PCB News - What is the difference between HDI board and ordinary pcb

What is the difference between HDI board and ordinary PCB

What is the difference between HDI board and ordinary PCB
HDI boards are widely used in server HDI cards, mobile phones, multi-function POS machines, and HDI security cameras. What kind of circuit board is HDI board? What is the difference between it and ordinary PCB? Let the editor answer for you one by one.

1. What is an HDI board?

HDI board (High Density Interconnector), that is, high-density interconnection board, is a circuit board with a relatively high line distribution density using micro-blind and buried via technology. The HDI board has an inner layer circuit and an outer layer circuit, and then uses processes such as drilling and metallization in the hole to realize the internal connection of each layer of the circuit.

Second, the difference between HDI board and ordinary PCB

HDI boards are generally manufactured by a layer-by-layer method, and the more the number of layers, the higher the technical grade of the plate. Ordinary HDI boards are basically one-time build-up. High-end HDI uses two-time or more build-up technology. At the same time, advanced PCB technologies such as stacking holes, electroplating and filling holes, and laser direct drilling are used. 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 electrical performance and signal accuracy of HDI boards are higher than traditional PCBs. In addition, HDI boards have better improvements to radio frequency interference, electromagnetic wave interference, electrostatic discharge, and heat conduction. High-density integration (HDI) technology can make terminal product designs more compact, while meeting higher standards of electronic performance and efficiency.

HDI board uses blind hole electroplating and then performs secondary pressing, divided into first-order, second-order, third-order, fourth-order, fifth-order, etc. The first-order is relatively simple, and the process and craftsmanship are well controlled. The main problems of the second order, one is the problem of alignment, 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 in the middle layer through a wire, which is equivalent to two first-order HDIs. The second is that the two first-order holes overlap, and the second-order is realized by superimposing. The processing is similar to two first-order holes, but there are many process points to be specially controlled, which is mentioned above. The third is to punch directly from the outer layer to the third layer (or N-2 layer). The process is different from the previous one, and the difficulty of punching is also greater. For the third-order analogy, it is the second-order analogy.

In PCB proofing, HDI is expensive, so ordinary PCB proofing manufacturers are reluctant to do it.