Temperature control during test and burn-in

Electronic devices are routinely tested multiple times during the manufacturing process: at the wafer level, at module level test and during module burn-in. The challenges of temperature control are significant because the devices are not yet fitted with a permanent heat sink; device powers may be very high and temperature specifications can be tight. Ideally, the thermal solution will provide excellent temperature control, be fast and easy to apply, will have indefinite life, and leave the device clean and dry. Cost, weight, noise and power consumption of the thermal solution are generally of secondary concern. High power thermal solutions typically consist of a passive or actively controlled, liquid-cooled heat sink temporarily pressed into contact with the silicon device surface. Methods have been developed to evaluate the thermal performance of these temporary heat sinks. Device-to-heat sink thermal interface resistance is evaluated with thermal test chips. Temperature gradients across the uniformly powered test chips are presented as a function of device power, heat loss into the socket, test temperature, heat sink force, centrality of the force and time.