Solderability of Injection Moldable Thermoset Resins for Use in 3D Mechatronic Integrated Devices

Increasing demands regarding reliability of mechatronic systems and the aim for miniaturization require new materials and processes for the 3D mechatronic interconnect devices (3DMID) technology to fulfill those demands. For the first time, this paper demonstrates the solderability of a new material class for 3D-MID applications, down to the SMD component size 01005. Instead of standard and state-of-the-art thermoplastic materials such as polyamide or high-performance thermoplastic materials commercial injection moldable thermoset resins were used. They were selectively metallized by laser structuring and electroless plating. Different laser parameters for structuring of two different substrate materials were investigated. SMD resistor components with the size 0805, 0402, 0201 and 01005 were used to evaluate material solderability on stencil printed solder pads. Specimen were analyzed using optical analysis, metallographic examination and shear tests. The results show that component size and laser energy have the most significant effect on shear strength and defects. Eligibility for common soldering processes in electronics packaging was proven. Additionally, soldering results between convection soldering and vapor phase soldering were compared, showing higher shear forces for samples soldered in the convection oven. Based on the results the tested injection moldable thermoset resins are suited as circuit carrier material in electronic packaging.