In the manufacturing process of PCBs (Printed Circuit Boards), the hole copper thickness refers to the thickness of a layer of copper covering the inner wall of a drilled hole. This layer of copper is deposited through an electroplating process, primarily to ensure the reliability of electrical connections and mechanical strength. The following sections provide a detailed introduction from several main aspects.

Definition and Standards of Hole Copper Thickness

  1. Definition: Hole copper thickness refers to the thickness of the copper layer formed on the inner wall of a PCB hole through the electroplating process. It is usually measured in micrometers (μm).

  2. Standards: According to the IPC-6012 standard, the minimum requirement for hole copper thickness is typically 20 micrometers (0.8 mils). This standard ensures the stability of electrical connections and mechanical strength.

  3. Measurement Methods: The hole copper thickness is usually inspected through microscopic observation or cross-section analysis to ensure it meets design and quality specifications.

PCBWay offers several options for hole copper thickness for customers to choose from: 20μm, 25μm, 30μm, 35μm, 50μm, 55μm, and 70μm.

Consequences of Insufficient Hole Copper Thickness

  1. Electrical Connection Issues: Insufficient hole copper thickness can lead to unreliable electrical connections, potentially causing circuit breaks or instability, thus affecting the normal operation of the PCB.

  2. Inadequate Mechanical Strength: The thickness of the hole copper layer is directly related to the mechanical strength of the PCB holes. If the thickness is insufficient, the hole walls can be easily damaged during installation and use, leading to the failure of the entire PCB.

  3. Poor Thermal Stability: Thinner hole copper layers are prone to thermal expansion and contraction in high-temperature environments, resulting in cracks or detachment at the connections, thereby impacting the overall performance of the circuit.

Methods for Controlling and Optimizing Hole Copper Thickness

  1. Electroplating Process Control: By optimizing electroplating process parameters, such as current density, time, and temperature, the hole copper thickness can be ensured to meet design requirements.

  2. Quality Inspection: Regular sampling inspection of PCBs during production can ensure that the hole copper thickness of each batch is within the standard range.

  3. Material Selection: Using high-quality electroplating materials and additives can improve the uniformity and adhesion of the copper layer during electroplating, thereby ensuring the stability of hole copper thickness.