EP0543808A1

EP0543808A1 - Spring contact field component for wiring/printed circuit board testing device

Info

Publication number: EP0543808A1
Application number: EP19900912005
Authority: EP
Inventors: Paul Mang; Hubert Driller
Original assignee: Mania GmbH and Co
Current assignee: Mania GmbH and Co
Priority date: 1990-08-13
Filing date: 1990-08-13
Publication date: 1993-06-02
Also published as: WO1992003741A1; DE9017923U1

Abstract

L'invention a pour objet un banc de contacts à ressorts pour un appareil de contrôle de circuits imprimés qui présente des orifices (7) mutuellement espacés qui traversent cet appareil depuis une face frontale jusqu'à la face frontale opposée, des ressorts de pression (9) pouvant être insérés dans les orifices (7), ressorts qui établissent des liaisons électriques entre des fiches de contrôle (2), dont l'une des extrémités est disposée contre l'une des extrémités du ressort, et des contacts (3) d'un réseau qui sont placés contre les autres extrémités des ressorts de pression (9). Pour simplifier la fabrication d'un tel banc, il est proposé que le banc (1) soit composé de plusieurs segments (6) superposés et que dans les orifices (7), placés dans le même alignement les uns par rapport aux autres, des segments (6) on insère de petits tubes (8) qui reçoivent les ressorts de pression (9). A cet effet, les segments (6) peuvent être fabriqués en céramique ou en matière plastique et les petits tubes constitués de métal, de céramique ou de matière plastique.The subject of the invention is a spring contact bench for a printed circuit control device which has mutually spaced orifices (7) which pass through this device from a front face to the opposite front face, pressure springs ( 9) can be inserted into the holes (7), springs which establish electrical connections between control plugs (2), one end of which is disposed against one of the ends of the spring, and contacts (3) of a network which are placed against the other ends of the pressure springs (9). To simplify the manufacture of such a bench, it is proposed that the bench (1) be composed of several superimposed segments (6) and that in the orifices (7), placed in the same alignment with each other, segments (6) are inserted small tubes (8) which receive the pressure springs (9). For this purpose, the segments (6) can be made of ceramic or plastic and the small tubes made of metal, ceramic or plastic.

Description

Spring contact field body for a wiring carrier / circuit board tester

The invention relates to a spring contact field body for a wiring carrier / circuit board tester according to the preamble of patent claim 1.

From the European patent application 87 109 884.4-2202 a printed circuit board test device emerges with a plurality of contact points arranged in the contact field level of the device, which are connected to an electronic control and measuring device and which are connected in the longitudinal direction to the contact points by rigid test pins testing wiring carriers or printed circuit boards are connectable. The contact points mentioned are designed as electrically conductive compression springs which are arranged in bores of a spring contact field body made of an electrically insulating material. The rigid test pins are supported on one end of the springs held in the bores of the spring contact field body. The other ends of the springs held in the bores of the spring contact field body are supported on contact pins of contact field plugs.

The known spring contact field body is produced, for example, as a fully plastic body by an injection molding process in an injection mold. One for making - -

of such a spring contact field body to be used injection mold is relatively complicated, since it must have inserts to form the bores mentioned. Since the holes have a diameter of about 0.8 mm, and since the distance from hole to hole is 1.27 mm according to the pitch of the contact points, it can be seen that the arrangement of the inserts in the injection mold must be extremely precise. During or before the spraying operation, these inserts must not bend in the injection mold.

The object of the present invention is therefore to provide a spring contact field body which can be produced comparatively easily without the use of a complicated injection mold.

This object is achieved by a spring contact field body, which is characterized by the features specified in the characterizing part of patent claim 1.

The main advantage of the invention is that the manufacture of the spring contact field body is considerably simplified due to its special structure. This can be attributed to the subdivision of the spring contact field body into individual segments which are stacked vertically one above the other. Because these segments each only have a small thickness of, for example, about 3 mm, they can be produced in injection molds with relatively short inserts, and there is no risk of these inserts bending due to their short length of, for example, 3 mm.

The present spring contact field bodies can be assembled relatively simply in that the individual segments are arranged vertically one above the other and aligned with one another, and in the mutually aligned bores of these segments thin tubes, preferably made of metal, with a very thin wall thickness, preferably in a range of 50 µm can be inserted. The tubes advantageously ensure that smooth transitions are created between the mutually aligned bores of adjacent segments. At the same time, the tubes mentioned cause the segments to be held together in the form of a compact block. The smooth transitions between the bores of adjacent segments mentioned prevent damage to the springs inserted into the bores. However, it is also possible to produce these tubes from ceramic or plastic.

Further advantageous embodiments of the invention emerge from the subclaims. - -

The invention and its configurations are explained in more detail below in connection with the figures. It shows:

1 shows an assembled spring contact field body;

2 shows an exploded view of the individual parts of an existing spring contact field body;

3 shows a further development of the invention; and

4a, 4b and 4c different alternatives of the design of the compression springs in the spring contact field body.

The present spring contact field body is designated by 1 in FIG. 1. It establishes a connection between test pins 2 and the contact pins 3 of a contact field which is preferably formed by contact field plugs 4. Each contact field connector 4 sits at the upper end of a so-called driver plate 5 which carries the electronic components which contribute to the electronic testing of the 4x32 = 128 contact points of a contact field connector 4. At the lower end of each driver plate 5 there is a contact plug, not shown, which connects each of the up to 2000 driver plates 5 to an electronic control and measuring device, also not shown, which is located in the lower part of the test Device is arranged. Since neither the contact field plugs nor the driver plates are of essential importance for the invention, these are not explained in more detail. As can be seen, the spring contact field body 1 consists of a plurality of disk-shaped segments 6 arranged vertically one above the other. In each segment 6 there are bores 7 corresponding to the grid of the contact pins 3, each hole having a diameter of approximately 0.8 mm and the distance from bore to bore corresponding to the pitch of the contact pins 3 is 1.27 mm. The size of the individual segments 6 can be chosen as desired, so that a desired number of contact pins 3 is detected. For example, the dimensions of a segment are 20x20x3mm. Such a segment has 256 bores 7.

2, the spring contact field body 1 is formed by stacking the segments 6 provided with the bores 7, the segments 6 and therefore also the bores 7 being aligned with one another during the stacking operations. For the sake of simplicity, many holes 7 are represented by dots. Tubes 8 are inserted into the mutually aligned bores 7. The tubes 8 ensure that there is a smooth transition between the mutually aligned bores 7 of adjacent segments 6. The tubes 8 - o -

consist preferably of metal, ceramic or plastic. Their wall thickness is preferably around 50 μm, while their outside diameter is around 0.8 mm.

A compression spring 9 is inserted into each tube 8, which in the manner already mentioned establishes contact between the end of a test pin 2 facing it and an associated contact pin 3.

In order to further facilitate the assembly of the spring contact field bodies, it is conceivable to preassemble the springs 9 in the tube 8 according to FIG. 3, so that these two elements can be inserted as a unit into the bores 7 of the segments 6 stacked one above the other. The springs 9 are preferably retained in the tubes 8 by providing them with constrictions or indentations 10 at their end regions, which form contact surfaces for the slightly compressed springs 9 located between them.

It should be noted that the lengths of the tubes 8 are matched to the lengths of the springs 9. The number of segments 6 to be stacked is determined by the lengths of the tubes 8. Preferably, the number of segments 6 and their thicknesses are chosen so that the ends of the tubes 8 in the planes of the -? -

Outer surfaces of the upper segment 6 and the lowest segment 6 lie.

According to Fig. 4a, the spring 4 at both end regions 11, 12, i.e. thus outwards from the resilient region 13, which has turns spaced apart, can be wound with turns lying against one another in the longitudinal direction, which taper in diameter to form an inner cone in the winding direction of the spring and then widen again. In this way, an inner cone 14 for receiving the tips of the test pins 2 and the contact pins 3 is formed on both ends of these springs 6. These springs 4, which are wound from spring steel, can preferably be coated by galvanic deposition with a suitable contact material, the windings lying against one another being able to "grow together" at the front ends.

In order to achieve the fastening of the springs 9 in the tubes 8 explained in connection with FIG. 3, these can have the mentioned constrictions or impressions 10 in the area of the inner cones 14.

According to FIG. 4b, the spring can have an inner cone 1.4 at its upper end region 11, as has already been explained in connection with FIG. 4a. The opposite end region 12 can be pin-like - -

Have tapering approach 15, the individual windings in turn abut each other. This pin-like extension 15 projects into, for example, a conical or cup-shaped depression which is located in the contact field connector 4 or in a contact element 3. 4c, the upper end region 11 of the spring 9 can have the inner cone 14 already explained. The lower end region 12 is provided with a contact tongue part 16 which extends directly to an associated contact point on the surface of a driver plate 5. This means that the contact field plug 4 only has to be provided with correspondingly positioned thin circumferential bores 17 through which these contact tongues 16 are introduced when the contact field is being set up.

It is pointed out that in the embodiments 4b and 4c the constrictions or impressions 10 already explained in connection with FIG. 3 can also be provided on the tubes 8.

Claims

Patent claims

1. Spring contact field body for a wiring support / printed circuit board testing device which has spaced-apart bores (7) which penetrate it from one end face to the opposite end face, compression springs (9) being insertable into the bores (7) that produce electrical connections between test pins (2), one end of which abuts their one end region, and contact elements (3) of a grid field, which abut the other end regions of the compression springs (9), characterized in that the body (1) is composed of a plurality of segments (6) stacked one on top of the other and that tubes (8) which hold the compression springs (9) are inserted into the bores (7) of the segments (6) which are aligned with one another.

2. Body according to claim 1, characterized gekennzeich¬ net that the segments (6) are made of ceramic or plastic.

3. Body according to claim 1 or 2, characterized gekenn¬ characterized in that the tubes are made of metal, ceramic or plastic. -40 -

4. Body according to one of claims 1 to 3, characterized in that the end regions of the tubes (8) are provided with constrictions (10) which form contact points for the ends of the compression spring (9) located between them.

5. Body according to claim 4, characterized gekennzeich¬ net that the compression springs (9) on at least one Endbe¬ area (11 or 12) due to a step-shaped and / - or continuous reduction of the spring coil diameter with simultaneous abutment of the Windun¬ gene have a pin or cone-like shape for direct contact with an inner cone or other surface and that the constriction (10) forms a system for the reduced spring coil diameter.

6. Body according to claim 4, characterized gekennzeich¬ net that the compression springs (9) on at least one end (11 or 12) due to a reduction and subsequent enlargement of the spring coil diameter with simultaneous application of the windings, the shape of an inner cone for direct reception one end of a test pin (2) or a contact element (3) and that the constriction (10) engages in the area formed by the reduction and the enlargement that is included.