Common Errors in the PCB Assembly Process

Pcb fabrication

In most cases, the circuit board assembly process is simple, quick, and convenient. Circuit board assembly also generally occurs rapidly and error free. However, sometimes problems do occur during the circuit board assembly process. Depending on the type of error, the entire legend may need to be reprinted or that step in the process may need to be repeated. The following are some of the most common errors during the turnkey PCB process.

Improper number of layer designs

More complex of circuit board assembly projects has a greater number of layers. Sometimes this error happens during the design process, meaning there were not enough layers accounted for. The problem can also occur during the printing process, when one legend does not register and an entire layer is missed. The most common multilayer boards are 4 layers, 6 layers, 8 layers, and 10 layers. However, the total number of layers that can be manufactured can exceed over 42 layers. These types of boards are used in extremely complex electronic circuits. It is also usually the higher layered circuit board assembly projects that you see these types of errors with.

Poor temperature control

Think of turnkey PCB assembly as computer or electronic manufacturing. If your computer or mobile device is exposed to extremely high of temperatures, it is likely to malfunction. If it is left out in the cold and in freezing temperatures, it may never work properly again. The same is true of the circuit board assembly process. Temperature control is very important in the design and printing process. If problems occur with the temperature controls, the PCB may not work properly. Heat can destroy components and freezing temperatures can cause important parts to not work.

Improper materials used in the printing process

There are a variety of ways to print a legend. Older materials have been upgraded, but are still used in some types of projects. Low volume PCB assembly often uses different materials than in a higher volume project. Additionally, the use of PCB design software has also changed the type of materials used in the manufacturing process. Before PCB design software was introduced, printed circuit boards were designed using clear Mylar sheets, up to four times bigger than the circuit board itself, on which designers would create a transparent photomask of the proposed design. Not using the right type of materials for the software used can cause errors in the process.

Improper spacing measurements

There are a lot of calculations in the successful creation of a printed circuit board. It is important to measure these spaces and devices multiple times for complete accuracy. Small batch PCBs will differ from larger and quick turn processes. Board designers use computer aided design systems with special software to layout the circuit pattern on the board. The spaces between electrical conducting paths are usually 0.04 inches (1.0 mm) or smaller. Because they are so small, there is very little room available for error. A minor error in measurement can cause the entire specs to be off, and thus, cause errors with the final electronic product.

Inexperience and lack of knowledge

A successful circuit board assembly project, regardless of its size or number of layers, requires experience and knowledge of the assembly process. Do not be tempted to go with a PCB manufacturing company that does not know what they are doing, simply to save a couple of dollars. Even the smallest of errors can result in an entirely wasted PCB design. Additionally, errors can make it entirely impossible to later replicate the successful printed legend.

The circuit board assembly process is very complex and detailed. If you do not know what you are doing, you could easily make a mistake that would ruin the entire PCB design. Errors can occur at any point of the design or manufacturing process, including the sizing, printing, or designing. You can also reduce the number of errors that occur by going with an experienced and knowledgeable PCB printing service.

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