Rapid On-Substrate Curing of Thick Protective Package Sealing for Automotive Assembly

Abstract

Protective encapsulant and sealing materials that cure upon delivery are desired for high volume automotive assembly. Unlike many coatings created for electronics, these materials are milimeters thick and have desirable elastomeric properties to withstand decades of stress. While the Automotive Electronics Council (AEC) stress test qualification for integrated circuits (AEC Q100, 1994) may set material temperature resistance at 150C, targets of 200C or 250C are desirable. The ideal polymer exhibits low permeability, effectively creating a barrier to moisture, chemicals, and gases that may emanate anywhere on the chassis. While conventional Buna and Viton rubbers represent a major share of gasketing to protect electronic packages, their design and manufacturing infrastructure cannot meet the pace of prototyping. Polymer compositing with reactive diluents now makes it possible to use CAD fed delivery tools that cure on-contact. Such robotic operated equipment delivers by variable syringe head design on vertical, overhead, or irregular surface contours. Sealant forms that once took months with costly quantity orders, now take seconds in the lab and on the assembly floor. Daetec has created a technology that meets these rapid assembly requirements with properties that exceed the current AEC targets. A complete process will be presented with state of the art LED fiber optic curing on the substrate. Data and application results using comparative specimens will be presented.