PCB substrate delamination of a printed circuit board occurs when the layers of the board separate or peel apart from each other. This can be a significant issue in electronic manufacturing and can result from various factors, including:

  1. Moisture Ingress: One of the most common causes of PCB delamination is moisture entering the board. Water can infiltrate the PCB through various means, such as improper storage, exposure to high humidity, or inadequate sealing during manufacturing. Over time, moisture can weaken the bond between layers and cause them to separate.
  2. Thermal Stress: PCBs are exposed to temperature fluctuations during their lifecycle. Rapid heating or cooling, especially during soldering processes, can lead to thermal stress. If the PCB materials have different coefficients of thermal expansion (CTE), it can cause the layers to expand and contract at different rates, leading to delamination over time. This is why some critical PCB applications undergo thermal cycling testing to prevent possible PCB substrate delamination.
  3. Poor Adhesive Quality: Delamination can occur if the adhesive used to bond the layers of the PCB is of low quality or not applied correctly during the manufacturing process. If the adhesive doesn’t provide a robust and reliable bond, it can lead to separation over time.
  4. Chemical Exposure: Exposure to harsh chemicals or solvents can weaken the bonding materials in a PCB and cause delamination. This can happen during cleaning processes or if the PCB comes into contact with corrosive substances.
  5. Mechanical Stress: Mechanical stress, such as excessive bending, flexing, or physical impact, can lead to delamination. PCBs are designed to withstand a certain amount of stress, but exceeding their mechanical limits can result in layer separation.
  6. Manufacturing Defects: Delamination can also occur due to manufacturing defects, such as improper lamination processes, inadequate curing of adhesive materials, or contamination during assembly.
  7. Age and Wear: PCBs can experience wear and tear over time, especially in high-stress applications or environments. Aging can weaken the materials and adhesives, making delamination more likely.

PCB substrate delamination prevention requires following proper PCB manufacturing and handling practices. This includes using high-quality materials, maintaining controlled environmental conditions, and ensuring the PCB design considers factors like thermal expansion and mechanical stress. Additionally, adhering to industry standards and quality control processes can help reduce the risk of delamination in PCBs.