Flexible printed polymer lead frame
US5455394A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 27, 1993 |
| Grant date | Oct 3, 1995 |
| Priority date | — |
| Expiry date | Aug 27, 2013 |
Classification
- Technology area (CPC —)General
Abstract
A polymer lead frame is made from a flexible substrate with flexible conductive traces. The generally square lead frame has diagonal cutouts partially extending from the corners towards the center, as well as a central hole that lies within a footprint of the die. The die is bonded directly to the lead frame, preferably with anisotropic, electrically conductive adhesive. The die is placed with the lead frame in a fixture. A holding force is applied to secure the die and, if necessary, a curing force is applied during a cure cycle. The fixture allows transport of the assembly to a curing oven and allows application of the curing force. The die has contact pads characterized by a non-planar, non-bump-like surface with concavities having depths of at least about one-seventh the diameter of conductive particles in the anisotropic conductive adhesive.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.