Aqueous Washable Thermal Resistant Coatings and Adhesives

Abstract

Abstract Many packaging processes require thin and fragile components to be protected or held securely in place for temporary periods of time. The most common process flow is to: apply the coating, cure or use to bond a device, conduct the process, and finish with removing the coating by washing in a liquid chemistry. Aqueous cleaning is deemed safer for devices on organic laminates and in the presence of molding compounds. These reagents use water as their major constituent. They are compatible with organic substrates (panels, laminates, boards), are worker safe, and require less expensive operating equipment. Aqueous washing is generally green and exempt from the complexity and cost of environmental and waste management regulations. Daetec's washable coatings qualify as green, and exhibit thermal resistance over 300°C, making them one of the most unique materials on the market. These coatings enable soldering, laser processing, plasma etching, and dielectric curing, all following with simple water washing. Water washable DaeCoatTM 525 is a key choice in laser processing for debris removal around the heat activation zone (HAZ), while the etch-resistant DaeCoatTM 534 supports laser patterning for plasma singulation [1]. While DaeCoatTM 532 is water soluble, another material from the same family, DaeCoatTM 537 is not, yet will wash away in an aqueous surfactant, DaeClean™ S20 (10% in water). In many ways, these products act, as surfactants, but depending upon the chemistry, will dissolve in water or an aqueous agent. Customers desiring a green protective coating or adhesive for plating or etching processes, may apply DaeCoatTM 537, send through the processes, and then wash away in the S20 aqueous agent. All products are cast from water. Film forms as 50μm thick with peel away liners are available for DaeCoatTM 532 and 537. UV curable high solids versions are also available. Applications include planarizing coatings, adhesive for die solder attach, and C4 or micro bump protection. Protective coatings for EMI/RFI shielding, dicing operations, and temporary bonding operations that may use porous carriers have been demonstrated with water washable coatings and adhesives. The success in these and related temporary applications depend upon the use of the proper washable coating. Our experience in creating solutions for these and other industry needs will be discussed as well as the criteria for using temporary washable coatings.