NL1042555B1

NL1042555B1 - Method for cooling electronic circuit boards by a flexible membrane

Info

Publication number: NL1042555B1
Application number: NL1042555A
Authority: NL
Inventors: Gijs-Willem Schoonderbeek Ing; Johannes Henricus Pragt Ir; Hiddo Hindrik Hanenburg Ing; Jetze Kuindersma Sjouke; Geert Gijlers Msc Hermannus
Original assignee: Stichting Astron Netherlands Inst For Radio Astronomy
Priority date: 2017-10-04
Filing date: 2017-10-04
Publication date: 2019-04-11

Abstract

Method for cooling an electronic component (2) or electron ic assembly by a liquid flow (5), separated to the said electronic component or assembly by a thin flexible foil (3) what is fixated and/or sealed by a holder under pres sure. A thermal conductive buffer may be placed between the foil and the electronic component or electronic assembly to cover sharp edges of the electronic components or electron- ic assembly. A thermal conductive buffer may be placed be tween the foil and the electronic component or electronic assembly to reduce the height differences of individual cooled components.

Description

Title: Method for cooling electronic circuit boards by a f1ex ib1e membrane

DESCRIPTION

The invention refers to a method for cooling electronic circuit boards.

Background of the invention

Modern electronics boards are becoming more n 1 con plex. The heat dissipation of the components ana t no for more components in a small space makes it difficult to cool with air. Liquid cooling can solve the problem. Usually a liquid piping or tubing circuit on the board is used to conduct the liquid to cooling pads that are connected to the components to be cooled. Exchange of the electronics boards, however, needs for c1osing and discοηnecting sever-al tubes or pipes. This results in a risk that, the electronics is exposed to spills of the cooling liquid. Special self-closing liquid connectors may be used. These, however, are expensive and have a need for high mating forces. This results in high stresses in the electronics board.

The present invention aims to avoid the ''x '\cc, v.l ing pads and piping or tubing, to avoid dedicated parts and spaces for mounting the cooling pads, and to avoid the high stresses in the electronics board due to the use of liquid connectors.

De s c r i ρ t i o n o f t 'n e i n v e n t i ο n

According to the invention a vessel is used with at least one thin and flexible surface. The vessel contains a liquid and is part of a liquid cooling circuit. The flexible surface is pressed to trie components to be cooled. Due to its flexibility the surface accommodates to differences in ske, position and height of the components, The heat dis-. pr : + no t '+' o" ;c ' u r ..- 1 ’ u ο xa r the thin flexible surface to the cooling liquid inside the vessel. The . ' .. ' a structural part of the electronics board.. The elect ionics board can be exchanged without disconnecting the liquid circuit thus avoiding the risk of liquid spill over the electronics board. A typical flexible surface what can be applied is kapton foil (hitfre.dr én . wj^d.:ped.ig..Q-O fwithlf) . Also pBhem materials are suitable like polyurethane of silicon foil.

The circuit board may be cooled from one side (figure 1) or from both sides (figure 2). An arrangement of multiple boards may be cooled from both sides by vessels with two or more flexible surfaces (figure 3).

The method a \\ ί, ij rhe present invention provides: - adaptation to the different surface heights of the electronic components or electronic assemblies to be cooled without customized preforms; - interchange of electronic circuit boards without opening the liquid circuit; - cooling of electronic circuit boards with low mechanical stress on trit components; assemblies without a liquid circuit on the electronics board. Ά buffer rtiay be placed between the hot components and the foil in order to smoothen sharp edges and/or to overcome large height differences between the components. This can be an overall buffer or a buffer what is just covering a part of the cooled surfaces. E.g. the big flat 10 on a pcb, creating most of the heating power., may be not covered to have the best cooling power for that component., while the area around this 10 is covered with a thin conduct. i ve soft flexible foil like special silicon material, which cools the peripheral components having lower energy per area.

Figure 1 shows a circuit board cooled from one side;

Figure 2 shows a circuit board cooled from both sides;

Figure 3 shows an arrangement of multiple boards cooled frori! both sides by vessels with two or more flexible surfaces.

1 printed circuit board (peb) 2 component s 3 r iambi at e · rt -_1 4 ca sing 5 cooling liquid 6 cold liquid IM

T hot liquid OUT

The invention could be summarized by the following points; MU'. s s' s’ m ; u «. uo an a t < t . u ' m: * ’’ ·> < . ' 'u v v . liquid flow ¢5) r sepa™ rated to the .said electronic component or assembly by a thin flexible foil (3) what is fixated and/or sealed by a holder under pressure. 2, The method or system according to point 1, wherein a thermal conductive buffer is placed between the foil ' ' ' t ' v w ' ' v. t ·. ' . '; >. u t' ' v cover sharp edges of the electronic components or elec-trοnic a ssemb1y. 3. The method or system according to point 1 or 2, wherein a thermal conductive buffer is placed between the foil and the electronic component or electronic assembly to reduce the height differences of individual cooled components . . r ' ' '. >v h< > . ' s\ , t 'm λ \ ' ":.e u -. «. . .."ww ;\ 'v .· wherein a flexible foil is located at each side of the electronic component; or electronic assembly, cooling two sides of the electronic components or electronic as sembiy. 5» The method or system according to any preceding point, wherein two flexible foils are located at each side of holder under pressure, cooling two different electronic 6> The method or system according to any preceding point, wherein alternately an electronic component or electronic assembly and a foil cooling holder is creating a multiple stack.

Claims

Method or system for cows an electronic component (2) or electronic assembly by a technical component or assembly by a thin flexible film (3) fixed and / or sealed by a container under pressure. The method or system of claim 1, wherein a thermally conductive buffer is disposed between the foil and the electronic component or electronic interplay to cover sharp edges of the electronic components or electronic assembly. 3 :. Method or system according to claim 1 or 2, wherein a thermally conductive buffer is placed between the foil and the electronic component or electronic assembly to compensate for the differences in height of individual areas. 4.x Method or system as claimed in any of the foregoing claims, wherein a flexible foil on either side of '<' k. : o 5 'l v v' K 'l · v' t u y '' Uk. where two sides of the electronic components or electronic assembly are cooled. 5; Method or system as claimed in any of the foregoing claims, wherein two flexible foils are located under pressure on each side of the container, which two different electronic components or electronic λ '"<.

A method or system according to any one of the preceding claims, wherein an electronic component or electronic semens counter and a foil cooling container alternately form a multiple stack.