GB2107526A

GB2107526A - Thermal interface for electrical equipment

Info

Publication number: GB2107526A
Application number: GB08130815A
Authority: GB
Inventors: Eugeniusz Czeslaw Ja Jezierski; Geoffrey Paul Moore; Melvyn Sullivan
Original assignee: Standard Telephone and Cables PLC
Current assignee: STC PLC
Priority date: 1981-10-13
Filing date: 1981-10-13
Publication date: 1983-04-27
Also published as: DE3237094A1

Abstract

In an electrical equipment practice the need arises to mount substrate devices, such as relatively large hybrid integrated circuit units. This is achieved by mounting each such substrate (2) to a heat-sink (1) or a metal wall via a thermally- conductive washer (3) of a relatively soft material. The substrates are held in place by fasteners (4) at their corners. In an alternative the power distributor uses a multi-layer plate mounted on the heat-sink with holes via which the substrates, each with its washer, are mounted to the heat sink. <IMAGE>

Description

SPECIFICATION Electrical equipment practice This invention relates to an electronic equipment assembly, or so-called equipment practice, especially for use in telecommunications and industrial installations.

In such an installation it is often necessary to mount so-called high-technology substrates or advanced components or units to a heat sink. This invention has as its object a convenient arrangement for mounting such devices.

According to the invention there is provided an electrical equipment mounting arrangement, in which circuit unit substrates are each mounted to a flat surface of a heat sink or heat conductive metal wall by a flat washer of a thermally conductive soft material.

Embodiments of the invention will now be described with reference to the accompanying drawing, in which Fig. 1 shows how the invention is applied to the mounting of substrates, while Fig. 2 is another variant of how a a substrate may be mounted.

In Fig. 1 we have a heat-sink arrangement 1 having a number of fins, shown gapped to indicate that they can have varying lengths.

The heat-sink, which could also be a flat metal wall, is used to support a number of substrates such as 2, each of which is spaced from a flat face of the heat-sink 1 by a soft thermally conductive interface washer 3. This washer provides a good thermal contact between the substrate and the heat-sink, but without the inconveniences of the pastes or greases usually used and which are inherently thermal isolators. Removal of a substrate such as 2 for maintenance is easily achieved by releasing four quarter-turn fastener such as 4, two of which are on one of a number of compliant retaining strips 5 while the others are on a connector strip such as 5.

Each double column of substrates is separated from the next by a wall such as 6 which is a vertical line printed circuit board or cable support.

In the arrangement shown in Fig. 2, a multi-layer plane 10 is used for power distribution, and the substrates such as 11 are located on the heat-sink 12 via holes in the plane 10. A clamp/power connector 13 with compliant contacts provides power connections to the substrate and securely retains it against the heat-sink wall via a thermal interface washer 14.

Signal connections to the substrate are made via a flexible film wiring overlay 15 permanently connected to a matrix of pins or surface sites on the substrate. This overlay is terminated at vertical busses 16 by a connector which has contacts bearing on exposed sites on the film wiring. These vertical busses provide cable on printed circuit board chan nels.

Insulation displacement is used to terminate the ribbon cabling 18 to the same connector, thus providing a means of signal distribution to other parts of the system. The vertical buss channel is also used to retain the ribbon cable or distribution printed circuit.

Claims

1. An electrical equipment mounting ar rangement, in which circuit unit substrates are each mounted to a flat surface of a heat-sink or heat conductive metal wall be a flat washer of a thermally conductive soft material.

2. An arrangement as claimed in claim 1, and in which each said substrate and its washer are held against the heat sink or wall by fastener each located at the edge of a said substrate.

3. An arrangement as claimed in claim 2, in which there is a co-ordinate array of said substrates with compliant retainer strips each overlaying the edges of pairs of adjacent substrates.

4. An arrangement as claimed in claim 1, in which the power distribution was a multilayer plane mounted to but electrically insulated from the heat-sink or wall, and in which each said substrate and its washer is in a hole in said plane.

5. An electrical equipment mounting arrangement substantially as described with reference to Fig. 1 or Fig. 2 of the accompanying drawings.