Title :
Multichip module packaging for cryogenic computers
Author :
Yamamoto, Haruhiko
Author_Institution :
Fujitsu Ltd., Tokyo, Japan
Abstract :
A high-speed multichip module for cryogenic data processing systems has been developed using new packaging and cooling techniques. The cryogenic multichip module achieves a cycle time of 1.5 ns by using high-speed high-electron-mobility-transistor (HEMT) ICs, low-stress cryo-multichip module (MCM) packaging, and a stable cryocooling system. The HEMT multichip module consists of 20 3 K-gate HEMT ICs on a high-density, 115-mm2 ceramic substrate. The chips are mounted by flip-chip bonding on a cryogenic ceramic multilayer substrate which has a thermal expansion coefficient similar to the HEMT GaAs material chip. The low-stress bonding material and cooling system are analyzed for reliability. Heat generated by the chip, which has a 12-W/cm2 heat flux and totals 100 W per module, is removed by LN2 (77 K) immersion boiling cooling. Dual refrigerators and a closed-loop system were used for reliability
Keywords :
III-V semiconductors; ceramics; cooling; field effect integrated circuits; flip-chip devices; gallium arsenide; high electron mobility transistors; hybrid integrated circuits; packaging; reliability; substrates; 1.5 ns; 100 W; 77 K; GaAs; HEMT; MCM; ceramic substrate; closed-loop system; cooling system; cooling techniques; cryocooling system; cryogenic computers; cycle time; dual refrigerators; flip-chip bonding; heat flux; high-electron-mobility-transistor; liquid N2 cooling; low-stress bonding; multichip module; multilayer substrate; packaging; reliability; semiconductors; thermal expansion coefficient; Bonding; Ceramics; Cooling; Cryogenics; Data processing; HEMTs; Multichip modules; Nonhomogeneous media; Packaging; Thermal expansion;
Conference_Titel :
Circuits and Systems, 1991., IEEE International Sympoisum on
Print_ISBN :
0-7803-0050-5
DOI :
10.1109/ISCAS.1991.176835
