The Impact of a Printed Circuit Board Copper Surface Protection Layer over Lead-Free Solder Joints
The technology industry is ever-evolving, most significantly on the component level. One of the most recent advancements is the shift from lead-containing solders to lead-free ones. While traditionally lead-based solders have been the backbone of component soldering, their toxic nature is rapidly being pushed to the wayside. As a result, in countless electronic systems and devices across the globe, lead-free solders are gaining in use. This leads to a question of how to best protect these lead-free solder joints against harsh environmental elements common in the technology market. In this report, the impact of adding a printed circuit board (PCB) copper surface protection layer to solder joints made with lead-free solders in considered.
Lead-free solders are far superior to traditional lead-based ones. In addition to producing a much more safe and reliable connection, they also hold up better in hostile environmental conditions. These new formulas consist primarily of tin and silver, which are harder and have higher melting points than lead-based alloys. This is beneficial to the consumer, who is increasingly dependent upon technology with more and more sophisticated circuits, as it adds extra protection to their circuit board components.
The primary benefit of a PCB copper surface protection layer is its ability to effectively block thermal shock. Thermal shock is the expanding and contracting of the copper layer on the printed circuit board caused by rapid and drastic changes in temperature. In this process, gaps and moisture can be created in the region of solder joints, compromising the entire connection. The copper layer helps prevent these temperature fluctuations, providing added protection to the lead-free solder connections.
In addition to thermal shock, a copper layer helps keep the PCB environment clean. This is of utmost importance to ensure optimal lead-free solder connections. In the event that any foreign substances or contaminants are present within these solder layers, the corrosion resistance may be compromised, leading to a lower lifetime or failed circuit boards.
Furthermore, a solder mask or insulated layer of substrate material helps ensure the integrity and usability of the printed circuit board. The solder mask is primarily a layer of insulating material that resists corrosion, preventing solder broaching as a result of aggressive movements during normal operation. In this way, the solder mask helps provide additional protection for the lead-free solder connections.
Overall, adding a copper layer to a printed circuit board containing lead-free solder is beneficial for several reasons. It acts as a barrier to thermal shock and other contaminants, helping to maintain the integrity of the board under hostile usage conditions. Additionally, a solder mask gives further resistance against corrosion and broaching, thus furthering the useful life of a printed circuit board.
For all these reasons, the impact of adding a printed circuit board copper surface protection layer to lead-free solder joints is significant. The added layer increases the longevity of the connection, while protecting it from environmental elements that could be damaging. Of course, it is important to ensure that whatever materials are used are compatible and meet a manufacturer’s specifications. However, when properly constructed, a board with a copper layer will offer superior reliability and performance compared to one without one.
