Special PCB, in fact, can also be classified to Metal Core PCB or FR4 PCB, if we sorted PCB by board material. Considering the specialrequirements of these different boards, such as High Frequency, 10 oz heavy copper, buried & blind unique, we name it as "Special PCB".
Right now, we can make various special printed circuit boards, but not limited to:
High frequency RF boards: RF board us Rogers, Taconic or other high frequency materials and normally, the frequency is between 300MHz ~ 3GHz, or much bigger;
High Tg PCB: Tg value of board material is 170~210 Degree. Tg value of normal FR4 board is about 130~150 Degree.
Heavy Copper PCB: copper weight is 4~10 OZ/ft2, and 20~200 OZ/ft2 refers to extreme heavy copper printed circuit board;
Ceramic PCB: has excellent high pressure, high insulation, high frequency, high temperature, and high reliable and minor volume electronic;
HDI PCB: with buried & blind via, drill layer up like: 1-2-1, or 2-4-2, need laser drilling, and PTH <=0.1mm;
Beside from above requirements of PCB, we can also make other special boards, such as :