JPH06180328A - Printed wiring board inspecting jig - Google Patents

Abstract

PURPOSE:To provide a printed wiring board inspecting jig which can cope with reductions in the diameter and arranging pitch of contact pins even when the density of a wiring circuit is increased. CONSTITUTION:The title jig is provided with contact pins 10 which are brought into contact with wiring circuits, stopper terminals connected to lead wires 15, and coil springs 20 which are interposed between the pins 10 and terminals 30 and push the pins 10 and terminals 30 outward. The housing of the jig is provided with guide plates 41 having guide holes 45 for mounting the pins 10, rear boards 43 having terminal holes 47 for housing the terminals 30, and main boards 42 having inserting holes 46 for housing the springs 20. In addition, intermediate members 50 are interposed between the pins 10 and springs 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed wiring board inspecting jig which exhibits an excellent effect particularly in inspecting a high-density wiring circuit.

[0002]

2. Description of the Related Art As a method for 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-56-11060). As a conventionally used printed wiring board inspection jig, as shown in FIGS. 6 and 7, the contact pin 92 of the probe 9 is brought into contact with the 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 through both of them. As shown in FIG. 7, the probe 9 has a pipe-shaped socket 91 and a contact pin 92. The socket 91 has a through hole 88 of the pin board 88.
It is inserted and fixed in 1.

On the other hand, the contact pin 92 is inserted into the guide hole 81 of the guide plate 8 so as to be movable back and forth. The contact pin 92 has a plunger 9 on its top.
Have twenty. The plunger 920 is a tube 25
It is mounted so as to be able to move forward and backward through a spring spring (not shown) in the inner cavity.

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 inspection pad of the wiring circuit 75 of the printed wiring board 7 as the inspection object. The guide plate 8 and the pin board 88 are integrally fixed by a knock pin 891.

When inspecting the electrical continuity of the wiring circuit, the guide plate 8 is placed from above and below the printed wiring board 7.
Also, the pin board 88 is lowered and raised to bring the contact pins 92 of the probe 9 into contact with the contact pin pads (hereinafter omitted) for inspection of the wiring circuit 75. 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, when the tip 921 of the contact pin 92 is brought into contact with the wiring circuit 75 in the above, the contact pin 92 retracts toward the socket 91 side along the guide hole 81 of the guide plate 8 and its plunger. 920 penetrates into the socket 91. This is to protect the tip 921 of the contact pin 92. In addition, in FIG.
Reference numerals 87 and 886 are insertion holes for the knock pin 891, and 87.
Reference numerals 1, 885 are insertion holes for the positioning pins 892.

[0008]

[Problems to be Solved] However, the above-described conventional inspection jig has 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 has been about 0.65 mm in the past, but is narrow in a high-density wiring circuit such as 0.2 to 0.3 mm.

Therefore, in order to deal with this, the probe 9
Since it is necessary to reduce the array pitch of, the size (diameter) of the probe itself must be reduced. Also in the probe 9 currently used, the outer diameter of the socket 91 is about 1 mm, and the contact pin 92
Has a small diameter of 0.5 mm. Further, in the conventional inspection jig, the tip 921 of the contact pin 92 is brought into direct contact with the wiring circuit 75 in the inspection.

When the contact is made, as described above,
The contact pin 92 slides in the guide hole 81 of the guide plate 8 and retracts. Then, after the inspection, the contact pin 92 is made to project again to the original position by the spring spring provided in the socket 91. Therefore, the contact pin 92 slides in the guide hole 81 and the socket 91 at each inspection.

Therefore, the contact pin 92 is easily worn. In order to prevent this wear, the diameter of the guide hole 81,
Further, if the inner diameter of the socket 91 is increased, the clearance between them becomes large. Therefore, the tip 921 of the contact pin 92 may rattle, resulting in defective inspection.

The contact pin 92 is inserted in a socket 91 fixed to the pin board 88. Therefore, the socket 91, the contact pin 92, and the guide hole 81 must have the same axis. Therefore, in order to smoothly slide the contact pin 92 having a small diameter, the guide hole 81 needs to be drilled with high dimensional accuracy so that the shaft centers coincide with each other.

The contact pin 92 is a socket 9
1 slides in the guide hole 81 and the inside of the guide hole 81 coaxially, and its tip 921 directly contacts the wiring circuit 75, so that it is easily damaged by the axial misalignment and contact. 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 contact pin 92 of the probe, the drilling accuracy of the guide hole 81 and the like. In view of such conventional problems, the present invention can cope with a reduction in the diameter of guide holes and contact pins and a reduction in the arrangement pitch associated with a higher density of a wiring circuit, and an inspection of a printed wiring board in which the contact pins are not easily damaged. It is intended to provide a jig.

[0014]

The present invention is an inspection jig for inspecting a wiring circuit in a printed wiring board by the presence or absence of electrical continuity, the inspection jig including a contact pin for contacting the wiring circuit and one end. A stopper terminal connected to the lead wire, a retractable conductive coil spring interposed between the contact pin and the stopper terminal and biased to push them outward, and the above members are stored. The housing includes a guide plate having a guide hole for mounting the contact pin so that the contact pin can be moved forward and backward, a rear board having a terminal hole for accommodating the stopper terminal, and the guide. A main board provided between the plate and the back board and having an insertion hole for accommodating the coil spring, and
An inspection jig for a printed wiring board is characterized in that a conductive intermediate member that comes into contact with the coil spring and the head of the contact pin is interposed between the coil spring and the head of the contact pin.

What is most noticeable in the present invention is that the above-mentioned conventional probe is divided into, as it were, three parts, and is composed of contact pins, stopper terminals, and coil springs. That is, the contact pin is brought into contact with the wiring circuit, the stopper terminal is connected to the lead wire, and a conductive coil spring is interposed between the contact pin and the stopper terminal. The coil spring is electrically conductive and can expand and contract, and is biased to push the contact pin and the stopper terminal outward.

Further, the housing for accommodating the above-mentioned members is composed of a guide plate for mounting the contact pins, a rear board for accommodating the stopper terminals, and a main board for accommodating the coil springs. Further, the guide plate is provided with a guide hole for mounting the contact pin so as to be able to move forward and backward, the rear board is provided with a terminal hole for accommodating the stopper terminal, and the main board is provided with an insertion hole for accommodating the coil spring.

Further, an electrically conductive intermediate member is provided between the coil spring and the head of the contact pin so as to contact them. In addition, it is preferable that the intermediate member includes a body portion inserted into the coil spring and a bottom portion that comes into plane contact with the head portion of the contact pin.

As a result, the bottom of the intermediate member comes into planar contact with the head of the contact pin. Therefore, electrical conduction between the intermediate member and the contact pin is reliable.
Further, the intermediate member is constructed so that its body is inserted into the inside of the coil spring, and the electrical connection with the coil spring is reliable. As a result, a stable electrical connection between the contact pin and the coil spring is ensured through the intermediate member.

[0019]

In the inspection jig of the present invention, the contact pin that advances and retreats in the guide hole of the guide plate and comes into contact with the wiring circuit, the stopper terminal that is the detection end of the electrical conduction state, and the interposition therebetween. It is configured to be divided into an installed conductive coil spring. The coil spring pushes the contact pin and the stopper terminal outward to electrically connect them. That is, the contact pin, the stopper terminal, and the coil spring are not mechanically integrated, unlike the probe in the conventional example.

The stopper terminal and the contact pin may be electrically connected via a coil spring. Therefore, there is no problem in the mutual positional relationship among the contact pin, the stopper terminal, and the coil spring even if there is a slight misalignment of the axial centers.

This is because the coil spring has flexibility and if the coil spring is urged to press the two even if there is some positional deviation of the axial center among the above three members. There is no chance that the three will be in a non-contact state,
This is because sufficient electrical continuity can be secured.

Further, by providing an intermediate member between the contact pin, which is a precision added component, and the coil spring, electrical conduction between the contact pin and the coil spring can be made more reliable. That is, the coil spring is formed in a spiral shape, and merely pressing the end of the coil spring against the contact pin leaves some anxiety about electrical conduction between the two.

However, by interposing the intermediate member between the two, it is possible to further stabilize the electrical connection between the contact pin and the coil spring. For example,
As described above, the structure in which the body of the intermediate member is inserted into the inside of the coil spring, and the bottom of the body is brought into planar contact with the contact pin, the electrical conduction between the contact pin and the coil spring becomes more reliable. .

As described above, in the inspection jig according to the present invention, the guide hole for mounting the contact pin, the terminal hole for accommodating the stopper terminal, and the insertion hole for accommodating the coil spring, as in the prior art, have their axes. It is not necessary to match the cores with high precision. Therefore, it is not necessary to position the guide hole, the terminal hole, and the insertion hole with high accuracy as in the conventional example.

Further, when the stopper terminal is housed in the terminal hole, even if there is some play between the two, the electrical continuity between the above three parties is not compromised. Therefore, the processing accuracy in terms of the shape of the terminal hole and the stopper terminal may be relatively rough. Further, as described above, high precision is not required for the alignment of the central position with the guide hole. Therefore, it is easy for these members to cope with higher density of printed wiring boards, smaller diameters and narrower pitches.

Similarly, regarding the relationship between the coil spring and the insertion hole, there is no problem even if there is some play between the two. Therefore, the coil spring and the insertion hole for accommodating the coil spring may have relatively rough machining accuracy in terms of shape. Further, since the coil spring accommodated in the insertion hole does not require an exterior member such as a socket in the conventional probe, the diameter is smaller than that of the conventional probe and the diameter of the insertion hole can be easily reduced.

Further, the intermediate member 50 is interposed between the coil spring 30 and the contact pin 10, and both members 3
It suffices to secure electrical continuity between 0 and 10 and is not a member that requires exceptionally high accuracy (Example, see FIG. 2). As described above, all of these members can easily cope with the high density of the printed wiring board, that is, the reduction of the diameter of the contact pins and the reduction of the pitch thereof.

The shaft center of the guide hole of the guide plate may be bored so as to be aligned with the wiring circuit of the printed wiring board, and the shaft center can be aligned with the insertion hole and the terminal hole as in the conventional case. It becomes unnecessary. Therefore, high-precision processing is not required, and it is easy to pierce and it is easy to cope with high density of the printed wiring board. In addition, since the guide hole only needs to allow smooth sliding of the contact pin, the diameter can be easily reduced, and the contact pin is prevented from rattling and damage to the contact pin is reduced.

Further, the contact pin directly contacts the wiring circuit and slides in the guide hole, but unlike the contact pin of the conventional probe, it does not rectilinearly advance and retract both in the guide hole and the socket of the probe. Therefore, it will not be damaged by shaft misalignment.

The contact pin is not integrated with the probe like the contact pin in the conventional probe, but is an independent member mounted in the guide hole. Therefore, if the guide plate is separated from the housing,
It is easy to remove the contact pin from the guide plate and replace it.

Therefore, replacement at the time of wear or reuse for another inspection jig is easy. Similarly, the coil spring can be easily removed from the insertion hole and replaced if the main board is separated from the housing. Therefore, the coil spring can be easily replaced and reused for other inspection jigs.

As described above, in the inspection jig of the present invention, the processing of each of the above members is significantly easier than in the prior art, and it is easy to deal with the high density of the printed wiring board. Further, the contact pin is less likely to be damaged, its durability is improved, and its replacement and reuse are easy. Similarly, the coil spring can be easily replaced and reused. Therefore, according to the present invention, it is possible to provide a jig for inspecting a printed wiring board, which can cope with a reduction in the diameter of the contact pins and the guide holes and a narrowing of the arrangement pitch as the density of the wiring circuit increases, and the contact pins are not easily damaged. can do.

[0033]

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 FIG. 1, the inspection jig 1 of this example has contact pins 10 for contacting a wiring circuit 71 of a printed wiring board 7.
And a stopper terminal 30 having one end connected to the lead wire 15, the contact pin 10 and the stopper terminal 3
An electrically conductive coil spring 20 which is expandable and contractible and is urged so as to press the both toward the outside.
And a housing 4 for accommodating the above-mentioned members 10, 20, 30.

The housing 4 has a guide plate 41 having a guide hole 45 in which the contact pin 10 is mounted so as to move forward and backward, a rear board 43 having a terminal hole 47 for accommodating the stopper terminal 30, and a rear board 43. The guide plate 4
1 and a rear board 43, and a main board 42 provided with an insertion hole 46 for accommodating the coil spring 20.

Further, between the coil spring 20 and the head portion 11 of the contact pin 10, a conductive intermediate member 50 that contacts the both 20, 11 is provided. As shown in FIG. 2, the intermediate member 50 includes a body portion 51 inserted into the coil spring 20 and a bottom portion 52 that comes into plane contact with the head portion 11 of the contact pin 10.

A detailed description will be given below in order. As shown in FIG. 1, the inspection jig 1 of this example accommodates a large number of contact pins 10, coil springs 20, and stopper terminals 30 in a housing 4. And contact pin 1
0 and the stopper terminal 30 are arranged on opposite sides of the housing 4, and the coil spring 20 is provided between them.
Are arranged.

The contact pin 10 is mounted in a guide hole 45 provided in a guide plate 41 constituting the housing 4 so as to be able to move back and forth. The pin tip 101 of the contact pin 10 is exposed outside the housing 4. Further, the contact pins 10 are arranged so that the pin tips 101 thereof face the inspection pads of the wiring circuit 71 of the printed wiring board 7 in a one-to-one manner.

As shown in FIG. 2, a head portion 11 having a slightly larger outer diameter is formed at the end portion of the contact pin 10 opposite to the pin tip 101. And the head 11 is
It is housed in a pin room 411 that communicates with the guide hole 45 and has a larger cross-sectional area than the guide hole 45.

On the other hand, the stopper terminal 30 is shown in FIGS.
As shown in FIG. 5, the rear board 43 is accommodated in the terminal hole 47 of the rear board 43, and the rear board 43 is provided on the opposite side of the housing 4 from the guide plate 41. The terminal holes 47 are formed in the same number in a one-to-one correspondence with the guide holes 45.

The lead wire 15 is connected to one end of the stopper terminal 30, and the other end of the lead wire 15 is connected to the inspector 18 as shown in FIG. The inspector 18 is a portion including an arithmetic circuit for determining the quality of the wiring circuit, a display unit 181, and the like.

As shown in FIG. 2, the terminal hole 47 comprises a terminal room 471 for accommodating the stopper terminal 30 main body and a wire hole 472 for inserting the lead wire 15.
The wire hole 472 is sized so that the lead wire 15 can be inserted therethrough, and has a diameter smaller than the diameter of the stopper terminal 30. As shown in FIGS. 3 and 4, the stopper terminal 30 includes a lead wire 15 in a tubular terminal tube 31.
The front end portion 151 of the above is inserted, and both are caulked and integrated as shown in FIG.

As shown in FIG. 1, the coil spring 20 is inserted into the insertion hole 46, and the insertion hole 46 is formed in the main board 42. The main board 42 is arranged in the middle of the back board 43 and the guide plate 41, and the three members 41 to 43 are integrated by a knock pin 891. Then, by removing the knock pin 891, the guide plate 41 and the main board 4 are removed.
2 and the back board 43 are formed so that they can be easily separated.

The coil spring 20 is biased to press the stopper terminal 30 and the contact pin 10 outward. Then, as shown in FIG. 2, the upper end ring 202 of the coil spring 20 is in contact with the lower surface 311 of the stopper terminal 30.

Further, as shown in FIG. 2, an intermediate member 50 is provided between the coil spring 20 and the contact pin 10.
Is installed. A cylindrical body 51 is formed on the upper portion of the intermediate member 50, and the body 51 is inserted into the coil spring 20. And the intermediate member 5
A bottom portion 52 having a diameter larger than that of the body portion 51 is formed in the lower portion of 0.

The bottom surface 521 of the bottom portion 52 is a flat surface and is in surface contact with the top surface 111 of the head 11 of the contact pin 10. The upper surface 522 of the bottom portion 52 is in contact with the lower end ring 201 of the coil spring 20.

Next, the function and effect will be described. Wiring circuit 7 of printed wiring board 7 having wiring circuits 71 on the upper and lower sides
When inspecting the quality of 1 by electrical conduction,
As shown in FIG. 5, the housing 4 is brought closer to each wiring circuit 71 from above and below, and the guide plate 41 faces the printed wiring board 7. At this time, before contact between them (upper part of Fig. 1)
Immediately after the contact (the lower part of FIG. 1), the contact pin 10 is in a state of protruding from the guide plate 41.

Then, the pin tip 10 of the contact pin 10
1 is pressed against the wiring circuit 71. Then, the contact pin 10 moves inward in the guide hole 45 while reducing the coil spring 20 against the biasing force of the coil spring 20. And the contact pin 10
The pin tip 101 presses the wiring circuit 71 by the urging force of the coil spring 20 to ensure electrical conduction between the two.

Similarly, electrical contact between the contact pin 10 and the intermediate member 50, between the intermediate member 50 and the coil spring 20, and between the coil spring 20 and the stopper terminal 30 is ensured by the biasing force of the coil spring 20. . Then, as shown in FIG.
The wiring circuit 71, the contact pin 10, the intermediate member 50, the coil spring 20, the stopper terminal 30 and the inspection device 18 are connected via the lead wire 15 connected to the inspector 18, and the quality of the wiring circuit 71 is determined. .

After the inspection, the housing 4 is moved away from the printed wiring board 7. And contact pin 1
0 is again projected from the guide plate 41 by the biasing force of the coil spring 20 and is restored to the original state (the upper part of FIG. 1).

As described above, in the inspection jig 1 of this example, the axis of the contact pin 10, the axis of the intermediate member 50, the center of the coil spring 20, and the stopper terminal 3 are used.
Even if there is some misalignment with the center of 0, it is 1
If 0, 50, 20, and 30 are in contact, there is no problem (see FIG. 5). Therefore, the guide hole 45 may be formed so as to match the wiring circuit 71 of the printed wiring board 7, and highly accurate alignment with the insertion hole 46 and the terminal hole 47 as in the conventional example is unnecessary.

Further, the guide hole 45 is formed by the contact pin 10
Since it is only necessary to allow smooth sliding, only a small diameter can be provided, and the contact pin does not rattle. Therefore, the high density of the printed wiring board 7 can be dealt with, and the wear of the contact pins 10 is significantly reduced as compared with the conventional example. Further, as described above, high accuracy is not required for the processing of the coil spring 20 and its insertion hole 46, the processing of the stopper terminal 30 and its terminal hole 47, and the processing of the intermediate member 50.

Further, as described above, the guide plate 41, the main board 42, and the rear board 43 can be easily separated. Therefore, it is easy to remove the contact pin 10, the intermediate member 50, the coil spring 20, and the stopper terminal 30 from the housing 4 and use them for another inspection jig 1.

That is, the guide plate 41, the main board 42,
The back board 43 needs to be separately manufactured in correspondence with the wiring circuit 71 of the printed wiring board 7, but the contact pin 1
0, the intermediate member 50, the coil spring 20, and the stopper terminal 30 can be diverted or replaced easily, and a large cost reduction can be achieved. Utilization of the contact pin 10, which is a particularly expensive precision component, can bring about a great cost reduction effect.

As described above, according to this example, the wiring circuit 7
1, the contact pin 10 and the guide hole 45 accompanying the higher density
It is possible to provide the inspection jig 1 for the printed wiring board 7 which is capable of coping with the reduction of the diameter and the arrangement pitch, and the contact pin 10 is not easily damaged.

[Brief description of drawings]

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

FIG. 2 is an enlarged cross-sectional view of a detection unit according to the embodiment.

FIG. 3 is a perspective view of a stopper terminal constituent member before being processed in the embodiment.

FIG. 4 is an enlarged perspective view of a stopper terminal according to the embodiment.

FIG. 5 is another enlarged cross-sectional view of the detection unit in the embodiment.

FIG. 6 is an overall explanatory view of an inspection jig in a conventional example.

FIG. 7 is an explanatory view around a probe of an inspection jig in a conventional example.

[Explanation of symbols]

 1. ． ． Inspection jig, 10. ． ． Contact pin, 11. ． ． Head, 15. ． ． Lead wire, 18. ． ． Inspection device, 20. ． ． Coil spring, 30. ． ． Stopper terminal, 4. ． ． Housing, 41. ． ． Guide plate, 42. ． ． Main board, 43. ． ． Back board, 45. ． ． Guide hole, 46. ． ． Insertion hole, 47. ． ． Terminal hole, 50. ． ． Intermediate member,

Claims (2)

[Claims] 1. A test jig for inspecting a wiring circuit on a printed wiring board according to the presence or absence of electrical continuity, the inspection jig connecting a contact pin for contacting the wiring circuit and one end with a lead wire. A stopper coil, a retractable conductive coil spring interposed between the contact pin and the stopper terminal and biased to press the contact pin and the stopper terminal outward, and a housing for accommodating the above-mentioned members. The housing includes a guide plate having a guide hole for mounting the contact pin so that the contact pin can be moved forward and backward, a rear board having a terminal hole for accommodating the stopper terminal, the guide plate and the rear board. And a main board having an insertion hole for accommodating the coil spring, and the coil spring and the contact pin. An inspection jig for a printed wiring board, characterized in that a conductive intermediate member that comes into contact with the two is interposed between the head and the head of the printed wiring board. 2. The inspection jig for a printed wiring board according to claim 1, wherein the intermediate member includes a body portion inserted into the inside of the coil spring and a bottom portion which comes into planar contact with the head portion of the contact pin. .