JPH05280932A - Measuring device of pin position of electronic component - Google Patents

Abstract

PURPOSE:To measure positions of all pins of an electronic component correctly by making a search for the pin positions from the package side on an image obtained by picking up the image of the electronic component. CONSTITUTION:A reference point G is set on an image part of a package of a binary image obtained by picking up the image of an electronic component. A measuring line L being parallel to the axis X is set, while it is shifted in the direction of getting away from the reference point G, and measurement of runs on the measuring line L is executed. When the number of runs on the measuring line L coincides with the number of pins of the electronic component, the measuring line L is judged to have reached the position of the base end of the pin and the position of the measuring line and the central position of each run at that time are made the position of the base end of each pin. Then, the position of the fore end of the pin is searched for by tracing the image part of the pin from the position of the base end of each pin by using a gray image of the electronic component.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic component, such as an IC or QFP chip, in which a pin protrudes from a package having a rectangular planar shape, and uses image processing technology to determine whether the pin length is good or not. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a component inspection device for inspecting bends and the like, and in particular, the present invention relates to a pin position measuring device for electronic components applied to measure the base end position and tip position of a pin required for this type of inspection. Regarding

[0002]

2. Description of the Related Art A conventional pin position measuring apparatus of this type uses a predetermined grayscale image obtained by capturing an image of an electronic component to be inspected.
After the binarization processing is performed with the binarization threshold value, the binary image is scanned from the start end of the image to measure the tip position of the pin.

[0003]

However, with such a pin position measuring device, it is difficult to properly measure the tip position of the pin because the grayscale image cannot be properly binarized due to the small diameter of the pin. Is. In particular, when the inspection target is imaged under reflected illumination, the reflection state of the illumination light differs for each pin, so that an appropriate binary image cannot be obtained and the tip positions of all pins cannot be measured correctly.

The present invention has been made in view of the above problem, and by searching for pin positions from the package side on an image obtained by picking up an image of an electronic component, all pins of the electronic component can be searched. An object of the present invention is to provide a pin position measuring device for electronic parts, which can measure the position correctly.

[0005]

A pin position measuring device according to the present invention is for measuring a base end position of a pin, and images an electronic component in which the pin projects from a package having a rectangular planar shape. Image generating means for generating a two-dimensional image of an electronic component in which one side of the image portion of the package is parallel to the reference axis of the image, storage means for storing the number of pins of the electronic component, and measurement parallel to the reference axis. Measuring means for measuring the run on the measuring line by setting the line while moving in the direction away from the reference point defined on the image part of the package, and the number of runs on each measuring line measured by the measuring means. And a determination unit that determines the position of the measurement line with respect to the two-dimensional image by comparing the number of pins stored in the storage unit, and the measurement line reaches the image portion of the pin by the determination unit. When it is determined that the one in which and a calculating means for calculating a base end position of the pin from the position information of each run.

In the pin position measuring apparatus according to the invention of claim 2, the number of runs on the measurement line measured by the measuring means is equal to the number of pins stored in the storing means under the reflected illumination. When they match, it is determined that the measurement line has reached the image portion of the pin, and under transmitted illumination, the number of runs on the measurement line measured by the measuring unit is added to the number of pins stored in the storage unit. When it matches the value, it is determined that the measurement line has reached the image portion of the pin.

In the pin position measuring device according to the invention of claim 3, in order to measure the base end position of the pin, the structure described in claim 1 is used, in which the base end position of the pin calculated by the calculating means is used. A search means for tracking the pin image portion of the grayscale image of the electronic component and searching for the tip position of the pin image portion is added.

[0008]

[Function] Since the base end position of the pin is determined by the run measurement from the package side toward the pin on the image obtained by picking up the image of the electronic component, the base end position of the pin can be easily and properly adjusted. It is possible to measure, and it is effective for measuring the tip position of the pin.

According to the second aspect of the present invention, the base end position of the pin can be measured regardless of whether the illumination is reflected illumination or transmitted illumination, simply by changing the data for comparing the number of runs.

In the third aspect, the base end position of the pin is obtained from the package side in the direction of the pin by the run measurement, and then the image part of the pin is determined from the base end position of the pin by using the grayscale image of the electronic component. Since the tip position of the pin is searched by tracing, the tip position of the pin can be easily and properly measured.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the overall construction of a parts inspection system incorporating the pin position measuring device of the present invention. The component inspection system of the illustrated example is composed of a robot 3, a television camera 7, an image processing device 8 and the like, and when a tray 2 on which a plurality of electronic components 1 such as IC chips are placed is supplied to an inspection position. The hand part 4 of the robot 3 picks up the electronic components 1 on the tray 2 one by one and places them on the supporting substrate 5 at a predetermined position and in a predetermined posture. The TV camera 7 picks up an image. In this embodiment, the surface of the substrate 5 is set to an intermediate color of lightness (for example, gray).

As shown in FIGS. 2 and 3, the electronic component 1 has a structure in which a predetermined number (the same number in this example) of pins 11 are projected from both side surfaces of a package 10 having a rectangular planar shape. is there. The surface of the package 10 is black, and each pin 11 has a metallic color. When the electronic component 1 is illuminated with light from above and observed from directly above, the package 10 is observed to be black and each pin 11 is observed to be white. ..

The television camera 7 uses, for example, a CCD as an image pickup device, and a two-dimensional grayscale image obtained by picking up an image of the electronic component 1 from above is an image processing device 8.
Is output to. In FIG. 1, 9 is a video monitor provided in the image processing apparatus 8.

FIG. 4 shows a circuit configuration of the image processing device 8, which is an A / D converter 21, a binarization circuit 22, two image memories 23 and 24, a display controller 25, and a D / A. A converter 26 is included.

The A / D converter 21 converts a video signal input from the television camera 7 into a digital grayscale image signal. The density of each pixel forming the grayscale image is 0 to 2
The grayscale image is given in 55 density gradations, and this grayscale image is stored in one of the image memories 23 on a pixel-by-pixel basis.

The binarization circuit 22 is composed of an LUT (look-up table), inputs a grayscale image signal from the A / D converter 21, and performs a binarization process with a predetermined binarization threshold value. This binary image is stored in the other image memory 24 on a pixel-by-pixel basis.

FIG. 5 shows an example of setting the binarization threshold value in this embodiment. The first binarization threshold TH1 is a density level (density gradation of 25
5) and the density level (the density gradation is K) of the image portion of the support substrate 5 is set at an intermediate position, and the grayscale image of the electronic component 1 is binarized by the binarization threshold TH1. Then, as shown in FIG. 6, the image portion 1 of the package 10 is
0'is a black pixel area (indicated by diagonal lines in the figure), the other image portion is binarized into a white pixel area, and the image portion 10 'of the package.
A binary image 31 whose sides are parallel to the X axis and the Y axis is obtained. The binary image 31 of FIG. 6 is used to measure the center of gravity of the image portion 10 'of the package, that is, the reference point G described later.

The second binarization threshold value TH2 is defined by the pin 11 and the density level (density gradation K) of the image portion of the supporting substrate 5.
Is set at an intermediate position with respect to the density level of the image portion 11 '(the density gradation is 0).
When the grayscale image of the electronic component 1 is binarized with, the image portion 11 'of the pin 11 is in the white pixel area and the other image portion is in the black pixel area (indicated by diagonal lines in the figure) as shown in FIG. Valued. The binary image 32 shown in FIG. 7 is used to measure the base end position of the pin 11.

Returning to FIG. 4, the display control unit 25 selects the grayscale image or the binary image and outputs it to the D / A converter 26, and the D / A converter 26 converts the input signal into an analog amount. And output to the video monitor 9.

The image processing device 8 includes a CPU 27 which is a main body of control and calculation, and a ROM 28 and a RAM 29 are connected to the CPU 27 via a bus 30. Further, the bus 30 includes a binarization circuit 22, image memories 23, 2
4, the display controller 25 is also connected. The ROM 28 stores the control procedure of the CPU 27 related to the pin position measurement in a program, and the RAM 28 stores various data necessary for the CPU 27 to execute the control procedure, for example, the pin 1
The number N of 1 or the like is written.

The CPU 27 decodes and executes the program in the ROM 28 and executes various calculations and controls relating to pin position measurement while reading and writing data from and in the RAM 29. Further, the CPU 27 outputs the data for binarizing the grayscale image signal by using the binarization threshold values TH1 and TH2.
Write to the LUT of the digitization circuit 22.

FIG. 8 shows a control procedure for measuring the base end position of the pin 11 by the CPU 27 in step 1 (indicated by "ST1" in the figure) to step 11. First, when the electronic component 1 to be inspected is placed on the support substrate 5 at the start of the figure, the television camera 7 takes an image of the electronic component 1 from the upper side under reflective illumination, and the image signal thereof is an image processing apparatus. 8 is taken in.

In the image processing device 8, the A / D converter 21 converts the video signal into a grayscale image signal having a digily amount, and the grayscale image signal is stored in one image memory 23. Further, the grayscale image signal is supplied to the binarization circuit 22, binarized by the first binarization threshold value TH1, and the binarized image 31 is obtained.
(Shown in FIG. 6) is stored in the other image memory 24.

Next, in step 1, the CPU 27 uses the binary image 31 in the image memory 24 to determine the image portion 1 of the package.
The center of gravity position of 0'is calculated as a reference point G, and this reference point G
The Y-coordinate value Y _G is stored in the RAM 29. The reference point G is not limited to the position of the center of gravity, and may be the center point of the image, for example, as long as it is a point on the image portion 10 'of the package.

Next, the CPU 27 outputs the grayscale image to the second image.
2 data to be binarized with the threshold value TH2
After writing to the LUT of the digitization circuit 22, the image memory 23
By outputting a more grayscale image signal and passing it through the binarization circuit 22, the second binarization threshold TH2 becomes 2
A binarized binary image 32 (shown in FIG. 7) is generated and stored in the image memory 24 (step 2).

Next, in step 3, the Y coordinate value Y _G of the reference point G is incremented by 1 in the Y coordinate measurement area set in the RAM 29, but the count value Y _A is set. This measurement region has one side (see FIG. 7) in the binary image 32 shown in FIG.
It is for measuring the Y coordinate value of the base end position of the image portion 11 'of the pin on the upper side.

In the next step 4, the CPU 27 sets a measurement line L parallel to the X axis at the Y coordinate position corresponding to the count value Y _A on the binary image 32, and runs measurement on this measurement line L. Then, the number n of runs in the white pixel area is counted.

In the next step 5, it is judged whether or not the number n of runs is equal to the number N of pins on one side of the electronic component 1, and if the judgment is "NO", step 3 Then, the count value Y _A is incremented and the same run measurement is performed (step 4). The number N of pins is stored in advance in a predetermined area of the RAM 29.

As a result of repeatedly executing the same procedure, when the position of the measurement line L reaches the base end position of the image portion 11 'of the pin, the number N of pins on this measurement line L is determined.
The number n of runs of the number corresponding to is measured.
As a result, the determination in step 5 becomes "YES" and the process proceeds to step 6, and the CPU 27 determines the X coordinate value X of the center point of each run from the X coordinate values of the start end position and the end position of each run.
_i (where i = 1, 2, ..., N) is calculated and stored in the RAM 29 together with the count value Y _A at that time.

The following steps 7 to 11 are Y at the base position of the image portion 11 'of the pin on the other side (lower side in FIG. 7).
This is a control procedure for measuring the coordinate value, and by performing the same procedure as above while decrementing the count value Y _B set in the RAM 29, the measurement line L is the image portion 11 ′ of the pin on the other side. X coordinate value X _j (where j = 1, 2, ...) Of the center point of each run when reaching the base position of
..., n) is calculated.

FIG. 9 shows each pin 11 by the CPU 27.
The control procedure for measuring the tip position of is shown in step 1 (indicated by "ST1" in the figure) to step 11. First, in step 1 of the figure, "1" is set as the initial value of the count value i in the count area set in the RAM 29. This count value i indicates the number of each run for the pin row on one side, and the X value set in the RAM 29 in the next step 2
Coordinates (X _i , Y _A ) of the center point of the i-th (i = 1) run are set as measurement values X _c (i) and Y _c (i) in the Y coordinate measurement area.

In the next step 3, the coordinates (X _i ,
The image memory 23 is accessed for a predetermined pixel adjacent in the search direction (in this case, the positive direction of the Y-axis) with the pixel at the position of Y _A ) as the pixel of interest, and the respective densities are read.

In FIG. 10, 33 is the coordinate (X _i ,
When the target pixel 33 location Y _A), where the coordinate (X _i -1, the concentration of Y _A +1) of the position of the pixel 34 a1
And the density a of the pixel 35 at the position of coordinates (X _i , Y _A +1)
2 and the density a3 of the pixel 36 at the position of the coordinates (X _i +1, Y _A +1) are read.

In the next step 4, the CPU 27 determines whether or not the densities a1, a2 and a3 of the adjacent pixels 34 to 36 are all the same as the densities K of the image portions of the supporting substrate 5, and the determination is made. Is "NO", the process proceeds to step 5, where the densities a1, a2 and a3 of the adjacent pixels 34 to 35 are compared, the pixel having the minimum density is selected and set as the next pixel of interest 33, and the measurement is performed. The values X _c (i) and Y _c (i) are rewritten to the X coordinate value and the Y coordinate value of the pixel (step 6). In this case, when there are a plurality of pixels having the minimum density, it is determined in advance which position of the pixel is to be the next pixel of interest.

As a result of repeating the same procedure, when the densities a1, a2 and a3 of the adjacent pixels 34 to 36 are all the same as the densities K of the image portion of the supporting substrate 5, the position of the pixel of interest 33 is a pin image. When it is judged that the tip position of the portion 11 'has been reached, the process proceeds from step 4 to step 7,
PU27 is X coordinate at that time as the X coordinate of the tip position of the pin
_{Let c} (i) be the Y coordinate and _Yc (i) be RA
It is stored in a predetermined area of M29.

In the next step 8, it is judged whether or not the tip positions have been searched for all the pins on one side. In this case, since the judgment is "NO", the count value i is calculated in the next step 9. Is incremented to "2" and step 2
Returning to, the coordinates (X _i , X _i ,) of the center point of the i-th (i = 2) run are set in the measurement area of the XY coordinate values set in the RAM 29.
Y _A) the measured value X _c (i), is set as Y _c (i), to perform the same procedure follows.

When the tip positions of all the pins are searched, the determination in step 8 becomes "YES" and the process proceeds to step 9, and then the X coordinate value of the tip position of the image portion 11 'of the pin on the other side. Perform a search for X _D (j) and Y coordinate value Y _D (j). In this search process, as shown in FIG. 11A, when 33 is the pixel of interest 33 at the position of coordinates (X _j , Y _B ), the pixel at the position of coordinates (X _j -1, Y _B -1) is displayed. read the concentration a1 of 37, the coordinates (X _j, Y _B -1) and concentration a2 pixel 38 location, and the concentration a3 coordinates _{(X j + 1, Y B} -1) of the position of the pixel 39, The next target pixel 33 will be determined.

FIG. 11B shows the position of the adjacent pixel with respect to the pixel of interest 33 when the negative direction of the X axis is the search direction, and FIG. 11C shows the case where the positive direction of the X axis is the search direction. The positions of the adjacent pixels with respect to the pixel of interest 33 are shown, and the search procedure is the same as above, and the description thereof is omitted here.

The above embodiment is an example of an apparatus for measuring the base end position and the tip end position of a pin from an image obtained by picking up an image of the electronic component 1 under reflected illumination. When the base position of the pin is measured from the image obtained by imaging, when the number n of runs in the white pixel area on the measurement line L matches the value obtained by adding 1 to the number N of pins, It is judged that the measurement line L has reached the base end position of the pin.

[0040]

As described above, according to the present invention, the base position of the pin is determined by the run measurement from the package side toward the pin on the image obtained by picking up the image of the electronic component. Can easily and properly measure the base position of
From this measurement result, the tip position of the pin can be easily measured.

The invention according to claim 2 judges that the measurement line has reached the image portion of the pin when the number of runs on the measurement line matches the number of pins under the reflection illumination, and under the transmission illumination, The number of runs on the measurement line is 1 for the number of pins
When it agrees with the added value, it is determined that the measurement line has reached the image part of the pin.Therefore, simply changing the data that compares the number of runs, regardless of whether it is reflective illumination or transmissive illumination, The base position can be measured.

In the third aspect, the base end position of the pin is obtained from the package side in the direction of the pin by run measurement, and then the grayscale image portion of the pin is traced from the base end position of the pin to detect the tip end position of the pin. Therefore, the tip position of the pin can be easily and properly measured.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an overall configuration of a component inspection system using a pin position measuring device of the present invention.

FIG. 2 is a plan view showing an electronic component placed on a support substrate.

FIG. 3 is a front view showing an electronic component placed on a support substrate.

FIG. 4 is a block diagram showing a circuit configuration of an image processing apparatus.

FIG. 5 is an explanatory diagram showing an example of setting a binarization threshold value.

FIG. 6 is an explanatory diagram showing a binary image of an electronic component binarized by a first binarization threshold value.

FIG. 7 is an explanatory view showing a binary image of an electronic component binarized by a first binarization threshold and a principle of measuring a base end position of a pin.

FIG. 8 is a flowchart showing a procedure for measuring a base end position of a pin.

FIG. 9 is a flowchart showing a procedure for measuring the tip position of a pin.

FIG. 10 is an explanatory diagram showing a positional relationship between a pixel of interest and an adjacent pixel for searching a pin tip position.

FIG. 11 is an explanatory diagram showing a positional relationship between a pixel of interest and an adjacent pixel for searching for a pin tip position.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electronic component 7 Television camera 8 Image processing device 7 Working device 10 Package 11 pin 22 Binarization circuit 27 CPU 28 ROM 29 RAM

Claims (3)

[Claims] 1. An image generating means for capturing an image of an electronic component having pins protruding from a package having a rectangular planar shape and generating a two-dimensional image of the electronic component in which one side of an image portion of the package is parallel to a reference axis of the image. A storage unit that stores the number of pins of the electronic component and a measurement line that is parallel to the reference axis while being moved in a direction away from a reference point defined on the image portion of the package to set a run measurement on the measurement line. And a determination unit that determines the position of the measurement line with respect to the two-dimensional image by comparing the number of runs on each measurement line measured by the measurement unit with the number of pins stored in the storage unit. An electronic device comprising: a calculating unit that calculates the base end position of the pin from position information of each run when the determining unit determines that the measurement line has reached the image portion of the pin. Goods pin position measurement device. 2. The determination means, when the number of runs on the measurement line measured by the measurement means is equal to the number of pins stored in the storage means under reflected illumination, the measurement line is an image portion of the pins. When the number of runs on the measurement line measured by the measuring means is equal to the value obtained by adding 1 to the number of pins stored in the storage means under transmitted illumination, the measurement line is The electronic device pin position measuring device according to claim 1, wherein it is determined that the image position has been reached. 3. An image generating means for imaging an electronic component having pins protruding from a package having a rectangular planar shape and generating a two-dimensional image of the electronic component in which one side of an image portion of the package is parallel to a reference axis of the image. A storage unit that stores the number of pins of the electronic component and a measurement line that is parallel to the reference axis while being moved in a direction away from a reference point defined on the image portion of the package to set a run measurement on the measurement line. And a discriminating means for discriminating the set position of the measuring line with respect to the two-dimensional image by comparing the number of runs on each measuring line measured by the measuring means with the number of pins stored in the storing means. Calculating means for calculating the base end position of the pin from the position information of each run when it is judged by the judging means that the measurement line has reached the image portion of the pin; Pin position measuring device for an electronic component comprising a search means for searching a track and the pin tip position the image portion of the pin of an electronic component grayscale image from a proximal position of the pin calculated by.