Abstract :
On high-density-mounting circuit boards, heat generated in the junction of the VLSI IC flows through the package to the printed-circuit card, heats up the lead pins of the surrounding VLSIs, and raises their junction temperature Tj. The conventional thermal resistance between the junction and ambient air, θj-a, cannot be used to estimate these thermal effects. A quantity representing the thermal resistance between the junction and the surface, θj-s, which can deal with these effects, is proposed. An analysis approach that allows Tj of surface-mounted devices to be predicted using measured surface temperatures is described. Experimental results that are in good agreement with theory are presented
Keywords :
printed circuits; surface mount technology; thermal analysis; thermal resistance; SMD; SMT; VLSI IC package heat generation; circuit boards; high density mounting technology; printed-circuit card; surface temperatures; surface-mounted devices; thermal evaluation; thermal resistance; Electric resistance; Heat transfer; Lead; Packaging; Printed circuits; Proposals; Resistance heating; Temperature; Thermal conductivity; Thermal resistance;
