Process-Consistency in Printed Layers in Multi-Layer Substrate Using Aerosol Jet Technology

Abstract

Interest in the field of additively printed electronics has grown owing to added flexibility with design and manufacture of parts in low volumes and lower time between design and prototype. The ability to directly print on a number of substrates, whether be rigid, flexible, or conformable, brings many advantages over traditional techniques used for electronics fabrication. Mainstream digital printing techniques include aerosol-jet, inkjet, dispense-on-demand, gravure offset are becoming more and more well known in the field of printed electronics, each having its own merit. In addition, given the fact that electronic systems are fundamentally multi-material, it is important to understand the material-material interaction including their compatibility, curing conditions, adhesion. Aerosol Jet technology supports a wide range of materials, viscosity ranging from 1cP – 1000cP. It involves use of two atomization processes: Ultrasonic Atomizer (UA) for materials with low range of viscosity (1-5cP); and Pneumatic Atomizer (PA) for higher range (1-1000cP). In multi-material printing, additional problems need to be addressed including degradation in the printed base layer from curing while printing a multilayer substrate. This paper provides an insight gained from investigations for the curing profile for all the layers. The materials chosen for the study are such that both the ultrasonic and pneumatic atomizers can be used simultaneously without having to remove after printing. With that in mind, a Silver Nanoparticle ink as a conducting material is used with low viscosity suitable for UA, and a dielectric as an insulating material with high viscosity suitable for PA. The dielectric will be used in the areas needed only. Process parameters will be developed for a multi-layer substrate, and the consistency of in the printed lines is addressed. In addition, process capability using statistical measures is performed. This results from this study will help gain more understanding into the problems that are not clearly visible while manufacturing a printed multi-layer substrate with vias through Aerosol Jet.