After disposing metallic foils on either surface of a prepreg sheet of low compressibility having conducting holes filled with conductive paste, the prepreg sheet is compressed in a state of being kept at a relatively low temperature, and after that, the temperature is raised under pressure to melt and...http://www.google.com.au/patents/US7816611?utm_source=gb-gplus-sharePatent US7816611 - Circuit board
