HDI board (High Density Interconnector) is a kind of circuit board with a relatively high line distribution density by using micro-blind and buried via technology. High-density interconnection PCB boards have inner and outer layers, and then use drilling, metalization in the hole and other processes to realize the internal connection of each layer.
High density interconnection PCB boards are generally manufactured by using a build-up method. The more build-up times, the higher the technical level of the board. Ordinary high-density printed circuit boards are basically one-time build-up. High-end HDI uses two or more build-up techniques, while using advanced PCB technologies such as stacking holes, electroplating and filling holes, and laser direct drilling.
When the density of the PCB increases beyond the eight-layer board, it is manufactured with HDI, and its cost will be lower than that of the traditional and complex pressing process. The use of advanced packaging technology for high-density interconnect PCB boards makes their electrical performance and signal accuracy higher than traditional PCBs. In addition, HDI boards have better improvements in radio frequency interference, electromagnetic wave interference, electrostatic discharge, and heat conduction.
Electronic products continue to develop towards high density and high precision. The so-called "high", in addition to improving machine performance, also reduces the size of the machine. High-density integration (HDI) technology can make terminal product designs more compact, while meeting higher standards of electronic performance and efficiency. At present, most popular electronic products, such as mobile phones, digital (camcorder) cameras, notebook computers, automotive electronics, etc., use HDI boards. With the upgrading of electronic products and market demand, the development of HDI boards will be very rapid.
The first-order high density PCB is relatively simple, and its production process and technology are well controlled.
The second-order high-density interconnection PCB board is a little troublesome. One is the alignment problem during production, and the other is the problem of punching and copper plating. There are many types of second-order designs. One is that the positions of each step are staggered. When connecting the next adjacent layer, it is connected through a wire in the middle layer, which is equivalent to two first-order HDI. The second is that two first-order holes overlap, and the second-order is realized by superimposing. The processing is also similar to two first-order holes, but there are many process points to be specially controlled. The third type is to punch directly from the outer layer to the third layer (or N-2 layer), which is different from the previous one. And the punching is also more difficult.
For the production of third-order high-density interconnect PCB boards, it is the same with the second-order analogy.