Design of HWSI multichip modules for quick prototyping and manufacturing

The constraints imposed by the semicustom approach on multichip module designs are studied using a design case that interconnects a 144-input/output (I/O) microprocessor and four memory chips. The results show that semicustom hybrid wafer-scale-integration (HWSI) has enough real estate for complex designs even with the constraints on interconnection: a low inductance level (<0.2 nH) per power/ground (P/G) connection, even with an additional connection from a solder bump to a near thermal via; and alternative thermal management schemes to replace the ineffective thermal paths using solder bumps and thermal vias. These schemes use a custom-designed standard substrate for high-power chips, an alternative thermal path having enhanced gap conduction, or a compact immersion cooling design.<>