Bonding semiconductor chips to a mounting surface utilizing adhesive applied in starfish patterns
US4803124A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 14, 1987 |
| Grant date | Feb 7, 1989 |
| Priority date | — |
| Expiry date | Aug 14, 2007 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/24843
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method of bonding semiconductor chips to a mounting surface and a nozzle for same includes the steps of applying a first deposit of a die attach adhesive material to the mounting surface in a manner wherein the first deposit has the general shape of a starfish. This starfish shape is characterized by a raised central portion disposed at the intersection of the radially inner ends of a plurality of centrally thickened arms. The next step is to apply the bonding surface of a semiconductor chip against the deposit to cause the deposit to spread therebeneath while removing air pockets and hence any voids within the die attach adhesive material. The volume of the deposit being proportional to the surface area of the bonding surface and the configuration of the first deposit being defined to cause uniform and symmetrical spreading of the first deposite across the bonding surface provides full coverage of the bonding surface with a uniformly thick layer of adhesive. A die attach dispensing tool or nozzle includes a bottom shape including recessed portions whereby when the bottom of the tool is disposed in confronting relation to a mounting surface a flow passage carrying die attach adhe…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.