PCB News - How to understand the difference between hdi board and ordinary pcb

How to understand the difference between hdi board and ordinary PCB

hdi board introduction
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.

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 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 circuit board, it is manufactured with HDI, and its cost will be lower than that of the traditional and complex pressing process. HDI board is conducive to the use of advanced packaging technology, and its electrical performance and signal accuracy are 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 toward high density and high precision. The so-called "high", in addition to improving the performance of the machine, 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.

Ordinary PCB introduction
PCB (Printed Circuit Board), the Chinese name is printed circuit board, also known as printed circuit board, is an important electronic component, a support for electronic components, and a carrier for electrical connection of electronic components. Because it is made by electronic printing, it is called a "printed" circuit board.

Its main function is that after electronic equipment adopts printed boards, due to the consistency of similar printed boards, manual wiring errors can be avoided, and electronic components can be automatically inserted or mounted, automatic soldering, automatic detection, and guarantee Improve the quality of electronic equipment, improve labor productivity, reduce costs, and facilitate maintenance.

Are PCB boards with blind and buried vias called hdi boards?

HDI boards are high-density interconnected circuit boards. The boards that are plated with blind holes and then laminated are all HDI boards, which are divided into first-order, second-order, third-order, fourth-order, and fifth-order HDI. For example, the motherboard of iPhone 6 is fifth-order HDI.

Simply buried vias are not necessarily HDI.

How to distinguish HDI PCB first-order, second-order and third-order

The first-order is relatively simple, and the process and craftsmanship are well controlled.

The second order started to be troublesome, one was the alignment problem, and the other was the problem of punching and copper plating. There are many 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 two first-order holes are overlapped, and the second-order is realized by superposition. The processing is similar to two first-orders, 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.

The difference between hdi board and ordinary PCB

Ordinary PCB board is mainly FR-4, which is laminated with epoxy resin and electronic grade glass cloth. Generally, traditional HDI uses backed copper foil on the outer surface. Because laser drilling cannot penetrate the glass cloth, glass fiber-free backed copper foil is generally used. However, the current high-energy laser drilling machine can penetrate 1180 glass cloth. . This is no different from ordinary materials.