Additively Printed Multilayer Substrate Using Aerosol-Jet Technique

Abstract

Printing technologies, such as aerosol-jet, open possibilities of miniaturizing interconnects and designing circuits on nonplanar surfaces. Aerosol-jet is a direct-printing technique that provides an alternative manufacturing option to traditional subtractive methods that entail lithography or etching. Additionally, the aerosol-jet technique allows the circuits fabrication using noncontact method. Wide impact areas range from healthcare to wearables to future automotive applications. The aerosol-jet printer from Optomec utilized in this study consists of two types of atomizers, depending on ink viscosity. The ultrasonic atomizer, supports ink with a viscosity range of 1–5 cP, and the pneumatic atomizer that has a larger range of 1–1000 cP. This paper focuses on utilizing the aerosol-jet technique, using both atomizers to develop process parameters, in order to successfully print bimaterial, multilayer circuitry. The insulating material between two conductive lines used in the paper is of very high viscosity of 350 cP, which is suitable for the pneumatic atomizer and silver nanoparticle ink with comparatively low viscosity of 30 cP for the ultrasonic atomizer as a conductive ink. This paper also presents a statistical modeling approach that predicts line attributes, including microvia-diameter, before starting the print process, enabling us to pre-adjust the dimensions in computer-aided design for the desired output. Process parameters can obtain a fine print with satisfactory electrical properties, which develops improved dimensional accuracy. The importance of precleaning the substrate in addition to the printing process efficiency gaged as a function of process capability index and process capability ratio is also presented.