Ablestik self-filleting die attach products from Henkel incorporate a self-filleting mechanism to create a cost-effective alternative to die-attach films. Until recently, die-attach films were the only option to achieve bonding thicknesses down to 5µm. However, self-filleting die-attach pastes accomplish this without requiring changes to current equipment sets or process steps at a reportedly reduced cost-of-use than die-attach film.
While conventional die attach pastes can be hard to control when trying to meet package requirements of thinner die with tighter tolerances, this novel technology uses capillary force to control flow and deliver complete wetting. Instead of complicated, precise dispense patterns combined with die placement force to encourage flow, determine bondline thickness, and promote wetting, these self-filleting pastes use capillary function to control these critical process parameters through dispense volume and spacer technology.
Using traditional automatic dispense technology, material is deposited and the die gently placed. The material’s capillary force draws it out to the edge of the die where it forms a small fillet. No excessive placement force is required, which eliminates die damage while also allowing for extremely tight process control. The materials are available in three formulations: non-conductive paste for die-to-substrate laminate-based devices; non-conductive material for die-to-die attachment, including same size, pyramidal and orthogonal die stack packages; and conductive adhesive designed for die-to-substrate leadframe packages. Henkel Corp. Irvine, CA; www.henkel.com/electronics.