Before a PCB board is put into production and ready for assembly, you must generate a set of documents to assist your manufacturer. These are your PCB design output files, also known as manufacturing files, manufacturing data, assembly files, etc. Manufacturers and assemblers will use different sets of output files to produce your PCBA, and the design team must generate these files before the product is quoted and put into manufacturing. Before emailing the design file to the manufacturer, be sure to get a list of the manufacturing and assembly documents it needs. If you are a novice designer, take the time to read the basic PCB manufacturing file extensions below.
List of PCB design output files A list of common PCB manufacturing files is shown below. You may not need to generate everything in this list for every manufacturer, but it's best to create them all so that you can ensure that your device can be produced almost anywhere.
Manufacturing files - File formats used to create templates for bare board production, including Gerber RS-274-X/X2, IPC-2581, and ODB++. The NC drilling file is used to program the CNC drilling machine to place the drilling holes on the bare board.
Assembly file - The two main files required for assembly are the Bill of Materials (BOM) and the pickup file. Both are used to match parts and arrangements during assembly. The solder layer file for assembly will be generated along with your manufacturing file.
Printouts and drawings - Manufacturing and assembly drawings are like your design blueprints and contain a lot of information. Typically, you would put this information in your quotation, but creating a manufacturing diagram helps ensure that manufacturers anywhere understand exactly how you want the board to be produced.
STEP file and 3D printing - Together, these two sets of files allow the assembler to clearly see the direction of certain components in non-standard packages.
Test point Report - This file includes a set of nodes designated for electrical measurement and can be used for continuity testing or more specific in-circuit testing.
Miscellaneous documentation - Some manufacturers may request some miscellaneous documentation. These may include schematics, netlists, mechanical lamination files (such as Gerber files), or other reports with comments and backdrilling requirements.
Binaries and test documentation - In high volume manufacturing, some products may require online flash memory of binaries and subsequent functional testing to ensure that every product manufactured is fully functional. These requirements need to be specified, and test fixtures may need to be provided to help with automated functional testing.
Start with Manufacturing Documents and documentation Before your design goes into manufacturing and assembly, manufacturing documents must be sent to the DFM for review and quotation. The manufacturer will check these documents to ensure that the design is within its capabilities. This will be done with more specialized CAM software that will check the manufacturing documentation for gaps, feature dimensions, feature spacing, and any other aspects of the physical design that may present manufacturing challenges. Gerber files are most commonly used for this stage of the process, but any manufacturer should be able to use other standard manufacturing file formats (ODB++ or IPC-2581).
The manufacturer will check your manufacturing documentation, especially the copper and mask pattern in each layer, to ensure that the board can be manufactured reliably. Manufacturing notes are also important because they provide all the other information used to manufacture a bare PCB. Things like conformal coating, surface finish, specific material to be used (LPI solder mask, etc.), impedance requirements, lamination/material specifications, etc. are specified in the PCB manufacturing drawing. Complete and clear manufacturing instructions will help ensure that your design can be produced anywhere.
Your design may also need to be viewed by an assembler to ensure that the design can be reliably produced without defects. The assembly drawing and BOM are used to quote the board and ensure accurate assembly after the assembler receives the bare board and components. The assembly drawing contains its own set of annotations that help the process and remove any ambiguity in manufacturing. Some additional data required during the manufacturing process may include mechanical models or 3D printing, as well as MCAD data for the housing. The data required depends on the level of service and scope of work required by the manufacturer. For example, in assembly, some radial or axial lead capacitors may need to bend on their side in a very specific direction; Your 3D printing and STEP files can clearly show this.
The orientation of these connectors can be easily displayed in the STEP file. This can be included in your standard PCB design output file, or it can be reflected by an appropriately sized outline in the assembly layer. Another specialized assembly requirement is the press-fit connector or crimp connector, which does not apply in standard PCB assembly procedures. Documentation about these components is also required; Assembly drawings or requirement-specific documents are probably best. If you are unsure or you are working with a new manufacturer, be sure to request this information and provide the correct data accordingly. At any time documentation is missing or important manufacturing/assembly requirements are not clearly stated, your manufacturer is likely to provide some "standard" features and requirements that apply to most basic designs. If you're not worried about issues like surface plating or solder resistance layer requirements, just focus on creating the main manufacturing documents and leave the rest to the manufacturer. Different companies offer different levels of service, all willing to help you successfully manufacture your first PCBA.
English
Chinese