JPH0213838A - Lead inspection method lead measuring apparatus and lead inspector used therefor - Google Patents

Abstract

PURPOSE:To detect a circumferential, vertical and diametrical deviation of position of leads by taking actual and false images of the leads of an electronic equipment to be inspected to judge various dimensions in the actual and false images in comparison with reference values. CONSTITUTION:Actual and false images A and B of leads 3 of an electronic equipment 1 to be inspected are taken facing each other using a TV camera 21 and an image taken thereof is inputted into an image processor 22, which 22 measures center positions X of the leads 3 and tip positions (a) and (b) of the actual images A and false images B separately based on the input images. Based on a measuring data thus obtained, pitches P of the leads 3, a distance (d) between the tip positions of the actual images A and the false image B and a difference (h) of either of the tip positions from a reference position Y0 are determined. Then, based on the pitches P, the distance (d) and the difference (h), it is judged whether the leads are within a normal range in circumferential, vertical and diametrical ways.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a lead measurement and inspection technique, and in particular to a technique for measuring and inspecting the position of a group of leads in an electronic device having a surface-mounted package. For example, a semiconductor integrated circuit device equipped with a surface-mounted package (
Hereinafter, it may be referred to as IC. ) is useful for inspecting the appearance of leads to determine whether they are good or bad.

[Conventional technology]

Recently, TCs have become smaller, more compact, and lighter, and in response to the demands for high-density packaging, ICs equipped with surface-mount packages (hereinafter sometimes abbreviated as surface-mount ICs) have been developed. ) are rapidly becoming popular. Along with the mounting of chip components, surface mount ICs are promoting automation of board mounting.

However, even with automatic chip component mounting equipment, it is impossible to achieve a correct placement rate of 1001%, and as the number of components per board increases, the cumulative defective placement rate also increases, and when evaluating one board as a unit. , we are now counting single- to double-digit percentage defects.

In order to quickly discover and eliminate such defective boards during the manufacturing process, there is a need for the development of an automatic inspection device for the mounting state.

On the other hand, on the supply side of surface-mounted ICs, in order to prevent the occurrence of mounting defects after mounting on a board, an external appearance inspection of the leads is performed before shipping the product.

However, there are no measurement standards defined for the inspection items for leads of surface-mounted ICs, and the positional relationship between the leads in a lead group row on each side of the package alone cannot unambiguously determine the state at the time of mounting. Since it is difficult to specify the conditions, visual inspection of the leads of surface mount ICs is currently performed manually.

Incidentally, an example that describes the chip component mounting inspection technique is "Electronic Materials, November 1987 issue," published by Kogyo Kenkyukai Co., Ltd., November 1, 1987, pages 63 to 69.

[Problem to be solved by the invention]

Relying on human labor to visually inspect the leads of surface-mounted ICs not only limits productivity improvement;
There are also limits to the reliability of testing.

Therefore, there is a need to develop a lead inspection device that can automatically perform a visual inspection of the leads of surface-mounted ICs.

The issues that need to be solved in the development of this lead inspection device are:
One example of this is to measure the mutual positional relationship of the leads mounted in that state and determine whether the appearance of each lead is good or bad in relation to the entire lead group.

A first object of the present invention is to provide a lead measurement technique that can automatically measure the positional relationship of a group of leads in an electronic device equipped with a surface-mounted package, assuming the state when surface-mounted. There is a particular thing.

A second object of the present invention is to provide a lead inspection technique that can automatically determine whether the lead appearance is good or bad based on the measurement.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Means to solve the problem]

An overview of typical inventions disclosed in this application is as follows.

That is, this is a lead inspection method for inspecting the positional relationship of a group of leads in an electronic device equipped with a surface mount package, in which a virtual image of the group of leads is made by confronting a real image thereof and a virtual image reflected on a mirror surface. , based on the image signals for the real image and the virtual image, measure the center position, real image tip position, and virtual image tip position of each lead, respectively, and further measure the pitch and real image of each lead based on this measurement data. The distance between the tip position and the virtual image tip position, and the difference between at least the real image or virtual image tip position and the reference position are determined, and the positional relationships in the circumferential direction, vertical direction, and radial direction are inspected for each lead. be.

[Effect]

According to the above-mentioned means, the lead X
It is possible to simultaneously measure the positional relationships in three directions: (circumferential direction), Y (radial direction), and Z (vertical direction).

As a result, based on the measurement data, the lead X, Y
, Z directions can be automatically inspected to see if the positional relationship is good or bad.

Since the inspection state corresponds to the state at the time of mounting an electronic device equipped with a surface mount type package because it is in contact with a mirror surface, the positional relationship of the leads of the electronic device is determined before mounting. It is famous for automatically inspecting the system assuming the waiting state.

[Example 1] Fig. 1 is a schematic diagram showing a lead inspection device which is an embodiment of the present invention, Figs. 2 and 3 are explanatory diagrams for explaining its operation, and Figs. The figure shows M as an object to be inspected.
FIG. 2 is a perspective view and a partially cutaway front view showing a mounting state of the SP-IC.

In this embodiment, the lead inspection device used in the lead inspection method according to the present invention is an IC equipped with a mini square package (hereinafter referred to as MSP/IC), which is an example of an IC equipped with a surface mount package. It is configured to be able to carry out a visual inspection of the lead group at )l.

The MSP-ICI as the object to be inspected is equipped with a resin-sealed package 2 that is formed into a substantially square flat shape using resin, and the four sides of this package 2 are bent and molded into a bat wing shape. A plurality of leads 3 are arranged horizontally in a line with their lower ends aligned, and protrude toward one end surface (hereinafter referred to as the lower surface side).

Then, this MSPiC 7 is mounted on a printed wiring board as shown in FIGS. 4 and 5.

4 and 5, the printed wiring board VI4 has a plurality of lands 5, and the resin-sealed MS which is the object to be mounted.
It is arranged to correspond to each lead 3 in the P-ICI, and is formed into a substantially rectangular thin plate shape using solder material, and the three groups of leads of this IcI are aligned and abutted on the five groups of lands, respectively. and each lead 3
and land 5 are electrically and mechanically connected by solder mound layer 6 formed by reflow soldering.

Therefore, in the state assumed at the time of implementation, MSP-I
The CI will be inspected for the following items regarding the positional relationship of its lead group.

(1) Circumferential spacing (pitch) between adjacent leads
.

(2) Height of the lead tip relative to the reference surface (mounting surface) (lifting of the lead tip from the land).

(3) Position of the lead in the package radial direction (bending of the lead in the inward and outward directions).

In this embodiment, this lead inspection device 10 includes a rotary table 11 that is arranged substantially horizontally and is rotatably supported, and the rotary table 11 is rotated by a suitable rotary drive device 12 such as a servo motor. is configured to be Further, the top surface of the rotary table 11 is equipped with a suction chuck 13 connected to a negative pressure supply path 14, and the rotary table 11 suctions the bottom surface of the MSP-ICI package 2 by the vacuum suction force of the suction chuck 13. This makes it possible to position and hold MSPiCl. A mirror surface 15 is formed on the upper surface of the table 11 so as to reflect the entire MSP-ICI positioned and held on the table 11 from its lower surface.

The mirror surface 15 may be formed by placing the mirror itself on the table 11, or may be formed by polishing the surface of the table 11 itself or applying a reflective coating. It doesn't matter, but there should be as little distortion as possible, and
It is desirable to form it to have wear resistance.

Diagonally above the rotary table 11 is a lead measuring television camera (hereinafter referred to as a camera), which serves as a lifting device that takes in real and virtual images of the lead group.

) 21 is installed at an approximately 45-degree downward inclination, and this camera 21 is attached to the MSP/ICI lead 3 held on the mirror surface 15 of the rotary table 11, as shown in the monitor image to be described later. It is set so that a real image of the lead group and a virtual image of the lead group reflected on the mirror surface 15 can be captured simultaneously. An image processing device 22, which together with the camera 21 substantially constitutes at least a part of the lead measuring device 20, is connected to the camera 21, and this image processing device 22 has a monitor 23 connected to one of its output terminals. The device is configured to send an image signal to monitor a desired image, and is also configured to send a predetermined measurement signal to the determination unit 24 connected to another output terminal.

This determination unit 24 is connected to a setting unit 25 for setting determination reference values regarding lead arrangement as described later, and the determination unit 24 receives actual measured values sent from the image processing device 22 and settings. By determining the difference between the set value sent from the unit 25 and comparing whether the difference is within the tolerance range, it is possible to determine if the actual measured value deviates from the reference value by more than the tolerance range. The device is configured to determine that the lead arrangement is defective and to transmit the determination result to an external device (not shown). - Further, a lighting device 16 is installed diagonally above the rotary table 11, and this lighting device 16 is arranged so that its illumination direction is as parallel as possible to the projection direction of the camera 21.
It is configured to illuminate three groups of leads on one side of the MSP/ICI held on the rotary table 11 from the camera 21 side.

Next, an embodiment of the lead inspection method according to the present invention will be described using the lead inspection apparatus having the above configuration.

A suitable transfer device (not shown) such as a vacuum suction head, etc.
When the MSP-IC1 as an object to be inspected is placed facing downward on the rotary table 11 and positioned,
Negative pressure is supplied to the suction chuck 13 from the negative pressure supply path 14, and the MSP/ICI is positioned and held on the mirror surface 15 of the rotary table 11.

When the MSP/ICI is positioned and held on the rotary table 11, the line of leads 3 protruding from one side of the package 2 is captured by the camera 21, its real image and the mirror surface 15.
The virtual image projected on the screen is simultaneously photographed. This camera 2
The output signal of 1 is sent to the image processing device 22. Image processing bag r! ! , 22, predetermined signal processing is performed;
If desired, real and virtual images of the group of leads 3 are monitored on the monitor 23 as shown in FIG.

Further, in the image processing device 22, for example, based on the image signal as shown on the monitor 23 in FIG. - Pn is determined by the process shown in FIG.

That is, as shown in FIG. 2(a), among the image signals from the camera 21, the real image A regarding the lead 3 is
Alternatively, a specific horizontal scanning line signal SX is extracted from the image signal for either one of the virtual images B.

Next, as shown in FIGS. 2-), a brightness change point detection process is performed on this horizontal scanning line signal SX.

Next, as shown in FIG. 2(C), center positions X+, Xt, . . . , corresponding to the center of each lead 3 are determined.
Each of n is measured by finding the center position between the points of change in brightness and darkness.

After the center position of each lead 3 measured in this manner is stored, it is appropriately transmitted to the determination unit 24 according to a command.

The determination unit 24 first determines the pitch dimensions P1, P2 between the adjacent leads 3.3, which correspond to the distances between the center positions X1 and Xt, and between Xt and X, measured in this way.
・Pn is obtained by the following equations.

Pl-XtXs, Pz-XsX
z '''Pn-Xn-Xn-1 Next, in the determination unit 24, the actual measured values PI, PI...Pn regarding the pitch obtained in this way,
The pitch P between each lead 3 is determined by continually determining the difference from the set value Po sent from the setting unit 25 and checking whether the magnitude of the difference is within the allowable value range.
, , P, . . . It is determined whether Pn is appropriate or not. That is, when the difference value between Pn-Po is within the range of allowable values, it is determined as "good J" and when the difference value between Pn-Po is outside the range of allowable values, it is determined as "bad". here,
The set value Po and allowable value are the MSP and [CL
It is preset in the setting section 25 based on the standard dimensions of.

The determination result is output to an external device as necessary. At this time, according to this embodiment, since it is possible to read the defective location and specify the error value thereof, it is possible to specify and instruct the reader to read the defective location. can be accelerated.

Next, in the image processing device 22, the tip position of each lead 3 in the real image and the tip position in the virtual image are determined by processing as shown in FIG.

That is, first, as shown in FIG. 3(a),
Center position X of each lead 3 determined by the above-mentioned process
+, Xz ... Vertical image signal sz,,s passing through Xn
zz...SZn are each extracted.

Next, as shown in FIG. 3(b), a brightness change point detection process is executed for each vertical image signal sz, sz, ...SZn, and the brightness change point is detected as the real image of each lead 3. Tip positions al, a2...an at A+,'At...An and virtual image B corresponding to these
1, Bz...Tip position b+, bz in Bn
... can be determined using coordinates as bn.

The real image tip position and virtual image position of each lead obtained in this way are multiplied by f and +2, and then sent to the determining section 24 and setting section 25 as appropriate in accordance with the instructions thereof.

First, the determination unit 24 calculates the difference between the real image tip positions a I , at , . . . , an of each lead and the virtual image tip positions tb, , b, .

h+ “al bt, hz −az bt,
...hn=an-bn This difference value corresponds to the distance between the real image tip and the virtual image tip,
The larger this value is, the more the leads are lifted from the mounting land surface.

Therefore, in the determination unit 24, the distance dimensions h+, hz, . . . hn, which were actually measured in this way, are
The difference from the preset reference interval called up from the setting unit 25 is determined from time to time, and it is checked from time to time whether the difference value is within the range of the preset tolerance value that is also called up. As a result, it is determined whether or not each lead 3 is lifted from the mounting surface.

For example, in FIG. 1, the fifth lead 3e from the left
is lifted upward, and as a result, hs becomes larger than the allowable range, so it is determined to be defective. The determination result is outputted to an external device as necessary, and at that time, the defective location and its error value are respectively dealt with for each lead.

On the other hand, in the setting unit 25, a virtual reference plane coordinate position Yo is determined by the following equation for calculating the average position of the real image tip position and the virtual image tip position, and this position Yo determines whether or not the lead is bent in the internal and external directions. It is assumed to be the reference value for judgment. In other words, this virtual reference plane position Yo is the position of the reference line on the mirror surface I5 on which the three lead groups are placed, where the three lead groups should be lined up, that is, the position of the reference line where the land five groups should be aligned when this ICI is mounted. Corresponds to the position where

Yo= (al +tz)/2 + (ax +bt)/2・-・(an+bn)/2
Next, in the determination unit 24, this center line position 3Yo is called from the setting unit 25, and the tip position a+%ax in the real image of each lead is called from the image processing unit 22.
. . an, and the tip position in the virtual image, b,
...bn are called sequentially, and these leading positions 1fa+
,at...an,andsu,,,bt・
...difference between bn and center line position Yo, al-Yo, at
-Yo --・an-Yo andsu, -Yo, bz
-Yo ·--bn-Yo is obtained one by one. and,
Whether or not the magnitude of these differences falls within a preset tolerance range is checked from time to time, thereby determining whether or not the internal and external positions of each lead 3 are appropriate.

For example, in Figure 1, the seventh glue line on the right is 3.
h is the difference between the real image tip position a and the virtual image tip position S,
is within the acceptable range, but av -Y.

The difference da and the difference db between bw and Yo are outside the allowable range (positive or negative tendency).

), it is determined that the bend is in one direction, either inside or outside.

The determination result is output to an external device as necessary. At this time, the defective location and its error value can be associated with each lead, as described above.

Thereafter, the rotary table 11 is sequentially rotated through 90 degrees, and the above-described operations are repeated for the three groups of leads on the remaining three sides, thereby performing the visual inspection. In this case, the lifting and wounding work and the subsequent image processing can be performed in parallel.

According to the embodiment described above, the following effects can be obtained.

(]) An electronic device equipped with a surface-mounted package is placed on a mirror surface, a real image and a virtual image of the lead group are captured by a lifting device, and the image signals are processed. It is possible to automatically measure the positional relationship of each lead of an electronic device in a state in which it is in the waiting state before mounting, assuming that it will be mounted, thereby reducing the need for manual work. The lead measurement task can be performed automatically without having to do so.

(2) Based on the measurement results of the positional relationship of each lead in (1) above, perform an external appearance inspection for circumferential bending and pitch suitability of the lead, vertical deformation, and radial inward/outward bending. By doing this, it is possible to automate the external appearance inspection of the leads, thereby increasing the quality and reliability of the electronic device that is the object of the inspection, and ensuring that the electronic device that has undergone this inspection is properly mounted during automatic mounting. rate can be increased.

(3) By increasing the correctness of mounting electronic devices during automatic mounting through the inspection in (2) above, it is possible to promote the surface mount type of electronic devices, so products that meet the demands for high-density mounting. can be provided.

(4) By placing an electronic device equipped with a surface-mounted package on a mirror, and capturing a real image and a virtual image of the lead group using an imaging device, and processing the image signals, a unidirectional Because it is possible to simultaneously measure the positional relationships of the leads in three directions: X (circumferential direction), Y (radial direction), and Z (vertical direction) using only images from In addition, the time required for visual inspection can be significantly shortened.

(5) In (4) above, the only thing that actually consumes time is the time required to capture one screen of the lead group array, and the subsequent image processing can be performed electrically. By performing image processing in parallel with imaging time and electronic device loading and unloading time, measurement work time and inspection work time can be further shortened.

[Embodiment 2] FIG. 6 is a schematic diagram showing a lead inspection device which is another embodiment of the present invention, FIGS. 7 and 8 are diagrams for explaining its operation, and FIGS. 9 and 10 The figures are a perspective view and a partially cutaway front view showing a mounting state of a PLCC/IC as an object to be inspected.

In Example 2, the lead inspection device according to the present invention includes:
An IC equipped with a plastic lead-lid chip carrier package (hereinafter referred to as PLCC IC) is an example of an IC equipped with a surface mount package.
31, so that the visual inspection of the lead group can be carried out.

The P L CC/IC 31 as an object to be inspected is equipped with a resin-sealed package 32 formed of resin into a substantially square flat shape, and the four sides of this package 32 are bent into a J-bent shape. Molded or multiple one do 33,
They are arranged horizontally in a row with their bottom edges aligned, and one end side (hereinafter referred to as
It should be on the bottom side. ).

Then, this PLCC-IC 31 is mounted on a printed wiring board as shown in FIGS. 9 and 10.

In FIGS. 9 and 10, printed wiring board 34
A plurality of lands 35 are arranged to correspond to each lead 33 of the resin-sealed PLCC/IC 31 to be mounted, and are formed into a substantially rectangular thin plate shape using solder material. This RCA i in land 35 group
The groups of leads 33 are aligned and in contact with each other, and each lead 33 and land 35 are electrically and mechanically connected by a solder layer 36 formed by reflow soldering.

Therefore, in the state assumed at the time of implementation, the PLCC-
The IC 31 will be inspected for the following items regarding the positional relationship of its lead group.

(1) Circumferential spacing (pitch) between adjacent leads.

(2) Height of the bottom end surface of the lead relative to the reference surface (mounting surface) (lifting of the bottom end surface of the lead from the land).

(3) Position of the lead in the radial direction of the package (bending of the lead in the inward and outward directions) In the second embodiment, the lead inspection device 40 is mounted on a rotary table 11 that is arranged substantially horizontally and is rotatably supported.
The rotary table 11 is configured to be rotated by a suitable rotary drive device 12 such as a servo motor. Further, the top surface of the rotary table 11 is equipped with a suction chuck 13 connected to a negative pressure supply path 14, and the rotary table 11 suctions the bottom surface of the package 32 of the PLCC/IC 31 by the vacuum suction force of the suction chuck 13. This makes it possible to position and hold the PLCC-IC 31. On the upper surface of this table 11, a mirror surface 15 is positioned and held on the table 11.
It is formed so that the entire CC-IC 31 can be viewed from its bottom surface.

The table 11 is equipped with a ring-shaped lighting device 17, and this lighting device 1t17 is a PLC
It is configured to illuminate the lead 33 group row outward from below the C-IC 31.

On the horizontal side of the rotary table 11, there is a television for lead measurement as a layer image device that captures real and virtual images of the lead row.
A camera (hereinafter referred to as camera) 41 is installed approximately horizontally, and as shown in the monitor image to be described later, this camera 41 is mounted on the mirror surface of the rotating table 11.
It is set so that a real image of the group of leads 33 of the PLCC-rc 31 held on the mirror surface 15 and a virtual image of the group of leads reflected on the mirror surface 15 can be simultaneously captured.

The camera 41 includes a lead measuring device 46 together with the camera 41.
An image processing device 42 that substantially constitutes at least a portion of
is connected to the image processing device 42, and the image processing device 42 is configured to send an image signal to a monitor 43 connected to one of its output terminals to monitor a desired image. It is configured to transmit a predetermined measurement signal to the connected determining section 44.

A setting section 45 is connected to the determination section 44 for setting determination reference values regarding lead arrangement, as will be described later. Then, the determining unit 44 determines the difference between the actual measured value sent from the image processing device 42 and the setting value sent from the setting unit 45, and compares the difference to see if it is within the tolerance range. By doing so, if the actual measured value deviates from the reference value by more than the allowable value range, it is determined that the lead arrangement is defective, and the determination result is transmitted to an external device (not shown). ing.

Next, a second embodiment of the lead inspection method according to the present invention will be described using the lead inspection apparatus having the above configuration.

A suitable transfer device W (not shown) such as a vacuum suction head, etc.
When the PLCC-IC 31 as an object to be inspected is placed and positioned on the rotary table 11 facing downward, negative pressure is supplied to the suction chuck 13 from the negative pressure supply path 14, and the PLCC-IC 31 is placed on the rotary table 11. 11 mirror surface 1
5 and is held in position. At the same time, the ring lighting systemff
17, the three lead groups and rows of the PLCC/IC 31 are illuminated from the inner side. When the PLCC-I C31 is positioned and held on the rotary table 11 and illuminated from the inside, a line of leads 33 protruding from the side surface of the package 32 is reflected by the camera 41 on its real image and on the mirror surface 15. A virtual image is captured at the same time. The output signals of the camera 41 are respectively transmitted to an image processing device 42. In the image processing device 42, predetermined signal processing is executed, and as desired, images related to the real image and virtual image of the group of leads 33 are displayed on the monitor 43. Monitored as shown in the figure. At this time, since the lead 33 group is illuminated from the inside side toward the camera 41,
In the image, the part of lead 33 is black, and the adjacent lead 3
3. The black and white are reversed so that the gap at 33 becomes white.

In addition, in the image processing device 42, for example, based on the image signal as shown on the monitor 43 in FIG. ...Pn is obtained by the process shown in FIG.

That is, as shown in FIG. 7(a), among the image signals from the camera 41, in the image signal for either the real image A or the virtual image B for the lead 33, a specific horizontal scanning line signal SX is extracted.

Next, as shown in FIG. 7(b), a brightness change point detection process is performed on this horizontal signal SX.

Subsequently, as shown in FIG. 7(C), center positions Xl, X! corresponding to the center of each lead 33 are determined. ...Xn
is measured by the device by finding the center position between the brightness change points.

After the center position of each lead 33 measured in this manner is stored, it is appropriately transmitted to the determination unit 44 according to a command.

The determination unit 44 first determines the pitch dimensions P+, Pg between the adjacent leads 33 and 33, which correspond to the distances between the center positions X and Xz, and between Xt and X8 measured in this way.
. . . Pn is obtained by the following equations.

P+ −Xz −X+ , Px −Xs Xz”
'Pn=Xn It is possible to determine whether the pitches P3, P2...Pn between each lead 33. judge. That is, when the difference value of Pn-Pd is within the range of allowable values, it is judged as "good", and when the difference value of Pn-Po is outside the range of allowable values, it is judged as "bad". Here, the set value Po and allowable value are the PLCC/IC3 of the inspected object.
The dimensions are preset in the setting section 45 based on the standard dimensions of No. 1.

The determination result is output to an external device as necessary. At this time, according to this embodiment, since the lead of the defective location can be specified and instructed, the task of discovering the cause of the defective occurrence can be speeded up in cases such as when a defective product is repeatedly output from the same location. I can do it.

Next, in the image processing device 42, the tip position of each lead 33 in the real image and the tip position in the virtual image are determined by processing as shown in FIG.

That is, first, as shown in FIG. 8(a),
Center position 2 of each lead 33 determined by the above-described processing
Vertical signals sz,, s passing through x+, xi...Xn
zt...SZn are each extracted.

Next, as shown in FIG. 8(C), a brightness change point detection process is executed for each vertical signal sz, sz, ...SZn, and each of the brightness change points corresponds to the point of each lead 33. Real image AI, A! ...Tip position ar, az ...an and the corresponding virtual images B+, Bz ...Tip position b+ in Bn
, bz . . . bn are determined by coordinates.

After the real image tip position and virtual image position of each lead determined in this way are stored, the determining unit 44 and the setting unit 4
5 as appropriate in accordance with the command.

First, in the determination unit 44, the difference between the real image tip position a+%at...an and the virtual image tip position S, bt...bn7 of each lead is determined by the following equation.

h+ -at bI% hz -az-bz,...
・hn-an-bn This difference value corresponds to the distance between the real image tip and the virtual image tip,
The larger this value is, the more the leads are lifted from the mounting land surface.

Therefore, in the determination unit 44, the distance dimensions FB, hz, . . . hn, which were actually measured in this way, are
The difference from the preset reference interval called up from the setting unit 45 is determined from time to time, and it is checked from time to time whether the difference value is within the range of the preset tolerance value that is also called up. As a result, it is determined whether or not each lead 33 is lifted from the mounting surface.

For example, in FIG. 6, the fifth lead 33 from the left
Since e rises upward, h becomes larger than the allowable range, so it is determined to be defective. The judgment results are output to external equipment as necessary, and at that time,
The defective location and its error value are associated with each lead.

On the other hand, in the setting unit 45, a virtual reference plane coordinate position Yo is determined by the following equation for calculating the average position of the real image tip position and the virtual image tip position, and this position Yo determines whether or not the lead is bent in the internal and external directions. It is set as a reference value for judgment. In other words, this virtual reference plane position 1tYo is the position of the reference line where the lead 33 groups should be aligned in a straight line on the mirror surface 15 on which the lead 33 groups are placed, that is, this PL
This corresponds to the position where the land groups 35 are aligned when the CC-IC 31 is mounted.

Yo= (at +b+ )/2 + <at +bz )/2 ... (an + bn
) /2 Next, in the determination unit 44, this center line position Yo is called from the setting unit 45, and the tip position W a I in the real image of each lead is called from the image processing unit 42.
, a Z ...an, and the tip position 1 in the virtual image
mb, ,b! ...bn are called sequentially, and these tip positions al, am ...an, and su, b
, ...difference between bn and center line position Yo, a, -Y
o, at -Yo ---an-Yo and su, -Yo
, bz -Yo ... bn-Yo are obtained one by one.

Then, whether or not the magnitude of these differences falls within a preset tolerance range is checked from time to time, thereby determining whether or not the inner and outer positions of each lead 33 are appropriate.

For example, in Figure 6, the 7th glue on the right side and 3
3h is the real image tip position 1lfa? The difference between the position of the tip of the virtual image and the tip position of the virtual image is within the permissible range, but a7-Y.

The difference da, and the difference db between -Yo are outside the allowable range (positive or negative tendency).

), it is determined that the bend is in one direction, either inside or outside.

The determination result is output to an external device as necessary. At this time, the defective location and its error value can be associated with each lead, as described above.

Thereafter, the rotary table 11 is sequentially rotated through 90 degrees, and the above-described operations are repeated for the remaining three groups of leads 33, thereby performing the visual inspection. In this case, the imaging work and subsequent image processing can be performed in parallel.

According to the second embodiment, the same effect as in the first embodiment can be obtained, but since the lead group is illuminated from inside toward the imaging device, the projected image is inverted in black and white.
The accuracy of measuring the positional relationship of the leads through image processing can be further improved.

[Embodiment 3] - Fig. 11 is a schematic diagram showing a lead inspection device according to another embodiment of the present invention, Figs. 12 and 13 are diagrams for explaining its operation, and Fig. 14 FIG. 15 is a perspective view and a partially cutaway front view showing the mounting state of a PPP IC as an object to be inspected.

In Example 3, the lead inspection device according to the present invention includes:
An IC with a flat pack package, which is an example of an IC with a surface mount package.
(hereinafter referred to as PPP-IC) 51 is configured to be able to conduct an external appearance inspection of the lead group.

The PPP-IC 51 as an object to be inspected is a resin-sealed package 5 formed of resin into a substantially square flat shape.
2, and the four sides of this package 52 are bent into a gull wing shape, and have a plurality of doors 53,
They are arranged horizontally in a row with their bottom edges aligned, and one end side (hereinafter referred to as
It should be on the bottom side.

).

Then, this FPP IC 51 is mounted on a printed wiring board as shown in FIGS. 14 and 15.

In FIGS. 14 and 15, printed wiring board 5
4, a plurality of lands 55 are arranged to correspond to each lead 53 in the resin-sealed Fl) P-IC 51 to be mounted, and are formed into a substantially rectangular thin plate shape using solder material. This IC51 is placed in this land 55 group.
The groups of leads 53 are aligned and in contact with each other, and each lead 53 and land 55 are electrically and mechanically connected by a solder layer 56 formed by reflow soldering.

Therefore, in the state assumed at the time of implementation, FPP-I
C51 will be inspected for the following items regarding the positional relationship of its lead group.

(1) Circumferential spacing (pitch) between adjacent leads
.

(2) Height of the bottom end surface of the lead relative to the reference surface (mounting surface) (lifting of the bottom end surface of the lead from the land).

(3) Position W of the lead in the package radial direction (bending of the lead in the inward and outward directions).

In the third embodiment, a lead inspection device similar to that used in the first embodiment is used for a PPP-IC lead inspection method, which is an embodiment of the lead inspection method according to the present invention. Since the structure of this lead inspection device is similar to that of the first embodiment, the same reference numerals as those of the first embodiment are given in FIG. 11, and a description of the structure will be omitted.

Next, regarding the case where this lead inspection device is used, a PPP-IC lead inspection method according to the third embodiment will be described with respect to the differences from the first embodiment.

The difference between the third embodiment and the first embodiment is that the FPP/IC
Since the leads 53 of 51 are bent into a gull wing shape, the bending lines of the leads 53 and the edges of the thickness of the leads are bright and dark, as shown in FIGS. 11 to 13. The other point of the third embodiment is that it appears as noise in the change point detection process, and the other point of the third embodiment is that it appears as noise in the change point detection process.
It is almost the same as.

It is considered that the following means can be taken as means for eliminating noise in the process of detecting the brightness change point.

(1) Increase the luminous intensity and amount of light of the illumination device 16, and
Irradiate towards the thickness edge of 3. This illumination significantly attenuates the level of noise that appears at brightness and darkness transition points.

(2) In the process of detecting brightness change points, the darkness value is set strictly.

(3) In the brightness change point detection process, the change points to be left are limited to a pair of change points where the real image and virtual image face each other, and the other change points are set to be deleted.

Incidentally, the PPP/IC lead inspection method is not limited to using the lead inspection apparatus W10 of the first embodiment, but can also be carried out using the lead inspection apparatus 40 of the second embodiment. In this case, since the image of the lead 53 is inverted in black and white, the phenomenon in which the bending line of the lead 53 and the edge of the lead thickness appear as noise at the brightness change point is eliminated in the process of detecting the brightness change point. Or most of them will be eliminated.

Although the invention made by the present inventor has been specifically explained above based on Examples, it goes without saying that the present invention is not limited to the Examples and can be modified in various ways without departing from the gist thereof. Nor.

For example, in lead inspection equipment and lead measurement equipment, not only one imaging device but also multiple imaging devices can be installed to simultaneously capture images of lead group rows on multiple sides, thereby eliminating the need for a rotary table. You can.

Further, the specific configurations of the imaging device, the table for positioning and holding the object to be inspected, the chuck, the image processing device, the monitor, the determination section, and the setting section are not limited to those shown in the above embodiments; It is desirable to select it appropriately depending on the specific conditions such as the shape, structure, size, etc.

In the embodiment described above, a case has been described in which the lead measuring device is incorporated into a lead testing device and used in a lead testing method. It can also be used to measure the amount of bending of the lead in the radial direction, the amount of lifting of the tip of the lead, etc., and its uses are not limited.

The above explanation will mainly focus on the invention made by the present inventor in the MSP/IC, PL field, which is the background of the invention.
Although the case where it is applied to the lead inspection technology of CC/IC1 and PPP-IC has been explained, it is not limited thereto, and the lead inspection technology of other ICs equipped with surface mount packages, electronic components, and electronic devices, and the case where it is applied is explained. Lead measurement technology Lead inspection technology and lead measurement for electronic devices with insertion type external terminals such as ICs, etc., which can be applied to all systems and, if necessary, with dual in-line packages. It can also be applied to technology.

〔Effect of the invention〕

A brief explanation of the effects obtained by typical inventions disclosed in this application is as follows.

An electronic device equipped with a surface-mounted package is placed on a mirror surface, a real image and a virtual image of the group of leads are captured by an imaging device, and the image signals are processed to display each of the electronic devices. It is possible to automatically measure the positional relationship of each lead in the mounting state before mounting, assuming the positional relationship of the leads at the time of mounting. measurement tasks can be performed automatically.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing a lead inspection device which is an embodiment of the present invention, Figs. 2 and 3 are explanatory diagrams for explaining its operation, and Figs. 4 and 5 show an object to be inspected. FIG. 2 is a perspective view and a partially cutaway front view showing the mounting state of the MSP/IC as the MSP/IC. FIG. 6 is a schematic diagram showing a lead inspection device according to another embodiment of the present invention, FIGS. 7 and 8 are diagrams for explaining its operation, and FIGS. 9 and 10 are diagrams showing an object to be inspected. PLcc-t as
FIG. 3 is a perspective view and a partially cutaway front view showing the mounting state of the device. FIG. 11 is a schematic diagram showing a lead inspection device according to another embodiment of the present invention, FIGS. 12 and 13 are diagrams for explaining its operation, and FIGS. 14 and 15 are FPP/I as an inspection object
FIG. 4 is a perspective view and a partially cutaway front view showing the mounting state of C. 1.31.51...Electronic device (tested object), 2.32
．． 52...Package, 3.33.53...Lead, 4.34.54...Printed wiring board, 5.35.
55... Land, 6.36.56... Solder mound layer, 1O140... Lead inspection device, 11... Rotary table, 12... Rotation drive device, 13... Suction chuck, 14... ... Negative pressure supply path, 15... Mirror surface, 16.
17... Illumination device, 20.46... Lead measuring device, 21.41... Camera (imaging device), 22.42...
...Image processing device, 23.43...Monitor, 24.4
4... Judgment section, 25.45... Setting section. Agent Patent Attorney Tatsuya Kajihara Figure 2 (Q) Figure 3 (a) w & 4 Figure 5 Figure 70 (Q) Figure 80 +Q) Figure 9 Figure 10 Figure 12 (Q) ψ heart "Iql" 13 causes (Q)

Claims (9)

[Claims] 1. A lead inspection method for inspecting the positional relationship of a group of leads in an electronic device equipped with a surface mount package, the method comprising: imaging a real image of the group of leads and a virtual image reflected on a mirror surface facing each other; Based on the image signals for the real image and the virtual image, the center position, real image tip position, and virtual image tip position are respectively measured for each lead, and further, based on this measurement data,
For each lead, find the pitch, the distance between the real image tip position and the virtual image tip position, and at least the difference between the real image or virtual image tip position and the reference position, and calculate the positional relationship in the circumferential direction, vertical direction, and radial direction for each lead. A lead inspection method characterized by inspecting. 2. One horizontal scanning line signal from the image signal of at least one of the real image and the virtual image is extracted, a process of detecting brightness change points is performed on this scanning line signal, and the center position between the change points is determined. 2. The lead inspection method according to claim 1, wherein the center position of each lead is measured by 3. A vertical image signal passing through the center position of each lead is extracted, a process of detecting a brightness change point is executed for each vertical image signal, and each brightness change point is measured as a real image tip position and a virtual image tip position, respectively. A lead inspection method according to claim 1, characterized in that: 4. By calculating the interval between the center positions of each lead, the pitch between each lead is determined, and by comparing this pitch with a preset value, the position of the leads in the circumferential direction can be determined. The lead inspection method according to claim 1, wherein a lead inspection method is performed. 5. By calculating the distance between the real image tip position and the virtual image tip position for each lead, and comparing these actual distance dimensions with preset values, the vertical position of the lead can be calculated. 2. The lead inspection method according to claim 1, wherein the lead inspection method is characterized in that the quality of the lead is inspected. 6. Calculate the distance between the real image tip position and the virtual image tip position for each lead, find the average value of these gap dimensions, assume a reference position, and set this reference position and each real image and virtual image tip position, respectively. By comparing
2. The lead inspection method according to claim 1, wherein the lead is inspected for good or bad position in the radial direction. 7. A lead measuring device for measuring the positional relationship of a group of leads in an electronic device equipped with a surface mount package, the mirror surface being disposed on the mounting surface side of the group of leads and projecting at least a portion of the lead group in opposition to its real image. and an imaging device that images the real image of the lead group and the virtual image reflected on the mirror surface while facing each other, and the mutual positional relationship of the lead group is determined based on the image signals of the real image and the virtual image of this imaging device. A lead measuring device comprising: an image processing device for measuring. 8. 8. The lead measuring device according to claim 7, further comprising an illumination device that illuminates the lead group toward an imaging device. 9. A lead inspection device for inspecting the positional relationship of a group of leads in an electronic device equipped with a surface mount package, the mirror surface being disposed on the mounting surface side of the group of leads and reflecting at least a portion of the lead group in opposition to its real image. and an imaging device that images the real image of the lead group and the virtual image reflected on the mirror surface while facing each other, and the mutual positional relationship of the lead group is determined based on the image signals of the real image and the virtual image of this imaging device. Based on the image processing device to be measured and the measurement data of this image processing device, the pitch, the interval between the real image tip position and the virtual image tip position, and at least the difference between the real image or virtual image tip position and the reference position are determined for each lead. 1. A lead inspection device comprising: a determination unit that determines circumferential, vertical, and radial positional relationships for each lead.