Method for making conduction-cooled circuit package
US4034468A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 3, 1976 |
| Grant date | Jul 12, 1977 |
| Priority date | — |
| Expiry date | Sep 3, 1996 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49117
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method for making a circuit package which exhibits an excellent heat transfer path from a semiconductor chip or other heat generating device to the heat sink can or cover of the package. A heat conducting pad is placed in proximate relationship to either the heat sink or to a surface of the chip and is metallurgically bonded to the other. In one of the preferred embodiments a low melting point solder, such as indium or an alloy thereof, is metallurgically bonded to the inside of the heat sink cover in a limited central region thereof. The solder is then positioned adjacent the chip and reflowed to substantially fill in the gap between the solder and the chip, but with no stress between the chip and the solder. The assembly exhibits excellent heat transfer from the chip to the cover and any associated heat dissipating structures. The preferred method involves the reflow of a mass of solder against the back side of the chip, which has previously been solder-bonded on the front side to conductors on the surface of an alumina substrate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.