JPS6161560B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an insert tester jig used when inspecting a printed circuit board package under test with an insert tester.

Conventionally, parts mounting of printed circuit board package was reversed.
The usual method is to visually check assembly defects such as incorrect or forgotten attachments or defects in mounted parts by an operator, and then send them to the subsequent function testing process. However, in recent years, with the increase in the number of parts mounted on a single printed circuit board, it is not always possible to conduct an efficient visual check, and furthermore, the above-mentioned component defects cannot be detected by visual inspection, so it is necessary to check them in the next process. This is usually discovered, and in this case there is an inconvenience that the visual check process is wasted. For this reason, in-circuit testers have come to be used to automatically check for such defects. This in-circuit tester automatically checks the mounted parts one after another when a package with parts already mounted and soldered is mounted on the tester jig, and displays GO/NG results and details of assembly defects and component defects. This is to report to the worker. In other words, with an in-circuit tester, a large number of spring probes are pressed simultaneously against all nodes (electrical connection points between components) of the package under test, and the test is performed by applying the tester's measurement circuit to each component to be measured. The process is carried out serially, one part at a time. At this time, since the package under test has already been soldered, in order to electrically isolate the component to be measured from surrounding components, apply a ground signal, etc. to nodes other than the measurement terminals. It is common for such measures to be taken.

FIG. 1 shows a conventional insert tester jig used for this purpose. That is, in Fig. 1, the left and right pillars 1
A bed plate 2 is fixed to the top of the board 2, and spring probes 5 are provided on the bed board 2 at positions corresponding to each node of a package 4 under test in which an electronic component 3 is installed. This spring probe 5 is always urged upward by a spring 6, and is electrically connected to a connector (not shown) via wiring 7, and an insert circuit tester (not shown) is connected to this connector. In addition, a positioning guide 8 is provided on the top surface of the bed board 2.
is provided, and the package under test 4 is supported by this positioning guide 8.

Guide rods 9 are erected at both ends of the upper surface of the bed plate 2, and a presser plate 10 is slidably attached to the guide rods 9. This presser plate 10 has
A presser bar 11 is attached corresponding to a position on the component surface of the package under test 4 where there is no component 3, and a presser plate 10
By applying air pressure or the like in the direction of arrow A in FIG.
is pressed against the spring probe 5 side.

In such a configuration, a predetermined voltage is applied to each node of the package under test 4 from an unillustrated insert circuit tester via the connector, wiring 7 and spring probe 5 to perform measurement.

However, in such a conventional method, the bed plate 2 and the holding plate 10 of the jig must be replaced every time the type of package 4 to be tested changes. In other words, the pattern of each package 4 under test is not the same, and when the type changes, the size and quantity of parts change, so the position of the node also differs depending on the type of package, and the non-mounted position of the part 3 also changes. This is because they are different. For this reason, when measuring several types of packages 4 under test with an in-circuit tester, the cost of the jig becomes high, and especially when performing high-mix, low-volume production where there are many types of packages and a small number of boards of the same type are produced, a huge amount of jigs are required. This is costly and, as a result, it is not possible to easily introduce an in-circuit tester.

SUMMARY OF THE INVENTION An object of the present invention is to provide a jig for an in-circuit tester that can cope with changes in the pattern of a package under test without making slight changes to parts, especially without changing expensive probes.

In the present invention, a large number of slide probes are provided on a bed plate, and these slide probes are made to protrude toward the test point side of a package under test by a post installed on a post stand, and the posts are arranged to be connected to the pattern of the package under test. In addition, a presser bar is installed on the presser plate so that the mounting position can be changed, and the presser bar presses the non-mounted position of the component on the component surface of the package under test to attach each test point and post. This is intended to achieve the above object by applying a contact force with the protruded slide probe.

Embodiments of the present invention will be described below based on the drawings.

Generally, the printed circuit board package 21 under test is
As shown in FIG. 2, the mounting holes (i.e., node positions) 23 of the mounting component 22 are arranged at regular intervals,
For example, they are provided so as to always match grid intersection points such as 2.54 mm or 2.50 mm. The present invention is applied to an in-circuit tester for the package under test 21 which is designed and manufactured under the condition that the spacing pitch is constant.

An embodiment of the present invention is shown in FIGS. 3-5. In FIG. 3, a support stand 25 is provided on the base 24, and a thick post stand reinforcing plate 27 is provided at the center of the support stand 25 via a locking step 26.
is removably attached with bolts 28 and nuts 29. Pillars 30 are erected on the upper surfaces of both sides of the support stand 25, and a bed plate 31 is fixed between the upper ends of the pillars 30. Slide probes 32 are slidably installed through the bed plate 31 in a grid pattern at intervals (see FIG. 4). This slide probe 32, as shown in FIG. ,3
A spring 35, such as a compression coil spring, is interposed between the two contacts 33 and 34 and biases the contacts 33 and 34 in the direction of protruding apart from each other.The entire slide probe 32 normally hangs downward from the bed plate 31 due to its own weight. The top plate 31 is connected to the top end of the top contact 34.
It is locked and prevented from coming off.

A frame 36 is provided on the upper surface of the bed plate 31 at a position outside the range where the slide probe 32 is provided, and a stepped opening 37 is provided in the center of the frame 36. The package under test 2 is connected to the portion 37 via a support spring 38.
1 is placed and supported.

Furthermore, guide rods 39 are erected at the four corners of the upper surface of the bed board 31, a support plate 40 is hung between the upper ends of the guide rods 39, and a stopper 41 is fixed to each middle of the guide rods 39. A press plate 42 is slidably supported on the guide rod 39 between the stopper 41 and the support plate 40. As shown in FIG. 5, this holding plate 42 has a plurality of strips formed at predetermined intervals and having a length approximately corresponding to the width of the package under test 21, that is, the width in the direction perpendicular to the plane of the paper in FIG. A square groove 43 is provided. The upper end square portion 45 of the presser bar 44 is slidably engaged with these grooves 43.
A threaded portion 46 is formed further above the square portion 45 of the presser bar 44.
5 is inserted into the groove 43, the presser bar 44 is projected upwardly from the presser plate 42, and the nut 47 is screwed into the protruding threaded portion 46 and tightened.
can be fixed at any position in the groove 43. At this time, the positioning plate 48 is used to position the presser bar 44 because the fixing position of the presser bar 44 needs to be a position on the component surface of the package under test 21 where the component 22 is not mounted. This positioning plate 48 is provided for each predetermined pattern of the package under test 21, and is provided with a plurality of presser bar positioning holes 49 at positions corresponding to non-component mounting portions of each pattern. As a result, if the presser bar 44 is fixed to the presser plate 42 with the lower end of the presser rod 44 inserted into the hole 49 of the positioning plate 48, the package under test 21 can be fixed for each pattern.
Can be positioned in areas where parts are not mounted. In addition, as the positioning plate 48, a bare board of the package 21 to be tested is used, and the package 21 is
It can be easily manufactured by drilling a hole at the appropriate presser bar position.

A fluid pressure cylinder 50 as a pressurizing drive source is attached to the center of the support plate 40, and the tip of a piston rod 51 of this cylinder 50 is fixed to the upper surface of the presser plate 42, and as the piston rod 51 moves back and forth. The presser plate 42 is configured to move up and down using the guide rod 39 as a guide.

A post stand 53 is fixed onto the post reinforcing plate 27 via a mounting stand 52. This post stand 53 is provided with a post 54 at a predetermined position to push up the slide probe 32 toward the package under test 21 against its own weight. This post 54 is connected to a connector 56 provided on the lower surface of the post stand 53 by a wiring 55, and a tester side connector 57 is connected to this connector 56. An in-circuit tester (not shown) is connected to this tester-side connector 57 via a cable 58 so that a predetermined signal can be transmitted to the post 54. Here, the post stand 53 is manufactured using, for example, the same bare substrate as that used for the package under test 21 or the package under test 21 with holes drilled in a lattice shape with the same pitches as the mounting pitches of the slide probes 32. It can be manufactured at low cost by using a larger universal board.

In such a configuration, the package under test 2
In order to perform the test No. 1, a post stand 53 with a post 54 planted at a position corresponding to the component mounting position of the package under test 21, that is, a node (point under test).
The upper end of the slide probe 32 at a predetermined position is made to protrude above the bed board 31 using a slider. on the other hand,
The positioning plate 48 is set so that the presser bar 44 is located at the position where the component 22 of the package 21 under test is not mounted.
The position of the presser bar 44 with respect to the presser plate 42 is set using The large protruding slide probe 32 is brought into contact with each node of the package 21 under test. In this state, the cable 58, tester side connector 57, connector 56,
Wiring 55, post 54 and slide probe 3
A test is performed by sequentially applying a signal to each node via 2.

Furthermore, since the unused slide probe 32 does not hit the package under test 21, the force exerted by the fluid pressure cylinder 50 to push up the package under test 21 is approximately the same as in the past, so the pressing force is also approximately the same as in the past. is sufficient.

When testing a different type of package under test, use a post stand 53 with posts 54 corresponding to the nodes of the package under test 21 and wiring 55 to the connector 56, and use the presser rod 44. If you change the position of , you can test in the same way as above.

According to this embodiment as described above, tests can be performed on different types of test packages 21 by simply replacing the post stand 53 with the posts 54 planted at predetermined positions and changing the position of the presser rod 44. can reduce jig costs. Further, since the post base 53 is provided with the post reinforcing plate 27, it is possible to prevent the post base 53 from deflecting, and it is possible to effectively prevent the slide probe 32 from having a weak contact force due to the deflection of the post base 53. Furthermore, since the package under test 21 is pressed by the presser bar 44, the package under test 21
When replacing the stepped opening 37 of the frame 36
Since it is only necessary to place the support spring 38 on the support spring 38 provided on the support spring 38, the replacement work is simple.
Moreover, since the slide probe 32 is equipped with a spring 35, the upper contact 34 can be brought into contact with each node, and the lower contact 33 can be brought into contact with each post 54, and at the same time, it is possible to prevent excessive force from being applied. . Furthermore, the number of wires from the slide probe 32 connected to the tester is the same as the number of nodes on the package under test 21, that is, the required number of slide probes, as in the conventional method. Since there is no need to add a circuit for electrically selecting an arbitrary slide probe 32 for each test element, and there is no need to change the tester body, a conventional tester can be used as is. In addition, the presser plate 42 is provided with a groove 43, and the position of the presser bar 44 can be changed in this groove 43, so the pressing position of the presser bar 44 can be easily changed for different types of packages 21 under test. It can correspond to the package 21 under test. Furthermore, if the positioning plate 48 is used to position the presser bar 44, the positioning can be performed even more easily.

In carrying out this embodiment, the pressurizing drive source is not limited to the fluid pressure cylinder 50, but other configurations such as a combination of a motor and a rack and pinion may be used. Furthermore, if a flexible member such as a rubber pad is attached to the tip of the presser bar 44 on the side that comes into contact with the package under test 21, damage to the package under test 21 can be effectively prevented.

6A, B, and C show the detailed structure of one embodiment of the slide probe 32 in the above embodiment, where A is an enlarged sectional view showing the internal structure, and B is a free section that is not pushed up by the post 54. falling state,
C is a diagram showing a state of being pushed up by the post 54. In FIG. 6A, the slide probe 32 has a lower end that can contact the post 54 and has an acute angle and an outer diameter that is hollow at the upper end.
Insert the lower contact 33 of d ₁ and the stepped retaining part 59 at the lower end into the upper hollow part of the lower contact 33 to prevent the lower end from coming out, and to attach the upper end to the package 21 under test.
An uneven surface 60 that can be contacted with the test point (node) of
The upper contact 34 has an outer diameter d ₂ , and the upper contact 34 has an outer diameter d 2 .
It is interposed between the lower surface of the retaining portion 59 of No. 4 and the bottom surface of the hollow part of the lower contact 33, and is inserted between the lower contact 33 and the post 54 and the upper contact 34 and the node of the package under test 21. Spring 3 consisting of a compression coil spring or the like, which ensures contact at the time of contact.
5, and an inner diameter d 3 that is larger than the outer diameter d ₁ of the lower contact 33 and smaller than the outer diameter d ₂ of the upper part of the upper contact ₃₄ (d ₁ < d ₃ < d ₂ and d ₃ - d ₁ = 200 600 .mu.m), and a cylindrical body 61 which slidably houses the lower contact 33, prevents the upper part of the upper contact 34 from coming off, and is further attached to the bed plate 31.

In FIG. 6B, the post 54 is attached to the post plate 53.
If there is no contactor 33, the lower contactor 33 slides inside the cylinder 61 due to its own weight and is in the lower position, and the upper part of the upper contactor 34 is locked to the upper edge of the cylinder 61 to prevent it from coming off. ing. At this time, the lower end of the lower contactor 34 does not come into contact with the post plate 53 even if the lower contactor 34 is in a hanging state.

In FIG. 6C, the post 54 is attached to the post plate 53.
When the lower contact 33 is placed upright, the lower end of the lower contact 33 comes into contact with the upper surface of the post 54, preventing it from falling due to its own weight, and the upper contact 34 is attached to the bed plate 3.
1, and the uneven surface 60 at the upper end comes into contact with a node of the package under test 21 (not shown). At this time, spring 35
Post 5 to obtain appropriate contact pressure.
4, the lengths of the upper and lower contacts 34, 33, the free length of the spring 35, the spring constant, etc. are determined.

According to this embodiment, since the lower contactor 33 is slidably guided by the cylindrical body 61,
The lower contactor 33 can be guided smoothly regardless of the thickness of the bed plate 31 and the surface roughness of the cylinder mounting hole.
Further, since the spring 35 is interposed between the upper and lower contacts 34 and 33, contact with the node and post 54 can be made with appropriate pressure. Since the lower end of the lower contact 33 is provided with an acute angle, electrical contact between the upper and lower contacts 34, 33 and the node and post 54 can be ensured.

As described above, according to the present invention, it is possible to provide a universal jig that can be commonly used for a large number of packages under test having different patterns, and the cost of manufacturing the jig can be significantly reduced. Therefore, it has become economically easy to introduce an in-circuit tester even in cases where it has been difficult to use an in-circuit tester to test packages that are produced in a wide variety of small quantities, and visual checks after printed circuit board assembly have become easier. It can be automated and improve the removal rate of defective products.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a conventional jig for an in-circuit tester, Fig. 2 is a plan view of a printed circuit board package to be tested used in the present invention, and Fig. 3 is a jig for an in-circuit test according to the present invention. FIG. 4 is a perspective view of the bed plate in the embodiment shown in FIG. 3, FIG. 5 is a partially exploded perspective view of the presser plate and presser bar in FIG. 3, and FIG. 6 is a partially sectional front view showing the embodiment. A
-C show one embodiment of the slide probe used in the insert tester jig of the present invention, where A is an enlarged cross-sectional view, B is a cross-sectional view in a state where it does not contact a post, and C is a cross-sectional view in a state where it does not contact a post. FIG. 21...Test (printed circuit board) package,
22...Parts, 31...Bed plate, 32...Slide probe, 33...Lower contact, 34...Upper contact, 35...Spring, 42...Press plate, 43
... Groove, 44 ... Presser bar, 48 ... Positioning plate,
53... Post plate, 54... Post, 59... Retaining portion, 60... Uneven surface, 61... Cylindrical body.

Claims (1)

[Scope of Claims] 1. The package is slidably inserted into a plurality of through holes arranged in a bed board that supports the package under test after parts have been assembled, and is normally in a hanging state due to its own weight, and in this hanging state, the bed board A large number of slide probes are provided that are prevented from coming off downward from the base plate, and the upper part of the slide probe at a position that is in contact with the test point of the component is projected above the bed plate. A jig for an in-circuit tester, characterized by having a post electrically connected to a point to be tested. 2. In claim 1, the slide probe is formed of a lower contact, an upper contact, and a spring, and the lower contact is slidably inserted into a cylinder attached to the bed plate. the lower end of the upper contact is formed to be able to contact the post, the lower end of the upper contact is telescopically connected to the upper end of the lower contact, and the entire upper contact is expandable and contractible;
and a diameter larger than the inner diameter of the cylindrical body of the bed plate, and the spring is inserted between the lower contactor and the upper contactor to bias both contacts in a direction away from each other so that the entire body expands. A jig for an insert circuit tester, characterized in that the jig is formed in such a manner that the