Here are five common mistakes that are typically made during the PCB fabrication process and ways to avoid them.
As the demand for miniature and powerful devices keeps increasing, so does the need for multi-layer PCBs. PCBs are certainly increasing in layers as well as in component density. What is important in ensuring accuracy in such PCBs is the design and thereafter its fabrication. Despite the growing use of such PCBs, some mistakes are relatively common when it comes to the PCB fabrication process. We bring to you five common mistakes that are typically made during the fabrication process as also ways to avoid them. With due attention paid to these five aspects, you can ensure that you can avoid costly mistakes and that you do not have to deal with correcting these errors when the electronic device is ready to be sent out into the market.
Multi-Layer PCB Fabrication Process: 5 common issues and how to avoid them
1. Design Complexities
Multiple layers come with an intrinsic complexity in design. The probability of complexity is further increased on account of the demands that are placed by miniaturization.
The two risks that multilayer PCBs particularly deal with in terms of design include:
Let us look at them a little closer. A bow refers to the spherical curve while the twist is a deformation that is seen parallel to the diagonal of the board. In order to avoid bows and twists, the following measures need to be taken:
2. Selection of Substrate Material
A common mistake in fabricating multilayer PCB is the choice of the wrong substrate material. In choosing the right material, you need to ensure that the material conducts electricity as well as provides insulation between the conductive layers.
Here are the aspects to check for in making the right choice of material:
Typically, FR 4 is a popular choice when it comes to the substrate material.
3. Resin-plugged Through Manufacturing
Resin-plugging is fast emerging as a standard process when it comes to PCBs, especially where there are a large number of layers. Resin-plugging is the go-to process, especially where pressure-filling and green oil-plugging resins cannot provide optimal results. Resin plugging is a preventive measure that helps in securing vias from the unwanted flow of the solder material. However, manufacturers typically face the issue of resin plug holes. This is an issue that needs to be solved with the help of a vacuum plug machine.
4. Heat Dissipation
When it comes to the multi-layer PCB fabrication process, overheating is an issue. What is required is proper heat dissipation methods. There are a number of methods that ensure heat dissipation is facilitated. These include:
5. Back Drilling
Very often, multilayer PCB fabrication comes with issues such as loss of circulation, hole blocking, and more. Back drilling has a very important role to play as a popular PCB manufacturing technique. With the use of the right angle as well as the right manufacturing parameters, these issues can be avoided.
By avoiding the above 5 common mistakes you can ensure reliable and performance-driven Multilayer PCBs.
In addition to the above 5 mistakes, here are some design aspects to watch out for:
Last but not the least, ensure that there is robust test planning so that you do not have to deal with costs of rework and product recalls.
About the Author
Suresh Patel has worked as a sales engineer and other management roles at Mer-Mar Electronics. He brings 25 years of experience in printed circuit board sales and technical client service and managing business. You can connect with him on Twitter.