Application \/ Need<\/th>	Recommended Stiffener Thickness<\/th>	Typical Material<\/th><\/tr><\/thead>
Light SMT components, LEDs<\/td>	0.1\u20130.3 mm<\/td>	PI or thin FR4<\/td><\/tr>
Standard ZIF \/ FPC connectors<\/td>	0.4\u20130.8 mm<\/td>	FR4<\/td><\/tr>
Board-to-board connectors, heavy ICs<\/td>	0.8\u20131.2 mm<\/td>	FR4<\/td><\/tr>
High-vibration \/ shock resistance<\/td>	0.3\u20130.5 mm<\/td>	Stainless steel<\/td><\/tr>
Ultra-thin wearable designs<\/td>	0.125\u20130.25 mm<\/td>	PI<\/td><\/tr><\/tbody><\/table>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t \n\t\t\t\t\t\t\t\t\t Faustregel:<\/em> Stiffener should make the total thickness in that area ~0.8\u20131.6 mm for good SMT\/component support, but never exceed your mechanical envelope.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t \n\t\t\t\t \n\t\t\t\t\t\t\t \n\n\t\t\t\n\t\t\t \n\t\t\t\t Adhesive Layers<\/h3> \n\t\t\t\t\t\t\t<\/div>\n\n\t\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t \n\t\t\t\t\t\t\t\t\t Stiffeners are bonded using adhesive:<\/p> Most common:<\/em> Acrylic or epoxy-based pressure-sensitive adhesive (PSA) films (e.g., 3M 9077, DuPont Pyralux)<\/p> Dicke:<\/em> Usually 25\u201350 \u00b5m per side<\/p> Types:<\/strong><\/p> Pre-applied PSA (easiest for prototyping<\/a>)<\/li> Thermoset adhesive (better long-term reliability, used in production)<\/li><\/ul> Key points:<\/strong><\/p> Adhesive must cover the entire stiffener area (no voids)<\/li> In rigid-flex, often use the same adhesive as coverlay bonding<\/li> Heat + pressure during lamination (avoid bubbles\/delamination)<\/li><\/ul>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\n\t\t\t\t \n\t\t\t\t\t\t\t \n\n\t\t\t\n\t\t\t \n\t\t\t\t Placement Rules<\/h3> \n\t\t\t\t\t\t\t<\/div>\n\n\t\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t \n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t $\"Correct$ \t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t \n\t\t\t\t\t\t\t\t\t Place stiffeners only under components\/connectors \u2014 never in dynamic bend zones<\/li> Keep stiffener edge at least 1\u20132 mm away from bend area (transition zone)<\/li> Overlap flex\/coverlay by ~1\u20132 mm for good adhesion and stress relief<\/li> Use rounded corners on stiffeners (radius \u2265 1 mm) to avoid stress risers<\/li> For connectors: Stiffener should extend beyond connector body by 1\u20132 mm on all sides<\/li> In rigid-flex, stiffeners often form part of the rigid section<\/li> If multiple stiffeners are used, space them to avoid creating weak flex “hinges” between them<\/li> If needed drill holes\/vias, place them only in stiffened areas<\/li><\/ul>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t \n\t\t\t\t \n\t\t\t\t\t\t\t \n\n\t\t\t\n\t\t\t \n\t\t\t\t Manufacturing Constraints<\/h2> \n\t\t\t\t\t\t\t<\/div>\n\n\t\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t \n\t\t\t\t\t\t\t\t\t Always submit your design files early for DFM review from your fabricator\u2014they’ll flag issues and suggest cost-saving tweaks (e.g., relax tolerances where possible). Following IPC-2223 and IPC-6013 standards helps hit the sweet spot between performance and manufacturability.<\/p> Flex PCB are significantly more expensive (often 3\u201310\u00d7 higher than equivalent rigid boards) due to several manufacturing and material factors:<\/p> Specialized Materials:<\/em> Polyimide (Kapton) substrates, adhesiveless laminates, and RA copper cost 3\u20138\u00d7 more than FR-4. PET is cheaper but limited to low-performance apps.<\/li> Complex Processes:<\/em> Extra steps like precise coverlay lamination, windowing\/punching, controlled impedance etching, and multiple cleaning\/inspection cycles. Laser processing for fine features or microvias adds cost.<\/li> Lower Yields:<\/em> Thin materials are prone to defects (wrinkles, delamination, alignment errors). Scrap rates are higher, especially for dynamic flex or multilayers.<\/li> Handling & Equipment:<\/em> Requires cleanrooms, specialized fixtures, and slower processing to avoid damage. Rigid lines can’t handle flex without modifications.<\/li> Low Volume \/ Customization:<\/em> Flex designs are often low-to-medium volume with high customization (bend areas, stiffeners), reducing economies of scale.<\/li> Testing & Qualification:<\/em> More rigorous flex-cycle, thermal shock, and adhesion testing (per IPC-6013) increases cost.<\/li><\/ul>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t \n\t\t\t\t \n\t\t\t\t\t\t\t \n\n\t\t\t\n\t\t\t \n\t\t\t\t Abschlie\u00dfende Gedanken<\/h2> \n\t\t\t\t\t\t\t<\/div>\n\n\t\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t \n\t\t\t\t\t\t\t\t\t Flexible PCB open up design possibilities that rigid boards simply cannot match\u2014from wearable devices to foldable phones and compact industrial electronics. However, achieving reliable and high-performance flex circuits requires careful attention to materials, stack-up, bend radius, trace layout, stiffeners, and manufacturing constraints. Every detail matters: a small mistake in bend zones or pad design can compromise the entire board\u2019s durability.<\/p> Bei PCBCool<\/a>, we turn complex flexible PCB designs into reliable products. Our team excels in every stage of the process\u2014design, manufacturing, and assembly\u2014ensuring your flex projects meet both technical and practical requirements.<\/p> We can produce boards from single-layer to 6 layers, with board thicknesses ranging from 0.037 mm to 4 mm and tight tolerances of \u00b10.03 mm, as well as minimum hole diameters down to 0.10 mm.<\/p> Whether your design involves dynamic flexing, high-density routing, or rigid-flex combinations, we have the expertise and equipment to deliver consistently high-quality results.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t \n\t\t\t\t\t \n\t\t\t\t \n\t\t\t\t \n\t\t\t\t\t\t\t \n\n\t\t\t\n\t\t\t \n\t\t\t\t H\u00e4ufig gestellte Fragen (FAQ)<\/h2> \n\t\t\t\t\t\t\t<\/div>\n\n\t\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t \n\t\t \n\t\t\t\t \n\t\t\t\t \n\t\t\t\t\t\n\t\t \n\t\t\t\t\t\t\t\n\t\t\t\t \n\t\t\t\t\t \n\t\t\t\t\t\t \n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\tQ1: What Is IPC-2223?\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/div>\n\n\t\t\t\t\t \n\t\t\t\t\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t A: IPC-2223 is the industry standard for flexible and rigid-flex PCB design, providing detailed rules to ensure reliability and manufacturability.<\/p>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\n\t\t\t\t \n\t\t\t\t\t \n\t\t\t\t\t\t \n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\tQ2: What Is a Stiffener?\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/div>\n\n\t\t\t\t\t \n\t\t\t\t\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t A: A stiffener is a rigid material added to a flex PCB to provide mechanical support under heavy or rigid components.<\/p>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\n\t\t\t\t \n\t\t\t\t\t \n\t\t\t\t\t\t \n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\tQ3: How Should Traces Be Routed in Bend Zones?\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/div>\n\n\t\t\t\t\t \n\t\t\t\t\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t A: Route traces parallel to the bend axis (0\u00b0). If unavoidable, use 45\u00b0 angles or curves to distribute stress evenly.<\/p>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t \n\t\t\t\t \n\t\t\t\t \n\t\t\t\t\t\n\t\t \n\t\t\t\t\t\t\t\n\t\t\t\t \n\t\t\t\t\t \n\t\t\t\t\t\t \n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\tQ4: Should I Use Teardrops or Fillets at Trace Ends?\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/div>\n\n\t\t\t\t\t \n\t\t\t\t\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t A: Yes. Teardrops and fillets at trace ends reduce strain and improve reliability in bend zones.<\/p>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\n\t\t\t\t \n\t\t\t\t\t \n\t\t\t\t\t\t \n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\tQ5: Why Should Components Avoid Bend Zones?\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/div>\n\n\t\t\t\t\t \n\t\t\t\t\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t A: Components are rigid; bending them causes solder joint cracks, component failure, or trace breaks underneath.<\/p>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\n\t\t\t\t \n\t\t\t\t\t \n\t\t\t\t\t\t \n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\tQ6: How Can I Place Components Safely on a Flex PCB?\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/div>\n\n\t\t\t\t\t \n\t\t\t\t\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t A: Use rigid islands with stiffeners under components, or mount components on rigid sections in rigid-flex designs.<\/p>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\n\t\t\t\t \n\t\t\t\t\t \n\t\t\t\t\t\t \n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\tQ7: What Areas Need Stiffeners?\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/div>\n\n\t\t\t\t\t \n\t\t\t\t\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t A: Anywhere heavy or rigid components are mounted, such as connectors, ICs, LEDs, sensors, or buttons.<\/p>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t \n\t\t\t\t\t\t\t \t\t\t\n\t\t\t\t\t \n\t\t\t\t \n\t\t\t\t\t \n\t\t \n\t\t \n\t\t\t\t \n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t $\"Sam$ \t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t \n\t\t\t\t \n\t\t\t\t \n\t\t\t\t\t\t\t \n\n\t\t\t\n\t\t\t \n\t\t\t\t Sam K \| Embedded Systems Engineer<\/div> \n\t\t\t\t\t\t\t<\/div>\n\n\t\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t \n\t\t\t\t \n\t\t\t\t\t\t\t\t\t Sam K arbeitet an eingebetteten elektronischen Systemen mit Schwerpunkt auf Hardware-Design, PCB-Entwicklung, Firmware-Programmierung und Systemintegration. Er unterst\u00fctzt auch die Leistungsoptimierung und hilft bei der Umsetzung von Ideen f\u00fcr elektronische Produkte in zuverl\u00e4ssige, praxistaugliche L\u00f6sungen.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t \n\t\t\t\t\t \r\n Weitere Artikel von Sam K lesen \u2192<\/a>\r\n<\/div>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>","protected":false},"excerpt":{"rendered":" Ein vollst\u00e4ndiger Leitfaden zur Konstruktion flexibler Leiterplatten f\u00fcr die Produktion: Behandelt Materialien, Stapellagen, Biegeradien, Leiterplattenlayouts, Versteifungen und bew\u00e4hrte Herstellungsverfahren.<\/p>","protected":false},"author":11,"featured_media":43040,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"slim_seo":{"title":"Practical Flexible PCB Design Guide for Production \| PCBCool","description":"Ein vollst\u00e4ndiger Leitfaden zur Konstruktion flexibler Leiterplatten f\u00fcr die Produktion: Behandelt Materialien, Stapellagen, Biegeradien, Leiterplattenlayouts, Versteifungen und bew\u00e4hrte Herstellungsverfahren."},"footnotes":""},"categories":[113],"tags":[147,122,125],"post_folder":[],"class_list":["post-42823","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-technical-guides","tag-flexible-pcb","tag-pcb-design","tag-pcb-technical-specs"],"_links":{"self":[{"href":"https:\/\/pcbcool.com\/de\/wp-json\/wp\/v2\/posts\/42823","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pcbcool.com\/de\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/pcbcool.com\/de\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/pcbcool.com\/de\/wp-json\/wp\/v2\/users\/11"}],"replies":[{"embeddable":true,"href":"https:\/\/pcbcool.com\/de\/wp-json\/wp\/v2\/comments?post=42823"}],"version-history":[{"count":1,"href":"https:\/\/pcbcool.com\/de\/wp-json\/wp\/v2\/posts\/42823\/revisions"}],"predecessor-version":[{"id":43117,"href":"https:\/\/pcbcool.com\/de\/wp-json\/wp\/v2\/posts\/42823\/revisions\/43117"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/pcbcool.com\/de\/wp-json\/wp\/v2\/media\/43040"}],"wp:attachment":[{"href":"https:\/\/pcbcool.com\/de\/wp-json\/wp\/v2\/media?parent=42823"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/pcbcool.com\/de\/wp-json\/wp\/v2\/categories?post=42823"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/pcbcool.com\/de\/wp-json\/wp\/v2\/tags?post=42823"},{"taxonomy":"post_folder","embeddable":true,"href":"https:\/\/pcbcool.com\/de\/wp-json\/wp\/v2\/post_folder?post=42823"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}