Powcr dissipation, six and circuit dencity of intcgratcd circuit chip.; arc incrcasing and flip-chips are getting popular. Flip-chips may be joincd to the substrates using small soldcr balls (commonly known as controlled collapsc chip connections or C45) on thc circuit side of the chips, a n d are capable of providing a vcry large numbcr of input and output conncctions. Thi.; papcr dcsci ibcc a I atlial-fingcrcontact (RFC) spring for thcrmal cnhanccment of packages with C4 type flip-chips. This spring, in the shape of a disk, is made from a thin shcct of high conductivity coppcr alloy. A number of radial slots arc cut in an alternating pattcrn to make it flcxiblc. Tt is platcd with nickcl to prcvcnt coirosion and formcd into a domc shapc cuch that whcn placcd inside a flip-chip package it makes contact with the chip and thc cap, thus providing a dircct heat transfcr path from the back side of the chip to tlic cap.To establish the feasibility and thermal reliability of this concept, a numbcr of flip-chip packagcs werc built with ancl without the RFC spring and tested for thcrmal performancc.In onc set of packagcs with thc RFC springs, a silicone gcl was uscd a t the chip intcrface to furthcr improve the thcrmal performancc. Thc packages wcrc cxposed to a numbcr of accclcrated stresses and the packagc thcrmal pcrformancc (internal or the chip-to-case thcrinal resistance) was periodically measurcd. The results show that Yignificant improvement in thcrmal performancc is posciblc with the usc of the R F C cpring and thic rcmains stablc aftcr cxpocure to accelcratcd strcsses. Thi.; method of thermal enhancement is easily extcndable to multi-chip packages with flip-chips.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.