Temperature Rise Measurement due to Joule Heating in a Stamped Metal Land Grid Array Socket

摘要

Land grid array (LGA) sockets provide a solderless Printed Circuit Board (PCB) attachment method for microprocessors that require high interconnect densities. Stamped metal LGA sockets consist of metal contacts embedded in a plastic housing, that form the electrical and mechanical connection between the LGA component and PCB by means of compression.rnThe numbers of cores in a microprocessor has been increasing in recent years, placing demands for increased current-carrying capability on the interconnect. As greater currents pass through the interconnect, the temperature rise due to Joule heating is expected to accelerate failure mechanisms such as stress relaxation, cause melting of the surrounding polymer, or lead to a thermal runaway condition. The goal of this study is to determine the temperature rise due to Joule heating in stamped metal sockets, as close as possible to the powered contact. Measuring the temperature rise associated with current at a contact, allows failure models for appropriate thermally induced failure mechanisms to be applied and a risk assessment to be performed for the specific failure mechanism. In this study both temperature and resistance were monitored in a current induced aging test, which allowed detection of a thermal runaway condition at overstress currents. A temperature rise due to Joule heating was detected at an operating condition, but thermal equilibrium was quickly reached.