JPS58137773A - Fixture used for circuit substrate test system - Google Patents

Abstract

PURPOSE:To cope with a future pattern change, by providing preliminarily through holes, through which additional test probes should be inserted, in additional test probe positions other than test probe attaching positions. CONSTITUTION:Test probes 6-8 corresponding to all test points of a preliminarily determined number of kinds of PC board pattern are provided on a well 5 consisting of insulating materials such as a glass-epoxy resin. Terminals 6c-8c of test probes 6-8 are connected to a wiring post 14 through lead-in wires 10- 12. The well 5 is provided preliminarily with through holes 40 through which probes to be added in future are inserted. These through holes 40 can be provided in optional positions other than positions of probes 6-8, are ordinarily, they are provided in positions where parts may be added. Consequently, probes are attached to positions of through holes 40 corresponding to additional test points to cope with the addition of new parts.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fixtair system used in a circuit board test system for testing circuit boards, and in particular to a fixtair e system that can easily respond to design changes of circuit boards to be tested.
ζ related.

In recent years, on the production line for printed circuit boards (/' (, 'Boat)', it has become necessary to check whether each part of the 7'T' board, which is created by mounting IC's, LSIs, resistive elements, etc., satisfies the design specifications. Use a computer to check whether the circuit is connected correctly or not.1
The test system of this type has become popular1.In this type of test system, the PC board 2 to be tested is usually placed on a fixture l as shown in FIG.
CC port tAIIIJ test point (component bit/
, connection points, etc.), and conduct a characteristic test 1 between selected test points according to the test program, such as a resistance value test, a short circuit test, etc., to detect a failure location.

In such a fixture 1, pc ho 1”
The test points 2 and the test probe 3 must have a corresponding positional relationship, that is, the test glove 3 must be placed directly below the test point, and the positional relationship must be such that the test glove 3 comes into contact with the test point during inspection. Therefore, the arrangement configuration of the test probes differs depending on the pattern (component arrangement) of the PC board 2 to be tested. As shown in Figure 1, each test glove is implanted in a predetermined position in a well 5 made of insulating material. A so-called "universal size L-1-C" has been developed in which only the support plate for supporting the PC board is replaced and the fixture body is commonly used for different types of PCC board patterns. In this universal fixture, test gloves corresponding to all the test points of, for example, 10 types of PC board patterns are planted in the wells and are disposed approximately parallel to the top surface of the wells so as to be movable in the vertical direction. A support plate is provided to support the LO circuit board to be inspected. At the time of inspection,
The space formed by the well and the support grate becomes a vacuum, and the support grate is suctioned and displaced toward the well, allowing each test point on the back of the boat to be inspected to pass through the through holes provided in the support plate. Use the corresponding test gloves to make contact. However, even in such a universal fixture, the configuration of the test probes is for the type of PC' board pattern originally planned, so that one or more PC board patterns may be designed in the future. When changes occur, especially when new parts are added, it is necessary to install new test gloves that correspond to the additional test points1.In the past, the fixture was disassembled and the additional test points were added. A new 70mm through-hole is drilled in the well just below the hole, and an additional test glove is inserted and implanted into this through-hole.

However, the original test 10 already implanted in the well
- They are usually hundreds to thousands of trees and are very densely packed.
On the back side of the well, the lead-in wires for connecting each glove terminal to the computer side are tightly wired, making the work of planting such additional test gloves extremely troublesome and difficult. .

The present invention has been made in view of the above-mentioned problems, and includes providing in advance a through hole through which an additional test glove is passed through the additional test tube IJ-b position other than the test glove attachment position of the well, and bonding a sealing plate to the back surface of the well. The above-mentioned inconvenience is solved by the configuration characterized by this. Below, the second
Embodiments of the present invention will be described with reference to FIGS.

FIGS. 2A and 2B are cross-sectional views of a universal fixture V to which an embodiment of the present invention is applied. Figure 2-, t, s
In the VC, test 10-blocks corresponding to all test points of a predetermined number of types (for example, 10 types) of /'t' board patterns are formed in the HT well 5 from an insulating material such as glass Evokin resin. 6.7.8 (only three are shown for convenience of explanation) are planted. , the test probe 6.7.8 has socket parts ba, 7α, 8α inserted into the well 5 and fixed therein, and flow fiber bins 6b, 7b, 8b detachably inserted into the socket parts. , each globe terminal is supported by a compression spring (not shown) disposed at the inner bottom of the socket part.The terminals 6c, 7c, and Mc of the test globe 6.7.8 are
The winding is connected to the connected lead-in wire IL1. 11. 12 to a wiring post 14 of a contact panel 13 (FIG. 1). The wiring boss 14 is a Pt “boat” to be inspected.
The two test points are connected to a common bus of the computer via arrays, switches, and switching matrices (not shown). A support plate 15 is disposed inside the well 5 so as to be substantially parallel to the upper surface 16 of the well 5 and to be movable vertically and vertically. That is, the support grate 15 is supported substantially in parallel by a plurality of compression springs 17 disposed on the upper surface 16 of the well 5.
It is fitted so as to be movable in the vertical direction with respect to the inner circumferential surface 18 of. The support plate 15 is made of, for example, glass epoxy resin, and is provided with glove through holes at positions corresponding to each test glove. This ensures that when the support punch 16 is placed in the well 5, all test gloves 6.7, & are received in the corresponding through-holes 19, 20, 21 of the support plate 15, as shown in FIG. 2A. . An adapter plate 22 is disposed on the support grate 15, and the pre-test/JC board 2 is placed on this adapter plate 22. Therefore, in this universal type fixture, P
The C board 2 is supported by the support plate 15 via the adapter grate 22.

The adapter plate 22 is slightly smaller than the PC board 2, and around its periphery a sealing gasket 23 made of sponge is arranged. The material of the adapter plate 22 is
Any insulating material may be selected as long as it has strength enough to withstand the pressing force of an unused probe bottle during inspection and is suitable for working VC.

The adapter grate 22 has openings 24 and 25 corresponding to test points of a certain pre-test PC board pattern.
is provided, so that when the adapter plate 22 and the PC board to be inspected are placed and positioned, a second
As shown in Figure A, the probe bins 6α and 7G of the test glove 6.7 used for testing the PC board 2 are attachable.

Through the opening 24.25 of the rate 22 it faces the corresponding test point 26.27. On the other hand, this PC board 2
The glove bin 8b of the test 10-bu 8, which is not used for inspection, faces the bottom surface of the adapter plate 22.

The top surface of the adapter plate 22 and the top surface 16 of the well 5
A plurality of disc-shaped hard rubber stockings 28 and 29 are respectively arranged at appropriate positions. A rubber sealing gasket 30 is fixed to the upper peripheral edge of the support plate 15 . The lower side of the peripheral part 31 of the well 5 has an inner well space, that is, an upper surface 16 of the well 5 and a support plate 1.
A vacuum port 34 is provided which communicates with a space 32 formed by the bottom surface of the adapter plate 5 and a space 33 formed by the top surface of the adapter grate 22 and the back surface of the PC board 2 . A holding frame 35 is screwed onto the upper end of the peripheral portion 31 of the well 5 for holding the support plate 15 from above when it is released before and after an inspection as shown in FIGS. 2 and 4.

Further, in accordance with the present invention, the well 5 is provided with a through hole 40 in advance for passing a test probe to be added in the future (only one through hole 40 is shown in FIGS. 2A and 2B for convenience of explanation). This through hole 40 can be located at any location other than the initial attachment location of the test glove 6.7.8, but is usually located at a location where a component is likely to be added. Generally, the arrangement of components on a PC board is not random but standardized.

For example, in PC boards on which ICs, LSIs, etc. are mounted, bins and components are normally arranged in pitch units of 0.254 cm (0.1 inch). In other words, if we consider a lattice-like matrix with an interval of 0.254 crn vertically and horizontally on the PC board surface, every pin of every component will be located at a certain lattice point on this matrix.

Therefore, even if a new part is added, each bin of that part will be placed at one of the grid points. .

Taking this point into consideration, the locations of test points to be added in the future can be planned, and the through holes 40 may be drilled into the wells 5 at such test point locations. In particular, if through-holes 40 are provided at all grid points on the matrix (excluding the initial test probe mounting position), any (standardized) future parts will be added. Since there is always a through hole 40 corresponding to the test point, it is possible to completely correspond to the test point. The through hole 40 is normally drilled at the same time as the through hole at the original mounting location of the test glove 6.7.8, and the diameter of the through hole 40 is such that the test probe can be easily inserted by hand. It is preferable to select a diameter that minimizes the gap when testing (therefore, a diameter that is slightly larger than the diameter of the test probe).

A sealing plate 42 is bonded to the entire back surface 41 of the well 5 in relation to the through hole 40 .

The original test glove 6 as shown in Figure 2 ASB
．． The lower end of the through hole 40 protrudes from the sealing plate 42 into the external space 43, but the lower end of the through hole 40 is sealed by the sealing plate 42. The sealing plate 42 may be made of an insulating material that can withstand the pressure difference between the through hole 40 and the external space 43 when the well internal space is evacuated, is easy to work with, and has elasticity, and is preferably made of silicone. Rubber or selected.

That is, the sealing plate 42 made of silicone rubber is easily formed by applying semi-liquid silicone rubber to the back surface 41 of the well 5 and then drying it, and has sufficient strength and elasticity, and is suitable for testing gloves. can be easily inserted by hand, and when inserted, elastically adheres to the outer peripheral surface of the test glove (more specifically, the socket portion of the test glove), effectively sealing the space within the well.

To explain the operation of the z-universal type fixture configured as described above, the inspection i as shown in FIG.
When the well interior space 32, 33 is released after the well is opened, the well interior space 32, 33 is filled with air. At this time, the support plate 15 is urged upward by the compression spring 17 and is in a device constituted from above by the holding frame 35 (FIG. 2A), and the PC board 2
is supported on the gasket 23. At the time of inspection, the well internal spaces 32 and 33 are brought into a vacuum state through the vacuum port 34 by a vacuum pump 7 (not shown). As a result, the support grate 15 is attracted downward (that is, toward the upper surface 16 of the well 5) against the compression spring 17, and is seated on the upper surface of the stopper 29 (FIG. 2B). At the same time, P
The C-board 2 is also attracted downward (that is, toward the adapter plate 22) against the deformation elastic force of the gasket 23, and is seated on the upper surface of the stopper 28 (FIG. 2B). As a result, the test point on the back of the PC board) 26.2? Glove bin 6 of the corresponding used test gloves 6.7
b, in contact with 7b. The contact pressure between these test points and the probe bin can be adjusted by adjusting the thickness of the stopper 28, 29 or the elastic force of a compression spring (not shown) disposed inside the test glove socket that biases the probe bin upward. By doing so, the desired thickness is selected. On the other hand, at this time, the 7" lobe bin 8b of the non-use test 10-8 comes into contact with the back surface of the adapter plate 22 due to the downward displacement VC of the support plate 15 and the adapter plate 22, and is pressed further downward, as shown in FIG. As a result, the non-contact relationship between the unused test glove and the back surface of the PC' board is maintained reliably.

In addition, in this universal type fixture, the P to be inspected
The adapter slate is replaced according to the pattern of the C board. In other words, if the PC board under test has a different pattern, remove the current adapter plate and install another adapter plate that corresponds to the different pattern, i.e., open the opening corresponding to the test point of the other turn. The fixture body including the support plate is then commonly used as is.

When a design change occurs in the current PC board pattern and a new component is added, for example as shown by the dotted line 45 in FIG. 2 AXB, through holes corresponding to each bin (additional test point) of the component 45 40 through an additional test glove. In this case, the sealing plate 42 on the lower side of the through-hole 40 is pierced by the additional test glove, but the sealing plate 42 adheres tightly to the outer circumferential surface of the inserted additional test probe due to its elasticity and maintains the seal while performing additional tests. Hold the probe steady.

Although one embodiment of the present invention has been described above, the present invention is not limited to this embodiment, and various modifications and changes can be made within the scope of the technical idea. For example, the sealing plate 42 does not necessarily need to be bonded to the entire back surface 41 of the well 5, but may be bonded only to the necessary portion, that is, only to the portion where the test probe is implanted. Further, as shown by dotted lines in FIGS. 2A and 2B, there are also probe through holes 46 in the support plate 15 at positions corresponding to the through holes 40.
may be provided in advance; in that case, there is no need to remove the support grate 15 from the well 5, which is convenient;
Furthermore, it is convenient if the adapter plate is made of a transparent material because the positions corresponding to the through holes, that is, the positions of the additional openings can be easily seen from above.

The present invention is also applicable to another universal type fixture as shown in FIG. 7.1 of this figure 3
Custia does not have an attarpter plate,
Instead, the upper surface 7 root 50 corresponding to the support plate directly places the PC board 2 to be tested. Therefore, in this fixture, the top plate 50 is replaced depending on the type of pattern on the PC board 2 before being tested. A recessed hole 51 is provided in the top plate 50 to prevent the probe bin 8α of the test probe 8 that is not used for testing the PC board 2 from coming into contact with the back surface of the PC board 2. In such a fixture, a through hole 4o for passing (inserting) an additional test 7° rope is provided at an additional test probe mounting position other than the initial test glove 6.7.8 mounting position, and a through hole 4o is provided for passing (inserting) the additional test 7° rope. The sealing plate 42 may be adhered to the holder, and in that case, the same effect as described above can be obtained. In addition, Figure 3 shows the operating state at the time of inspection.
In the figure, parts corresponding to those in FIGS. 2A and 2B are given the same reference numerals. Furthermore, the present invention is of course applicable to a dedicated type fixture.

As described above, according to the present invention, even if there is a design change in the PC board before being tested, especially if the component strength is zero, a fixation that can be easily adapted to the design change can be obtained.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a conventional 71x steer used in a printed circuit board test system, and FIG.
FIG. B is a sectional view showing one embodiment in which the present invention is applied to a universal type fixture, and FIG. 3 is a sectional view showing another embodiment in which the present invention is applied to another universal type fixture. 2... Printed circuit board (PC board), 5... Vacuum well, 3.6, 7.8... Test probe, 15
...Support grating, 22...Adapter plate, 3
2.33...Well interior space, 40...Through hole, 50
...Top plate L1 figure Tail 3 figure Hair 2 figure A Curtain 2 figure B

Claims (2)

[Claims] (1) comprising all test wells of a predetermined number of types of circuit boards, and a support grate disposed substantially parallel to the upper surface of the well so as to be movable in the vertical direction and supporting the circuit board to be inspected; During inspection, the space formed by the well and the support grate becomes a vacuum, and the support bullet is exposed to F.
A circuit board test in which each test point on the back side of the circuit board to be inspected is brought into contact with the corresponding test probe through the ml hole provided in the support grate, by suctioning and displacing the circuit board to be tested. In Fixture used in the system. 1! A fixture characterized in that a through hole for passing an additional test glove is provided in advance at an additional test glove position other than the test glove attachment position of the II Me well, and a sealing plate is adhered to the back surface of the well. (2) 71 Custia according to Clause 1 of the Claims, characterized in that the QU8 sealing material is made of silicone rubber.