PCB News - New Challenges in HDI Printed Circuit Board Production

With the development of products such as smart phones, tablet computers and wearable devices in the direction of miniaturization and multi-functionality, the technology of high-density interconnection printed circuit boards has been continuously improved. The distance, as well as the thickness of the conductor layer and the insulating layer are constantly decreasing, so that the number of layers of the PCB can be increased to accommodate more components without increasing the size, weight, and volume of the PCB. In addition, with the increase of wireless data transmission bandwidth and processing speed, the electrical performance of the PCB becomes extremely important.

Just as the integrated circuit industry has encountered obstacles for performance expansion and compliance with Moore's Law, the PCB industry is also facing challenges in process capability and material performance in order to continuously improve interconnect density and electrical performance. Even if the PCB adopts any-layer interconnection high-density (ALV HDI) design, there are still limitations in performance expansion and improvement, the manufacturing cost is also increased, and there is a cost-effective problem.

The PCB industry is facing the challenge of increasing the number of layers and decreasing thickness. The thickness of the insulating layer has fallen below the critical value of 50 µm, and the dimensional stability and electrical performance of the PCB (especially signal impedance and insulation resistance) have declined. At the same time, the density of signal traces continues to increase, and the width of the trace is less than 40 µm. It is very difficult to make such a trace using the traditional subtractive method. Although the additive method technology can realize the production of more refined circuits, it has the problems of high cost and small production scale.

The landing of 5G is an important national policy in 2019, which will drive the entire upstream and downstream industrial chain; 5G technology will promote the fission-type development of related fields such as the Internet of Things, cloud computing, big data and AI, and empower vertical industries and deep integration. The formation of a 5G ecosystem will inject strong impetus into the improvement of national competitiveness, social transformation and industry upgrading.

5G is gradually coming to us from concepts and experimental products. Are we ready to join hands to create a beautiful 5G era, to accept many of our worries and challenges, and to create a bright future in which everyone is happy.

Due to the advantages of low cost and easy maintenance of the carbon series direct electroplating system, electronics manufacturers choose it to replace the electroless copper process. Today, there are hundreds of high-volume carbon series direct electroplating production lines around the world. These systems are popular because they reduce water consumption, reduce wastewater generation, reduce equipment footprint and reduce energy consumption. In addition, these systems do not require noble metals such as palladium to activate, which can significantly save operating costs.

In the latest generation of smart phone technology, high-density interconnect (HDI) technology is developing towards finer line width and line spacing, which requires the use of ultra-thin copper foil as the starting point of the entire production process. This ultra-thin copper foil technology requires precise control of etching accuracy during the formation of copper interconnects. Direct electroplating processes (such as the latest generation of black hole technology) have begun advanced semi-additive production on 3 micron copper foil.