Evaluating thermoset resin substrates for 3D mechatronic integrated devices and packaging

Abstract Miniaturization efforts and increasing demands regarding reliability of mechatronic systems require new materials and processes for the 3D mechatronic integrated devices (3D-MID) technology. Currently, in the area of 3D-MID mostly thermoplastic materials are in use in the industry, which are metallized using the LPKF-LDS® process. This paper is supposed to demonstrate the eligibility of thermoset resins as a new material class for 3D-MID applications and as a packaging option for silicon chips which are currently encapsulated using transfer molding of thermosets. The reliability of the conductor tracks made using a LDS-additive free process as well as the adhesion forces are investigated. Different laser parameters for structuring of two different substrate materials are compared. For reliability testing a thermal shock test is applied. Furthermore, the adhesion is tested using Hot-Pin-Pull testing. The conductor tracks surpass 2000 cycles thermo-mechanical load without showing strong deterioration of the track resistivity. The incorporated approach enables electrically reliable functionalization of packaged dummy chips including vias for connection to terminals on the chips. The results of the tested injection moldable thermoset resins are comparable to state-of-the-art 3D-MID thermoplastic substrates and thus, suited as circuit carrier material in electronic packaging.