2-step HDI PCB is also called 2-step HDI board or 2-step HDI circuit board, is a kind of high-density PCB board produced by using micro-blind buried hole technology, the line distribution density is relatively high. Therefore, the 2nd order HDI PCB is also a kind of blind buried hole board or blind buried hole board circuit board.

2nd order HDI circuit boards are widely used in cell phones, digital (camera) cameras, MP3, MP4, notebook computers, automotive electronics and other digital products, etc., which are more widely used in the field of cell phones.