Method for bonding heat sinks to overmolds and device formed thereby
US6206997A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 11, 1999 |
| Grant date | Mar 27, 2001 |
| Priority date | — |
| Expiry date | Feb 11, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/15311
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method for bonding heat sinks to packaged electronic components comprises the steps of: (a) exposing to a plasma a surface of a molded polymer formed on a substrate; (b) allowing the plasma to at least partially convert silicon-containing residue on the surface to silica; and (c) bonding an article to the surface by applying an adherent material between the article and the surface. Often, the silicon-containing residue is silicone oil, a mold release compound, which may prevent the formation of a bond when using conventional bonding methods and materials. The silica layer formed on the surface of the molded polymer assists in formation of a proper bond. The plasma may be an oxygen plasma and the adherent material may be selected from either a heat cured silicone-based paste adhesive with a metal oxide filler or a heat cured porous polymer film impregnated with adhesive. In particular, the film may be polytetrafluoroethylene, the adhesive may be polybutadine, and the film may be further impregnated with a metal oxide heat transfer medium, such as zinc oxide. An alternate method comprises applying the porous polymer film without plasma treatment and heat curing the film to form a p…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.