Wafer fabrication of inside-wrapped contacts for electronic devices
US5904496A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 24, 1997 |
| Grant date | May 18, 1999 |
| Priority date | — |
| Expiry date | Jan 24, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/30107
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A packaging technique for electronic devices includes wafer fabrication of contacts that wrap down the inside surface of a substrate post. Inherently reliable contacts suitable for a variety of devices can be formed, via a simple fabrication process, with good wafer packing density. A trench is formed in the top surface of a substrate parallel to the edge of its electronic circuit. A gold beam wire extends from a connection point within the circuit into the trench. Unless an insulative substrate is used, the wire runs over an insulating layer that ends part way through the trench. After epoxy encapsulating the top of the substrate, it is back planed to form the bottom surface of the post. Then it is selectively back etched, to expose the bottom surface of the wire, to form the inside surface of the post, and to form the bottom surface of the finished device. A solderable lead wire runs from the exposed gold wire, down the inside surface of the post, and across its bottom. Sawing forms the outside surface of the post and completes the finished device without subsequent assembly. Alternatively, no post is used and the contact comprises an encapsulant protrusion, similarly formed in a…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.