{"id":39034,"date":"2026-11-14T17:29:45","date_gmt":"2026-11-14T09:29:45","guid":{"rendered":"https:\/\/www.bestpcbs.com\/blog\/2026\/11\/microvia-glass-fiber-protrusion\/"},"modified":"2026-11-14T17:30:51","modified_gmt":"2026-11-14T09:30:51","slug":"microvia-glass-fiber-protrusion","status":"publish","type":"post","link":"https:\/\/www.bestpcbs.com\/blog\/2026\/11\/microvia-glass-fiber-protrusion\/","title":{"rendered":"Glass Fiber Protrusion in Laser Microvias: What to Inspect"},"content":{"rendered":"<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_89 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\/11\/microvia-glass-fiber-protrusion\/#Laser_drilled_microvias\" >Laser drilled microvias<\/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\/11\/microvia-glass-fiber-protrusion\/#Glass_fiber_protrusion\" >Glass fiber protrusion<\/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\/11\/microvia-glass-fiber-protrusion\/#Laser_microvia_aspect_ratio\" >Laser microvia aspect ratio<\/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\/11\/microvia-glass-fiber-protrusion\/#PCB_desmear_process\" >PCB desmear process<\/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\/11\/microvia-glass-fiber-protrusion\/#Microvia_plating_thickness\" >Microvia plating thickness<\/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\/11\/microvia-glass-fiber-protrusion\/#Microvia_voids\" >Microvia voids<\/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\/11\/microvia-glass-fiber-protrusion\/#PCB_microsection_analysis\" >PCB microsection analysis<\/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\/11\/microvia-glass-fiber-protrusion\/#Microvia_reliability\" >Microvia reliability<\/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\/11\/microvia-glass-fiber-protrusion\/#Frequently_asked_questions\" >Frequently asked questions<\/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\/11\/microvia-glass-fiber-protrusion\/#Technical_references\" >Technical references<\/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\/11\/microvia-glass-fiber-protrusion\/#Discuss_your_HDI_inspection_requirements\" >Discuss your HDI inspection requirements<\/a><\/li><\/ul><\/nav><\/div>\n<div class=\"yzp-no-index\"><\/div><p>If a laser microvia meets the drawing\u2019s opening diameter but plating defects recur, inspect the hole wall before plating. Glass fibers can project into the hole even when its overall dimensions look right. A finished section may show an adjacent void, but it cannot always tell you whether the void started at a rough wall or developed later during metallization.<\/p>\n<p>To separate those causes, compare an as-drilled witness, a witness after cleaning, and a plated section from equivalent features. Record exactly where each section was taken. That sequence gives you a more useful answer than adding a larger drill diameter to the drawing without knowing which process created the defect.<\/p>\n<figure><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/www.bestpcbs.com\/blog\/wp-content\/uploads\/2026\/11\/laser-microvias-inspection-cover.jpg\" alt=\"Small HDI board with closely spaced openings in copper pads\" width=\"1200\" height=\"675\" style=\"display:block;max-width:100%;height:auto\"><figcaption>Illustration of an HDI sample. An overhead view does not establish the shape of the hole wall.<\/figcaption><\/figure>\n<h2><span class=\"ez-toc-section\" id=\"Laser_drilled_microvias\"><\/span>Laser drilled microvias<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>A laser-drilled blind microvia connects an outer or build-up copper layer to a buried target land. The laser removes material to expose the target. In glass-reinforced dielectrics, the resin and glass do not necessarily retreat by the same amount. The top opening, sidewall profile and exposed target are separate inspection surfaces.<\/p>\n<p>For example, suppose a fine-pitch breakout shows repeatable plating defects on one build-up layer but not on a second layer with the same nominal opening. Start by checking which dielectric construction, laser step and cleaning sequence each group actually saw. Identical CAD openings are not evidence that the processed hole walls are identical.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Glass_fiber_protrusion\"><\/span>Glass fiber protrusion<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>A protruding fiber extends from the hole wall into the cavity, beyond the nearby wall profile. It changes the local geometry where the copper layer must form. Measure the extension from the defined local wall boundary, not from the center of the hole or across the entire glass bundle. Record the largest visible value on each sampled wall and the position where it occurs.<\/p>\n<figure class=\"wp-block-table\">\n<table>\n<tbody>\n<tr>\n<td><strong>Parameter<\/strong><\/td>\n<td><strong>What to record<\/strong><\/td>\n<td><strong>Decision it supports<\/strong><\/td>\n<\/tr>\n<tr>\n<td>Opening and base diameters<\/td>\n<td>Both locations, in \u00b5m, at an agreed section plane<\/td>\n<td>Shows the overall hole shape, not local wall defects.<\/td>\n<\/tr>\n<tr>\n<td>Maximum visible projection<\/td>\n<td>Distance in \u00b5m from the local wall to the fiber tip<\/td>\n<td>Flags a local obstruction; document the depth and side.<\/td>\n<\/tr>\n<tr>\n<td>Target-land condition<\/td>\n<td>Visible residue, irregularity or copper damage<\/td>\n<td>Distinguishes a wall issue from a problem at the electrical interface.<\/td>\n<\/tr>\n<tr>\n<td>Process stage<\/td>\n<td>As drilled, after cleaning, or plated<\/td>\n<td>Limits which causes the image can support.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/figure>\n<p>In a hypothetical 100 \u00b5m opening, an 8 \u00b5m projection is 8% of that reference diameter. That calculation describes the observation, not its acceptance. If the inspection plan instead defines a local diameter of 80 \u00b5m at the indicated depth, the same projection is 10% on that basis. State the denominator explicitly. The <a href=\"https:\/\/pmc.ncbi.nlm.nih.gov\/articles\/PMC9182425\/\" rel=\"nofollow\">published drilling study<\/a> separates protrusion, taper and target-copper damage; its research criteria are not a universal production limit.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Laser_microvia_aspect_ratio\"><\/span>Laser microvia aspect ratio<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Aspect ratio describes a relationship between depth and a specified diameter. It does not measure roughness or projecting fibers. A smooth hole and a hole with one projecting bundle can share the same reported depth and entrance diameter. Likewise, an entrance-to-base diameter ratio describes taper, not the maximum projection.<\/p>\n<p>For the example above, keep the depth and both diameters in the report, but do not use their relationship to clear the 8 \u00b5m observation. The approved drawing and inspection plan should state which dimensions and wall observations are required for release. Use the <a href=\"https:\/\/www.bestpcbs.com\/blog\/2026\/11\/microvia-aspect-ratio-depth-diameter\/\">microvia aspect ratio guide<\/a> for the separate dimensional check.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"PCB_desmear_process\"><\/span>PCB desmear process<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Cleaning prepares the drilled surface for metallization. Its purpose and capability depend on the material system and the qualified process. Resin remaining on the target land and glass projecting from the sidewall are different observations. If a change makes the hole look cleaner from above, that does not establish that the sidewall or target is ready.<\/p>\n<p>Compare as-drilled and after-cleaning witnesses from the same construction. If the projection is already present after drilling, review drilling and material interactions before treating cleaning as the only corrective action. If the drilled witness is clean but the cleaned witness reveals a new wall change, investigate the cleaning step and section preparation. Use the agreed process window rather than increasing treatment until one cross-section looks better.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Microvia_plating_thickness\"><\/span>Microvia plating thickness<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Measure copper at the locations identified by the specification and inspection drawing. A surface reading does not establish coverage at the base or around a projecting fiber. The initial conductive layer and the subsequent plating each affect the finished structure. A section should distinguish local coverage, the target interface and the interior of any copper fill.<\/p>\n<p>If the team changes plating without checking the drilled wall, it can improve the average fill while leaving the difficult geometry unchanged. If the wall and base looked sound before plating but an internal void appears afterward, inspect the metallization and fill sequence before changing the laser process.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Microvia_voids\"><\/span>Microvia voids<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>A projecting fiber is a geometric feature of the dielectric wall; a void is a gap seen in the finished metal or at an interface. They may occur together, but one does not prove the other. Use the stage and location of the first observation to select the next check.<\/p>\n<figure class=\"wp-block-table\">\n<table>\n<tbody>\n<tr>\n<td><strong>Observation<\/strong><\/td>\n<td><strong>Best next comparison<\/strong><\/td>\n<td><strong>What it cannot prove<\/strong><\/td>\n<\/tr>\n<tr>\n<td>Fiber projects into an as-drilled wall<\/td>\n<td>Check equivalent features and compare the same layer after cleaning.<\/td>\n<td>It does not establish the size or presence of a plated void.<\/td>\n<\/tr>\n<tr>\n<td>Gap is visible beside the plated wall<\/td>\n<td>Compare unplated witness geometry and check coverage at the corresponding depth.<\/td>\n<td>A single plated section cannot date the first defect.<\/td>\n<\/tr>\n<tr>\n<td>Gap is inside the fill, away from the wall<\/td>\n<td>Compare similar holes across the panel and review the fill process.<\/td>\n<td>Not every fill void is a result of projecting glass.<\/td>\n<\/tr>\n<tr>\n<td>Dark line at the target land<\/td>\n<td>Inspect another section and the target before metallization.<\/td>\n<td>A line alone does not identify contamination, separation or preparation artifact.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/figure>\n<h2><span class=\"ez-toc-section\" id=\"PCB_microsection_analysis\"><\/span>PCB microsection analysis<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Use a section plane that passes through the intended feature center for diameter measurements. If the cut is off center, the apparent opening can be smaller; it can also miss the worst wall region. Request the panel location, layer pair, section orientation and a visible scale bar rather than an isolated cropped picture.<\/p>\n<figure><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/www.bestpcbs.com\/blog\/wp-content\/uploads\/2026\/11\/microsection-inspection-microscope.jpg\" alt=\"Inspection microscope with a mounted specimen on the stage\" width=\"1200\" height=\"675\" style=\"display:block;max-width:100%;height:auto\"><figcaption>Illustration of an inspection setup. Assess the feature using a calibrated section image from the actual sample.<\/figcaption><\/figure>\n<p>When the projection appears on one wall only, take an additional section at the suspected region or inspect further matched witnesses. Include a known-good feature from the same construction. The <a href=\"https:\/\/www.ipc.org\/sites\/default\/files\/test_methods_docs\/2-1-01f.pdf\" rel=\"nofollow\">IPC-TM-650 Method 2.1.1<\/a> describes microsection preparation. Use the specified product acceptance criteria separately; a well-prepared section does not by itself establish conformity.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Microvia_reliability\"><\/span>Microvia reliability<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Release the corrected construction only after confirming that the wall geometry and plated structure both meet the agreed criteria. For rigid boards, check the IPC-6012 revision and class specified on the order, together with the approved drawing and inspection plan. Select coupons or boards representative of the build-up, panel positions and relevant feature sizes. If thermal or interconnect reliability testing is required, use the product\u2019s specified protocol and include the affected layer pair in the test structure.<\/p>\n<p>A room-temperature electrical pass establishes continuity at that moment, not the condition of every wall or its behavior through assembly. After a change, compare the same observation before and after the relevant process shift. Record which manufacturing layer, material and feature were validated; do not automatically extend the result to a different build-up.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Frequently_asked_questions\"><\/span>Frequently asked questions<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<h3>Can the entire microvia be judged from a top-down image?<\/h3>\n<p>No. A top view can be useful for the opening and visible target, but it may hide wall features below the opening. Use a cross-section or another approved inspection method to support claims about the sidewall.<\/p>\n<h3>Does a larger opening necessarily eliminate projecting glass?<\/h3>\n<p>No. A larger opening changes geometry, but material response to the laser and cleaning still matters. Changes also consume routing area. Compare representative witness holes before changing a board drawing.<\/p>\n<h3>Can the same drill qualification cover a glass-free build-up film?<\/h3>\n<p>Do not assume that. A glass-free layer does not have reinforcement bundles projecting into the wall in the same way, but the new material can still have residue, taper or target damage. Verify the new construction on its own terms.<\/p>\n<h3>Is one clean microsection enough to release all layer pairs?<\/h3>\n<p>Not by itself. Layer pairs can differ in dielectric, depth, laser step and plating history. Match sampling to the released construction, the agreed criteria and the risk of the feature.<\/p>\n<h3>Should the drawing specify a fiber projection limit?<\/h3>\n<p>Where it is a release criterion, agree on the measurement stage, method, dimensional reference and limit. Keep the requirement separate from the finished via diameter, and identify the controlling document and revision.<\/p>\n<h3>What should procurement ask for if the first article has a void?<\/h3>\n<p>Ask for the layer pair, panel location, calibrated section and affected lot scope. Request a comparison that separates drilled geometry from plating rather than accepting a disposition based solely on continuity.<\/p>\n<h3>What if the wall feature only appears after polishing?<\/h3>\n<p>Compare another preparation before classifying it as a process defect. Retain images from intermediate stages where available, and ask the lab to account for sectioning and polishing artifacts.<\/p>\n<h3>Can a tighter hole diameter tolerance substitute for a wall check?<\/h3>\n<p>No. It controls the stated dimension. It does not constrain local fiber geometry unless the inspection agreement specifically defines and verifies that feature.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Technical_references\"><\/span>Technical references<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<ul>\n<li><a href=\"https:\/\/pmc.ncbi.nlm.nih.gov\/articles\/PMC9182425\/\" rel=\"nofollow\">Ultrashort Pulsed Laser Drilling of Printed Circuit Board Materials<\/a>: Figure 1 and the accompanying definitions.<\/li>\n<li><a href=\"https:\/\/escies.org\/download\/webDocumentFile%3Fid%3D68305\" rel=\"nofollow\">Microvia Process Guidelines<\/a>: in-process inspection of drilling and target condition.<\/li>\n<\/ul>\n<h2><span class=\"ez-toc-section\" id=\"Discuss_your_HDI_inspection_requirements\"><\/span>Discuss your HDI inspection requirements<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>For a board inquiry, send the stackup, via layer pairs, drawing revision and annotated inspection concern to <a href=\"mailto:sales@bestpcbs.com\">sales@bestpcbs.com<\/a>. Include the applicable acceptance criteria and whether the requested evidence is for the drilled feature, plated feature or both.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>See how to distinguish glass fiber protrusion from plating voids in laser microvias, specify microsection evidence, and verify the correction.<\/p>\n","protected":false},"author":32827,"featured_media":39032,"comment_status":"open","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_uf_show_specific_survey":0,"_uf_disable_surveys":false,"footnotes":""},"categories":[174],"tags":[9389,9390,8260,9391],"class_list":["post-39034","post","type-post","status-publish","format-standard","hentry","category-bestpcb","tag-glass-fiber-protrusion","tag-hdi-microsection","tag-laser-microvias","tag-microvia-plating"],"acf":[],"aioseo_notices":[],"aioseo_head":"\n\t\t<!-- All in One SEO 5.0.4 - aioseo.com -->\n\t<meta name=\"description\" content=\"See how to distinguish glass fiber protrusion from plating voids in laser microvias, specify microsection evidence, and verify the correction.\" \/>\n\t<meta name=\"robots\" content=\"max-image-preview:large\" \/>\n\t<meta name=\"author\" content=\"mingling, gong\"\/>\n\t<link rel=\"canonical\" href=\"https:\/\/www.bestpcbs.com\/blog\/2026\/11\/microvia-glass-fiber-protrusion\/\" \/>\n\t\t<meta name=\"generator\" content=\"All in One SEO (AIOSEO) 5.0.4\" \/>\n\t\t<meta property=\"og:locale\" content=\"en_US\" \/>\n\t\t<meta property=\"og:site_name\" content=\"PCB &amp; MCPCB - EBest PCB - More Technical Details &amp; News on PCB, MCPCB &amp; Ceramic PCB from EBest PCB\" \/>\n\t\t<meta property=\"og:type\" content=\"article\" \/>\n\t\t<meta property=\"og:title\" content=\"Glass Fiber Protrusion in Laser Microvias: What to Inspect\" \/>\n\t\t<meta property=\"og:description\" content=\"See how to distinguish glass fiber protrusion from plating voids in laser microvias, specify microsection evidence, and verify the correction.\" \/>\n\t\t<meta property=\"og:url\" content=\"https:\/\/www.bestpcbs.com\/blog\/2026\/11\/microvia-glass-fiber-protrusion\/\" \/>\n\t\t<meta property=\"og:image\" content=\"https:\/\/www.bestpcbs.com\/blog\/wp-content\/uploads\/2025\/08\/logo.png\" \/>\n\t\t<meta property=\"og:image:secure_url\" content=\"https:\/\/www.bestpcbs.com\/blog\/wp-content\/uploads\/2025\/08\/logo.png\" \/>\n\t\t<meta property=\"article:published_time\" content=\"2026-11-14T09:29:45+00:00\" \/>\n\t\t<meta property=\"article:modified_time\" content=\"2026-11-14T09:30:51+00:00\" \/>\n\t\t<meta property=\"article:publisher\" content=\"https:\/\/www.facebook.com\/Bestpcbs1\" \/>\n\t\t<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n\t\t<meta name=\"twitter:site\" content=\"@bestpcbs\" \/>\n\t\t<meta name=\"twitter:title\" content=\"Glass Fiber Protrusion in Laser Microvias: What to Inspect\" \/>\n\t\t<meta name=\"twitter:description\" content=\"See how to distinguish glass fiber protrusion from plating voids in laser microvias, specify microsection evidence, and verify the correction.\" \/>\n\t\t<meta name=\"twitter:creator\" content=\"@bestpcbs\" \/>\n\t\t<meta name=\"twitter:image\" content=\"https:\/\/www.bestpcbs.com\/blog\/wp-content\/uploads\/2016\/02\/logo.gif\" \/>\n\t\t<script type=\"application\/ld+json\" class=\"aioseo-schema\">\n\t\t\t{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"BlogPosting\",\"@id\":\"https:\\\/\\\/www.bestpcbs.com\\\/blog\\\/2026\\\/11\\\/microvia-glass-fiber-protrusion\\\/#blogposting\",\"name\":\"Glass Fiber Protrusion in Laser Microvias: What to Inspect\",\"headline\":\"Glass Fiber Protrusion in Laser Microvias: What to Inspect\",\"author\":{\"@id\":\"https:\\\/\\\/www.bestpcbs.com\\\/blog\\\/author\\\/gong588\\\/#author\"},\"publisher\":{\"@id\":\"https:\\\/\\\/www.bestpcbs.com\\\/blog\\\/#organization\"},\"image\":{\"@type\":\"ImageObject\",\"url\":\"https:\\\/\\\/www.bestpcbs.com\\\/blog\\\/wp-content\\\/uploads\\\/2026\\\/11\\\/laser-microvias-inspection-cover.jpg\",\"width\":1200,\"height\":675},\"datePublished\":\"2026-11-14T17:29:45+08:00\",\"dateModified\":\"2026-11-14T17:30:51+08:00\",\"inLanguage\":\"en-US\",\"mainEntityOfPage\":{\"@id\":\"https:\\\/\\\/www.bestpcbs.com\\\/blog\\\/2026\\\/11\\\/microvia-glass-fiber-protrusion\\\/#webpage\"},\"isPartOf\":{\"@id\":\"https:\\\/\\\/www.bestpcbs.com\\\/blog\\\/2026\\\/11\\\/microvia-glass-fiber-protrusion\\\/#webpage\"},\"articleSection\":\"bestpcb, glass fiber protrusion, HDI microsection, Laser microvias, microvia plating\"},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\\/\\\/www.bestpcbs.com\\\/blog\\\/2026\\\/11\\\/microvia-glass-fiber-protrusion\\\/#breadcrumblist\",\"itemListElement\":[{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/www.bestpcbs.com\\\/blog\\\/#listItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\\\/\\\/www.bestpcbs.com\\\/blog\\\/\",\"nextItem\":{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/www.bestpcbs.com\\\/blog\\\/category\\\/bestpcb\\\/#listItem\",\"name\":\"bestpcb\"}},{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/www.bestpcbs.com\\\/blog\\\/category\\\/bestpcb\\\/#listItem\",\"position\":2,\"name\":\"bestpcb\",\"item\":\"https:\\\/\\\/www.bestpcbs.com\\\/blog\\\/category\\\/bestpcb\\\/\",\"nextItem\":{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/www.bestpcbs.com\\\/blog\\\/2026\\\/11\\\/microvia-glass-fiber-protrusion\\\/#listItem\",\"name\":\"Glass Fiber Protrusion in Laser Microvias: What to Inspect\"},\"previousItem\":{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/www.bestpcbs.com\\\/blog\\\/#listItem\",\"name\":\"Home\"}},{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/www.bestpcbs.com\\\/blog\\\/2026\\\/11\\\/microvia-glass-fiber-protrusion\\\/#listItem\",\"position\":3,\"name\":\"Glass Fiber Protrusion in Laser Microvias: What to Inspect\",\"previousItem\":{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/www.bestpcbs.com\\\/blog\\\/category\\\/bestpcb\\\/#listItem\",\"name\":\"bestpcb\"}}]},{\"@type\":\"Organization\",\"@id\":\"https:\\\/\\\/www.bestpcbs.com\\\/blog\\\/#organization\",\"name\":\"PCB & MCPCB - Best Technology\",\"description\":\"More Technical Details & News on PCB, MCPCB & Ceramic PCB from EBest PCB\",\"url\":\"https:\\\/\\\/www.bestpcbs.com\\\/blog\\\/\",\"telephone\":\"+8675529091601\",\"logo\":{\"@type\":\"ImageObject\",\"url\":\"https:\\\/\\\/www.bestpcbs.com\\\/blog\\\/wp-content\\\/uploads\\\/2025\\\/08\\\/logo.png\",\"@id\":\"https:\\\/\\\/www.bestpcbs.com\\\/blog\\\/2026\\\/11\\\/microvia-glass-fiber-protrusion\\\/#organizationLogo\"},\"image\":{\"@id\":\"https:\\\/\\\/www.bestpcbs.com\\\/blog\\\/2026\\\/11\\\/microvia-glass-fiber-protrusion\\\/#organizationLogo\"},\"sameAs\":[\"https:\\\/\\\/www.facebook.com\\\/Bestpcbs1\",\"https:\\\/\\\/twitter.com\\\/bestpcbs\",\"https:\\\/\\\/www.youtube.com\\\/channel\\\/UCJsTR02i6mtLFnBBNC_i4bQ\\\/featured\",\"https:\\\/\\\/www.linkedin.com\\\/company\\\/best-pcb-technology\"]},{\"@type\":\"Person\",\"@id\":\"https:\\\/\\\/www.bestpcbs.com\\\/blog\\\/author\\\/gong588\\\/#author\",\"url\":\"https:\\\/\\\/www.bestpcbs.com\\\/blog\\\/author\\\/gong588\\\/\",\"name\":\"mingling, gong\",\"image\":{\"@type\":\"ImageObject\",\"@id\":\"https:\\\/\\\/www.bestpcbs.com\\\/blog\\\/2026\\\/11\\\/microvia-glass-fiber-protrusion\\\/#authorImage\",\"url\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/37717913504b7ea1df97ec73d58a7bcc?s=96&d=mm&r=g\",\"width\":96,\"height\":96,\"caption\":\"mingling, gong\"}},{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/www.bestpcbs.com\\\/blog\\\/2026\\\/11\\\/microvia-glass-fiber-protrusion\\\/#webpage\",\"url\":\"https:\\\/\\\/www.bestpcbs.com\\\/blog\\\/2026\\\/11\\\/microvia-glass-fiber-protrusion\\\/\",\"name\":\"Glass Fiber Protrusion in Laser Microvias: What to Inspect\",\"description\":\"See how to distinguish glass fiber protrusion from plating voids in laser microvias, specify microsection evidence, and verify the correction.\",\"inLanguage\":\"en-US\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/www.bestpcbs.com\\\/blog\\\/#website\"},\"breadcrumb\":{\"@id\":\"https:\\\/\\\/www.bestpcbs.com\\\/blog\\\/2026\\\/11\\\/microvia-glass-fiber-protrusion\\\/#breadcrumblist\"},\"author\":{\"@id\":\"https:\\\/\\\/www.bestpcbs.com\\\/blog\\\/author\\\/gong588\\\/#author\"},\"creator\":{\"@id\":\"https:\\\/\\\/www.bestpcbs.com\\\/blog\\\/author\\\/gong588\\\/#author\"},\"image\":{\"@type\":\"ImageObject\",\"url\":\"https:\\\/\\\/www.bestpcbs.com\\\/blog\\\/wp-content\\\/uploads\\\/2026\\\/11\\\/laser-microvias-inspection-cover.jpg\",\"@id\":\"https:\\\/\\\/www.bestpcbs.com\\\/blog\\\/2026\\\/11\\\/microvia-glass-fiber-protrusion\\\/#mainImage\",\"width\":1200,\"height\":675},\"primaryImageOfPage\":{\"@id\":\"https:\\\/\\\/www.bestpcbs.com\\\/blog\\\/2026\\\/11\\\/microvia-glass-fiber-protrusion\\\/#mainImage\"},\"datePublished\":\"2026-11-14T17:29:45+08:00\",\"dateModified\":\"2026-11-14T17:30:51+08:00\"},{\"@type\":\"WebSite\",\"@id\":\"https:\\\/\\\/www.bestpcbs.com\\\/blog\\\/#website\",\"url\":\"https:\\\/\\\/www.bestpcbs.com\\\/blog\\\/\",\"name\":\"PCB & MCPCB - Best Technology\",\"description\":\"More Technical Details & News on PCB, MCPCB & Ceramic PCB from EBest PCB\",\"inLanguage\":\"en-US\",\"publisher\":{\"@id\":\"https:\\\/\\\/www.bestpcbs.com\\\/blog\\\/#organization\"}}]}\n\t\t<\/script>\n\t\t<!-- All in One SEO -->\n\n","aioseo_head_json":{"title":"Glass Fiber Protrusion in Laser Microvias: What to Inspect","description":"See how to distinguish glass fiber protrusion from plating voids in laser microvias, specify microsection evidence, and verify the correction.","canonical_url":"https:\/\/www.bestpcbs.com\/blog\/2026\/11\/microvia-glass-fiber-protrusion\/","robots":"max-image-preview:large","keywords":"","webmasterTools":{"miscellaneous":""},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"BlogPosting","@id":"https:\/\/www.bestpcbs.com\/blog\/2026\/11\/microvia-glass-fiber-protrusion\/#blogposting","name":"Glass Fiber Protrusion in Laser Microvias: What to Inspect","headline":"Glass Fiber Protrusion in Laser Microvias: What to Inspect","author":{"@id":"https:\/\/www.bestpcbs.com\/blog\/author\/gong588\/#author"},"publisher":{"@id":"https:\/\/www.bestpcbs.com\/blog\/#organization"},"image":{"@type":"ImageObject","url":"https:\/\/www.bestpcbs.com\/blog\/wp-content\/uploads\/2026\/11\/laser-microvias-inspection-cover.jpg","width":1200,"height":675},"datePublished":"2026-11-14T17:29:45+08:00","dateModified":"2026-11-14T17:30:51+08:00","inLanguage":"en-US","mainEntityOfPage":{"@id":"https:\/\/www.bestpcbs.com\/blog\/2026\/11\/microvia-glass-fiber-protrusion\/#webpage"},"isPartOf":{"@id":"https:\/\/www.bestpcbs.com\/blog\/2026\/11\/microvia-glass-fiber-protrusion\/#webpage"},"articleSection":"bestpcb, glass fiber protrusion, HDI microsection, Laser microvias, microvia plating"},{"@type":"BreadcrumbList","@id":"https:\/\/www.bestpcbs.com\/blog\/2026\/11\/microvia-glass-fiber-protrusion\/#breadcrumblist","itemListElement":[{"@type":"ListItem","@id":"https:\/\/www.bestpcbs.com\/blog\/#listItem","position":1,"name":"Home","item":"https:\/\/www.bestpcbs.com\/blog\/","nextItem":{"@type":"ListItem","@id":"https:\/\/www.bestpcbs.com\/blog\/category\/bestpcb\/#listItem","name":"bestpcb"}},{"@type":"ListItem","@id":"https:\/\/www.bestpcbs.com\/blog\/category\/bestpcb\/#listItem","position":2,"name":"bestpcb","item":"https:\/\/www.bestpcbs.com\/blog\/category\/bestpcb\/","nextItem":{"@type":"ListItem","@id":"https:\/\/www.bestpcbs.com\/blog\/2026\/11\/microvia-glass-fiber-protrusion\/#listItem","name":"Glass Fiber Protrusion in Laser Microvias: What to Inspect"},"previousItem":{"@type":"ListItem","@id":"https:\/\/www.bestpcbs.com\/blog\/#listItem","name":"Home"}},{"@type":"ListItem","@id":"https:\/\/www.bestpcbs.com\/blog\/2026\/11\/microvia-glass-fiber-protrusion\/#listItem","position":3,"name":"Glass Fiber Protrusion in Laser Microvias: What to Inspect","previousItem":{"@type":"ListItem","@id":"https:\/\/www.bestpcbs.com\/blog\/category\/bestpcb\/#listItem","name":"bestpcb"}}]},{"@type":"Organization","@id":"https:\/\/www.bestpcbs.com\/blog\/#organization","name":"PCB & MCPCB - Best Technology","description":"More Technical Details & News on PCB, MCPCB & Ceramic PCB from EBest PCB","url":"https:\/\/www.bestpcbs.com\/blog\/","telephone":"+8675529091601","logo":{"@type":"ImageObject","url":"https:\/\/www.bestpcbs.com\/blog\/wp-content\/uploads\/2025\/08\/logo.png","@id":"https:\/\/www.bestpcbs.com\/blog\/2026\/11\/microvia-glass-fiber-protrusion\/#organizationLogo"},"image":{"@id":"https:\/\/www.bestpcbs.com\/blog\/2026\/11\/microvia-glass-fiber-protrusion\/#organizationLogo"},"sameAs":["https:\/\/www.facebook.com\/Bestpcbs1","https:\/\/twitter.com\/bestpcbs","https:\/\/www.youtube.com\/channel\/UCJsTR02i6mtLFnBBNC_i4bQ\/featured","https:\/\/www.linkedin.com\/company\/best-pcb-technology"]},{"@type":"Person","@id":"https:\/\/www.bestpcbs.com\/blog\/author\/gong588\/#author","url":"https:\/\/www.bestpcbs.com\/blog\/author\/gong588\/","name":"mingling, gong","image":{"@type":"ImageObject","@id":"https:\/\/www.bestpcbs.com\/blog\/2026\/11\/microvia-glass-fiber-protrusion\/#authorImage","url":"https:\/\/secure.gravatar.com\/avatar\/37717913504b7ea1df97ec73d58a7bcc?s=96&d=mm&r=g","width":96,"height":96,"caption":"mingling, gong"}},{"@type":"WebPage","@id":"https:\/\/www.bestpcbs.com\/blog\/2026\/11\/microvia-glass-fiber-protrusion\/#webpage","url":"https:\/\/www.bestpcbs.com\/blog\/2026\/11\/microvia-glass-fiber-protrusion\/","name":"Glass Fiber Protrusion in Laser Microvias: What to Inspect","description":"See how to distinguish glass fiber protrusion from plating voids in laser microvias, specify microsection evidence, and verify the correction.","inLanguage":"en-US","isPartOf":{"@id":"https:\/\/www.bestpcbs.com\/blog\/#website"},"breadcrumb":{"@id":"https:\/\/www.bestpcbs.com\/blog\/2026\/11\/microvia-glass-fiber-protrusion\/#breadcrumblist"},"author":{"@id":"https:\/\/www.bestpcbs.com\/blog\/author\/gong588\/#author"},"creator":{"@id":"https:\/\/www.bestpcbs.com\/blog\/author\/gong588\/#author"},"image":{"@type":"ImageObject","url":"https:\/\/www.bestpcbs.com\/blog\/wp-content\/uploads\/2026\/11\/laser-microvias-inspection-cover.jpg","@id":"https:\/\/www.bestpcbs.com\/blog\/2026\/11\/microvia-glass-fiber-protrusion\/#mainImage","width":1200,"height":675},"primaryImageOfPage":{"@id":"https:\/\/www.bestpcbs.com\/blog\/2026\/11\/microvia-glass-fiber-protrusion\/#mainImage"},"datePublished":"2026-11-14T17:29:45+08:00","dateModified":"2026-11-14T17:30:51+08:00"},{"@type":"WebSite","@id":"https:\/\/www.bestpcbs.com\/blog\/#website","url":"https:\/\/www.bestpcbs.com\/blog\/","name":"PCB & MCPCB - Best Technology","description":"More Technical Details & News on PCB, MCPCB & Ceramic PCB from EBest PCB","inLanguage":"en-US","publisher":{"@id":"https:\/\/www.bestpcbs.com\/blog\/#organization"}}]},"og:locale":"en_US","og:site_name":"PCB &amp; MCPCB - EBest PCB - More Technical Details &amp; News on PCB, MCPCB &amp; Ceramic PCB from EBest PCB","og:type":"article","og:title":"Glass Fiber Protrusion in Laser Microvias: What to Inspect","og:description":"See how to distinguish glass fiber protrusion from plating voids in laser microvias, specify microsection evidence, and verify the correction.","og:url":"https:\/\/www.bestpcbs.com\/blog\/2026\/11\/microvia-glass-fiber-protrusion\/","og:image":"https:\/\/www.bestpcbs.com\/blog\/wp-content\/uploads\/2025\/08\/logo.png","og:image:secure_url":"https:\/\/www.bestpcbs.com\/blog\/wp-content\/uploads\/2025\/08\/logo.png","article:published_time":"2026-11-14T09:29:45+00:00","article:modified_time":"2026-11-14T09:30:51+00:00","article:publisher":"https:\/\/www.facebook.com\/Bestpcbs1","twitter:card":"summary_large_image","twitter:site":"@bestpcbs","twitter:title":"Glass Fiber Protrusion in Laser Microvias: What to Inspect","twitter:description":"See how to distinguish glass fiber protrusion from plating voids in laser microvias, specify microsection evidence, and verify the correction.","twitter:creator":"@bestpcbs","twitter:image":"https:\/\/www.bestpcbs.com\/blog\/wp-content\/uploads\/2016\/02\/logo.gif"},"aioseo_meta_data":{"post_id":"39034","title":"Glass Fiber Protrusion in Laser Microvias: What to Inspect","description":"See how to distinguish glass fiber protrusion from plating voids in laser microvias, specify microsection evidence, and verify the correction.","keywords":null,"keyphrases":null,"primary_term":null,"canonical_url":null,"og_title":null,"og_description":null,"og_object_type":"default","og_image_type":"default","og_image_url":null,"og_image_width":null,"og_image_height":null,"og_image_custom_url":null,"og_image_custom_fields":null,"og_video":"","og_custom_url":null,"og_article_section":null,"og_article_tags":null,"twitter_use_og":false,"twitter_card":"default","twitter_image_type":"default","twitter_image_url":null,"twitter_image_custom_url":null,"twitter_image_custom_fields":null,"twitter_title":null,"twitter_description":null,"schema":{"blockGraphs":[],"customGraphs":[],"default":{"data":{"Article":[],"Course":[],"Dataset":[],"FAQPage":[],"Movie":[],"Person":[],"Product":[],"ProductReview":[],"Car":[],"Recipe":[],"Service":[],"SoftwareApplication":[],"WebPage":[]},"graphName":"","isEnabled":true},"graphs":[]},"schema_type":"default","schema_type_options":null,"pillar_content":false,"robots_default":true,"robots_noindex":false,"robots_noarchive":false,"robots_nosnippet":false,"robots_nofollow":false,"robots_noimageindex":false,"robots_noodp":false,"robots_notranslate":false,"robots_max_snippet":null,"robots_max_videopreview":null,"robots_max_imagepreview":"large","priority":0,"frequency":"default","local_seo":null,"breadcrumb_settings":null,"limit_modified_date":false,"ai":null,"created":"2026-11-14 09:29:46","updated":"2026-11-14 10:31:52","seo_analyzer_scan_date":null,"focus_keyword":null,"additional_keywords":null,"truseo_locale":null},"aioseo_breadcrumb":"<div class=\"aioseo-breadcrumbs\"><span class=\"aioseo-breadcrumb\">\n\t\t\t<a href=\"https:\/\/www.bestpcbs.com\/blog\/\" title=\"Home\">Home<\/a>\n\t\t<\/span><span class=\"aioseo-breadcrumb-separator\">\u00bb<\/span><span class=\"aioseo-breadcrumb\">\n\t\t\t<a href=\"https:\/\/www.bestpcbs.com\/blog\/category\/bestpcb\/\" title=\"bestpcb\">bestpcb<\/a>\n\t\t<\/span><span class=\"aioseo-breadcrumb-separator\">\u00bb<\/span><span class=\"aioseo-breadcrumb\">\n\t\t\tGlass Fiber Protrusion in Laser Microvias: What to Inspect\n\t\t<\/span><\/div>","aioseo_breadcrumb_json":[{"label":"Home","link":"https:\/\/www.bestpcbs.com\/blog\/"},{"label":"bestpcb","link":"https:\/\/www.bestpcbs.com\/blog\/category\/bestpcb\/"},{"label":"Glass Fiber Protrusion in Laser Microvias: What to Inspect","link":"https:\/\/www.bestpcbs.com\/blog\/2026\/11\/microvia-glass-fiber-protrusion\/"}],"_links":{"self":[{"href":"https:\/\/www.bestpcbs.com\/blog\/wp-json\/wp\/v2\/posts\/39034","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\/32827"}],"replies":[{"embeddable":true,"href":"https:\/\/www.bestpcbs.com\/blog\/wp-json\/wp\/v2\/comments?post=39034"}],"version-history":[{"count":1,"href":"https:\/\/www.bestpcbs.com\/blog\/wp-json\/wp\/v2\/posts\/39034\/revisions"}],"predecessor-version":[{"id":39035,"href":"https:\/\/www.bestpcbs.com\/blog\/wp-json\/wp\/v2\/posts\/39034\/revisions\/39035"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.bestpcbs.com\/blog\/wp-json\/wp\/v2\/media\/39032"}],"wp:attachment":[{"href":"https:\/\/www.bestpcbs.com\/blog\/wp-json\/wp\/v2\/media?parent=39034"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bestpcbs.com\/blog\/wp-json\/wp\/v2\/categories?post=39034"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bestpcbs.com\/blog\/wp-json\/wp\/v2\/tags?post=39034"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}