How-PCBs-are-Made

You may have learned how certain products are made by watching shows on TV. Well, some of you may also wonder how PCBs are designed and made. Though the concept may seem simple in principle, there are still a lot of process parameters that have to be monitored to ensure quality through every process step. The following should serve as a brief overview of the fabrication steps.

The first step of the process is a circuit design for the layout. In the past, a sketch of the circuit on paper was all that a layout technician would be able to work with to painstaking draw the layout on acetate or some other transparent medium, but CAD software has come a long way since then. Here at PCB assembly companies such as MJS Designs, our team of designers are able to use the latest of a several CAD software packages to utilize a digital record of the schematic to keep track of all traces and pads for components. The end result is a PCB design that can be used for pattering the circuit board.

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Printed circuit boards consist of layers of fiberglass with a copper cladding on one or both sides. Two-sided cladding is typical, and it allows us to make the most use of the board space. The PCB material has to be patterned in order for the next process. That is often done by applying a polymer film to the cladding that is sensitive to UV light. The circuit design which has been transferred to a transparent medium is then placed on top of the board surface. UV light is then used to expose the pattern that will then be developed out much like the time-honored process of developing film for photographs. This leaves behind a template to mask off areas that will not be etched. For two-sided PCBs, both layers are exposed and developed prior to the etch process.

The developed sides are then placed in an etch bath that removes the unwanted metal to leave behind the PCB traces. If desired, solder mask is patterned in a similar manner to keep solder mostly at the component and trace interface. Silk screening of component names is applied in a method much similar to printing T-shirts. Though these steps seem fairly simple to understand, they present their specific process variables that can bring your PCB project to a halt if you are not sure what you’re doing. The team at MJS Designs is well equipped to handle all of your PCB design needs and then fabricate your circuit boards professionally. We’re ready to take on your next task to save time, headaches, and also money.