Unformatted text preview: von Arx, University of Michigan Release Process Issues
• SUMMiT™ release in an HF solution
– Long release times
Change in Contact Angle (Θ i-Θ f) – Obey design rules on etch release holes! 60 50 40 30 20 10 0 -10 220 260 300 340 380 420 460 500 540 580 Temperature (C) Chemical A Chemical D Si3 • Drying options:
– Air dry – SAM coating to make hydrophobic – Supercritical CO2 – Sublimation drying • Coatings:
– SAM coatings – Wear resistant coatings
Microsystems Packaging: An Introduction Page 72 © 2003 Sandia National Laboratories temperature dependence of the contact angle of a SAMS coated surface as a function of temperature Advanced Design Issues: Die Separation
• Separate before or after release? • If after release, how to protect during separation?
– Glass cap – Area around MEMS for temporary protection – Get scribe and break to work • If before release, how are you measuring yield?
– Can’t do wafer level test, so then what? • Chip layout on wafer, die size, etc.
Microsystems Packaging: An Introduction Page 73 © 2003 Sandia National Laboratories Bulk Micromachined Infrared Imager
• Micromachined first • Then break • Then package
Device from Dexter Research Center Inc. Microsystems Packaging: An Introduction Page 74 © 2003 Sandia National Laboratories Alternative Die Separation and Handling Technique (Design Rules at End of Handout)
• Package MEMS at the wafer level • Then dice and handle them like regular IC die Microsystems Packaging: An Introduction Page 75 © 2003 Sandia National Laboratories Design for “Packagability” of MEMS:
• The developer of a MEMS device desires...
– a large number of functional, testable, packaged parts – devices that can be operated in a manner that yields useful information for yield/design enhancement • SUMMiT V™ MEMS
– need free space to operate – have polysilicon pads for wirebond interconnections – It is logical to assume that these devices will end up in some sort of cavity package (cerdip, TO, etc.) • Sandia has high-rel packaging experience
– We like ceramic packages with brazed-on lids
Microsystems Packaging: An Introduction Page 76 © 2003 Sandia National Laboratories Your Design Includes the Package!
• As part of the design process, the in...
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- Spring '10
- Semiconductor device fabrication, Wire Bonding, Sandia National Laboratories