Stacked micro vias technology in HDI boards: Innovative applications for high-density interconnection

As a key interconnection component in modern electronic equipment, HDI (High density Interconnection) circuit boards achieve high density wiring and high speed signal transmission through advanced manufacturing processes. Among them, stacked micro vias technology is an important innovation technology in HDI circuit board, which plays an important role in blind hole board, arbitrary level circuit board and HDI technical circuit board.

一、What is definition and function of stacked micro vias?

Stacked micro vias to layering multiple holes on a PCB (printed circuit board) to enable electrical connections in a very limited space. The role of stack vias is mainly reflected in the following aspects:

1. Increased circuit density: By stacking vias on different layers, the PCB's circuit density can be effectively improved and more complex circuit designs can be achieved.

2. Improve electrical performance: Stacked vias can shorten the signal transmission path, reduce signal interference and loss, thereby improving the performance stability of the circuit.

3. To achieve a variety of functions: Stacked vias can be used to achieve power distribution, ground plane connection, signal differential pairs, capacitor layout and other functional requirements.

二、What is production process and technology selection of stack via?

1. Production process：

The production of stacked vias mainly includes the following steps:

- Design planning: According to the requirements of the circuit, determine the position, number and level of stacked vias.

- Hole drilling: Through laser or mechanical drilling and other methods to drill holes on different layers to form a stack structure.

- Surface treatment: The holes are surface treated to improve electrical conductivity and the connection between protective layers.

- Blocking and copper plating: a blocking agent is applied to the surface of the stack vias to prevent copper deposition in the holes during the copper plating process; Subsequently, electroplating is applied to the surface of the stacked vias to form an electrical connection.

2. Technology selection：

The production of stacked vias can use laser or mechanical drilling two technologies:

- Laser drilling: Laser drilling technology has the advantages of high precision, non-contact, and suitable for a variety of materials. It is suitable for small aperture and complex cabling dense stack via production.

- Mechanical drilling: Mechanical drilling using mechanical tools for hole drilling, suitable for large aperture and general circuit density of the stacked vias production.

三、Application of stacked vias technology in different occasions

Stacked vias technology is widely used in blind vias board, pcb any layer, and HDI technology pcb.

- Blind via in pad: In the blind vias board, the stacked vias can help realize the electrical connection between different layers, improve the circuit efficiency and signal transmission performance.

- PCB any layer: any level circuit board needs to realize complex circuit in a small space, and the stacking technology can effectively improve the functional density and performance of the circuit board.

- HDI technology PCB: HDI technology circuit board has high requirements for high-density interconnection, and vias  stacking technology can meet the needs of complex circuit and miniaturization design.

Conclusion：

As an innovative application in HDI circuit board manufacturing, vias stacking technology plays a vital role in modern electronic equipment by increasing the circuit density, improving the electrical performance and realizing a variety of functions. In the production process, you can choose laser drilling or mechanical drilling and other technologies, according to the specific requirements to choose the appropriate method. With the continuous development of technology, stacked micro vias technology will further promote the high-density interconnection of HDI circuit boards and the innovative development of electronic devices.