JPH07161789A - Lead check device of electronic part - Google Patents

Abstract

PURPOSE:To enable a lead check device to quickly make a very accurate check of deformation in the lead of an electronic part such as an IC or the like independent of errors in setting the electronic part on a check board. CONSTITUTION:A package-side electrode and a large number of lead-side electrodes 16 corresponding to IC leads 12 are formed on a check board 14 through a wiring printing means. The lead-side electrode 16 is composed of adjacent electrodes 16a and 16b separate from each other by a gap 16c, and an insulating film is formed on the surface of the check board 14 covering the electrodes 15, 16a, 16b, and their lead wire sections. Due to the presence of the lead-side electrode 16 and the gap 16c, change properties of an electrostatic capacitance to the position of the IC lead 12a are so set as to be flat in an allowable positioning error range of a mount mechanism which sets an IC on the check board 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic component lead inspection apparatus suitable for detecting a bending defect of a lead derived from a package of an electronic component such as an IC.

[0002]

2. Description of the Related Art When an electronic component such as an IC is mounted on a printed circuit board and soldered, if the IC lead is bent, the tip of the IC lead is lifted from the land of the printed circuit board or displaced from the land. Therefore, soldering failure is likely to occur. Therefore, in the IC mounting process, it is necessary to measure the bending state of the IC lead for each IC in advance to exclude defective products. In this case, IC
The allowable deformation amount of the lead is, for example, a value of several tens of μm or less for floating deformation, and therefore, highly accurate measurement is required.

As an IC lead inspection apparatus used for such an application, there is one using an optical displacement sensor as described in, for example, Japanese Patent Laid-Open No. 4-15507. In this configuration, a light beam is emitted from the displacement sensor to the tip of the IC lead, and the reflected light is received by a photoelectric conversion element to measure the distance from the IC lead based on the angle of the reflected light. Is. If the IC lead is bent and deformed, the distance between the displacement sensor and the IC lead is different from the reference value, so that it can be detected.

However, in the inspection apparatus having the above structure, since the displacement sensor uses an extremely thin light beam, one IC is used.
In order to measure the bending deformation of all the IC leads of the chip, it is necessary to mechanically move the optical displacement sensor to sequentially irradiate the tip of each IC lead with the light beam. For this reason, a mechanical feed mechanism for sequentially feeding the optical displacement sensor in the arrangement direction of the IC leads is required, and as a result, the deformation detection accuracy of each IC lead is restricted by the accuracy of the feed mechanism. However, there is a problem in that sufficient accuracy may not be obtained, and it takes a relatively long time to measure all IC leads.

On the other hand, the following structure is also provided as a structure that can eliminate the need for a mechanical feeding mechanism. This is because two linear light sources are provided above and to the left of the IC lead group, and collimated rays are emitted toward the IC lead group in directions orthogonal to each other, and the light is emitted to the lower and right sides of the IC lead group. The light is received by a line sensor such as a CCD provided on one side. In this configuration, the light from the linear light source is incident on the line sensor, and at that time, a shadow is generated in a portion corresponding to each IC lead. Therefore, the position and size of the shadow when there is no bending deformation in each IC lead is determined. If you memorize it, depending on the position and size of the shadow of the IC lead of the IC to be inspected,
The bending deformation of the lead can be detected.

[0006]

However, in the above-mentioned inspection apparatus, since the line light source and the line sensor have to be positioned above, below, to the left and right of the IC, there is a drawback that the inspection apparatus as a whole becomes large. Moreover, the IC becomes large and the IC
If the lead group becomes long, the line light source must be made long in accordance with this, which makes it difficult to secure the parallelism of the inspection light beam, which eventually causes a decrease in measurement accuracy.

Further, since the IC is placed on the printed circuit board during soldering, each IC lead is bent by the self-weight of the IC, albeit slightly. However, in the above-described conventional inspection device, the IC is structurally measured in a state of being floated in the air, and therefore, the measurement is performed in a state different from the state at the time of soldering, and accurate measurement is performed. There are times when I can't forget.

Therefore, the present applicant has already developed and applied for an IC lead inspection device capable of detecting the deformation of the IC lead by measuring the electrostatic capacitance (for example, Japanese Patent Application No. 4-213489).
issue). This is because a large number of electrodes corresponding to each IC lead of the IC to be inspected are formed on the inspection board, and
The configuration is such that the electrostatic capacitance between the lead and each electrode is measured. When the IC lead is deformed such as lifted up, the IC lead is lifted up from the electrode of the inspection board, and the electrostatic capacitance is reduced. Is compared with a reference value, and when the measured capacitance is smaller than the reference value, it is determined that the IC lead has a bending deformation. According to this, when the IC lead is bent and lifted up from the electrode, the bend can be electronically detected, and therefore the IC lead can be quickly and accurately inspected. This has the excellent advantage that the inspection apparatus as a whole can be made compact.

However, on the other hand, it is inevitable that the mounting mechanism for setting the IC on the inspection substrate has some positioning error. Therefore, if the mounting mechanism causes the IC lead to be laterally displaced from the electrode, If is set on the inspection substrate, the capacitance between the IC lead and the electrode is reduced by the amount of the deviation. To explain this situation in detail, if the lead-side electrode 1 and the lead 2 of the electronic component have a relationship as shown in FIG.
The variation characteristic of the capacitance C with respect to the position x of the lead 2 with respect to the electrode 1 in the displacement direction shows the maximum value when the lead 2 corresponds to the center of the electrode 1 as shown by the solid line in FIG.
The larger the “deviation amount” from the center, the more rapidly the capacitance tends to decrease. Under such a change characteristic, if the electronic component is set off the center of the electrode 1 due to a positioning error of the mount mechanism, the "deviation amount"
Since the capacitance decreases in accordance with the above, the measured capacitance may fall below the reference value depending on the “deviation amount”.
There is a possibility that it may be determined that the IC lead is deformed although the C lead is not lifted and deformed.

The present invention has been made in view of the above circumstances. Therefore, it goes without saying that the inspection apparatus as a whole can be made compact while inspecting the deformation of the leads of electronic parts such as ICs at high speed and accurately. An object of the present invention is to provide a lead inspection device for an electronic component, which can perform an inspection accurately regardless of a positioning error of a mount mechanism for setting the electronic component on an inspection board.

[0011]

In order to achieve the above object, in the lead inspection apparatus of the present invention, an electronic component to be inspected is placed at a predetermined position on an inspection board by a mounting mechanism and is led out from the electronic component. And a lead-side electrode facing the lead drawn out from the package of the electronic component, which is provided on the inspection board, and formed on the inspection board to cover the lead-side electrode. And an insulating film, and a capacitance measuring means for measuring the electrostatic capacitance between the lead and each lead-side electrode when the lead faces the lead-side electrode through the insulating film. A state determination means for determining the state of the lead based on the capacitance, and the change characteristic of the capacitance with respect to the position of the lead is at least within the positioning error of the mounting mechanism. Characterized in was set to have a flat characteristic with respect to the position (the invention of claim 1).

Further, the inspection board is provided with a package side electrode corresponding to the package of the electronic component, and the capacitance between the lead and the lead side electrode is based on the capacitance between the package side electrode and each lead side electrode. It is also possible to adopt a configuration in which the measurement is performed (the invention of claim 2).

Further, in order to set the change characteristic of the combined capacitance with respect to the lead position so as to have the flat characteristic with respect to the lead position at least within the positioning error of the mounting mechanism, the predetermined position of the lead side electrode. A gap may be provided in (invention of claim 3), or
An auxiliary electrode having the same polarity as the lead of the electronic component may be provided near the lead-side electrode (the invention of claim 4).

[0014]

In the configuration of the present invention, in order to inspect the leads of the electronic component, the electronic component to be inspected is set on the inspection substrate by the mounting mechanism, and the leads are attached to the plurality of lead side electrodes through the insulating film. The two are facing each other. At this time, if the lead is bent and deformed so as to float from the lead-side electrode, the capacitance between the lead and the lead-side electrode becomes smaller than that when the lead is not bent. Therefore, when the capacitance measured by the capacitance measuring means is smaller than the reference value, the state determining means determines that the lead is bent and deformed.

In this case, according to the present invention, since the lead side electrode is covered with the insulating film, the capacitance between the lead and the lead side electrode can be increased in accordance with the relative dielectric constant, and the measurement accuracy can be increased. Further, the leads can be placed on the lead side electrodes in an electrically non-contact state, so that the leads can be inspected in a state close to the mounted state of the electronic component.

That is, if it is attempted to measure the capacitance without an insulating film, the leads are lifted from the electrodes in order to prevent the leads from coming into contact with the lead-side electrodes and short-circuiting them. Must-have. Then, the distance between the electrode and the electrode must be set very accurately first, which causes difficulty in positioning in the direction of approaching the inspection board, and the error affects the measurement error of the air gap dimension. Become. Moreover, since the leads are lifted up in the air, the measurement is performed in a state different from the state at the time of soldering on the printed circuit board. On the other hand, in the configuration of the present invention, since it is sufficient to simply place the leads on the insulating film, there are few problems in setting the distance between the electrodes and the leads are in contact with the insulating film. The inspection can be performed in a state very close to the state when the electronic component is mounted.

Further, even if the electronic component is not set at the proper position due to the positioning error of the mounting mechanism, in the present invention, the change characteristic of the capacitance with respect to the position of the lead is within the range of the positioning error of the mounting mechanism. Since it is set to have a flat characteristic with respect to the position of the lead, the capacitance hardly changes depending on it, so it is not possible to mistakenly judge that the lead has bending deformation. Absent. That is, for example, when the lead-side electrode 1 is divided into two electrodes 1a and 1b with a gap 1c between them as shown in FIG. 2A, the capacitance change characteristic due to the presence of the gap 1C is shown in FIG. As indicated by the solid line in B), the flatness characteristics are lowered. Then, even if the lead 2 is set to be displaced from the center of the lead-side electrode 1 due to a positioning error of the mount mechanism, the capacitance is hardly reduced due to that, and malfunction is prevented.

In order to measure the combined electrostatic capacitance between the lead and the lead-side electrode, it is not limited to directly applying a voltage to the lead and the lead-side electrode and measuring the flowing current. As in the invention, the capacitance between the package side electrode and the lead side electrode provided on the inspection substrate can be measured. In this case, the combined capacitance of the capacitance between the portion of the lead located inside the package of the electronic component and the package side electrode and the capacitance between the lead side electrode of the lead is measured. However, the former is a fixed value that is not affected by bending deformation of the lead, so the latter can be easily calculated. Further, as in the invention of claim 4, when the auxiliary electrode is provided in the vicinity of the lead-side electrode so that the auxiliary electrode has a polarity opposite to that of the lead-side electrode, the change in the capacitance is changed as compared with the case where the gap is simply provided. The characteristics can be changed in a wider range.

[0019]

As described above, according to the inspection apparatus of the present invention,
Since the capacitance is measured and the deformation of the lead is inspected, the inspection can be speeded up and the accuracy can be improved, and the inspection device as a whole can be configured in a small size. And get the proper test result,
Furthermore, even if there is a positioning error in the mounting mechanism,
It has an excellent effect that an accurate inspection can be performed without being affected by the influence. Further, according to the invention of claim 2 in which the package-side electrode is provided, there is an effect that the capacitance between the lead and the lead-side electrode can be easily measured.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to an IC lead inspection apparatus will be described below with reference to FIGS.

First, the IC to be inspected in this embodiment will be briefly described. This is as shown in FIG.
A large number of IC leads 12 (only one is shown) are drawn out in a row from the side of the package 11. The tip of each IC lead 12 is a flat part that is soldered to a land of a printed circuit board (not shown). 12a and IC
The base end side of the lead 12 has a well-known configuration that is continuous with the in-package conductor portion 12b located in the IC package 11. In this embodiment, the IC lead 12 has a width WIC (see FIG. 4) of 300 μm, a thickness of 100 μm, and a flat portion 12a having a length L of 800 μm. This I
In order to assemble the product by mounting C13 on a printed circuit board (not shown), the IC package 11 is sucked and conveyed by, for example, a suction device of an assembly robot (not shown).
The flat portion 12a of the C lead 12 is placed on the printed circuit board so as to come into contact with the land of the printed circuit board, and soldering is performed in this state. Before the IC is supplied to the suction device of the assembling robot, the IC 13 to be inspected by the mounting mechanism is set at a predetermined position on the inspection board 14 of this embodiment, and the IC leads 12 are bent and deformed. The presence or absence of is checked. Although not shown, the mount mechanism has a suction pad for vacuum suction at the tip of the arm, and has a well-known configuration for positioning and transporting the IC package 11 at a predetermined position on the inspection board 14 in a state where the suction pad sucks the IC package 11. In the example applied to this example, the positioning error was ± 100 μm.

Now, FIG. 3 also shows the electrode portion of the lead inspection apparatus of this embodiment. That is, the package side electrode 15 and a large number of lead side electrodes 16 corresponding to the IC leads 12 are formed on the inspection substrate 14 by the printed wiring means. Of these, the package side electrode 15 is formed in a frame shape corresponding to the outer periphery of the bottom surface of the IC package 11, and the lead side electrode 16 is a gap 16c.
The two electrodes 16a and 16b are adjacent to each other with the electrodes 16a and 16b in between, and each is formed in a rectangular shape extending in the extension direction of the IC lead 12. Although not shown for simplification of the drawing, the same number of pairs of electrodes 16 a and 16 b as the IC leads 12 are provided on the inspection substrate 14.
Like the group, they are arranged in rows. Furthermore,
As shown in FIG. 7, an insulating film 17 is formed on the surface of the inspection board 14.
Is formed, which covers the respective electrodes 15, 16a, 16b and the lead wire portions thereof. Here, the lead side electrodes 16a and 16b corresponding to each IC lead 12
More specifically, referring to FIG. 4, the width dimension W of each lead side electrode 16a, 16b is 80 μm, and the length dimension L is the same as that of the flat portion 12a of the IC lead 12 of 800 μm.
m, the gap distance G between the lead side electrodes 16a and 16b is 220 μm. Therefore, when the IC lead 12 is set at the center of both electrodes 16a and 16b, the outer edge portions of both electrodes 16a and 16b are located outside the left and right side edge portions of the IC lead 12.

A capacitance measuring circuit 20 corresponding to the capacitance measuring means and a state determining circuit 30 corresponding to the state determining means for each of the above electrode groups are constructed as shown in FIG. In the figure, the lead side electrode 16a or 16
The capacitance C between b and the package side electrode 15 is represented by one capacitor symbol for each lead side electrode 16a or 16b. The basic principle of the capacitance measuring circuit 20 of this embodiment is that the oscillator circuit 21 is connected to the lead side electrode 16a or 16
An alternating voltage having a predetermined frequency is applied between the electrode b and the package-side electrode 15, and the capacitance between the electrodes is measured based on the magnitude of the current flowing between the electrodes. One of the output lines of the oscillation circuit 21 is connected to the ground line, and the other is connected to the selection circuit 22. Selection circuit 2
Reference numeral 2 denotes a switch element 22a of one-circuit / two-contact type, the number of which corresponds to the number of electrode pairs of the lead side electrodes 16a and 16b (the number of IC leads 12). As shown in FIG. It is connected to each lead side electrode 16a, 16b. The selection circuit 22 is configured such that one of the lead side electrodes 16a or 16b is connected to the oscillation circuit 2 described above.
1 to the lead side electrodes 16a,
It has a function of grounding 16b to a ground line.

On the other hand, the package side electrode 15 is connected to the capacitance measuring circuit 20, and the capacitance C between the lead side electrode 16a or 16b and the package side electrode 15 is measured. An equivalent circuit relating to the capacitance C of each IC lead 12 when the IC 13 is placed on the inspection board 14 is as shown in FIG. In the figure,
C1 and C2 are capacitances between the lead side electrode 16a or 16b and the flat portion 12a of the IC lead 12, C3 is a capacitance between the in-package conductor portion 12b located inside the IC package 11 and the package side electrode 15, and C4. , C5 indicate the capacitance between the package side electrode 15 and the lead side electrodes 16a, 16b. Here, C4 and C5 are fixed values determined by the arrangement pattern of each electrode on the inspection substrate 14, and C4
3 is also a fixed value determined by the shape and the like of the in-package conductor portion 12b located inside the IC package 11. Each IC
Depending on the state of the lead 12 (bending, tilting, etc.), C1,
Only C2 changes, and the capacitance C between the lead side electrode 16a or 16b and the package side electrode 15 changes accordingly.

In order to measure the electrostatic capacitance C, the capacitance measuring circuit 20 in this embodiment, as shown in FIG. 5, has an operational amplifier 23, a bandpass filter 24, and an inverting amplification type.
The absolute value circuit 25 and the low pass filter 26 are provided. Here, when the AC voltage from the oscillation circuit 21 is applied to any one of the lead side electrodes 16a or 16b selected by the selection circuit 22, the entire space between the lead side electrode 16a or 16b and the package side electrode 15 is changed. A current corresponding to the electrostatic capacitance C of the current flows, which is the current-voltage conversion resistor 27.
Is converted into a voltage, which is amplified and becomes an output voltage of the operational amplifier 23. The capacitor 28 connected in parallel with the current-voltage conversion resistor 27 is for compensating for phase rotation due to stray capacitance between the input of the operational amplifier 23 and the ground line. The output voltage of the operational amplifier 23 passes through the bandpass filter 24, is double-wave rectified by the absolute value circuit 25, and is smoothed by the lowpass filter 26. Therefore, the capacitance measuring circuit 20 outputs a level corresponding to the electrostatic capacitance C. DC voltage is output. Since the cutoff frequency of the low-pass filter 26 affects the response frequency of the circuit, it is desirable that the cutoff frequency be set to a relatively large value when performing high-speed measurement. The band-pass filter 24 is preferably a solid filter such as a ceramic filter or the like, and is for removing internal noise of the operational amplifier 23 in the preceding stage and external noise picked up from the electrode group.

On the other hand, the state discriminating circuit 30 is also constructed as shown in FIG. 5, and the DC output voltage from the capacitance measuring circuit 20 is converted into a digital signal by the A / D converting circuit 31 and given to the arithmetic processing circuit 32. . In the arithmetic processing circuit 32, a digital value corresponding to a combined electrostatic capacitance (C1 + C2) between the lead side electrodes 16a and 16b of each IC lead 12 of the IC 13 to be inspected, and a reference value storage circuit 33. If the combined capacitance (C1 + C2) is judged to be smaller than the reference value CR0 as described later as a result of comparison with the reference value CR0 stored in the IC display, the output display circuit 34 reads the IC. In addition to displaying that the deformation has been discovered on 12 and displaying the number of the IC lead 12,
It is designed to output a defective signal. When a defective signal is output to at least one IC lead 12, the corresponding IC is excluded by an excluding mechanism (not shown) so that the IC is not attracted to the hand of the assembly robot. . In addition, the reference value storage circuit 3
As the reference value CR0 stored in 3, the value of the combined electrostatic capacitance (C1 + C2) when the non-defective product IC 13 is set at a predetermined position on the inspection board 14 is used.

Next, the operation of this embodiment will be described. In the above-described configuration, the IC to be inspected is adsorbed on the IC package 11 part by the adsorption device of the mounting mechanism (not shown), and a pair of lead side electrodes 16 formed by the IC lead 12 group.
The IC package 11 is positioned on the inspection board 14 so as to face the a and 16b and the package side electrode 15. In this case, the flat portion 12a of each IC lead 12 faces the lead-side electrodes 16a and 16b directly above the lead-side electrodes 16a and 16b with the insulating film 17 interposed therebetween. The capacitors C1 to C5 are formed as shown in the equivalent circuit of FIG.

When the IC is set in the predetermined position in this way, each switch element 22a of the selection circuit 22 is switched in response to a signal from the control circuit 40 of the inspection apparatus, and the lead side electrodes 16a, 16b are arranged in a predetermined order. Selectively enable one of the. As a result, the AC voltage from the oscillation circuit 21 is applied to the validated lead side electrode 16a or 16b, and the lead side electrode 16a or 16b is activated.
A current corresponding to the electrostatic capacitance C flows between the and the package-side electrode 15.

Here, the value of the capacitance C for each IC lead 12 differs depending on the state of the IC lead 12 and the set position of the IC lead 12. That is, there is no bending deformation in the IC leads 12, and each IC lead 12
Is set at the center of each lead-side electrode 16a, 16b, the flat portion 12a of each IC lead 12 is in contact with the insulating film 17 and the center of both lead-side electrodes 16a, 16b as shown in FIG. The capacitances C1 and C2 between the lead-side electrodes 16a and 16b and the flat portion 12a of the IC lead 12 have maximum values.

However, if one of the IC leads 12 is bent and deformed upward, as shown in FIG. 8, the flat portion 12a of the IC lead 12 and the insulating film 17 are formed.
Since an air gap is generated between the
Both C2 become smaller. Therefore, when the combined value (C1 + C2) of both capacitors C1 and C2 is smaller than the reference value CR0, it can be determined that the IC lead 12 is lifted from the inspection substrate 14. In this embodiment, a current having a value corresponding to the capacitance C between the lead side electrode 16a or 16b and the package side electrode 15 flows, and a voltage corresponding to the current value is output from the capacitance measuring circuit 20. Based on the above, the electrostatic capacitances C1 and C2 are calculated by the arithmetic processing circuit 32, and the combined electrostatic capacitance (C1 + C2) is calculated to obtain the reference value C.
Compared with R0. Since the capacitances C3 to C5 are fixed values, changes in the capacitances C1 and C2 can be easily derived by measuring the capacitance C, and further, both capacitances C1 and C2.
The combined value (C1 + C2) of can be easily obtained by simple addition. In this embodiment, the IC lead 1
If the combined value (C1 + C2) of both capacitances C1 and C2 for a part of the two groups is smaller than the reference value CR0, it is determined that the IC lead 12 has an upward bending deformation, and IC lead 1 based on the signal of
The number 2 is stored, and the IC 13 is excluded by an ejection mechanism (not shown).

By the way, in the present embodiment, the shapes of the lead side electrodes 16a and 16b are determined as shown in FIG. Under this electrode shape, the floating amount of the IC lead 12 is 50
The value of the combined capacitance (C1 + C2) and I in the case of μm
When the relationship with the “deviation amount” from the center position of the C lead 12 was actually measured, it was as shown by the solid line in FIG. That is, the range of positioning error of the mounting mechanism (± 100 μ
Within a range slightly exceeding m), the combined capacitance showed a substantially flat characteristic with respect to the “deviation amount” of the IC lead 12.
Therefore, due to the positioning error of the mounting mechanism, the IC1
Even if 3 is set off the center of each lead side electrode 16a, 16b, in this embodiment, the combined capacitance (C
1 + C2) hardly changes. Therefore, the mounting mechanism moves the IC 13 within the positioning error of both electrodes 1
Even if the IC leads 12 are set at positions deviated from the centers of 6a and 16b, the IC leads 12 will not be erroneously determined to be bent and deformed, and malfunctions can be reliably prevented. When some of the IC leads 12 are largely deformed in the lateral direction, the area facing the lead-side electrodes 16a and 16b is reduced, so that the combined electrostatic capacitance (C1 +
Since C2) becomes small, it is also detected as a bending defect. Further, after performing the bending inspection by the inspection device of this embodiment, another inspection using the image processing device or the like can be performed.

As described above, this embodiment has the following effects. The mechanical structure portion for inspecting the IC is only the inspection substrate 14 on which a large number of electrodes are formed, and the inspection portion is different from the conventional optical inspection device in which the line light source and the line sensor need to be combined in an opposed state. Can be remarkably miniaturized. Of course, the mechanical portion is simple and the size can be reduced as compared with the configuration in which the optical displacement sensor is mechanically moved by the feeding mechanism. The miniaturization of the inspection unit in this way means that it can be easily incorporated into the component mounting robot, which is a remarkable advantage. Further, in the present embodiment, the group of IC leads 12 is inspected one by one. For this purpose, each switch element 22a of the selection circuit 22 is sequentially switched to sequentially activate each lead side electrode 16a, 16b. Therefore, the switching can be performed at an extremely high speed, and the time required for the inspection can be greatly shortened as compared with the conventional configuration in which the IC lead groups are mechanically scanned one by one.

Further, generally, the purpose of this kind of inspection is to inspect the bending deformation of the IC lead which causes the defective soldering to the printed circuit board. Therefore, it is ideal that the IC be inspected in the soldered state. For example, depending on the direction of bending deformation, even if the amount of bending deformation is relatively large in the state of floating in the air, when it is mounted on the printed circuit board, the weight of the IC causes the IC
This is because the bending deformation of the leads may be repaired and the leads may adhere to the lands of the printed circuit board. However, in the conventional optical inspection device, the IC was measured in a state of floating in the air unlike the state of soldering. On the other hand, according to the inspection apparatus of the present embodiment, the IC is inspected while being mounted on the inspection board 14. Therefore, the group of IC leads 12 is measured in the same state as when soldering, so that the degree of bending deformation can be accurately measured.
It will best suit the purpose of the inspection.

Further, in the present invention, the change characteristic of the combined electrostatic capacitance (C1 + C2) with respect to the position of the IC lead 12 is set so as to have the flat characteristic with respect to the position of the IC lead 12 within the range of the positioning error of the mount mechanism. Therefore, even if there is a positioning error of the mounting mechanism, the measured combined capacitance hardly changes. Therefore, when the IC 13 is set on the inspection substrate 14 with a slight deviation due to the positioning error of the mounting mechanism. In addition, it is possible to reliably prevent the IC lead 12 from being erroneously determined to have a bending deformation. Moreover, since the fluctuation of the electrostatic capacitance due to such a positioning error is canceled by the skillful configuration of setting the combined electrostatic capacitance to have a flat characteristic, the structure is extremely simple, and the software is High-speed processing becomes possible compared to the ones that are dealt with in advance, which greatly contributes to speeding up the inspection.

Further, particularly in this embodiment, the package side electrode 15 is provided on the inspection substrate 14, and the package side electrode 1 is provided.
5 and the capacitance C between the lead side electrode 16a or 16b
Since the electrostatic capacitances C1 and C2 are measured based on the above, the electrostatic capacitances C1 and C2 are contactless to the IC lead 12.
C2 can be measured and the configuration for capacitance measurement is simplified.

Further, particularly in this embodiment, the lead side electrode 16a or 16 which is not activated in the selection circuit 22 is used.
Since b is configured to be grounded, the leakage current through the input-output capacitance can be minimized and the measurement error can be reduced accordingly.

<Other Embodiments> The present invention is not limited to the above-described embodiments, but can be modified and implemented as follows, for example.

(A) Various kinds of electronic parts can be applied as the electronic parts for inspecting the leads. For example, as shown in FIG. 11, a PLCC in which a large number of leads 62 are arranged in a rectangular package 61 having a recess 61a in the center. It may be applied to the lead inspection of the socket, and the point is that it can be widely applied to electronic parts in which leads are taken out from the package.

(B) In order to measure the electrostatic capacitance between the lead and the lead side electrode, for example, the lead is brought into contact with the electrode and the package side electrode 15 as in the above embodiment is not necessarily provided. The capacitance between the lead electrode and the lead-side electrode may be measured. Further, even when the package side electrode is provided, it is not always necessary to provide it on the inspection substrate as in the above-mentioned embodiment, and it may be provided on the suction device side of the mount mechanism, for example.

(C) In the above embodiment, the capacitance is measured for each of the two lead-side electrodes 16a and 16b, and the capacitance is measured by software to obtain the combined capacitance. However, the present invention is not limited to this. Instead, for example, as shown in FIG. 12, the lead-side electrodes 16a and 16b may be electrically connected at the lead wire portion 70 to obtain the combined capacitance all at once.
In this way, since it is not necessary to perform addition by software, it is possible to perform a higher speed inspection.

(D) Further, in order to flatten the change characteristic of the capacitance with respect to the position of the lead, the two electrodes 16a and 16b are not formed as in the above-described embodiment, but as shown in FIG. A single electrode 80 with a gap 81 in the center
May be provided to form an H shape. Further, as shown in FIG. 14, the center of the single electrode 82 may be recessed so that the central portion 83 is far from the lead.

(E) Further, as shown in FIG. 15, the two lead side electrodes 91, 92 are provided at the middle portion and the left and right side portions, respectively.
By providing the auxiliary electrode 93 having the same polarity as that of the lead of the electronic component, the change characteristic of the capacitance with respect to the position of the lead can be flattened.

(F) In the above embodiment, one oscillator circuit 21 is used.
Only the electrodes are provided so that the voltage is selectively applied to the lead-side electrodes 16a and 16b. However, an oscillator circuit is provided for each lead-side electrode, and these oscillator circuits are selectively enabled by a multiplexer. It may be configured.

(G) In the above embodiment, the reference capacitance CR0, which is compared with the combined capacitance (C1 + C2), is not limited to setting and measuring a non-defective IC and storing the value and using it.
You may input an appropriate value from a DIP switch etc., and may set it.

[Brief description of drawings]

FIG. 1 is a view for explaining a lead inspection apparatus of the present invention in comparison with other configurations, (A) is a perspective view, and (B) is a graph of capacitance.

2A and 2B are views for explaining the lead inspection apparatus of the present invention, in which FIG. 2A is a perspective view and FIG. 2B is a graph of capacitance.

FIG. 3 is a block diagram schematically showing an embodiment of the present invention.

FIG. 4 is a perspective view of an electrode portion of the embodiment.

FIG. 5 is an overall block diagram of an embodiment.

FIG. 6 is an equivalent circuit diagram showing capacitance.

FIG. 7 is an enlarged cross-sectional view of an IC lead portion showing a measurement situation of an example.

FIG. 8 is an enlarged cross-sectional view of an IC lead portion showing a measurement situation of an example.

FIG. 9 is an enlarged cross-sectional view of an IC lead portion showing a measurement situation of an example.

FIG. 10 is a graph showing a change characteristic of capacitance.

FIG. 11 is a cross-sectional view showing a PLCC socket as an inspection target.

FIG. 12 is a plan view of a lead electrode portion showing another embodiment.

FIG. 13 is a plan view of a lead electrode portion showing another embodiment.

FIG. 14 is a sectional view of a lead electrode portion showing another embodiment.

FIG. 15 is a plan view of a lead electrode portion showing another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... IC package 12 ... IC lead 13 ... IC (electronic component) 14 ... Inspection board 15 ... Package side electrode 16a, 16b ... Lead side electrode 16c ... Gap 17 ... Insulating film 20 ... Capacity measuring circuit 30 ... State discrimination circuit

Claims (4)

[Claims] 1. An electronic component to be inspected is mounted at a predetermined position on an inspection board by a mounting mechanism to inspect bending deformation of leads led out from the electronic component. A lead-side electrode that is provided and faces a lead derived from the package of the electronic component, an insulating film formed on the inspection substrate to cover the lead-side electrode, and the lead forms the insulating film on the lead-side electrode. Capacitance measuring means for measuring the capacitance between the lead and the lead-side electrode in a state of being opposed to each other, and a state determination for determining the state of the lead based on the measured capacitance. And a flat characteristic with respect to the position of the lead at least within a positioning error of the mounting mechanism. Electronic parts lead inspection apparatus characterized by being configured to have a. 2. An inspection board is provided with a package side electrode corresponding to a package of an electronic component, and a capacitance between the lead and the lead side electrode is measured by a static capacitance between the package side electrode and the lead side electrode. 2. The electronic component lead inspection apparatus according to claim 1, wherein the measurement is performed based on the capacitance. 3. The lead-side electrode is provided with a gap at a predetermined position so that the change characteristic of the capacitance with respect to the position of the lead is flat with respect to the position of the lead at least within the range of a positioning error of the mount mechanism. The lead inspection device for an electronic component according to claim 1 or 2, wherein the lead inspection device is set to have the following. 4. An auxiliary electrode having the same polarity as that of the lead side of an electronic component is provided near the lead side electrode so that the change characteristic of the capacitance with respect to the position of the lead is at least within the range of a positioning error of the mount mechanism. 3. The lead inspection device for an electronic component according to claim 1, wherein the lead position is set to have a flat characteristic with respect to the position of the lead.