Transient thermal behaviour of a board-mounted 160-lead plastic quad flat pack

摘要

Severe transient thermal effects are induced in electronic components during assembly, reliability testing and operation. Although component reliability is a strong function of temperature, there is no absolute relationship to describe its dependency on the environmental conditions imposed by these processes. In this paper, the thermal response of a board-mounted 160-lead plastic quad flat pack to typical reliability test environments was investigated experimentally. The steady state thermal performance of the component in forced convection, and its unsteady response to air temperature cycling, power cycling and a combination of these were evaluated. The effects of various test cycle configurations, consisting of different air temperature ramp rates, dwell times, power level and air velocity, on the component response are clearly shown.