You would think that in this day and age, PCB component placement is without issues given modern technologies used on the assembly floor. Certainly, it is without question that traditional tape and reel packaging is used to allow the pick and place machine to place components as accurately as possible on the board.
But, it is important for you to know that there are exceptions in the form of problematic areas. When these issues arise they must be dealt with before they create larger problems later in the assembly process. Problems can occur periodically largely due to the fact PCBs continue to shrink in size with considerably more complex BGA, QFP, CSP, and leadless BGA packages mounted on these boards. Therefore, it is a good idea for you, the OEM, to be more aware of these areas so that you can maintain high quality products and successful time to market.
To get greater details on what you should know about PCB component placement, look for our article in the September issue of PCD&F/Circuits Assembly Magazine.
Meanwhile, here are some tips you can follow to assure that your PCB assembly side steps certain placement issues:
- Get assurances from your contract manufacturer (CM) that it has a comprehensive checklist to verify the components to be used on your project.
- Find out how QC performs the critical feeder component check, Fig. 1.
- Assure that your CM uses first article inspection (FAI) prior to boards undergoing reflow.
- Encourage your CM to avoid using ìconsigned componentsî cut out from the tape and reel.
- Pad design is crucial to meet component sizes specified in the BOM. It is of utmost importance for the OEM to conduct both PCB design and assembly with one CM that can efficiently do both to avoid assembly issues.
- Use a CM with the latest x-ray systems that can catch critical issues on the assembly floor.
splits your boardís circuitry.Ensure the PCB designer correctly
The best of all worlds for the OEM is to have a CM with in-house design and assembly and close ties to a highly reputable fab house. With a CM like this, the OEM is assured that assembly and design teams frequently interact to resolve an assortment of placement concerns. Therefore, to have successful and accurate placement, PCB designers must closely interact with assembly and process engineers to assure the right type components are used and placed on the PCBs.