The importance of HDI circuit board blind via and its manufacturing technology

In the manufacturing process of modern high-density electronic devices, HDI (High Density Interconnect) circuit boards play an important role. Among them, blind via is a key process in HDI circuit board manufacturing, which uses laser drilling technology to achieve more circuit connections in a limited space. SeekPCB will deeply study the importance of blind via in HDI board, and discuss the blind via manufacturing technology and the influence of blind via aspect ratio.

一、What is the importance of blind via in HDI board

The development of HDI circuit boards is designed to address the needs of increasingly small and complex electronic devices. Placing more circuit connections on a limited board area became a key challenge. As an important connection mode, the blind via is particularly important because of its ability to conduct signals between the internal layers of the circuit board. Through blind vias, higher density circuit can be achieved, reducing the number of layers and size of the board, thereby improving the performance and reliability of the overall product.

二、Blind via manufacturing technology—Laser via

In the process of HDI circuit board manufacturing, the common blind via manufacturing technology is laser via. Compared with traditional mechanical drilling, laser drilling has higher accuracy and efficiency. Laser drilling uses high-energy laser beams to burn the inner layer of the circuit board to form tiny holes, so that signal transmission can be achieved between the inner and outer layers. Laser via technology is carried out in a non-contact manner, avoiding the problem of debris generated in traditional drilling and greatly reducing the risk of damage to the board.

三、What if the effect of blind via aspect ratio on HDI board
Blind via aspect ratio refers to the ratio of the length of the blind hole to the diameter. The choice of blind via aspect ratio has significant influence on the performance of HDI circuit board. A higher aspect ratio means a longer blind via, which can lead to increased losses in signal transmission and decreased signal integrity, especially in high-frequency applications. Therefore, the aspect ratio needs to be carefully considered when designing HDI PCB prototype and optimized according to actual needs. Reasonable aspect ratio selection can improve the performance of the circuit board, reduce signal loss, and achieve a more stable and reliable circuit connection.

Conclusion：
Blind via technology in HDI circuit board is the key technology to realize high density circuit connection. By using laser drilling technology, more circuit connections can be achieved in a limited space, improving the performance and reliability of electronic devices. In addition, the design and optimization of the blind via aspect ratio also plays an important role in the performance of HDI circuit boards. In the design process of HDI PCB prototype, it is necessary to consider various factors to ensure the manufacturing quality of blind holes and the best performance of circuit performance.