Edge plating or PTH is an essential step in PCB manufacturing. It is specifically for the PCBs that have multiple layers in the design. PCB Designers do so by drilling holes between the stacked layers and plating them with copper. The designers further connect this electroplating on the edges with the first and the last layer of the PCB.

If the users ask for the copper plating at the traces or planes on the two layers of the PCB, the fabricators do it by electroplating and connecting the components. Interesting, right? We have felt the same. If you want to know more about the edge plating in PCBs, continue reading this guiding article specifically written for you.

The procedure of electroplating at the PCB’s edges

Edge plating in PCB is a demanding approach because it requires intricacy and efficiency. The fabricators accurately handle the printed circuit boards while manufacturing PCBs to ensure their quality and compatibility. They should ensure that the top and the bottom PCB layers are copper plated because they support the other two sandwiched PCB layers.   

So, the manufacturers also need control over their board’s manufacturing to avoid or limit the occurrence of any possible dangerous components or events. The most common error during edge plating of PCB is burr’s creation. It blocks the walls of the plated-through holes (PTH), shortening the PCB’s life and limiting its repetitive quality performance. Edge electroplating involves the shaping, preparation, material assembly, and copper electroplating on the PCBs.

Applications of the edge plated PCBs.

Various PCB industries now prefer copper edge-plated PCBs for supportive signal transmissions. Edge plated PCBs are generally more suitable for companies that require efficient plated PCBs to connect them with metal-cased devices.

Edge plating apparently seems an easily added advanced development in PCB manufacturing. However, the concerned manufacturers who deal with it require extensive training, expertise, and utensils to do the process. They should critically look after each detail that otherwise appears miniature.

Importance of copper edge plating

The edge-plating on the PCB benefits the manufacturers and users by limiting the loss of electromagnetic radiation from the PCB planes during working. Edge plating ensures improved transmission of current between the devices through PCB.

Moreover, it offers an ultimate protective layer to the PCB and a strengthened connection among various appliances. Edge plating also enables the manufacturers to do the soldering of PCB’s edge to improve the PCB’s design. It reduces the chances of short circuits by providing resistance and space between every component and protecting each from excessive generated heat. So, edge plating on the PCB is challenging but beneficial to increase the PCB’s demand.

Limitations of the copper edge plating

PCB manufacturing is challenging because the manufacturers have to take care of the spacings and details on the boards. It limits the process of edge-plating in PCB also. They have to ensure the significant gaps on the edges to place the rout tabs while plating with copper.

PCB requires the sense of a traffic signal during the transmission between different networking devices. Therefore, it is significant to leave places for adjusting the routs on the PCB for the routing process. Moreover, the PCB manufacturers have to electroplate the PCB before PTH because it dismisses the component of V-cut scoring from the board that is essential for the PCB’s edge-plating.

FAQ:

How to copper edge plating of PCB when designing PCB?

The same copper plating method as the surface circuit is used for PCB edge copper plating, that is,the copper deposition copper plating process. Since there is no standard design method in the PCB design, the PCB engineer commonly tells the PCB manufacturer by drawing + descriptions to wrap the metal around the PCB board edge.

If the PCB edges are all copper plated (copper cannot be plated at some positions due to processing factors), there is no need to draw, and you can tell the PCB manufacturer what the edges of the PCB are coated with copper. If some special areas are copper plated, it is recommended to build a separate layer (usually called edge plating) in the PCB design file to indicate which areas contain metal.

What is the difference between primary copper plating and secondary copper plating during PCB manufacturing

First of all, the primary copper plating of PCB is also called PCB full board plating, or thickened copper (PTH and then thickened after drilling), which is mainly hole copper plating.

However, the secondary copper refers to pattern copper plating. After the outer dry film is finished, only the copper on the line of PCB is thickened. The secondary copper plating is mainly to plating the base copper to the required copper thickness of PCB.

What is the result of excessive development of PCB board on copper plating?

There are two cases of excessive PCB development, including excessive circuit development and excessive solder mask development.

If excessive PCB development, there is no impact on the copper plating step, but there is an impact on the PCB.

Excessive circuit development will cause the photosensitive film to be over-washed or even fall off. When copper plating, it will also plate copper at the position where not be copper-plated, resulting in line burrs or open and short circuits;

Excessive solder development will cause the solder mask bridge to fall off, resulting in there is not enough the edge adhesion at the window opening position, but no copper plating is required after solder mask development, so it is nothing to do with copper plating.

Conclusion:

PCB manufacturing calls for a careful and qualitative procedure to ensure optimum performance for the users. Edge plating on the PCB guarantees the same by offering an inexpensive solution. The manufacturers generally use copper for electroplating the several layers of PCB to connect them and provide protection. In short, edge plating ensures heat resistance to the different PCB components to limit the on sets of the short circuit during signal carrying.