Compared with ordinary circuit boards, HDI circuit boards have the following differences and advantages:

1.Size and weight

HDI board: Smaller and lighter. Due to the use of high-density wiring and thinner line width line spacing, HDI boards can achieve a more compact design.

Ordinary circuit board: usually larger and heavier, suitable for simpler and low-density wiring needs.

2.Material and structure

HDI circuit board: Usually use dual panels as the core board, and then form a multi-layer structure through continuous lamination, known as “BUM” accumulation of multiple layers (circuit packaging technology). Electrical connections between layers are achieved by using many tiny blind and buried holes.

Ordinary circuit board: The traditional multi-layer structure is mainly inter-layer connection through the hole, and the blind buried hole can also be used to achieve the electrical connection between the layers, but its design and manufacturing process is relatively simple, the aperture is large, and the wiring density is low, which is suitable for low to medium density application needs.

3.Production process

HDI circuit board: The use of laser direct drilling technology, can achieve smaller aperture of blind holes and buried holes, aperture less than 150um. At the same time, the requirements for hole position precision control, cost and production efficiency are higher.

Ordinary circuit board: the main use of mechanical drilling technology, the aperture and the number of layers is usually large.

4.Wiring density

HDI circuit board: The wiring density is higher, the line width and line distance are usually not more than 76.2um, and the welding contact point density is greater than 50 per square centimeter.

Ordinary circuit board: low wiring density, wide line width and line distance, low welding contact point density.

5. dielectric layer thickness

HDI boards: The dielectric layer thickness is thinner, usually less than 80um, and the thickness uniformity is higher, especially on high-density boards and packaged substrates with characteristic impedance control

Ordinary circuit board: the dielectric layer thickness is thick, and the requirements for thickness uniformity are relatively low.

6.Electrical performance

HDI circuit board: has better electrical performance, can enhance signal strength and reliability, and has significant improvement in RF interference, electromagnetic wave interference, electrostatic discharge, thermal conductivity and so on.

Ordinary circuit board: the electrical performance is relatively low, suitable for applications with low signal transmission requirements

7.Design flexibility

Because of its high density wiring design, HDI circuit boards can realize more complex circuit designs in a limited space. This gives designers greater flexibility when designing products, and the ability to increase functionality and performance without increasing size.

Although HDI circuit boards have obvious advantages in performance and design, the manufacturing process is relatively complex, and the requirements for equipment and technology are high. The Pullin circuit uses high-level technologies such as laser drilling, precision alignment and micro-blind hole filling, which ensure the high quality of the HDI board.

Compared with ordinary circuit boards, HDI circuit boards have higher wiring density, better electrical performance and smaller size, but their manufacturing process is complex and the cost is high. The overall wiring density and electrical performance of traditional multi-layer circuit boards are not as good as HDI circuit boards, which is suitable for medium and low density applications.