JPH0781845B2 - Electronic parts lead shape inspection device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for inspecting lead shapes such as lead pitch and flatness of electronic parts, and more particularly to an apparatus for inspecting lead pitch with high resolution.

[0002]

2. Description of the Related Art For example, a flat package type IC
When mounting electronic components such as (integrated circuits) on a printed wiring board, if the leads of the electronic components are bent or lifted, a connection failure may occur with the terminal portion of the printed wiring board. A device is used to inspect whether the lead shape of a component is within an allowable range.

The structure of a conventional inspection apparatus will be described below with reference to FIG. In the figure, reference numeral 1 is a flat package type IC to be inspected, and a large number of leads 2 are led out from the side portion of the package body 1a. The IC 1 is placed on the inspection stage 3. Package body 1 of IC1
Light is emitted substantially horizontally from a light source (not shown) to the gap between the lower surface of a and the inspection stage 3, and the light passing through the gap between the leads 2 is reflected by the half mirror 4, the reflection mirror 5, and the optical system 6.
It is led to the CCD (charge coupled device) camera 7 via. FIG. 7 shows the IC1 imaged by the CCD camera 7.
Is the read sequence portion of. Reference line O shown by a chain line in FIG.
Corresponds to the surface of the inspection stage 3, and the floating amount W of each lead 2 with respect to the reference line O is measured by an image processing device (not shown). On the other hand, when it is necessary to measure each lead pitch (lead bend) P with high accuracy, the light reflected by the half mirror 4 is guided to the high resolution CCD line sensor 9 through the optical system 8, and The lead pitch is measured based on the output signal.

[0004]

However, the conventional example having such a structure has the following problems. That is, the lead pitch P is preferably measured between the limit value of the floating amount allowed for the lead 2 (line indicated by reference symbol M in FIG. 7) and the package body 1a, as close to the line M as possible. . what if,
When the lead pitch is measured between the reference line O and the line M in FIG. 7, there is a possibility that the lead 2 may be erroneously determined to be missing, although the lead 2 is allowed to float. Because there is. As described above, it is necessary to specify the line for measuring the lead pitch, but it is difficult for the conventional device to determine which line of the captured image shown in FIG. 7 the CCD line sensor 9 is measuring. There is a problem that is.

When measuring the bending amount of the lead 2 (the deformation amount from the base end portion to the tip end portion of the lead 2), the line set on the side closer to the package body 1a in the captured image of FIG. 7 and the floating limit. The lead pitch is measured along each of two lines including the line set on the side close to the line M, and the difference between the two pitches is calculated. In such cases,
According to the conventional device, a driving mechanism for changing the measurement point of the CCD line sensor 9 is provided, or two C
Since the CD line sensor 9 must be used to measure two lines individually, there is a problem that the device configuration becomes complicated in any case.

The present invention has been made in view of the above circumstances, and provides a lead shape inspection device for an electronic component, which is capable of highly accurately detecting the lead pitch of the electronic component along an arbitrary line. The purpose is to do. Also,
Another object of the present invention is to provide a lead shape inspection device for an electronic component, which can easily and quickly measure the lead pitch along a plurality of lines.

[0007]

The present invention has the following constitution in order to achieve such an object. That is, the lead shape inspection device for an electronic component according to claim 1, wherein a two-dimensional image pickup means for picking up the lead arrangement of the electronic component, a display means for displaying the lead arrangement picked up by the image pickup means, and a display means for displaying the lead arrangement. any measurement line setting means for setting a lead pitch measurement line in the horizontal scanning line on a horizontal scan line that will be output from said image pickup means
Direction image signal, the vertical resolution (vertical scanning
Analog / digital conversion means for sampling with a higher resolution than the ( direction resolution) and converting to a digital signal,
The horizontal scanning lines of the video signal output from the image pickup means are aligned.
Raster address generation means for generating a dress ( raster address ) , position information of the measurement line set by the measurement line setting means, and the raster address from the raster address generation means are compared, and when the two match. Data relating to a digital video signal for one horizontal scanning line based on the timing at which the write signal is output, of the digital video signal output from the comparison means for outputting a write signal and the analog-digital conversion means. storage means for storing, on the basis of the data stored in the storage means, in which and a lead pitch calculation means for calculating the lead pitch.

According to a second aspect of the present invention, there is provided a lead shape inspection apparatus for an electronic component, wherein a two-dimensional image pickup means for picking up an image of the lead arrangement of the electronic component, a display means for displaying the lead arrangement picked up by the image pickup means, a measuring line setting means for setting a plurality of lead pitch measurement line on any horizontal <br/> scan lines on the display means, the horizontal scanning line direction of the video signal that will be output from the imaging means, the imaging means The analog-to-digital conversion means for sampling at a resolution higher than the vertical resolution ( resolution in the vertical scanning direction) and converting it into a digital signal, and the address ( raster address ) of the horizontal scanning line of the video signal output from the image pickup means. Raster address generating means for generating the position information of a plurality of measurement lines set by the measurement line setting means; And a digital image output from the analog-to-digital conversion unit, which compares the raster address from the target address generation unit with each other and outputs a write signal when the position information and the raster address match. Of the signals, storage means for storing data relating to digital video signals for a plurality of horizontal scanning lines based on the timing at which each write signal is output, and data for a plurality of scanning lines stored in the storage means And a lead pitch calculating means for calculating the lead pitch for each line based on the above.

[0009]

The operation of the invention described in claim 1 is as follows. When the lead arrangement of the electronic components imaged by the two-dimensional image pickup means is displayed on the display means, the measurement line setting means sets the lead pitch measurement line on an arbitrary horizontal scanning line whose lead pitch is to be measured. Raster address generating means, run horizontally Ru is output from the imaging means
The raster address (horizontal scanning line order) of the video signal in the scanning line direction is output. The comparison means compares the raster address that changes sequentially with the position information of the measurement line, and outputs a write signal when both match. On the other hand, the video signal in the horizontal scanning line direction that will be output from the imaging means, the analog-to-digital conversion means is sampled and converted into a digital video signal at a higher resolution than the vertical resolution of the image pickup means (resolution in the vertical scanning direction) It The storage means stores data related to the digital video signal for one horizontal scanning line based on the write signal. The data for one horizontal scanning line is along the set lead pitch measurement line. The lead pitch calculation means calculates the lead pitch along the measurement line based on the data stored in the storage means.

The operation of the invention described in claim 2 is as follows. The basic operation is similar to that of the first aspect of the invention. According to the present invention, a plurality of lead pitch measuring lines are set along arbitrary horizontal scanning lines, and lead pitches along the respective lines are calculated.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) FIG. 1 is a block diagram showing the schematic arrangement of a lead shape inspection apparatus for electronic parts according to the first embodiment. Similar to the conventional apparatus described above, the IC 1 to be inspected is placed on the inspection stage 3, and light is emitted substantially horizontally from a light source (not shown) along the gap between the package body 1a and the inspection stage 3. The light that has passed through the array of the leads 2 is guided to the CCD camera 13 via the reflection mirror 11 and the optical system 12. This CCD camera 13
Corresponds to the two-dimensional imaging means in the present invention.

The video signal output from the CCD camera 13 is given to the CRT 14 via the changeover switch SW, as well as to the binarization circuit 15 and the high speed A / D converter 16. The video signal binarized by the binarization circuit 15 is written in the frame memory 17A.
Related to the frame memory 17A is a measurement line display memory 17B. This measurement line display memory 17B
Stores a binary image of the lead pitch measuring line set based on the operation of the operation key 18 by the operator. The operation key 18 corresponds to the measurement line setting means in the present invention. The contents of both memories 17A and 17B are read synchronously and given to the CRT 14 via the switch SW.

The high-speed A / D converter 16 corresponds to the analog / digital conversion means in the present invention, and is the CCD camera 1
The video signal output from 3 is sampled at a resolution higher than the vertical resolution of the CCD camera 13 and converted into a digital signal. Specifically, the CCD camera 13 is usually
When a digital video image having the same vertical and horizontal resolution is obtained with 525 scanning lines in the vertical direction, the analog video signal output from the CCD camera 13 is sampled by a clock pulse of 12 MHz and converted into a digital signal. In this embodiment, in order to make the horizontal resolution higher than the vertical resolution, the analog video signal is sampled with a clock pulse of 48 MHz and converted into a digital signal, so that a digital video equivalent to about 2000 dots per scanning line is obtained. It is converted into a signal.

The digital video signal output from the high speed A / D converter 16 is supplied to a line video signal acquisition processing section 20 for acquiring the video signal of a designated one scanning line for lead pitch measurement. The line video signal acquisition processing unit 20 includes a line memory 21 for temporarily storing a digital video signal for one scanning line and a comparator 22 for binarizing the digital video signal read from the line memory 21. A shift register 23 that temporarily stores the output (binarized signal) of the comparator 22, a memory 24 in which the contents of the shift register 23 are written, and a comparator 25 that gives a write signal to the line memory 21.
A register 26 for giving the position information of the lead pitch measurement line to the comparator 25, a register 27 for giving a threshold value for the binarization to the comparator 22, and the like.

The raster address generation circuit 30 is a CCD
CR (not shown) for scanning control of the camera 13 and CRT 14
A horizontal synchronization signal HS and a vertical synchronization signal VS are given from the T controller. Raster address generation circuit 30
Has a counter for counting the horizontal synchronizing signal HS, and the count value is cleared by the vertical synchronizing signal VS. The raster address generation circuit 30 outputs the address (raster address) of the horizontal scanning line of the image projected on the CRT 14, and supplies this to the comparator 25 of the line image signal fetch processing unit 20.

The CPU 31 calculates the floating of the lead based on the binarized video signal of the lead arrangement written in the frame memory 17A, and determines the lead pitch based on the data for one scanning line written in the memory 24. Calculations are performed and values are set in the registers 26 and 27, respectively.

The raster address generating circuit 30 described above
Corresponds to the raster address generating means in the present invention, the comparator 25 corresponds to the comparing means in the present invention, the memory 24 corresponds to the storing means in the present invention, and the CPU 3
1 corresponds to the lead pitch calculating means in the present invention.

The operation of the above-described embodiment apparatus will be described below. When the operator operates the operation key 18 to set the switch SW on the frame memory 17A side, a binary image of the lead array of the IC1 is displayed on the CRT 14. The operator operates the operation key 18 while looking at the binarized image to appropriately set the binarization level (threshold value). CPU31, operation key 1
The threshold value of the binarization circuit 15 is changed according to the threshold value input from 8 and the set threshold value is written in the register 27.

Next, the operator operates the operation key 18 to set a measurement line for measuring the lead pitch on the CRT 14. The CPU 31 determines the measurement line display memory 17 based on the designation from the operation keys 18.
The binarized image of the measurement line is written in the designated address in B, and the position information of the horizontal scanning line in which the measurement line is set is written in the register 26. Figure 2 shows a CRT
14 shows the binarized image of the lead array portion superimposed and displayed on 14 and the set measurement line. Reference symbol L in the figure
Is the measurement line and RA is the raster address (positional information) of the measurement line L.

The above-mentioned binary level and measurement line L
After the setting is completed and the measurement start is instructed via the operation key 18, the binary image signal for one screen is taken in for the measurement of lead floating and the measurement line is measured for the lead pitch. The video signal for one line is captured.

The acquisition of the binarized video signal for one screen is as follows.
The image signal output from the CCD camera 13 is binarized by the binarizing circuit 15, and the binarized image signal is written in the frame memory 17A.

On the other hand, the video signal for one line for measuring the lead pitch is taken in as follows. First,
The video signal output from the CCD camera 13 is high-speed A /
After being sampled by the D converter 16 at a cycle of 48 MHz, it is converted into a digital signal. As a result, a video signal represented by 512 dots in the horizontal direction is usually converted into a high resolution digital video signal represented by pixels of about 2000 dots in the horizontal direction. This digital video signal is output to the line memory 21, but the line memory 21 does not write the input signal while the comparator 25 does not supply the write signal. The comparator 25 compares the raster address sequentially input from the raster address generation circuit 30 with the position information of the measurement line set in the register 26, and outputs a write signal to the line memory 21 when both match. As a result, the digital video signal for one scanning line along the measurement line is temporarily stored in the line memory 21.

When the acquisition of the binarized video signal for one screen into the frame memory 17A is completed, the line memory 21
The digital video signals for one scanning line are sequentially read out and supplied to the comparator 22. The comparator 22 compares the digital video signal with a threshold value set in the register 27, converts the digital video signal into a binarized video signal, and sends it to the shift register 23 in order. The binarized video signal for one scanning line stored in the shift register 23 is output in parallel from the shift register 23 and stored in the memory 24.

When the acquisition of the binarized video signal for one screen and the acquisition of the binarized video signal for one scanning line along the measurement line are completed as described above, the CPU
Reference numeral 31 calculates the floating of the lead based on the binarized video signal for one screen stored in the frame memory 17A. Specifically, as shown in FIG. 2A, this is performed by counting the number of pixels from the reference line O set according to the tip of the longest lead in the Y direction to the tip of each lead.
Further, the CPU 31 calculates the lead pitch along the measurement line based on the binarized video signal for one scanning line stored in the memory 24. Specifically, as shown in FIG. 2B, the lead pitch P is obtained by counting the number of pixels between the centers of the “L” level (corresponding to the lead) of the binarized video signal for one scanning line. To calculate. Here, the binarized video signal for one scanning line for lead pitch measurement is 1
Approximately 4 times the binarized video signal for the screen (dot number: 200
The lead pitch can be calculated with high accuracy because it is detected with the resolution equivalent to 0).

In the present embodiment, when measuring the bending amount of each lead 2, the operation line 18 is used to set the measurement line again to the side closer to the package body 1a (the line indicated by the reference symbol L'in FIG. 2). In the same manner as described above, the binarized video signal for one scanning line along the measurement line L ′ is fetched and the lead pitch P ′ along the measurement line L ′ is calculated. Then, the bending amount of each lead 2 can be measured by obtaining the difference (PP ′) between the lead pitches P and P ′ along the measurement lines L and L ′.

(Second Embodiment) In the first embodiment, CR is used.
Since only one measurement line can be set on the screen of T14, when calculating the bending amount of each lead 2, the measurement line is set a plurality of times as described above, and each time the measurement line is set along the line. It is necessary to capture and process the binarized video signal. On the other hand, in the second embodiment, two lead pitch measuring lines are simultaneously set on the screen of the CRT 14 so that the lead pitch along each line can be calculated by a single image capturing process. ing.

A schematic structure of the second embodiment is shown in FIG. Figure 1
Since the parts denoted by the same reference numerals as those of the above parts have the same configurations as those of the first embodiment, detailed description thereof will be omitted. The feature of this embodiment is that it is provided with two line video signal acquisition processing units 20A and 20B corresponding to two measurement lines. As shown in FIG. 4, when the operator operates the operation key 18, when the two measurement lines L1 and L2 are set on the binarized image of the lead arrangement portion displayed on the CRT 14, the CPU 31 performs the measurement. Line L
The raster address (position information) of 1 is set in the register 26A of the line video signal acquisition processing unit 20A, and the position information of the measurement line L2 is set in the register 26B (not shown) of the line video signal acquisition processing unit 20B. As a result, a high-resolution binarized video signal along the measurement line L1 is written in the memory 24A of the line video signal capture processing unit 20A by one image capture, and a high-resolution 2 image along the measurement line L2 is obtained. The binarized video signal is captured in the memory 24B (not shown) of the line video signal capture processor 20B. The CPU 31 calculates the lead pitch for each line based on the binarized video signals of the measurement lines L1 and L2 stored in the memories 24A and 24B, and calculates the difference between the lead pitches to bend the leads. The quantity can be measured.

When three or more lead pitch measuring lines are set, it is sufficient to provide a line video signal fetching processing section of the number corresponding to the measuring lines, and by doing so, one time image fetching can be arbitrarily performed. The lead pitch along each line of the number can be calculated with high accuracy.

In each of the above-described embodiments, the operator operates the operation key 18 to set the lead pitch measuring line on the screen of the CRT 14, but the present invention is not limited to this. For example, as shown in FIG. 5, the measurement line L is set at a position where the distance from the reference line O is, for example, 10% of the distance from the reference line O to the line Q along the edge of the package body 1a. As described above, if programmed in advance, it is possible to automatically set the measurement line L and calculate the lead pitch. Of course, when setting two or more measurement lines, it is possible to automate similarly.

Further, in each of the above-described embodiments, the case where the pitch of the leads arranged on one side of the flat package type IC is measured has been described as an example, but the shape of the leads arranged on the other side is measured. For inspection, IC1 18
The same measurement may be performed by rotating 0 degree. Also, IC1
When the shape inspection of the lead arrays on both sides of the lead array is performed simultaneously, a light source for irradiating each lead array from the inside is provided, and the light passing through each lead array is processed as in the first or second embodiment. It is also possible to perform shape inspection of each lead array at the same time by detecting with different devices. Similarly, a device such as the first and second embodiments is
If one is used, it is possible to simultaneously perform shape inspection of each lead group of so-called QFP (Quad Flat Package) in which the lead groups are derived from the four sides of the package body.

The present invention is not limited to the configuration of each of the above-described embodiments, but can be modified in various ways. For example, in the embodiment, the digital video signal for one scanning line along the lead pitch measurement line is temporarily stored in the line memory 21 and then binarized and stored in the memory 24. Without using the memory 21, the output signal of the high-speed A / D converter 16 is given to the comparator 22 to be binarized, and the binarized video signal is based on the coincidence signal (write signal) from the comparator 25, The memory 24 may be directly written.

[0033]

As is apparent from the above description, according to the invention described in claim 1, the lead pitch measuring line is accurately set at an arbitrary position of the image of the lead array displayed on the display means. Since the video signal for one horizontal scanning line along the measurement line is captured with high resolution to calculate the lead pitch, the lead pitch can be measured with high accuracy. Further, according to the present invention, unlike the conventional device, a dedicated optical system for measuring the lead pitch, a CCD line sensor, and the like are not required, so that the structure of the device is simplified accordingly.

Further, according to the invention of claim 2,
In addition to the effect of the invention described in claim 1, each lead pitch along a plurality of measurement lines can be measured by one image capture, so that the processing efficiency of the lead shape inspection apparatus is improved. You can Further, unlike the conventional device, there is no need to provide a mechanism for moving the CCD line sensor or to install a plurality of CCD line sensors, so that the structure of this kind of inspection device is simplified and realized at low cost. can do.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a first embodiment of an electronic component lead shape inspection apparatus according to the present invention.

FIG. 2 is a diagram for explaining the operation of the first embodiment device.

FIG. 3 is a block diagram showing a schematic configuration of a second embodiment of the present invention.

FIG. 4 is a diagram for explaining the operation of the second embodiment device.

FIG. 5 is a diagram for explaining a modified example of a method for setting a lead pitch measurement line.

FIG. 6 is a diagram showing a schematic configuration of a conventional device.

FIG. 7 is a diagram for explaining the operation of the conventional device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... IC (electronic part to be inspected) 1a ... Package body 2 ... Lead 3 ... Inspection stage 13 ... CCD camera (two-dimensional imaging means) 14 ... CRT (display means) 16 ... High-speed A / D converter (analog Digital conversion means 18 ... Operation key (measurement line setting means) 24 ... Memory (storage means) 25 ... Comparator (comparison means) 30 ... Raster address generation circuit (raster address generation means) 31 ... CPU (lead pitch calculation means)

Claims (2)

[Claims] 1. A two-dimensional image pickup means for picking up an image of the lead arrangement of an electronic component, a display means for displaying the lead arrangement picked up by the image pickup means, and a lead pitch measuring line on an arbitrary horizontal scanning line of the display means. a measuring line setting means for setting a horizontal scanning line direction of the video signal that will be output from the imaging means, degradation of vertical resolution (the vertical scanning direction of said image pickup means
The analog-to-digital conversion means for sampling with a higher resolution than that of the above ) and converting it into a digital signal, and the horizontal scanning line of the video signal output from the imaging means.
Raster address generating means for generating a dress ( raster address ) , position information of the measurement line set by the measurement line setting means, and the raster address from the raster address generating means are compared, and when the two match. Comparing means for outputting a write signal, and data related to the digital video signal for one horizontal scanning line based on the timing at which the write signal is output among the digital video signals output from the analog / digital converting means. storage means for storing, based on the data stored in the storage means, the read shape inspection apparatus for electronic components, characterized by comprising a lead pitch calculation means for calculating the lead pitch. 2. A two-dimensional image pickup means for picking up an image of the lead arrangement of an electronic component, a display means for displaying the lead arrangement picked up by the image pickup means, and a plurality of lead pitches on an arbitrary horizontal scanning line of the display means. a measuring line setting means for setting the measuring line, a horizontal scanning line direction of the video signal that will be output from the imaging means, degradation of vertical resolution (the vertical scanning direction of said image pickup means
The analog-to-digital conversion means for sampling with a higher resolution than that of the above ) and converting it into a digital signal, and the horizontal scanning line of the video signal output from the imaging means.
Raster address generating means for generating a dress (raster address ) , position information of a plurality of measurement lines set by the measurement line setting means, and a raster address from the raster address generating means are respectively compared, Comparing means for outputting a write signal when the position information and the raster address match each other, and based on the timing at which each write signal is output among the digital video signals output from the analog / digital converting means. , calculating a storage means for storing data associated with the digital video signals of a plurality of horizontal scan lines, based <br/> data in multiple scan line stored in the storage means, the lead pitch of each line And a lead pitch calculation means for performing lead shape detection of an electronic component. Inspection device.