{"id":33512,"date":"2025-03-21T17:26:41","date_gmt":"2025-03-21T09:26:41","guid":{"rendered":"https:\/\/www.ray-tron.com\/?p=33512"},"modified":"2025-03-21T17:26:48","modified_gmt":"2025-03-21T09:26:48","slug":"why-do-photovoltaic-solder-ribbons-choose-lead-free-tin-layer","status":"publish","type":"post","link":"https:\/\/www.ray-tron.com\/en\/why-do-photovoltaic-solder-ribbons-choose-lead-free-tin-layer\/","title":{"rendered":"Why do photovoltaic solder ribbons choose lead-free tin layer?"},"content":{"rendered":"<p>In recent years,<strong>Lead-free tin layer (such as SN100, SN-Ag)<\/strong> exist<a href=\"https:\/\/www.ray-tron.com\/en\/pvribbon\/\" data-internallinksmanager029f6b8e52c=\"43\" title=\"Photovoltaic welding ribbon\">Photovoltaic welding ribbon<\/a>The application of photovoltaic ribbon is becoming more and more extensive, mainly due to the requirements of environmental protection regulations, the development of new high-efficiency battery technology and the need to improve the long-term reliability of components. <strong>Lead-free tin layer<\/strong> The main reasons:<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>1. Comply with environmental regulations (RoHS &amp; REACH)<\/strong><\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">\u2705 <strong>Reduce lead pollution and comply with global environmental regulations<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>RoHS (EU Directive on Hazardous Substances)<\/strong> The use of lead (Pb) in electronic products is restricted, and many countries and regions (such as the European Union, China, the United States, etc.) have strict requirements on lead content.<\/li>\n\n\n\n<li><strong>REACH (EU Chemicals Regulation)<\/strong> The use of lead is also being gradually restricted, promoting the use of more lead-free materials.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">\u2705 <strong>Avoid compliance risks caused by future regulatory upgrades<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>The photovoltaic industry is moving towards a more environmentally friendly direction.<a href=\"https:\/\/www.ray-tron.com\/en\/\" data-internallinksmanager029f6b8e52c=\"14\" title=\"Photovoltaic modules\">Photovoltaic modules<\/a>Manufacturers are already moving toward lead-free solder ribbon to accommodate future regulatory requirements.<\/li>\n\n\n\n<li><strong>In the long run, lead-free solder strips are more in line with the trend of global sustainable development<\/strong>, to avoid future product export obstructions due to restrictions on lead-containing materials.<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>2. Improve the long-term reliability of PV panels<\/strong><\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">\u2705 <strong>Reduce solder joint embrittlement and improve durability<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Lead-free tin layer (such as SN100, SN-Ag)<\/strong> Compared with traditional SN60PB40, the solder joints have better crack resistance and longer thermal cycle life under high temperature and long-term use.<\/li>\n\n\n\n<li>Traditional lead-containing solder may develop tin whiskers or become embrittled under long-term light and temperature changes, affecting the service life of photovoltaic modules.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">\u2705 <strong>Better high temperature resistance<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Lead-free solder has a higher melting point (e.g. SN100 is about 232\u00b0C)<\/strong>, can withstand higher temperatures and is not prone to welding fatigue or breakage due to temperature changes in the long-term working environment.<\/li>\n\n\n\n<li>for <strong>HJT (Heterojunction)<\/strong> and <strong>TOPCon (Tunneling Oxide Passivated Contact)<\/strong> For new high-efficiency battery cells, lead-free solder strips can better meet the welding requirements of these batteries.<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>3. More suitable for new high-efficiency battery technology<\/strong><\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">\u2705 <strong>HJT, TOPCon, IBC and other high-efficiency batteries are more suitable for lead-free solder strips<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>HJT (Heterojunction Cell)<\/strong> Extremely sensitive to temperature, too high welding temperature will damage the cell structure. Therefore, HJT batteries are usually used <strong>Low temperature lead-free solder strip (such as low temperature tin-bismuth alloy SnBi)<\/strong>, to avoid damage caused by high temperature welding.<\/li>\n\n\n\n<li><strong>TOPCon (Tunneling Oxide Passivated Contact Cell)<\/strong> and <strong>IBC (Insulated Back Contact Battery)<\/strong> Due to higher requirements for welding consistency and long-term stability, lead-free solder strips are gradually being used.<\/li>\n\n\n\n<li><strong>Lead-free solder strips are more suitable for the development direction of future high-efficiency photovoltaic modules<\/strong>, avoiding welding problems caused by material incompatibility.<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>4. Different options and characteristics of lead-free tin layer<\/strong><\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">\u2705 <strong>Different Types of Lead-Free Tin Plating<\/strong><\/h3>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th><strong>Lead-free solder layer type<\/strong><\/th><th><strong>Main Ingredients<\/strong><\/th><th><strong>Melting point (\u2103)<\/strong><\/th><th><strong>Features<\/strong><\/th><\/tr><\/thead><tbody><tr><td><strong>SN100 (Pure Tin)<\/strong><\/td><td>100% Sn<\/td><td>232\u2103<\/td><td>Environmentally friendly, good wettability, high temperature resistance, suitable for TOPCon components<\/td><\/tr><tr><td><strong>Sn-Ag (Tin-Silver Alloy)<\/strong><\/td><td>Sn+1~3% Ag<\/td><td>221-228\u2103<\/td><td>Improved mechanical strength and welding reliability for high-end components<\/td><\/tr><tr><td><strong>SnBi (Tin-Bismuth Alloy)<\/strong><\/td><td>Sn+Bi<\/td><td>140-170\u2103<\/td><td>Low temperature soldering, suitable for HJT batteries<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\">\u2705 <strong>Application of various lead-free solder strips<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>SN100 (Pure Tin)<\/strong>\uff1aApplicable to TOPCon and PERC components, stable welding and environmentally friendly.<\/li>\n\n\n\n<li><strong>Sn-Ag (Tin-Silver Alloy)<\/strong>\uff1aApplicable to IBC, bifacial N-type batteries, improving thermal fatigue resistance.<\/li>\n\n\n\n<li><strong>SnBi (Tin-Bismuth Alloy)<\/strong>\uff1aUsed for HJT low temperature welding to protect sensitive cells.<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>5. Challenges and future trends of lead-free solder strips<\/strong><\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">\u274c <strong>Challenges of Lead-Free Solder<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>High melting point, higher welding temperature required<\/strong>\n<ul class=\"wp-block-list\">\n<li>SN100 has a melting point of 232\u00b0C, which is higher than SN60PB40 (183-190\u00b0C), requiring more precise temperature-controlled welding equipment.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Slightly higher cost<\/strong>\n<ul class=\"wp-block-list\">\n<li>The silver content of Sn-Ag solder increases the material cost, but in the long run, environmental regulations and the development of photovoltaic technology will gradually reduce the cost.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">\u2705 <strong>Future Trends<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>The popularity of high-efficiency batteries such as HJT and TOPCon will promote the comprehensive application of lead-free solder strips.<\/strong><\/li>\n\n\n\n<li><strong>Lead-free soldering technology is gradually maturing, production costs are decreasing, and it may completely replace lead-containing solder strips in the future.<\/strong><\/li>\n\n\n\n<li><strong>As the carbon neutrality goal is advanced, environmental regulations will become more stringent and lead-free solder strips will become mainstream.<\/strong><\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>Summary: Why choose lead-free solder ribbon?<\/strong><\/h2>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th><strong>reason<\/strong><\/th><th><strong>Detailed description<\/strong><\/th><\/tr><\/thead><tbody><tr><td><strong>Comply with environmental regulations<\/strong><\/td><td>Comply with RoHS &amp; REACH regulations, reduce lead pollution and avoid future compliance risks<\/td><\/tr><tr><td><strong>Improve reliability<\/strong><\/td><td>More durable solder joints, greater crack resistance, and longer thermal cycle life<\/td><\/tr><tr><td><strong>Suitable for new high-efficiency batteries<\/strong><\/td><td>More suitable for high-efficiency photovoltaic technologies such as HJT, TOPCon, and IBC<\/td><\/tr><tr><td><strong>Excellent high temperature resistance<\/strong><\/td><td>Higher melting point, better thermal fatigue resistance, suitable for long-term photovoltaic applications<\/td><\/tr><tr><td><strong>Long-term cost optimization<\/strong><\/td><td>Lead-free solder strips will become the mainstream in the future, avoiding the risk of elimination of lead-containing solder strips<\/td><\/tr><\/tbody><\/table><\/figure>","protected":false},"excerpt":{"rendered":"<p>In recent years, lead-free tin layers (such as SN100, SN-Ag) have been increasingly used in photovoltaic ribbons, mainly due to environmental regulations, new high [\u2026]<\/p>","protected":false},"author":1,"featured_media":9170,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"set","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center 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