to the host computer 160 .

The wiring pattern inspection apparatus 200 constituted in this way has a unit structure as a base. For example, addition/removal of units, such as adding the inspection unit 100, can be easily performed in order to increase the processing speed, and a structure or configuration is realized in consideration of use in a clean environment. Work conveyance or other configurations are not limited to the above modes. For example, the configuration could be implemented with vertical transport instead of transverse transport, with both the workpiece unwinding unit 110 and the workpiece winding unit 150 being located on the same side, or other arrangements could also be implemented.

Details of the inspection unit 110 will be described later.

As shown in Figure 2, the inspection unit 100 includes: a light source 10; a light guide 11; a condenser lens 12; a hot wire cutting filter 13; a heat radiation mechanism 14; ; a CCD device 31 ; a band-pass filter 32 ; an image forming lens 33 ; a polarization filter 34 (polarizing plate); a calculation control unit 40 ; It should be noted that each of condenser lens 12 and image forming lens 33 is not limited to a single lens, and may be a lens group including a plurality of lenses.

As the light source 10, a high-intensity lighting device that emits light in the entire visible range, such as a white light source and a metal halide lamp, is preferable. In order to pick up an image with high resolution by the CCD device 31 as described later, a sufficient amount of light is required. Therefore, as the light source 10, for example, a metal halide lamp with a rated power of 250W is changed to a metal halide lamp with a rated power of 350W. As the light guide 11, a spot type or rod lens capable of combining lights from a plurality of light sources 10 to emit output from one end is preferable. In addition, when the number of light sources 10 used increases, the bundled diameter or outer shape of the light guide 11 must be enlarged, and thus the condenser lens 12 needs to be designed. It is also necessary to take measures against the heat generated by the infrared light contained in the light from the light source 10 .

When light is emitted from the light source 10 , the light enters the polarizing beam splitter 21 through the light guide 11 , the condenser lens 2 , and the hot wire cut filter 13 . The hot wire cut filter 13 interrupts light on the long wavelength side (for example, a wavelength of 700 nm or more), and allows other light to enter the polarizing beam splitter 21 .

The light emitted from the light source 10 is so-called random light having light components in many directions. It should be noted that in this case, the "light guiding direction" is defined as the horizontal direction from right to left in the figure. The polarizing beam splitter 21 extracts linearly polarized light from this random light (the front and rear directions in the figure are electric field vector directions). Therefore, it is necessary to fully consider the applicable wavelength region, extinction ratio, polarization ratio, and the ability to illuminate the entire field of view of the workpiece or the external shape and size of the image to select a suitable polarizing beam splitter. The polarizing beam splitter 21 obtains linearly polarized light in this way, but does not necessarily extract 100% of the linearly polarized light, and also includes a small amount of light components whose electric field vectors are outside the front/rear direction in the figure.

It should be noted that the polarizing beam splitter 21 and the hot wire cutting filter 13 are at high temperature due to the light of the light source 10 . The heat radiation mechanism 14 is provided due to the risk of cracking, or degradation of the optical component itself. The heat radiation mechanism 14 ejects air from the outside, thereby cooling the polarizing beam splitter 21 and the hot wire cutting filter 13 . For example, when a 250W metal halide lamp is used as the light source 10, the hot wire cutting filter 13 is at a high temperature of about 75°C, but experimental examples obtained show that air is ejected from the heat radiation mechanism 14, thereby reducing the temperature to about 50°C.

Polarizing beam splitter 21 guides the extracted linearly polarized light to polarizing beam splitter 22 . At this time, the light component not guided to the polarizing beam splitter 22 escapes onto the side wall of the lens tube in the polarizing beam splitter 21, so it is necessary to apply thermal measures in the side wall portion. The gap between the polarizing beam splitters 21 and 22 is set as small as possible in order to minimize light propagation losses.

A small amount of light whose electric field vector is out of the front/rear direction is also included in the light guided from the polarizing beam splitter 21 , so it is removed by the polarizing beam splitter 22 . The light is directed further downwards. Also, the image forming lens 33 and the polarization filter 34 convert the linearly polarized light into light having an angular component of a rotation angle of 40 to 50°, and irradiate the workpiece 51 held by the workpiece fixing/driving mechanism 50 . The workpiece 51 is irradiated with light components obtained by vector-decomposing incident linearly polarized light according to the rotation angle. It should be noted that in FIG. 2 , the image forming lens 33 is disposed between the polarizing beam splitter 22 and the polarizing filter 34 , but the polarizing filter 34 may be disposed between the polarizing beam splitter 22 and the image forming lens 33 . The rotation mechanism may suitably be arranged in such a manner that the polarization filter 34 can easily select light comprising only certain angular components.

A light component for irradiating workpiece 51 is reflected by workpiece 51 , and a light component obtained by vector-decomposing the reflected light according to the rotation angle of polarizing filter 34 enters polarizing beam splitter 22 through polarizing filter 34 and image forming lens 33 . At this time, in polarizing beam splitter 22 , linearly polarized light whose electric field vector direction is in the light guiding direction is extracted, and this linearly polarized light enters bandpass filter 32 .

The band-pass filter 32 extracts the wavelength region in which the difference between the amount of reflected light of the uppermost layer wiring pattern and the amount from the polarizing beam splitter 22 generated by the reflected light passing through the polyimide insulating layer portion is the largest , and only the light of the extracted wavelength region enters the CCD device 31 in the sensor camera 30 .

In this embodiment, line sensor technology is applied to the sensor camera 30 . Figure 3 is a schematic diagram illustrating line sensor technology. That is, in the sensor camera 30 , of the light that has entered the CCD device 31 through the bandpass filter 32 , only light corresponding to a linear region predetermined as the specification of the CCD device 31 is imaged by the CCD device 31 . In FIG. 3 , a circular irradiation area 71 indicates an area of the workpiece 51 irradiated with the light component. Each of the aforementioned linear regions 72 is set in such a manner as to pass through the center of each irradiation region 71 . When the flatness of the workpiece 51 is ensured within the depth of focus of the image forming lens 33 by the workpiece fixing/driving mechanism 50 for the workpiece 51 and the irradiation area 71 that is a part of the workpiece 51 is irradiated with a light component, in which In a state where the optical head of the sensor camera 30 or the workpiece fixing/driving mechanism 50 is adjusted in the direction, the CCD device 31 picks up an image. Accordingly, the sensor camera 30 images the light in a linear area 72 corresponding to the illuminated area 71 .

When imaging the light in a certain linear region 72 in this way, the workpiece fixing/driving mechanism 50 is driven, and the workpiece 51 is moved slightly, for example, as shown by the arrow in FIG. move. Also, the light in the linear region 72 corresponding to the irradiation region 71 is likewise imaged. The minute movement and imaging of the workpiece 51 are continued until the linear area 72 covers the entire surface of the workpiece 51 . Also, when the respective imaged linear regions 72 are superimposed on each other to thereby obtain imaging information on the entire surface of the workpiece 51 , a wiring pattern image in which uppermost layer wiring pattern information is obtained is obtained.

Since the wiring pattern of the workpiece 51 constituting the object is at least 10 μm and is fine, the sensor camera 30 and the image forming lens 33 optically designed in such a way that the picked-up image has high resolution are used. The resolution is preferably about 1 to 2 μm, whereby pattern edge information can be obtained clearly enough, but this resolution setting is aimed at about 1/9 to 1/10 of the pattern width as an object. Since the imaging field of view also varies with the number of devices and the resolution of the CCD device 31 with respect to the sensor camera 30 used, it is necessary to fully study the resolution. For example, in the case of realizing a resolution of 1 μm by the CCD device 30 having 8000 pixels, the imaging field of view is 8 mm.

Also, assuming that the size of the CCD device 31 is 7 μm, seven times optical magnification is naturally required. The resolving power obtained at this time is 721p (line pair)/mm on the object side. In order to realize a resolution of 1 μm, an image cannot be picked up with equal luminance unless there is about 50 times the amount of light in terms of an area ratio with respect to a resolution of 7 μm. A logical sum with various conditions is required in an optical system.

Also, in the bandpass filter 32, for example, as in the dichroic green filter, a filter having a wavelength region in which the amount of reflected light of the wiring pattern of the uppermost layer is related to the concentration and high transmittance is used. The difference between the amounts of reflected light at the imide insulating layer portions was the largest. Specifically, when focusing on the wavelength of 550 nm as the green light component, the reflection spectral sensitivity of copper is 3%, while the reflection spectral sensitivity of the polyimide layer is 0.1%, and as obtained from the experimental value, the reflectance 30 times the light.

That is, since the intensity of the light component reflected by the workpiece 51 depends on copper and polyimide, and copper has stronger reflection intensity, the uppermost wiring pattern portion can be imaged brightly. When the workpiece 51 is irradiated, the polarization ratio increases, the wiring pattern and the polyimide insulating layer are irradiated, and accordingly the image of the uppermost wiring pattern is picked up more clearly.

The wiring pattern data of the wiring pattern image in which the wiring pattern information of the uppermost layer is obtained in this way is output to the calculation control unit 40, which includes a personal computer, keyboard, mouse, display, etc. displayed on the monitor. In the calculation control unit 40, various calculation, identification and comparison processes are performed using the output wiring pattern data and the standard design wiring pattern data, and it is judged whether the wiring pattern is satisfactory or not. The computer control unit 40 also functions as a user interface, which controls the workpiece fixing/driving mechanism 50 and the like.

Next, the operation of the inspection unit of the wiring pattern inspection apparatus according to the present embodiment configured as described above will be described.

That is, in the inspection unit 100 , when light is emitted from the light source 10 , the light is guided to the hot wire cutting filter 13 via the light guide 11 and the condenser lens 12 . Also, light on the long-wavelength side (for example, a wavelength of 700 nm or more) is interrupted by the hot wire cut filter 13 , and the other light is guided into the polarizing beam splitter 21 .

The light emitted from the light source 10 is random light, and linearly polarized light (the front/rear direction in the figure is the electric field vector direction) is extracted from the random light in the polarizing beam splitter 21 and guided to the polarizing beam splitter 22. It should be noted that 100% linearly polarized light does not need to be extracted by polarizing beam splitter 21 (the front/rear direction in the figure is the electric field vector direction) and includes a slight amount of electric field vectors other than the front/rear direction in the figure Light component.

It should be noted that the polarizing beam splitter 21 and the hot wire cutting filter 13 are at a high temperature due to light from the light source 10 and are cooled by air blown out from the heat radiation mechanism 14 .

A small amount of light containing an electric field vector other than the front/rear direction is included in the light guided from the polarizing beam splitter 21 , and thus is removed by the polarizing beam splitter 22 . Also, the light is guided to the image forming lens 33 and the polarization filter 34 . Further, the workpiece 51 is irradiated with linearly polarized light extracted by the polarizing beam splitter 22 , in which a predetermined deflection component obtained through the polarization filter 34 having a predetermined angle is fixed by the workpiece fixing/driving mechanism 50 .

The workpiece 51 reflects the light component with which the workpiece 51 is irradiated, and the reflected light passes through the polarization filter 34, and is converted into linearly polarized light perpendicularly intersecting with the electric field vector direction of the linearly polarized light (the right/left direction in the figure is the electric field direction ).

Thereafter, the light is formed into parallel light by the image forming lens 33 , and the linearly polarized light whose electric field vector direction is the right/left direction in the drawing is extracted by the polarizing beam splitter 22 and then guided to the bandpass filter 32 .

In the band pass filter 32, the wavelength region in which the difference between the reflected light quantity of the uppermost layer wiring pattern and the reflected light quantity of the polyimide insulating layer portion is maximized is extracted, and only the light of the wavelength region is transmitted to the sensor camera CCD device 31 in 30. Specifically, in a wavelength of 550 nm as a green light component, the reflectance spectral sensitivity of the polyimide layer is 0.1%, while that of copper is 3%, and 30-fold reflection is obtained from the experimental value. When the light extracted in this way is imaged by the CCD device 31, an image of a wiring pattern whose uppermost layer wiring pattern information has been visualized is obtained. That is, since the intensity of the light component reflected by the workpiece 51 depends on copper and polyimide, and copper has stronger reflection intensity, the uppermost copper pattern portion is imaged brightly. When the workpiece 51 is irradiated, the polarization ratio is increased, the wiring pattern and the polyimide insulating layer are irradiated, and accordingly a clearer image of the uppermost wiring pattern is picked up.

This principle will be described below with reference to FIGS. 4A and 4B. That is, linearly polarized light Y ₁ whose electric field vector direction is in the front/rear direction in FIG. The plate or polarizing beam splitter directs the light L from the light source 10 in parallel. 4A and 4B show an example in which linearly polarized light Y ₁ is extracted and guided by a polarizing beam splitter 21 .

Also, the light is guided to a polarizing plate 65, the optical axis of which is adjusted at an arbitrary angle with respect to the linearly polarized light _Y1 . The optimal angle of the polarizing plate (the optimal angle formed by the front/rear direction of FIG. 2 and the transmission axis of the polarizing plate 65 ) with respect to the linearly polarized light Y1 at this time is 45 degrees. Therefore, the effect under the condition of 45 degrees will be described later.

线性偏振光Y₂照射其中布线图案69设置在聚酰亚胺膜绝缘材料等的基底67上的工件51。In addition, light transmitted through the polarizing plate 65 whose optical axis has been adjusted to 45 degrees constitutes a The multiplier vector decomposes the components obtained by incident linearly polarized light Y1. use the

The linearly polarized light _Y2 irradiates the workpiece 51 in which the wiring pattern 69 is provided on a base 67 of polyimide film insulating material or the like.

线性偏振光Y₂照射铜等的布线图案69时，通过由铜电镀装置等形成的铜等的布线图案69的表面简单地反射入射

线性偏振光Y₂。而且，被反射的

线性偏振光Y₃再次通过偏振板65。此时，关于通过偏振光束分光器21的光Y₄，通过将由工件51反射的

线性偏振光Y₃进行再次

矢量分解得到的分量在偏振光束分光器21的上方通过。该光分量Y5作为具有最上层的布线图案69的信息的分量由CCD装置31接收。As shown in Figure 4A, when using the

When the linearly polarized light _Y2 irradiates the wiring pattern 69 of copper or the like, the incident light is simply reflected by the surface of the wiring pattern 69 of copper or the like formed by a copper plating device or the like.

Linearly polarized light Y ₂ . Moreover, the reflected

The linearly polarized light Y ₃ passes through the polarizing plate 65 again. At this time, regarding the light Y ₄ passing through the polarizing beam splitter 21 , the light Y 4 reflected by the workpiece 51 passes through

Linearly polarized light Y ₃ conducts again

The components obtained by vector decomposition pass above the polarizing beam splitter 21 . This light component Y5 is received by the CCD device 31 as a component having information on the uppermost wiring pattern 69 .

线性偏振光Y₂，其中通过膜的表面为其增加角度变化。由于反射的光Y₃’偏离偏振板45度的角度，因此光具有如此程度的光量以至于与由CCD装置31在45度时接收的0.5的相对光量相比几乎不接收光。即，在照射铜等的布线图案69的情况和照射聚酰亚胺绝缘部分的透明基膜67的情况之间形成由CCD装置31接收的光量差。应该几乎不把对应于聚酰亚胺膜绝缘材料等的透明基膜67的信息分量引导到CCD装置31。Likewise, as shown in Figure 4B, with the The linearly polarized light _Y2 irradiates a transparent base film 67 of polyimide film insulating material or the like. It is seen that the transparent base film 67 has anisotropy in material properties. That is to say, it is recommended that the reflection incident on the transparent base film 67 as polarized light or random light

Linearly polarized light _Y2 with an angular change added to it passing through the surface of the film. Since the reflected light Y ₃ ′ deviates from the polarizing plate at an angle of 45 degrees, the light has such an amount of light that almost no light is received compared to the relative light amount of 0.5 received by the CCD device 31 at 45 degrees. That is, a difference in the amount of light received by the CCD device 31 is formed between the case of irradiating the wiring pattern 69 of copper or the like and the case of irradiating the transparent base film 67 of the polyimide insulating portion. The information component corresponding to the transparent base film 67 of polyimide film insulating material or the like should be hardly guided to the CCD device 31 .

Therefore, when information is well extracted according to the characteristics of the material forming the semiconductor package in this way, and received by the CCD device 31, it is possible to pick up the uppermost layer wiring pattern information as an image with high contrast while not reflecting the inner layer wiring pattern .

Moreover, FIG. 6A shows an image showing an example of the uppermost layer wiring pattern picked up by the sensor camera 30 after the uppermost layer wiring pattern information is obtained by the inspection unit 100 with respect to the multilayer wiring substrate of the semiconductor package, Wherein there are three inner layer wiring patterns on the wiring substrate with respect to the uppermost layer wiring pattern via the polyimide insulating layer. On the other hand, FIG. 6B shows an image generally picked up by a camera with respect to the same uppermost layer wiring pattern.

From FIGS. 6A and 6B , it can be confirmed that the wiring pattern information of the uppermost layer is obtained optically by the inspection unit 100 , and accordingly, the wiring pattern of the uppermost layer can be clearly extracted even when there are three inner layer wiring patterns. A unique uppermost layer wiring pattern can be extracted regardless of the existence of the wiring pattern regardless of increasing the number of inner layers.

On the other hand, as shown in FIG. 6B , the wiring patterns of all layers are reflected in normal imaging by a camera. Furthermore, since the uppermost layer wiring pattern has the same luminance as that of the inner layer wiring pattern, the pattern is not separated even when, for example, binary processing is performed. In particular, the influence is conspicuous in a portion where the uppermost layer wiring pattern intersects with the inner layer wiring pattern, and it is not easy to recognize the pattern existing on the uppermost side.

Moreover, FIG. 7A shows an image showing another example of the uppermost layer wiring pattern picked up by the CCD device 31 after the uppermost layer wiring pattern information is obtained by the inspection unit 100 with respect to the multilayer wiring substrate of the semiconductor package. , wherein an inner layer wiring pattern exists in the wiring substrate via a polyimide insulating layer with respect to the uppermost layer wiring pattern. FIG. 7B shows a line distribution corresponding to the wiring pattern portion shown in the image in FIG. 7A. FIG. 8 shows an image obtained by binary processing with respect to the image shown in FIG. 7A.

As is apparent from FIG. 8, the uppermost layer wiring pattern portion is bright, and the inner layer pattern and polyimide insulating layer portions are imaged very darkly. In this way, the image picked up by the inspection unit 100 can be further divided into the uppermost layer wiring pattern and the inner layer wiring pattern by simple image processing called binary processing without being affected by the inner layer wiring pattern. Also, CAD data (pattern design information) or a satisfactory workpiece (a workpiece in which a wiring pattern is correctly formed) is set in advance as a reference master image, and can have a difference by comparison with a binary image, a characteristic extraction method, etc. Part of it is judged as a defect.

Also, the best image for pattern inspection represents a state where pattern edges are clear and without any influence of surface irregularities. The contrast difference between the wiring pattern part and the polyimide insulating layer part must be clearly separated so that the pattern edge should be clear. Therefore, the amount of light with which the workpiece is irradiated must be large, and the workpiece must be bright in order to eliminate the influence of surface irregularities of the wiring pattern.

9 shows an example of a histogram of the wiring pattern image in the case where the transmission axis of the polarization filter 34 is changed by a predetermined angle in the direction of the electric field vector of the first linearly polarized light, wherein the abscissa represents the level value and the ordinate represents the number of pixels. The condition for the maximum shift of the histogram on the high-grade side is a rotation angle of 40 to 50 degrees, and it is confirmed that the area of the peak of the histogram is also reduced at this rotation angle as compared with the other rotation angles.

A polyimide insulating layer portion or a wiring pattern portion is included within the range of the peak at another rotation angle. However, the wiring pattern portion has the largest level when approaching the optimum angle. Therefore, the wiring pattern part is separated from the area of the peak, and the area of the peak is reduced. Also from the images picked up at each rotation angle, it is confirmed that the optimum condition is a rotation angle in the range of 40 to 50 degrees, in which the wiring pattern part is clear, and the wiring pattern part and The contrast difference between the polyimide insulating layer parts is large.

At other rotation angles, the gradation value of the wiring pattern portion decreases, and accordingly, the contrast difference between the wiring pattern portion and the polyimide insulating layer portion decreases. Thus, the gradation value of the wiring pattern portion is lowered, and the influence of the irregularity of the wiring pattern surface also remarkably appears. Therefore, this image is not suitable as a pattern inspection image. Images of the various angular components are shown in Figures 5A and 5E.

As described above, in the wiring pattern inspection apparatus according to the present embodiment, the influence of the inner layer wiring pattern can be optically removed in the multilayer wiring substrate of the semiconductor package by the above function. As a result, a fine image of the wiring pattern of the uppermost layer can be picked up.

Furthermore, when the image is compared with reference data or a reference image, inspection of wiring patterns can be automatically performed with high reliability.

Also, when the line sensor technology is applied to the sensor camera 30, an image can be picked up in a short time compared to the case of obtaining an image by applying spot scanning, for example, as in Jpn. Pat. No. 2962565. Therefore, this technique is advantageous even for an uppermost layer wiring pattern having a large area.

Furthermore, since the wiring pattern can be inspected on the basis of the image picked up by the sensor camera 30, it is not necessary to doubly provide an inspection system, as in Jpn. Pat. No. 2962565, and the configuration can be simplified. In addition, since the data processing of the detected value is also reduced, the load on the calculation control unit 40 can be reduced.

second embodiment

Next, a second embodiment of the present invention will be described with reference to FIGS. 2 and 10-12.

The wiring pattern inspection apparatus according to the present embodiment involves improvement of the polarizing beam splitter 21 in the inspection unit 100 of the wiring pattern inspection apparatus according to the first embodiment. Therefore, here, only the polarizing beam splitter 21 will be explained.

That is, in the first embodiment of FIG. 2, the polarizing beam splitter 21 extracts linearly polarized light from the random light emitted from the light source 10 (the front/rear direction in the figure is the electric field vector direction). However, the light component in which the vertical direction in FIG. 2 is the direction of the electric field vector escapes from the polarizing beam splitter 21 to the side at the time of extraction, and thus the side is at a high temperature.

Therefore, when this light component can be recovered, converted into a light component whose electric field vector direction is the front/rear direction in the figure, and guided to the polarizing beam splitter 22, the amount of light is further increased, and the wiring pattern portion and focusing can be enlarged. The difference in contrast between imide insulating layer sections.

FIG. 10 is a perspective view showing an example of the entire configuration of the polarizing beam splitter 21 for realizing the present embodiment.

That is, as shown in FIG. 10, the polarizing beam splitter 21 of this embodiment includes a polarizing film 21a, and furthermore, a sheet prism 23(#R) and a sheet prism 23(#L) are provided on opposite sides. A half-wavelength plate 24 is provided above.

That is, when the random light is introduced into the polarizing beam splitter 21 from the light source 10, the light component Y whose electric field vector direction is the front/rear direction in the figure is extracted from the random light by the polarizing beam splitter 21, and guided to Polarizing beam splitter 22. On the other hand, at the time of this extraction, the light component T whose electric field vector direction is the vertical direction in FIG. 2 escapes from the side and is introduced into the sheet prism 23 (#R). Sheet prism 23 (#R) receives light component T that has escaped and whose electric field vector direction is the vertical direction in FIG. 2 , and guides the component to half-wavelength plate 24 . The half-wavelength plate 24 converts the light component T introduced from the sheet prism 23 (#R) by half-wavelength and whose vertical direction in FIG. 2 is the electric field vector direction. That is, this component is converted into a light component Z whose electric field vector direction is the right/left direction in the figure, and guided to the sheet prism 23 (#L). The sheet prism 23 (#L) guides the light component Z into the polarizing beam splitter 21 from the side, wherein the direction of its electric field vector guided from the half-wavelength plate 24 is the right/left direction in the figure. The polarizing film 21a reflects the light component Z whose electric field vector direction guided in this way is the right/left direction in the figure, and correspondingly converts this component into the light component Y whose electric field vector direction is the front/left direction in the figure in the rear direction, and direct this component out to a polarizing beam splitter 22.

FIG. 11 is a perspective view showing an example of the overall configuration of a polarizing beam splitter 21 performing a similar function.

In the configuration shown in FIG. 11, the polarizing beam splitter 21 includes a polarizing film 21a, in addition, a total reflection mirror 26 (#L) is provided on the side of the polarizing film 21a on the non-reflecting surface side, and a total reflection mirror 26 (#L) is provided on the reflecting surface side. A quarter-wavelength plate 25 and a total reflection mirror 26 (#R) are provided on the side of the polarizing film 21a.

That is, when random light is introduced from the light source 10 into the polarizing beam splitter 21, the light component Y whose electric field vector direction is the front/rear direction in the figure is extracted from the random light, and guided to the polarizing beam splitter 22 in. On the other hand, at the time of this extraction, the light component T whose vertical direction is the direction of the electric field vector in FIG. .

The total reflection mirror 26 (#R) reflects the light component T, whose vertical direction in Fig. 2 guided in this way is the electric field vector direction, and accordingly introduces this component into the polarized beam splitter through the quarter-wavelength plate 25 device 21. Thus, the light component T which has escaped from the polarizing beam splitter 21 and whose vertical direction is the direction of the electric field vector in FIG. , the direction of the electric field vector of the light component Z is the right/left direction in the figure.

Further, the light component Z whose electric field vector direction is the right/left direction in FIG. 2 passes through the polarizing film 21a, comes out of the polarizing beam splitter 21 once, and reaches the total reflection mirror 26 (#L). Also, this component is reflected by the total reflection mirror 26 (#L), then goes through the polarizing beam splitter 21 again, and is reflected by the polarizing film 21a. Accordingly, this component is converted into a light component Y whose electric field vector direction is the front/rear direction in the figure, and guided into the polarizing beam splitter 22 .

Fig. 12 shows the situation (a) where polarizing beam splitter 21 is set separately, polarizing beam splitter 21 includes the situation (b) of sheet prism 23 and half-wavelength plate 24 as shown in Fig. 10 and polarizing beam splitter 21 A distribution diagram of level difference along an arbitrary line of a wiring pattern portion in image data picked up under the same conditions in the case (c) including the total reflection mirror 26 and the quarter-wave plate 25 shown in FIG. 11 .

There is almost no difference between (a) and (b), but in (a) and (c), a maximum contrast amplification effect of about 20% (brightness expansion of the wiring pattern portion and the insulating layer portion) can be confirmed.

In the wiring pattern inspection apparatus according to the present embodiment, as described above, not only the light component Y extracted by the polarizing beam splitter 21 and having the electric field vector direction which is the front/rear direction in the figure, but also the light component Y extracted by the The light component Y converted from the light component T whose vertical direction is the electric field vector and has the direction of the electric field vector which is the front/rear direction in the figure is guided out to the polarizing beam splitter 22 . Thus, since the light from the light source 10 can be efficiently used, the amount of light can be increased. As a result, since the difference in contrast between the wiring pattern portion and the polyimide insulating layer portion can be enlarged, the uppermost wiring pattern can be imaged more clearly.

third embodiment

Next, a third embodiment of the present invention will be described with reference to Figs. 13 to 22B.

The present embodiment relates to a modification of the inspection unit 100 of the wiring pattern inspection apparatus according to the first embodiment. Therefore, here, only the inspection unit will be explained.

FIG. 13 is a configuration explanatory diagram showing one example of an inspection unit of the wiring pattern inspection apparatus according to the present embodiment.

That is, the inspection unit in the wiring pattern inspection apparatus according to the present embodiment includes the parallel light guide part 56 , the light extraction part 58 , the wavelength selection part 60 , the workpiece fixing/driving mechanism 50 and the calculation control unit 40 .

Furthermore, as shown in FIG. 14 , the parallel light guide member 56 includes a light source 10 , a light guide 11 , a thermal wire cutting filter 13 , a condenser lens 17 , a diffusion plate 18 , a condenser lens 19 and a fan 20 .

The light source 10 may be a high-intensity illuminating device emitting light in the entire visible light range, such as a metal halide lamp, or an illuminating device emitting light with a single wavelength, such as a laser.

Light emitted from the light source 10 enters the condenser lens 17 through the light guide 11 and the hot wire cut filter 13 . Also, the condensing lens 17 , the diffuser plate 18 , and the condensing lens 19 convert the light into uniform parallel light, which is then guided to the light extraction part 58 . It should be noted that each condensing lens 17 and 19 is not limited to a single lens, and may be a lens group including a plurality of lenses.

The light guided to the light extraction part 58 must be uniform parallel light. This is because the characteristics of the optical polarizing means used in the light extraction means 58 are sensitive, inter alia, depending on the light incident angle, and greatly affect the desired wavelength characteristics in the case of light incidence other than light with an applied incident angle.

For example, when a polarizing beam splitter 68 (described in detail later) is applied to the light extraction part 58, when a test is performed on a 40-degree incident with respect to the polarizing beam splitter 68 having the standard incident angle of 45 degrees, in the wavelength region used An experimental value of 2% light reduction was obtained in . When tested at 50 degrees of incidence, the light was reduced by 38%. Accordingly, gradient curves (shading) with high brightness are produced in the imaging field of view.

Various image processing and recognition processing are performed on an image in which this large gradient curve exists, and this causes an increase in time for processing by the calculation control unit 40 . Furthermore, when there are defects of the same type, for example, in the middle and at the ends of the image due to the presence of gradient curves, there is a risk of differences in the way in which the defects or contrast of the corresponding parts are viewed. Therefore, sufficient attention must be paid to the configurations of condensing lens 17, condensing lens 19, and diffusion plate 18 to be described later in such a manner that the light guided to light extraction member 58 must be uniform parallel light.

The diffuser plate 18 must be selected particularly comprehensively in consideration of the heat-resistant temperature, and fulfills the function of setting the distribution of the amount of emitted light from the light guide 11 to be uniform. A holographic diffuser is the most effective optical component as a diffuser plate, but has difficulties in terms of heat resistance. Therefore, opal is suitable where higher heat resistance is required.

Also, in general, the central portion of the distribution of the amount of emitted light from the end portion of the light guide 11 tends to be dark. The effect was obtained from experiments in which the lamps (not shown) in the light source 10 were tilted at an angle of 5 to 6 degrees in order to reduce the tendency to darken in the middle.

A fan 20 is provided instead of the heat radiation mechanism 14 in the first embodiment, and may not be provided as long as air can be sent to the light guide 11 to thereby air cool the guide and thermal measures are not required.

The light extraction member 58 has an upright portion configuration as shown in any one of FIGS. 15A to 15D . This part extracts linearly polarized light (assuming that the front/rear direction in the figure is the electric field vector direction) from randomly incident light guided by the parallel light guiding member 56 , further converts the light into circularly polarized light, and then irradiates the workpiece 51 . That is, in FIGS. 15A to 15D , incident light is guided from the right side of the light extraction member 58 , and the workpiece 51 disposed below the light extraction member 58 is irradiated with circularly polarized light.

The light extraction part 58 constituted as shown in Fig. 15A includes: a polarizing plate 61, whose transmission axis is the front/rear direction in the figure; a half mirror 62; a quarter-wavelength plate 64; and a polarizing plate 66, whose transmission axis In the right/left direction in the figure. In this case, the polarizing plate 61 whose transmission axis is in the front/rear direction in the figure extracts a light component whose electric field vector direction is the front/rear direction in the figure from incident light guided by the right side of the figure. The light component whose electric field vector direction is the front/rear direction in the figure is reflected downward in the figure by the half mirror 62 and then converted into circularly polarized light by the quarter-wave plate 64 to irradiate the workpiece 51 . This circularly polarized light is reflected by the workpiece 51, and constitutes circularly polarized light whose rotational direction is reversed. The reflected light is converted by the quarter-wavelength plate 64 into a light component whose electric field vector direction is the right/left direction in the figure. In addition, after the light passes through the half mirror 62 , the ratio of the linearly polarized light component is further increased due to the polarizing plate 66 , after which the light is guided to the wavelength selection member 60 .

The light extraction component 58 shown in FIG. 15B includes a polarizing beam splitter 68 and a quarter-wavelength plate 64 . In this case, the polarizing beam splitter 68 extracts the light component whose electric field vector direction is the front/rear direction in the figure from the incident light guided by the right side in the figure, and further divides the electric field vector direction of which is the The light components in the front/rear direction of the light are introduced into the quarter-wavelength plate 64 . This light component whose electric field vector direction is the front/rear direction in the figure is converted into circularly polarized light by the quarter-wave plate 64 , thereby irradiating the workpiece 51 . This circularly polarized light is reflected by the workpiece 51, and constitutes circularly polarized light whose rotational direction is reversed. The reflected light is converted by the quarter-wavelength plate 64 into a light component whose electric field vector direction is the right/left direction in the figure. After the light passes through the polarizing beam splitter 68 , the light is further guided to the wavelength selection member 60 .

The light extraction part 58 shown in FIG. 15C includes a polarizing beam splitter 70 , a polarizing beam splitter 68 , and a quarter-wavelength plate 64 . The positional relationship between the polarizing beam splitters 70 and 68 is shown in the perspective view of FIG. 16 . In this case, the polarizing beam splitter 70 extracts the light component whose electric field vector direction is the front/rear direction in the figure from the incident light guided by the right side in the figure, and further guides the light to the polarizing beam splitter 68. Polarizing beam splitter 68 reflects this linearly polarized light and allows the light to enter quarter wave plate 64 . This linearly polarized light is converted into circularly polarized light by the quarter-wave plate 64 to irradiate the workpiece 51 . This circularly polarized light is reflected by the workpiece 51, and constitutes circularly polarized light whose rotational direction is reversed. The reflected light is converted by the quarter-wavelength plate 64 into a light component whose electric field vector direction is the right/left direction in the figure. After the light passes through the polarizing beam splitter 68 , the light is further guided to the wavelength selection member 60 .

The light extraction part 58 shown in FIG. 15D includes a polarizing plate 61 , a polarizing beam splitter 68 and a quarter-wavelength plate 64 . In this case, the polarizing plate 61 extracts a light component whose electric field vector direction is the front/rear direction in the figure from incident light guided from the right side in the figure, and guides the light to the polarizing beam splitter 68 . Polarizing beam splitter 68 reflects this linearly polarized light and allows the light to enter quarter wave plate 64 . In this process, impurities contained in the incident light are also removed. Accordingly, linearly polarized light with higher purity is guided to the quarter-wave plate 64 .

This linearly polarized light is converted into circularly polarized light by the quarter-wave plate 64 to irradiate the workpiece 51 . This circularly polarized light is reflected by the workpiece 51, and constitutes circularly polarized light whose rotational direction is reversed. The reflected light is converted by the quarter-wavelength plate 64 into a light component whose electric field vector direction is the right/left direction in the figure. After the light passes through the polarizing beam splitter 68 , the light is further guided to the wavelength selection member 60 .

These polarizing plates 61, half mirrors 62, quarter-wavelength plates 64, and polarizing plates 66 must be selected in full consideration of the applied wavelength region, extinction ratio, polarization ratio, and the external shape and size that can illuminate the entire workpiece field of view or form an image. , polarizing beam splitter 68 and polarizing beam splitter 70. The light component with which the workpiece 51 is not irradiated escapes to the side wall in the lens tube, depending on the configuration, so a heat-resistant plate or an air cooling mechanism is provided in the side wall portion.

As shown in FIG. 17 , the wavelength selection section 60 includes a sensor camera 30 , a CCD device 31 , a bandpass filter 32 , a telecentric image side image forming lens 36 , and a telecentric object side image forming lens 38 .

That is, the workpiece 51 is irradiated with the circularly polarized light from the light extraction part 58 via the telecentric object side image forming lens 38 . Also, the reflected light obtained by reflecting circularly polarized light by the workpiece 51 is converted by the light extraction part 58 through the telecentric object side image forming lens 38 into a light component whose electric field vector direction is the right/left direction in the figure, and then through the telecentric The image side image forming lens 36 constitutes parallel light, passes through the light extraction part 58 , and then enters the bandpass filter 32 .

It should be noted that in the present invention, the light with which the workpiece is irradiated is not limited to fully circularly polarized light, and elliptically polarized light may also be used as long as the wiring pattern of the uppermost layer of the workpiece is mainly observed.

Next, the operation of the inspection unit of the wiring pattern inspection apparatus according to the present embodiment constituted as described above will be described below.

That is, in the inspection unit, when visible light or laser light is emitted from the light source 10 , the light is guided to the condenser lens 17 via the light guide 11 and the hot wire cutting filter 13 . Furthermore, after the light is converted into a uniform parallel light beam by the condenser lens 17 , the diffusion plate 18 and the condenser lens 19 , the light is guided to the light extraction member 58 .

Although the light guide 11 is heated by the light from the light source 10, the air is sent by the fan 20 and cools the guide before reaching a temperature at which the function deteriorates.

The work 51 is irradiated by further converting the light guided to the light extraction part 58 into circularly polarized light from which the linearly polarized light is extracted in the light extraction part part 58 (the former in the figure). /back direction is the electric field vector direction).

The workpiece 51 is irradiated with this circularly polarized light through the telecentric object side image forming lens 38 , and the light is reflected by the workpiece 51 . After passing through the telecentric object side image forming lens 38, the reflected light is converted by the light extraction part 58 into a light component whose electric field vector direction is the right/left direction in the figure, and is converted by the telecentric image side image forming lens 36 for parallel light. After passing through polarizing beam splitter 22 , the light is directed to bandpass filter 32 .

In the band-pass filter 32, a wavelength region in which the difference between the reflected light quantity of the uppermost layer wiring pattern and the reflected light quantity of the polyimide insulating layer portion is maximized is extracted, and only the light of this wavelength region is introduced into the sensor In the CCD device 31 in the camera 30. Specifically, in a wavelength of 550 nm as a green light component, the reflectance spectral sensitivity of the polyimide layer was 0.1%, while that of copper was 3%, and 30-fold reflection was obtained from the experimental value.

Therefore, when the incident light is imaged by the sensor camera 30 , an image of the wiring pattern is obtained, in which uppermost layer wiring pattern information is obtained. That is, since the intensity of circularly polarized light reflected by the workpiece 51 depends on copper and polyimide, and copper has stronger reflection intensity, the uppermost wiring pattern portion is imaged brightly. It should be noted that when the workpiece 51 is irradiated with circularly polarized light, the polarization ratio increases, the wiring pattern and the polyimide insulating layer are irradiated, and accordingly, the image of the uppermost wiring pattern is picked up more clearly.

This principle will be explained with reference to Figs. 4C and 4D. That is, linearly polarized light y ₁ whose electric field vector direction is in the front/rear direction in FIG. A polarizing plate or a polarizing beam splitter guides the light L from the light source 10 in parallel. 4C and 4D show an example in which the linearly polarized light y ₁ is extracted and guided by the quarter-wave plate 64 .

The linearly polarized light _y1 passes through the quarter-wavelength plate 64 and is correspondingly converted into circularly polarized light _y2 due to optical characteristics, and the substrate 67 comprising a polyimide film insulating material is irradiated with this circularly polarized light _y2 The wiring pattern 69.

As shown in FIG _{. 4C, when the wiring pattern 69 of copper or the like is irradiated with this circularly polarized light y2, incident circularly polarized light y2 as circularly} polarized light _y3 whose rotation direction is determined by The surface of the wiring pattern 69 of copper or the like formed by a copper plating device or the like is reversed. Moreover, when _the reflected circularly polarized light y ₃ passes through the quarter-wavelength plate 64 again, the light is converted into linearly polarized light y ₄ , which intersects the incident linearly polarized light y ₁ perpendicularly in terms of optical properties. . The converted linearly polarized light _y4 passes above the optical characteristic of the polarizing beam splitter 21, and is received by the CCD device 31 as a component _y5 having uppermost layer wiring pattern information.

Also, as shown in FIG. 4D, this circularly polarized light _y2 is irradiated with a transparent base film 67 of polyimide film insulating material or the like. It is seen that the transparent base film 67 has anisotropy in material properties. That is, the circularly polarized light _y2 introduced into the transparent base film 67 is reflected as elliptically polarized light y3' whose phase difference has been generated on the surface of the film. Also, when the elliptically polarized light y3' passes through the quarter-wavelength plate 64 again, the light is converted into linearly polarized light y4' having an azimuth angle according to the ellipticity of the elliptically polarized light. , the linearly polarized light y4' is due to the optical characteristics of the polarizing beam splitter 21 (actually, the component converted from the quarter-wavelength plate 64 to the linearly polarized light y4' only transmits the vector passing through the polarizing beam splitter 21 - The decomposition component y5') barely passes from above. That is, almost no information component corresponding to the transparent base film 67 of the polyimide film insulating material is guided to the CCD device 31 .

Therefore, when information is well extracted from the characteristics of the material forming the semiconductor package in this way, and light is received by the CCD device 31, any inner layer wiring pattern is not reflected, and the uppermost layer wiring pattern can be picked up as an image with high contrast information.

18A shows an image showing an example of the uppermost layer wiring pattern picked up by the sensor camera 30 after the uppermost layer wiring pattern information is obtained by the inspection unit 100 with respect to the multilayer wiring substrate of the semiconductor package, in which There is an inner layer wiring pattern on the substrate through the polyimide insulating layer relative to the uppermost layer wiring pattern. On the other hand, FIG. 18B shows an image showing an example of an uppermost layer wiring pattern also picked up with respect to a multilayer wiring substrate of a semiconductor package on which three layer patterns exist.

As apparent from FIGS. 18A and 18B, even in the case where there is one inner layer wiring pattern, or in the case where there are three layers, only the uppermost layer wiring pattern can be surely extracted brightly. That is, only the uppermost layer wiring pattern can be extracted regardless of the number of inner layers.

Also, FIG. 19A shows an image showing an example of an uppermost wiring pattern obtained by picking up a multilayer wiring substrate of a semiconductor package by an inspection unit via a polyimide insulating layer with respect to an uppermost wiring pattern in which There is a layer of inner layer wiring patterns on the substrate. On the other hand, FIG. 19B shows an image obtained by binary processing the image of FIG. 19A.

As seen from FIG. 19B, when a simple process called binarization is further performed on the image picked up by the inspection unit, the uppermost layer wiring pattern is imaged brighter, while the inner layer pattern and the polyimide insulating film portion Imaged darker, an image in which the wiring pattern of the uppermost layer is clearly distinguished from other parts can be obtained. This binarization has another advantage in that the amount of image data can be reduced and high-speed image processing can be performed.

Also, CAD data (pattern design information) or satisfactory workpieces (workpieces in which wiring patterns are correctly formed) are set in advance as a reference master image, and by comparison with a binarized image, a characteristic extraction method, etc. Part of it is judged as a defect.

Furthermore, the best images for pattern inspection represent a state where pattern edges are clear and without any influence of surface irregularities. The difference in contrast between the wiring pattern part and the polyimide insulating layer part must be clearly divided so that the pattern edge is clear. Therefore, the amount of light with which the workpiece is irradiated must be large, and the workpiece must be bright in order to eliminate the influence of surface irregularities of the wiring pattern.

Fig. 20 shows the situation (curve (d) in the figure) that polarizing beam splitter 70 and polarizing beam splitter 68 are combined in series as shown in Fig. 15C and 16 and as shown in Fig. 15D, polarizing beam splitter 68 and An example of the line distribution in the width direction of the imaging field in the case where the transverse wave polarizing plates 61 are combined so as to improve the polarization efficiency in the light extraction part 58 (curve (e) in the figure).

As seen from the curve (d) in the figure, the incident angle at the end is deviated by 45 degrees with respect to the polarizing beam splitter having an index of incident angle 45 degrees. That is to say, in the case where the polarizing beam splitter 70 is combined with the polarizing beam splitter 68 in series as shown in FIG. 15C , and the condensing lens 12 does not form completely parallel incident light as shown in FIG. As shown in 21B, in the opposite end of polarizing beam splitter 68, the incident angle deviates from 45 degrees (Fig. enters the lower end at an angle of 41 degrees). The opposite side in the width direction of the imaging field is very dark depending on the incident angle, and it must be said that binarization by a single threshold is difficult in this state. As the distance between the condensing lens 12 and the polarizing beam splitter 68 increases, the amount of offset in the opposite end with respect to the applied angle of incidence increases. Therefore, when the polarizing beam splitter 70 is provided between the condensing lens 12 and the polarizing beam splitter 68 , the dependence on the incident angle due to the offset from the applied incident angle in the opposite end portion tends to increase.

On the other hand, when setting the polarizing plate 61 thinner than the polarizing beam splitter 70 instead of the polarizing beam splitter 70 shown in FIG. 15D, as shown in FIGS. The distance between beam splitters 68. Therefore, even if perfectly parallel incident light is not formed by the condensing lens 12, the deviation with respect to the applied incident angle in the opposite end is not so large compared with the use of the polarizing beam splitter 70. Therefore, as seen from the curve (e) in the figure, the effect of the gradation value drop being affected by the shift with respect to the applied incident angle in the opposite end can be improved by using the polarizing plate 61 . FIG. 22A shows the case where completely parallel incident light is formed by the condensing lens 12 . FIG. 22B shows an example of a case where perfectly parallel incident light is not formed by the condensing lens 12 , but the deviation from the applied incident angle is small in the opposite end of the polarizing beam splitter 68 .

It should be noted that even if the polarization filter 34 (polarization plate) is used instead of the quarter-wavelength plate as shown in FIGS. 15A and 15D , only the wiring pattern of the uppermost layer can be clearly imaged.

The best mode for carrying out the invention has been described above with reference to the drawings, but the invention is not limited to this configuration. Any person skilled in the art can think of various modifications and changes within the scope of the inventive technical concept of the patent claims, and it should be understood that these modifications and changes belong to the technical scope of the present invention.

Industrial Applicability

According to the present invention, the influence of the inner layer wiring pattern is optically eliminated from the multilayer wiring substrate of the semiconductor package, and a highly fine image of the uppermost layer wiring pattern can be imaged.

As described above, the inspection apparatus, inspection method, inspection apparatus, and inspection method of wiring patterns capable of automatically inspecting wiring patterns with high reliability can be realized.

Also, when the line sensor technology is applied to an imaging device, an image can be picked up in a short time even for an uppermost layer wiring pattern having a large area, and the configuration can be simplified.

Claims (27)

1. A wiring pattern detection apparatus which optically detects an uppermost layer wiring pattern of a workpiece comprising a multilayer wiring substrate of a semiconductor package having a wiring pattern on at least the front/rear surface of a light-transmitting base film, The equipment includes: light source; parallel light guiding means for guiding light from the light source into substantially parallel light; The first extracting device is used to extract the first linearly polarized light from the light guided by the parallel light guiding device, and the electric field vector direction of the first linearly polarized light is perpendicular to the guiding direction of the light; Circularly polarized light converting means for converting the first linearly polarized light extracted by the first extracting means into circularly polarized light; an irradiation device for irradiating the workpiece with circularly polarized light converted by the circularly polarized light converting device; second extracting means for extracting second linearly polarized light from reflected light obtained by reflecting the circularly polarized light emitted by the illuminating means by the workpiece, the direction of the electric field vector of the second linearly polarized light being the same as that of the first linearly polarized light intersect perpendicularly; selecting means for selecting a wavelength region in which a difference between the amount of reflected light of the uppermost layer wiring pattern and the amount of reflected light of patterns other than the uppermost layer wiring pattern is greater than a predetermined value in the second linearly polarized light; selected wavelength light component guiding means for guiding light components in the wavelength region selected by the selecting means; and An image pickup device for imaging the second linearly polarized light extracted by the second extraction device. 2. A wiring pattern detection apparatus which optically detects an uppermost layer wiring pattern of a workpiece including a multilayer wiring substrate of a semiconductor package having a wiring pattern on at least the front/rear surface of a light-transmitting base film, The equipment includes: light source; parallel light guiding means for directing light from the light source as substantially parallel light; a polarizing beam splitter for extracting first linearly polarized light from light guided by the parallel light guiding means, the direction of the electric field vector of the first linearly polarized light is perpendicular to the light guiding direction, and the polarizing beam splitter is also used for guiding the extracted first linearly polarized light in a light guiding direction and in a direction perpendicular to the electric field vector direction of the first linearly polarized light; a quarter-wavelength plate that converts the first linearly polarized light guided by the polarizing beam splitter into circularly polarized light; an illuminating device for illuminating the workpiece with circularly polarized light converted by the quarter-wave plate; selecting means for selecting a wavelength region in which a difference between the amount of reflected light of the uppermost layer wiring pattern and the amount of reflected light of patterns other than the uppermost layer wiring pattern is greater than a predetermined value in the second linearly polarized light; selected wavelength light component guiding means for guiding light components in the wavelength region selected by the selecting means; and image pickup device, In which the circularly polarized light emitted by the irradiation device is reflected by the workpiece, thereby inverting the direction of rotation, and then transmitted through a quarter-wavelength plate, and the direction of the electric field vector perpendicular to the first linearly polarized light is extracted by a polarizing beam splitter second linearly polarized light, and image the extracted second linearly polarized light by an image pickup device. 3. A wiring pattern inspection apparatus capable of optically inspecting an uppermost layer wiring pattern of a workpiece including a multilayer wiring substrate of a semiconductor package having a wiring pattern on at least the front/rear surface of a light-transmitting base film , the device consists of: light source; parallel light guiding means for guiding light from the light source to be substantially parallel; The first polarizing beam splitter is used to extract the first linearly polarized light from the light guided by the parallel light guiding device, the electric field vector direction of the first linearly polarized light is perpendicular to the light guiding direction; a second polarizing beam splitter for guiding the first linearly polarized light extracted by the first polarizing beam splitter in a direction perpendicular to the light guiding direction and the electric field vector direction of the first linearly polarized light; a quarter-wave plate for converting the first linearly polarized light guided by the second polarizing beam splitter into circularly polarized light; an illuminating device for illuminating the workpiece with circularly polarized light converted by the quarter-wave plate; selecting means for selecting a wavelength region in which a difference between the amount of reflected light of the uppermost layer wiring pattern and the amount of reflected light of patterns other than the uppermost layer wiring pattern is greater than a predetermined value in the second linearly polarized light; selected wavelength light component guiding means for guiding light components in the wavelength region selected by the selecting means; and image pickup device, In which the workpiece reflects the circularly polarized light emitted by the illuminating device, thereby inverting the direction of rotation, and then transmits it through a quarter-wavelength plate, and the second polarizing beam splitter extracts the direction of its electric field vector perpendicular to the first linearly polarized light second linearly polarized light, and image the extracted second linearly polarized light by an image pickup device. 4. A wiring pattern inspection apparatus capable of optically inspecting an uppermost layer wiring pattern of a workpiece including a multilayer wiring substrate of a semiconductor package having a wiring pattern on at least the front/rear surface of a light-transmitting base film , the device consists of: light source; parallel light guiding means for guiding light from the light source to be substantially parallel; a polarizing plate for extracting first linearly polarized light from the light guided by the parallel light guiding means, the direction of the electric field vector of the first linearly polarized light perpendicularly intersects with the light guiding direction; a polarizing beam splitter for guiding the first linearly polarized light extracted by the polarizing plate in a direction perpendicular to the direction of the light guiding direction and the electric field vector direction of the first linearly polarized light; a quarter-wavelength plate that converts the first linearly polarized light guided by the polarizing beam splitter into circularly polarized light; an illuminating device for illuminating the workpiece with circularly polarized light converted by the quarter-wave plate; selecting means for selecting a wavelength region in which a difference between the amount of reflected light of the uppermost layer wiring pattern and the amount of reflected light of patterns other than the uppermost layer wiring pattern is greater than a predetermined value in the second linearly polarized light; selected wavelength light component guiding means for guiding light components in the wavelength region selected by the selecting means; and image pickup device, The workpiece reflects the circularly polarized light emitted by the irradiation device, thereby inverting the direction of rotation, and then transmits it through a quarter-wavelength plate, and the second polarized light whose electric field vector direction is perpendicular to the first linearly polarized light is extracted by a polarizing beam splitter. linearly polarized light, and the extracted second linearly polarized light is imaged by an image pickup device. 5. A wiring pattern detection apparatus which optically detects an uppermost layer wiring pattern of a workpiece including a multilayer wiring substrate of a semiconductor package having a wiring pattern on at least the front/rear surface of a light-transmitting base film, The equipment includes: light source; parallel light guiding means for guiding light from the light source to be substantially parallel; The first extracting means is used to extract the first linearly polarized light from the light guided by the parallel light guiding means, the electric field vector direction of the first linearly polarized light is perpendicular to the light guiding direction; polarized component extracting means for obtaining a predetermined polarized component from the first linearly polarized light extracted by the first extracting means through a polarizing plate having a predetermined angle; irradiating means for irradiating the workpiece with the polarization component obtained by the polarization component extraction means; The second extraction device is used to extract the second linearly polarized light from the reflected light, the electric field vector direction of the second linearly polarized light is perpendicular to the first linearly polarized light, and the reflected light is reflected by the workpiece and emitted by the illuminating device Obtained by the polarization component of selecting means for selecting a wavelength region in which a difference between the amount of reflected light of the uppermost layer wiring pattern and the amount of reflected light of patterns other than the uppermost layer wiring pattern is greater than a predetermined value in the second linearly polarized light; selected wavelength light component guiding means for guiding light components in the wavelength region selected by the selecting means; and An image pickup device for imaging the second linearly polarized light extracted by the second extraction device. 6. A wiring pattern detection apparatus which optically detects an uppermost layer wiring pattern of a workpiece including a multilayer wiring substrate of a semiconductor package having a wiring pattern on at least the front/rear surface of a light-transmitting base film, The equipment includes: light source; parallel light guiding means for guiding light from the light source to be substantially parallel; a polarizing beam splitter for extracting first linearly polarized light from light guided by the parallel light guiding means, the direction of the electric field vector of the first linearly polarized light is perpendicular to the light guiding direction, and the polarizing beam splitter is also used for guiding the extracted first linearly polarized light in the light guiding direction and a direction perpendicular to the electric field vector direction of the first linearly polarized light; a polarization component extracting device for obtaining a predetermined polarization component from the first linearly polarized light guided by the polarizing beam splitter through a polarizing plate having a predetermined angle; irradiating means for irradiating the workpiece with the polarization component obtained by the polarization component extraction means; selecting means for selecting a wavelength region in which a difference between the amount of reflected light of the uppermost layer wiring pattern and the amount of reflected light of patterns other than the uppermost layer wiring pattern is greater than a predetermined value in the second linearly polarized light; selected wavelength light component guiding means for guiding light components in the wavelength region selected by the selecting means; and image pickup device, wherein the second linearly polarized light whose electric field vector direction is perpendicular to the first linearly polarized light is extracted by the polarizing beam splitter from the reflected light obtained by reflecting a polarization component emitted by the illuminating device by the workpiece, And the extracted second linearly polarized light is imaged by an image pickup device. 7. A wiring pattern inspection apparatus capable of optically inspecting an uppermost layer wiring pattern of a workpiece including a multilayer wiring substrate of a semiconductor package having a wiring pattern on at least the front/rear surface of a light-transmitting base film , the device consists of: light source; parallel light guiding means for guiding light from the light source to be substantially parallel; a first polarizing beam splitter for extracting a first linearly polarized light from the light guided by the parallel light guiding means, the direction of the electric field vector of the first linearly polarized light perpendicularly intersects the light guiding direction; a second polarizing beam splitter for guiding the first linearly polarized light extracted by the first polarizing beam splitter in a direction perpendicular to the light guiding direction and the electric field vector direction of the first linearly polarized light; polarization component extracting means for obtaining a predetermined polarization component from the first linearly polarized light guided by the second polarizing beam splitter through a polarizing plate having a predetermined angle; irradiating means for irradiating the workpiece with the polarization component obtained by the polarization component extraction means; selecting means for selecting a wavelength region in which a difference between the amount of reflected light of the uppermost layer wiring pattern and the amount of reflected light of patterns other than the uppermost layer wiring pattern is greater than a predetermined value in the second linearly polarized light; selected wavelength light component guiding means for guiding light components in the wavelength region selected by the selecting means; and image pickup device, wherein the second linearly polarized light whose electric field vector direction is perpendicular to the first linearly polarized light is extracted by the second polarizing beam splitter from the reflected light obtained by reflecting the polarization component emitted by the illuminating device by the workpiece, And the extracted second linearly polarized light is imaged by an image pickup device. 8. A wiring pattern detection apparatus which optically detects an uppermost layer wiring pattern of a workpiece comprising a multilayer wiring substrate of a semiconductor package having a wiring pattern on at least the front/rear surface of a light-transmitting base film, The equipment includes: light source; parallel light guiding means for guiding light from the light source to be substantially parallel; a polarizing plate for extracting first linearly polarized light from the light guided by the parallel light guiding means, the direction of the electric field vector of the first linearly polarized light perpendicularly intersects with the light guiding direction; a polarizing beam splitter for guiding the first linearly polarized light extracted by the polarizing plate in a direction perpendicular to the light guiding direction and the electric field vector direction of the first linearly polarized light; a polarization component extracting device for obtaining a predetermined polarization component from the first linearly polarized light guided by the polarizing beam splitter through a polarizing plate having a predetermined angle; irradiating means for irradiating the workpiece with the polarization component obtained by the polarization component extraction means; selecting means for selecting a wavelength region in which a difference between the amount of reflected light of the uppermost layer wiring pattern and the amount of reflected light of patterns other than the uppermost layer wiring pattern is greater than a predetermined value in the second linearly polarized light; selected wavelength light component guiding means for guiding light components in the wavelength region selected by the selecting means; and image pickup device, Wherein the second linearly polarized light perpendicularly intersecting the first linearly polarized light is extracted from the reflected light obtained by reflecting the polarization component emitted by the illuminating device by the workpiece, and the extracted second linearly polarized light is processed by the image pickup device Polarized light for imaging. 9. The wiring pattern detection apparatus according to any one of claims 1 to 8, Wherein the image pickup device includes a line sensor that continuously images predetermined linear regions in the workpiece and connects the continuously imaged linear regions to each other, thereby imaging a planar region of the workpiece. 10. The wiring pattern detection apparatus according to any one of claims 1 to 8, wherein the parallel light guiding means comprises: a light guide to guide light from a light source; a diffuser plate, which diffuses the light from the light source while keeping the intensity distribution constant; parallelizing means for substantially parallelizing the light diffused by the diffuser plate; and A device for directing parallel light generated by a collimating device. 11. The wiring pattern detection apparatus according to claim 10, comprising: An infrared filter that removes an infrared component from the light from the light source is disposed between the light source and the light guide, or between the light guide and the diffusion plate. 12. The wiring pattern detection apparatus according to any one of claims 1 to 8, further comprising: Cooling unit for cooling parallel light guides. 13. The wiring pattern detecting apparatus according to any one of claims 1 to 8, wherein the selected wavelength light component guiding means comprises one or two or more lenses which will be selected by the selecting means in said Light components in the wavelength region are guided parallel to the image pickup device. 14. The wiring pattern detection apparatus according to any one of claims 1 to 8, wherein the base film is formed of polyimide resin, the wiring pattern is formed of copper, the selection means selects a wavelength region including 550 nm, and the image pickup means comprises CCD. 15. The wiring pattern inspection apparatus according to any one of claims 1 to 4, wherein the workpiece is irradiated with elliptically polarized light instead of circularly polarized light. 16. The wiring pattern inspection apparatus according to any one of claims 1 to 8, wherein the light source comprises a white light source. 17. A wiring pattern inspection apparatus comprising: inspection means for comparing the image picked up by the image pickup means of the wiring pattern inspection apparatus according to any one of claims 1 to 16 with a predetermined satisfactory image A comparison is made, thereby checking whether or not the uppermost layer wiring pattern is satisfactory. 18. A wiring pattern inspection method for optically inspecting an uppermost layer wiring pattern of a workpiece including a multilayer wiring substrate of a semiconductor package having a wiring pattern on at least a front/rear surface of a light-transmitting base film, The method includes: directing light as a substantially parallel parallel light directing step; a first extraction step of extracting a first linearly polarized light whose electric field vector direction perpendicularly intersects the light guiding direction from the light guided in the parallel light guiding step; a circularly polarized light converting step of converting the first linearly polarized light extracted by the first extracting step into circularly polarized light; an irradiating step of irradiating the workpiece with the circularly polarized light converted in the circularly polarized light converting step; A second extraction step of extracting second linearly polarized light whose electric field vector direction perpendicularly intersects the first linearly polarized light from the reflected light which is circularly polarized emitted by the workpiece reflection and emitted in the irradiation step acquired by light; a selection step of selecting a wavelength region in which a difference between an amount of reflected light of the uppermost layer wiring pattern and an amount of reflected light of patterns other than the uppermost layer wiring pattern is greater than a predetermined value in the second linearly polarized light; a selected wavelength light component directing step that directs light components in the wavelength region selected by the selecting step; and an image pickup step of imaging the second linearly polarized light extracted by the second extraction step. 19. A wiring pattern inspection method for optically inspecting an uppermost layer wiring pattern of a workpiece including a multilayer wiring substrate of a semiconductor package having a wiring pattern on at least a front/rear surface of a light-transmitting base film, The method includes: Parallel light guiding means for directing light substantially parallel; a step of extracting, by the polarizing plate, first linearly polarized light from the light guided by the parallel light guiding means, the direction of the electric field vector of the first linearly polarized light perpendicularly intersects the light guiding direction; a step of directing the first linearly polarized light extracted by the polarizing plate in a direction perpendicular to the light guiding direction and the direction of the electric field vector of the first linearly polarized light using a polarizing beam splitter; the step of converting the first linearly polarized light guided by the polarizing beam splitter into circularly polarized light using a quarter wave plate; the step of illuminating the workpiece with circularly polarized light converted by the quarter-wavelength plate; a selection step of selecting a wavelength region in which a difference between an amount of reflected light of the uppermost layer wiring pattern and an amount of reflected light of patterns other than the uppermost layer wiring pattern is greater than a predetermined value in the second linearly polarized light; a selected wavelength light component guiding step of guiding light components in the wavelength region selected by the selecting step; and the steps of, The circularly polarized light emitted to the workpiece is reflected by the workpiece to invert the direction of rotation, after which the polarized light is transmitted through a quarter-wave plate, and the second linearly polarized light is extracted by a polarizing beam splitter so that the extracted second linearly polarized light For imaging, the direction of the electric field vector of the second linearly polarized light perpendicularly intersects with the first linearly polarized light. 20. A wiring pattern inspection method for optically inspecting an uppermost layer wiring pattern of a workpiece including a multilayer wiring substrate of a semiconductor package having a wiring pattern on at least the front/rear surface of a light-transmitting base film, The method includes: directing light as a substantially parallel parallel light directing step; a first extraction step of extracting a first linearly polarized light whose electric field vector direction is perpendicular to the light guiding direction from the light guided by the parallel light guiding step; a polarization component extraction step of obtaining a predetermined polarization component from the first linearly polarized light extracted by the first extraction step through a polarizing plate having a predetermined angle; an irradiation step of irradiating the workpiece with the polarization component obtained by the polarization component extraction step; A second extraction step of extracting second linearly polarized light whose electric field vector direction perpendicularly intersects the first linearly polarized light from reflected light, and the reflected light is a polarization component emitted by the irradiation step by reflection of the workpiece and obtained; a selection step of selecting a wavelength region in which a difference between an amount of reflected light of the uppermost layer wiring pattern and an amount of reflected light of patterns other than the uppermost layer wiring pattern is greater than a predetermined value in the second linearly polarized light; a selected wavelength light component directing step that directs light components in the wavelength region selected by the selecting step; and an image pickup step of imaging the second linearly polarized light extracted by the second extraction step. 21. The wiring pattern detection method according to any one of claims 18 to 20, comprising the steps of: A predetermined linear region in the workpiece is continuously imaged using a line sensor, and the continuously imaged linear regions are connected to each other, thereby imaging a planar region of the workpiece. 22. The wiring pattern detection method according to any one of claims 18 to 20, wherein the parallel light guiding step comprises: a diffusion step that diffuses the light while keeping the intensity distribution constant; a parallelizing step that substantially parallels the light diffused by the diffusing step; and The step of directing parallel light generated by the parallelization step. 23. The wiring pattern inspection method according to claim 22, Wherein the parallel light guiding step further includes an infrared ray removing step of removing infrared components from the light before the diffusing step. 24. The wiring pattern inspection method according to any one of claims 18 to 20, wherein the base film is formed of polyimide resin, the wiring pattern is formed of copper, the selecting step selects a wavelength region including 550 nm, and the image pickup step Images are picked up by a CCD. 25. The wiring pattern inspection method according to claim 18 or 19, comprising the step of irradiating the workpiece with elliptically polarized light instead of circularly polarized light. 26. The wiring pattern inspection method according to any one of claims 18 to 20, wherein the light source comprises a white light source. 27. A wiring pattern inspection method comprising the step of comparing an image picked up by the wiring pattern inspection method according to any one of claims 18 to 26 with a predetermined satisfactory image to inspect the Whether the uppermost layer wiring pattern is satisfactory.

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