Additive Manufacturing Processes
Direct Write Processes
This article is a detailed account of the advantages, disadvantages, and applications of microdispensing processes used in electronics manufacturing industries. The discussion covers various approaches to control material flow, namely time pressure, auger, positive displacement, and progressive cavity pump dispensing. The concept of valving to control starting and stopping is also discussed. The applications include printing solders in microelectronic packaging, printing to pads, printing conductive patterns for antennas, printing active circuits, printing on flexible surfaces, and structural printing.
Aerosol jet printing (AJP) can digitally fabricate intricate patterns on conformal surfaces with applications that include flexible electronics and antennas on complex geometries. Given the potential performance and economic benefits, aerosol jetting was studied and compared with the well-known and competing inkjet printing (IJP). More than 35 of the most relevant, highly cited articles were reviewed, focusing on applications requiring fine features on complex surfaces. The following performance indicators were considered for the comparison of AJP and IJP, because these aspects were the most commonly mentioned within the included articles and were identified as being the most relevant for a comprehensive performance assessment: printing process, line width, overspray, complex surface compatibility, diversity of printable materials, and deposition rate. This article is an account of the results of this comparison study in terms of printing capabilities, ink requirements, and economic aspects.