Simple Analog ASIC Solves Thermal Analysis Problems

In a world where Application Specific Integrated Circuits (ASICs) and Application Specific Standard Products (ASSPs) are dominating every conceivable application, greater attention is being applied to their long term reliability. These chips are being built on smaller lithographies, running at higher speeds, dissipating more power and to make things worse, they are being encapsulated in ever decreasing package sizes.

Higher device performance comes at a price; higher temperatures. And with higher temperatures comes lower reliability if thermal considerations aren’t carefully controlled. Semiconductor manufacturers have long been aware of the problems associated with heat. Most have application notes and white papers plastered across their web sites espousing the benefits of careful calculation of power management using their values of [SUB]JA[/SUB] and [SUB]JC[/SUB] (Junction-to-Ambient and Junction-to-Case thermal resistance, respectively) often with sidebars suggesting various heat sinks to use in marginal situations. This puts the burden of solving temperature related problems on the backs of the user.

Recent technology advances and the proliferation of the use of Thermal Test Chips (TTCs) like those developed by JVD, Inc. for Thermal Engineering Associates of Santa Clara, CA is allowing semiconductor manufacturers and companies designing their own ASIC/ASSP devices to get ahead of the curve by thermally engineering their silicon before going to production. These TTCs allow system designers to fully model, measure and modify their designs before committing to costly silicon. They are special Analog ASIC that are used to model and measure the thermal performance of your chip design in situ before you commit those tooling dollars for masks and wafers. , the use of these Analog ASIC Thermal Test Chips play an important role in allowing semiconductor manufacturers and companies designing their own ASIC/ASSP devices to get ahead of the curve by thermally engineering their silicon before going to production.

Modeling allows you to create multiple individual heat sources on the TTC die, identical to the heat sources that will occur on your final IC. Temperature sensors, strategically located throughout the TTC give you precise measurement of the temperature of the die at multiple locations simultaneously. The heat sources can be modulated to replicate various portions of your IC being power on, off or in an intermediate mode. By tracking the absolute or changes in temperature at any point on the TTC, you can determine if one or more heat sources combine to exceed safe operating temperatures of the intended IC design. If temperatures are problematic, you can go back to your IC design and modify the chip?s layout to isolate the heat sources and alleviate the potential problem.

FULL WHITE PAPER HERE

Bob Frostholm – JVD, Inc.