# US 5,343,940 A · Flexible heat transfer device

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- Number: US 5,343,940 A
- Document ID: US5343940A
- Status: Granted
- Kind: A
- Application number: 08/146,432
- Filed: 1993-10-29
- Granted: 1994-09-06
- Earliest claimed: 1992-10-29
- Inventors: Amigo Jean
- Web page: https://patentgrep.com/patent/US5343940A

## CPC

- H10W 40/73: for cooling by change of state
- F28D 15/0241: {the tubes being flexible}
- H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
- F28D: HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT (fluid heaters having heat generating means and heat transferring means F24H; furnaces F27; details of heat-exchange apparatus of general)

## Abstract

A flexible heat transfer device includes a closed flexible envelopment which is made of a plastic film and which has a receiving space provided therein. The envelopment has a first section and a second section spaced from the first section. The receiving space of the envelopment contains a heat transfer liquid which has a boiling point between a temperature of a heat source and an ambient temperature. Therefore, the heat transfer liquid in the first section of the envelopment is evaporated into a vapor when the first section of the envelopment contacts the heat source, and the vapor is condensed in the second section of the envelopment at the ambient temperature.

## Claims

### Claim 1

A flexible heat transfer device for dissipating heat from first and second electronic elements respectively mounted to first and second circuit boards disposed in a casing, the first circuit board disposed parallel to and below the second circuit board, the device comprising:
a plurality of heat dissipation plates disposed on an exterior portion of the casing above the first and second circuit boards;
a flexible envelopment defining a receiving space, the flexible envelopment formed as a flat tubular strip of plastic film comprising,
a lower section attached to the first electronic element and defining a lower portion of the receiving space,
an intermediate section attached to the second electronic element and defining an intermediate portion of the receiving space, and
an upper section attached to the dissipation plates and defining an upper portion of the receiving space;
a heat transfer fluid disposed within the receiving space and having a boiling point between an ambient temperature outside the casing and a desired temperature of the first and second electronic elements when active;
wherein the heat from the first and second elements respectively conducts through the lower and intermediate sections of the envelopment into the lower and intermediate portions of the receiving space and converts the fluid into a vapor;
wherein the vapor flows to and condenses in the upper portion of the receiving space, thereby transferring the heat through the upper section of the envelopment to the heat dissipation plates;
wherein the condensed vapor flows back to the intermediate and lower portions of the receiving space; and
whereby a reciprocal flow of the heat transfer liquid is formed between the upper portion and the intermediate and lower portions of the receiving space and the heat is transferred via the heat transfer fluid to the heat dissipation plates.