Apparatus for encapsulating a semiconductor device
US5118271A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 22, 1991 |
| Grant date | Jun 2, 1992 |
| Priority date | — |
| Expiry date | Feb 22, 2011 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C70/72
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
An elastic material covering an outer surface of a cavity plate but not covering any clamping surfaces of the cavity plate or the inner surface of the cavity plate is used to eliminate use of a dam bar in a lead frame. In an embodiment in accordance with the present invention the elastic material provides a supplementary seal to the clamping surfaces of the cavity plate and a primary seal in spaces between leads of the encapsulated lead frame. In a method of using the present invention, the elastic material is placed between the mold base and the cavity plate. A semiconductor lead frame to be encapsulated is placed in cavities provided by the cavity plate. The mold is closed so that clamping surfaces of the cavity plate clamp directly onto the leads. The elastic material deforms under pressure to compensate for any dimensional variations of the mold plates or lead frame and completely seals the space between leads.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.