JPH01236700A - Inspection and orientation recognition method of component lead - Google Patents

Abstract

PURPOSE:To enable the detection of a lead bending amount and the judgement of a component orientation at the same time by a line sensor camera by a method wherein a lead bending amount is detected and a center position of the whole component is computed from a lead position at the same time, and the positional deviation of the center of the component from the center of a package is computed. CONSTITUTION:A binary image information, obtained by imaging each lead side of a component 6 through a line sensor camera 6, is stored in a memory 8, a lead position and a pitch between leads are obtained from the image information of the memory 8, and a center position of a lead side is computed the position of the lead whose right and left pitches are equal to from other. Here, if a component is provided with four lead sides, a center position of the whole component and the positional deviation amount of the center position based on the lead as a datum are computed from the center position of each lead side, and the positional correction of the component is performed corresponding to the obtained positional deviation amount. And, the image of the lead side of the positionally corrected component is imaged again by the line sensor camera 6, binary image information is stored in the memory 8, and it is confirmed from the image information whether the correction is complete or not. By these processes, a lead bending inspection and an orientation judgement can be performed at the same time using the line censor camera.

Description

[Detailed Description of the Invention] [Summary] Regarding the bending inspection of the lead portion of a component and the posture recognition method of the component, the purpose of the present invention is to determine the posture of the component and detect the amount of bending of the lead portion using a line sensor/camera. A sensor camera images each lead side of the component, converts the multi-valued image information into binarized data and stores it in memory. Based on the binary image information on the memory, determines the lead position and the bit between leads, and determines the left and right pitch. Calculate the center position of the lead sides from the lead positions where the values are equal, ■ For parts with lead sides on four sides, calculate the center position and positional deviation of the entire part from the center position of each lead side, and ■ Calculate the positional deviation amount. Correct the position of the component according to For parts with lead sides on only two sides, calculate the center position and displacement amount of the entire part from the center position of the lead sides and the lead tip (or root) position.9 [Industrial Application Field] TECHNICAL FIELD The present invention relates to a method for inspecting bending of leads of flat lead package type components, which has been increasing in recent years, and for recognizing the posture of the component.

[Conventional technology]

Conventionally, bending of the leads of flat lead package type components has been inspected using area cameras or line sensors.
A method has been adopted in which the lead portion of the component is imaged with a camera, the video signal is A/D converted, and the amount of bending of the lead portion is measured using a digital signal.

[Problems to be Solved by the Invention] However, as the target parts become smaller and the lead parts and printed board patterns become smaller, in order to obtain sufficient measurement accuracy, (a) In the area camera, one of the CCD elements Because the number of pixels that pass through light is small, it is necessary to increase the magnification of the imaging optical system and capture images hundreds of times.

(6) Since the line sensor/camera can only obtain image information for one line in one image capture, measurement errors are likely to occur due to misalignment between the target part and the line sensor/camera.
It is necessary to recognize the orientation of parts and perform highly accurate position correction.

There were other problems.

In the above method, if the line sensor and the component to be inspected are misaligned, the pitch information between the leads will be different. In addition, when placing the component on a predetermined pattern on the printed board after inspecting the lead edge, it is necessary to align the center position of the package with the pattern on the printed board because the component package has considerable distortion during manufacturing. Even if you do this, it may not always be possible to implement it accurately. Therefore, in order to perform accurate alignment,
It is necessary to find the center position of the entire component (package and leads) from the component lead position and correct the positional deviation from the center position of the package.

The present invention has been created in view of this point, and its object is to simultaneously determine the posture of a component using a line sensor/camera and to detect the amount of bending of a lead portion.

[Means for solving the problem] FIG. 1(a) is a diagram of the principle of the first invention of the present invention;
Figure (b) is a diagram of the principle of the second invention. The present invention
The amount of lead bending is detected, and at the same time, the center position of the entire component is calculated from the lead position, and the amount of positional deviation from the center of the package is calculated. The first invention relates to a component having lead sides on four sides, and includes: (1) A line sensor/camera is used to image each lead side of the part, and the line sensor/camera outputs multi-valued image information. Binarize and store the binary image information in the memory. ■ Based on the binary image information on the memory, find the lead position and pitch between leads, and calculate the center position of the lead side from the lead position where the left and right pitches are equal. ■ For parts that have lead sides on all four sides, calculate the center position and positional deviation of the entire part based on the lead from the center position of each lead side, and ■ Calculate the positional deviation of the part according to the calculated positional deviation. After performing position correction, ■ Image the lead side of the component whose position has been corrected again using a line sensor camera, store binary image information in memory, and complete correction based on the binary image information in memory. The configuration requirement is to confirm whether or not this is the case.

The second invention relates to a component having lead sides only on two opposing sides, and the tip of the lead (or attached jif)
i) The position is determined, and the center position and positional deviation amount of the entire component with respect to the lead are calculated from the center position of each lead side and the tip (or root) position of the lead. The other points are the same as the first invention.

[Embodiment] FIG. 2 is a block diagram showing an example of the system configuration of the present invention. The illumination section 1 is arranged above the component 3 to be inspected, and a white light diffusing plate 2 is installed between the light emitting surface of the illumination section 1 and the component 3 in order to obtain a clear image of brightness and darkness. The imaging unit includes a camera lens 5 and a CCD line sensor camera 6.
etc., the image is taken from below the part to be inspected 3,
A silhouette image of the lead section is taken. The image processing unit includes a microprocessor 10 that performs data processing, a camera interface 7 that A/D converts an analog signal from the CCD line sensor camera 6 based on a control signal from the microprocessor 10, and stores it in a memory 8. A memory 8 for storing digitized image information, a mechanical interface 9, a CRT controller 11 for outputting test results to a CRT, and an external storage device 13 for storing test results.
and an external storage device controller 12.

The mechanical interface 9 is for controlling a robot (not shown) that holds and moves the parts to be inspected and a robot that moves the camera.

FIG. 3 is a diagram showing an inspection flowchart.

A specific inspection method will be explained below. First, the component to be inspected is set at the inspection position (the mounting position on the printed board), and the line sensor/camera is moved to the position of each lead side. Once the sowing point has been moved, a silhouette image of the lead section is taken, and the camera interface is connected to the line sensor.
The analog waveform obtained from the camera is converted into digital by an A/D converter, and its peak value is determined. Next, about 1/2 or 1/3 of the obtained peak value is set as a dark value and the image is captured again by the line sensor camera, and while comparing the camera output wave and the above dark value with a comparator, the brightness level is "0°".
Load the binary image of ° or °“1'' into the memory.

The number of positions n is determined by counting the bit positions of the brightness level "0" indicating the lead part in the binary image information on this memory, and the lead part of the normal component determined in advance is imaged with the optimal darkness value. Compare the number of positions N of brightness level "0" indicating the lead part in the binary image obtained by Import the value image and repeat the same operation.

If the number of positions n is sufficiently close to the predetermined value N, the brightness level indicating the edge portion of the lead from the captured binary image will change from "1" to "0'' and from "O11 to "1".
” search for the reversal position and find the lead position and number of leads.

If the number of leads is not equal to the specified value, it will be rejected as broken leads or large positional deviations. If it is equal to the specified value, the center position of the lead portion is set as the lead position, the inter-lead pitch is calculated, and it is stored in the memory. If the part to be inspected is rotating, the pitch will be longer than the normal one. Here, the center position of the lead side is calculated from a plurality of lead positions where the pitch between the left and right leads is equal. FIG. 4 shows an example of a multivalued image and a binary image of the lead portion. A lead position and an inter-lead pitch are calculated based on the binary image.

Furthermore, for parts to be inspected that have only two sides of the lead, by moving the camera back and forth, capturing a binary image, and counting the number of pixels with a brightness level of "O11" that indicates the lead part, the tip (or root) of the lead can be detected. Discover the parts.

Perform the above operation for each side, and for parts with four lead sides, calculate the center position and rotation amount of the entire part with the lead as a reference from the center of the four sides, and for parts with two lead sides, calculate the center position and rotation amount of the entire part with the lead as a reference. The center position and rotation amount of the entire part with the lead as a reference are calculated from the center of the two sides and the position of the lead tip.

FIG. 5 shows the center of the lead sides and the tips of the leads in a component that has leads on only two sides.

Next, it is determined whether the lead-to-lead pitch on each side, which was determined earlier than the determined amount of rotation, is within a specified range. If it is outside the specifications, the lead is bent, so it is rejected, and if it is within the specifications, the position is corrected.

Finally, a binary image is captured again for one side or each side, and it is determined whether the correction is satisfactory based on the lead positions at both ends and the lead positions. A component (for example, LSI 20) that is found to be OK in the inspection shown in FIG. 3 is placed on a printed circuit board 30, as shown in FIG. Ru.

FIG. 7 is a diagram illustrating a method of setting a binarization slice level. When the lead part of a component is imaged with a line sensor as shown in figure (a), the light is blocked at the lead part due to transmitted illumination, and in the case of a multilevel image, the lead part becomes a valley as shown in figure (b). Become. Now, change the slice level to the same figure.■
), you can get 2 if you set it in a place with high brightness like A in
In the value image, as shown in (C) in the same figure, the part with the brightness level "0" that indicates the lead part becomes wide (conversely, if the slice level is set in a place with low brightness as shown in B in (b) in the same figure, As shown in the figure (d), the area at the brightness level "O11" that indicates the lead part is narrower in the obtained 2 (direct) image.In this way, depending on the slice level that is set, the width is 2
The width of the lead part on the value image becomes wider or narrower. In the present invention, the center position of the 0" brightness level part of the binary image is searched to find the position of the lead part, but if the width of the lead part on the binary image is extremely wide,
If it is narrow, the center position will tend to vary. Therefore, the slice level is set so that the actual lead width always matches the lead width of the binary image.

FIG. 8 is a diagram illustrating a method of calculating the center position of the lead side. The obtained binary image is searched for the part with the brightness level "'0", and the center position of each part with the brightness level "0" is determined and set as each lead position Ik.In addition, each of the obtained lead positions .

and the next lead position 1k, ., the inter-lead pitch P can be found. Now, considering lead N+1, the distance between it and the lead on the left side is P 11,
- The distance between the lead on the right side of the book is P, % or 1, and if N+1 is bent, Δp, =! p,,-p,
, , 1 is a large value. Therefore, for each lead, this ΔP
Calculate h, compare with specified value, and inspect for bending. With this method, the θ deviation of the parts will be to some extent (±10＠)
Even if there is, if the lead is not bent, almost ΔP,
ζO, and is not affected much by rotational deviation. Next, check the leads (
For example, if the part is imaged by the line sensor at position N+3) in the figure without any positional deviation, the difference between position Jk and position Jk where the lead is located.

Find Δdm=Jm Im. Δd for each unbent lead,
is calculated, summed, and divided by the number of unbent leads to determine the average positional deviation amount ΔD. The center of the lead side of the component can be found by taking the sum of this ΔD and the center position 2c of the lead side when the component is imaged by the line sensor without positional deviation.

FIG. 9 is a diagram illustrating a method of calculating the center position of the entire component from the leads. First, a component having lead sides on four sides will be explained. The center position of each lead side of the component is determined by the method described above.

So, Sl, and 32.33 in FIG. 3(a) indicate the center position of each lead side in a component having four nirito sides. Furthermore, the coordinates of the center C of the component when the component is not displaced are also known. By using the center positions S0 to S of each side to find two intersections connecting the centers of two opposing sides, the center position C' of the part can be found. Further, the inclination θ of the component is the angle formed by each line segment with the X axis or the Y axis.

Next, a component having lead sides on two sides will be explained. The center position of each lead side of the component is determined by the method described above. SO and SL in FIGS. 3A and 3B indicate the center position of each lead side in a component having lead sides on two sides. Also,
The lead tip position and the coordinates of the center C of the component when the component is not displaced are also known. The intersection of the line segment connecting So and St and the line segment parallel to the X-axis passing through the center position of each lead tip position is the center position C' of the component. Further, the inclination θ of the component is the angle that the line segment connecting So and St makes with the Y axis.

Next, calculation of the amount of positional deviation will be explained. C′ mentioned above
Let the coordinates of the point be (x++y+), and the coordinates of the 0 point be (x (
1+y6).

Now, considering a coordinate system with the origin at point 0, the coordinates of point C' can be converted to C+(X+-Xo+3'+-3'o).

Since the part has an inclination of θ, if it is rotated by -θ around the origin and the position correction in the θ direction is considered, the rotational movement will be Cz(x l+ )'z). This Cz
The coordinates of (xz, yz) are:
yo) sin(-θ)3' z= (X I-X o)
sin (-θ) + 0' I-No) cos (-〇)
becomes.

〔Effect of the invention〕

As is clear from the above description, according to the present invention: (a) Processing speed is fast because a line sensor/camera is used.

(1)) Since the posture is determined at the same time as the lead bending test, there is little measurement error due to positional deviation.

(C) Since the number of pixels per line is greater than that of area cameras, the resolution and accuracy are high.

This remarkable effect can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the principle of the present invention, FIG. 2 is a diagram showing an example of the system configuration of the present invention, and FIG. 3 is a diagram showing an inspection flowchart.
Figure 4 is a diagram showing a multivalued image and a binary image of the lead part, Figure 5
The figure shows the center position of the lead side and the lead tip, Figure 6 shows the LSI and the printed board, Figure 7 shows how to set the binarization slice level, and Figure 8 shows the lead side. FIG. 9 is a diagram illustrating a method for calculating the center position of the entire component from the lead. DESCRIPTION OF SYMBOLS 1... Illumination part, 2... Light diffusing plate, 3... Parts to be inspected, 4... Lead, 5... Camera lens,
6... CCD line sensor camera, 7... Camera interface, 8... Memory, 9... Mechanical interface, 10... Microprocessor, 11.
. . . CRT controller, 12 external storage device controller, 13 . . . external storage device. Patent Applicant Fujitsu Ltd. Representative Patent Attorney Kyotani Yotsube 1 Figure Lead'<f+Jj Lead l? The 7th part of the 7th chapter is the 7th chapter of the 7th Kasumi゛)-do 4f! Ln-I I, 1□rl L
yz kt3 l-I4 lead bend
△ η " △ Ta ^ Reed road u IU/lit/) calculation mourning) (b) 4 pieces of shishinkin 111ji karyu nori h payment fan q diagram

Claims (2)

[Claims] (1) A component lead inspection and posture recognition method that uses a line sensor and camera to inspect bending of the lead portion of a component and recognize the posture of the component. [2] Based on the binary image information on the memory, the lead position and Find the pitch between the leads, calculate the center position of the lead side from the lead position where the left and right pitches are equal, and [3] For parts with lead sides on four sides, use the lead as a reference from the center position of each lead side. Calculate the center position and positional deviation of the entire part, [4] Correct the position of the part according to the calculated positional deviation, and [5] Image the lead side of the part whose position has been corrected again using a line sensor camera. A component lead inspection and posture recognition method characterized in that binary image information is stored in a memory, and whether or not the correction is complete is confirmed based on the binary image information on the memory. (2) A component lead inspection and posture recognition method that uses a line sensor and camera to inspect bending of the lead portion of a component and recognize the posture of the component; [2] Based on the binary image information on the memory, the lead position and Find the pitch between the leads, calculate the center position of the lead side from the lead position where the left and right pitches are equal, and [3] For parts with lead sides only on two opposing sides, calculate the position of the tip [or root] of the lead. [4] Calculate the center position and positional deviation of the entire component based on the lead from the center position of each lead side and the tip (or root) position of the lead, and [4] Correct the position of the part according to the calculated positional deviation. [5] Image the lead side of the component whose position has been corrected again using the line sensor camera, store the binary image information in memory, and check whether the correction is complete based on the binary image information on the memory. A component lead inspection and posture recognition method characterized by confirming whether or not the component lead is present.