This is a 4 layer circuit board for IC test. HDI boards, one of the fastest growing technologies in PCBs, are now available at Pandawill. HDI Boards contain blind and/or buried vias and often contain microvias of .006 or less in diameter. They have a higher circuitry density than traditional circuit boards.
There are 6 different types of HDI boards, through vias from surface to surface, with buried vias and through vias, two or more HDI layer with through vias, passive substrate with no electrical connection, coreless construction using layer pairs and alternate constructions of coreless constructions using layer pairs.