Additively Manufactured Near Chip Scale Interposers for DC and RF Applications

Additive manufacturing (AM) techniques for printed electronics (PE) have several benefits over traditional manufacturing, namely the reduction of waste material and the increased efficiency in producing rapid prototypes. However, there are disadvantages associated with AM, including, low throughput of parts. Limited research has been done to increase the throughput to the scale of traditional manufacturing methods. A hybrid approach to manufacturing will be presented. Initially, the interposer is printed via Fused Deposition Modelling (FDM). Polyether Ether Ketone (PEEK) was selected as the thermoplastic filament due to its desirable thermal properties while providing acceptable dielectric loss. A process control scheme was developed to not only track the quality of the printed interposers, but to monitor the performance of the nScrypt. The layer-by-layer method of extrusion, characteristic of FDM printing, inherently creates roughness on the sides of a 3D printed part. To alleviate this issue, a planarizing layer was additively deposited onto the desired print surface of the interposer to reduce the roughness to an acceptable level for the printed silver traces. Once the interposers were planarized, A 5-axis aerosol jet printer, with a patented custom holder, was used to print the silver traces that wrap around the interposer. The finished part, which is fully additively manufactured, is installed into a PCB that is manufactured using traditional PCB methods. The interposer assembly provides a DC connection from the printed traces on the interposer to the traces on the PCB. Details of the print processes, measurements of the performance of the device, along with material and device characterization will be presented.