Digitally-Driven Hybrid Manufacture of Ceramic Thick-Film Substrates

Ceramic substrates are commonly used in the electronics industry across a range of applications such as automotive, aerospace, industrial monitoring, power electronics and electromagnetic devices due to their ability to withstand high temperatures, pressures, radiation and mechanical shock. This paper will present the development of a new digitallydriven hybrid manufacturing process which overcomes many of the current limitations of stand-alone Additive Manufacturing for the production of precision engineered ceramic substrates and packages. This is achieved by interleaving ceramic paste extrusion with sacrificial support printing and micro-machining to produce a three-dimensional ceramic green-state part. A number of substrates were fabricated using a high viscosity, non-Newtonian paste consisting of 96wt% alumina. Thermally processing the substrate at temperatures in excess of 1400°C yields a monolithic ceramic substrate with resultant shrinkages of -18% and part densities of -99.8%. The 3D ceramic part is then processed using computer-controlled equipment to selectively dispense a conformal circuit using silver thick film conductor paste, followed by solder dispensing and pick and place surface mount assembly of components. This fully digitally driven approach enables new design freedoms and customization currently not possible with conventional template driven manufacturing methods of ceramic electronic packages.