Flip chip assembly on rigid organic laminates: A production ready process for automotive electronics

In a succession of statistically designed experiments, simple material screening tests and product-specific mechanical emulators were employed to demonstrate enabling technologies that result in reliable processes for the attachment of flip chips to rigid organic printed-circuit boards for application in automotive electronic controllers. Investigations focused on the effects of critical process and design parameters on solder joint reliability. During the course of this multi-year effort, investigators assessed the system performance of numerous underfill epoxies, flux chemistries, cleaning agents, solder mask materials, and laminate constructions. More than 280 materials and assembly process combinations were evaluated. Results indicate that flip chip survivability in automotive environments is strongly dependent upon combined materials interactions and that reliability is system dependent. Furthermore, several flip chip assembly processes exceed system reliability requirements for automotive applications