Bridging During Rigid Flex PCB Assembly

Rigid PCBs have many limitations when it comes to manufacturing and assembly, especially in small spaces. That’s why innovations like flexible and rigid-flex circuit boards have become so popular. They can offer significant advantages in a variety of applications, from medical devices to IoT products and even foldable wearables. These innovations can make your product sleeker and more portable while reducing the cost and complexity of production.

Solder bridging is one of the most common problems that occur during PCB assembly. It can happen if the solder doesn’t properly adhere to the copper traces of the board, and the bridge can cause shorting between pads or pins. It is essential to understand how to prevent this problem, so that you can avoid it in your next project.

One of the best ways to prevent solder bridging is to use a printed circuit board manufacturer that prioritizes quality work. This will ensure that your product is made correctly and that there are fewer errors during the assembly process. A contract manufacturer will be able to walk you through their production processes, and they should also have a rigorous inspection process to ensure that the work is high-quality.

Another way to avoid solder bridging is to use the right solder paste stencil. A good stencil should have a device pitch of 0.5 mm or less, and the holes should be large enough to accommodate the leads of the components. Using the correct stencil size and cleaning it thoroughly after use can help to reduce solder bridges.

Solder Bridging During Rigid Flex PCB Assembly

It is also important to follow the recommended temperature profiles and dwell times for the reflow process. This will ensure that the solder paste is melted and flows smoothly, and it will allow the component leads and PCB pads to be adequately wetted. Additionally, utilizing the right lead lengths for through-hole components will prevent solder bridges, as long leads can decrease the gap between conductors.

Finally, ensuring that the PCB solder mask is applied correctly is another important preventive measure. Solder inherently doesn’t stick to the solder mask, and not applying the solder mask to critical areas can create a high risk of solder bridges. Incorrectly placing fiducial marks on the board can also increase the likelihood of misplaced parts, which can lead to solder bridges.

If you do encounter a solder bridge, it’s easy to fix. Simply apply some desoldering wick to the area, and use your soldering iron to heat it carefully. The excess solder will flow into the wick, and you can clean up the area quickly.

If you are working on a new electronic device that needs to be slim, light, and compact, then you should consider using a flex or rigid flex pcb. These types of circuit boards can be designed in three dimensions, which means they can bend and flex for an optimal fit in your final product. This can save space and weight, as well as improve thermal stability, reliability, and assembly time.