{"id":19075,"date":"2026-10-21T14:30:14","date_gmt":"2026-10-21T05:30:14","guid":{"rendered":"https:\/\/www.japanunix.com\/en\/?post_type=column&#038;p=19075"},"modified":"2026-10-23T17:13:16","modified_gmt":"2026-10-23T08:13:16","slug":"steve_solder_spike_causes","status":"publish","type":"column","link":"https:\/\/www.japanunix.com\/en\/column\/steve_solder_spike_causes\/","title":{"rendered":"Solder Spikes in Robotic Soldering: Not Only a Flux Problem [Steve Column]"},"content":{"rendered":"<h3>Table of Contents<\/h3>\n<ul class=\"list-contents\">\n<li><a href=\"#01\">What Is a Solder Spike? &mdash; Solder Drawn Out as the Tip Lifts Off<\/a><\/li>\n<li><a href=\"#02\">Flux&#8217;s Two Roles<\/a><\/li>\n<li><a href=\"#03\">When Flux Deactivates First<\/a><\/li>\n<li><a href=\"#04\">When Heat Doesn&#8217;t Get Through<\/a><\/li>\n<li><a href=\"#05\">Opposite Countermeasures<\/a><\/li>\n<li><a href=\"#06\">Seeing Where and When It Formed<\/a><\/li>\n<li><a href=\"#07\">Summary<\/a><\/li>\n<li><a href=\"#08\">Related Products &amp; Services<\/a><\/li>\n<li><a href=\"#09\">Video for This Tech Article<\/a><\/li>\n<\/ul>\n<hr class=\"hr-color-dark\">\n<div id=\"00\" class=\"c-box\">\n<div class=\"row\">\n<div class=\"col-md-5\">\n<p><a class=\"btn-primary btn-icon-next\" href=\"https:\/\/www.japanunix.com\/en\/products\/automation\/\">Explore Automated Soldering Robots<\/a><\/p>\n<p><a class=\"btn-primary btn-icon-next\" href=\"https:\/\/www.japanunix.com\/en\/products\/laser\/\">Explore Laser Soldering Systems<\/a><\/p>\n<\/div>\n<div class=\"col-md-7\">\n<div class=\"js-modal-video\" data-modal=\"#modal-media-target\" data-video-id=\"zxCR_0KGNUk\">\n<div class=\"_thumb\"><img decoding=\"async\" src=\"https:\/\/img.youtube.com\/vi\/zxCR_0KGNUk\/maxresdefault.jpg\" alt=\"Video for this tech article: Solder Spikes in Automated Soldering: It&#39;s Not Only the Flux\" \/><\/div>\n<\/div>\n<h5>Video for this Tech Article<\/h5>\n<\/div>\n<\/div>\n<\/div>\n<div id=\"01\" class=\"c-box\">\n<div class=\"row\">\n<div class=\"col-md-12\">\n<h2 class=\"heading-title\">What Is a Solder Spike? &mdash; Solder Drawn Out as the Tip Lifts Off<\/h2>\n<\/div>\n<\/div>\n<div class=\"row\">\n<div class=\"col-md-6 order-md-1\">\n<p><span class=\"label-primary\">S<\/span> Hello everyone. I&#8217;m Steve, a soldering engineer at Japan Unix.<\/p>\n<p>Today, I&#8217;ll talk about <strong>solder spikes<\/strong>, also known as icicles, a defect in iron-tip automated soldering.<\/p>\n<\/div>\n<div class=\"col-md-6 order-md-2\">\n<div class=\"_image align-center mb-4\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/www.japanunix.com\/en\/wp\/wp-content\/uploads\/2026\/10\/steve_spike_en_v07_01_title.png\" alt=\"Title screen of the video: Solder Spikes, Not only a flux problem, with Steve introducing himself\" width=\"1200\" height=\"675\"><\/div>\n<\/div>\n<\/div>\n<div class=\"row\">\n<div class=\"col-md-6 order-md-2\">\n<p>A <strong>solder spike is solder drawn out as the tip lifts off, frozen into a projection.<\/strong> Now, let&#8217;s look at how spikes form.<\/p>\n<\/div>\n<div class=\"col-md-6 order-md-1\">\n<div class=\"_image align-center mb-4\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/www.japanunix.com\/en\/wp\/wp-content\/uploads\/2026\/10\/steve_spike_en_v07_02_what_is_it.jpg\" alt=\"A real solder spike on a board: solder drawn out as the tip lifted off and frozen into a projection\" width=\"1200\" height=\"675\"><\/div>\n<\/div>\n<\/div>\n<\/div>\n<div id=\"02\" class=\"c-box\">\n<div class=\"row\">\n<div class=\"col-md-12\">\n<h2 class=\"heading-title\">Flux&#8217;s Two Roles<\/h2>\n<\/div>\n<\/div>\n<div class=\"row\">\n<div class=\"col-md-6 order-md-1\">\n<p><span class=\"label-primary\">S<\/span> Flux plays <strong>two roles<\/strong>: it <strong>removes oxides<\/strong> and <strong>lowers the solder&#8217;s surface tension<\/strong>. With the oxides gone and the tendency to ball up weakened, the solder settles onto the base metal and returns to it even as the tip lifts off.<\/p>\n<\/div>\n<div class=\"col-md-6 order-md-2\">\n<div class=\"_image align-center mb-4\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/www.japanunix.com\/en\/wp\/wp-content\/uploads\/2026\/10\/steve_spike_en_v07_03_flux_two_roles.png\" alt=\"Flux removes oxides and lowers surface tension, so solder settles onto the base metal and returns to it as the tip lifts off\" width=\"1200\" height=\"675\"><\/div>\n<\/div>\n<\/div>\n<\/div>\n<div id=\"03\" class=\"c-box\">\n<div class=\"row\">\n<div class=\"col-md-12\">\n<h2 class=\"heading-title\">When Flux Deactivates First<\/h2>\n<\/div>\n<\/div>\n<div class=\"row\">\n<div class=\"col-md-6 order-md-1\">\n<p><span class=\"label-primary\">S<\/span> But when the <strong>flux is deactivated first<\/strong>, it no longer lowers the surface tension. So the solder freezes while still pulled by the tip.<\/p>\n<\/div>\n<div class=\"col-md-6 order-md-2\">\n<div class=\"_image align-center mb-4\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/www.japanunix.com\/en\/wp\/wp-content\/uploads\/2026\/10\/steve_spike_en_v07_04_flux_deactivated_first.png\" alt=\"When flux deactivates first, surface tension stays high and the solder freezes while still pulled by the tip\" width=\"1200\" height=\"675\"><\/div>\n<\/div>\n<\/div>\n<div class=\"row\">\n<div class=\"col-md-6 order-md-2\">\n<p>Adding solder can make a spike go away, but not necessarily because there&#8217;s more solder. It&#8217;s likely that the <strong>fresh flux coming in with the solder wire<\/strong> is doing the work.<\/p>\n<\/div>\n<div class=\"col-md-6 order-md-1\">\n<div class=\"_image align-center mb-4\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/www.japanunix.com\/en\/wp\/wp-content\/uploads\/2026\/10\/steve_spike_en_v07_05_add_solder.png\" alt=\"Flux deactivated first: surface tension stays high, so solder freezes pulled by the tip. Fresh flux from the wire may help\" width=\"1200\" height=\"675\"><\/div>\n<\/div>\n<\/div>\n<\/div>\n<div id=\"04\" class=\"c-box\">\n<div class=\"row\">\n<div class=\"col-md-12\">\n<h2 class=\"heading-title\">When Heat Doesn&#8217;t Get Through<\/h2>\n<\/div>\n<\/div>\n<div class=\"row\">\n<div class=\"col-md-6 order-md-1\">\n<p><span class=\"label-primary\">S<\/span> On the other hand, <strong>too little heat produces a very similar spike.<\/strong> Without the base metal warming up, the solder doesn&#8217;t flow easily. So it doesn&#8217;t spread down onto the base metal, cools off, and freezes.<\/p>\n<\/div>\n<div class=\"col-md-6 order-md-2\">\n<div class=\"_image align-center mb-4\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/www.japanunix.com\/en\/wp\/wp-content\/uploads\/2026\/10\/steve_spike_en_v07_06_heat_shortage.png\" alt=\"Two causes side by side: flux deactivated first, and base metal not warmed enough. In both, solder freezes without spreading\" width=\"1200\" height=\"675\"><\/div>\n<\/div>\n<\/div>\n<div class=\"row\">\n<div class=\"col-md-6 order-md-2\">\n<p>Both kinds of spike <strong>can occur after production has stabilized.<\/strong> The actual temperature drifting above the setting, the contact time getting longer, or a small amount of solder. These are changes that make the flux more likely to deactivate first. When the tip is misaligned, dirty, or worn, heat transfers less easily, so insufficient heat becomes more likely. The two are hard to tell apart by eye, and flux is suspected first, so <strong>insufficient heat is easy to overlook.<\/strong><\/p>\n<\/div>\n<div class=\"col-md-6 order-md-1\">\n<div class=\"_image align-center mb-4\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/www.japanunix.com\/en\/wp\/wp-content\/uploads\/2026\/10\/steve_spike_en_v07_07_after_stabilized.png\" alt=\"After production stabilizes: changes that make flux deactivate first, and causes of poor heat transfer. Hard to tell by eye\" width=\"1200\" height=\"675\"><\/div>\n<\/div>\n<\/div>\n<\/div>\n<div id=\"05\" class=\"c-box\">\n<div class=\"row\">\n<div class=\"col-md-12\">\n<h2 class=\"heading-title\">Opposite Countermeasures<\/h2>\n<\/div>\n<\/div>\n<div class=\"row\">\n<div class=\"col-md-6 order-md-1\">\n<p><span class=\"label-primary\">S<\/span> What&#8217;s more, <strong>the countermeasures for the two kinds of spike are exact opposites.<\/strong> When the heating time is lengthened to counter insufficient heat, the flux can deactivate, leading to spikes. Conversely, when the time is shortened to suppress spikes, non-wetting can appear instead.<\/p>\n<\/div>\n<div class=\"col-md-6 order-md-2\">\n<div class=\"_image align-center mb-4\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/www.japanunix.com\/en\/wp\/wp-content\/uploads\/2026\/10\/steve_spike_en_v07_08_opposite_countermeasures.png\" alt=\"Opposite countermeasures: a longer heating time can bring spikes, and a shorter time to suppress them can bring non-wetting\" width=\"1200\" height=\"675\"><\/div>\n<\/div>\n<\/div>\n<div class=\"row\">\n<div class=\"col-md-6 order-md-2\">\n<p>In a nitrogen atmosphere, oxidation of the flux is suppressed, so the flux stays active longer. When that condition changes, spikes can increase. When a condition is changed in production, having a record of <strong>what changed, when, and why<\/strong> makes a big difference later.<\/p>\n<\/div>\n<div class=\"col-md-6 order-md-1\">\n<div class=\"_image align-center mb-4\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/www.japanunix.com\/en\/wp\/wp-content\/uploads\/2026\/10\/steve_spike_en_v07_09_nitrogen_and_records.png\" alt=\"Nitrogen keeps flux active longer; if that changes, spikes can increase. Record what, when and why a condition is changed\" width=\"1200\" height=\"675\"><\/div>\n<\/div>\n<\/div>\n<\/div>\n<div id=\"06\" class=\"c-box\">\n<div class=\"row\">\n<div class=\"col-md-12\">\n<h2 class=\"heading-title\">Seeing Where and When It Formed<\/h2>\n<\/div>\n<\/div>\n<div class=\"row\">\n<div class=\"col-md-6 order-md-1\">\n<p><span class=\"label-primary\">S<\/span> Seeing <strong>where and when a spike forms<\/strong>, in real time, gives you more information than the look of the frozen shape. The points to watch: the direction of the projection, the moment it breaks off, the wetting state, and the tip condition. And the fifth is whether you have a record from good runs to compare against.<\/p>\n<\/div>\n<div class=\"col-md-6 order-md-2\">\n<div class=\"_image align-center mb-4\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/www.japanunix.com\/en\/wp\/wp-content\/uploads\/2026\/10\/steve_spike_en_v07_10_checkpoints.jpg\" alt=\"Five points to watch: projection direction, moment it breaks off, wetting state, tip condition, comparison with a good unit\" width=\"1200\" height=\"675\"><\/div>\n<\/div>\n<\/div>\n<p>Neither what I have said so far nor the points below is a procedure for changing anything. Any actual change to a setting, condition, or material is a decision for you to make, under your own change-management procedure (4M change control) and with your own approval.<\/p>\n<ol>\n<li><strong>Direction of the projection<\/strong><\/li>\n<li><strong>The moment it breaks off<\/strong><\/li>\n<li><strong>Wetting state<\/strong><\/li>\n<li><strong>Tip condition<\/strong><\/li>\n<li><strong>Comparison with a good unit<\/strong> &mdash; a record from good runs to compare against<\/li>\n<\/ol>\n<\/div>\n<div id=\"07\" class=\"c-box\">\n<div class=\"row\">\n<div class=\"col-md-12\">\n<h2 class=\"heading-title\">Summary<\/h2>\n<\/div>\n<\/div>\n<div class=\"row\">\n<div class=\"col-md-6 order-md-1\">\n<ul>\n<li>Solder spikes are not only a flux problem<\/li>\n<li>Insufficient heat makes a very similar spike<\/li>\n<li>Look not only at the frozen shape, but at where and when it formed<\/li>\n<\/ul>\n<p><span class=\"label-primary\">S<\/span> Solder spikes are not only a flux problem. Insufficient heat can cause them too. Today was about looking not only at the frozen shape, but at where and when it formed.<\/p>\n<\/div>\n<div class=\"col-md-6 order-md-2\">\n<div class=\"_image align-center mb-4\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/www.japanunix.com\/en\/wp\/wp-content\/uploads\/2026\/10\/steve_spike_en_v07_11_summary.png\" alt=\"Summary: spikes are not only a flux problem; insufficient heat makes a very similar spike; look at where and when it formed\" width=\"1200\" height=\"675\"><\/div>\n<\/div>\n<\/div>\n<\/div>\n<div class=\"panel-light\">\n<div class=\"_header\">Download Now<\/div>\n<div class=\"_body\">\n<div class=\"row\">\n<div class=\"col-md-4\">\n<div class=\"_image align-center mb-4\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/www.japanunix.com\/wp\/wp-content\/uploads\/2026\/09\/fig07_cta_pdf_en.png\" alt=\"Cover illustration of the Soldering Defect Troubleshooting Checklist (PDF document)\" width=\"778\" height=\"1068\"><\/div>\n<\/div>\n<div class=\"col-md-8\">\n<p><mark>When solder spikes appear: what to check before you change anything, in one checklist.<\/mark><\/p>\n<p>The full checklist is in this one PDF. <strong>Soldering Defect Troubleshooting Checklist<\/strong> (2 pages) &mdash; page 1 is the scan-and-check page for the floor, page 2 explains why each point is checked.<\/p>\n<p><a class=\"btn-primary btn-animation btn-block btn-icon-next\" href=\"https:\/\/www.japanunix.com\/en\/contact\/download_catalog#doc_handa\">Download the Soldering Defect Troubleshooting Checklist (Free)<\/a><\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<p>If you have other questions, feel free to reach out to Japan Unix.<\/p>\n<div id=\"08\" class=\"c-box\">\n<div class=\"row\">\n<div class=\"col-md-12\">\n<h2 class=\"heading-title\">Related Products &amp; Services<\/h2>\n<\/div>\n<\/div>\n<\/div>\n<div class=\"c-box\">\n<div class=\"row\">\n<div class=\"col-md-12\">\n<p><a class=\"btn-primary btn-icon-next\" href=\"https:\/\/www.japanunix.com\/en\/products\/automation\/\">Explore Automated Soldering Robots<\/a><\/p>\n<p><a class=\"btn-primary btn-icon-next\" href=\"https:\/\/www.japanunix.com\/en\/products\/laser\/\">Explore Laser Soldering Systems<\/a><\/p>\n<\/div>\n<\/div>\n<\/div>\n<div id=\"09\" class=\"c-box\">\n<div class=\"row\">\n<div class=\"col-md-12\">\n<h2 class=\"heading-title\">Video for This Tech Article<\/h2>\n<\/div>\n<div class=\"col-md-6\">\n<div class=\"js-modal-video\" data-modal=\"#modal-media-target\" data-video-id=\"zxCR_0KGNUk\">\n<div class=\"_thumb\"><img decoding=\"async\" src=\"https:\/\/img.youtube.com\/vi\/zxCR_0KGNUk\/maxresdefault.jpg\" alt=\"Video for this tech article: Solder Spikes in Automated Soldering: It&#39;s Not Only the Flux\" \/><\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<p>Related document: <a href=\"https:\/\/www.japanunix.com\/en\/contact\/download_catalog#doc_handa\">Soldering Defect Troubleshooting Checklist (Free)<\/a><\/p>\n","protected":false},"featured_media":0,"template":"","column_category":[296,307,297],"column_tag":[],"acf":[],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.japanunix.com\/en\/wp-json\/wp\/v2\/column\/19075"}],"collection":[{"href":"https:\/\/www.japanunix.com\/en\/wp-json\/wp\/v2\/column"}],"about":[{"href":"https:\/\/www.japanunix.com\/en\/wp-json\/wp\/v2\/types\/column"}],"wp:attachment":[{"href":"https:\/\/www.japanunix.com\/en\/wp-json\/wp\/v2\/media?parent=19075"}],"wp:term":[{"taxonomy":"column_category","embeddable":true,"href":"https:\/\/www.japanunix.com\/en\/wp-json\/wp\/v2\/column_category?post=19075"},{"taxonomy":"column_tag","embeddable":true,"href":"https:\/\/www.japanunix.com\/en\/wp-json\/wp\/v2\/column_tag?post=19075"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}