Fabrication process and package design for use in a micro-machined seismometer or other device
US8978246B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 17, 2011 |
| Grant date | Mar 17, 2015 |
| Priority date | — |
| Expiry date | Aug 5, 2033 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49144
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method of attaching two wafers in a seismometer comprising the steps of forming a patterned wetting metal layer on a first wafer and forming a plurality of cavities mirroring the pattern of the wetting metal layer on the first wafer. The steps further include pouring a plurality of solder balls on the surface of an alignment wafer, pouring off excess solder balls, aligning the first wafer with the alignment wafer, and connecting the first wafer with the alignment wafer. The solder balls are immobilized on the wetting metal layer by performing a partial reflow onto the wetting metal layer and removing the alignment wafer. The first and second wafers are aligned so that each solder ball is immobilized between the first and second wafer. The wafers are then bonded together.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.