PCB manufacturing is a complex process that involves the assembly of circuit boards and their components. High quality PCB fabrication and assembly are essential for the overall reliability of the finished product. With increasing complexity of PCB designs, lack of proper planning can lead to high failure rates. In this article, we’ll discuss the most common PCB manufacturing defects. These defects are caused by a lack of planning, faulty components, and poor quality parts.
Solder bridging
During the PCB manufacturing process, a solder mask is used to prevent solder bridges. This layer helps keep the solder applied to pads. The mask can be a different color for aesthetic or manufacturing reasons, but it works to prevent solder bridges. Solder bridges are a common pcb manufacturing defect. Solder bridges can be fixed by removing excess solder with a hot iron or a solder sucker or wick.
When designing a PCB, it is important to remember that large surface pads and holes can result in solder bridges. Pads with annular rings reduce the distance between adjacent pins and are more susceptible to solder bridges. To minimize the risk of bridge soldering, use datasheets to properly size the surface and through-hole pad. A common approach is to design for producibility. This means making sure that the PCB can be produced by a CM or contract manufacturer.
Lack of space
Insufficient space in a PCB assembly process can be a major cause of failure, especially in more complex products. Not only is there not enough space to accommodate the components, it can also make rework difficult and delay assembly. Additionally, lack of space can lead to the improper placement of connectors, human interfaces, or other components. These defects can cause the product to fail prematurely.
Moreover, components with inadequate space on the PCB may be overheated or even burn. This may affect adjacent components. To prevent this, over-stuffing the PCB can be a good option. This technique can save money and speed up production. It also avoids costly mistakes later. One of the most important aspects of PCB manufacturing is the design phase. By paying attention to the dimensions of components, the team will be able to avoid a faulty board.
Wire breaks
A PCB has many common defects, including wire breaks. To prevent these defects, PCB manufacturers should follow strict manufacturing practices and keep the right humidity and temperature levels. They should also use tough flux to minimize movement during un-reflowed assembly and solder the boards properly. However, wire breaks are a real problem for manufacturers because they can cause the PCB to fail during operation. A thorough inspection of the PCB can save your product from a useless failure.
Component shift
Common PCB manufacturing defects include component shift, and it can be difficult to detect the culprits. Component shift is an issue that can arise for a number of reasons, including the mismatch of component pads and pad geometry, bent leads, and asymmetrical component heat sinking. PCB manufacturers can minimize the chances of component shift by following reflow profiles and improving component accuracy in SMT pick and place machines. Tough flux can also help increase PCB solderability and reduce component movement.
Component shift is a common PCB defect caused by improper alignment of PCB parts during the soldering process. It can result in open joints, shorts, and crossed signal lines. Components can shift due to many reasons, including the incorrect solder temperature, vibration caused by conveyor systems, and lopsided heat sinks. If you’re a manufacturer of PCBs, consider these common PCB manufacturing defects:
