JPH10283479A - Device for recognizing lead and storage medium for recognizing lead and device for measuring appearance of electronic part using the same device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce labor or time necessary for the setting of a parameter or an inspection area. SOLUTION: At the time of inspection using a picture obtained by image picking up an IC part unit by a camera, an operator sets a rectangular area 20 crossing all leads 17 of a part on a picture displayed on a monitor. A CPU extracts luminance distribution on a line for each line l1 -l4 constituting the rectangular area 20, and an area, in which the change of contrast repeatedly appears with the similar displacement amounts and similar pitches, is recognized as the position of the lead column.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for measuring leads of an electronic component having a plurality of leads on an outer periphery by using an image processing technique.

[0002]

2. Description of the Related Art In a general manufacturing process of an IC component, a process of punching a metal ribbon to form a lead pattern,
A step of mounting the IC chip on the formed lead pattern, a step of molding the IC chip with a resin, and the like are performed to manufacture a component unit in which the outer periphery of the IC component body is protected by the frame. Further, a tie bar (a pattern formed between the leads for fixing the leads at the time of forming the lead pattern), a process of separating the leads from the frame, and leads adjacent to the four corners of the mold are applied to the component unit. A process of separating the other metal patterns is performed, and each lead is bent to complete a component in a final form.

[0003] In such a manufacturing process, inspection is performed on the component unit before the component main body is cut off, for the appropriateness of the lead pitch, shape, and length, and for a tie bar cut defect (called "tie bar uncut"). Have been done.

When performing these inspections, prior to the inspection, in addition to the parameters obtained by the calibration, the number of leads, the length and width of the leads, and the distance between the leads (hereinafter referred to as "below") for each type of component to be inspected. Various parameters such as "lead pitch") and the size of the mold need to be set in the apparatus. After the setting process is completed, the image of the component unit to be inspected is taken into the apparatus, and the operator sets an inspection area on the input image displayed on the monitor. A measurement process required for the inspection is performed using the data, and the obtained measurement result is output to a monitor or the like.

[0005]

Conventionally, setting of the various parameters has been performed manually by an operator. However, in order to set correct parameter values, it is premised that accurate information of various parts is known, so that a heavy burden is imposed on the operator. There is also a problem that it takes time to input the parameter value.

When an inspection area is set on an image, an operator must accurately specify a position on the image where each lead is included. However, since each lead and lead pitch are extremely small, it is not easy to accurately specify only the lead portion.

FIG. 7 shows an example of setting an inspection area. In the figure,
The white part is the metal part, 15 is the lead and 1 is
Reference numeral 6 denotes a pattern other than the lead. Further, the shaded portion is an image region having lower luminance than these metal portions, and 17 indicates a mold and 18 indicates a frame, respectively. In such a component, here, inspection regions 19a to 19d are set so as to cover only the lead portions in each of the arrangement directions of the leads. Since the interval between the lead portion and the pattern other than the lead in the actual component is extremely small, it is extremely difficult to accurately separate the two on the image and set an area.

The present invention has been made in view of the above problem, and automatically sets parameters necessary for measurement processing by setting a rectangular area that crosses all leads on an image. Another object of the present invention is to greatly reduce the labor and time required for setting parameters and inspection areas.

[0009]

According to a first aspect of the present invention, there is provided a lead recognizing apparatus, comprising: image input means for inputting an image obtained by imaging an electronic component having a plurality of leads on an outer periphery; Setting means for setting a rectangular area that intersects all the leads, and recognition means for recognizing the position of the lead based on the luminance distribution on each line constituting the rectangular area.

In the invention according to claim 2, the recognizing means extracts, as the position of the lead, a portion where a change in lightness and darkness appears at a regular pitch on each of the lines, and recognizes the lead pitch based on the pitch of the change. It is configured to

According to a third aspect of the present invention, the recognizing means extracts, as the position of the lead, a portion where a change in lightness and darkness appears at a regular pitch on each of the lines, and extracts the electron from the number of the extracted pitches. It is configured to recognize the number of leads of the component.

According to a fourth aspect of the present invention, there is provided a storage medium for recognizing a lead having a rectangular area crossing all leads on an image obtained by imaging an electronic component having a plurality of leads on an outer periphery. The first step of receiving the setting and the second step of extracting the position of the lead based on the luminance distribution of each line constituting the set measurement area are stored so as to be performed in series.

According to a fifth aspect of the present invention, there is provided an electronic component appearance recognizing device including the same image input means, setting means, and recognizing means as in the first aspect, and image data of a predetermined image area based on a recognition result by the recognizing means. And a measuring means for extracting and extracting measurement data.

[0014]

According to the first and fourth aspects of the present invention, when a rectangular area that intersects all the leads of the component is set on an image obtained by imaging the component to be measured, the rectangular area is set. Since the position of the lead is automatically recognized based on the density distribution on each of the constituent lines, there is no need to set the inspection area in detail or input parameters. According to the fifth aspect of the present invention, it is possible to accurately extract an image of a position where an electronic component is to be measured by performing a measurement process using image data of a predetermined image region based on a recognized result, and perform accurate measurement. it can.

According to the second and third aspects of the present invention, a portion where a change in lightness and darkness appears at a regular pitch on each line is extracted as a lead position. Further, based on this extraction result, the lead pitch in the invention of claim 2 and the number of leads of the electronic component in the invention of claim 3 are automatically recognized.

[0016]

FIG. 1 shows the configuration of a visual inspection apparatus according to an embodiment of the present invention. This visual inspection apparatus captures an electronic component and performs a measurement process using an image of the lead portion, thereby obtaining the length, shape, lead pitch, and lead pitch of each lead.
This is for performing inspections related to tie bar uncut, etc., and includes a television camera 1 (hereinafter simply referred to as “camera 1”), an A / D converter 2, a D / A converter 3, a monitor 4, an image memory 5, and a character.・ Graphic memory 6, CP
It includes a U7, a memory 8, an input unit 9, an output unit 10, and the like.

The analog amount of image data picked up by the camera 1 is converted by the A / D converter 2 to create digital amount of image data represented by a higher numerical value for a pixel having higher luminance. The image data is stored in the image memory 85 via the image bus 11, and at the same time, is decoded by the D / A converter 3 into data of an analog amount and output to the monitor 4. The character / graphic memory 6 stores data for displaying a message, a cursor, and the like on the monitor 4 screen when setting an area described later.

The memory 8 has an area for storing a control program previously installed from a storage medium such as a floppy disk or a CD-ROM, and a memory for temporarily storing various data generated when the control program is executed. A work area is formed.

The CPU 7, which is the main control unit, is a CPU bus 1
2 to access the image memory 5 and execute a measurement process on the image data based on the control program. This processing result is provided to the output unit 10 and then output to the monitor 4 or an external storage device (not shown). The input unit 9
Is for inputting setting data such as the type of component to be inspected.

FIG. 2 shows a series of processing procedures related to the lead inspection. Hereinafter, the details of the inspection will be described along the flow of FIG. 2 with reference to FIGS. First, in step 1 (indicated by "ST1" in FIG. 2), when a part to be inspected is imaged by the camera 1, this image is digitally converted by the A / D converter 2 and stored in the image memory 5. .

At this time, an image via the D / A converter 3 is displayed on the monitor 4 and the next step 2
Then, the operator sets a rectangular area of a predetermined size on the image of the component while referring to the display screen. FIG.
Shows an example of setting of this rectangular area. In an image similar to that shown in FIG. 7, a rectangular area 20 which intersects all leads on this image is set.

When the above setting is completed, the CPU 7 pays attention to each of the lines l _{1 to} l ₄ constituting the rectangular area and extracts a luminance change on each line. Further CPU7
Using the maximum and minimum points of luminance on this change curve,
A region where the change in lightness and darkness repeatedly appears with the same shift amount and the same pitch is extracted, and this region is recognized as the position of the lead row. Further, the CPU 7 recognizes the lead width, the lead pitch, the number of leads, and the like based on the luminance change pattern in the area (step 3).

FIG. 4 shows a luminance change curve on a predetermined line (for example, line l ₁ ).
Peaks P _A and P _B having large widths reflecting the pattern 16 other than the lead respectively appear. Also, in a region R between these peaks P _A and P _B , peaks p ₁ , p ₂ , p ₃ ... _Pn having a small width reflecting each lead appear continuously at the same pitch. I have. The CPU 7 compares the luminance change in the region R with a predetermined threshold value th, sets the interval v ₁ , v ₂ ... Of the peaks exceeding this th as the lead width of each lead, and the valley below the th. the interval w _1, w ₂ ··· as lead pitch, recognizes each. Also, by summing the number of peaks extracted for each of the lines l _{1 to} l ₄ , the number of leads of this component is recognized.

In the next step 4, the CPU 7 measures the lead lengths of the extracted peak vertices q ₁ , q ₂ , q ₃ ... For each of the lines l _{1 to} l _4. and sets as the search start point for, based on the v ₁ it is recognized lead width, v _2, v _3, to determine the search width for this measurement processing.

This measurement process is performed for each search start point on the inner side (ie, on the mold side) starting from that point.
In addition, the CPU 7 traces the constituent pixels of the lead toward the outside (ie, the frame side). The CPU 7 first performs a tracking process toward the inside from this point q ₁ for the first search start point q ₁ , and The intersection with the mold is extracted (step 5).

FIG. 5 shows a specific example of the above tracking process. In the figure, each rectangle indicates one pixel, and the number in each rectangle indicates the luminance of the pixel. First, the CPU 7 pays attention to the pixel g ₀ located one pixel inside from the search start point q _{1, and} a pixel (here, q ₀ , q ₁ , q _{1) corresponding} to a search width defined around the pixel of interest g _0. (3 pixels ₂ ) is set as the measurement target. Next, the CPU 7 specifies a pixel (g _{1 in the} illustrated example) having the highest luminance value among these pixels g ₀ , g ₁ , and g ₂ as a tracking point.

Similarly, pixels having a search width one pixel inward from the tracking point are set as measurement targets, and the pixel having the highest luminance value is specified as a new tracking point from among the pixels. Each rectangle indicated by the overlapping frame is sequentially associated.

The CPU 7 recognizes these tracking points as representative constituent points indicating the length direction of the lead, and associates the position of each tracking point with its luminance as shown in FIG.
Remember in Each time a new tracking point is specified, the CPU 7 compares the luminance value of the tracking point with a predetermined threshold value TH. When the luminance at any one of the tracking points falls below this threshold value TH, This tracking point (cp in the figure) is specified as the intersection between the lead and the mold, and the tracking processing ends.

[0029] In this way, the lead inside end point is recognized, CPU 7 is again focused on the search start point q _1, to start a similar tracking process towards than the search start point q ₁ to the outside. As a result, when a tracking point lower than the threshold value TH is similarly obtained, the CPU 7 specifies this tracking point as an intersection between the lead and the frame, and ends the tracking processing (step 6).

When each intersection is specified in this way, C
The PU 7 calculates the distance between these intersections, and uses the calculation result as a measured value of the lead length (step 7). Further, by comparing the measured value with a predetermined reference value, it is determined whether the length of the lead is appropriate. By checking the change in the position of each tracking point, the suitability of the lead shape is determined (step 8).

In the same manner, by performing the processing of steps 5 to 8 using all the set search start points, if it is determined that the length of each lead is appropriate, step 9 is performed.
Becomes “YES”, and proceeds to step 10.
7 outputs each determination result to the output unit 10 and ends a series of processing.

When the tie bar uncut is to be inspected, one point corresponding to the point of the groove between the leads for each of the lines l _{1 to} l _{4 is} determined using the lead pitch recognized in step 3. Set as search start point. Thereafter, the same search processing as described above is performed inward from the search start point, and when a tracking point below a predetermined threshold is obtained, the tracking point is specified as an end point of the groove. As a result, if the distance from the search start point to the extracted end point is shorter than a predetermined reference value, it is determined that the tie bar is left uncut.

[0033]

As described above, according to the present invention, the position of a lead to be inspected can be automatically set by simply setting a rectangular area that intersects all leads on an image obtained by imaging an electronic component. Since it is configured so that it is automatically extracted, it is not necessary to set various parameters and the exact position of the inspection area as in the related art, and the setting for the inspection can be easily performed in a short time. In addition, since the inspection can be performed even if the operator is not familiar with the external size of the component to be inspected, the labor and the burden on the operator are greatly reduced.

According to the second and third aspects of the present invention, it is possible to extract a lead position by extracting a portion where a change in lightness and darkness appears at a regular pitch on each of the lines. Further, based on the extraction result, the lead pitch can be automatically recognized in the invention of claim 2, and the number of leads of the electronic component can be automatically recognized in the invention of claim 3.

According to the fourth aspect of the present invention, an apparatus for executing the recognition processing can be easily provided by configuring a storage medium for storing the procedure for the recognition processing of the read position.

According to a fifth aspect of the present invention, an image of a position where an electronic component is to be measured is accurately extracted by a measurement process using image data of a predetermined image area based on a recognized result, and accurate measurement is performed. be able to.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a visual inspection apparatus according to an embodiment of the present invention.

FIG. 2 is a flowchart illustrating a control procedure according to a lead inspection.

FIG. 3 is an explanatory diagram showing a setting example of a rectangular area.

FIG. 4 is an explanatory diagram showing the principle of the lead position recognition process.

FIG. 5 is an explanatory diagram showing a specific processing procedure for tracking the length direction of a lead.

FIG. 6 is an explanatory diagram showing a method of extracting an intersection between a lead and a mold.

FIG. 7 is an explanatory diagram showing a conventional example of setting an inspection area.

[Explanation of symbols]

Reference Signs List 1 camera 5 image memory 7 CPU 8 memory 16 lead 20 rectangular area l _{1 to} l ₄ lines

Claims (5)

[Claims] 1. An image input means for inputting an image obtained by imaging an electronic component having a plurality of leads on an outer periphery, and a rectangular area intersecting all leads is set on the input image. And a recognizing means for recognizing a lead position based on a luminance distribution on each line constituting the rectangular area. 2. The apparatus according to claim 1, wherein said recognizing means extracts a portion where a change in lightness and darkness appears at a regular pitch on each of the lines as a position of the lead, and recognizes a lead pitch based on the pitch of the change. The lead recognition device described. 3. The recognizing means extracts, as the position of the lead, a portion where a change in lightness and darkness appears at a regular pitch on each line, and determines the number of leads of the electronic component from the number of extracted pitches. The lead recognition device according to claim 1, wherein the recognition is performed. 4. A first step of receiving a setting of a rectangular area that intersects all leads on an image obtained by imaging an electronic component having a plurality of leads on the outer periphery; A second step of extracting the position of the lead based on the luminance distribution of each line constituting the measurement region; and a storage medium for read recognition stored in a series. 5. An image input means for inputting an image obtained by imaging an electronic component having a plurality of leads on the outer periphery, and setting a rectangular area crossing all leads on the input image. Setting means for recognizing, a recognizing means for recognizing a lead position based on a luminance distribution on each line constituting the rectangular area, and extracting and measuring image data of a predetermined image area based on a recognition result by the recognizing means. Apparatus for recognizing the appearance of electronic components, comprising: a measuring means for performing processing.