Managing Voids in Adhesives for Medical Devices

Abstract

Void content within the adhesive layer dispensed over the connector module in neuromodulation devices is critical. Voids can affect the thermal transfer, bond strength, and stress decoupling of the adhesive, which can eventually lead to degraded device reliability. The effects of voids are investigated for a silicone based adhesive used in these medical devices. There are many challenges associated with the curing process that this adhesive undergoes which drive the need for unique and specific testing to determine optimal process settings. The parameters evaluated included curing time, temperature, thickness, and relative humidity. Reduction in void content was linked with mechanical properties including hardness and tensile strength. Achievement of void free medical adhesives will encourage today's microelectronic packaging industry to meet the challenges of smaller and denser medical devices.