Designing Ring Projections for Hermetic Sealing

This guide details the design and implementation of ring projections for hermetic sealing in electronic packaging. It outlines the importance of selecting the appropriate pneumatic weld head controller, weld head, and power supply to ensure effective sealing. The document explains that ring projections can be coined, machined, or chemically etched into the package header or lid, emphasizing that the projection should be on either the cap or the header. It discusses the typical height for projections and the need for co-planarity to avoid non-hermetic seals due to uneven heat distribution. The guide also presents the significance of developing a proper weld schedule, which balances force, heat, and weld current through methodical adjustments. Additionally, it highlights the use of visual indicators and weld monitors to ensure reliable hermetic seals, along with the importance of post-weld defect checks. The document concludes by stressing the need for thorough evaluations of specific processes to enhance manufacturability.