Authors: Robert L. Hubbard, Ph.D. Company: Lambda Technologies, Inc. Date Published: 10/23/2018
IWLPC (Wafer-Level Packaging)
Abstract: To avoid material stresses in fan-out wafer-level and panel-level packages that create warpage, cracking, delamination, and thermal instabilities, the use of CTE matching and the lowest possible process temperatures has been a focus with this technology. Data is provided to show that this approach is actually causing more stress and crack propagation than is necessary especially for large wafers and panels. An understanding of the source of these chemical, mechanical, and thermal instabilities is offered with methods for avoiding these issues. Reduced warpage and bow, increased fracture energies, and wide-area film uniformity data will be shown to be possible on the largest of substrates with the use of low temperature curing by variable frequency microwave curing. A method is also described for increasing the speed and reducing the cure temperature even further with customized resins.