JPH06167314A - Measuring method of flatness of lead - Google Patents

Abstract

PURPOSE:To prevent the generation of measuring errors to the actual levitating amount of a lead when the lead includes an extreme deformation, e.g. when the lead is inclined or short at the processing time of the binary image of the photographed image of the lead. CONSTITUTION:In order to process a binary image, a binary screen photographed by a CCD camera 20 is divided per line and per pixel in the horizontal direction and vertical direction of a reference surface, respectively, and a [0, 1] evaluation of the screen is carried out (0; a bright point, 1; a dark point). All the bright points (0 evaluation) to an end of the lead, that is, all the bright points at a part of the screen where the lead is present are counted, which is multiplied by the resolution of the CCD camera 20 thereby to calculate the levitating amount of the lead. Moreover, a binary search algorithm with a back track function added is used for an operating means at this time, and therefore, errors when the levitating amount, the flatness of the lead are measured are prevented. At the same time, output data of the levitating amount of each lead corresponding to the lead No. can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead flatness measuring method for a surface mount type integrated circuit package (hereinafter referred to as SMD), and more particularly to a binary search algorithm having an image processing technique and a backtrack function. The present invention relates to a lead flatness measuring method using the above-mentioned calculating means.

[0002]

2. Description of the Related Art Conventionally, when measuring the lead flatness of S / M / D4, the side surface of S / M / D4 is measured by a two-dimensional CCD camera 5.
The image obtained by capturing the image is processed by the system CPU 11b including the horizontal scanning unit 13, the vertical profile counter 21 and the flatness calculating unit 22 as shown in FIG.

First, assuming that the horizontal scanning section 13 is near the bottom of the S, M, and D4 in the binarized memory 9, each pixel on the same line is read from left to right in accordance with a read scan line 23 previously provided by the CPU 14. Progress the horizontal scanning while distinguishing the light and darkness of. From the pixels that have changed from the bright point to the dark point, the continuous section until the dark point changes to the bright point again is recognized as a lead. Here, in the section that the horizontal scanning unit 13 recognizes as read, the vertical profile counter unit 21
All pixels in the same column below the read scan line 23 are vertically scanned, and the total number of bright points in the scanning process (dotted line) is counted as shown in FIG. 9, and the counting result and the read start point of vertical scanning are read. The pixels on the scan line 23 are converted into coordinates in the binarization memory 9, and the memory unit 12
The flatness calculation unit 22 determines the minimum value of all the number of continuous bright points, that is, the floating amount of the lead, based on the numerical data stored in the data cell. Flatness calculation unit 2
Reference numeral 2 retrieves the maximum value from all the data stored in the memory unit 12 and sets it as the read flatness of the S, M, D4. The result is transferred to the CPU 14, and the CPU 14 multiplies all the data transferred from the flatness calculation unit 22 by the resolution of the two-dimensional CCD camera 5 stored in advance, and converts the converted real value in advance. A pass / fail judgment (passing within the standard) was made with respect to the stored standard of the lead flatness, and the result was displayed on the CRT 15 via the I / O 10.

[0004]

With the conventional image processing means, when the lead flatness is obtained from the binarized image, as shown in FIGS.
When the lead is extremely deformed as shown in C (inclined FIG. 9A, C, or short in FIG. 9B), the inclined lead A, C recognizes the presence of the lead in the horizontal read scan line 23. Vertical profile counter 21
Is larger than the actual lead floating amount because the presence or absence of the lead is searched for in the section where the lead is recognized by the horizontal lead scan line 23 and the total number of bright points from the side surface of the lead to the reference plane 26 is counted. There is a problem. Further, the short lead B cannot be recognized by the horizontal read scan line 23.

[0005]

According to the present invention, as an image processing means, the side surface of the S, M, and D4 is picked up by the CCD camera 5 or 20, and the reference plane 26 of the screen is horizontally line by row and vertically by pixel unit. And a means for recognizing leads by dividing (horizontal parallel lines in FIG. 216) with each other, a means for converting the recognized lead portions into numerical data, and a binary search algorithm having a backtrack function in the data operation processing means. ing.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

FIG. 1 is a system configuration diagram of an S / M / D lead flatness measuring apparatus which embodies the lead flatness measuring method of the present invention, and FIGS. 2 and 3 show one-dimensional side views of S / M / D4. CC
The image is captured by the D camera 20, and the binarization memory 9 and the system C are used.
CRT 15 of binarized image binarized by PU 11a
A screen display diagram, FIG. 4 is a tree display diagram of a measurement data processing process processed by the backtrack function, and FIG.
5 is a flowchart illustrating a process of FIG. 4.

The S, M, and D4 to be measured are positioned on the milky-white resin protrusion 3 provided on the measuring stage 2 along the side surface of the mold and the inner surface of the lead, and the light emitted from the light source 1 from below the measuring stage 2 is measured. By irradiating after diffusing at the milky-white resin protrusion portion 3, the lead image of the S, M, and D4 is projected on the one-dimensional CCD camera 20. The one-dimensional CCD camera 20 takes in the projected image and converts it into a video signal. The video signal is amplified by AMP6, digitized by A / D7, and then temporarily stored in the frame memory 8,
The binarization level stored in the CPU 14 is compared to be binarized to [0, 1] (0; bright point, 1; dark point) and stored in the binarization memory 9. One-dimensional CCD camera 20a,
20b, 20c, 20d, 20e, 20f, 20g, 2
A total of 8 units of 0h are used as pulse motor controllers 24a, 2
4b, 24c, 24d, 24e, 24f, 24g, 24
The lead image is successively accumulated in the binarization memory 9 while stepping up by the range of existence of the lead by h. For the binarized data of the stored lead image, the horizontal scanning unit 13 steps up vertically by one pixel unit with respect to the reference plane 26, and the horizontal scanning unit 13 confirms whether or not there is a lead by [0, 1] determination. Then, the total number of bright points, that is, the floating amount from the 0 determination, that is, the bright point portion to the 1 determination, that is, the presence of the lead (lead tip) is counted. The CPU 14 multiplies the count result of the horizontal scanning unit 13 by the resolution of the one-dimensional CCD camera 20 stored in advance to calculate the lead floating value.

FIG. 3 is a diagram for explaining the backtrack function, and FIG. 4 is a tree diagram showing the result of the processing of the backtrack function. FIG. 5 is a flow chart of the backtrack function when obtaining the result of FIG.

According to the image processing method for the lead image described above,
First, 15 which is the minimum lead floating amount in the binarized screen is detected. The CPU 14 searches the left side of the same screen where the lead is processed based on the lead l5, which is the minimum floating amount that stores the number of horizontal steps from the reference surface 26 when the l5 is detected, in the center address of the memory unit 12. . The minimum lead floating amount l1 in the search is detected, and the horizontal step number at this time is stored in the memory unit 12 at the left address of the data of l5. Next, the left side of the lead l1 detected here is searched. Since there is no lead on the left side of the same screen of the minimum floating amount lead 11 as the reference, the lead on the right side of the same screen is searched. Then the smallest l3 in the search
Lead is detected. The floating amount of the lead of l3 is stored in the right address of l1. Then, when the left side is searched with the l3 as a reference, l2 is detected and stored at the left address of l3. There is no lead even if the left and right sides of the l2 lead are searched, and there is no unmeasured lead on the left side based on l3. When the right side is searched next, l4 is detected and stored at the l3 read right address. Since there is no right or left lead from l4, the process first returns to l5 which is the reference lead. Here, the right side is searched based on l5. After that, similarly, S, M, D based on the lead determined to have the smallest floating amount during the search
Search the left side of the binarization screen of 4. When the lead with the smallest floating amount is detected during the search, the left side of the screen is searched based on the lead, and the right side is searched when there are no unmeasured leads. Hereinafter, FIG. 4 is a diagram showing the processing result obtained by repeating this processing. This image processing is performed by the processing means described above regardless of which lead has any floating amount.
-The lead numbers of M and D4 match the order counted from the left side of the captured lead image. The pass / fail judgment of the device with respect to the standard (passing within the standard) is judged by the lead flatness. The read flatness is arranged in the ascending order of the read numbers by the above process, and the maximum value is retrieved by the CPU 14 from the stored data in the memory section 12, and the read flatness of the measured S, M, D4 is measured. As a result, the pass / fail result is compared with the pass / fail judgment standard stored in advance, and
To display.

In FIG. 6, in the system embodying the present invention, the one-dimensional CCD camera which is the optical system of the above-mentioned embodiment is replaced with the two-dimensional CCD cameras 5a, 5b, 5c, 5d, 5e, 5f,
This is an example in which a total of 8 units of 5g and 5h are used. The binarized image of the S, M, and D4 leads captured by the two-dimensional CCD camera 5 is processed at the binarized level stored in the CPU 14,
It is displayed on the CRT 15 together with the pass / fail judgment.

The steps of measuring and positioning before this and all steps of the apparatus system, such as the method of processing the binarized image, are the same as those in the above-described embodiment, and therefore will be omitted. As a result,
Since the two-dimensional camera is used in the imaging process, the pulse motor controller is not used, the step error of the pulse motor is not included, and the output time of the determination result is further shortened.

[0013]

As described above, according to the present invention, the lead floating amount is measured by using the image processing means for scanning in the horizontal direction in the unit of row and in the vertical direction in the unit of one pixel and the binary search algorithm added with the backtrack function. In doing so, it is possible to solve the erroneous recognition in the floating amount of the extreme lead deformation (FIGS. 2A, 2B and 2C) which was erroneously recognized in the conventional image processing means.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a lead flatness measuring device.

FIG. 2 is a binarized image and pixel division diagram obtained by a two-dimensional CCD camera.

FIG. 3 is a binarized image diagram used for explaining a binary search algorithm as a data processing unit.

FIG. 4 is a processing result diagram obtained by a backtrack function which is a binary search algorithm.

FIG. 5 is a flowchart of a backtrack function.

FIG. 6 is a configuration diagram of a lead flatness measuring device according to a second embodiment.

FIG. 7 is a configuration diagram of a conventional lead flatness measuring device.

FIG. 8 is a flowchart of a conventional lead floating amount.

FIG. 9 is a diagram showing a state that has been a conventional problem.

[Explanation of symbols]

 1 light source 2 measurement stage 3 measurement stage protrusion 4 SMD 5a, b, c, d two-dimensional CCD camera 6 AMP 7 analog-digital converter 8 frame memory 9 binary memory 10 I / O 11a, b system CPU 12 memory 13 horizontal Read scan line 14 CPU 15 CRT 16 Horizontal parallel line for pixel processing 17 Reflector 18 Lens 19 Positioning block 20a, b, c, d One-dimensional CCD camera 21 Vertical profile counter 22 Maximum value calculator 23 Horizontal line 24a, b, c , D Pulse motor controller 25 False recognition part in image processing means before 26 26 Reference plane

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[Procedure amendment]

[Submission date] June 22, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction content]

According to the image processing method for the lead image described above,
First, the minimum lead floating amount of 15 in the binarized screen is detected. The CPU 14 searches the left side of the same screen where the lead is processed based on the lead 15 which is the minimum floating amount that stores the number of horizontal steps from the reference surface 26 when 15 is detected in the center address of the memory unit 12. . The smallest floating amount lead 11 is detected in the search, and the horizontal step number at this time is stored in the left address of the data of 15 in the memory unit 12. Next, the left side of the lead 11 detected here is searched. Since there is no lead on the left side of the same screen of the minimum floating amount lead 11 as a reference, the lead on the right side of the same screen is searched. Then the smallest 13 in the search
Lead is detected. The floating amount of the lead of 13 is stored in the right address of 11. Next, when the left side is searched with the 13 as a reference, 12 is detected and stored at the left address of 13. There is no lead even if the left and right sides of 12 leads are searched, and there are no unmeasured leads on the left side with reference to 13, and when the right side is searched next, 14 is detected and stored at the 13 lead right address. Since there is no lead on either the right or the left from 14, the procedure first returns to 15, which is the reference lead. Here, the right side is searched based on 15. After that, similarly, S, M, D based on the lead determined to have the smallest floating amount during the search
Search the left side of the binarization screen of 4. When the lead with the smallest floating amount is detected during the search, the left side of the screen is searched based on the lead, and the right side is searched when there are no unmeasured leads. Hereinafter, FIG. 4 is a diagram showing the processing result obtained by repeating this processing. This image processing is performed by the processing means described above regardless of which lead has any floating amount.
-The lead numbers of M and D4 match the order counted from the left side of the captured lead image. The pass / fail judgment of the device with respect to the standard (passing within the standard) is judged by the lead flatness. The read flatness is arranged in the order of increasing the read No by the above processing, and the maximum value is retrieved by the CPU 14 from the stored data in the memory section 12, and this is determined as the read flatness of the measured S / M / D4. As a result, the pass / fail result is compared with the pass / fail judgment standard stored in advance, and
To display.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction content]

[0013]

As described above, according to the present invention, by using the image processing means for scanning the row unit in the horizontal direction and the pixel unit in the vertical direction and the binary search algorithm with the backtrack function, the conventional image can be obtained. In the processing means, the extreme lead deformation that was erroneously recognized (FIG. 2A,
(B, C) The erroneous recognition of the floating amount can be solved, and the obtained data is used to calculate the lead floating amount of the surface mount type integrated circuit package while backtracking and to increase the lead number in order. Can be arranged.

[Procedure 3]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 1

[Correction method] Change

[Correction content]

[Figure 1]

[Procedure amendment 4]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 6

[Correction method] Change

[Correction content]

[Figure 6]

Claims (1)

[Claims] 1. In the lead flatness measurement of a surface mounting type integrated circuit package, a means for imaging the side surface of the surface mounting type integrated circuit package and binarizing the obtained image data, and observing the binarized data. Means for recognizing the lead portion, means for replacing the recognized lead portion with numerical data, and means for processing the numerical data, the floating amount of each lead of the surface-mounted integrated circuit package while backtracking. And a lead flatness measuring method which calculates a lead flatness and uses a binary search algorithm for arranging the leads in ascending order of numbers.