{"id":31061,"date":"2026-07-16T17:23:55","date_gmt":"2026-07-16T09:23:55","guid":{"rendered":"https:\/\/www.bestpcbs.com\/blog\/?p=31061"},"modified":"2026-07-16T17:25:14","modified_gmt":"2026-07-16T09:25:14","slug":"pcb-backdrill","status":"publish","type":"post","link":"https:\/\/www.bestpcbs.com\/blog\/2026\/07\/pcb-backdrill\/","title":{"rendered":"PCB Backdrill Guide\u2014Process, Stub Length, Cost, and Blind Via Comparison"},"content":{"rendered":"<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_84 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\/07\/pcb-backdrill\/#What_Is_PCB_Backdrill\" >What Is PCB Backdrill?<\/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\/07\/pcb-backdrill\/#What_Is_a_PCB_Via_Stub\" >What Is a PCB Via Stub?<\/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\/07\/pcb-backdrill\/#Why_Does_PCB_Backdrilling_Improve_Signal_Integrity\" >Why Does PCB Backdrilling Improve Signal Integrity?<\/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\/07\/pcb-backdrill\/#When_Is_PCB_Backdrilling_Required\" >When Is PCB Backdrilling Required?<\/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\/07\/pcb-backdrill\/#How_Does_the_PCB_Backdrill_Process_Work\" >How Does the PCB Backdrill Process Work?<\/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\/07\/pcb-backdrill\/#What_Is_an_Acceptable_Backdrill_Stub_Length\" >What Is an Acceptable Backdrill Stub Length?<\/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\/07\/pcb-backdrill\/#What_Are_the_Main_PCB_Backdrill_Design_Rules\" >What Are the Main PCB Backdrill Design Rules?<\/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\/07\/pcb-backdrill\/#Can_a_PCB_Be_Backdrilled_From_Both_Sides\" >Can a PCB Be Backdrilled From Both Sides?<\/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\/07\/pcb-backdrill\/#PCB_Backdrill_vs_Blind_Via_What_Is_the_Difference\" >PCB Backdrill vs Blind Via: What Is the Difference?<\/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\/07\/pcb-backdrill\/#What_Factors_Affect_PCB_Backdrill_Cost\" >What Factors Affect PCB Backdrill Cost?<\/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\/07\/pcb-backdrill\/#What_Files_Are_Required_for_PCB_Backdrilling\" >What Files Are Required for PCB Backdrilling?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-12\" href=\"https:\/\/www.bestpcbs.com\/blog\/2026\/07\/pcb-backdrill\/#How_Is_PCB_Backdrill_Quality_Inspected\" >How Is PCB Backdrill Quality Inspected?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-13\" href=\"https:\/\/www.bestpcbs.com\/blog\/2026\/07\/pcb-backdrill\/#What_Are_Common_PCB_Backdrill_Defects\" >What Are Common PCB Backdrill Defects?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-14\" href=\"https:\/\/www.bestpcbs.com\/blog\/2026\/07\/pcb-backdrill\/#What_Applications_Commonly_Use_PCB_Backdrilling\" >What Applications Commonly Use PCB Backdrilling?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-15\" href=\"https:\/\/www.bestpcbs.com\/blog\/2026\/07\/pcb-backdrill\/#How_to_Prepare_a_PCB_Backdrill_Project_for_Manufacturing\" >How to Prepare a PCB Backdrill Project for Manufacturing<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-16\" href=\"https:\/\/www.bestpcbs.com\/blog\/2026\/07\/pcb-backdrill\/#FAQs\" >FAQs<\/a><\/li><\/ul><\/nav><\/div>\n<div class=\"yzp-no-index\"><\/div><div class=\"content-wrap\">\n<div style=\"width: 100%; max-width: 600px; margin: 24px auto; overflow: hidden; box-sizing: border-box;\"><img decoding=\"async\" style=\"display: block; width: 100%; max-width: 600px; max-height: 400px; height: auto; object-fit: contain; margin: 0 auto; box-sizing: border-box; border-radius: 8px;\" src=\"https:\/\/www.bestpcbs.com\/blog\/wp-content\/uploads\/2026\/07\/pcb-backdrill.jpg\" alt=\"PCB backdrill comparison showing an unused via stub and a backdrilled via\" data-first-enter-image=\"true\" \/><\/div>\n<p style=\"margin: 0 0 17px; line-height: 1.72;\">PCB backdrill is a controlled-depth drilling process that removes the unused copper barrel of a plated through-hole. It is mainly used on thick, high-layer-count PCBs carrying fast digital signals.<\/p>\n<p style=\"margin: 0 0 17px; line-height: 1.72;\">The process can improve channel performance, but it also adds drill programs, inspection work, and fabrication cost. The decision should be based on actual via geometry and signal-integrity results rather than data rate alone.<\/p>\n<h2 style=\"font-size: 29px; line-height: 1.28; color: #162d4d;\"><span class=\"ez-toc-section\" id=\"What_Is_PCB_Backdrill\"><\/span>What Is PCB Backdrill?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p style=\"margin: 0 0 17px; line-height: 1.72;\">PCB backdrill, also called controlled-depth drilling, removes the unused plated section of a through-hole via. The manufacturer first drills and plates the complete hole. A second, slightly larger drill then enters from the specified side and stops near the final connected layer.<\/p>\n<p style=\"margin: 0 0 17px; line-height: 1.72;\">Backdrilling is normally limited to electrically sensitive structures such as:<\/p>\n<ul style=\"margin: 10px 0 22px; padding-left: 25px;\">\n<li style=\"margin: 7px 0;\">High-speed signal vias<\/li>\n<li style=\"margin: 7px 0;\">Press-fit connector holes<\/li>\n<li style=\"margin: 7px 0;\">Backplane connector pins<\/li>\n<li style=\"margin: 7px 0;\">Differential-pair transitions<\/li>\n<li style=\"margin: 7px 0;\">Clock and serial-data connections<\/li>\n<\/ul>\n<h2 style=\"font-size: 29px; line-height: 1.28; color: #162d4d;\"><span class=\"ez-toc-section\" id=\"What_Is_a_PCB_Via_Stub\"><\/span>What Is a PCB Via Stub?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p style=\"margin: 0 0 17px; line-height: 1.72;\">A PCB via stub is the unused part of a plated via barrel extending beyond the last layer connected to the signal. For example, when a signal travels from L1 to L5 through a plated through-hole on a 14-layer PCB, the barrel between L6 and L14 remains electrically attached but performs no routing function.<\/p>\n<p style=\"margin: 0 0 17px; line-height: 1.72;\">The stub acts like an open transmission-line branch. It becomes more troublesome when the board is thick, the transition ends near an outer layer, the signal edge is fast, or the unused barrel is long.<\/p>\n<h2 style=\"font-size: 29px; line-height: 1.28; color: #162d4d;\"><span class=\"ez-toc-section\" id=\"Why_Does_PCB_Backdrilling_Improve_Signal_Integrity\"><\/span>Why Does PCB Backdrilling Improve Signal Integrity?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p style=\"margin: 0 0 17px; line-height: 1.72;\">Backdrilling shortens the unused conductive branch attached to the active via. A long stub can create a resonant notch, worsen the via impedance discontinuity, and consume channel margin.<\/p>\n<ul style=\"margin: 10px 0 22px; padding-left: 25px;\">\n<li style=\"margin: 7px 0;\">Lower signal reflection<\/li>\n<li style=\"margin: 7px 0;\">Reduced insertion-loss notches<\/li>\n<li style=\"margin: 7px 0;\">Better return loss<\/li>\n<li style=\"margin: 7px 0;\">Wider and cleaner eye diagrams<\/li>\n<li style=\"margin: 7px 0;\">Less deterministic jitter<\/li>\n<li style=\"margin: 7px 0;\">Lower bit-error risk<\/li>\n<\/ul>\n<div style=\"width: 100%; max-width: 600px; margin: 24px auto; overflow: hidden; box-sizing: border-box;\"><img decoding=\"async\" style=\"display: block; width: 100%; max-width: 600px; max-height: 400px; height: auto; object-fit: contain; margin: 0 auto; box-sizing: border-box; border-radius: 8px;\" src=\"https:\/\/www.bestpcbs.com\/blog\/wp-content\/uploads\/2026\/07\/pcb-backdrill-signal-integrity.jpg\" alt=\"Comparison of signal reflection from a long via stub and a cleaner backdrilled signal\" \/><\/div>\n<p style=\"margin: 0 0 17px; line-height: 1.72;\">Backdrilling does not remove every via discontinuity. Pads, antipads, the functional barrel, and reference-plane transitions still require careful design.<\/p>\n<h2 style=\"font-size: 29px; line-height: 1.28; color: #162d4d;\"><span class=\"ez-toc-section\" id=\"When_Is_PCB_Backdrilling_Required\"><\/span>When Is PCB Backdrilling Required?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p style=\"margin: 0 0 17px; line-height: 1.72;\">PCB backdrilling is justified when the unused barrel creates a measurable channel problem and its removal provides enough performance benefit to cover the added manufacturing work.<\/p>\n<p style=\"margin: 0 0 17px; line-height: 1.72;\">Evaluate it when the design has:<\/p>\n<ul style=\"margin: 10px 0 22px; padding-left: 25px;\">\n<li style=\"margin: 7px 0;\">Outer-layer signals connecting to shallow inner layers<\/li>\n<li style=\"margin: 7px 0;\">A thick PCB with long vertical interconnects<\/li>\n<li style=\"margin: 7px 0;\">High-speed press-fit connectors<\/li>\n<li style=\"margin: 7px 0;\">Tight insertion-loss or return-loss limits<\/li>\n<li style=\"margin: 7px 0;\">Eye-diagram or simulation failures linked to via resonance<\/li>\n<li style=\"margin: 7px 0;\">Blind-via alternatives that would require sequential lamination<\/li>\n<\/ul>\n<p style=\"margin: 0 0 17px; line-height: 1.72;\">It may be unnecessary when the signal uses most of the barrel, the board is thin, the remaining stub is already short, or a routing-layer change solves the issue.<\/p>\n<h2 style=\"font-size: 29px; line-height: 1.28; color: #162d4d;\"><span class=\"ez-toc-section\" id=\"How_Does_the_PCB_Backdrill_Process_Work\"><\/span>How Does the PCB Backdrill Process Work?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p style=\"margin: 0 0 17px; line-height: 1.72;\">The operation is added after the original through-holes have been drilled and plated.<\/p>\n<div style=\"width: 100%; overflow-x: auto; -webkit-overflow-scrolling: touch;\">\n<table style=\"border-collapse: collapse; width: 100%; min-width: 640px; margin: 20px 0 25px; font-size: 15px;\">\n<thead>\n<tr>\n<th style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left; background: #edf3f8; color: #142a43;\">Stage<\/th>\n<th style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left; background: #edf3f8; color: #142a43;\">Main operation<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Engineering review<\/td>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Confirm stackup, hole locations, drill direction, and stop layers.<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Primary drilling<\/td>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Drill the original plated through-holes.<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Hole plating<\/td>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Plate copper through the complete barrel.<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Backdrill setup<\/td>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Select a larger tool and program each controlled depth.<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Controlled drilling<\/td>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Remove the unused plated barrel from the specified side.<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Inspection<\/td>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Verify depth, residual stub, and electrical continuity.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<div style=\"width: 100%; max-width: 600px; margin: 24px auto; overflow: hidden; box-sizing: border-box;\"><img decoding=\"async\" style=\"display: block; width: 100%; max-width: 600px; max-height: 400px; height: auto; object-fit: contain; margin: 0 auto; box-sizing: border-box; border-radius: 8px;\" src=\"https:\/\/www.bestpcbs.com\/blog\/wp-content\/uploads\/2026\/07\/pcb-backdrill-process.jpg\" alt=\"PCB backdrill process from primary drilling and plating to controlled-depth drilling\" \/><\/div>\n<p style=\"margin: 0 0 17px; line-height: 1.72;\">Different connection depths usually require separate programs. The final stackup must therefore be confirmed before the manufacturer calculates drill depth.<\/p>\n<h2 style=\"font-size: 29px; line-height: 1.28; color: #162d4d;\"><span class=\"ez-toc-section\" id=\"What_Is_an_Acceptable_Backdrill_Stub_Length\"><\/span>What Is an Acceptable Backdrill Stub Length?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p style=\"margin: 0 0 17px; line-height: 1.72;\">The acceptable residual stub must satisfy the electrical target while leaving enough depth margin to protect the final connected layer. Around <strong>10 mils, or 0.25 mm<\/strong>, is a common starting point, although the correct value depends on the channel and the fabricator\u2019s depth-control capability.<\/p>\n<p style=\"margin: 0 0 17px; line-height: 1.72;\">The limit is influenced by:<\/p>\n<ul style=\"margin: 10px 0 22px; padding-left: 25px;\">\n<li style=\"margin: 7px 0;\">Signal bandwidth and edge rate<\/li>\n<li style=\"margin: 7px 0;\">Laminate dielectric properties<\/li>\n<li style=\"margin: 7px 0;\">Board thickness and layer spacing<\/li>\n<li style=\"margin: 7px 0;\">Via drill and pad geometry<\/li>\n<li style=\"margin: 7px 0;\">Lamination thickness variation<\/li>\n<li style=\"margin: 7px 0;\">Backdrill depth tolerance<\/li>\n<\/ul>\n<p style=\"margin: 0 0 17px; line-height: 1.72;\">An unnecessarily short target increases the risk of cutting the connected pad and may add microsection, process-control, and yield costs.<\/p>\n<h2 style=\"font-size: 29px; line-height: 1.28; color: #162d4d;\"><span class=\"ez-toc-section\" id=\"What_Are_the_Main_PCB_Backdrill_Design_Rules\"><\/span>What Are the Main PCB Backdrill Design Rules?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p style=\"margin: 0 0 17px; line-height: 1.72;\">The larger secondary drill needs enough clearance from nearby traces, planes, pads, and adjacent holes.<\/p>\n<div style=\"width: 100%; overflow-x: auto; -webkit-overflow-scrolling: touch;\">\n<table style=\"border-collapse: collapse; width: 100%; min-width: 640px; margin: 20px 0 25px; font-size: 15px;\">\n<thead>\n<tr>\n<th style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left; background: #edf3f8; color: #142a43;\">Design item<\/th>\n<th style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left; background: #edf3f8; color: #142a43;\">Practical guidance<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Drill direction<\/td>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">State top, bottom, or both sides.<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Start and stop layers<\/td>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Use consistent layer names and numbers.<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Residual stub<\/td>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Define the maximum finished stub length.<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Backdrill diameter<\/td>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Use a tool larger than the primary drill; a 0.15\u20130.25 mm increase is a common early-design reference.<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Copper clearance<\/td>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Base clearance on the larger backdrill tool and registration tolerance.<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Non-functional pads<\/td>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Remove them where they restrict the drilling envelope.<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Depth groups<\/td>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Reduce the number of unique depths where routing permits.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<div style=\"width: 100%; max-width: 600px; margin: 24px auto; overflow: hidden; box-sizing: border-box;\"><img decoding=\"async\" style=\"display: block; width: 100%; max-width: 600px; max-height: 400px; height: auto; object-fit: contain; margin: 0 auto; box-sizing: border-box; border-radius: 8px;\" src=\"https:\/\/www.bestpcbs.com\/blog\/wp-content\/uploads\/2026\/07\/pcb-backdrill-design-rules.jpg\" alt=\"PCB backdrill design rules showing drill diameter, stop layer, and residual stub length\" \/><\/div>\n<p style=\"margin: 0 0 17px; line-height: 1.72;\">Use these values only for early planning. Final drill sizes, copper clearances, and tolerances must match the selected factory\u2019s process capability.<\/p>\n<h2 style=\"font-size: 29px; line-height: 1.28; color: #162d4d;\"><span class=\"ez-toc-section\" id=\"Can_a_PCB_Be_Backdrilled_From_Both_Sides\"><\/span>Can a PCB Be Backdrilled From Both Sides?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p style=\"margin: 0 0 17px; line-height: 1.72;\">Yes. Top-side drilling removes an unused barrel above the active connection, while bottom-side drilling removes the section below it. A via connecting two internal layers may require drilling from both sides.<\/p>\n<p style=\"margin: 0 0 17px; line-height: 1.72;\">Double-sided processing can add:<\/p>\n<ul style=\"margin: 10px 0 22px; padding-left: 25px;\">\n<li style=\"margin: 7px 0;\">Separate top and bottom NC files<\/li>\n<li style=\"margin: 7px 0;\">More depth groups<\/li>\n<li style=\"margin: 7px 0;\">Additional panel handling<\/li>\n<li style=\"margin: 7px 0;\">Greater alignment and documentation risk<\/li>\n<li style=\"margin: 7px 0;\">More inspection and setup cost<\/li>\n<\/ul>\n<p style=\"margin: 0 0 17px; line-height: 1.72;\">The fabrication drawing must identify the drilling side and stop layer for every hole group.<\/p>\n<h2 style=\"font-size: 29px; line-height: 1.28; color: #162d4d;\"><span class=\"ez-toc-section\" id=\"PCB_Backdrill_vs_Blind_Via_What_Is_the_Difference\"><\/span>PCB Backdrill vs Blind Via: What Is the Difference?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p style=\"margin: 0 0 17px; line-height: 1.72;\">Backdrilling is mainly used to improve the electrical performance of a conventional through-hole. Blind vias create partial-depth connections and can also improve routing density.<\/p>\n<div style=\"width: 100%; overflow-x: auto; -webkit-overflow-scrolling: touch;\">\n<table style=\"border-collapse: collapse; width: 100%; min-width: 640px; margin: 20px 0 25px; font-size: 15px;\">\n<thead>\n<tr>\n<th style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left; background: #edf3f8; color: #142a43;\">Comparison<\/th>\n<th style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left; background: #edf3f8; color: #142a43;\">PCB backdrill<\/th>\n<th style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left; background: #edf3f8; color: #142a43;\">Blind via<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Basic structure<\/td>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Plated through-hole with part of the barrel removed<\/td>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Via connects an outer layer to an inner layer<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Main purpose<\/td>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Reduce the unused via stub<\/td>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Create a partial-layer connection<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Residual stub<\/td>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">A short stub normally remains<\/td>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">No unused through-board barrel<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Routing density<\/td>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Similar footprint to a through-hole<\/td>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Can release routing space on deeper layers<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Stackup impact<\/td>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Often uses a conventional multilayer build<\/td>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">May require sequential lamination<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Cost driver<\/td>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Hole quantity, depth groups, direction, and inspection<\/td>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Via structure, plating, and lamination cycles<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<div style=\"width: 100%; max-width: 600px; margin: 24px auto; overflow: hidden; box-sizing: border-box;\"><img decoding=\"async\" style=\"display: block; width: 100%; max-width: 600px; max-height: 400px; height: auto; object-fit: contain; margin: 0 auto; box-sizing: border-box; border-radius: 8px;\" src=\"https:\/\/www.bestpcbs.com\/blog\/wp-content\/uploads\/2026\/07\/pcb-backdrill-vs-blind-via.jpg\" alt=\"PCB backdrill versus blind via structure and manufacturing comparison\" \/><\/div>\n<p style=\"margin: 0 0 17px; line-height: 1.72;\">Backdrilling can be more economical when blind vias would add lamination cycles. Blind vias remain attractive when HDI routing density is the main constraint.<\/p>\n<h2 style=\"font-size: 29px; line-height: 1.28; color: #162d4d;\"><span class=\"ez-toc-section\" id=\"What_Factors_Affect_PCB_Backdrill_Cost\"><\/span>What Factors Affect PCB Backdrill Cost?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p style=\"margin: 0 0 17px; line-height: 1.72;\">PCB backdrill cost is based on process complexity rather than a fixed price per hole.<\/p>\n<ul style=\"margin: 10px 0 22px; padding-left: 25px;\">\n<li style=\"margin: 7px 0;\"><strong>Hole quantity:<\/strong> More holes increase drill time and tool wear.<\/li>\n<li style=\"margin: 7px 0;\"><strong>Depth groups:<\/strong> Each unique layer pair may require another setup.<\/li>\n<li style=\"margin: 7px 0;\"><strong>Drilling direction:<\/strong> Two-sided processing adds handling and alignment work.<\/li>\n<li style=\"margin: 7px 0;\"><strong>Stub tolerance:<\/strong> Shorter residual stubs require tighter depth control.<\/li>\n<li style=\"margin: 7px 0;\"><strong>Board construction:<\/strong> Thickness, layer count, hole size, and material affect machinability.<\/li>\n<li style=\"margin: 7px 0;\"><strong>Inspection:<\/strong> Coupons, microsections, TDR, and reports add cost.<\/li>\n<li style=\"margin: 7px 0;\"><strong>Order quantity:<\/strong> Prototype setup costs are spread across fewer boards.<\/li>\n<\/ul>\n<p style=\"margin: 0 0 17px; line-height: 1.72;\">Grouping signals around fewer transition depths can reduce both setup cost and CAM complexity.<\/p>\n<h2 style=\"font-size: 29px; line-height: 1.28; color: #162d4d;\"><span class=\"ez-toc-section\" id=\"What_Files_Are_Required_for_PCB_Backdrilling\"><\/span>What Files Are Required for PCB Backdrilling?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p style=\"margin: 0 0 17px; line-height: 1.72;\">A useful quotation package must identify the exact holes, drilling direction, final diameter, layer range, and residual stub limit.<\/p>\n<ul style=\"margin: 10px 0 22px; padding-left: 25px;\">\n<li style=\"margin: 7px 0;\">Gerber, Gerber X2, IPC-2581, or ODB++ data<\/li>\n<li style=\"margin: 7px 0;\">Primary plated-hole NC drill file<\/li>\n<li style=\"margin: 7px 0;\">Separate backdrill NC files for each depth and side<\/li>\n<li style=\"margin: 7px 0;\">Final PCB stackup<\/li>\n<li style=\"margin: 7px 0;\">Fabrication drawing and drill table<\/li>\n<li style=\"margin: 7px 0;\">Start and stop layers<\/li>\n<li style=\"margin: 7px 0;\">Backdrill direction and final tool diameter<\/li>\n<li style=\"margin: 7px 0;\">Maximum residual stub<\/li>\n<li style=\"margin: 7px 0;\">Controlled-impedance information<\/li>\n<li style=\"margin: 7px 0;\">Coupon, microsection, and reporting requirements<\/li>\n<\/ul>\n<p style=\"margin: 0 0 17px; line-height: 1.72;\">Keep layer naming consistent across every file. Mixed layer labels are a common source of CAM interpretation errors.<\/p>\n<h2 style=\"font-size: 29px; line-height: 1.28; color: #162d4d;\"><span class=\"ez-toc-section\" id=\"How_Is_PCB_Backdrill_Quality_Inspected\"><\/span>How Is PCB Backdrill Quality Inspected?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p style=\"margin: 0 0 17px; line-height: 1.72;\">Inspection confirms that the unused copper has been removed without damaging the intended connection.<\/p>\n<ul style=\"margin: 10px 0 22px; padding-left: 25px;\">\n<li style=\"margin: 7px 0;\"><strong>Machine calibration:<\/strong> Confirms the programmed depth before panel drilling.<\/li>\n<li style=\"margin: 7px 0;\"><strong>Backdrill coupon:<\/strong> Reproduces the critical structure outside the functional board.<\/li>\n<li style=\"margin: 7px 0;\"><strong>Microsection:<\/strong> Measures the actual stub and clearance to the target layer.<\/li>\n<li style=\"margin: 7px 0;\"><strong>Optical inspection:<\/strong> Checks burrs, debris, and visible misregistration.<\/li>\n<li style=\"margin: 7px 0;\"><strong>Electrical testing:<\/strong> Detects opens and shorts.<\/li>\n<li style=\"margin: 7px 0;\"><strong>TDR or impedance testing:<\/strong> Verifies electrical behavior when specified.<\/li>\n<\/ul>\n<div style=\"width: 100%; max-width: 600px; margin: 24px auto; overflow: hidden; box-sizing: border-box;\"><img decoding=\"async\" style=\"display: block; width: 100%; max-width: 600px; max-height: 400px; height: auto; object-fit: contain; margin: 0 auto; box-sizing: border-box; border-radius: 8px;\" src=\"https:\/\/www.bestpcbs.com\/blog\/wp-content\/uploads\/2026\/07\/pcb-backdrill-inspection.jpg\" alt=\"PCB backdrill stackup review, NC drill control, microsection, and inspection workflow\" \/><\/div>\n<p style=\"margin: 0 0 17px; line-height: 1.72;\">Inspection requirements should be agreed during quotation so that suitable coupons can be included in the production panel.<\/p>\n<h2 style=\"font-size: 29px; line-height: 1.28; color: #162d4d;\"><span class=\"ez-toc-section\" id=\"What_Are_Common_PCB_Backdrill_Defects\"><\/span>What Are Common PCB Backdrill Defects?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p style=\"margin: 0 0 17px; line-height: 1.72;\">Most defects come from incorrect data, depth errors, registration errors, or inadequate copper clearance.<\/p>\n<div style=\"width: 100%; overflow-x: auto; -webkit-overflow-scrolling: touch;\">\n<table style=\"border-collapse: collapse; width: 100%; min-width: 640px; margin: 20px 0 25px; font-size: 15px;\">\n<thead>\n<tr>\n<th style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left; background: #edf3f8; color: #142a43;\">Defect<\/th>\n<th style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left; background: #edf3f8; color: #142a43;\">Possible result<\/th>\n<th style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left; background: #edf3f8; color: #142a43;\">Typical cause<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Excessive residual stub<\/td>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Remaining reflection or resonance<\/td>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Drill stopped too early<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Over-drilling<\/td>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Open or weakened connection<\/td>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Drill entered the target layer<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Remaining barrel copper<\/td>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Incomplete stub removal<\/td>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Backdrill tool was too small<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Exposed nearby copper<\/td>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Shorting or insulation risk<\/td>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Insufficient clearance<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Misregistered backdrill<\/td>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Partial removal or sidewall damage<\/td>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">X-Y alignment error<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Wrong drilling side or depth<\/td>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">Stub remains or active barrel is damaged<\/td>\n<td style=\"border: 1px solid #d5dce5; padding: 11px 12px; vertical-align: top; text-align: left;\">File-labeling or CAM error<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<h2 style=\"font-size: 29px; line-height: 1.28; color: #162d4d;\"><span class=\"ez-toc-section\" id=\"What_Applications_Commonly_Use_PCB_Backdrilling\"><\/span>What Applications Commonly Use PCB Backdrilling?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p style=\"margin: 0 0 17px; line-height: 1.72;\">Backdrilling is most valuable on thick multilayer boards carrying fast signals through long vertical interconnects.<\/p>\n<ul style=\"margin: 10px 0 22px; padding-left: 25px;\">\n<li style=\"margin: 7px 0;\">Data-center servers<\/li>\n<li style=\"margin: 7px 0;\">Network switches and routers<\/li>\n<li style=\"margin: 7px 0;\">Telecom backplanes and midplanes<\/li>\n<li style=\"margin: 7px 0;\">High-speed storage systems<\/li>\n<li style=\"margin: 7px 0;\">FPGA and accelerator cards<\/li>\n<li style=\"margin: 7px 0;\">PCIe platforms<\/li>\n<li style=\"margin: 7px 0;\">Press-fit connector systems<\/li>\n<li style=\"margin: 7px 0;\">Test and measurement equipment<\/li>\n<li style=\"margin: 7px 0;\">Aerospace communication electronics<\/li>\n<li style=\"margin: 7px 0;\">Industrial and medical data-acquisition systems<\/li>\n<\/ul>\n<p style=\"margin: 0 0 17px; line-height: 1.72;\">It usually adds little value to thin, low-speed boards or designs where the signal uses nearly the full through-hole barrel.<\/p>\n<h2 style=\"font-size: 29px; line-height: 1.28; color: #162d4d;\"><span class=\"ez-toc-section\" id=\"How_to_Prepare_a_PCB_Backdrill_Project_for_Manufacturing\"><\/span>How to Prepare a PCB Backdrill Project for Manufacturing<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p style=\"margin: 0 0 17px; line-height: 1.72;\">Consider backdrilling before the layout is frozen because the larger tool may require more copper clearance than the original via.<\/p>\n<ul style=\"margin: 10px 0 22px; padding-left: 25px;\">\n<li style=\"margin: 7px 0;\">Confirm the final stackup and finished thickness.<\/li>\n<li style=\"margin: 7px 0;\">Identify only the nets that genuinely require backdrilling.<\/li>\n<li style=\"margin: 7px 0;\">Define the maximum acceptable residual stub.<\/li>\n<li style=\"margin: 7px 0;\">Mark each backdrilled via or connector pin.<\/li>\n<li style=\"margin: 7px 0;\">State drilling direction, start layer, and stop layer.<\/li>\n<li style=\"margin: 7px 0;\">Specify the final backdrill diameter.<\/li>\n<li style=\"margin: 7px 0;\">Check trace, pad, plane, and adjacent-hole clearances.<\/li>\n<li style=\"margin: 7px 0;\">Reduce the number of depth groups where routing permits.<\/li>\n<li style=\"margin: 7px 0;\">Generate separate NC files for each depth and drilling side.<\/li>\n<li style=\"margin: 7px 0;\">State coupon, microsection, and test requirements.<\/li>\n<\/ul>\n<p style=\"margin: 0 0 17px; line-height: 1.72;\">EBest Circuit (Best Technology) can review the layer pairs, drill diameters, copper clearances, and inspection notes before fabrication. Review our <a href=\"https:\/\/www.bestpcbs.com\/about\/capability.htm\">PCB manufacturing capabilities<\/a> and <a href=\"https:\/\/www.bestpcbs.com\/products\/pcba.htm\">PCB assembly services<\/a> when defining fabrication, component, inspection, and testing requirements. Early review is most useful while via locations and routing layers can still be changed without a major redesign.<\/p>\n<h2 style=\"font-size: 29px; line-height: 1.28; color: #162d4d;\"><span class=\"ez-toc-section\" id=\"FAQs\"><\/span>FAQs<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p class=\"faq-question\"><strong>Q1. What is PCB backdrill used for?<\/strong><\/p>\n<p style=\"margin: 0 0 17px; line-height: 1.72;\">It removes the unused plated section of a through-hole via to reduce via-stub resonance and reflection.<\/p>\n<p class=\"faq-question\"><strong>Q2. What is a via stub in a multilayer PCB?<\/strong><\/p>\n<p style=\"margin: 0 0 17px; line-height: 1.72;\">It is the unused conductive barrel extending beyond the last signal layer connected to the via.<\/p>\n<p class=\"faq-question\"><strong>Q3. How short should a PCB backdrill stub be?<\/strong><\/p>\n<p style=\"margin: 0 0 17px; line-height: 1.72;\">Around 10 mils is a common starting target, but the final value must match the channel requirement and drilling-depth tolerance.<\/p>\n<p class=\"faq-question\"><strong>Q4. Is backdrilling required for every high-speed PCB?<\/strong><\/p>\n<p style=\"margin: 0 0 17px; line-height: 1.72;\">No. It may be unnecessary when the signal uses most of the barrel or simulation shows adequate channel margin.<\/p>\n<p class=\"faq-question\"><strong>Q5. How does backdrilling reduce signal reflection?<\/strong><\/p>\n<p style=\"margin: 0 0 17px; line-height: 1.72;\">It shortens the open-ended via branch that receives and reflects part of the signal energy.<\/p>\n<p class=\"faq-question\"><strong>Q6. Is PCB backdrilling cheaper than using blind vias?<\/strong><\/p>\n<p style=\"margin: 0 0 17px; line-height: 1.72;\">It can be cheaper when blind vias would require sequential lamination. Blind vias may still be preferable for HDI routing.<\/p>\n<p class=\"faq-question\"><strong>Q7. Can through-hole component holes be backdrilled?<\/strong><\/p>\n<p style=\"margin: 0 0 17px; line-height: 1.72;\">Yes. Press-fit connector holes are a common example when mechanical retention and electrical connectivity remain protected.<\/p>\n<p class=\"faq-question\"><strong>Q8. Can a PCB be backdrilled from both sides?<\/strong><\/p>\n<p style=\"margin: 0 0 17px; line-height: 1.72;\">Yes. Two-sided drilling is used when unused barrel sections remain above and below an inner-layer connection.<\/p>\n<p class=\"faq-question\"><strong>Q9. Does PCB backdrilling increase lead time?<\/strong><\/p>\n<p style=\"margin: 0 0 17px; line-height: 1.72;\">It can add time for CAM preparation, drill setup, controlled-depth processing, and inspection.<\/p>\n<p class=\"faq-question\"><strong>Q10. What files are needed for a PCB backdrill quotation?<\/strong><\/p>\n<p style=\"margin: 0 0 17px; line-height: 1.72;\">Provide the PCB data, final stackup, primary and backdrill drill files, fabrication drawing, drill table, layer pairs, diameter, stub limit, and inspection requirements.<\/p>\n<p style=\"margin: 0 0 17px; line-height: 1.72;\">PCB backdrilling is a practical way to reduce via-stub effects without replacing every through-hole with a blind-via structure. It makes the most sense when signal-integrity analysis shows a clear benefit and the design has enough drilling clearance.<\/p>\n<p style=\"margin: 0 0 17px; line-height: 1.72;\">For <a href=\"https:\/\/www.bestpcbs.com\/blog\/pcb-backdrill\/\">PCB backdrill<\/a> stackup review, DFM feedback, or quotation support, contact EBest Circuit at <a href=\"mailto:sales@bestpcbs.com\">sales@bestpcbs.com<\/a>.<\/p>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>Learn how PCB backdrill removes via stubs, improves high-speed signal integrity, affects cost, and compares with blind vias.<\/p>\n","protected":false},"author":623,"featured_media":31055,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_uf_show_specific_survey":0,"_uf_disable_surveys":false,"footnotes":""},"categories":[174],"tags":[6885,6881,6882,6884,6883],"class_list":["post-31061","post","type-post","status-publish","format-standard","hentry","category-bestpcb","tag-backdrill-vs-blind-via","tag-pcb-backdrill","tag-pcb-backdrill-process","tag-pcb-backdrill-stub","tag-pcb-via-backdrill"],"acf":[],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.bestpcbs.com\/blog\/wp-json\/wp\/v2\/posts\/31061","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\/623"}],"replies":[{"embeddable":true,"href":"https:\/\/www.bestpcbs.com\/blog\/wp-json\/wp\/v2\/comments?post=31061"}],"version-history":[{"count":5,"href":"https:\/\/www.bestpcbs.com\/blog\/wp-json\/wp\/v2\/posts\/31061\/revisions"}],"predecessor-version":[{"id":31076,"href":"https:\/\/www.bestpcbs.com\/blog\/wp-json\/wp\/v2\/posts\/31061\/revisions\/31076"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.bestpcbs.com\/blog\/wp-json\/wp\/v2\/media\/31055"}],"wp:attachment":[{"href":"https:\/\/www.bestpcbs.com\/blog\/wp-json\/wp\/v2\/media?parent=31061"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bestpcbs.com\/blog\/wp-json\/wp\/v2\/categories?post=31061"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bestpcbs.com\/blog\/wp-json\/wp\/v2\/tags?post=31061"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}