Embedded Passive Technology Application: Design and Fabrication of an Automotive Engine Controller

This paper summarizes Delphi Electronics and Safety´s activities of design, fabrication, and testing of an automotive engine controller, which was used to demonstrate the feasibility of embedded passives technology. 3M C-Plyreg capacitive and DuPont ceramic resistive materials were used to make embedded capacitors and resistors respectively. The substrate is a 3.25 times 2.75 inch, eight-layer organic laminate board with minimum of 3 mil line/spacing, flip chips, microvias, embedded resistors and capacitors. 205 of 217 resistors of the controller were embedded with a buried rate of 94%. The resistors were designed for laser trimming with every resistor trimmed to a tolerance of plusmn2%. 13 decoupling caps and 12 filter caps were embedded as well. The substrates were assembled and functionally tested. The completed engine controllers were successfully in a vehicle application at speeds over 100 kilometer/h. Design rules, fabrication processes, technology hurdles, and future considerations are also discussed