JPH05215802A - Printed wiring board inspecting jig - Google Patents

Abstract

PURPOSE:To provide a printed wiring board inspecting jig which can cope with diametrical reduction and breakage prevention of a contact needle of a probe and by which a guide hole can be bored easily. CONSTITUTION:In an inspecting jig to inspect a highly densely pitched wiring circuit 71 on a printed wiring board 7 by means of the electrical continuity, the inspecting jig is composed of a contact pin 3 installed in a guide hole of a guide plate 8 so as to be slidably and a probe 1 fixed to a pin board 88. The probe 1 has a contact needle 2 installed inside of a socket 11 so as to be capable of approaching/retreating elastically. The contact needle 2 is brought into contact with a head part of the contact pin 3. In the case of inspecting a printed wiring board, the tip of the contact pin 3 is brought into contact with the wiring circuit 71, so that the electrical continuity can be inspected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a test jig for printed wiring boards, and more particularly, to a structure around a probe which exhibits an excellent effect on the inspection of high-density wiring circuits.

[0002]

2. Description of the Related Art As a method of inspecting a wiring circuit on a printed wiring board for the presence or absence of electrical continuity and its apparatus, various types have been proposed (for example, Japanese Patent Publication No.
No. 44035, JP-A No. 56-11060). As a conventional inspection jig for a printed wiring board, as shown in FIGS. 9 and 10, a stylus 92 of a probe 9 is brought into contact with a wiring circuit 75 of the printed wiring board 7. Is used to inspect for electrical continuity.

The inspection jig comprises a guide plate 8 for preventing rattling of the tip of the probe, a pin board 88 for holding the probe 9, and a probe 9 mounted by penetrating both. As shown in FIG. 10, the probe 9 has a pipe-shaped socket 91 and a stylus 92.
The socket 91 is inserted and fixed in the through hole 881 of the pin board 88. On the other hand, the stylus 92 is inserted into the guide hole 81 of the guide plate 8 so as to be movable back and forth. The stylus 92 has a plunger 920 on its upper part. The plunger 920 is mounted in the inner cavity of the tube 25 so as to be able to move forward and backward via a spring spring (not shown).

The upper end of the probe 9 is electrically connected to an inspection device for detecting electrical continuity. The guide plate 8 has a recess 82 for disposing the lower end of the socket 91. Further, the probe 9 is provided at a position corresponding to the wiring circuit 75 of the printed wiring board 7 as the inspection object. Further, the guide plate 8 and the pin board 88 are integrally fixed. When inspecting the electrical continuity of the wiring circuit, the guide plate 8 and the pin board 88 are lowered and raised from above and below the printed wiring board 7, and the stylus 92 of the probe 9 and the stylus pad of the wiring circuit 75 ( Abbreviated below). At this time, when the wiring circuit 75 is not broken or short-circuited, normal electrical conduction is obtained. As a result, the quality of each wiring circuit 75 can be determined.

Further, in the above, the tip 921 of the stylus 92 is
When contacting the wiring circuit 75, the stylus 92 retracts toward the socket 91 side along the guide hole 81 of the guide plate 8,
The plunger 920 penetrates into the socket 91.
This is to protect the tip 921 of the stylus 92.
In FIG. 9, reference numerals 87 and 886 are knock pins 8.
91 insertion holes, 871 and 885 are positioning pins 892.
It is the insertion hole.

[0006]

[Problems to be Solved] However, the conventional inspection jigs described above have the following problems. That is, in recent years, the density of wiring circuits in printed wiring boards has increased, and the pitch of the pads at the ends of the wiring circuits has become narrower.
For example, this pitch was conventionally about 0.65 mm, but in a high-density wiring circuit it is as narrow as 0.3 mm.

Therefore, in order to deal with this, the probe 9
Since it is necessary to narrow the array pitch of, it is necessary to reduce the size (diameter) of the probe itself. Also in the probe 9 currently used, the outer diameter of the socket 91 is about 1 mm, and the diameter of the probe 92 is as small as 0.5 mm. Further, in the conventional inspection jig, the tip 921 of the stylus 92 is brought into direct contact with the wiring circuit 75 in the inspection. Further, when the contact is made, the stylus 92 is moved to the guide hole 8 of the guide plate 8 as described above.
Slide inside 1 and move backward. Then, after the inspection, the stylus 92 is made to project again to its original position by the spring spring provided in the socket 91. Therefore, the stylus 9
2 slides in the guide hole 81 at each inspection.

Therefore, the stylus 92 is easily worn. Further, if the diameter of the guide hole 81 is increased to prevent this wear, the clearance between the stylus 92 and the stylus 92 becomes large, and the tip 921 of the stylus 92 may rattle, resulting in defective inspection. Further, the stylus 92 is inserted into a socket 91 fixed to the pin board 88. Therefore, the socket 91, the stylus 92, and the guide hole 81 must have the same axis. Therefore, in order to smoothly slide the small-diameter stylus 92, the guide hole 81 needs to be drilled with high dimensional accuracy so that the shaft cores coincide with each other.

The stylus 92 slides coaxially in the socket 91 and the guide hole 81, and the tip 921 of the stylus 92 directly contacts the wiring circuit 75. It is easily damaged. As described above, in the conventional inspection jig, as the wiring circuit becomes higher in density, there are problems particularly in the thinning and damage of the probe stylus 92 of the probe, the drilling accuracy of the guide hole 81, and the like. In view of such conventional problems, the present invention is to provide a test jig for a printed wiring board, which can cope with the thinning and damage prevention of the probe stylus, and which is easy to form a guide hole. is there.

[0010]

The present invention is an inspection jig for inspecting a wiring circuit in a printed wiring board according to the presence or absence of electrical continuity, the inspection jig including a guide plate, a pin board, and the wiring circuit. The probe comprises a contact pin for making contact with the probe and a probe having a stylus for making contact with the contact pin, and the contact pin is mounted on the guide plate so as to be movable back and forth. An inspection jig for a printed wiring board is characterized in that it is built in so as to be elastically movable back and forth. What is most noticeable in the present invention is that the probe of the above-mentioned conventional example is divided into, so to speak, two sets to form a contact pin and a probe, and the contact pin is brought into contact with a wiring circuit, while the probe of the probe is That is, it is configured to be brought into contact with the contact pin.

That is, contact pins are attached to the guide plate facing the printed wiring board so as to be able to move back and forth, and the probe is fixed to the pin board facing the guide plate. And
The probe has a stylus built in the socket so as to be elastically movable back and forth. As described above, as a means for incorporating the stylus in the socket, there is a means for elastically holding the stylus in the tube and mounting these in the socket (see FIGS. 4 and 5). There is also a means for elastically holding a direct contact needle by inserting it into the socket. There is a spring spring as the elastically holding means.

Further, the contact pin is mounted in the guide hole of the guide plate so as to be able to move forward and backward. The contact pin has a tip that abuts on the wiring circuit, and an abutting portion that abuts the stylus on the opposite side. The abutting portion preferably has a head portion having a larger diameter than the main body of the contact pin. Further, it is preferable to provide a curved surface concave portion at the contact portion to ensure contact of the stylus (see FIG. 6). In addition, in the inspection jig of the present invention, the guide pin and the pin board are provided with the contact pins and the probe having the above-mentioned configuration according to the present invention, and the above-mentioned conventional method is used to inspect a portion where the wiring circuit of the printed wiring board is not high density. It is also possible to install a probe pin having a relatively large diameter similar to the example.

[0013]

In the inspection jig of the present invention, contact pins are provided on the guide plate and probes are provided on the pin board.
The contact pin is brought into contact with the wiring circuit of the printed wiring board, and the stylus of the probe is brought into contact with the contact pin. That is, in the present invention, a portion (contact pin) that slides in the guide hole and comes into contact with the wiring circuit and a probe that is a detection end of electrical conduction are divided into two parts. Therefore, the contact pin advance / retreat and the probe stylus advance / retreat are independent.
Therefore, it is necessary to precisely match the three axes of the probe fixed to the pin board, the stylus inserted therein, and the guide hole of the guide plate through which the stylus advances and retracts, as in the conventional case. Absent.

Therefore, the precision of drilling the shaft center of the guide hole is not required to be high as in the conventional case, and the drilling is easy. Further, since it is sufficient that only the contact pin can be smoothly slid in the guide hole, it is possible to provide the guide hole with a small diameter and reduce the rattling of the contact pin. Further, when the contact pin is worn, it can be replaced easily and at low cost. Moreover, since the probe is not directly brought into contact with the wiring circuit, it is not damaged as in the conventional case. Also, the contact pin is
Although it directly contacts the wiring circuit and slides in the guide hole, it does not move back and forth in a straight line in both the guide hole and the socket of the probe like the stylus of a conventional probe. Never receive.

Further, as described above, since the contact pin and the probe are separately configured so as to prevent the forward movement and the backward movement of both of them at the time of inspection, both of them can be thinned. Therefore, it is easy to inspect high-density wiring circuits. Moreover, the probe is elastically mounted in a socket having a small inner diameter of 0.1 to 0.3 mm so as to be able to move forward and backward. Therefore, although it is an expensive precision part, it is not damaged as described above, so the cost of the inspection jig is also low. Therefore, according to the present invention, it is possible to provide an inspection jig for a printed wiring board, which can cope with the thinning of the probe stylus and the prevention of damage, and which can easily form a guide hole.

[0016]

EXAMPLE An inspection jig for a printed wiring board according to an example of the present invention will be described with reference to FIGS. As shown in FIGS. 1 to 3, the inspection jig of this example includes a guide plate 8, a pin board 88, a contact pin 3 for contacting the wiring circuit 71, and a contact pin 3 for contacting the contact pin 3. The probe 1 has a stylus 2 incorporated therein. Further, the contact pin 3 is mounted on the guide plate 8 so as to be movable back and forth, and the stylus 2 is built in the socket 11 of the probe 1 so as to be elastically movable forward and backward.

The wiring circuits 71 are arranged in high density on the printed wiring board 7. In the inspection jig of this example, the same probe 9 as the conventional one is attached to inspect the wiring circuit 75 having a large arrangement pitch. The guide plate 8 and the pin board 88 are detachably and integrally coupled by a knock pin 891 as in the conventional case. The guide plate 8 is shown in FIGS.
As shown in FIG. 3, the contact pin 3 has a large number of guide holes 85 for mounting it so that it can move forward and backward, and an opening groove 86.
The pin board 88 has a through hole 88 for inserting and fixing the socket 11 of the probe 1 as shown in FIGS.
Have two.

As shown in FIGS. 2, 3 and 6, the contact pin 3 has a tip 31 for contacting the wiring circuit 71 and a head for contacting the stylus 2. It has a part 32. In addition, the head 32 has a curved concave portion 321.
(FIG. 6). As shown in FIGS. 2 to 5, the probe 1 is composed of a socket 11 and a stylus 2 which is inserted into the socket 11 so as to be movable back and forth. As shown in FIG. 4, the socket 11 is a hollow pipe and has a flange 11 on the insertion side of the stylus 2.
Has 0. Further, the lead wire 15 connected to the inspection device 18 (FIG. 1) is provided on the upper portion.

On the other hand, the stylus 2 is mounted in a tube 25 so as to be movable back and forth, as shown in FIGS. That is, as shown in FIG. 5, the stylus 2 has a guide column 22 having substantially the same diameter as that of the stylus 2, and a thin connecting portion 21 between the two. Then, the spring 25 is first put in the tube 25, and then the stylus 2 is inserted. Then, the tube 25 is caulked at the outer side of the connecting portion 21 of the stylus to form the caulked portion 251. .

As a result, the stylus 2 is elastically mounted in the tube 25 by the spring spring 23 so as to be able to move forward and backward. The reference numeral 252 indicates the tube 25.
Is a caulking portion provided at the upper end of the spring for contacting the upper end of the spring spring 23. Then, the stylus 2 thus configured is inserted into the hollow portion 111 of the socket 11 as shown in FIG. At this time, the upper end of the tube 25 holding the stylus 2 has the caulked portion 113 of the socket 11.
Abut. Further, the probe 1 configured as described above
Is inserted into and fixed in the through hole 882 of the pin board 88 as shown in FIGS. Others are the same as in the conventional example.

Next, the function and effect will be described. That is, when inspecting the quality of the wiring circuit 71 on the printed wiring board 7 by electrical conduction, as shown in FIGS. 1 to 3, the guide plate 8 and the pin board 88 are approached to each wiring circuit 71 from above and below. Then, the guide plate 8 faces the printed wiring board 7. At this time, before the contact between the two, the contact pin 3 is in a state of protruding from the guide plate 8 as shown in FIG. Further, the head 32 of the contact pin 3 is in contact with the tip 21 of the stylus 2 of the probe 1.

When the guide plate 8 contacts the printed wiring board 7 and the tip 31 of the contact pin 3 contacts the wiring circuit 71, the contact pin 3 slides up in the guide hole 85. Then, as shown in FIG. 3, the tip 31 of the contact pin is located at substantially the same position as the lower surface of the guide plate 8. At this time, the head 32 of the contact pin 3 is
The stylus 2 is pressed toward the probe 1. Therefore, the stylus 2 enters the tube 25 against the biasing force of the spring spring 23 (FIG. 5).

In this way, the tip 31 of the contact pin 3 is
However, after contacting the wiring circuit 71, the lead wire 15
A current is passed through the probe 1, the stylus 2, and the contact pin 3 to determine whether the wiring circuit 71 is good or bad (FIG. 1). After the inspection, the guide plate 8 and the like are moved away from the printed wiring board 7. Therefore, contact pin 3
2 by the effort of attaching the spring spring 23 of the stylus 2.
As shown in. The conventional probe 9 shown in FIG. 1 operates similarly to the conventional example. As described above, in the inspection jig of this example, the contact pin 3 is mounted on the guide plate 8 so as to be movable back and forth, and the probe 1 is fixed to the pin board 88 and the stylus 2 is movable so as to move back and forth inside the probe 1. I am wearing it.

Therefore, the forward / backward movement of the contact pin 3 and the forward / backward movement of the stylus are independent of each other. Therefore, as in the prior art, the three axes of the probe 1 fixed to the pin board 88, the stylus 2 inserted therein, and the guide hole 85 of the guide plate through which the stylus advances and retracts are matched with high accuracy. You don't have to let me. That is, in this example, even if the axial center of the contact pin 3 and the axial center of the stylus 2 are misaligned, there is no problem as long as they are in contact with each other (FIGS. 2 and 3). Therefore, high precision is not required for the drilling accuracy of the guide hole 85 of the guide plate 8 and the axis of the hole of the pin board 8, and the drilling is easy. Further, since the guide hole 85 only needs to be able to smoothly slide the contact pin 3, it can be provided with a small diameter and is free from rattling.

Further, since the probe 1 does not directly contact the stylus 2 with the wiring circuit 71, it is not damaged as in the conventional case. Further, the contact pin 3 directly abuts on the wiring circuit 71 and slides in the guide hole 85. However, like the stylus of the conventional probe, the contact pin 3 must be linearly advanced and retracted both in the guide hole 85 and the probe socket. There is no. Therefore, there is no damage due to axial misalignment between the two.

Further, since the contact pin 3 and the probe 1 are separately configured so as not to cause an unreasonable advance and retreat of both of them at the time of inspection, both of them can be thinned. In this example, the diameter of the contact pin 3 is 0.27 mm, and the outer diameter of the socket of the probe 1 is 0.45 mm.
mm, inner diameter is 0.27 mm, outer diameter of stylus 2 is 0.15 m
m. In addition, in the contact pin 3 of this example,
Since the curved portion 321 is provided on the head 32, the head 3
The tip 20 of the stylus 2 can be reliably brought into contact with the needle 2.

[Brief description of drawings]

FIG. 1 is an overall explanatory view of an inspection jig according to a first embodiment.

FIG. 2 is a cross-sectional view around contact pins and a printed wiring board in a state before inspection according to the first embodiment.

FIG. 3 is a cross-sectional view around contact pins and a printed wiring board at the time of inspection in the first embodiment.

FIG. 4 is a developed front view of a socket and a stylus in the probe of the first embodiment.

FIG. 5 is a cross-sectional view of the tip portion of the probe in the first embodiment.

FIG. 6 is a front view of the contact pin according to the first embodiment.

FIG. 7 is a plan view of the guide plate according to the first embodiment.

8 is a cross-sectional view taken along the line AA of FIG.

FIG. 9 is an overall explanatory view of an inspection jig in a conventional example.

FIG. 10 is an explanatory view around the probe of the inspection jig in the conventional example.

[Explanation of symbols]

 1. ． ． Probe, 11. ． ． Socket, 15. ． ． Lead wire, 18. ． ． Inspector, 2. ． ． Stylus, 23. ． ． Spring, 25. ． ． Tube, 3. ． ． Contact pin, 31. ． ． Tip, 7. ． ． Printed wiring board, 71. ． ． High-density pitch wiring circuit, 75. ． ． 7. Wiring circuit with normal wiring pitch, 8. ． ． Guide plate, 85. ． ． Guide hole, 88. ． ． Pin board,

[Procedure amendment]

[Submission date] August 11, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction content]

[0013]

In the inspection jig of the present invention, contact pins are provided on the guide plate and probes are provided on the pin board.
The contact pin is brought into contact with the wiring circuit of the printed wiring board, and the stylus of the probe is brought into contact with the contact pin. That is, in the present invention, a portion (contact pin) that slides in the guide hole and comes into contact with the wiring circuit and a probe that is a detection end of electrical conduction are divided into two parts. Therefore, the contact pin advance / retreat and the probe stylus advance / retreat are independent.
Therefore, a probe fixed to pin onboard a stylus inserted therein, the three axis of a guide plate of the guide hole in which the contact pin forward and backward, it is not necessary to match with high accuracy.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0014

[Correction method] Change

[Correction content]

Therefore, the drilling of the shaft center of the guide hole is
It suffices if the holes are drilled to match the wiring circuit of the printed wiring board.
In addition, it does not require high precision as in the past and is easy to drill. Further, since it is sufficient that only the contact pin can be smoothly slid in the guide hole, it is possible to provide the guide hole with a small diameter and reduce the rattling of the contact pin. Further, when the contact pin is worn, it can be replaced easily and at low cost. Moreover, since the probe is not directly brought into contact with the wiring circuit, it is not damaged as in the conventional case. Also, the contact pin is
Although it directly contacts the wiring circuit and slides in the guide hole, it does not move back and forth in a straight line in both the guide hole and the socket of the probe like the stylus of a conventional probe. Never receive.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0024

[Correction method] Change

[Correction content]

Therefore, the forward / backward movement of the contact pin 3 and the forward / backward movement of the stylus are independent of each other. Therefore, as in the prior art, the three axes of the probe 1 fixed to the pin board 88, the stylus 2 inserted therein, and the guide hole 85 of the guide plate through which the stylus advances and retracts are matched with high accuracy. You don't have to let me. That is, in this example, even if the axial center of the contact pin 3 and the axial center of the stylus 2 are misaligned, there is no problem as long as they are in contact with each other (FIGS. 2 and 3). Also, because of that,
Align the guide hole 85 with the wiring circuit on the printed wiring board.
It should be drilled. Therefore, drilling accuracy with the axis of the hole of the guide hole 85 and pin board 8 8 is not high precision is required, it is bored easily. Further, since the guide hole 85 only needs to be able to smoothly slide the contact pin 3, it can be provided with a small diameter and is free from rattling.

Claims (1)

[Claims] 1. An inspection jig for inspecting a wiring circuit in a printed wiring board according to the presence or absence of electrical continuity, the inspection jig including a guide plate, a pin board, and a contact for contacting the wiring circuit. The probe comprises a pin and a probe having a stylus for making contact with the contact pin, and the contact pin is mounted on the guide plate so as to be able to move forward and backward. An inspection jig for printed wiring boards, characterized by being built in as much as possible.