{"id":6607,"date":"2025-07-01T09:13:38","date_gmt":"2025-07-01T09:13:38","guid":{"rendered":"https:\/\/lp.szlogic.cn\/glossary\/through-hole-reflow-soldering-process\/"},"modified":"2026-06-22T09:22:38","modified_gmt":"2026-06-22T09:22:38","slug":"through-hole-reflow-soldering-process","status":"publish","type":"post","link":"https:\/\/resources.l-p.com\/ru\/glossary\/through-hole-reflow-soldering-process","title":{"rendered":"What is Through\u2011Hole Reflow Soldering and How Does It Work"},"content":{"rendered":"<figure class=\"wp-block-image aligncenter size-large\"><img fetchpriority=\"high\" decoding=\"async\" width=\"1200\" height=\"712\" src=\"https:\/\/resources.l-p.com\/wp-content\/uploads\/2026\/05\/38595c55e1b241ab9884b65331c6903b.webp\" alt=\"What is Through\u2011Hole Reflow Soldering and How Does It Work\" class=\"wp-image-6604\" srcset=\"https:\/\/resources.l-p.com\/wp-content\/uploads\/2026\/05\/38595c55e1b241ab9884b65331c6903b.webp 1200w, https:\/\/resources.l-p.com\/wp-content\/uploads\/2026\/05\/38595c55e1b241ab9884b65331c6903b-300x178.webp 300w, https:\/\/resources.l-p.com\/wp-content\/uploads\/2026\/05\/38595c55e1b241ab9884b65331c6903b-1024x608.webp 1024w, https:\/\/resources.l-p.com\/wp-content\/uploads\/2026\/05\/38595c55e1b241ab9884b65331c6903b-768x456.webp 768w, https:\/\/resources.l-p.com\/wp-content\/uploads\/2026\/05\/38595c55e1b241ab9884b65331c6903b-18x12.webp 18w\" sizes=\"(max-width: 1200px) 100vw, 1200px\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Through\u2011Hole Reflow Soldering, also called pin-in-paste or intrusive soldering, lets you solder both through-hole and surface-mount parts in one reflow process. <strong>Through\u2011Hole Reflow Soldering (THR)<\/strong> offers exactly this: a hybrid process that marries the durability of <a target=\"_blank\" rel=\"\" href=\"https:\/\/resources.l-p.com\/ru\/glossary\/what-is-tht-through-hole-technology\/\">Through\u2011Hole Technology (THT)<\/a> with the speed and automation of <a target=\"_blank\" rel=\"\" href=\"https:\/\/resources.l-p.com\/ru\/glossary\/what-does-smt-surface-mount-technology-mean\/\">Surface\u2011Mount Technology (SMT)<\/a>. This method works well with SMT assembly lines. Market reports show that reflow soldering, including through-hole applications, increases efficiency and sees growing use in electronics manufacturing.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" >Background: Why THR Matters<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><p><strong>THT (Through\u2011Hole Technology)<\/strong> involves placing component leads through PCB holes and soldering from the underside. This method delivers <strong>strong mechanical interconnections<\/strong>, ideal for connectors, power components, or high\u2011stress environments.<\/p><\/li><li><p><strong>SMT (Surface\u2011Mount Technology)<\/strong> places components on the board surface with solder paste and reflows them in an oven\u2014efficient, precise, and suited for miniaturization.<\/p><\/li><li><p><strong>THR<\/strong> combines both: THT\u2010style components are equipped to be reflow\u2010soldered alongside SMT parts, enabling a single, streamlined production flow without wave\u2011soldering.<\/p><\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\" >THR Process Overview<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Through-hole reflow soldering integrates seamlessly into standard SMT production lines. The typical workflow includes the following steps:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><p><strong>Step 1:<\/strong> The PCB is fabricated with<strong> plated-through holes (PTH)<\/strong>, ensuring proper metallization for soldering.<\/p><\/li><li><p><strong>Step 2:<\/strong> On the SMT line, the board is aligned under a solder paste stencil in preparation for printing.<\/p><\/li><li><p><strong>Steps 3\u20134:<\/strong> During the solder paste printing stage, the paste is applied across the stencil, filling both the surface-mount pads and partially entering the PTHs.<\/p><\/li><li><p><strong>Steps 5\u20136:<\/strong> Components are placed using an automated pick-and-place machine. <a target=\"_blank\" rel=\"\" href=\"https:\/\/resources.l-p.com\/ru\/search\/?keyword=SMD\">Surface-mount devices (SMDs)<\/a> are positioned first. If the machine is not capable of placing the through-hole components, they are inserted manually after the SMDs. The leads pass through the holes filled with solder paste, where some paste adheres to the pins, while most remains inside the holes.<\/p><\/li><li><p><strong>Steps 7\u20138:<\/strong> The board then enters the reflow oven. As the temperature rises, the solder paste melts and flows around the component leads and into the plated hole walls. A reliable solder joint is formed through the creation of an intermetallic compound (IMC) between the component lead, the solder, and the copper plating inside the hole.<\/p><\/li>\n<\/ul>\n\n\n\n<figure class=\"wp-block-image aligncenter size-large\"><img decoding=\"async\" width=\"1200\" height=\"667\" src=\"https:\/\/resources.l-p.com\/wp-content\/uploads\/2026\/05\/b65b80309a1442debbe84f9a526ffbc2.webp\" alt=\"THR Process\" class=\"wp-image-6605\" srcset=\"https:\/\/resources.l-p.com\/wp-content\/uploads\/2026\/05\/b65b80309a1442debbe84f9a526ffbc2.webp 1200w, https:\/\/resources.l-p.com\/wp-content\/uploads\/2026\/05\/b65b80309a1442debbe84f9a526ffbc2-300x167.webp 300w, https:\/\/resources.l-p.com\/wp-content\/uploads\/2026\/05\/b65b80309a1442debbe84f9a526ffbc2-1024x569.webp 1024w, https:\/\/resources.l-p.com\/wp-content\/uploads\/2026\/05\/b65b80309a1442debbe84f9a526ffbc2-768x427.webp 768w, https:\/\/resources.l-p.com\/wp-content\/uploads\/2026\/05\/b65b80309a1442debbe84f9a526ffbc2-18x10.webp 18w\" sizes=\"(max-width: 1200px) 100vw, 1200px\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">This streamlined process allows both SMD and through-hole components to be soldered in a single reflow cycle, reducing manufacturing steps while ensuring robust mechanical and electrical connections\u2014particularly important for high-reliability parts such as LINK-PP&#8217;s THR-compatible RJ45 connectors.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" >Benefits of THR<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><p><strong>Mechanical Integrity<\/strong><br\/>Through\u2011hole leads anchor into the board, securing larger or high\u2011stress components\u2014like RJ45 connectors\u2014against vibration and handling.<\/p><\/li><li><p><strong>One\u2011Step Assembly<\/strong><br\/>THR eliminates wave soldering, enabling SMT and THR parts to be processed together on the reflow line\u2014saving time, reducing labor, and slashing costs.<\/p><\/li><li><p><strong>Scalability<\/strong><br\/>By leveraging automated SMT lines, THR suits both small and large production runs\u2014ideal for EMS providers and mixed-volume OEMs.<\/p><\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator\" \/>\n\n\n\n<h3 class=\"wp-block-heading\" >Design Considerations &amp; Best Practices<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Success with THR depends on thoughtful PCB and component engineering:<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" >Component Requirements<\/h4>\n\n\n\n<h4 class=\"wp-block-heading\" >Materials must withstand reflow temperatures (typically up to 260\u202f\u00b0C). LINK\u2011PP\u2019s <strong>LPJG0926HENLS4R PoE+ RJ45 connector<\/strong> uses high-temp thermoplastics and leads optimized for THR.<\/h4>\n\n\n\n<h4 class=\"wp-block-heading\" >Stand\u2011Off &amp; Lead Design<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">A stand\u2011off from the board allows paste to wick and improve airflow. Pin length must be carefully calibrated\u2014too long, and paste extrusion causes defects; too short, and joints fail IPC\u2011610 criteria.<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" >Paste Stencil Design<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">Ensure paste fills appropriately: high\u2011viscosity paste helps fill holes and prevents voids, as recommended in <a target=\"_blank\" rel=\"\" href=\"https:\/\/www.l-p.com\/\">LINK\u2011PP<\/a>\u2019s THR support literature .<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" >Reflow Profile<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">Use a controlled ramp\u2013soak\u2013peak\u2013cool curve. Ensure paste reaches liquidus, activating flux and avoiding thermal shock to components.<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" >Inspection &amp; Standards<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">Finalize quality using AOI, x\u2011ray, and IPC\u2011610 criteria. THR joints should show \u226575\u202f% solder coverage with &lt;30\u202f% voids.<\/p>\n\n\n\n<hr class=\"wp-block-separator\" \/>\n\n\n\n<h3 class=\"wp-block-heading\" >&#x1f4e6; LINK\u2011PP\u2019s THR\u2011Ready Connectors<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">LINK\u2011PP designs several THR\u2011compatible RJ45 connectors\u2014especially the <a target=\"_blank\" rel=\"\" href=\"https:\/\/www.l-p.com\/products\/478673.htm\"><strong>LPJG0926HENLS4R<\/strong><\/a><strong> PoE+ RJ45<\/strong>\u2014with:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><p><strong>High-temp housing (PA46 + 30\u202f% glass)<\/strong> enduring 260\u202f\u00b0C reflow for 10\u202fs.<\/p><\/li><li><p><strong>1.25\u202fmm stand\u2011off<\/strong> for airflow and paste flow.<\/p><\/li><li><p><strong>2.40\u202fmm pin length<\/strong> suited to typical 1.6\u202fmm PCBs.<\/p><\/li><li><p><strong>High-viscosity paste compatibility<\/strong>, reducing voids and enhancing joint reliability.<\/p><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">These features ensure LINK\u2011PP\u2019s THR connectors meet IPC\u2011610, offering high durability and strong electrical performance in harsh environments.<\/p>\n\n\n\n<hr class=\"wp-block-separator\" \/>\n\n\n\n<h2 class=\"wp-block-heading\" > Typical Applications<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><p><strong>Networking &amp; Telecom<\/strong>: High-density RJ45 ports benefit from THR\u2019s mechanical stability plus SMT line speed.<\/p><\/li><li><p><strong>Industrial &amp; Automotive<\/strong>: Vibration resistance and high-current tolerance mesh well with THR\u2019s strengths.<\/p><\/li><li><p><strong>EMS &amp; High\u2011Volume Production<\/strong>: A single reflow pass boosts throughput and reduces capital expenditure.<\/p><\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator\" \/>\n\n\n\n<h2 class=\"wp-block-heading\" >THR vs. THT vs. SMT at a Glance<\/h2>\n\n\n\n<figure class=\"wp-block-table\">\n<table class=\"has-fixed-layout\">\n<colgroup><col style=\"min-width: 25px;\"\/><col style=\"width: 180px;\"\/><col style=\"min-width: 25px;\"\/><col style=\"min-width: 25px;\"\/><\/colgroup><tbody><tr><th colspan=\"1\" rowspan=\"1\"><p>Technology<\/p><\/th><th colspan=\"1\" rowspan=\"1\" colwidth=\"180\"><p>Assembly Method<\/p><\/th><th colspan=\"1\" rowspan=\"1\"><p>Strengths<\/p><\/th><th colspan=\"1\" rowspan=\"1\"><p>Limitations<\/p><\/th><\/tr><tr><td colspan=\"1\" rowspan=\"1\"><p><strong>THT<\/strong><\/p><\/td><td colspan=\"1\" rowspan=\"1\" colwidth=\"180\"><p>Leads + wave solder<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>Extremely robust mechanical joints<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>Manual labor, no SMT integration<\/p><\/td><\/tr><tr><td colspan=\"1\" rowspan=\"1\"><p><strong>SMT<\/strong><\/p><\/td><td colspan=\"1\" rowspan=\"1\" colwidth=\"180\"><p>Paste + reflow<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>Compact, fast, automated<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>Less mechanical durability<\/p><\/td><\/tr><tr><td colspan=\"1\" rowspan=\"1\"><p><strong>THR<\/strong><\/p><\/td><td colspan=\"1\" rowspan=\"1\" colwidth=\"180\"><p>Paste + reflow (hole)<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>Mechanical + automated efficiency<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>Requires THR\u2011rated parts, process tweaks<\/p><\/td><\/tr><\/tbody>\n<\/table>\n<\/figure>\n\n\n\n<h3 class=\"wp-block-heading\" >Why Choose THR?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">THR strikes a compelling balance: it maintains the mechanical resilience of through\u2011hole mounts while harnessing the rapid, automated reflow process of SMT. For multi\u2011component PCBs\u2014especially those including heavy connectors like <a target=\"_blank\" rel=\"\" href=\"https:\/\/www.l-p.com\/store-17492-integrated-rj45-connector.htm\">RJ45<\/a>\u2014THR is the strategic choice.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">When you use <strong>LINK\u2011PP\u2019s THR\u2011optimized RJ45 series<\/strong>, you ensure reliable soldering, consistent quality, and streamlined production workflows\u2014all backed by rigorous design and industry-certified standards.<\/p>\n\n\n\n<hr class=\"wp-block-separator\" \/>\n\n\n\n<h3 class=\"wp-block-heading\" >&#x1f3c1; Conclusion<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Through\u2011Hole Reflow Soldering (THR)<\/strong> is a forward\u2011looking hybrid soldering technology that offers the best of both worlds: <strong>durable mechanical joints and high\u2011efficiency SMT assembly<\/strong>. By designing for THR\u2014at the component, PCB, paste, and process level\u2014manufacturers can reduce costs, improve yields, and deliver greater reliability.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">At LINK\u2011PP, THR\u2011capable components exemplify this philosophy. From material selection to stand\u2011off geometry and paste compatibility, every detail supports a smoother reflow process and stronger end products. Discover LINK\u2011PP\u2019s THR solutions\u2014built for performance, designed for scale, and ready for tomorrow\u2019s high\u2011stress environments.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" >FAQ<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\" >What is the main advantage of Through\u2011Hole Reflow Soldering?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">You can solder both through-hole and surface-mount parts in one process. This method saves time and increases efficiency on your assembly line.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" >What types of components work best with Through\u2011Hole Reflow Soldering?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">You should use components that can handle high temperatures. Most connectors, switches, and large capacitors work well with this process.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" >What happens if you use too little solder paste?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">You may see weak joints or incomplete hole filling. Always check paste volume to ensure strong, reliable solder connections.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" >See Also<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\"><a target=\"_blank\" href=\"https:\/\/resources.l-p.com\/ru\/glossary\/what-is-tht-through-hole-technology\/\">A Comprehensive Guide To Through-Hole Technology Explained<\/a><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><a target=\"_blank\" href=\"https:\/\/resources.l-p.com\/ru\/glossary\/understanding-surface-mount-device-smd\/\">Exploring Surface-Mount Devices And Their Role In Electronics<\/a><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><a target=\"_blank\" href=\"https:\/\/resources.l-p.com\/ru\/glossary\/what-does-smt-surface-mount-technology-mean\/\">Decoding The Meaning And Importance Of SMT Technology<\/a><\/p>","protected":false},"excerpt":{"rendered":"<p>Through\u2011Hole Reflow Soldering enables simultaneous soldering of through-hole and surface-mount components in a single efficient reflow process.<\/p>","protected":false},"author":1,"featured_media":6606,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[27],"tags":[22],"class_list":["post-6607","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-glossary","tag-integrated-rj45-connectors"],"blocksy_meta":[],"acf":[],"_links":{"self":[{"href":"https:\/\/resources.l-p.com\/ru\/wp-json\/wp\/v2\/posts\/6607","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/resources.l-p.com\/ru\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/resources.l-p.com\/ru\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/resources.l-p.com\/ru\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/resources.l-p.com\/ru\/wp-json\/wp\/v2\/comments?post=6607"}],"version-history":[{"count":7,"href":"https:\/\/resources.l-p.com\/ru\/wp-json\/wp\/v2\/posts\/6607\/revisions"}],"predecessor-version":[{"id":11440,"href":"https:\/\/resources.l-p.com\/ru\/wp-json\/wp\/v2\/posts\/6607\/revisions\/11440"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/resources.l-p.com\/ru\/wp-json\/wp\/v2\/media\/6606"}],"wp:attachment":[{"href":"https:\/\/resources.l-p.com\/ru\/wp-json\/wp\/v2\/media?parent=6607"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/resources.l-p.com\/ru\/wp-json\/wp\/v2\/categories?post=6607"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/resources.l-p.com\/ru\/wp-json\/wp\/v2\/tags?post=6607"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}