{"id":23891,"date":"2026-04-15T18:43:34","date_gmt":"2026-04-15T10:43:34","guid":{"rendered":"https:\/\/www.bestpcbs.com\/blog\/?p=23891"},"modified":"2026-04-15T18:43:35","modified_gmt":"2026-04-15T10:43:35","slug":"fiducial-marks-pcb","status":"publish","type":"post","link":"https:\/\/www.bestpcbs.com\/blog\/2026\/04\/fiducial-marks-pcb\/","title":{"rendered":"Are Fiducial Marks PCB Essential? A Complete Guide To PCB Fiducial Markers"},"content":{"rendered":"<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_82_2 ez-toc-wrap-left counter-hierarchy ez-toc-counter ez-toc-grey ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Table of Contents<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/www.bestpcbs.com\/blog\/2026\/04\/fiducial-marks-pcb\/#Are_Fiducial_Marks_Necessary_For_PCB\" >Are Fiducial Marks Necessary For PCB?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/www.bestpcbs.com\/blog\/2026\/04\/fiducial-marks-pcb\/#What_is_The_Purpose_Of_Fiducial_Marks_On_PCB\" >What is The Purpose Of Fiducial Marks On PCB?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/www.bestpcbs.com\/blog\/2026\/04\/fiducial-marks-pcb\/#Where_To_Place_Fiducials_On_A_PCB\" >Where To Place Fiducials On A PCB?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/www.bestpcbs.com\/blog\/2026\/04\/fiducial-marks-pcb\/#How_Do_You_Design_A_Good_Fiducial_Marker_For_PCB\" >How Do You Design A Good Fiducial Marker For PCB?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/www.bestpcbs.com\/blog\/2026\/04\/fiducial-marks-pcb\/#How_To_Add_Fiducial_In_PCB_Design\" >How To Add Fiducial In PCB Design?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/www.bestpcbs.com\/blog\/2026\/04\/fiducial-marks-pcb\/#What_is_The_Standard_Fiducial_Size_For_PCB\" >What is The Standard Fiducial Size For PCB?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/www.bestpcbs.com\/blog\/2026\/04\/fiducial-marks-pcb\/#What_Do_Fiducial_Markers_On_PCB_Look_Like_In_Practical_Applications\" >What Do Fiducial Markers On PCB Look Like In Practical Applications?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/www.bestpcbs.com\/blog\/2026\/04\/fiducial-marks-pcb\/#What_Are_The_Different_Types_Of_Fiducial_Markers_For_PCB\" >What Are The Different Types Of Fiducial Markers For PCB?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/www.bestpcbs.com\/blog\/2026\/04\/fiducial-marks-pcb\/#How_Do_You_Prepare_For_Fiducial_Markers_On_PCB_Manufacturing\" >How Do You Prepare For Fiducial Markers On PCB Manufacturing?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-10\" href=\"https:\/\/www.bestpcbs.com\/blog\/2026\/04\/fiducial-marks-pcb\/#What_Are_The_Key_Considerations_For_Fiducial_Marker_Placement_PCB\" >What Are The Key Considerations For Fiducial Marker Placement PCB?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-11\" href=\"https:\/\/www.bestpcbs.com\/blog\/2026\/04\/fiducial-marks-pcb\/#FAQs_About_Fiducial_Marks_PCB\" >FAQs About Fiducial Marks PCB<\/a><\/li><\/ul><\/nav><\/div>\n<div class=\"yzp-no-index\"><\/div>\n<p>Do you know why even the most advanced SMT assembly lines rely on small copper dots called<strong> <a href=\"https:\/\/www.bestpcbs.com\/blog\/2026\/04\/fiducial-marks-pcb\/\" title=\"\">fiducial marks PCB<\/a><\/strong>? For any PCB undergoing automated assembly, fiducial markers are not optional, they are the foundation of precision, reducing defects, speeding up production, and ensuring your design meets strict manufacturing standards. <\/p>\n\n\n\n<p>This guide breaks down everything you need to know about<a href=\"https:\/\/www.bestpcbs.com\/blog\/2026\/04\/fiducial-marks-pcb\/\" title=\"\"> <strong>fiducial marks PCB<\/strong><\/a>, from their purpose and design rules to placement strategies and manufacturing preparation, to help you create reliable, assembly-ready PCBs.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><a href=\"https:\/\/www.bestpcbs.com\/blog\/wp-content\/uploads\/2026\/04\/Fiducial-Marks-PCB.jpg\"><img decoding=\"async\" src=\"https:\/\/www.bestpcbs.com\/blog\/wp-content\/uploads\/2026\/04\/Fiducial-Marks-PCB.jpg\" alt=\"Fiducial Marks PCB, https:\/\/www.bestpcbs.com\/blog\/2026\/04\/fiducial-marks-pcb\/\" class=\"wp-image-23897\" style=\"aspect-ratio:3\/2;object-fit:contain;width:800px\"\/><\/a><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Are_Fiducial_Marks_Necessary_For_PCB\"><\/span>Are Fiducial Marks Necessary For PCB?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p><strong><a href=\"https:\/\/www.bestpcbs.com\/blog\/2026\/04\/fiducial-marks-pcb\/\" title=\"\">Fiducial marks<\/a><\/strong> are <strong>essential for all PCBs using automated SMT assembly<\/strong>, and they are highly recommended for any design that requires precise component placement. Even with modern manufacturing technology, fiducials remain non-negotiable because they solve critical alignment challenges that alternative methods cannot address. <\/p>\n\n\n\n<p>Without fiducials, assembly machines struggle to compensate for board stretch, rotation, or minor misalignment, leading to misplaced components, solder bridges, tombstoning, and high rejection rates. For through-hole-only boards or manual assembly, fiducials are not required, but they are still useful for future automation or inspection.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"What_is_The_Purpose_Of_Fiducial_Marks_On_PCB\"><\/span>What is The Purpose Of Fiducial Marks On PCB?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p><strong><a href=\"https:\/\/www.bestpcbs.com\/blog\/2026\/04\/fiducial-marks-pcb\/\" title=\"\">Fiducial marks<\/a><\/strong> are <strong>high-contrast, exposed copper reference points<\/strong> that act as a GPS for SMT machines, enabling precise alignment and calibration. Their core purpose is to provide a consistent, accurate reference for automated equipment, with three key functions:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Board Alignment &amp; Orientation<\/strong>: Vision cameras scan fiducials to calculate the PCB\u2019s exact X\/Y position, rotation angle, and scale (compensating for board stretch\/shrinkage).<\/li>\n\n\n\n<li><strong>Component Placement Precision<\/strong>: For fine-pitch parts (BGAs, QFPs, 01005 components), fiducials ensure placement accuracy down to 0.05mm, eliminating errors from manufacturing tolerances.<\/li>\n\n\n\n<li><strong>Quality Control<\/strong>: AOI and SPI systems use fiducials to verify component placement and solder paste application, reducing false rejects and ensuring consistent quality.<\/li>\n<\/ul>\n\n\n\n<ol start=\"1\" class=\"wp-block-list\"><\/ol>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Where_To_Place_Fiducials_On_A_PCB\"><\/span>Where To Place Fiducials On A PCB?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>Fiducial placement directly impacts assembly accuracy, follow these rules for optimal results:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Global Fiducials<\/strong>: Use <strong>3 asymmetric marks<\/strong> in an <strong>L-shape<\/strong> (e.g., lower-left, upper-left, upper-right corners). Avoid symmetric layouts (all four corners) to prevent 180\u00b0 orientation confusion.<\/li>\n\n\n\n<li><strong>Edge Clearance<\/strong>: Maintain a <strong>minimum 5mm distance<\/strong> from the board edge to avoid obstruction by conveyor rails or clamping fixtures.<\/li>\n\n\n\n<li><strong>Clearance Zone<\/strong>: Keep a <strong>2\u20133mm radius<\/strong> around each fiducial completely free of traces, vias, silkscreen, or other copper features to ensure unobstructed vision recognition.<\/li>\n\n\n\n<li><strong>Local Fiducials<\/strong>: For components with \u22640.5mm pitch (BGAs, QFPs), place <strong>2 diagonal fiducials<\/strong> 1\u20133mm from the component\u2019s corners.<\/li>\n\n\n\n<li><strong>Double-Sided Boards<\/strong>: Add fiducials on <strong>both top and bottom layers<\/strong> (offset to avoid light interference).<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"How_Do_You_Design_A_Good_Fiducial_Marker_For_PCB\"><\/span>How Do You Design A Good Fiducial Marker For PCB?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>A well-designed fiducial ensures reliable machine vision detection and consistent assembly. Follow these design principles:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Shape<\/strong>: <strong>Solid circle<\/strong> (preferred) for maximum rotational symmetry and recognition reliability. Avoid crosses, squares, or complex shapes unless verified with your assembler.<\/li>\n\n\n\n<li><strong>Size<\/strong>: Standard copper diameter is <strong>1.0mm<\/strong> (range: 0.8\u20131.5mm). Use 1.5\u20132.0mm for large boards or panels.<\/li>\n\n\n\n<li><strong>Solder Mask Opening<\/strong>: Concentric opening <strong>2.0mm<\/strong> (for 1.0mm copper) to create high contrast between exposed copper and solder mask.<\/li>\n\n\n\n<li><strong>Surface Finish<\/strong>: Use <strong>ENIG (gold plating)<\/strong> or <strong>HASL (tin plating)<\/strong> for high reflectivity and oxidation resistance. Bare copper is acceptable but requires anti-oxidation coating.<\/li>\n\n\n\n<li><strong>Consistency<\/strong>: All fiducials on the same board must be identical in size (\u00b125\u00b5m tolerance).<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"How_To_Add_Fiducial_In_PCB_Design\"><\/span>How To Add Fiducial In PCB Design?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>Adding fiducials is straightforward in all major EDA tools (Altium Designer, KiCad, Eagle). Follow this step-by-step process:<\/p>\n\n\n\n<p><strong>Step 1: Select Layer: <\/strong>Choose the copper layer (Top\/Bottom Layer) where fiducials will be placed.<br><strong>Step 2: Create Pad: <\/strong>Add a non-plated SMD pad with your chosen diameter (1.0mm standard).<br><strong>Step 3: Solder Mask Opening: <\/strong>Draw a concentric circle on the solder mask layer (Top\/Bottom Solder Mask) with a diameter twice the copper pad.<br><strong>Step 4: Place Fiducials:<\/strong> Position 3 global fiducials in an L-shape, 5mm from board edges. Add local fiducials near fine-pitch components.<br><strong>Step 5: Clearance Zone:<\/strong> Ensure 2\u20133mm radius around each fiducial is free of traces, vias, or silkscreen.<br><strong>Step 6: Label &amp; Verify: <\/strong>Label fiducials (FID1, FID2) and run DRC to check for violations.<br><strong>Step 7: Export Files: <\/strong>Include fiducials in Gerber\/ODB++ and pick-and-place data.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"What_is_The_Standard_Fiducial_Size_For_PCB\"><\/span>What is The Standard Fiducial Size For PCB?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>The standard fiducial size follows IPC-7351 and SMEMA guidelines:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Global Fiducials<\/strong>: <strong>1.0mm copper diameter<\/strong> (most common) with <strong>2.0mm solder mask opening<\/strong>.<\/li>\n\n\n\n<li><strong>Local Fiducials<\/strong>: <strong>1.0mm copper diameter<\/strong> (same as global).<\/li>\n\n\n\n<li><strong>Large Boards\/Panels<\/strong>: <strong>1.5\u20132.0mm copper diameter<\/strong> for improved visibility.<\/li>\n\n\n\n<li><strong>HDI\/High-Density Designs<\/strong>: <strong>0.8mm copper diameter<\/strong> (confirm with assembler).<\/li>\n\n\n\n<li><strong>Clearance Zone<\/strong>: <strong>3.0mm minimum radius<\/strong> (2\u20133\u00d7 copper diameter).<\/li>\n<\/ul>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><a href=\"https:\/\/www.bestpcbs.com\/blog\/wp-content\/uploads\/2026\/04\/Fiducial-Marks-PCB-1.jpg\"><img decoding=\"async\" src=\"https:\/\/www.bestpcbs.com\/blog\/wp-content\/uploads\/2026\/04\/Fiducial-Marks-PCB-1.jpg\" alt=\"Fiducial Marks PCB, https:\/\/www.bestpcbs.com\/blog\/2026\/04\/fiducial-marks-pcb\/\" class=\"wp-image-23900\" style=\"width:800px\"\/><\/a><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"What_Do_Fiducial_Markers_On_PCB_Look_Like_In_Practical_Applications\"><\/span>What Do Fiducial Markers On PCB Look Like In Practical Applications?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>In practice, fiducial markers are small, round, exposed copper dots with a solder mask ring.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Global Fiducials<\/strong>: Larger (1.0\u20132.0mm) placed on board corners.<\/li>\n\n\n\n<li><strong>Local Fiducials<\/strong>: Smaller (1.0mm) near BGAs\/QFPs.<\/li>\n\n\n\n<li><strong>Panel Fiducials<\/strong>: On panel rails for array alignment.<\/li>\n\n\n\n<li><strong>Surface Finish<\/strong>: Gold or tin-plated for high contrast.<\/li>\n<\/ul>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><a href=\"https:\/\/www.bestpcbs.com\/blog\/wp-content\/uploads\/2026\/04\/Fiducial-Markers-On-PCB-.jpeg\"><img decoding=\"async\" src=\"https:\/\/www.bestpcbs.com\/blog\/wp-content\/uploads\/2026\/04\/Fiducial-Markers-On-PCB-.jpeg\" alt=\"Fiducial Markers On PCB, https:\/\/www.bestpcbs.com\/blog\/2026\/04\/fiducial-marks-pcb\/\" class=\"wp-image-23896\" style=\"width:800px\"\/><\/a><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"What_Are_The_Different_Types_Of_Fiducial_Markers_For_PCB\"><\/span>What Are The Different Types Of Fiducial Markers For PCB?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>Fiducials are categorized by function and placement:<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>Type<\/th><th>Location<\/th><th>Purpose<\/th><th>Quantity<\/th><\/tr><\/thead><tbody><tr><td><strong>Global Fiducials<\/strong><\/td><td>PCB corners\/edges<\/td><td>Board-level alignment, rotation, scale compensation<\/td><td>3 (L-shape)<\/td><\/tr><tr><td><strong>Local Fiducials<\/strong><\/td><td>Near fine-pitch components (BGA\/QFP)<\/td><td>Component-level precision<\/td><td>2 per component<\/td><\/tr><tr><td><strong>Panel Fiducials<\/strong><\/td><td>Panel rails\/frame<\/td><td>Entire array alignment<\/td><td>3\u20134 per panel<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"How_Do_You_Prepare_For_Fiducial_Markers_On_PCB_Manufacturing\"><\/span>How Do You Prepare For Fiducial Markers On PCB Manufacturing?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>Proper preparation ensures fiducials are manufacturable and recognizable:<\/p>\n\n\n\n<ol start=\"1\" class=\"wp-block-list\">\n<li><strong>Design Review<\/strong>: Verify size, placement, and clearance zones meet assembler requirements.<\/li>\n\n\n\n<li><strong>Surface Finish<\/strong>: Specify ENIG or HASL for high reflectivity.<\/li>\n\n\n\n<li><strong>Gerber Files<\/strong>: Ensure fiducials are included in copper and solder mask layers.<\/li>\n\n\n\n<li><strong>Fabrication Notes<\/strong>: Label fiducials as \u201cFiducial Markers\u201d and specify size\/clearance.<\/li>\n\n\n\n<li><strong>Quality Check<\/strong>: Confirm no silkscreen\/traces cover fiducials.<\/li>\n<\/ol>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"What_Are_The_Key_Considerations_For_Fiducial_Marker_Placement_PCB\"><\/span>What Are The Key Considerations For Fiducial Marker Placement PCB?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>Follow these critical rules to avoid common mistakes:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Asymmetric Placement<\/strong>: 3 global fiducials in L-shape (not symmetric).<\/li>\n\n\n\n<li><strong>Edge Distance<\/strong>: \u22655mm from board edges.<\/li>\n\n\n\n<li><strong>Clearance Zone<\/strong>: 2\u20133mm radius free of all features.<\/li>\n\n\n\n<li><strong>Consistent Size<\/strong>: All fiducials identical (\u00b125\u00b5m).<\/li>\n\n\n\n<li><strong>Double-Sided<\/strong>: Fiducials on both layers (offset).<\/li>\n\n\n\n<li><strong>Panelization<\/strong>: Fiducials on each sub-board and panel rails.<\/li>\n<\/ul>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><a href=\"https:\/\/www.bestpcbs.com\/blog\/wp-content\/uploads\/2026\/04\/Fiducial-Marks-PCB-2.jpg\"><img decoding=\"async\" src=\"https:\/\/www.bestpcbs.com\/blog\/wp-content\/uploads\/2026\/04\/Fiducial-Marks-PCB-2.jpg\" alt=\"Fiducial Marks PCB\" class=\"wp-image-23902\" style=\"aspect-ratio:3\/2;object-fit:contain;width:800px\"\/><\/a><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"FAQs_About_Fiducial_Marks_PCB\"><\/span>FAQs About Fiducial Marks PCB<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p><strong>Q1: Do I need fiducial marks for a single-sided board?<\/strong><\/p>\n\n\n\n<p>A1: <strong>Yes.<\/strong> Even single-sided assembly requires global fiducials for stencil printing and pick-and-place alignment.<\/p>\n\n\n\n<p><strong>Q2: Can I use a via or tooling hole as a fiducial?<\/strong><\/p>\n\n\n\n<p>A2: <strong>No. <\/strong>Vias\/holes are drilled separately, introducing registration errors. Fiducials are etched with copper traces for guaranteed accuracy.<\/p>\n\n\n\n<p><strong>Q3: How many fiducials do I need?<\/strong><\/p>\n\n\n\n<p>A3: <strong>3 global fiducials<\/strong> (L-shape) are recommended. 2 minimum (diagonal). Add local fiducials for \u22640.5mm pitch components.<\/p>\n\n\n\n<p><strong>Q4: What happens if I omit fiducials?<\/strong><\/p>\n\n\n\n<p>A4: <strong>Assembly machines may reject the board or use alternative references<\/strong>, leading to misalignment, defects, higher costs, and longer production times.<\/p>\n\n\n\n<p><strong>Q5: Are fiducials needed for through-hole-only boards?<\/strong><\/p>\n\n\n\n<p>A5: <strong>No.<\/strong> Fiducials are for automated SMT assembly. Through-hole manual\/automated insertion does not require them.<\/p>\n\n\n\n<p><strong>Q6: Can fiducials be covered by silkscreen?<\/strong><\/p>\n\n\n\n<p>A6: <strong>No. <\/strong>Silkscreen reduces contrast and causes recognition failures. Keep the entire fiducial area clear.<\/p>\n\n\n\n<p><strong>Q7: What is the minimum clearance around a fiducial?<\/strong><\/p>\n\n\n\n<p>A7: <strong>2\u20133mm radius<\/strong> (2\u20133\u00d7 copper diameter) free of traces, vias, silkscreen.<\/p>\n\n\n\n<p><strong>Q8: How do I add fiducials in Altium Designer?<\/strong><\/p>\n\n\n\n<p>A8: Place \u2192 Fiducial \u2192 Set size (1.0mm) \u2192 Place in L-shape \u2192 Add solder mask opening.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Do you know why even the most advanced SMT assembly lines rely on small copper dots called fiducial marks PCB? For any PCB undergoing automated assembly, fiducial markers are not optional, they are the foundation of precision, reducing defects, speeding up production, and ensuring your design meets strict manufacturing standards. This guide breaks down everything [&hellip;]<\/p>\n","protected":false},"author":33247,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_uf_show_specific_survey":0,"_uf_disable_surveys":false,"footnotes":""},"categories":[175,174,37],"tags":[531,5288,5287,5289],"class_list":["post-23891","post","type-post","status-publish","format-standard","hentry","category-best-pcb","category-bestpcb","category-faq","tag-fiducial-marks-pcb","tag-fiducial-pcb-mark","tag-pcb-fiducial-mark","tag-pcb-fiducial-marker-size"],"acf":[],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.bestpcbs.com\/blog\/wp-json\/wp\/v2\/posts\/23891","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.bestpcbs.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.bestpcbs.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.bestpcbs.com\/blog\/wp-json\/wp\/v2\/users\/33247"}],"replies":[{"embeddable":true,"href":"https:\/\/www.bestpcbs.com\/blog\/wp-json\/wp\/v2\/comments?post=23891"}],"version-history":[{"count":9,"href":"https:\/\/www.bestpcbs.com\/blog\/wp-json\/wp\/v2\/posts\/23891\/revisions"}],"predecessor-version":[{"id":23904,"href":"https:\/\/www.bestpcbs.com\/blog\/wp-json\/wp\/v2\/posts\/23891\/revisions\/23904"}],"wp:attachment":[{"href":"https:\/\/www.bestpcbs.com\/blog\/wp-json\/wp\/v2\/media?parent=23891"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bestpcbs.com\/blog\/wp-json\/wp\/v2\/categories?post=23891"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bestpcbs.com\/blog\/wp-json\/wp\/v2\/tags?post=23891"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}