| ∗∗∗∗- BARCODE · QR · DATAMATRIX MARKING |
| PCB identification and traceability from manufacturing through assembly, testing and shipping |
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| COMPARISON OF THE MOST COMMON MARKING TYPES |
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| TYPE | | FORMAT | RECOMMENDED USE | ADVANTAGES | LIMITATIONS | TYPICAL DATA |
| Barcode |  | Linear 1D | Labels, boxes, panels or PCBs with sufficient length; legacy systems | Low-cost scanners, easy implementation and fast reading | Low data density; requires more length; less tolerant of damage | Part number, batch, order or short serial number |
| QR |  | 2D matrix | Mobile access, documentation, after-sales service or visible identification where space allows | Widely recognized, broad compatibility and high data capacity | Typically takes up more space than Data Matrix for compact traceability | URL, instructions, product ID or record |
| Data Matrix |  | Compact 2D matrix | Individual identification of PCBs and components, and direct marking in limited space | High data density, error correction and widespread industrial use | Requires suitable scanners and verification; control module size and contrast | Unique serial number, batch, date, revision, production line and MES/ERP link |
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| TRACEABILITY APPLICATIONS AND USE CASES |
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| STAGE / INDUSTRY | | INFORMATION THAT CAN BE LINKED | | | | |
| PCB manufacturing |  | Manufacturer, laminate batch, panel, date, Gerber revision, processes and inspection results. | | | | |
| SMT/THT assembly |  | Production line, machine, program, solder paste, reflow profiles, operator and component batches. | | | | |
| Quality and testing |  | AOI, SPI, electrical test, ICT, functional test, results and release date. | | | | |
| Repair and service |  | Failure history, rework, replacements and firmware version. | | | | |
| Logistics and shipping |  | Order, customer, box, date, destination and delivery status. | | | | |
| Automotive / aerospace / medical |  | Unit-level and process traceability according to risk level, contract and applicable regulations. | | | | |
| Issue management |  | Identify affected batches, limit recalls and link defects to materials or processes. | | | | |
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| QUICK SELECTION GUIDE |
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| REQUIREMENT | | RECOMMENDED CHOICE | | | | |
| Very small code on a PCB |  | Data Matrix, after real-world testing of size, contrast and readability. | | | | |
| Phone scanning or access to documentation |  | QR. | | | | |
| Compatibility with logistics or existing 1D equipment | | Barcode. | | | | |
| Permanent marking without a label |  | Laser marking, after validating material, solder mask color, surface damage and readability. | | | | |
| Automated traceability |  | Unique code + post-marking verification + MES/ERP record. | | | | |
