High Strength Flexible Adhesives for Environmentally Demanding Rigid-Flex Circuitry

Rigid-flex printed circuits consist of a rigid and flexible electrical laminates sandwiched together to form a composite structure having both rigidity and flexibility. They are attractive for commercial and military high performance applications because size and weight is reduced while reliability is increased. The adhesives utilized in these circuits play a central role in determining the reliability of the rigid-flex circuit. Meeting the thermomechanical stress requirements of military and complex commercial applications is a problem with current adhesives. Several hurdles exist: inadequate bond strengths after thermal cycling, inadequate flexibility where thermal cycling is required, low resistance to decomposition, low dielectric strengths, large Z-axis coefficients of thermal expansion, moisture absorption, low resistance to chemical attack and high costs. This proposal entails the development of new flexible co-polymer adhesives based on newly discovered polyester oligimers which can have higher bond strengths, higher operating and decomposition temperatures, lower coefficients of thermal expansion, and higher flexibility. The adhesives should retain superior properties, even under sever thermal and environmental conditions and should be processable by established processes and equipment. The Phase I objective is to prove the principle of a multifunctional epoxy polyester oligimer co-polymers to bond laminate components of a rigid-flex circuit together. OPTION: $20,008