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102 DESIGN007 MAGAZINE I MAY 2021 ics assembly during its life occurs during the soldering process, which might happen two, three, or more times during assembly. is can be followed by rework which further degrades the electronics, so approaches that eliminate high temperature exposure (including pursuit of low temperature solders) are "low hanging fruit" from a targeting standpoint. However, the thermal problem doesn't end there. Heat of operation is another ongoing problem faced by the industry, and QFNs, as attractive as they are, are one of the more vul- nerable component types. Over the last sev- eral years, QFNs are being increasingly called upon to address electronic module design due to their minimalist size and performance ben- efit, but making full solder connection to the thermal pad on the bottom of QFNs has been one of the more vexing problems facing assem- blers. us for the balance of this article, QFNs will be used as exemplar components for this brief discussion and description of a method for building an electronic module that is, in and of itself, a thermal spreader. e series of story board graphics and their accompanying descriptions that together accompany this dis- cussion are provided as a word picture to allow the reader to quickly grasp these concepts. Illustration of the 12-Step Occam Process Prepare aluminum carrier with cavities to accept packages and tested components. Note: Alumi- num can be electrophoretically coated with epoxy or anodized . The base can also be molded or machined of insulating material or copper-clad laminate, if desired , and can be prepared to provide power and ground layers with additional circuitry, if desired , for the design. Place and bond components in cavities with copper terminations up. Note: Vent holes can be provided in aluminum base to help planarize components. 1: 2: