RESEARCH AND APPLICATION OF A THERMAL MANAGEMENT DEVICE (CoolCap TM) FOR ELECTRONIC ASSEMBLIES

摘要

As the electronics industry is moving towards lead-free solders, most replacement alloys that have received serious o consideration have peak reflow temperatures of 20 C or higher than their lead-based counterpart. This is not surprising to most manufacturers and, in general, most companies do not have to modify assembly equipment (namely reflow ovens) to handle this change: what does become an issue, however, are heat-sensitive components. Many manufacturers, particularly contract electronics manufacturers, must deal with lead-based process compatible parts (a.k.a., legacy parts) that cannot be subjected to these higher temperature extremes. Cookson Electronics has developed a family of thermal management devices, known as “CoolCaps” to help protect heat-sensitive components during assembly and rework operations. A CoolCap is made of a hydrated inorganic material that contains bound water or a combination of both bound water and absorbed water and acts to protect (shield) a heat- sensitive component when it is in an environment (e.g., lead-free process temperatures) for which it was not originally designed. This work details recent materials research, performed to understand the operational envelope, particularly for the pick-and-place operation of CoolCaps. Experiments detailing the material’s process window in terms of its pick-and-place ability, thermal efficacy and mechanical strength with the use of different “additive materials” together with CoolCap results in protecting heat sensitive components are discussed.