![]() However, it may impact your board’s operational lifetime. This step is sometimes omitted and does not impact board fabrication. This step is primarily to provide protection for copper areas of the board. Silkscreen errors will not prevent your board from being fabricated however, it can hamper the assembly process and may negatively affect operation. This includes pin 1 indication for integrated chips (ICs), reference numbers for components, logos, etc. The silkscreen provides reference information. This covering guards against contaminants and prevents assembly problems like solder bridging that can lead to shorts and damage. Solder mask is the covering (usually green) used everywhere on the surface except over traces and pads that protects the board. A major problem here is outgassing that can happen during assembly. Another consideration is tenting, where holes are covered instead of left open. Hole annular ring clearance can be an issue here. The conductive material for plated through holes (PTHs) and other vias is performed here. In addition to spacing and clearances between pads and traces, there is also board edge clearance to contend with. PCB FABRICATORS FULLOuter layers typically have full copper coverage and etching is used to remove the excess and expose traces and pads. Additionally, aspect-ratio is important as it determines what type of drilling can be used. These can be plated through holes (PTHs), non-plated through holes, or vias, like buried, blind or through-hole.Īlignment is an issue as well, but there are spacing and clearance issues that can impact solder masking. Traces without adequate spacing may prevent solder masking or if left uncorrected cause shorts.ĭuring this step, the board layers are aligned and pressed.Īlignment is a major issue here, as well. For example, unconnected traces will prevent signal flow which in turn halts fabrication until corrected. That are many trace issues that can occur if etching is done improperly. ![]() Unwanted copper is removed and desired copper area is left only on traces and pads. Image misalignment can cause problems for drilling vias and mounting holes. Here the images for the outer and inner layers are created on the board. Below, the main steps in the fabrication process are listed along with some of the issues that may arise and threaten your board’s manufacturability or quality. For example, for each component to be mounted during assembly, the footprint for the pads etched on the board during fabrication, must exactly match the component package type acquired. The entire process can be broken into three distinct stages: fabrication, component procurement, and assembly.Īlthough these three stages are distinct, they are interrelated and many design choices and decisions impact all of the three. The PCB Fabrication ProcessĪlthough a contract manufacturer (CM) is most often engaged to construct your boards, an understanding of the PCB manufacturing steps can provide enlightenment and an understanding of the constraints within which your CM must work. This will provide insight that can then be used to inform a strategy to design for ease of PCB fabrication and support the creation of a quality product. Both of these are important however, assembly cannot be done until successful fabrication is achieved and the choices you make during layout are directly proportional to how well your board is built and how much it will cost.įirst, let’s take a look at fabrication in depth. For PCBs, there are two parts to the manufacturing process: fabrication, during which the physical architecture or PCB layout is constructed, and assembly, where the components are mounted on the board. Usability is one of the primary criteria by which your design is judged and manufacturability determines its quality, ability to perform its function reliably, or if it can be built at all. Although, I learned virtually everything about working on cars from him I also learned something that was even more valuable to me in my career as a designer of electrical circuits: the difference between good and bad designs.Ī good design is when the designer incorporates who will be using the product and how it will be built into the process. ![]() Eventually, he became a great mechanic and some say the best automobile body repairman in the area. After being thrust into the role of provider for a large family at an early age, he dropped out of school to learn a trade that would provide adequate income to support his family. However, he had a capacity that many do not possess to teach himself. My father-in-law was not a learned man, at least with respect to formal education. ![]()
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