What technologies are mainly used in PCB multilayer boards?

What technologies are mainly used in PCB multilayer boards?

In the vast field of hardware engineering, the design and manufacture of multilayer Pcb Boards undoubtedly constitute a complex and intricate branch. For engineers who are new to this field, the internal structural complexity of multilayer PCB boards, especially those with up to ten or even more layers, is often breathtaking.

The manufacturing of multilayer PCB boards does not differ significantly from single-layer or double-layer boards in terms of etched circuitry; however, the true challenge lies in the fabrication process of vias. Via technology, as the core of High-Density Interconnect (HDI) boards, is achieved by drilling holes in the board and plating them with copper. This seemingly simple process has a crucial impact on the peRFormance and reliability of multilayer PCB boards.

Among the classifications of multilayer PCB boards, the common types include through-hole boards, first-order boards, second-order boards, and second-order stacked via boards. Through-hole boards are the foundation of all multilayer PCB boards, characterized by holes that penetrate all layers, whether for external or internal circuitry. This design allows current to flow freely between different layers, thereby enhancing the overall performance of the circuit board. However, as the number of layers increases, the manufacturing difficulty and cost of through-hole boards also increase accordingly.

To address this challenge, high-density boards (HDI boards) emerged. HDI boards use laser technology to drill holes in the surface layer with diameters as small as 0.1mm. These laser holes only penetrate the board material without affecting the internal copper layers, allowing for drilling on the outer surface without interfering with internal circuitry. The advent of this technology has greatly increased the wiring density and signal transmission speed of multilayer PCB boards.

Building upon HDI boards, second-order HDI boards and stacked via boards further advanced the development of multilayer PCB board technology. Second-order HDI boards feature two layers of laser holes, typically used in PCB designs with eight or more layers. This design not only increases wiring density but also enhances the connection reliability and durability of the circuit board through the "staggered via" technology, which allows for copper plating within the holes. Stacked via boards are even more complex, with two layers of laser holes overlapping in position, making the circuit layout more compact. However, this design also brings higher manufacturing costs and processing difficulties.

Any-layer interconnect boards represent the pinnacle of multilayer PCB board technology. Each layer of this type of PCB board can have laser holes, achieving extremely high design freedom. Due to their extremely high manufacturing costs, they are usually only adopted in high-end products. Nevertheless, it is this technological breakthrough that makes it possible to enhance the performance and reduce the size of electronic devices.

As the number of PCB layers increases and via technology becomes more complex, the design and manufacturing costs of PCBs also rise accordingly. Therefore, choosing the right manufacturing factory becomes particularly important. Minintel is a precision factory specializing in high-level multilayer PCB processing, with dedicated production lines and specialized processing and testing equipment for HDI processing. These advanced production equipment and technological means ensure that PCBs can be manufactured with high precision and quality.