Wafer level packaging method and devices formed
US6197613A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 23, 1999 |
| Grant date | Mar 6, 2001 |
| Priority date | — |
| Expiry date | Mar 23, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/14
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
The present invention discloses a method for forming a wafer level package by first providing a silicon wafer that has a multiplicity of IC dies formed on a top surface, each of the IC dies has at least one peripheral I/O pad formed in an insulating layer, then forming at least one via plug of a conductive metal with a top surface exposed on the at least one peripheral I/O pad, then coating a layer of an insulating material that has sufficient elasticity on the surface of the wafer prior to the deposition and forming of a metal trace on the elastic material layer, at least one area array I/O pad is then formed at an opposite end of the metal trace with a solder bump formed on the I/O pad before they are reflowed into a solder ball. The elastic material layer deposited under the metal traces acts as a stress-buffing layer such that an IC circuit of high reliability can be produced on a wafer level for the low cost fabrication of IC assembly.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.