JPH10132515A - Pattern inspection device and inspection method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily inspect the arrangement pattern of lead terminals without damaging them by collating a terminal arrangement image with a gauge pattern to judge the quality of the arrangement, and correcting a defective terminal. SOLUTION: The output signal of an image pickup device 31 in which the terminal arrangement of a body 6 to be inspected is photographed and digitized by an A/D converting circuit 32, and the arrangement patter of terminals taken as a terminal arrangement image is stared in a frame memory 33. An image processing system 4 has a frame memory 41, a pattern collating circuit 42, a terminal area setting circuit 43, and a gauge position setting circuit 44, and the occupying area of each lead terminal is detected from the terminal arrangement image to set the hole position of a gauge pattern. A pattern collating system 5 has a judging circuit 51, a judgment result output circuit 52, and a gauge position correcting circuit 53, and the judging circuit 51 collates the occupying area of each lead terminal with the gauge pattern to judge the quantity of arrangement of the lead terminal. The lead terminal which is judged not to be insertable by the gauge position correcting circuit 53 is corrected according to a prescribed procedure.

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 an arrangement pattern of a plurality of lead terminals for a semiconductor device, a relay, a connector and the like, and more particularly to a pattern capable of easily inspecting an arrangement pattern without damaging the lead terminals. The present invention relates to an inspection device and an inspection method.

2. Description of the Related Art A semiconductor device, a relay, a connector, and the like mounted on a printed circuit board have a plurality of lead terminals arranged at a predetermined pitch. Components cannot be mounted on printed circuit boards.

As a means for extracting such electronic components, an arrangement pattern of lead terminals is inspected before mounting on a printed circuit board. When inspecting the arrangement pattern, a mechanical external force is applied to each lead terminal. In some cases, implementation becomes impossible due to deformation.

Therefore, there is a demand for the development of a pattern inspection apparatus capable of easily inspecting an array pattern without damaging lead terminals.

[0005]

2. Description of the Related Art FIG. 6 is a perspective view showing a conventional pitch gauge, and FIG. 7 is a view for explaining a conventional pattern inspection method.

In FIG. 6, an electronic component 1 such as a semiconductor device, a relay or a connector has a plurality of lead terminals 11 arranged at a predetermined pitch. It becomes impossible to mount the component 1 on a printed circuit board.

Therefore, as shown in the drawing, an inspection is performed using a pitch gauge 2 having a gauge hole 21 at a position corresponding to each lead terminal 11, and the electronic component 1 and the pitch gauge 2 are held by hand and all the leads are held. The electronic component 1 in which the terminal 11 can be fitted into the gauge hole 21 is a non-defective product.

Incidentally, as shown in FIG. 7A, even if the arrangement pitch of the lead terminals 11 deviates from a predetermined pitch, the gauge holes 21 are not formed.
Is finely adjusted, and when all the lead terminals 11 can be inserted into the gauge holes 21 as shown in FIG. 7 (b), the terminal arrangement of the electronic component 1 is determined to be good.

[0009]

However, the conventional pattern inspection method is based on the premise that an electronic component and a pitch gauge are inspected while being held in a hand, and the pattern inspection by hand is simply replaced with the pattern inspection by a machine. However, automation of pattern inspection cannot be realized.

For example, when the lead terminals deviate from a predetermined arrangement pitch, the positions of the electronic component and the pitch gauge are finely adjusted. However, unlike the pattern inspection by hand, the position of the pitch gauge is determined by the mechanical pattern inspection. It is difficult to make subtle corrections.

As a result, the operation of correcting the position of the pitch gauge and the operation of inserting the lead terminal into the gauge hole are repeated by trial and error, until the pitch gauge is fixed at a position suitable for insertion of the lead terminal. There was a problem that the lead terminals were damaged during the operation.

An object of the present invention is to provide a pattern inspection apparatus which can easily inspect an array pattern without damaging lead terminals.

[0013]

FIG. 1 is a block diagram showing a pattern inspection apparatus according to the present invention. The same object is denoted by the same symbol throughout the drawings.

The above-mentioned problems are caused by the image input system 3 in which the arrangement pattern of the lead terminals is converted into a digital signal and taken in as a terminal arrangement image, the area occupied by each lead terminal is detected from the terminal arrangement image, and the hole position of the gauge pattern is set. And a pattern matching system 5 for comparing and matching the terminal arrangement image with the gauge pattern.
Is an imaging device 31 on which an arrangement pattern of lead terminals is imaged.
An analog-to-digital conversion circuit 32 for converting an output signal of the imaging device 31 into a digital signal, and a first frame memory 33 for storing a digitally arranged terminal array image. A second frame memory 41 in which the reference pattern of the arrangement is stored; a pattern matching circuit 42 for detecting the center position of each lead terminal from the terminal arrangement image and the reference pattern; A terminal area setting circuit 43 for setting an occupied area of the lead terminal based on the terminal shape, and a gauge position setting circuit 44 for setting a hole position of the gauge pattern in accordance with the terminal arrangement image. The occupied area of at least one lead terminal is determined by comparing the occupied area of the lead terminal with the hole position of the gauge pattern and determining whether the arrangement of the lead terminals is good or not. This is achieved by the pattern inspection apparatus of the present invention including a gauge position correction circuit 53 that corrects the position of the gauge pattern when the area deviates from the hole position of the gauge pattern.

[0015] An image input system in which the arrangement pattern of the lead terminals is imaged and captured as a terminal arrangement image in this manner,
The occupied area of each lead terminal is detected from the terminal arrangement image,
And the image processing system in which the hole position of the gauge pattern is set, and a pattern matching system in which the terminal array image and the gauge pattern are compared and matched, and the pattern of the present invention in which the arrangement of the lead terminals is determined is The lead terminal can be checked against the gauge pattern without directly contacting the lead terminal, and damage to the lead terminal can be eliminated.

That is, it is possible to realize a pattern inspection apparatus capable of easily inspecting an array pattern without damaging lead terminals.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 2 is a schematic diagram showing a terminal area setting method, FIG. 3 is a schematic diagram showing a gauge position setting method, FIG. 4 is a schematic diagram showing a method of judging the quality of the lead terminal arrangement, and FIG. 5 is a schematic diagram showing a gauge position correcting method. It is.

The pattern inspection apparatus according to the present invention comprises an image input system 3, an image processing system 4, and a pattern matching system 5 as shown in FIG.
The image input system 3 includes an imaging device 31 for imaging the object 6 to be inspected, an analog-to-digital conversion circuit 32, and a first frame memory 33.

That is, the output signal of the image pickup device 31 that has picked up the terminal arrangement of the device 6 to be inspected is digitized by the analog-to-digital conversion circuit 32, and the terminal arrangement pattern captured as a digital signalized terminal arrangement image is the first pattern. It is stored in one frame memory 33.

Hereinafter, the configurations of the image processing system and the pattern matching system and the operation of each circuit will be described in detail with reference to the accompanying drawings. In each description, n attached to various symbols is all lead terminals. Is an integer starting from 1 corresponding to the number.

The image processing system 4 includes a second frame memory 41, a pattern matching circuit 42, a terminal area setting circuit 43, and a gauge position setting circuit 44. The occupied area of each lead terminal is determined from the captured terminal arrangement image. The hole position of the gauge pattern is detected and set.

That is, the second frame memory 41 stores a reference pattern indicating the terminal arrangement of the lead terminals of the various devices 6 to be inspected. The center position _Pn of each lead terminal is detected as shown in FIG.

The terminal area setting circuit 43 stores the reference four corner positions C _a , C c of the corresponding lead terminals registered in advance as shown in FIG.
_b , C _c , and C _d are combined with the center position to occupy areas C _an , C _an of each lead terminal as shown in FIG.
_bn, C _cn, to set the C _dn.

FIG. 3 (b) shows the gauge position setting circuit 44.
The gage patterns corresponding to the reference patterns are previously registered as shown, the center G ₁ of the center position, for example P ₁ and the gauge hole of the lead terminals as a reference to set the position of the gage patterns to overlap.

The pattern matching system 5 includes a judgment circuit 51 for judging the arrangement of the lead terminals, a judgment result output circuit 52, and a gauge position correction circuit 53. The judgment circuit 51 compares and compares the occupied area of each lead terminal with the gauge pattern. Then, the quality of the arrangement of the lead terminals is determined.

That is, from the center _{Gn of} the gauge hole to the lead terminal 4
Distances D _an , D _bn , to the corner positions C _an , C _bn , C _cn , C _dn
D _cn , D _dn are calculated, and D _an , D _bn ,
D _cn, determined as non-defective is smaller than or R _g D _dn are all equal to the gauge hole radius R _g.

As shown in FIG. 4B, the distances D _an , D _bn ,
If at least one of D _cn and D _dn is larger than the radius R _g , the fitting cannot be performed. If it is determined that at least one lead terminal cannot be fitted, the position of the gauge pattern is determined by the following means. Correction is performed.

The distance gauge position correcting circuit 53 fitted挿不possible and the center position P _n of the determined lead terminals with the center G _n of the corresponding gauge hole, _{i.e., B = | P n -G n} | , respectively The calculated lead terminal having the largest displacement B from the center _{Gn of the} gauge hole is selected.

As shown in FIG. 5 (a), when a counterclockwise angle formed by a vector including G _n and P _n and an X coordinate axis passing through G _n is θ, a lead terminal outside the circumference of the gauge hole. The amount of correction is calculated by determining the intersection of the line passing through the corner and parallel to the vector and the gauge hole.

That is, _assuming that the intersection of a line passing through the corner of the lead terminal outside the circumference of the gauge hole and parallel to the vector and the circumference of the gauge hole is X, the corrected center _{Gn '} of the gauge hole is the vector It is located above and the correction amount is equal to the length of the vector connecting the corner of the lead terminal and X.

As shown in FIG. 5B, when 0 ≦ θ <90, the vector G _n · G _{n '} = vector X · C _bn indicating the gauge pattern correction amount, and as shown in FIG. If ≤θ <180, a vector G _n · G _{n '} indicating the gauge pattern correction amount
= Vector X · C _an .

If 180 ≦ θ <270 as shown in FIG. 5 (d), the vector G _n · G _{n '} = vector X · C _cn indicating the gauge pattern correction amount, and 270 ≦ θ as shown in FIG. 5 (e). <360
Now, a vector G _n · G _{n '} indicating the correction amount of the gauge pattern
= Vector X · C _dn .

The gauge position correction circuit 53 is provided with a gauge hole center _Gn.
For the lead terminal with the largest displacement B from
The above vectors X · C _bn , X · C _an , X · C _cn , X · C _dn
The position of the gauge pattern is set based on the correction amount obtained by calculating.

The vectors X · C _bn , X · C _an , X · C _cn ,
Based on the gauge position correction amount obtained by calculating X · C _dn , the gauge position correction circuit 53 sets the corrected position of the gauge pattern, and the determination circuit 51 determines whether or not the arrangement of the lead terminals is good.

In the above embodiment, the pattern matching circuit compares the terminal arrangement image with the reference pattern to determine the center position P of the lead terminal.
_{Although n} is detected, the image processing system may include a projection circuit or a center of gravity detection circuit and may directly detect the center position of the lead terminal from the terminal array image.

For example, the projection circuit can detect the center position _Pn of each lead terminal from the projection width of the terminal arrangement image in the X-axis and Y-axis directions. Find the center of gravity and find the center position P
_n can be detected.

For example, a display signal is output from the determination result output circuit 52 based on the determination result of the arrangement of the lead terminals in the determination circuit 51, and when it is determined that the product is non-defective, an LED or the like indicating the non-defective product is turned on to determine that the product is defective. If so, an LED indicating a defective product is turned on.

The pattern inspection method according to the present invention is applied to, for example, an insert machine in which various electronic components are mounted on a printed board, and the position of the printed board or the electronic component is determined based on a signal output from the determination result output circuit 52. Can also be corrected.

As described above, an image input system in which the arrangement pattern of the lead terminals is imaged and captured as a terminal arrangement image,
The occupied area of each lead terminal is detected from the terminal arrangement image,
And the image processing system in which the hole position of the gauge pattern is set, and a pattern matching system in which the terminal array image and the gauge pattern are compared and matched, and the pattern of the present invention in which the arrangement of the lead terminals is determined is The lead terminal can be checked against the gauge pattern without directly contacting the lead terminal, and damage to the lead terminal can be eliminated.

That is, it is possible to realize a pattern inspection apparatus capable of easily inspecting an array pattern without damaging the lead terminals.

[0041]

As described above, according to the present invention, it is possible to provide a pattern inspection apparatus which can easily inspect an array pattern without damaging lead terminals.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a pattern inspection apparatus according to the present invention.

FIG. 2 is a schematic diagram showing a terminal area setting method.

FIG. 3 is a schematic diagram showing a gauge position setting method.

FIG. 4 is a schematic diagram showing a method for determining the quality of a lead terminal array.

FIG. 5 is a schematic diagram showing a gauge position correction method.

FIG. 6 is a perspective view showing a conventional pitch gauge.

FIG. 7 is a diagram illustrating a conventional pattern inspection method.

[Explanation of symbols]

3 Image input system 4 Image processing system 5 Pattern matching system 6 Inspection object 31 Imaging device 32 Analog-to-digital converter 33 Frame memory 41 Frame memory 42 Pattern matching circuit 43 Terminal area setting circuit 44 Gauge position setting circuit 51 Judgment circuit 52 Judgment result Output circuit 53 gauge position correction circuit

Claims (3)

[Claims] 1. An image input system, an image processing system, and a pattern matching system, the image input system comprising: an imaging device for imaging an arrangement pattern of the lead terminals; and an output signal of the imaging device being a digital signal. An analog-to-digital conversion circuit, and a first frame memory storing the digitally converted terminal array image, wherein the image processing system includes a second frame storing a terminal array reference pattern. A memory, a pattern matching circuit for detecting a center position of each lead terminal from the terminal arrangement image and the reference pattern, and an occupied area of the lead terminal based on the center position of each lead terminal and a terminal shape registered in advance. And a gage position setting circuit for setting a hole position of a gage pattern in accordance with the terminal arrangement image. The occupied area and the hole position of the gauge pattern are compared and collated, and a determination circuit for determining whether the arrangement of the lead terminals is good or not, and when the occupied area of at least one lead terminal deviates from the hole position of the gauge pattern, A gauge position correcting circuit for correcting the position of the gauge pattern. 2. The image processing system according to claim 1, wherein the image processing system detects a center position of each lead terminal from a width of the lead terminal in the terminal arrangement image in an X-axis direction and a Y-axis direction, or each of the lead terminals in the terminal arrangement image. 2. The pattern inspection apparatus according to claim 1, further comprising a center of gravity detection circuit that detects a center of gravity and sets the center of the lead terminal. 3. A process of converting an arrangement pattern of lead terminals imaged by the imaging device into a digital signal by an analog-to-digital conversion circuit, and storing the digitized terminal arrangement image in a first frame memory; A step of comparing the terminal arrangement reference pattern stored in the frame memory with the terminal arrangement image to detect the center position of each lead terminal, and the center position of each lead terminal and a terminal shape registered in advance. Setting the occupied area of the lead terminal from the step of: setting the hole position of the corresponding gauge pattern in accordance with the terminal array image; and comparing and comparing the occupied area of the lead terminal with the hole position of the gauge pattern. Judging whether the arrangement of the lead terminals is good or not, when the occupied area of at least one lead terminal deviates from the hole position of the gauge pattern; Pattern inspection method characterized by comprising the step of correcting the position of Jipatan.