JPH05114640A - Method and device for measuring lead, and lead tester using same - Google Patents

Abstract

PURPOSE:To measure accurately each position of leads irrespective of their lead damages. CONSTITUTION:When GFP and ICI are loaded on a reference surface 15 and the groups of leads 3 which include the reference plane are photographed with an image sensing device 21 so as to measure the edge position of each lead based on an image signal, one horizontal scanning line signal is extracted so that the processing which defines the change point between light and darkness may be executed. The edge points of the lead on both right and left sides are predicted. A change point XLn, which is nearest and positioned virtually on the right side of the predicted position DLn on the left side, is determined. A change point XRn, which is nearest and positioned on the left side of the predicted position DRn virtually on the right side, is determined, thereby measuring the edge position 3L and 3R of each lead on the both right and left sides. Since the detection processing of the left sided edge and the right sided edge of the leads is executed inwardly from the outside of the leads, a noise signal caused by a defect existing in the leads can be eliminated. It is, therefore, possible to measure the lead edges without any subject to the effect of a lead defect or the roughness of a cut surface of a lead.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead measuring and inspecting technique, and more particularly to a technique for measuring and inspecting the position of a lead group in an electronic device equipped with a surface mount type package. A semiconductor integrated circuit device (hereinafter sometimes referred to as an IC) including
The present invention relates to the one effectively used for inspecting the good or bad of the appearance of the lead in.

[0002]

2. Description of the Related Art Recently, ICs have been further reduced in size, thickness, and weight, and in response to the demand for high-density mounting, ICs equipped with surface mounting type packages (hereinafter referred to as surface mounting type ICs). Is abbreviated.) Has achieved rapid spread.
The surface mount type IC, together with the mounting of the chip component, promotes automation of mounting on the substrate.

However, even with an automatic chip component mounting apparatus, it is not desirable to have a proper mounting rate of 100%, and as the number of components per board increases, the cumulative mounting failure rate also increases, with one board as a unit. When evaluated, it has come to count one to two digit percent defects. In order to promptly find and eliminate such a defective substrate in the manufacturing process, development of an automatic inspection device for the mounted state is desired.

An example of the chip component mounting inspection technique is "Electronic Material 19
Issued on Nov. 10, 1987, P63-
There is P69.

On the other hand, on the supply side of the surface mount type IC, in order to prevent occurrence of mounting failure after mounting on the printed wiring board, a lead appearance inspection is carried out before product shipment.

However, the measurement standard is not defined in the inspection items of the leads of the surface mount type IC, and the positional relationship between the leads in the lead group row on each side surface of the IC package is not sufficient. Since it is difficult to unambiguously define the state, the visual inspection of the leads of the surface mount type IC is currently performed by human work.

If the visual inspection of the leads of the surface mount type IC relies on human work, not only is there a limit to the improvement of productivity, but there is also a limit to the reliability of the inspection. Therefore, it is necessary to develop a lead inspection apparatus that can automatically perform a visual inspection of the leads of the surface mount type IC.

As a problem to be solved in the development of this lead inspection apparatus, assuming the state of mounting the surface mounting type IC, the positional relationship between the leads in that state is measured, and In this relationship, the quality of the appearance of each lead is determined.

As a means for solving such a problem, Japanese Laid-Open Patent Publication No. 2-13838 proposes the following lead inspection method. That is, it is a lead inspection method for inspecting the positional relationship of a lead group in an electronic device including a surface mount type package, in which a real image of the lead group and a virtual image projected on a mirror surface are faced to each other and imaged. , The center position of each lead and the real image tip position and the virtual image tip position of each lead are measured based on the image signal of the real image and the virtual image, and the pitch and the real image of each lead are measured based on the measurement data. Lead inspection in which the distance between the 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 obtained, and the circumferential, vertical, and radial positional relationships are inspected for each lead. Is the way.

According to this lead inspection method, the X (circumferential direction), Y (radial direction), and Z of the lead can be obtained by using only the image in one direction.
The positional relationship in three directions (up and down direction) can be measured at the same time. As a result, based on the measurement data, it is possible to automatically inspect the good or bad of the positional relationship of the leads in the three directions of X, Y, and Z.

Since the inspection state corresponds to the mounting state of the electronic device equipped with the surface mount type package because it is in contact with the mirror surface, the positional relationship of the leads of the electronic device is mounted. Assuming the state at the time of mounting before,
You are inspecting automatically.

[0012]

However, in the above lead inspection method, the IC is mounted on the mirror surface,
Since each position of the lead is measured using image processing, if there are scratches on the surface of the lead due to contact of electrodes during cutting and molding of the lead or inspection of electrical characteristics, measurement of each position of the lead The accuracy is reduced and lead inspection becomes insufficient.

An object of the present invention is to provide a lead measuring technique and a lead inspecting technique capable of sufficiently measuring each position of the lead even when the lead has a scratch or a rough cut surface. Especially.

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

[0015]

The typical ones of the inventions disclosed in the present application will be outlined below.

That is, in a lead measuring method for measuring the positional relationship of lead groups in an electronic device equipped with a surface mount package, the electronic device is placed on a reference plane and the lead group of the electronic device is placed on the reference plane. When the edge position of each lead is measured based on the image signal of the image pickup including the image pickup device, one horizontal scanning line signal in the image signal of the lead is extracted, and this scanning line is extracted. Brightness change point detection processing is performed on the signal, the left and right edge positions of the lead are predicted, and the change point closest to the right is calculated from the roughly left edge predicted position. From this, it is possible to measure the left and right edge positions of each lead by obtaining the change point located closest to the left. And butterflies.

[0017]

According to the above-described means, the detection processing for the left edge and the right edge of the lead is executed from the outer side to the inner side of the lead, so that noise signals due to scratches and cut surfaces existing in the lead are not generated. Will be removed. Therefore, the edge of the lead can be accurately measured without being affected by the scratch formed in the lead or the roughness of the cut surface.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic diagram showing a lead inspection apparatus which is an embodiment of the present invention, FIGS. 2 to 5 are explanatory views for explaining the operation thereof, and FIG. 6 is a QFP as an inspection object. FIG. 6 is a perspective view and a partially cut front view showing a mounted state of an IC.

In the present embodiment, the lead inspection apparatus in which the lead measuring method according to the present invention is implemented is an IC equipped with a quad flat package which is an example of an IC equipped with a surface mount type package (hereinafter referred to as "IC"). QFP / IC
Say. ) 1), the external appearance inspection of the lead group can be performed.

The QFP IC1 as an object to be inspected is provided with a resin-sealed package 2 which is formed of resin into a substantially square flat plate shape, and four side surfaces of this package 2 have a gull wing shape. A plurality of leads 3 formed by bending are arranged in a row in a row with their lower ends aligned, and projecting toward one end surface side (hereinafter referred to as the lower surface side).

The QFP IC1 is mounted on the printed wiring board as shown in FIGS. 6 (a) and 6 (b).

In FIG. 6, a printed wiring board 4 is provided with a plurality of lands 5, and a resin-sealed QFP.
It is arranged so as to correspond to each lead 3 in IC1,
It is formed into a substantially rectangular thin plate using a solder material, and the leads 3 of the IC 1 are aligned and abutted against the lands 5 and the leads 3 and the lands 5 are reflow-soldered. Are electrically and mechanically connected by the solder fill layer 6 formed by.

Therefore, the QFP IC1 is inspected for the following items regarding the positional relationship of the lead group under the condition that the QFP IC1 is mounted. The circumferential spacing (pitch) between adjacent leads. Parallel bending in the circumferential direction of the lead group. Height of the lead tip with respect to the reference surface (mounting surface) (lifting of the lead tip from the land). The height position of the root of the lead (as a guide for the distance between the wiring board and the resin-sealed package during mounting).

In this embodiment, this lead inspection apparatus 1
0 is provided with a rotary table 11 which is arranged substantially horizontally and is rotatably supported, and the rotary table 11 is configured to be rotated by a suitable rotary drive device 12 such as a servomotor. Further, the rotary table 11 is equipped with a suction chuck 13 connected to a negative pressure supply passage 14 on the upper surface thereof.
By sucking the lower surface of the package 2 of the QFP / IC1 by a vacuum suction force which does not cause deformation of the contact lead with the reference surface, the QFP / IC1 can be positioned and held.

A reference surface 15 is provided on the upper surface of the table 11.
Is a QFP / IC that is positioned and held on the table 11.
1 is formed so as to support the entire surface 1 uniformly from the lower surface thereof. The reference surface 15 may be formed by applying a non-reflective coating on the table 11, and the forming means is not limited, but it is free from distortion as much as possible, and is less likely to be scratched and wear-resistant. It is desirable to form so as to have a property.

On the side of the reference surface 15 of the rotary table 11, a TV camera for lead measurement (hereinafter referred to as a camera) 21 as an image pickup device for capturing an image of the lead group.
However, QFP on the rotary table 11 parallel to the reference plane 15
It is arranged and installed so as to shoot the IC1. This camera 21 has a QF held on the reference surface 15 of the turntable 11, as shown in the monitor image below.
It is set so that the lead 3 group of the P.IC1 can be imaged.

An image processing device 22 which substantially constitutes at least a part of the lead measuring device 20 together with the camera 21 is connected to the camera 21, and this image processing device 22 is connected.
Is configured to send an image signal to a monitor 23 connected to one of its output terminals to monitor a desired image, and a predetermined measurement signal to a determination unit 24 connected to another output terminal. Is configured to send. An edge predicted position input device 26 is connected to the other input end of the image processing device 22.
Reference numeral 6 is configured to input the predicted edge position to the image processing device 22 by the operation described later.

As will be described later, a setting unit 25 for setting a determination reference value regarding the read sequence is connected to the determination unit 24, and the determination unit 24 is connected to the determination unit 24 so that the actual measurement value transmitted from the image processing device 22 is obtained. And the set value transmitted from the setting unit 25 are obtained, and whether the difference is within the range of the allowable value or not is compared to determine that the actual measured value is out of the range of the allowable value from the reference value. In this case, the read arrangement is determined to be defective and the determination result is transmitted to an external device (not shown).

An illuminating device 16 is installed diagonally above the turntable 11, and the illuminating device 16 connects the lead 3 group on one side of the QFP IC 1 held on the turntable 11 to the camera 21 side. It is configured to illuminate from above.

Next, an example of a lead inspection method in the case of using the lead inspection apparatus having the above-mentioned structure will be described.

By using a suitable transfer device (not shown) such as a vacuum suction head or the like, the QFP / IC1 as the object to be inspected.
Is placed face down on the rotary table 11 and is positioned, negative pressure is supplied to the suction chuck 13 from the negative pressure supply path 14, and the QFP / IC 1 is positioned and held on the reference surface 15 of the rotary table 11. It

When the QFP / IC 1 is positioned and held on the rotary table 11, a row of the leads 3 protruding from one side surface of the package 2 is photographed by the camera 21.
The output signal of the camera 21 is transmitted to the image processing device 22. Predetermined signal processing is executed in the image processing device 22. In addition, if desired, the image of the lead 3 group is monitored on the monitor 23 as shown in FIG.

Then, in the image processing apparatus 22, for example, based on an image signal as shown on the monitor 23 in FIG. 1, first, the dimensions relating to the pitch P between the adjacent leads 3 and 3, P ₁ and P. ₂ ... Pn is obtained by the processing as shown in FIG.

That is, as shown in FIG. 2A, of the image signals from the camera 21, a specific horizontal scanning line signal SX is extracted in the image signal for the lead 3.

Next, as shown in FIG. 2B, a brightness level signal forming process is executed for the horizontal scanning line signal SX. At this time, if the surface of the lead 3 has a scratch 7 as shown in FIG.
Since the reflection state of the illumination light changes at the scratch 7, as shown in FIG. 2B, the brightness level signals B ₁ , B ₂ , B ₃ ... The noise signal N due to the scratch 7 is present.

Subsequently, the light-dark change point detection processing is executed, and the light-dark change point signal (c) is created as shown in FIG. 2 (c). Then, the center positions X ₁ , X _2, ... Xn corresponding to the centers of the leads 3 are respectively measured by obtaining the center position between the light and dark change points.

When measuring the center position of the lead 3,
First, the left and right edge positions of the lead 3 are obtained by signal processing. That is, the brightness level signals B ₁ , B ₂ , B ₃ ... Of the leads 3 shown in FIG. 2B are differentiated to generate the light-dark change point signal (c). At this time, as shown in FIG. 2B, since the brightness level signals B ₁ , B ₂ , and B _{3 of the} leads 3 include the noise signal N due to the scratch 7, (C)
As shown in FIG. 4, the noise differential signal NC due to the noise signal N is formed in the differential signal of the lead 3.
In the image processing apparatus, this noise differential signal NC group is also recognized as a signal candidate representing the edge of the lead 3, so that it becomes impossible to specify the left and right edges of each lead 3.

Therefore, in the lead measuring method according to the present embodiment, the following signal processing is carried out.

First, the QFP / IC to be inspected
The positions of the left and right edges of each lead 3 in the QFP / IC1 to be inspected are predicted based on the design data of the device 1 itself and the actual measurement data before being inspected by this inspection device. , Are input to the image processing device 22 by the predicted edge position input device 26.

Now, for example, the signal processing for the first lead 3 at the left end shown in FIG. 2C will be described. The image processing device 22 detects the differential signals XL ₁ and XR ₁ from the left and right positions DL ₁ and DR ₁ slightly outside the predicted edge position of the first lead 3 by the left and right edges 3L and 3R of the first lead 3. Then, the specified processing is performed.

That is, the left edge 3L of the first lead 3
When specifying, the differential signal is detected from the outer position DL ₁ predicted to the left of the actual left edge 3L to the right, and the differential signal X detected first is detected.
L ₁ is identified as the differential signal due to the left edge. In this case, the area from the beginning of the detection to the first detection of the differential signal XL ₁ is the background outside the first lead 3, which is determined by the prediction of the edge position. There is no possibility that the differentiated signal XL ₁ to be generated is the noise differentiated signal NC due to the scratch 7 on the first lead 3. Therefore, the position of the left edge 3L of the lead 3 is accurately specified regardless of the presence of the noise differential signal NC due to the scratch 7.

Similarly, when the right edge 3R of the first lead 3 is specified, a process of detecting a differential signal from the outer position DR on the right side of the actual right edge 3R to the left is carried out, and the right edge 3R is detected. The differential signal XR _{1 according to} is specified.

When the left and right edge positions of each lead 3 are specified in this way, the center positions X ₁ , X ₂ , X ₃ ... X _n of each lead 3 can be calculated by the following equation. it can. Xn = (XLn + XRn) / 2 ...

The center position of each lead 3 measured in this way is stored and then appropriately transmitted to the determination unit 24 in response to a command.

In the judging section 24, first, the pitch dimension P ₁ between the adjacent leads 3 and 3 corresponding to the intervals between the center positions X ₁ and X ₂ and X ₂ and X ₃ thus measured, P ₂ ... Pn are respectively calculated by the following equations. _{P 1 = X 2 -X 1,} P 2 = X 3 -X 2 ··· Pn = Xn-Xn -1 ···

Next, in the judging section 24, the actual measured values P ₁ , P ₂ ,.
..Pn and the set value Po transmitted from the setting unit 25
The difference between the lead 3 and each lead 3 is obtained by checking the difference between the lead 3 and the lead 3
It is determined whether the pitches P ₁ , P _2, ... Pn between them are proper or not.

That is, when the difference value of Pn-Po is within the allowable range, it is judged "good", and when the difference value of Pn-Po is outside the allowable range, it is judged "bad". Here, the set value Po and the allowable value are the QFP
It is preset in the setting unit 25 based on the standard dimensions of the IC1.

The determination result is output to an external device as needed. At this time, according to the present embodiment, it is possible to identify and instruct the lead of the defective portion and the error value thereof, and therefore, in the case where the defective portion is repeatedly output, the work of finding the cause of the defective portion can be performed. Can be speeded up.

By the way, as shown in FIG. 3A, when all of the leads 3 are bent in parallel in one direction, it is judged as defective according to the method of inspecting good / bad judgment based on the measurement of the pitch. I can't judge. That is, in such a case, the inspection method based on the measurement of the pitch cannot perform the inspection.

Therefore, in the present embodiment, as shown in FIG. 3, the following signal processing is performed on the lead 3 group based on the upper and lower horizontal scanning line signals SXu and SXd.

Based on the upper horizontal scanning line signal SXu,
The brightness level signal shown in FIG. 3 (b) is formed. Further, the brightness level signal shown in FIG. 3C is formed based on the lower horizontal scanning line signal SXd which is separated from the upper scanning line by the distance ΔY. However, the noise signal due to the scratches 7 formed on the lead 3 can be substantially eliminated by the processing described with reference to FIG. 2, and thus is not shown in FIGS. 3B and 3C.

Next, although not described in detail, the center position X in the upper half of each lead 3 is calculated based on the signal shown in FIG. 3B by the processing described with reference to FIG.
u ₁ , Xu ₂ ... Xun are measured. Also, FIG.
The center positions Xd ₁ , Xd _2, ... Xdn in the lower half of each lead 3 are measured based on the signal shown in FIG.

Then, the average value Q of the difference between the center positions Xu ₁ , Xu ₂ ... Xun in the upper half of each lead 3 and the center positions Xd ₁ , Xd ₂ ... Xdn in the lower half is calculated by the following equation. Desired. Q = _{[(Xu 1 -Xd 1) + (} Xu 2 -Xd 2) ··· + (Xun-Xdn) ] / N ···

Further, based on this average value Q, the tan of the parallel bending inclination angle θ of the lead 3 group can be obtained by the following equation. tan θ = Q / ΔY ...

Next, in the judging section 24, the difference between the value of tan θ relating to the tilt angle thus obtained and the set value tan θ ₀ transmitted from the setting section 25 is found, and the magnitude of the difference is found. By checking whether or not the allowable value is within the range, it is determined whether or not the lead group 3 has a parallel bend.

Next, the determination of the flatness of the lead 3 will be described with reference to FIG.

Here, the brightness level of the image signal at the tip cutting surface 8 and the bent portion of the lead 3 formed in the gull wing shape becomes irregular. Therefore, it becomes difficult to measure the positions of the upper edge and the lower edge of the tip of the lead 3. On the other hand, the brightness of the reference surface 15 and the background (package 2) of the table 11 can be stably recognized from the image signal.

Now, the first lead 3B shown in (a)
The brightness level signal of the vertical scanning line signal Zb of
As shown in (b), next to the second lead 3D
The brightness level signal of the vertical scanning line signal Zc of
It is assumed that it is as shown in (d). On the other hand, the brightness level signal of the area formed by the background without the lead 3 and the reference plane 15 is always as shown in (c).

Therefore, (b) for the first lead 3B
When the reference signal of (c) is subtracted from the signal of, the signal shown in (e) is obtained. Further, when the reference signal of (c) is subtracted from the signal of (d) for the second lead 3D, the signal shown in (f) is obtained. As a result, a brightness level signal for the tip surface 8 of the lead 3 can be obtained regardless of whether or not the lead 3 is in contact with the reference surface 15.

Next, the brightness level signal (e) for the first lead 3B is differentiated to create the differential absolute value signal shown in (g). Then, the differential signal is started to be detected from the position where the signal component of the reference surface 15 was present, and the first detected differential signal is recognized as the edge Y ₁ of the tip of the lead 3 on the reference surface 15 side. Further, the differential absolute value signal shown in (i) is created by differentiating the brightness level signal (f) for the second lead 3D. Then, the differential signal is started to be detected from the position where the signal component of the reference surface 15 exists, and the first detected differential signal is recognized as the edge Y ₂ on the reference surface 15 side of the tip of the lead 3 where the lead 3 floats.

The position of the reference surface 15 is differentiated from the signal (c) to create a differential absolute value signal (h), and the detection is started from the background side or the reference surface 15 side, whichever is a stable level side. Be identified.

In this way, the position Y of the reference plane 15
₀ and the positions of the lower edge of each lead 3 Y ₁ , Y ₂ ...
After Y _n is obtained, the lower edge positions Y ₁ , Y ₂
..The difference between Y _n and the position Y ₀ of the reference surface 15, that is, Y
_{When n} −Y ₀ is obtained, the amount h of the lead 3 floating from the reference surface 15 is calculated.

Therefore, in the judging section 24, the interval dimensions h ₁ , h _2, ...
The difference between n and the preset reference interval that is called from the setting unit 25 is obtained at every moment, and whether the difference value is in the range of the preset allowable value that is also called is instantly determined. As a result of the collation, it is determined whether or not each lead 3 is lifted from the mounting surface.

For example, in FIG. 1, since the fifth lead 3e from the left floats upward, h
_{Since 5} becomes larger than the allowable range, it is determined to be defective. The judgment result is output to an external device as needed,
At that time, the defective portion and its error value correspond to each lead.

Next, the measurement of the height position of the root of the lead 3 will be described with reference to FIG.

As shown in (a), the upper vertical scanning line signal SZu and the lower vertical scanning line signal S of the lead 3 are obtained.
Zd is set respectively, and a brightness level signal is created based on both signals SZu and SZd. For example, the upper vertical scanning line signal SZu is set to scan upward with the upper horizontal scanning line signal SXu of FIG. 3A as a starting point. The lower vertical scanning line signal SZd is
The lower horizontal scanning line signal SXd in FIG. 3A is set to start scanning downward.

The brightness level signal generated based on the upper vertical scanning line signal SZu is as shown in (b), and the brightness level signal generated based on the lower vertical scanning line signal SZd. Is as shown in (d). Further, the brightness level signal generated based on the vertical scanning line signal SZc passing through the background without the lead 3 and the reference plane 15 is as shown in (c).

Therefore, these signals (b), (c),
By performing the signal processing according to the processing described with reference to FIG. 4 by using (d), the position cn of the reference surface 15, the lower edge position dn of the lead tip, and the root position bn of the lead are Each is required.

The flatness of each lead 3 is calculated by the difference between the position cn of the reference surface 15 between the adjacent leads and the lower edge position dn of the tip of the lead, that is, (dn-cn). .. The lead height is the difference between the lead root position bn and the position cn of the reference surface 15, that is, (b
n-cn), is calculated.

As in each of the above-described cases, the determination unit 24 determines whether the flatness and the root height of the lead thus obtained are good or bad.

In order to reduce the variation of the reference plane 15 and the influence of the inclination, the least squares method is applied to each measurement position on the reference plane 15 and then the above-mentioned calculation is executed. Good.

Thereafter, the rotary table 11 is sequentially rotated by 90 degrees, and the lead 3 group rows on the remaining 3 side surfaces are
The appearance inspection is performed by repeating the above-described operation. In this case, the imaging work and the subsequent image processing can be performed in parallel.

According to the above embodiment, the following effects can be obtained. By mounting an electronic device equipped with a surface mount type package on a reference surface, capturing an image of the lead group with an image capturing device, and processing the image signal,
Since it is possible to automatically measure the positional relationship between the leads of the electronic device before mounting in a state where the positional relationship between the leads is assumed when mounting the device, reliance on human work. This allows you to automatically perform lead measurement work.

Automating the external appearance inspection of the leads by executing the external appearance inspection on the circumferential bending and properness of the leads, and the vertical deformation based on the measurement result of the positional relationship of the leads. Therefore, it is possible to improve the quality and reliability of the electronic device that is the inspection object of the inspection, and it is possible to increase the mounting appropriate rate at the time of automatic mounting for the electronic device that has undergone this inspection.

By increasing the mounting appropriate rate of the electronic device during the automatic mounting by the above inspection, it is possible to promote the surface mounting type of the electronic device, and thus to provide a product that meets the demand for high-density mounting. You can

An electronic device provided with a surface mount package is placed on a reference surface, its lead group is imaged by an imaging device, and its image signal is processed, so that only an image from one direction is obtained. Since it is possible to simultaneously measure the positional relationship in the three directions of X (circumferential direction), Y (radial direction), and Z (vertical direction) of the lead, the measurement work time of the lead of the electronic device and the appearance inspection by it The time can be greatly reduced.

In the above description, the time is actually consumed only for the time required to capture one screen of the lead group row, and the subsequent image processing can be executed electrically. The measurement work time and the inspection work time can be further shortened by performing parallel processing with the imaging time and the loading / unloading time of the electronic device.

In the above description, the electronic device is placed on the reference surface, the lead group of the electronic device is imaged by the imaging device including the reference surface, and the edge of each lead is detected based on the image signal for this imaging. When measuring each position, extract one horizontal scanning line signal in the image signal for the lead, execute the detection processing of the light and dark change point for this scanning line signal, while predicting the left and right edge positions of the lead, The left and right edge positions of each lead can be measured by finding the change point closest to the right from the approximate left edge predicted position and the change point closest to the left from the approximate right edge predicted position. it can. In the above, the detection processing for the left edge and the right edge of the lead is executed from the outer side to the inner side of the lead, so that the noise signal due to the scratch existing in the lead is removed. Therefore, the left and right edges of the lead can be accurately measured without being affected by scratches in the lead or roughness of the cut surface.

Although the invention made by the present inventor has been specifically described based on the embodiments, the invention is not limited to the embodiments and various modifications can be made without departing from the scope of the invention. Needless to say.

For example, in the lead inspection apparatus and the lead measuring apparatus, the number of image pickup devices is not limited to one, and a plurality of image pickup devices are provided so that lead group rows on a plurality of side surfaces can be imaged at the same time. May be omitted.

Further, the concrete constitutions of the image pickup device, the table for positioning and holding the object to be inspected, the chuck, the image processing device, the monitor, the judging portion and the setting portion are not limited to the constitutions shown in the above-mentioned embodiment. It is desirable to appropriately select it in accordance with specific conditions such as the shape, structure, and size of the inspection object.

In the above-described embodiment, the case where the lead measuring apparatus is incorporated in the lead inspecting apparatus and used in the lead inspecting method has been described. However, the lead measuring apparatus according to the present invention can be used, for example, in an IC manufacturing process. It can be used for measuring the pitch of the leads, the amount of bending of the leads in the radial direction, the amount of lifting of the lead tips, and the like, and the application is not limited.

In the above description, the invention made by the present inventor is the field of application which is the background of the invention.
Although the case where the invention is applied to the IC lead inspection technology has been described, the invention is not limited to this, and is also applicable to other ICs including surface mount packages, lead inspection technology for electronic components and electronic equipment, and lead measurement technology in general. It is applicable to the lead inspection technology and the lead measurement technology of the electronic device having the insertion type external terminal such as the IC having the dual in-line package, if necessary. You can

[0084]

The effects obtained by the typical ones of the inventions disclosed in the present application will be briefly described as follows.

An electronic device provided with a surface mount type package is placed on a reference surface, and its lead group is picked up by an image pickup device and its image signal is processed, whereby each lead of the electronic device is processed. Since it is possible to automatically measure the positional relationship between each lead in the mounting state before mounting, assuming that the mounting position of the lead is measured, it is not necessary to rely on human work to measure the lead. Work can be performed automatically.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a lead inspection apparatus that is an embodiment of the present invention.

FIG. 2 is an explanatory diagram for explaining the action of measuring the pitch.

FIG. 3 is an explanatory diagram for explaining the action of measuring parallel bending of a lead group.

FIG. 4 is an explanatory diagram for explaining the action of measuring the floating of leads.

FIG. 5 is an explanatory diagram for explaining the action of measuring the flatness of the lead and the height of the root.

6A and 6B are a perspective view and a partially cut front view showing a mounted state of a QFP / IC.

[Explanation of symbols]

1 ... QFP / IC (electronic device, inspected object), 2 ... Package, 3 ... Lead, 4 ... Printed circuit board, 5 ... Land, 6 ... Solder layer, 7 ... Lead scratch, 8 ... Lead cut surface 10 ... Lead inspection device, 11 ... Rotary table,
12 ... Rotation drive device, 13 ... Suction chuck, 14 ... Negative pressure supply path, 15 ... Mirror surface, 16 ... Illumination device, 20 ... Lead measuring device, 21 ... Camera (imaging device), 22 ... Image processing device, 23 ... Monitor , 24 ... Judgment unit, 25 ... Setting unit, 26
... Edge predicted position input device.

Claims (8)

[Claims] 1. A lead measuring method for measuring a positional relationship of a lead group in an electronic device having a surface mount package, wherein the electronic device is placed on a reference plane, and the lead group of the electronic device is placed on the reference plane. A lead measuring method comprising: taking an image with an image pickup device including the above, and measuring an edge position of each lead based on an image signal of the image pickup. 2. One horizontal scanning line signal in the image signal for the lead is extracted, a process of detecting a light-dark change point is executed on the scanning line signal, and left and right edge positions of the lead are predicted, and The left and right edge positions of each lead are measured by finding the change point that is closest to the right from the approximate left edge predicted position and the change point that is closest to the left from the approximate right edge predicted position. The lead measuring method according to claim 1, wherein the lead measuring method is performed. 3. The pitch between each lead is obtained by calculating the center position of each lead from the left and right edges of each lead and calculating the interval dimension of the center position of each lead. 3. The lead measuring method according to claim 2, wherein the goodness and badness of the position of the lead in the circumferential direction is inspected by comparing with the set value that has been set. 4. A pair of upper and lower horizontal scanning line signals in the image signals of the upper part and the lower part of the lead are respectively extracted, and a light-dark change point detection process is executed for both of the scanning line signals. The left and right edges of the upper part of the lead and the left and right edges of the lower part of the lead are measured based on the light-dark change point signal, and the center position of the upper part of the lead is determined from the left and right edges of the upper part, and the center position of the lower part of the lead is determined from the left and right edges of the lower part. The lead measuring method according to claim 2, wherein the lead inclination angle is obtained from the upper and lower center positions. 5. A step of extracting one vertical scanning line signal in the image signal for the lead and creating a brightness level signal for this scanning line signal, and a step of generating a brightness level signal outside the lead and a reference surface. The vertical scanning signal in the image signal is extracted, and a brightness level signal is created for this vertical scanning line signal, and the brightness level signal of the reference plane is subtracted from the brightness level signal of the lead. And the light-dark change point formation process is performed on this subtraction signal, and the light-dark change point detection process is executed from the position where the brightness level signal corresponding to the reference plane existed, so that the lead reference The lead measuring method according to claim 1, wherein the surface-side edge is measured. 6. A vertical line signal in the image signal of the upper portion including the root of the lead is extracted, and a brightness level signal is created for the scanning line signal, and the brightness of the lead and the root is calculated. 6. The lead measuring method according to claim 5, wherein the brightness level signal of the reference surface is subtracted from the level signal, and the root position of the lead is measured based on the subtracted signal. 7. A lead measuring device for measuring a positional relationship between lead groups in an electronic device provided with a surface mount package, wherein the electronic device has a reference surface with which a mounting surface side of the lead group is brought into contact. A table to be held, an image pickup device for picking up an image of the lead group contacting the reference plane including the reference plane, and an image processing device for measuring the positional relationship between the lead groups based on an image signal of the image pickup device. A lead measuring device comprising: 8. A lead inspection apparatus for inspecting a positional relationship between lead groups in an electronic device including a surface mount package, wherein the electronic device has a reference surface with which a mounting surface side of the lead group is brought into contact. A table to be held, an image pickup device for picking up an image of the lead group contacting the reference plane including the reference plane, and an image processing device for measuring the positional relationship between the lead groups based on an image signal of the image pickup device. A determination unit that determines the pitch of each lead, the difference between the lead tip position and the reference plane position, and determines the positional relationship in the circumferential direction, the vertical direction, and the radial direction for each lead based on the measurement data of this image processing apparatus. A lead inspection device comprising: