Printing electronics
The page is an attempt to collect all developments relating to fabricating circuit boards and electronic components.
Contents
Motivation
- Bruce Perens says we at least need macro-scale diodes to back some of the claims of changing the world. http://technocrat.net/d/2008/6/5/42592/
- At least one computer engineering student thinks it would be wonderful to be able to prototype application specific integrated circuits from home.
Challenges
Unsuitable Conventional Processes
The conventional circuit board fabrication process is very involved, and for time and simplicity, fewer steps and chemicals would be good. Ideally, one shouldn't need a cleanroom to be able to use a RepRap to its full potential. That probably throws out photo-lithographic processes for smaller than macro scale. Also, particle acceleration takes too much energy to be reasonable, so ion implantation as a doping method is probably also unrealistic.
Toxicity
Ideally, the chemicals used by the RapRap won't hurt living things. Eutectic alloys, etching chemicals, semiconductors and dopants all should be carefully examined and selected to be non-hazardous, where possible. Some toxic chemicals used in the semiconductor industry include lead, cadmium, arsenic, and phosphorous. In some cases, such as using cadmium in photovoltaic cells, there may not be very good alternatives, and proper personal protection mechanisms and recycling should be developed.
Circuit boards / Wiring / Traces
See also: Automated Circuitry Making and Plotting. Also, part of the Gada Prize is the ability to print at least three different materials, one or more of which is electrically conductive.
- In the spring of 2009 Rhys Jones modified the pinch-wheel extruder to drive flux-less solder through a thin tube with a nichrome heater wrapped around it.
- In the spring of 2010 three students from the University of British Columbia introduced the wire-laying SpoolHead.
- In the winter of 2010-2011, Rhys Jones ran some conductivity tests on dendritic nickel.
Linear Components
- In the spring of 2011 Christopher Covington proposed graphite and resin resistors (essentially what's used in conventional resistors).
Inkjetting
Included here as it may be the most effective method of depositing semiconductor material.
Semiconductors
- In the spring of 2011 Kathleen Meehan proposed using II-IV semiconductors.
