JPH07122568B2 - Mounted component inspection device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a mounted component inspection for automatically inspecting a mounted state of electronic components mounted on a printed board, a hybrid IC, etc. by using a principle of optical cutting method and triangulation. Regarding the device.

2. Description of the Related Art Conventionally, as a mounted component inspection device for automatically inspecting a mounted state of an electronic component mounted on a printed board, a hybrid IC or the like, a configuration using an optical cutting method is known. Less than,
The conventional mounted component inspection device will be described with reference to the drawings.

A slit-shaped light beam 1 ₁ is scanned while irradiating perpendicularly to the non-examination on the object that implements the component Q on the printed board P as shown in FIG. 4, detects the reflected light 1 ₂ with one licensor 51 Then, combine the obtained two-dimensional light section images and
The three-dimensional shape of is picked up and compared with a reference pattern to inspect the mounting state of the component Q.

However, when the three-dimensional shape of the component Q is measured from one direction by using one licenser 51 in this way, it is not possible to detect the shaded portion of the component Q.

Therefore, as another example of the conventional mounted component inspection device,
Light beam 1 ₁ reflected light 1 ₂ obtained from the object to be inspected by irradiation of, as shown in FIG, 1 ₃ two line sensors 52 and 53
In order to eliminate the undetectable part of the component Q due to the above-mentioned shadow, the two types of data relating to the height and the luminance obtained by the detection are detected from two directions symmetrical with respect to the beam surface. It has been proposed (see JP-A-63-128242). In this mounted component inspection apparatus, height data is synthesized based on luminance data as a means for the above synthesis.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in the above-described conventional mounted component inspection device, the response speed is slow because the line sensor detects the reflected light from the inspection object. 2 regarding height and brightness
Upon synthesizing the kind of data, because it synthesizes the height data on the basis of luminance data, as shown in FIG. 5, the light beam 1 ₁ is highly reflective irradiated vertically on the object to be tested When a portion, for example, the metal portion such as the solder portion Q ₁ where the component Q is attached to the print substrate P is reflected and another portion shines, the height measured by the line sensor 52 is equal to the true height H. H ₁ , the height measured by the line sensor 53 is
There was a problem that it became H ₂ and erroneous data was synthesized as it was.

The present invention solves such a conventional problem, and it is possible to eliminate the influence of the shadow without deleting the effective data of the portion where the reflected light is small, and moreover, the light beam reflects the metal portion or the like. The reliability of the inspection can be improved by eliminating the influence of reflection on the high-ratio portion.
Another object is to provide a mounted component inspection device capable of accelerating detection and accelerating component inspection. Also, erroneous data is deleted and only reliable data is correctly synthesized. Therefore, it is an object of the present invention to provide a mounted component inspection device capable of improving the reliability of inspection.

Means for Solving the Problems In order to achieve the above-mentioned object, the present invention provides a light irradiating means for scanning while vertically irradiating a light beam on an object to be inspected on which a component is mounted, and a light irradiating means for irradiating the light beam. Reflected light obtained from the object to be inspected is detected as a two-dimensional optical image from two directions that are symmetrical with respect to the main scanning direction of the light beam, and luminance data corresponding to the reflectance of the object to be inspected and the object to be inspected. Whether the two PSDs that output the height data according to the height and the two types of luminance data that are output from these PSDs are within the predetermined range that defines the minimum value and the maximum value, respectively. A first comparing means for comparing, a second comparing means for comparing the difference between the two types of brightness data and a predetermined value of the brightness difference, and a difference between the two types of height data output from the PSD and a high value. Comparing the predetermined difference of 3 comparing means, averaging means for obtaining an average value of the two types of height data, and either of the two types of height data depending on the comparison result of the first, second and third comparing means. Alternatively, it is provided with a selection means for selecting the average value as the combined height data.

Operation The present invention has the following effects due to the above-mentioned configuration.

The reflected light obtained from the object to be inspected by the irradiation of the light beam is detected from two directions which are symmetrical with respect to the main scanning direction of the light beam, and the synthesizing means detects two kinds of height data based on the two brightness data. In the composite, that is, in the part without shadow, the value obtained by averaging two types of height data is selected as the composite height data, and in the shadow part, the non-shadow (higher brightness) height data is selected as the composite height data. Since the selection is made, even if irregular noise occurs in one of the two types of data, it is averaged with the other to form the synthetic data, so that it is possible to reduce the influence of the noise as a whole. , The influence of the shadow can be eliminated, highly reliable data can be obtained, and the PSD is used as the means for detecting the reflected light, the response speed becomes faster.

Alternatively, the synthesizing means compares the difference between the two types of luminance data with a predetermined value, and if the difference in luminance data is larger, the height data corresponding to the larger luminance data is selected as the synthesized height data, 2 if the difference in luminance data is smaller
By selecting the average value of the height data of various types as the composite height data, it is possible to eliminate the influence of the shadow, and of course not to delete the data of the part with little reflected light, so that the reliable data Can be obtained.

Alternatively, the synthesizing means compares the two types of brightness data in addition to the two types of brightness data, and if the absolute value of the difference is larger than a predetermined value, deletes the data and determines that the absolute value of the difference is smaller than the predetermined value. For example, by selecting the average value of the two types of height data as the combined height data, it is possible to eliminate the influence of erroneous data, that is, the ghost effect caused by the light beam hitting the highly reflective part of the component, and reliability can be eliminated. It is possible to obtain high data.

Examples Hereinafter, examples of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view showing an optical system (light irradiation means and light detection means) of a mounted component inspection apparatus according to an embodiment of the present invention.

In the figure, laser light output from the He-Ne laser 1
1 ₁ is bent by the mirror 2 is scanned in the Z-direction by the polygon mirror 4. This light beam 1 ₁
It is placed on a stage 6 that moves in the X direction via an f · θ lens 5, and is vertically irradiated onto a board R on which a component Q is mounted on a printed board P. Therefore, the substrate R is scanned by the light beam ₁₁ in the Z and X directions.

The light beam 1 ₁ of the reflected light 1 _2, 1 ₃ reflecting mirrors 7 and 8 from two symmetrical directions with respect to the scanning direction Y axis the light beam 1 _1,
Two PS through the polygon mirror 4 and the imaging lenses 9 and 10.
D (Position Sensitive Detectors) 11,
Each is detected at 12.

Image obtained by the above PSD11,12, for example, as shown in Figure 2, which is an object to be inspected which reflects the light beam 1 ₁ part Q, the shift a corresponding to each height H of the printed board P It is possible to obtain a multi-gradation gray-scale image having a brightness corresponding to the reflectance of the inspection target, as well as an obtained image.

The stage 6, polygon mirror 4 and PSD1
1 and 12 are appropriately synchronized with each other so that two types of images can be sequentially obtained over the entire surface of the printed board P on which the component Q to be inspected is mounted.

Next, a synthesizing circuit that is a means for creating a synthetic height H ₀ from two types of height data H ₁ and H ₂ and luminance data I ₁ and I ₂ obtained from the two PSDs 11 and 12 will be described.

As shown in FIG. 3, the synthesis circuit is composed of four comparison circuits 15,
It is composed of 16, 17, and 18, two subtraction circuits 13 and 14, one averaging circuit 19, and one selection circuit 20. The comparison circuits 15 and 16 respectively compare inputs A, B, and C of predetermined maximum brightness (Imax), predetermined minimum brightness (Imin), and brightness data I ₁ obtained by detection of the PSD 11, and A>C> If it is B, the output D is set to “1”, and if A ≦ C or B ≧ C, the output D is set to “0”. The subtraction circuit 13 subtracts the input A of the brightness data I ₂ obtained by the detection of the PSD 12 from the input B of the brightness data I ₁ obtained by the detection of the PSD 11, and sets this subtraction value (BA) as the output C, The subtraction circuit 14 has a PSD 11
Input of height data H ₁ obtained by detection of A to PSD12
Subtract the input B of the height data H ₂ obtained by the detection of
This subtracted value (AB) is used as the output C. The comparison circuit 18 is
The input A, that is, the absolute value of the output C of the subtraction circuit 14 and the input B of a predetermined value (Hdiff) of the height difference are compared. If | A | <B, the output C is set to "1", and | A If | ≧ B, the output C is set to “0”. The averaging circuit 19 is a circuit that averages the inputs A and B of the height data H ₁ and H ₂ and outputs the average value (A + B) / 2 as the output C. The comparison circuit 17 compares the input A, that is, the output C of the subtraction circuit 13 with the input B of the predetermined value (Idiff) of the brightness difference, and if A> B, sets the output C to “0”,
If A <−B, the output C is set to “1”, and −B ≦ A ≦ B
If so, the output C is set to "2". The selection circuit 20 has inputs A, B, C, D, E, F, G, that is, the output D of the comparison circuit 15, the output D of the comparison circuit 16, the output C of the comparison circuit 17, the output C of the comparison circuit 18, and the average. Output C of circuit 19, height data H ₁ ,
Height data H ₂ and output H are set as shown in the table below.

In the above synthesizing circuit, when neither of the brightness data I ₁ and I ₂ is outside the predetermined value range, that is, between Imax and Imin, the output D of the comparison circuits 15 and 16 (the input A of the selection circuit 20,
Both of B) become "0", and the selection circuit 20 deletes the data. Also, only one of the luminance data I ₁ has a predetermined value, Imax.
When it is within the range of Imin, the output D of the comparison circuit 15 (input A of the selection circuit 20) becomes "1", and the output of the comparison circuit 16 (input B of the selection circuit 20) becomes "0". circuit
At 20, the input F having the height H ₁ corresponding to the brightness data I ₁ is selected and output as the combined height data. On the contrary,
When only the other luminance data I ₂ is within the range of the predetermined values Imax and Imin, the output D of the comparison circuit 15 (the input A of the selection circuit 20) becomes “0” and the output D of the comparison circuit 16 (the selection circuit 20).
Input B) becomes “1” and the selection circuit 20 outputs the brightness data I ₂
Input G of the height data H ₂ corresponding to is selected and output as combined height data. In addition, the brightness data I ₁ and I ₂ are both within a predetermined value, Imax and Imin,
When the difference between I ₁ and I ₂ is larger than the predetermined value Idiff of the brightness difference, the outputs D of the comparison circuits 15 and 16 (the inputs A and B of the selection circuit 20).
Are both "1", and the output C of the comparison circuit 17 (selection circuit 20
Input C) becomes “0” (when the brightness data I ₁ is large) or “1” (when the brightness data I ₂ is large), and the height data H ₁ of the larger brightness data in the selection circuit 20, or Input F or G of H ₂ is selected and output as combined height data. Further, the luminance data I ₁ and I ₂ are both within a predetermined value, Imax and Imin, and the luminance data I ₁ and
When the difference of I ₂ is smaller than the predetermined value Idiff of the brightness difference, the output C of the comparison circuit 17 (input C of the selection circuit 20) becomes “2”, and the absolute value of the difference between the height data H ₁ and H ₂ is predetermined. If it is smaller than the specific height difference Hdiff of, the input D of the output C (selection circuit 20) of the comparison circuit 18 becomes “1”, and the height data H ₁ which is the output C of the averaging circuit 19 in the selection circuit 20. And the average value of H ₂ are selected and output as combined height data, and height data H ₁ and
If the absolute value of the difference of H ₂ is larger than or equal to the predetermined specific height difference Hdiff, the output C of the comparison circuit 18 (the input D of the selection circuit 20 becomes “0”, and the data is selected by the selection circuit 20). To be deleted.

Therefore, two types of height data H ₁ ,
A value obtained by averaging H ₂ is selected as the composite height data H ₀ , and in the shaded area, the height data of the non-shadowed area (the one with higher brightness)
H _1, or since H ₂ is selected as the composite height data H _0, the synthesis height data H ₀ not only no influence by shade, the influence of noise, the tilt effect of the polygon mirror 4 Get smaller.

When averaging the two types of height data H ₁ and H ₂ as described above to select the combined height data H ₀ , the following three examples can be selected in the present invention. That is, if the two types of luminance data I ₁ and I ₂ are both within a predetermined value, Imax and Imin, the two types of height data H ₁ and H ₂ are averaged and the combined height data H ₀ is averaged. Can be However, in the above example, in order to eliminate the influence of the shadow, when Imin is set to be considerably high, there is a possibility that the data may be deleted up to the part of the component Q where the reflected light is small. Therefore, Imin is set low, and the difference between the two types of brightness data I ₁ and I ₂ is compared with a predetermined value Idiff of the brightness difference. If the difference between the brightness data I ₁ and I ₂ is greater, The height data H ₁ or H ₂ corresponding to the larger one is selected as the combined height data H ₀ , and if the difference between the brightness data I ₁ and I ₂ is smaller, two types of height data H ₁ and H 2 By selecting the average value of ₂ as the combined height data H ₀ , it is possible not to delete the data of the portion where the reflected light is small and to eliminate the influence of the shadow. Further, as described in the above embodiment, in addition to the above two types of luminance data I ₁ and I ₂ , two types of height data H ₁ and H ₂ are compared,
If the absolute value of the difference is larger than the predetermined value Hdiff of the height difference, the data is deleted, and the absolute value of the difference is the predetermined value Hdif of the height difference.
If it is smaller than f, by selecting the average value of the two types of height data H ₁ and H ₂ as the combined height data H ₀ , for example,
The defective data of the ghost caused by the cause as shown in FIG. 5 can be deleted.

Then, with these synthetic height data H ₀ and the luminance data on the movement of the X-axis direction of the rotation by the light beam 1 ₁ in the Z-axis direction of the scan and the mounting substrate R of the polygon mirror 4, by sequentially it takes, known Get 3D shape data by
The mounting state of the component Q can be inspected based on this shape data.

The light irradiation means in the present invention is not limited to the configuration including the He-He laser 1 and the f.theta. Lens 5 shown in FIG. It may have any configuration as long as it is provided. Also,
In the above embodiment, the component Q to be inspected is the printed board P.
Although the case of using the board R mounted in the above is explained, the present invention can be applied to any object on which an electronic component is mounted.

As described above, according to the present invention, the reflected light obtained from the object to be inspected by the irradiation of the light beam is detected from two directions symmetrical with respect to the main scanning direction of the light beam, and the combining means Two kinds of height data are combined based on one brightness data, that is, the average value of the two kinds of height data is selected as the combined height data in the non-shadowed part, and the non-shadowed part (the brightness Since the height data of the (larger one) is selected as the combined height data, even if irregular noise occurs in one of the two types of data, it is averaged with the other to become the combined data, Looking at it, the influence of noise can be reduced, the influence of shadows can be eliminated, highly reliable data can be obtained, and PSD is used as a means of detecting reflected light. The answer speed becomes faster. Therefore, it is possible to improve reliability and speed of component inspection.

Alternatively, the synthesizing means compares the difference between the two types of luminance data with a predetermined value, and if the difference in luminance data is larger, the height data corresponding to the larger luminance data is selected as the synthesized height data, 2 if the difference in luminance data is smaller
By selecting the average value of the height data of various types as the composite height data, it is possible to eliminate the influence of the shadow, and of course not to delete the data of the part with little reflected light, so that the reliable data Can be obtained. Therefore, the reliability of component inspection can be further improved.

Alternatively, the synthesizing means compares the two types of brightness data in addition to the two types of brightness data, and if the absolute value of the difference is larger than a predetermined value, deletes the data and determines that the absolute value of the difference is smaller than the predetermined value. For example, by selecting the average value of the two types of height data as the combined height data, it is possible to eliminate the influence of erroneous data, that is, the ghost effect caused by the light beam hitting the highly reflective part of the component, and reliability can be eliminated. It is possible to obtain high data. Therefore, the reliability of component inspection can be further improved.

[Brief description of drawings]

1 to 3 show a mounted component inspection apparatus according to an embodiment of the present invention. FIG. 1 is a perspective view of an optical system, FIG. 2 is an explanatory view of a height measuring principle, and FIG. FIG. 4 is a circuit diagram showing the presence of an undetectable part due to a shadow in a conventional one-direction detection type mounting component inspection device, and FIG. 5 is an influence of specular reflection in a conventional two-direction detection type mounting component inspection device. FIG. 1 ... He-Ne laser, 4 ... Polygon mirror, 5 ... f
・ Θ lens, 6 …… Stage, 7, 8 …… Reflecting mirror,
9, 10 ... Imaging lens, 11, 12 ... PSD (position detection element), 13, 14 ... Subtraction circuit, 15, 16, 17, 18 ... Comparison circuit, 19 ... Average circuit, 20 ... Selector circuit, 1 ₁ ... laser light, 1 ₁ , 1 ₃ ... reflected light, P ... printed board, Q ... inspected part, R ... board.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Yuji Maruyama 3-10-1 Higashisanda, Tama-ku, Kawasaki City, Kanagawa Prefecture Matsushita Giken Co., Ltd. No. 10 No. 1 Matsushita Giken Co., Ltd. (56) References JP-A-63-128242 (JP, A) JP-B-61-53643 (JP, B2)

Claims (3)

[Claims] 1. A light irradiating device for vertically scanning a light beam onto a test object having a component mounted thereon, and a reflected light obtained from the test object by the irradiation of the light beam. Two-dimensional optical images are detected from two directions that are symmetrical with respect to the main scanning direction, and luminance data corresponding to the reflectance of the inspection target and height data corresponding to the height of the inspection target are output. And a first comparing means for comparing whether or not each PSD and two types of luminance data output from these PSDs are within a predetermined range that defines a minimum value and a maximum value, respectively, and the above two types of luminance. Second comparison means for comparing the difference between the data and the predetermined value of the brightness difference, and a third comparison for comparing the difference between the two types of height data output from the PSD and the predetermined value of the height difference. Means and the average value of the above two types of height data And Mel averaging means, the first,
A mounting component inspection apparatus comprising: a selection unit that selects either one of the two types of height data or the average value as the combined height data according to the comparison result of the second and third comparison units. 2. When the two types of brightness data are both within a predetermined range that defines a minimum value and a maximum value, and the difference between the two types of brightness data is larger than a predetermined value of the brightness difference, the above-mentioned 2
Of the height data of the types, the height data corresponding to the larger luminance data is selected as the combined height data, and
When all types of luminance data are within the above-mentioned predetermined range and the difference between the two types of luminance data is smaller than the predetermined value of the luminance difference, the average value of the two types of height data is selected as the combined height data. The mounted component inspection device according to claim 1, wherein 3. The two types of brightness data are both within a predetermined range defining a minimum value and a maximum value, and the difference between the two types of brightness data is smaller than a predetermined value of the brightness difference, and 2
When the difference between the height data of the types is smaller than the predetermined value of the height difference, the average value of the height data of the two types is selected as the combined height data, and only one of the luminance data of the two types has the predetermined value. When it is within the range, the height data corresponding to the brightness data is selected as the combined height data, and when neither of the two types of brightness data is within the predetermined range, or the difference between the two types of height data. 2. The mounted component inspection apparatus according to claim 1, wherein the two types of height data are not adopted as the combined height data when is larger than a predetermined value of the height difference.