Unformatted text preview: tories Interior view of custom ‘hybrid’ package, wire bonding tier and die Integrated Microsystem Packaging Example Microsystems Packaging: An Introduction Page 82 © 2003 Sandia National Laboratories Integrated Microsystem Packaging Example
LTCC Lid Photodetector, mounted on lid SUMMiT V™ Microshutter VCSEL, mounted on base 90 Volt ASIC Brazed seal ring LTCC Base Electrical I/O pins Discrete electrical components mounted externally
Microsystems Packaging: An Introduction Page 83 © 2003 Sandia National Laboratories Most Common Packaging Mistakes
• Throwing the device over the wall (please package this…) • Using an extremely complex processing/packaging scheme
– Excessive processing of released die reduces yield – Bondpads smaller than 100 µm x 100 µm are difficult to work with • Process development is not free
– One success does not mean that process yield is 100% – Please don’t underestimate the time it will take to develop a process • Remember very little in MEMS packaging is standardized, most of it is application specific
Microsystems Packaging: An Introduction Page 84 © 2003 Sandia National Laboratories Reference Information on Qualifying Packages
• How do you know your package is OK?
– Military Standard 883: how to test microelectronics – As a publicly available standard, specific testing methods are supported by test equipment – Used in industry – Failure mechanisms well understood – SNL historically has done Mil-Spec packaging • Mil Spec Available On-Line:
– http://www.dscc.dla.mil/programs/milspec/default.asp – Search for: MIL-STD-883 – 7.7Mbyte PDF (658 pages)
Microsystems Packaging: An Introduction Page 85 © 2003 Sandia National Laboratories Glass Cap Design Rules
1. Autocad files of bonding rings are available via email from [email protected] 2. The width of the bonding ring should be 500µm or greater. This is set by our ability to machine glass and by the necessity to have a large bonding area. 3. If the wire bonding is done at the MDL, the space between the outside edge of the bond ring and the bond pads should be at least 700 µm for glass that is 1 mm thick. 4. At least 250 µm should separate the moving parts of the surface micromachine from the edge of the bonding ring. 5. The bonding ring must be connected to the substrate via a nitride cut. 6. Designers are urged to use restraints on springs and other parts that could be deflected during bonding. The electrostatic forces endured d...
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- Spring '10
- Semiconductor device fabrication, Wire Bonding, Sandia National Laboratories