Novel Approach on Application Manufacturing Using Inkjet Printing, Laser Ablation and New Polymer Substrate

Printed electronics is considered one of the emerging technologies in electronics manufacturing and packaging industry. Utilization of inkjet printing has been studied at Tampere University of Technology in cooperation with the Technical Research Centre of Finland (VTT). The target of this project was to manufacture an existing application by substituting traditional manufacturing processes and materials with additive inkjet printing and a novel polymer substrate. The substrate material was developed by VTT. The base material of the test substrates was a new high temperature thermoplastic Polyphenylenesulphide (PPS) - Polyphenylene oxide (PPO) compound. This compound has a good wide-ranging property profile for electrical applications, e.g., low dielectric permittivity and dielectric losses, high modulus at elevated temperatures and a low melt viscosity suitable for injection moulding. The surface energy of the substrates was increased by a corona treatment. The designed application includes unique features in terms of additive electronics manufacturing solutions. Laser ablation is used to create vias through the polymer substrate. While multilayer structures can be created by printing a dielectric layer between two conductive layers, in this case another approach was preferred. Vias were made through the substrate to use both sides of the substrate instead of printed multilayer structures. All interconnections are inkjet printed using inorganic silver nano ink. Isotropically conductive adhesive was used to create electrical paths through the vias as well as to attach discrete components to the substrate. This study discusses both benefits and challenges of the additive approach and novel substrate material use in specific application manufacturing.