A well-known business axiom asserts, “No job is finished until the paperwork is done.” This is certainly true for the construction of electronic circuit boards. PCB assembly is undoubtedly the final stage of manufacturing; however, your boards are not ready to ship until the package includes all necessary documentation detailing the package contents and process information. This should include a PCB assembly inspection report format that is complete and understandable.
What Is an Assembly Inspection Report?
The process of converting the design file package used to order your PCB assembly into a physical embodiment that accurately reflects your design intent follows a set of well-defined steps divided into two stages: fabrication and assembly. As assembly is the latter stage, the responsibility of ensuring that your board meets its design requirements generally falls within the assembly process. This includes performing inspections to validate the results and quality of the board build. The documentation and conclusions of these inspections are recorded in the PCB assembly inspection report.
Types of PCB Assembly Report Inspections
- Visual inspection
Visual inspections are implemented throughout the PCB assembly process and are invaluable, as some common failure modes are readily identifiable by the naked eye or with modest magnification.
- X-ray inspection
- Automated Optical Inspection (AOI)
PCB optical inspections, which are often automated, represent one of the most important inspection types performed during assembly. These inspections can detect solder joint quality problems, such as solder bridging, tombstoning, and insufficient solder relief; likewise, incorrectly oriented, bad, or counterfeit components can also be identified.
- Resistivity of Solvent Extract (ROSE) Testing
ROSE testing ensures that contaminants do not remain on the board after PCB assembly. A third-party testing facility may be required, as many CMs do not have the equipment necessary to carry out ROSE testing.
A distinction must be made between a PCB assembly inspection report, which is generally provided by CMs during the development or prototyping process, and a first article inspection report (FAIR) that is provided at or near the first run of volume production. An assembly inspection, including the types listed above, provides a quality control process to certify that all board builds during prototyping and production meet applicable standards and the developer’s specifications. In addition to quality verification, the first article inspection (FAI) denotes the process, materials, equipment and location utilized for final board production. The SAE standard, AS9102B Aerospace First Article Inspection Requirement, provides a three-page template and the basic requirements for a FAIR that satisfies aerospace industry component security protocols.
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Is There a Standard PCB Assembly Inspection Report Format?
The basic answer to this question is that there is not “an industry-standard” PCB assembly inspection report format required for all assembly inspections. That said, certain industries—for example, medical devices, automotive and aerospace—require documentation to support the quality of the board manufacturing process, including assembly. Likewise, many developers and OEMs request an assembly inspection report. In these cases, the following elements should be included:
Essential Elements for PCB Assembly Inspection Reports
- The components and subassemblies inspected
- The type of inspections and tests performed
- The inspection results that include any errors discovered and the resolution process
- Whether any changes were made to the design and why
- The equipment used for inspections
- When and where the inspections were conducted
If you require or desire that your CM provides you with a PCB assembly inspection report, you should expect the items listed above to be included, as they will present a helpful overview of the quality of the process and your built boards.
|Tempo’s Software-Driven Smart Factory Delivers the Industry’s Leading Custom Turnkey PCBA Manufacturing Services
Working with Tempo Automation, the industry leader for fast, high-quality PCBA manufacturing for prototypes and low-volume production, you can expect that your boards will be assembled to meet all pertinent industry standards. Additionally, we will work with you early in the design process to ensure that your boards reflect your design intent.
And to help you get started on the best path, we furnish information for your DFM checks and enable you to easily view and download DRC files. If you’re an Altium Designer or Cadence Allegro user, you can simply add these files to your PCB design software. For Mentor Pads or other design packages, we furnish DRC information in other CAD formats and Excel.