HDI board is the abbreviation of High Density Inverter. It is a kind of (technology) for producing printed circuit boards. It is a circuit board with relatively high line distribution density using micro blind buried hole technology. HDI board is a compact product designed for small-capacity users. It adopts modular parallel design. One module has a capacity of 1000VA (height 1U), natural cooling, and can be directly placed in a 19″ rack. Up to 6 modules can be connected in parallel. This product adopts full digital signal process control (DSP) technology and multiple patented technologies. It has full range of load adaptability and strong short-term overload capacity, and can ignore the load power factor and peak factor.

In fact, there is no clear definition of HDI high-density manufacturing method, but generally there is a big difference between HDI and non-HDI. First of all, the aperture used in the circuit carrier made of HDI must be less than or equal to 6mil (1/1,000 inch), and the ring diameter of the hole ring must be ≦10mil, and the layout density of the line contacts must be greater than 130 points per square inch, and the line spacing of the signal line must be less than 3mil.