{"id":2803,"date":"2026-10-16T09:00:00","date_gmt":"2026-10-16T01:00:00","guid":{"rendered":"https:\/\/www.jingpengpcb.com\/?p=2803"},"modified":"2026-10-08T20:14:47","modified_gmt":"2026-10-08T12:14:47","slug":"hf-pcb-drilling-materials","status":"publish","type":"post","link":"https:\/\/www.jingpengpcb.com\/en\/blog\/hf-pcb-drilling-materials\/","title":{"rendered":"How to Select Materials for Drilling High-Frequency PCBs? Selecting Drill Bits and Drilling Parameters"},"content":{"rendered":"<style>\n.jp-tw{overflow-x:auto;margin:26px 0;-webkit-overflow-scrolling:touch;}\n.jp-tw table{border-collapse:collapse;width:100%;min-width:560px;font-size:15px;line-height:1.65;background:#fff;}\n.jp-tw th,.jp-tw td{border:1px solid #dde3ea;padding:11px 14px;text-align:left;vertical-align:top;}\n.jp-tw thead th{background:#eef2f7;color:#1b2733;font-weight:700;white-space:nowrap;border-bottom:2px solid #c9d3de;}\n.jp-tw tbody tr:nth-child(even){background:#fafbfc;}\n.jp-tw tbody tr:hover{background:#f1f5fa;}\n.jp-tw tbody td:first-child{font-weight:600;color:#1b2733;}\n@media(max-width:767px){.jp-tw table{font-size:14px;min-width:520px;}.jp-tw th,.jp-tw td{padding:9px 11px;}}\n<\/style>\n<p>With the continuous advancement of science and technology\u2014particularly information technology\u2014manufacturing processes for printed circuit boards (PCBs) have also improved significantly to meet ever-increasing user demands. In recent years, the demand for printed circuit boards in the telecommunications sector has undergone some changes, particularly with regard to high-power printed circuit boards and<a href=\"\/en\/high-frequency-pcb\/\">High-Frequency Circuit Boards<\/a>Demand continues to rise. However, in the manufacturing process of high-frequency circuit boards, the drilling process has become a critical step. This article will take an in-depth look at the selection of materials used in the drilling process for high-frequency circuit boards and their characteristics.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" width=\"1000\" height=\"500\" class=\"alignnone size-large wp-image-4942\" src=\"https:\/\/www.jingpengpcb.com\/wp-content\/uploads\/2023\/07\/High-Frequency-PCBs.jpg\" alt=\"High-Frequency Circuit Boards\" srcset=\"https:\/\/www.jingpengpcb.com\/wp-content\/uploads\/2023\/07\/High-Frequency-PCBs.jpg 1000w, https:\/\/www.jingpengpcb.com\/wp-content\/uploads\/2023\/07\/High-Frequency-PCBs-300x150.jpg 300w, https:\/\/www.jingpengpcb.com\/wp-content\/uploads\/2023\/07\/High-Frequency-PCBs-768x384.jpg 768w, https:\/\/www.jingpengpcb.com\/wp-content\/uploads\/2023\/07\/High-Frequency-PCBs-400x200.jpg 400w\" sizes=\"auto, (max-width: 1000px) 100vw, 1000px\" \/><\/p>\n<h2>1. Why is drilling a critical process for high-frequency circuit boards?<\/h2>\n<p>When drilling standard FR-4 boards, problems usually stem from poor hole shape; however, drilling issues with high-frequency boards can directly affect their electrical performance. There are three reasons for this:<\/p>\n<ul>\n<li><strong>The Quality of the Hole Wall Affects the Reliability of Copper Plating<\/strong>: High-frequency boards commonly use materials such as PTFE and hydrocarbon ceramics. The bonding mechanism between the resin system and the glass fibers differs from that of FR-4, making it more prone to rough hole walls and resin shrinkage during drilling, and more susceptible to voids after copper plating.<\/li>\n<li><strong>Hole Position Accuracy Affects Impedance<\/strong>: If the alignment of the ground via array on a high-frequency board is off, it will alter the return path, which in turn will affect insertion loss and isolation.<\/li>\n<li><strong>Residue on the hole walls affects subsequent metallization<\/strong>: PTFE is chemically stable, so conventional debinding processes have limited effectiveness. If the smear (slag) generated during the drilling stage is not properly controlled, it is very difficult to remedy later on.<\/li>\n<\/ul>\n<p>Therefore, the materials (drill bits, cover plates, and spacer plates) and parameters used for drilling high-frequency boards must be selected with greater care than those for conventional boards.<\/p>\n<h2>2. Selection of Drill Bits<\/h2>\n<p>When drilling holes in high-frequency circuit boards, the choice of drill bit plays a crucial role in determining the final quality of the hole walls. Here are some key factors:<\/p>\n<ul>\n<li><strong>Material Quality:<\/strong> The drill bit itself must be of extremely high quality. The grain size of the tungsten carbide alloy must be very fine, reaching the submicron level. This material is free of pores and highly wear-resistant, making it ideal for drilling high-frequency circuit boards.<\/li>\n<li><strong>Diameter Tolerance:<\/strong> The diameter tolerance between the shank and the cutting edge of the drill bit should be within the range of 0 to 0.005 mm, and the concentricity tolerance of the entire drill bit should be within 0.005 mm to ensure a perfect geometric shape of the drilled hole.<\/li>\n<li><strong>Shape:<\/strong> Drill bits come in a variety of shapes, including standard, tapered, spade, and special types. The latter three are primarily used for drilling small holes; they can significantly reduce heat generation during drilling and minimize resin buildup on the borehole walls.<\/li>\n<\/ul>\n<p>Let\u2019s break down the concept of \u201csubmicron-grade tungsten carbide\u201d: The finer the tungsten carbide grains in a drill bit, the sharper the cutting edge and the more wear-resistant it is. Conventional drill bits have grain sizes of 0.5\u20131 \u03bcm, while submicron-grade bits can achieve 0.2\u20130.5 \u03bcm. The ceramic filler in high-frequency boards has high hardness (PTFE often contains silica and ceramic powder), so coarse-grained drill bits wear down extremely quickly and become dull after just a few hundred holes; Using submicron drill bits can extend service life by 2\u20133 times, while significantly improving hole wall roughness.<\/p>\n<h2>3. Drill Bit Types and Geometric Parameters<\/h2>\n<div class=\"jp-tw\">\n<table>\n<thead>\n<tr>\n<th>Drill Bit Types<\/th>\n<th>Features<\/th>\n<th>Applicable Pore Size<\/th>\n<th>Advantages<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Standard<\/td>\n<td>Standard Helix Angle and Vertex Angle<\/td>\n<td>0.3\u20136.5 mm<\/td>\n<td>Highly versatile and low-cost<\/td>\n<\/tr>\n<tr>\n<td>Tapered (Under-cut)<\/td>\n<td>The rear section of the blade is tapered to reduce friction<\/td>\n<td>0.2\u20130.5 mm<\/td>\n<td>Reduce heat generation and minimize resin contamination<\/td>\n<\/tr>\n<tr>\n<td>Spade (Flat)<\/td>\n<td>The cutting edge is flat, providing ample chip clearance space<\/td>\n<td>0.15\u20130.4 mm<\/td>\n<td>Smooth chip removal; suitable for small holes in thick plates<\/td>\n<\/tr>\n<tr>\n<td>Special Type (Special)<\/td>\n<td>Custom Geometry for Special Materials<\/td>\n<td>On Demand<\/td>\n<td>Optimization for PTFE and Ceramic Fillers<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<p>Two other geometric parameters have a significant impact on the quality of the bore wall:<\/p>\n<ul>\n<li><strong>Vertex Angle (Point Angle)<\/strong>: Standard 130\u00b0, 118\u00b0 for softer materials (such as pure PTFE) to achieve a sharper edge, and 140\u2013150\u00b0 for hard and brittle materials to reduce chipping.<\/li>\n<li><strong>Helix Angle<\/strong>: A large angle facilitates chip removal but reduces edge strength, while a small angle has the opposite effect. High-frequency board resin has high toughness, so a medium-to-large helix angle is generally used to improve chip removal.<\/li>\n<\/ul>\n<p><img loading=\"lazy\" decoding=\"async\" width=\"1280\" height=\"720\" class=\"alignnone size-large wp-image-8852\" src=\"https:\/\/www.jingpengpcb.com\/wp-content\/uploads\/2023\/08\/pcb-drill-bit-types-and-usage-precautions.jpg\" alt=\"Types of PCB Drill Bits and Precautions for Use\" srcset=\"https:\/\/www.jingpengpcb.com\/wp-content\/uploads\/2023\/08\/pcb-drill-bit-types-and-usage-precautions.jpg 1280w, https:\/\/www.jingpengpcb.com\/wp-content\/uploads\/2023\/08\/pcb-drill-bit-types-and-usage-precautions-300x169.jpg 300w, https:\/\/www.jingpengpcb.com\/wp-content\/uploads\/2023\/08\/pcb-drill-bit-types-and-usage-precautions-1024x576.jpg 1024w, https:\/\/www.jingpengpcb.com\/wp-content\/uploads\/2023\/08\/pcb-drill-bit-types-and-usage-precautions-768x432.jpg 768w\" sizes=\"auto, (max-width: 1280px) 100vw, 1280px\" \/><\/p>\n<h2>4. Selection of Drilling Parameters<\/h2>\n<p>Selecting the correct drilling parameters is one of the key factors in ensuring the quality of the hole walls in high-frequency circuit boards. Different drilling parameters can affect the final quality of the hole walls. Therefore, drilling parameters must be selected with care. Test results indicate that the drilling parameters provided by the supplier can serve as a reference for selection.<\/p>\n<p>Logic for assigning values to the three core parameters:<\/p>\n<div class=\"jp-tw\">\n<table>\n<thead>\n<tr>\n<th>Parameters<\/th>\n<th>Function<\/th>\n<th>Principles for Assigning Values<\/th>\n<th>Consequences of Dysregulation<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Spindle Speed (RPM)<\/td>\n<td>Determining the Cutting Line Speed<\/td>\n<td>Small orifices at high speeds, large orifices at low speeds; typically 60\u2013160 krpm<\/td>\n<td>Too low \u2192 rough hole walls; too high \u2192 overheating and charring<\/td>\n<\/tr>\n<tr>\n<td>Feed Rate (Feed)<\/td>\n<td>Determine the feed per revolution<\/td>\n<td>Typical: 1.5\u20134 m\/min; use the lower value for hard materials<\/td>\n<td>Too fast \u2192 chipped edges, broken blades; too slow \u2192 heat generated by friction<\/td>\n<\/tr>\n<tr>\n<td>Retract Speed<\/td>\n<td>Factors Affecting Chip Removal and Hole Finish Quality<\/td>\n<td>Generally, 2\u20133 times the feed rate is used.<\/td>\n<td>Too slow \u2192 Poor chip removal, scratches on the hole walls<\/td>\n<\/tr>\n<tr>\n<td>Number of Stacks<\/td>\n<td>Factors Affecting Hole Position Accuracy and Production Capacity<\/td>\n<td>2\u20133 standard boards, 1\u20132 high-frequency boards<\/td>\n<td>Excess \u2192 Hole Position Deviation, Burrs at the Exit<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<p>High-frequency boards are typically thicker than FR-4 boards with the same hole diameter. <strong>Reduce feed rate by 20\u201340%<\/strong>, while also appropriately increasing the spindle speed. This is because high-frequency materials have poor thermal conductivity, making it difficult for cutting heat to dissipate; if the feed rate is too fast, heat will accumulate instantly at the cutting edge, causing the resin to melt and shrink (which is the main source of resin contamination on the bore walls).<\/p>\n<h2>5. Three Specific Challenges in Drilling High-Frequency Materials<\/h2>\n<ul>\n<li><strong>The material is soft and sticky.<\/strong>: PTFE-based materials are soft and have a low melting point, so they tend to \u201cstick to the drill bit\u201d during drilling. The chips form strands rather than powder, and if chip removal is poor, they can scratch the bore wall. To address this, reduce the feed rate, increase the frequency of retraction, and use a spade-type drill bit with good chip-removal performance.<\/li>\n<li><strong>High filler hardness<\/strong>: High-frequency panels filled with ceramic contain large amounts of silicon dioxide or ceramic powder; the hardness of certain components is close to or even exceeds that of tungsten carbide, causing the drill bits to wear out extremely quickly. The solution is to use submicron-grade drill bits and significantly shorten the regrinding cycle.<\/li>\n<li><strong>High CTE on the Z-axis<\/strong>: The coefficient of thermal expansion of PTFE is significantly higher than that of FR-4. When heated during drilling, the material shrinks considerably, which can easily result in undersized holes and uneven hole walls. The solution is to control the temperature rise during drilling and verify the actual hole diameter before electroplating.<\/li>\n<\/ul>\n<h2>6. Service Life of Drill Bits<\/h2>\n<p>Conditions vary from one PCB manufacturer to another, so the service life of drill bits will also differ. Generally, when one of the drilling quality metrics drops to a level close to the specified limit, the drill bit needs to be replaced. Replaced drill bits can be reground or scrapped.<\/p>\n<p>What exactly do \u201cquality metrics\u201d refer to? On the production line, these four criteria are generally used as benchmarks:<\/p>\n<ul>\n<li><strong>Bore Surface Roughness<\/strong>: During slice inspection, replace the blade if the thickness exceeds the specified value (generally \u226425 \u03bcm).<\/li>\n<li><strong>Inlet Burrs and Peak Spikes<\/strong>: If any defects are detected during visual or microscopic inspection, replace the blade immediately.<\/li>\n<li><strong>Pore Size Deviation<\/strong>: Check the hole diameter; if it exceeds the tolerance, replace the cutter.<\/li>\n<li><strong>Hole Position Accuracy<\/strong>: If the CPK drops, change the tool.<\/li>\n<\/ul>\n<p>The service life of drill bits for high-frequency boards is typically only one-third to one-half that of conventional boards (possibly 500\u20131,500 holes versus 3,000\u20135,000 holes for conventional boards), and they can be reground fewer times.<strong>Make lifespan management based on the number of holes rather than time<\/strong>... is the balance between cost control and quality. For a systematic analysis of drilling quality issues, see<a href=\"\/en\/blog\/pcb-drilling-quality-issues\/\">Quality Issues in the PCB Drilling Process<\/a>\u3002<\/p>\n<h2>7. Other Factors in Drilling<\/h2>\n<p>When drilling holes in high-frequency circuit boards, there are several other factors to consider:<\/p>\n<ul>\n<li><strong>The purpose of perforated aluminum sheets:<\/strong> Drilling aluminum shims prevent the pressure foot from damaging the surface of high-frequency boards and improve the quality of the drilled boards. They also help prevent burrs from forming on the entry surface and improve the precision of the drilled holes.<\/li>\n<li><strong>The purpose of a drilling pad:<\/strong> A drill support plate prevents the drill bit from coming into contact with the work surface, which could damage the drilling platform and potentially cause the drill bit to break. In addition, it prevents burrs from forming on the exit surface.<\/li>\n<\/ul>\n<p>High-density fiberboard is often chosen as a drilling support plate because it has the appropriate hardness to effectively prevent burrs from forming without wearing down the drill bit. In addition, it contains no resin, so it effectively prevents contamination of the hole walls and is relatively cost-effective.<\/p>\n<p>Key Considerations for Selecting Cover Plates (Aluminum Sheets) and Spacer Plates:<\/p>\n<ul>\n<li><strong>Cover Plate<\/strong>: Typically, 0.15\u20130.2 mm aluminum foil is used. Since high-frequency boards have a softer surface, it is recommended to use slightly thicker aluminum foil or a composite cover sheet. The material must be flat and free of warping; otherwise, it may lift the board surface and cause hole positioning errors.<\/li>\n<li><strong>Shim<\/strong>: High-density fiberboard (HDF) is the most common choice, as it offers moderate hardness, is resin-free, and is cost-effective. Phenolic-resin-based backing boards are very hard but contain resin, which may contaminate the bore walls; wooden boards are prone to producing burrs. For high-frequency applications, HDF or specialized resin-free backing boards are the preferred choices.<\/li>\n<li><strong>Replacement Frequency<\/strong>: Inspect the backing plate after each drilling operation; if any noticeable grooves appear, replace it, otherwise burrs at the exit will increase significantly.<\/li>\n<\/ul>\n<p>When preparing to drill holes in high-frequency circuit boards, be sure to keep the board surface clean, ensure there are no foreign objects between the boards, and make sure the boards are in close contact with one another to prevent problems such as burrs or tool breakage.<\/p>\n<h2>8. Common Hole Defects and Countermeasures<\/h2>\n<p><img loading=\"lazy\" decoding=\"async\" width=\"1280\" height=\"720\" class=\"alignnone size-large wp-image-6590\" src=\"https:\/\/www.jingpengpcb.com\/wp-content\/uploads\/2023\/08\/pcb-back-drilling-2.jpg\" alt=\"PCB Drilling\" srcset=\"https:\/\/www.jingpengpcb.com\/wp-content\/uploads\/2023\/08\/pcb-back-drilling-2.jpg 1280w, https:\/\/www.jingpengpcb.com\/wp-content\/uploads\/2023\/08\/pcb-back-drilling-2-300x169.jpg 300w, https:\/\/www.jingpengpcb.com\/wp-content\/uploads\/2023\/08\/pcb-back-drilling-2-1024x576.jpg 1024w, https:\/\/www.jingpengpcb.com\/wp-content\/uploads\/2023\/08\/pcb-back-drilling-2-768x432.jpg 768w\" sizes=\"auto, (max-width: 1280px) 100vw, 1280px\" \/><\/p>\n<div class=\"jp-tw\">\n<table>\n<thead>\n<tr>\n<th>Defects<\/th>\n<th>Performance<\/th>\n<th>Main Reasons<\/th>\n<th>Countermeasures<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Resin Deposits on the Pore Walls (Smear)<\/td>\n<td>The pore walls are coated with a layer of resin film<\/td>\n<td>Feed rate too fast, dull drill bit, low melting point of the material<\/td>\n<td>Reduce feed rate, shorten tool change cycles, and improve slag removal<\/td>\n<\/tr>\n<tr>\n<td>Inlet Peak \/ Burr<\/td>\n<td>The copper foil at the orifice is curled up<\/td>\n<td>Uneven cover plate, dull drill bit, excessive feed rate<\/td>\n<td>Replace the cover plate, perform timely regrinding, and optimize parameters<\/td>\n<\/tr>\n<tr>\n<td>Rough bore wall<\/td>\n<td>The section shows distinct undulations.<\/td>\n<td>Drill bit wear; mismatch between rotational speed and feed rate<\/td>\n<td>Change the blade, re-adjust the parameters<\/td>\n<\/tr>\n<tr>\n<td>Nail Heading<\/td>\n<td>The inner layer of copper foil was deformed by compression<\/td>\n<td>Dull drill bit, excessive feed rate, too many stacked boards<\/td>\n<td>Tool changes, reducing the number of stacked boards<\/td>\n<\/tr>\n<tr>\n<td>Broken Sword<\/td>\n<td>The drill bit broke off inside the plate<\/td>\n<td>Feed rate too fast, foreign objects between the plates, poor concentricity<\/td>\n<td>Check the concentricity of the drill bit, clean the work surface, and reduce the parameters<\/td>\n<\/tr>\n<tr>\n<td>Hole Position Deviation<\/td>\n<td>The hole is offset from its designed position<\/td>\n<td>PCB layers sliding, cover plate warping, pins not securely clamped<\/td>\n<td>Secure the stacked panels more firmly and check the flatness of the cover plate<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<p><img loading=\"lazy\" decoding=\"async\" width=\"1280\" height=\"720\" class=\"alignnone size-large wp-image-8590\" src=\"https:\/\/www.jingpengpcb.com\/wp-content\/uploads\/2023\/08\/pcb-drilling-quality-issues.jpg\" alt=\"Quality Issues in the PCB Drilling Process\" srcset=\"https:\/\/www.jingpengpcb.com\/wp-content\/uploads\/2023\/08\/pcb-drilling-quality-issues.jpg 1280w, https:\/\/www.jingpengpcb.com\/wp-content\/uploads\/2023\/08\/pcb-drilling-quality-issues-300x169.jpg 300w, https:\/\/www.jingpengpcb.com\/wp-content\/uploads\/2023\/08\/pcb-drilling-quality-issues-1024x576.jpg 1024w, https:\/\/www.jingpengpcb.com\/wp-content\/uploads\/2023\/08\/pcb-drilling-quality-issues-768x432.jpg 768w\" sizes=\"auto, (max-width: 1280px) 100vw, 1280px\" \/><\/p>\n<h2>9. Bill of Materials for Drilling High-Frequency Circuit Boards<\/h2>\n<p>Checking this list before loading the material can help prevent most problems:<\/p>\n<ul>\n<li><strong>Drill bit<\/strong>: Sub-micron-grade tungsten carbide; pore size corresponds to model; concentricity \u22640.005 mm; service life is tracked based on the number of pores.<\/li>\n<li><strong>Cover Plate<\/strong>: Aluminum foil, 0.15\u20130.2 mm thick, flat and free of warping, and matching the dimensions of the panel surface.<\/li>\n<li><strong>Shim<\/strong>: High-density fiberboard, resin-free, with a smooth surface.<\/li>\n<li><strong>Specifications Table<\/strong>: Set separately based on material grade and pore size; do not use a single set of parameters for all cases.<\/li>\n<li><strong>Support<\/strong>: The dust extraction system is operating normally (chip removal and cooling), spindle cooling is normal, and the work surface is clean and free of foreign objects.<\/li>\n<\/ul>\n<p>For a complete list of process capabilities, see<a href=\"\/en\/capabilities\/\">PCB Manufacturing Capabilities<\/a>, See the comparison of the three drilling methods for 5G boards at<a href=\"\/en\/blog\/5g-pcb-drilling\/\">Three Common Drilling Methods for 5G PCBs<\/a>\u3002<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" width=\"852\" height=\"572\" class=\"alignnone size-large wp-image-9454\" src=\"https:\/\/www.jingpengpcb.com\/wp-content\/uploads\/2024\/01\/analysis-and-solutions-for-pcb-hole-breaks.jpg\" alt=\"PCB Hole Breakage\" srcset=\"https:\/\/www.jingpengpcb.com\/wp-content\/uploads\/2024\/01\/analysis-and-solutions-for-pcb-hole-breaks.jpg 852w, https:\/\/www.jingpengpcb.com\/wp-content\/uploads\/2024\/01\/analysis-and-solutions-for-pcb-hole-breaks-300x201.jpg 300w, https:\/\/www.jingpengpcb.com\/wp-content\/uploads\/2024\/01\/analysis-and-solutions-for-pcb-hole-breaks-768x516.jpg 768w\" sizes=\"auto, (max-width: 852px) 100vw, 852px\" \/><\/p>\n<p>By selecting the appropriate drill bits and taking into account drilling parameters and other factors, it is possible to ensure that the material selection and characteristics during the drilling process of high-frequency boards meet the requirements, thereby ultimately guaranteeing the quality and performance of the high-frequency boards.<\/p>\n<h2>Frequently Asked Questions<\/h2>\n<h3>Question 1: How important is the drilling process for high-frequency circuit boards?<\/h3>\n<p>The drilling process for high-frequency PCBs is critical because it directly affects the quality of the hole walls, which in turn impacts the overall performance and reliability of the PCB.<\/p>\n<h3>Question 2: Why is the choice of drill bit so critical?<\/h3>\n<p>The choice of drill bit affects the quality and efficiency of drilling. A high-quality drill bit can reduce heat generation and the accumulation of resin on the borehole walls.<\/p>\n<h3>Question 3: What are drilling parameters?<\/h3>\n<p>Drilling parameters include factors such as the drill bit's rotational speed, feed rate, and feed depth. Selecting these parameters correctly ensures high-quality drilling results.<\/p>\n<h3>Question 4: Why is it necessary to use perforated aluminum sheets and perforated shims?<\/h3>\n<p>Drilled aluminum sheets and drilled backing plates help prevent damage to the surface and hole walls of high-frequency circuit boards and improve drilling quality.<\/p>\n<h3>Question 5: How can we ensure that employees follow the correct operating procedures?<\/h3>\n<p>Company management should lead by example, demonstrate proper operating procedures, and provide training and education to ensure that employees understand how to operate equipment correctly and avoid \u201cfingerprint\u201d issues.<\/p>\n<h3>Question 6: Why should the feed rate be reduced when drilling holes in high-frequency circuit boards?<\/h3>\n<p>Because the thermal conductivity of PTFE and hydrocarbon-based materials is much lower than that of FR-4, cutting heat becomes concentrated at the cutting edge and cannot dissipate. If the feed rate is too fast, the resin will melt instantly and smear onto the hole walls, forming a smear that is difficult to remove completely during subsequent chip removal. Generally, reduce the feed rate by 20\u201340% compared to FR-4 for the same hole diameter, while appropriately increasing the spindle speed.<\/p>\n<h3>Question 7: Is drill bit life managed based on the number of holes drilled or on time?<\/h3>\n<p>Based on the number of holes drilled. Since board thickness, the number of layers, and materials vary significantly across different orders, managing drill bits by time can lead to \u201csome batches being overused while others are scrapped prematurely.\u201d The most reliable approach is to maintain a record of the cumulative number of holes drilled for each drill bit and mandate replacement or regrinding once a threshold is reached.<\/p>\n<h3>Question 8: What is a nail head, and why is it important to control it?<\/h3>\n<p>\"Pinhead\" refers to the phenomenon where, during drilling, the inner layer copper foil is squeezed by the drill bit and bulges toward the hole wall. Minor pinhead formation is acceptable (IPC specifies no more than 1.5 times the original copper thickness), but severe cases can cause abnormal contact between the inner-layer copper foil and the copper layer on the hole wall, affecting interlayer insulation and reliability. Control methods include timely bit replacement, feed rate control, and limiting the number of laminate layers.<\/p>\n<h3>Question 9: Why is it particularly difficult to remove resin residue from the walls of holes in PTFE sheets?<\/h3>\n<p>PTFE has an extremely high carbon-fluorine bond energy and is far more chemically stable than epoxy resin; conventional potassium permanganate-based degreasing solutions have limited effectiveness on it. In the industry, plasma treatment or sodium naphthalene solutions are generally used, but both the equipment and process costs are higher. This is why high-frequency PCBs place greater emphasis on \u201ccontrolling smear from the drilling stage\u201d rather than relying on remedial measures in later stages.<\/p>\n<h3>Question 10: How much more does it cost to drill holes in high-frequency boards compared to conventional boards?<\/h3>\n<p>The main cost increases come from three areas: drill bit wear (2\u20133 times shorter service life, and higher unit cost for submicron drill bits), reduced production capacity (slower feed rates and fewer stacked boards), and stricter inspection (higher proportion of random sampling during slicing). Overall, the drilling cost for high-frequency PCBs is typically 2\u20134 times that of conventional PCBs. For material selection and alternative solutions, see<a href=\"\/en\/blog\/high-frequency-microwave-board\/\">High-Frequency Microwave Board Selection Guide<\/a>\u3002<\/p>\n<p><strong>Related Recommendations<\/strong>\uff1a<a href=\"\/en\/blog\/5g-high-frequency-board-millimeter-wave-communication\/\">Learn About 5G High-Frequency Boards<\/a> \u00b7 <a href=\"\/en\/blog\/ink-fpc-manufacturing-process\/\">The Role of Ink in the FPC Manufacturing Process<\/a> \u00b7 <a href=\"\/en\/high-frequency-pcb\/\">High-Frequency PCBs<\/a><\/p>","protected":false},"excerpt":{"rendered":"<p>\u968f\u7740\u79d1\u5b66\u6280\u672f\uff0c\u5c24\u5176\u662f\u4fe1\u606f\u6280\u672f\u7684\u4e0d\u65ad\u53d1\u5c55\uff0c\u5370\u5236\u7535\u8def\u677f\uff08PCB\uff09\u7684\u5236\u9020\u5de5\u827a\u6280\u672f\u4e5f\u5f97\u5230\u4e86\u663e\u8457\u63d0\u9ad8\uff0c\u4ee5\u6ee1\u8db3\u65e5\u76ca\u589e\u957f\u7684\u7528 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":4942,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"slim_seo":{"title":"How to Select Materials for Drilling High-Frequency PCBs? Selecting Drill Bits and Drilling Parameters","description":"How to Select Materials for Drilling High-Frequency PCBs? This article explains drill bit selection, drilling parameter settings, drill bit life, and the impact of other factors during the drilling process. By following the checklist provided in this article, you can avoid rework on your first prototype."},"_slim_seo_primary_term_category":0,"_slim_seo_primary_term_post_tag":0,"footnotes":""},"categories":[406,26],"tags":[],"class_list":["post-2803","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-pcb-manufacturing","category-blog"],"_links":{"self":[{"href":"https:\/\/www.jingpengpcb.com\/en\/wp-json\/wp\/v2\/posts\/2803","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.jingpengpcb.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.jingpengpcb.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.jingpengpcb.com\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.jingpengpcb.com\/en\/wp-json\/wp\/v2\/comments?post=2803"}],"version-history":[{"count":6,"href":"https:\/\/www.jingpengpcb.com\/en\/wp-json\/wp\/v2\/posts\/2803\/revisions"}],"predecessor-version":[{"id":19890,"href":"https:\/\/www.jingpengpcb.com\/en\/wp-json\/wp\/v2\/posts\/2803\/revisions\/19890"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.jingpengpcb.com\/en\/wp-json\/wp\/v2\/media\/4942"}],"wp:attachment":[{"href":"https:\/\/www.jingpengpcb.com\/en\/wp-json\/wp\/v2\/media?parent=2803"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.jingpengpcb.com\/en\/wp-json\/wp\/v2\/categories?post=2803"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.jingpengpcb.com\/en\/wp-json\/wp\/v2\/tags?post=2803"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}