"Investigation: Resolving BOM Mishaps and Track Mark Missteps in Printed Circuit Board Manufacturing"
In the realm of electronic design and manufacturing, even the smallest oversight can lead to significant issues during the production process. A recent case study highlights several common PCB assembly errors and the solutions implemented to rectify them.
The design in question featured several components, such as the MAX-792TESE microprocessor supervisory circuit, HDSP-H211 LED display, 650922-5 board-to-board connector, BR1101W SMT LED, and 87215-4 vertical through-hole connector, which did not have direction or cathode markings in their datasheets. This omission can lead to incorrect component placement and potential functionality issues.
One of the primary challenges in this design was the use of an obsolete embedded SMT digital signal processor (DSP), ADSP21065LKS-240. To tackle this issue, the team maintained an up-to-date and validated Bill of Materials (BOM) with checks against component obsolescence databases or supplier notifications. They also implemented strict version control and change management for design files and BOMs.
Sierra Circuits, a leading manufacturer of high-quality circuit boards, played a crucial role in resolving these errors. They ensured that all PCB footprints were verified against the exact component datasheets before production. They also offered assistance to eliminate footprint and BOM errors in the design.
Another common error was the mismatch between component dimensions and footprints. To avoid this, the team optimized via placement and hole sizes to fit component leads precisely, ensuring a perfect fit and avoiding poor solder joints and mechanical instability.
Missing component orientation was another issue that was addressed by clearly marking polarity and orientation indicators on the PCB silkscreen and in design documentation. The team also trained assemblers on interpreting these markings and used automated assembly machines with verified pick-and-place data files to avoid human orientation errors.
The team also encountered missing datasheets, which were resolved by making it mandatory to attach or reference component datasheets in CAD and PLM systems used during PCB design and assembly preparation. This measure helped reduce errors due to missing or inconsistent datasheet information.
In the end, the team applied rigorous design reviews, PLM and CAD version control, clear and consistent silkscreen markings, access to up-to-date datasheets, and training operators to reduce common PCB assembly errors. These measures holistically addressed errors linked to components, data, and assembly instructions.
For components without provided datasheets, the parts' details were obtained from the vendors' datasheets. The PCB footprint, an arrangement of pads where a component is soldered on a board, defining the part clearance from drilled holes, board edges, and other components, was also verified.
Component shortages may delay board production, and the customer was asked to share alternative parts and footprints for several components. The BOM in this design was also missing MPNs for certain parts.
In conclusion, by adhering to best practices in PCB assembly error reduction, teams can ensure a smoother production process and avoid common pitfalls. For more information on PCB assembly, visit Sierra Circuits' PCB assembly page.
Technology plays a crucial role in component sourcing, as a team maintained an up-to-date and validated Bill of Materials (BOM) with checks against component obsolescence databases or supplier notifications to tackle issues with obsolete components. Component shortages, which can delay board production, were addressed by asking the customer to share alternative parts and footprints.
In this case study, the importance of technology in ensuring the accuracy of component sourcing is evident, as it enabled the team to identify and resolve issues related to obsolete components and avoid potential delays due to part shortages.
