The external elements such as humidity, pressure and temperature can cause damage to a printed circuit board. The human skin is not an exception to that.
The skin is a conductor that one can experience an electric shock if one accidentally touches the PCB with flowing electrical current on its pathways. It is therefore important to avoid skin contact with the board as much as possible, and if inevitable, one should hold it by its edges. Also the eyes and nose are exposed to chemicals’ fumes during the etching process, so goggles and masks should be worn while doing PCB work or project.
It is not only those who are working on PCB that deserve protection, but also the printed circuit board. A minor defect that escapes ocular inspection and electrical testing can cause PCB deterioration and failure. PCBs can be prone to conductive anodic filament formation. These CAFs can form from visa and laminate cracks that reckless plating and drilling can cause. CAFs, described as copper salt growths, can cause short circuits.
A carefully examined PCB design is necessary to ensure proper spacing and placement of electrical components and to serve as a guide in precise drilling. The resin and glass separation can occur if moisture passes through the glass fibers. The higher temperatures that lead-free soldering requires can be damaging to the substrate, so manufacturers should choose the proper substrate material for an application or product. The glass transition temperature must be considered, too, as when the substrate melts at very high temperatures, it can absorb the contaminants that can cause corrosion of laminates or metals. Delamination can decrease the thermal conductivity of the substrates, making a board failure.
If the PCB’s substrate measurement does not seemingly cover all of the electrical components, the design needs to be modified and improved. The manufacturer may consider a multi-layered PCB instead of the single-layered for a complicated circuitry or an effective power distribution. The more the layers there are, the more costly the PCB is.
The thicker the copper layer is, the more current can flow to it and the higher its thermal conductivity. Double-sided or multiple-layered bare boards are the choice for surface mount technology. But to create visa, manufacturers often use the through-hole technology, too.
Visa are electrical connections between layers. They should be properly coated so that there would be no leaking of ions or corrosion of the copper underneath.
Electro migration, which is the transport of metal ions to unintended pathways, can be a result of improper chemical etching or immersion metal processes. Metals that are embedded on to the copper can cause an unwanted reaction if they are exposed to environmental chemicals or conditions. The mechanical and chemical stress on the board can affect its quality. The metal traces and glass substrate can crack under mechanical stress.
Electrical overstress, characterized as a thermal damage, can occur in poorly designed circuit boards. It can cause high voltage to flow even in insulators, resulting to PCB overheating. High electrical currents that flow to components, especially to ICs, can disrupt with their normal functions. They eventually lose function in repeated or lasting exposure to high voltage.
In addition to proper techniques and processes in PCB fabrication and assembly, its storage matters, too. Keeping the unused bare board in the package can help prevent damage from moisture, which is the primary concern in the substrate’s integrity or intactness. Baking the printed circuit board, which is timely and costly, can be necessary to ensure that no moisture is retained. However, if the temperature is too high, the metals can degrade or they can react with other metals.
There are other storage methods that manufacturers should apply. They can use a desiccant that induces dryness within the moisture-resistant packaging. It should be with no sulfur.
Proper handling, storage, and testing of the printed circuit board should be compliant with PCB manufacturing guidelines. These can ensure that it is of quality.
PCB design is necessary to ensure proper spacing and placement of electrical component and to serve as a guide in precise drilling.