The Definition of PCB Z-Axis Milling

PCB Z-Axis Milling is a process used in printed circuit board (PCB) fabrication where material is selectively removed from the PCB's substrate along the Z-axis, or depth. This milling technique is often employed to create cavities, cut through layers, or make precise adjustments in thickness, enabling advanced designs like embedded components or controlled impedance features. It requires high-precision machinery to avoid damaging other layers or traces and is commonly used for complex, multi-layer PCBs where traditional etching or drilling methods may not suffice.

The Design Parameters of PCB Z-Axis Milling

The internal and external contours of the board can be processed according to customer requirements. The outer corners of the contour can be made as 90° angles or rounded corners as per the customer's request. However, the internal corners of the contour must have a minimum radius equal to the milling cutter radius.

The contours and internal openings of PCBs are usually milled, following the following rules:

   1. In general, milling does not require any additional charges.

   2. Please refrain from milling the copper to ensure the durability of the circuit board and reduce the risk of injury.

   3. To prevent issues with measurements and dimensions, a line width of 0.2mm should be used to indicate the internal and external contours of the PCB. Typically, the traces are routed at the center of the lines.

The Advantages of PCB Z-Axis Milling

   1. PCB milling offers advantages for prototype production and certain specialized PCB designs, with the biggest benefit being the absence of chemicals involved in PCB fabrication.• Milling cutters can be changed according to requirements.

   2. Using CNC machines can help speed up the process of prototype production. If you already use CNC machines for drilling, they can handle both milling and cutting simultaneously, as CNC machines are highly useful for drilling, milling, and cutting operations.

   3. In some cases, PCBs produced through milling are difficult to achieve with wet etching and require subsequent manual drilling, both of which incur higher costs compared to conventional milling.

Applications of PCB Z-Axis Milling:

   1. Cut-out

   2. Milling slots

   3. Pocket milling

   4. V-scoring

   5. Separating panels

   6. Cutting heat sink cavities