CN105277574B - Multi-exposure image mixing detection method applying repeated exposure - Google Patents

Abstract

The invention discloses a detection method using multiple exposure image mixing using repeated exposure, including: step S100: setting multiple light sources with at least one of different wavelength bands and illumination angles in a first configuration The respective exposure time values of the devices; Step S200: Perform repeated exposures to sequentially turn on the corresponding exposure time values of these light source devices and then turn them off, so that these light source devices sequentially illuminate the circuit substrate to be tested and the image capture device generates these The detection image mixed within the exposure time value; and step S300: output the detection image for analysis and inspection. In this way, the present invention records the image information mixed under different illumination lights in one detection image, which can eliminate the need for each light source device to capture images separately, and obtain multiple images at the same time, which can simplify the process. And effectively shorten the detection time.

Description

Detection method of multi-exposure image blending using repeated exposure

technical field

The invention relates to an optical detection method for a detection circuit, in particular to a detection method using repeated exposure and multi-exposure image mixing.

Background technique

Optical identification systems, such as Automated Optical Inspection (AOI) and Automatic Final Inspection (AFI), are now widely used in the inspection process of circuit board assembly production lines in the electronics industry. It is used to replace the previous manual visual inspection operation. It uses image technology to compare whether the object under test is different from the standard image to judge whether the object under test meets the standard.

Therefore, the detection of the optical recognition system on the circuit plays a pivotal role, which also makes the detection cost in the manufacturing cost of electronic products depend on the quality and speed of the optical recognition system. In addition to the basic requirements of accuracy, the optical identification system is more important to be able to achieve the accurate inspection of the required circuit specifications in the shortest time. Therefore, even if the optical identification system has high-precision screening capabilities, once the detection speed cannot be effectively improved, the detection cost will increase, thereby affecting the overall production volume.

In the prior art, such as the U.S. Publication No. US7355692 Patent of Invention, it discloses an optical detection program set up in two detection stations, through the analysis results of the image (reflected light image) captured by the first station, and then in the second station for The analysis result captures another image (fluorescence image), so that the circuit defect analysis is performed based on the two images captured under two different workstations. This detection method not only has a complicated detection process (the first workstation and the second workstation must be operated separately), but also greatly increases the time required for detection (because two images are captured at different workstations at different time intervals), so The configuration and method will produce the shortcoming that the production volume cannot be effectively improved due to the inability to increase the detection speed.

Contents of the invention

An object of the present invention is to simplify the process of optical inspection and shorten the time required for inspection.

Another object of the present invention is to provide a detection method that can be used for various configuration settings of the detection machine.

In order to achieve the above and other purposes, the present invention proposes a detection method for multiple exposure image blending using repeated exposure, including: Step S100: setting at least one of the two different wavelength bands and irradiation angles under the first configuration The respective exposure time values of one of the plurality of light source devices, these exposure time values constitute the total exposure time; step S200: perform repeated exposures and sequentially enable these light source devices to turn on the corresponding exposure time values and then turn off, so that these light source devices Sequentially irradiate the circuit substrate to be tested, and the image capture device generates a detection image mixed with light rays of at least one of different wavelength bands and irradiation angles within these exposure time values; and step S300: output the detection images for analysis.

In one embodiment of the present invention, step S210 is also included after step S200: determine whether there are light source devices with other configurations, if “No”, enter step S300, and if “Yes”, enter step S220 to perform another set of The setting of the respective exposure time values of the plurality of light source devices in the state returns to step S200 to generate another detection image for analysis and inspection.

In an embodiment of the present invention, the light source device of the first configuration includes a visible light band light emitting device and an invisible light band light emitting device.

In an embodiment of the present invention, under the judgment of whether the metal circuit on the circuit substrate to be tested is disconnected, the light source device of the first configuration is a visible light band light emitting device and an ultraviolet light band light emitting device, and the visible light band light emitting device The ratio of the exposure time value to the total exposure time is smaller than the ratio of the exposure time value of the ultraviolet band light-emitting device to the total exposure time. Further, the exposure time value of the visible light band light emitting device accounts for 30% of the total exposure time, and the exposure time value of the ultraviolet light band light emitting device accounts for 70% of the total exposure time.

In one embodiment of the present invention, under the judgment of whether the metal circuit on the circuit substrate to be tested protrudes, the light source device of the first configuration is a visible light band light emitting device and an ultraviolet light band light emitting device, and the visible light band emits light The ratio of the exposure time value of the device to the total exposure time is equal to the ratio of the exposure time value of the ultraviolet band light-emitting device to the total exposure time.

In one embodiment of the present invention, under the judgment of whether the green paint surface on the circuit substrate to be tested is defective, the light source device of the first configuration is a side light emitting device and a front light emitting device, and the side light emitting device The ratio of the exposure time value to the total exposure time is equal to the ratio of the exposure time value of the positive light emitting device to the total exposure time.

In this way, the present invention uses the camera device to repeatedly expose the circuit substrate to be tested, so that the images presented by the circuit substrate to be tested under different irradiation lights are recorded together on one detection image, so that subsequent analysis and inspection can be directly performed by The detection image can quickly determine the defects of the circuit substrate to be tested without the need to compare images and search and locate defects on multiple images, which can simplify the process of optical inspection and effectively shorten the time required for inspection .

Description of drawings

FIG. 1 is a schematic configuration diagram of a detection system in an embodiment of the present invention.

Fig. 2 is a flowchart of a detection method in an embodiment of the present invention.

3a, 3b, and 3c are schematic diagrams of images showing whether the metal lines are disconnected in one-side scanning embodiment of the present invention.

4 a , 4 b , and 4 c are schematic diagrams of images showing whether the metal lines protrude in the one-side scanning embodiment of the present invention.

5a, 5b, and 5c are schematic diagrams of images showing whether there are defects on the green paint surface of the circuit board in the embodiment of the one-line scanning of the present invention.

Main component reference signs:

100 detection platform

110 circuit substrate to be tested

210 Light source unit for first configuration

220 Light source units of other configurations

310 image capture device

330 computing mainframe

Steps from S100 to S300

Detailed ways

For fully understanding purpose of the present invention, feature and technical effect, hereby by following specific embodiment, in conjunction with accompanying drawing, the present invention is described in detail, as follows:

First, please refer to FIG. 1 , which is a schematic configuration diagram of a detection system in an embodiment of the present invention. The optical detection system includes: a plurality of light source devices 210 , 220 , a detection platform 100 , a circuit substrate to be tested 110 , an image capture device 310 and a computing host 330 . The number of groups of these light source devices is set correspondingly according to actual needs. The circuit substrate 110 to be tested can be a flexible circuit board, a rigid circuit board or other boards with circuit structures. The image capture device 310 can be adjusted correspondingly according to the best viewing angle, and it is not limited to be directly above the circuit substrate 110 to be tested as shown in FIG. 1 . The computing host 330 is used to correspondingly control the operation and on/off time of the light source devices 210 and 220 according to the settings.

In optical detection, through the light source irradiation of the light source device 210 of the first configuration or the light source device 220 of other configurations, reflected light, scattered light or excitation light can be generated on the circuit substrate 110 to be tested. Each light source operating in the inspection items required by the circuit substrate 110 is recorded in the same image, and the operation method flow will be described as follows.

Please refer to FIG. 2 , which is a flowchart of a detection method in an embodiment of the present invention. The detection method for multi-exposure image mixing using repeated exposure of the present invention includes:

Step S100: setting the respective exposure time values of the plurality of light source devices having at least one of different wavelength bands, different wavelength bands and irradiation angles under the first configuration, and these exposure time values constitute the total exposure time;

Step S200: Perform repeated exposures to sequentially turn on the corresponding exposure time values of these light source devices and then turn them off, so that these light source devices sequentially irradiate onto the circuit substrate to be tested and the image capture device generates images of different wavelengths within these exposure time values. A detection image mixed with light rays of at least one of the segment and the irradiation angle; and

Step S300: Output the detection image for analysis and inspection.

The above-mentioned steps are the process of one light source configuration, and when the detection system has multiple configurations of light source configurations, the above-mentioned steps and process will be carried out after switching to the next light source configuration. The illumination of different light source configurations in the present invention refers to the corresponding configuration of the light source device for the type of circuit defect to be detected, for example: some defects need to be illuminated with vertical light, while others need to be illuminated with oblique angle side light , so it can be divided into two lighting configurations from the perspective of lighting. Moreover, some defects need to be illuminated with special wavelengths, such as: generally using ultraviolet light to stimulate fluorescence, using red light to enhance the reflection of metal copper surfaces, Green light is used to enhance the reflection of green paint, and near-infrared light is used to enhance line detection under green paint, etc., so the lighting wavelength can be divided into two or more lighting configurations. Therefore, for the different light source configurations described in the present invention, the defect analysis does not need to use different images captured between different light source configurations, and the present invention can complete the detection of the corresponding defect types under a single illumination configuration , the switch between different configurations provided by the present invention is used for detecting different defects.

As shown in FIG. 3 a , FIG. 3 b , and FIG. 3 c , they are schematic diagrams of the image of whether the metal circuit is disconnected in the one-side scanning embodiment of the present invention. Figure 3a is the result of using visible light in the lighting configuration sheet; Figure 3b is the result of using ultraviolet light in the lighting configuration sheet; Figure 3c is the result of using visible light and ultraviolet light in the lighting configuration based on the repeated exposure of the present invention, only two The ratio of the light source is different. It is worth mentioning that FIG. 3a and FIG. 3b can also be implemented by using the repeated exposure lighting configuration of the present invention. For example, FIG. 3a can be modified to use a larger proportion of visible light (99%) and a smaller proportion of ultraviolet light ( 1%); Figure 3b can be modified to use a combination of a smaller proportion of visible light (1%) and a greater proportion of ultraviolet light (99%). The above description is for the multi-band method, and if it is described with the subsequent FIG. 5 of the present invention, it is for the multi-angle method. Accordingly, as long as multiple bands and multiple angles are combined, a single image with multiple information can be obtained under scanning in the same time interval for detection and judgment.

Step S210 is also included after step S200: determine whether there are light source devices with other configurations, if "No", enter step S300, and if "Yes", enter step S220 to perform another configuration with different wavelength bands The setting of the respective exposure time values of the plurality of light source devices returns to step S200 to generate another detection image for analysis and inspection.

Wherein, the light source device of the first configuration includes a visible light band light emitting device and an invisible light band light emitting device. Please refer to the accompanying drawings of the present invention. In FIG. 3a, the gray-scale image of the suspected metal line disconnection defect (circled by the dotted line) seen by irradiating the circuit substrate to be tested with visible light alone, and the invisible light of ultraviolet light in FIG. 3b The gray-scale image of the metal line disconnection defect (dotted circle) seen by irradiating the circuit substrate to be tested, in the past, it was necessary to obtain two images separately, and then the operator judged whether it was a defect. As shown in Figure 3c, it can be directly seen from the figure that the dotted circle "does not have" the defect that the metal line is disconnected, because the substrate part of the non-metal line will absorb ultraviolet light and generate excitation light, so The image of this part will be brightened, and under the operation of the present invention, because the gray value of the suspected metal line disconnection defect in Figure 3c is not similar to the gray value of the substrate, it can be obtained by a single detection image. It can be directly judged that the dotted circle "does not have" the defect that the metal line is disconnected.

Please refer to Figure 3a, Figure 3b, and Figure 3c. It is worth mentioning that, based on the judgment of whether the above-mentioned metal line is disconnected, under the preferred configuration, except that the light source device of the first configuration is a visible light band light-emitting device and an ultraviolet light Further, the ratio of the exposure time value of the visible light band light emitting device to the total exposure time is smaller than the ratio of the exposure time value of the ultraviolet light band light emitting device to the total exposure time. For example, the exposure time value of the visible light band light emitting device accounts for 30% of the total exposure time, and the exposure time value of the ultraviolet light band light emitting device accounts for 70% of the total exposure time. However, the present invention is not limited thereto, and it can be used under the condition that the ratio of the exposure time value of the visible light-band light-emitting device to the total exposure time is smaller than the ratio of the exposure time value of the ultraviolet-band light-emitting device to the total exposure time. It has a better display effect.

Next, please refer to FIG. 4 a , FIG. 4 b , and FIG. 4 c , which are schematic diagrams of images showing whether the metal circuit has protrusions in the one-side scanning embodiment of the present invention. In Figure 4a, the gray-scale image of suspected protruding defects (arrows) on the metal circuit board is seen when the circuit board under test is irradiated with visible light alone, and it is seen in Figure 4b when the circuit board under test is irradiated with invisible light such as ultraviolet light In the grayscale image with a protruding metal line defect (at the arrow), in the past, two images had to be obtained separately and then the operator judged whether it was a defect. The image obtained after the operation method of the present invention is shown in Figure 4c. It can be directly seen from the accompanying drawings that the arrows "do not have" the defect of the metal line protruding (it appears concave), because the substrate part of the non-metal line will absorb ultraviolet light and generate excitation light, so the Part of the image becomes brighter, and under the operation of the present invention, because the gray value of the suspected metal line protruding defect in Figure 4c is not similar to the gray value of the metal, it can be directly judged from a single detection image The arrow "does not have" the defect of protruding metal lines.

Please refer to Figure 4a, Figure 4b, and Figure 4c. It is worth mentioning that, based on the judgment of whether the above-mentioned metal circuit has protrusions, under the preferred configuration, except that the light source device of the first configuration is a visible light band light-emitting device and an ultraviolet Light-band light-emitting device, further, the ratio of the exposure time value of the visible light-band light-emitting device to the total exposure time is equal to the ratio of the exposure time value of the ultraviolet-band light-emitting device to the total exposure time. For example, the exposure time value of the visible light band light emitting device accounts for 50% of the total exposure time, and the exposure time value of the ultraviolet light band light emitting device accounts for 50% of the total exposure time, so as to achieve a better display effect.

Next, please refer to FIG. 5 a , FIG. 5 b , and FIG. 5 c , which are schematic diagrams of images showing whether there are defects on the green paint surface of the circuit board in the first-line scanning embodiment of the present invention. The difference in operation between line scan and area scan is that the scanned image is clearer and more accurate, but the current scan needs to move the entire optical system to perform line scan inspection one by one.

In Figure 5a, the gray-scale image of the suspected circuit board defect (arrow) seen on the green paint surface of the circuit board to be tested is irradiated with white side light visible light only, and in Figure 5b only irradiated with white positive light (normal incident) visible light The grayscale image of the circuit board defect (arrow) seen on the green paint surface of the circuit board to be tested. In the past, it was necessary to obtain two images separately, and then the operator judged whether it was a defect. The image obtained after the operation method of the present invention is shown in Figure 5c. From the attached drawing, it can be directly seen that the arrow "has" the green color of the circuit board. defects on the paint surface, and the contrast of the overall image is also better than the image seen by irradiating the circuit substrate to be tested with white side light (as shown in Figure 5a). The gray value of the defect is not similar to the gray value of the normal green paint surface, so it can be directly judged that the arrow "has" the defect of the green paint surface of the circuit board from a single inspection image.

Please refer to Figure 5a, Figure 5b, and Figure 5c. It is worth mentioning that, based on the judgment of whether the above-mentioned circuit board has defects, under the preferred configuration, except that the light source device of the first configuration is a side light emitting device and a front light emitting device Further, the ratio of the exposure time value of the side light emitting device to the total exposure time is equal to the ratio of the exposure time value of the front light emitting device to the total exposure time. For example, the exposure time value of the side light emitting device accounts for 50% of the total exposure time, and the exposure time value of the front light emitting device accounts for 50% of the total exposure time, so as to achieve a better display effect . In other words, Fig. 5a shows that under the condition of no repeated exposure, after only irradiating with white side light (incidence at about 45 degrees), although it is easier to detect defects for the metal in the window area, but for the green paint surface However, the scratches cannot be clearly detected; Figure 5b also shows that under the condition of no repeated exposure, after only using white positive light (~90 degrees) to irradiate, although the contrast for the metal in the window area is not as shown in Figure 5a It is good, but the scratches on the surface of the green paint can be clearly detected; Figure 5c shows that under the repeated exposure conditions of the present invention, as long as the ratio parameters of the front light and the side light are adjusted, the same detection can be performed. Acquire a single image within the time interval. In this image, although the contrast is not as good as in Figure 5a for the metal in the window opening area, it is better than Figure 5b; for the scratches on the green paint surface, the contrast is not as good as Figure 5b, but better than Figure 5a, This is one of the advantages of the repeated exposure technique of the present invention.

To sum up the above, the present invention uses the camera device to repeatedly expose the circuit substrate to be tested, so that the images presented by the circuit substrate to be tested under different irradiation lights are recorded together on one detection image, which can simplify the process of optical detection and effectively shorten the detection time. The time required for detection.

The present invention has been disclosed above with preferred embodiments, but those skilled in the art should understand that the embodiments are only for describing the present invention, and should not be construed as limiting the scope of the present invention. It should be noted that all changes and substitutions equivalent to this embodiment should be considered within the scope of the present invention. Therefore, the protection scope of the present invention should be determined by the contents defined in the claims.

Claims (7)

1. the detection method that a kind of more exposed images using repeated exposure mix, it is characterised in that include：

Step S100：Set tool different wave length section under the first configuration and irradiating angle is at least one of multiple both this The respective exposure time values of light supply apparatus, these exposure time values composition total exposure time；

Step S200：Carry out repeated exposure and sequentially make these light supply apparatuses open corresponding to close after exposure time values so that These light supply apparatuses are sequentially exposed on circuit under test substrate and produced by image capturing device in these exposure time values by not Detection image mixed by least one of light of co-wavelength section and irradiating angle both this；And

Step S300：The detection image is exported so that analysis checks, and the circuit under test base is directly judged by the detection image The defects of plate.

2. detection method as claimed in claim 1, it is characterised in that step S210 is also included after step S200：Judge Whether there is the light supply apparatus of other configurations, step S300 is entered when "No", enter step S220 when "Yes" and carry out another The setting of the respective exposure time values of multiple light sources device under configuration returns step S200 and supplied with producing another detection image Analysis checks.

3. detection method as claimed in claim 1, it is characterised in that the light supply apparatus of first configuration includes visible light wave range Light-emitting device and black light wave band light-emitting device.

4. detection method as claimed in claim 1, it is characterised in that whether the metallic circuit on the circuit under test substrate breaks Under the judgement opened, the light supply apparatus of first configuration is visible light wave range light-emitting device and ultraviolet light wave band light-emitting device, and this can See that the exposure time values of optical band light-emitting device account for exposure of the ratio less than the ultraviolet light wave band light-emitting device of the total exposure time Light time value accounts for the ratio of the total exposure time.

5. detection method as claimed in claim 4, it is characterised in that the exposure time values of the visible light wave range light-emitting device account for The ratio of the total exposure time is 30%, and the exposure time values of the ultraviolet light wave band light-emitting device account for the ratio of the total exposure time For 70%.

6. detection method as claimed in claim 1, it is characterised in that whether the metallic circuit on the circuit under test substrate has Under the judgement of protrusion, the light supply apparatus of first configuration is visible light wave range light-emitting device and ultraviolet light wave band light-emitting device, is somebody's turn to do The ratio that the exposure time values of visible light wave range light-emitting device account for the total exposure time is equal to the ultraviolet light wave band light-emitting device Exposure time values account for the ratio of the total exposure time.

7. detection method as claimed in claim 1, it is characterised in that whether the green paint surface on the circuit under test substrate has Under the judgement of defect, the light supply apparatus of first configuration is side-view light emitting device and positive light light-emitting device, the side-view light emitting device Exposure time values account for the total exposure time ratio be equal to the positive light light-emitting device exposure time values account for the total exposure time Ratio.