CONTRACT MANUFACTURING


Add cleaning processes to your design to achieve reliable PCBs


Figure 1:


Electronics circuit board planning: When designing a PCB, there are many factors an engineer must consider, including cleaning


Emily Peck, senior chemist at MicroCare, LLC explores the importance of board maintenance to maximise performance


ffective printed circuit board (PCB) design practices are critical in order to deliver a board that performs as intended. When designing a PCB, there are many factors an engineer must consider. Everything from properly orienting the components on the board to carefully routing the signal traces to determining the best flux/paste mixture. All must be planned before any prototyping or production starts. However, cleaning is a critical aspect of PCB design that is often overlooked during initial planning.


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Previously, some PCB designers didn’t think about PCB cleaning until the very end of their


46 MAY 2021 | ELECTRONICS TODAY


project. Or, at least well into the process after important decisions about coatings, solder pastes and other materials had already been finalised. This left designers with an elegantly designed PCB, but also possibly one with flux residues which could not be removed. That resulted in a poor performing PCB that was susceptible to catastrophic field failures, disruptive product recalls and costly returns. It also impacted production timelines and budgets as designers searched for a post-manufacturing cleaning fix that might work.


Recently though, more PCB designers are recognising the benefit of specifying their


cleaning choices earlier in the design process and taking a proactive approach. It is typically much easier to identify and resolve any cleaning problems prior to prototyping and production. This is especially true when manufacturing high-reliability PCBs such as in military or medical products where cleanliness is critical or validation is required.


Specify a PCB cleaning fluid As the electronics industry continues to use smaller PCBs filled with tightly packed components, they become more difficult to clean. Reductions in pitch between


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