Spray-On, Low Temperature Sintered Metallic Coating for Electromagnetic Shielding

There is an emerging need within military electronics for protection of electronics from the adverse effects of high power electromagnetic radiation. The Department of Defense has a requirement to ensure survivability of important military C3 and weaponssystems against the effects of electromagnetic weapons threats. What is needed is an electromagnetic hardening technology that is lightweight yet offers high shielding effectiveness and can be integrated into the system design, is low-cost,field-expedient, and transparent to the user. Transient liquid phase sintered (TLPS) conductive inks, now emerging as a low-cost approach to fabrication of printed wire boards, will fit all of these requirements if low-cost application methods, reducedsure/sinter temperatures and improved electromagnetic shielding properties can be achieved. TLPS inks comprise a combination of polymers and metal powders that fuse together at low temperatures to form a continuous metallic layer that bonds to commonsubstrate materials. The objective of this proposed efforts is to develop a spray-applied electromagnetic paint-shield with superior shielding effectiveness that sinters and cures at temperature well below those of current TLPS inks. This conductivepaint will allow low-cost shielding to be applied to just about any electronic device. The emergence of high-speed-information products is creating a need for new EMI shielding technologies that can be incorporated as part of the design of the tinypackages now emerging. What is needed is a method of shielding a digital or a RF signal from one point on a printed circuit to another. If a low-temperature cured, spray applied TLPS paint can be made, it will revolutionize the shielding of electronicsfor commercial and defense applications.