I made a short literary overview about the current circuit substrates, I summarized it's components. I also explained the problems of the end of life cycle and the processing of the waste electrical equipments, especially the waste printed wiring board's (PWBs) environmental impact. I subsumed the current and previous methods of processing waste FR-4 substrates, including the waste burning, the pyrolysis, the classical method, and the supercritical CO2 method.
I went through the environmental standards, regulations, and recommandations, considering the PWB construction and waste PWB processing. I summarized them, and made my own complex recommandation, considering as much condition as possible.
I introduced the mostly used methodes of highly accelerated tests and thermoanalysis. I made highly accelerated stress tests, and water-absorption measures with polylactid acid (PLA) and cellulose acetate (CLA) substrates. I evaluated and summarized the results, and I estimated the amount of energy needed to these subtrates to degradate.
I made a comperable processing model between the withdrawal of the FR-4 and biodegradable substrates. Using the model, I specified the environmental impact of these substrates.