{"id":1957,"date":"2026-11-12T11:00:00","date_gmt":"2026-11-12T03:00:00","guid":{"rendered":"https:\/\/www.jingpengpcb.com\/?p=1957"},"modified":"2026-10-10T00:08:01","modified_gmt":"2026-10-09T16:08:01","slug":"pcb-prototype-process-flow","status":"publish","type":"post","link":"https:\/\/www.jingpengpcb.com\/en\/blog\/pcb-prototype-process-flow\/","title":{"rendered":"What are the processes involved in PCB prototyping? From internal layer traces to solder mask text"},"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><strong>Printed circuit boards (PCBs) play a crucial role in electronic devices. They are core components that connect various electronic components and provide a stable operating environment for circuits. This article will provide a detailed overview of the prototyping process for six-layer PCBs to help you better understand this critical manufacturing process.<\/strong><\/p>\n<h2>H1: Preparation of the Inner Layer Traces<\/h2>\n<p>The first step in PCB fabrication is cutting the copper-clad laminate to a size suitable for processing. Before lamination, the copper foil surface is typically roughened to improve the adhesion of the dry film photoresist. Next, the substrate is placed in a UV exposure unit to transfer the circuit pattern from the film to the dry film photoresist. After exposure, the protective film is peeled off, and the unexposed areas are removed by developing with an aqueous sodium carbonate solution. Next, a hydrogen peroxide solution is used to etch away the exposed copper foil, thereby forming the circuit pattern. Finally, the dry film photoresist is washed off using a mild sodium hydroxide solution.<\/p>\n<h2>H2: Laminating<\/h2>\n<p>Before lamination, the inner layers must undergo a blackening (oxidation) treatment to improve the insulation properties of the copper surface and increase the surface roughness of the copper on the inner circuit layers, thereby ensuring better adhesion. The inner layers are riveted together using a riveting machine, then neatly stacked between mirror-finished steel plates and fed into a vacuum laminating machine. Under appropriate temperature and pressure, the film is cured and bonded. After lamination, the circuit boards undergo automated X-ray-guided drilling to create reference holes, followed by appropriate cutting.<\/p>\n<h2>Advanced: Key Control Points in the Upstream Process<\/h2>\n<p>The original text breaks down the prototyping process into ten steps. The initial stages (cutting, inner layers, and lamination) establish the baseline for all subsequent processes; once a problem arises here, it cannot be corrected. The key control points for each process are as follows:<\/p>\n<div class=\"jp-tw\">\n<table>\n<thead>\n<tr>\n<th>Process Steps<\/th>\n<th>Key Control Items<\/th>\n<th>Common Defects<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Cutting<\/td>\n<td>Dimensions, longitudinal and transverse directions, and thickness uniformity<\/td>\n<td>Dimensional Deviations, Warpage<\/td>\n<\/tr>\n<tr>\n<td>Preprocessing<\/td>\n<td>Cleanliness and Roughness of Copper Surfaces<\/td>\n<td>Insufficient dry film adhesion, open circuit<\/td>\n<\/tr>\n<tr>\n<td>Lamination \/ Exposure<\/td>\n<td>Film thickness, exposure energy, alignment<\/td>\n<td>Incomplete development, line width deviation<\/td>\n<\/tr>\n<tr>\n<td>Etching<\/td>\n<td>Etch Rate, Side-Etch Compensation<\/td>\n<td>Line width out of tolerance, residual copper<\/td>\n<\/tr>\n<tr>\n<td>Black Oxidation \/ Browning<\/td>\n<td>Uniformity of Copper Surface Roughening<\/td>\n<td>Delamination after pressing<\/td>\n<\/tr>\n<tr>\n<td>Lamination and Pressing<\/td>\n<td>Heating Rate, Pressure Curve, Vacuum Level<\/td>\n<td>Bubbles, Creases, Delamination<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<p>Among them<strong>Pressing is the riskiest step in the manufacture of multilayer boards.<\/strong>. During the heating process, the resin undergoes four stages: softening, melting and flowing, gelation, and curing. Even a slight deviation in the balance between pressure and temperature can result in insufficient resin filling, interlayer bubbles, or wrinkling of the copper foil\u2014defects that are virtually impossible to correct once the lamination process is complete.<\/p>\n<ul>\n<li><strong>Excessively rapid heating rate<\/strong>: The resin gels before it has time to flow sufficiently, resulting in resin shortages and voids;<\/li>\n<li><strong>Insufficient pressure<\/strong>: Volatile substances cannot be expelled, causing bubbles to form;<\/li>\n<li><strong>Asymmetric Stacking<\/strong>: Uneven stress after cooling causes warpage that exceeds the specified limit.<\/li>\n<\/ul>\n<ol>\n<li>Verify the symmetry of the stacked structure and material matching;<\/li>\n<li>Set the heating rate and pressure curves based on the material system;<\/li>\n<li>After lamination, perform X-ray inspections to verify alignment and conduct random sample inspections.<\/li>\n<\/ol>\n<p><img loading=\"lazy\" decoding=\"async\" width=\"1280\" height=\"720\" class=\"alignnone size-large wp-image-5986\" src=\"https:\/\/www.jingpengpcb.com\/wp-content\/uploads\/2023\/07\/multilayer-board-lamination.jpg\" alt=\"Laminating Multilayer Printed Circuit Boards\" srcset=\"https:\/\/www.jingpengpcb.com\/wp-content\/uploads\/2023\/07\/multilayer-board-lamination.jpg 1280w, https:\/\/www.jingpengpcb.com\/wp-content\/uploads\/2023\/07\/multilayer-board-lamination-300x169.jpg 300w, https:\/\/www.jingpengpcb.com\/wp-content\/uploads\/2023\/07\/multilayer-board-lamination-1024x576.jpg 1024w, https:\/\/www.jingpengpcb.com\/wp-content\/uploads\/2023\/07\/multilayer-board-lamination-768x432.jpg 768w, https:\/\/www.jingpengpcb.com\/wp-content\/uploads\/2023\/07\/multilayer-board-lamination-400x225.jpg 400w\" sizes=\"auto, (max-width: 1280px) 100vw, 1280px\" \/><\/p>\n<p>Challenges in Laminating See<a href=\"\/en\/blog\/difficulties-and-key-process-control-in-manufacturing-high-rise-pcb\/\">Challenges in the Manufacturing of High-Layer-Count Printed Circuit Boards and Control of Key Processes<\/a>; For the CAM process, see<a href=\"\/en\/blog\/the-9-basic-steps-of-cam-production\/\">The 9 Basic Steps of CAM Production<\/a>\u3002<\/p>\n<h2>H3: Drilling<\/h2>\n<p>PCB boards require a CNC drilling machine to drill through-holes for interlayer circuits and mounting holes for soldering components.<\/p>\n<h2>H4: Plated Through-Holes<\/h2>\n<p>After forming the interlayer through-holes, a layer of copper must be deposited inside the holes to establish electrical continuity between layers. First, the holes are cleaned of burrs and powder residue through vigorous brushing and high-pressure rinsing. Next, the clean hole walls are dipped in tin.<\/p>\n<h2>H5: Primary Copper<\/h2>\n<p>The circuit board was submerged in<a href=\"\/en\/pcb-factory\/\">Chemical Copper<\/a>In the solution, copper ions are reduced and deposited on the wall of the via, forming a through-hole circuit. Next, the copper layer inside the via is thickened to the appropriate thickness using a copper sulfate electroplating bath to prepare it for subsequent processing.<\/p>\n<h2>H6: Preparation of the Outer Layer Circuit<\/h2>\n<p>The preparation method for outer-layer circuits is similar to that for inner-layer circuits, but there are two methods: positive-film and negative-film. In the negative process, the copper is etched directly after development, and the process is completed by removing the film. In the positive process, a second copper plating and tin-lead plating are required after development, followed by film removal. Finally, a mixture of ammonia and copper chloride is used to remove the exposed copper foil, forming the circuit. Afterward, the tin-lead layer is stripped using a tin-lead stripping solution.<\/p>\n<h2>Advanced: Key Control Points for Drilling and Hole Metallization<\/h2>\n<p>In the original text, H3 through H5 cover drilling, through-hole plating, and the first copper layer. These three steps collectively determine the reliability of interlayer interconnects and are the most common reasons for rejections during the prototyping phase:<\/p>\n<div class=\"jp-tw\">\n<table>\n<thead>\n<tr>\n<th>Process Steps<\/th>\n<th>Key Control Items<\/th>\n<th>Common Defects<\/th>\n<th>Consequences<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Drilling<\/td>\n<td>Drill bit condition, rotational speed and feed rate, number of stacked plates<\/td>\n<td>Rough hole walls, nail heads, burrs<\/td>\n<td>Poor Copper Plating Adhesion<\/td>\n<\/tr>\n<tr>\n<td>Removing Resin Residue<\/td>\n<td>Degree of resin removal, roughening of pore walls<\/td>\n<td>Drilling residue, excessive erosion<\/td>\n<td>Pore-wall separation, inner-layer interconnect failure<\/td>\n<\/tr>\n<tr>\n<td>Chemical Copper Plating<\/td>\n<td>Activation and Deposition Rates<\/td>\n<td>Incomplete pore wall coverage<\/td>\n<td>Intermittent or open circuit in the copper hole<\/td>\n<\/tr>\n<tr>\n<td>Thickened Plating<\/td>\n<td>Current Density, Mass Transfer in the Electrolyte, Additives<\/td>\n<td>The hole walls are too thin, and the plating is uneven.<\/td>\n<td>Thermal Cycling Cracking<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<p>The key indicator for assessing the quality of metalization in through-holes is<strong>Hole Copper Thickness and Uniform Plating Capability<\/strong>. The standard requirement is that the average hole copper thickness be no less than 20 \u03bcm (IPC Class 2), while high-reliability products often require 25 \u03bcm or more; the uniform plating capability reflects how closely the copper thickness in the center of the hole matches that on the board surface.<\/p>\n<ul>\n<li><strong>The wall-to-diameter ratio is a hard constraint.<\/strong>: When the ratio of plate thickness to hole diameter exceeds 10:1, mass transfer in the plating bath becomes difficult, and pulse plating is required;<\/li>\n<li><strong>Drill bit life should be managed based on the number of holes drilled.<\/strong>: A dull drill bit can cause rough hole walls and resin buildup;<\/li>\n<li><strong>The plating solution must be analyzed regularly.<\/strong>: Additive consumption and contamination directly affect the uniformity of the plating process.<\/li>\n<\/ul>\n<ol>\n<li>Calculate the wall-to-diameter ratio based on the hole diameter and plate thickness; if it exceeds the limit, adjust the design first;<\/li>\n<li>Set the drill bit replacement schedule and conduct random inspections of the hole wall quality;<\/li>\n<li>Prepare test specimens by slicing them directly from the furnace and measure the copper thickness at three points;<\/li>\n<li>Conduct a thermal stress test to confirm that there is no delamination.<\/li>\n<\/ol>\n<p><img loading=\"lazy\" decoding=\"async\" width=\"1280\" height=\"720\" class=\"alignnone size-large wp-image-6443\" src=\"https:\/\/www.jingpengpcb.com\/wp-content\/uploads\/2023\/08\/pcb-back-drilling-1.jpg\" alt=\"PCB Drilling\" srcset=\"https:\/\/www.jingpengpcb.com\/wp-content\/uploads\/2023\/08\/pcb-back-drilling-1.jpg 1280w, https:\/\/www.jingpengpcb.com\/wp-content\/uploads\/2023\/08\/pcb-back-drilling-1-300x169.jpg 300w, https:\/\/www.jingpengpcb.com\/wp-content\/uploads\/2023\/08\/pcb-back-drilling-1-1024x576.jpg 1024w, https:\/\/www.jingpengpcb.com\/wp-content\/uploads\/2023\/08\/pcb-back-drilling-1-768x432.jpg 768w\" sizes=\"auto, (max-width: 1280px) 100vw, 1280px\" \/><\/p>\n<p>For the copper plating process, see<a href=\"\/en\/blog\/pcb-copper-plating-process\/\">Common Issues and Solutions in the Copper Plating Process<\/a>; For laser drilling, see<a href=\"\/en\/blog\/laser-drilling-hdi-circuit-board\/\">Applications of Laser Drilling in HDI Printed Circuit Boards<\/a>\u3002<\/p>\n<h2>H7: Solder Mask Ink Text Printing<\/h2>\n<p>The text, logos, or part numbers requested by the customer are printed on the surface of the circuit board using screen printing. The text ink is then cured using heat or ultraviolet light.<\/p>\n<h2>H8: Contact Machining<\/h2>\n<p>Solder mask\u2014a green coating\u2014covers most of the copper surface of the circuit traces, leaving only the terminal pads exposed for component soldering, electrical testing, and circuit board interconnections. These terminal pads require an additional protective layer to prevent the formation of oxides during long-term use, which could affect circuit stability.<\/p>\n<h2>Advanced: Outer-layer Traces, Solder Mask, and Key Control Points in Back-End Processes<\/h2>\n<p>In the original text, H6 through H10 refer to the outer layer and subsequent processing steps. This stage directly determines the finished product\u2019s appearance, weldability, and delivery condition:<\/p>\n<div class=\"jp-tw\">\n<table>\n<thead>\n<tr>\n<th>Process Steps<\/th>\n<th>Key Control Items<\/th>\n<th>Common Defects<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Outer Layer Traces<\/td>\n<td>Exposure Alignment, Etch Compensation, Line Width Uniformity<\/td>\n<td>Line width out of tolerance, notches, short circuits<\/td>\n<\/tr>\n<tr>\n<td>Solder Mask Printing<\/td>\n<td>Ink thickness, exposure energy, development<\/td>\n<td>Misalignment, oil leakage, incomplete development<\/td>\n<\/tr>\n<tr>\n<td>Text Printing<\/td>\n<td>Character Clarity and Curing<\/td>\n<td>Blurred or missing characters<\/td>\n<\/tr>\n<tr>\n<td>Surface Treatment<\/td>\n<td>Thickness, Flatness, Weldability<\/td>\n<td>Poor soldering, oxidation<\/td>\n<\/tr>\n<tr>\n<td>Forming<\/td>\n<td>Dimensions, Burrs, V-Cut Depth<\/td>\n<td>Dimensional deviations, difficulty in separating the boards<\/td>\n<\/tr>\n<tr>\n<td>Electrical Testing<\/td>\n<td>Test Coverage and Acceptance Criteria<\/td>\n<td>Failure to detect an open circuit or short circuit<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<p>Although surface treatment is not listed separately in the original text, it is a critical step that affects customer use. Each common method has its own scope of application:<strong>Tin Plating<\/strong>Low cost but average flatness;<strong>ENIG<\/strong>Good flatness, suitable for fine pitch and long-term storage;<strong>OSP<\/strong>It is low-cost and has good flatness, but it has a relatively short shelf life.<\/p>\n<ul>\n<li><strong>Incomplete development of the solder mask can directly lead to poor solderability.<\/strong>: A thin layer of ink remains on the pad, preventing the solder paste from bonding with the copper;<\/li>\n<li><strong>Insufficient surface treatment thickness will shorten the weldable window.<\/strong>: When storage and turnaround times are long, a more durable treatment should be selected;<\/li>\n<li><strong>Molding burrs can interfere with assembly<\/strong>: This is particularly noticeable with metal substrates and thick copper plates.<\/li>\n<\/ul>\n<ol>\n<li>Verify that the surface treatment method meets the storage requirements;<\/li>\n<li>Confirm the forming method (CNC edge milling, V-cut, stamping) and dimensional tolerances;<\/li>\n<li>Confirm electrical test coverage and packaging methods.<\/li>\n<\/ol>\n<p><img loading=\"lazy\" decoding=\"async\" width=\"1280\" height=\"720\" class=\"alignnone size-large wp-image-6091\" src=\"https:\/\/www.jingpengpcb.com\/wp-content\/uploads\/2023\/07\/soldermask.jpg\" alt=\"Solder Mask\" srcset=\"https:\/\/www.jingpengpcb.com\/wp-content\/uploads\/2023\/07\/soldermask.jpg 1280w, https:\/\/www.jingpengpcb.com\/wp-content\/uploads\/2023\/07\/soldermask-300x169.jpg 300w, https:\/\/www.jingpengpcb.com\/wp-content\/uploads\/2023\/07\/soldermask-1024x576.jpg 1024w, https:\/\/www.jingpengpcb.com\/wp-content\/uploads\/2023\/07\/soldermask-768x432.jpg 768w, https:\/\/www.jingpengpcb.com\/wp-content\/uploads\/2023\/07\/soldermask-400x225.jpg 400w\" sizes=\"auto, (max-width: 1280px) 100vw, 1280px\" \/><\/p>\n<p>For surface treatment, see<a href=\"\/en\/blog\/pcb-surface-plating\/\">PCB Surface Treatment<\/a>; For manufacturing capabilities, see<a href=\"\/en\/pcb-factory\/\">PCB Manufacturing<\/a>\u3002<\/p>\n<h2>H9: Forming and Cutting<\/h2>\n<p>A CNC forming machine is used to cut the circuit boards to the dimensions and shape specified by the customer, after which the powder and ionic contaminants on the surface of the circuit boards are washed off.<\/p>\n<h2>H10: Inspection and Packaging<\/h2>\n<p>Finally, inspect the circuit boards. Common packaging methods include PE film packaging, heat-shrink film packaging, and vacuum packaging.<\/p>\n<p>The above provides a detailed breakdown of the prototyping and manufacturing process for six-layer PCBs. We hope this information is helpful to you. If you have any further questions about the PCB manufacturing process, please feel free to contact us.<\/p>\n<h2>Advanced: Differences in Processes Between Prototyping and Mass Production<\/h2>\n<p>Although both involve the same ten production steps, there are clear differences in how prototyping and mass production are carried out. Understanding these differences helps us interpret prototyping results correctly:<\/p>\n<div class=\"jp-tw\">\n<table>\n<thead>\n<tr>\n<th>Dimension<\/th>\n<th>Proofing<\/th>\n<th>Mass Production<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Production Scheduling Methods<\/td>\n<td>Individual orders, slow pace<\/td>\n<td>Continuous operation, fixed cycle time<\/td>\n<\/tr>\n<tr>\n<td>Parameter Control<\/td>\n<td>Can be fine-tuned as needed<\/td>\n<td>According to standard parameters<\/td>\n<\/tr>\n<tr>\n<td>Inspection Rate<\/td>\n<td>High-proportion or 100% inspection<\/td>\n<td>According to the sampling plan<\/td>\n<\/tr>\n<tr>\n<td>Material Batch<\/td>\n<td>Single batch<\/td>\n<td>Mixing multiple batches<\/td>\n<\/tr>\n<tr>\n<td>Engineering Intervention<\/td>\n<td>Every order is reviewed manually<\/td>\n<td>Depend on standardized documents<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<p>This leads to two practical suggestions:<strong>First, a successful prototype does not guarantee that mass production will be risk-free; mid-volume validation is essential.<\/strong>\uff1b<strong>Second, when creating a sample, you should clearly state any special requirements all at once.<\/strong>Otherwise, the factory will produce the items according to the default standards, and making changes during mass production will require creating new prototypes.<\/p>\n<ul>\n<li><strong>Items to Confirm During the Proofing Stage<\/strong>: Stacking, impedance, surface treatment, forming methods, special process requirements;<\/li>\n<li><strong>Items to be verified before mass production<\/strong>: Repeatability and yield levels of parameters under standard conditions;<\/li>\n<li><strong>Items to track over the long term<\/strong>: Consistency between batches, trends in the drift of critical dimensions.<\/li>\n<\/ul>\n<p><img loading=\"lazy\" decoding=\"async\" width=\"600\" height=\"350\" class=\"alignnone size-large wp-image-9520\" src=\"https:\/\/www.jingpengpcb.com\/wp-content\/uploads\/2023\/08\/specification-and-requirements-for-screen-printing-layer-of-pcb-board.jpg\" alt=\"Specifications and Requirements for the Screen-Printed Layer of PCBs\" srcset=\"https:\/\/www.jingpengpcb.com\/wp-content\/uploads\/2023\/08\/specification-and-requirements-for-screen-printing-layer-of-pcb-board.jpg 600w, https:\/\/www.jingpengpcb.com\/wp-content\/uploads\/2023\/08\/specification-and-requirements-for-screen-printing-layer-of-pcb-board-300x175.jpg 300w\" sizes=\"auto, (max-width: 600px) 100vw, 600px\" \/><\/p>\n<p>For a glossary of terms, see<a href=\"\/en\/blog\/pcb-english-part-1\/\">Chinese-English Glossary of Common Technical Terms Used in Printed Circuit Board Manufacturing<\/a>; See the standard index at<a href=\"\/en\/blog\/34-commonly-used-ipc-standards-for-printed-circuit-boards\/\">34 Common IPC Standards for Printed Circuit Boards<\/a>\u3002<\/p>\n<h2>Advanced: Verifying the Appearance and Dimensions of Prototypes<\/h2>\n<p>After the prototype is returned to the factory, in addition to functional testing, it is equally important to verify its appearance and dimensions. We recommend going through the following steps in the order listed below:<\/p>\n<ul>\n<li><strong>Dimensions and Hole Locations<\/strong>: Measure using a caliper or imaging system, paying particular attention to the mounting holes and fit dimensions;<\/li>\n<li><strong>Appearance of the Panel Surface<\/strong>: Check whether the solder mask is misaligned or has lost its coating, and whether the screen printing is clear;<\/li>\n<li><strong>Pads and Surface Treatment<\/strong>: Verify that there are no ink residues on the pads and that the surface finish is uniform in color;<\/li>\n<li><strong>Panel Edging and Forming<\/strong>: Check for burrs or chipped edges, and verify that the V-CUT depth is correct;<\/li>\n<li><strong>Warping<\/strong>: Place the board on the platform and use a feeler gauge to measure the warpage, ensuring it is within the specified range.<\/li>\n<\/ul>\n<p>These inspection steps don\u2019t take much time, yet they can catch most common manufacturing issues. In particular, solder mask misalignment and ink residue on pads\u2014which typically cannot be detected during electrical testing\u2014directly affect soldering yield.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" width=\"1280\" height=\"853\" class=\"alignnone size-large wp-image-8994\" src=\"https:\/\/www.jingpengpcb.com\/wp-content\/uploads\/2024\/05\/mother-board-electronic-electronics-5365236.jpg\" alt=\"PCB Design\" srcset=\"https:\/\/www.jingpengpcb.com\/wp-content\/uploads\/2024\/05\/mother-board-electronic-electronics-5365236.jpg 1280w, https:\/\/www.jingpengpcb.com\/wp-content\/uploads\/2024\/05\/mother-board-electronic-electronics-5365236-300x200.jpg 300w, https:\/\/www.jingpengpcb.com\/wp-content\/uploads\/2024\/05\/mother-board-electronic-electronics-5365236-1024x682.jpg 1024w, https:\/\/www.jingpengpcb.com\/wp-content\/uploads\/2024\/05\/mother-board-electronic-electronics-5365236-768x512.jpg 768w\" sizes=\"auto, (max-width: 1280px) 100vw, 1280px\" \/><\/p>\n<h2>Frequently Asked Questions<\/h2>\n<h3>1. How long does it usually take to produce a prototype of a six-layer board?<\/h3>\n<p>Standard lead times are approximately 5\u201310 business days, depending on the number of layers, manufacturing complexity, and surface treatment. If you choose expedited service, the lead time can be reduced to 24\u201372 hours, but an expedited fee will apply. Please note that expedited service only reduces the waiting time; the production steps themselves cannot be skipped. Therefore, even with expedited service, boards with a very high level of complexity will still require a longer production cycle.<\/p>\n<h3>2. What files are required for a proof?<\/h3>\n<p>The most basic requirements are Gerber files (including circuit patterns, solder mask, silkscreen, and drill patterns for each layer) and a description of the manufacturing specifications. If impedance control is required, an impedance table must also be provided; if there are specific stack-up requirements, a stack-up diagram should be included as well. If only Gerber files are provided without process specifications, the factory will manufacture the PCB according to default standards, which may result in a product that does not meet expectations.<\/p>\n<h3>3. Why do prototyping factories perform engineering verification first?<\/h3>\n<p>This is because manufacturability issues\u2014such as insufficient via rings, overly tight line spacing, asymmetrical stackups, and solder mask bridges that are too narrow\u2014must be identified before production begins. This step can significantly reduce the rework rate. The level of expertise demonstrated in engineering feedback is also a key indicator of a supplier\u2019s capabilities.<\/p>\n<h3>4. Why can't an open circuit in the inner layer be repaired?<\/h3>\n<p>After lamination, the inner-layer traces are encapsulated within the board, making them inaccessible and impossible to repair. If an open circuit or short circuit occurs in any inner layer, the entire board must be scrapped. This is why inner-layer AOI inspection is a mandatory process in the manufacturing of high-layer-count printed circuit boards.<\/p>\n<h3>5. What is a typical appropriate quantity for a sample run?<\/h3>\n<p>Typically, 5\u201310 boards are ordered. If the project is expected to enter mass production later, we recommend ordering a few extra boards: since engineering costs account for a significant portion of a single order, the marginal cost of ordering a few extra boards is much lower than placing another order later. Additionally, the extra boards can be used for destructive testing and as spares.<\/p>\n<h3>6. At which stage of the process should impedance control be verified?<\/h3>\n<p>The actual dielectric thickness is determined after lamination, the actual line width is measured after etching, and finally, a prototype is fabricated for impedance testing, followed by the issuance of a report. Therefore, impedance is the result of the combined effects of multiple processes, and any deviation at any stage will affect the final result.<\/p>\n<h3>7. Can we switch factories for prototyping and mass production?<\/h3>\n<p>Technically, it is possible, but not recommended. Etching compensation and lamination parameters may vary between factories and depending on the material supplier; switching factories is equivalent to performing the process adaptation all over again. If you must switch factories, we recommend conducting a small-batch validation first and providing actual measurement data from the prototyping stage for reference.<\/p>\n<h3>8. What additional verification steps are needed after the prototype is completed?<\/h3>\n<p>We recommend completing at least three tasks: First, conduct functional and electrical testing to confirm the design\u2019s feasibility; second, verify critical dimensions through actual measurements, particularly fit dimensions and mounting hole locations; and third, if necessary, perform cross-section analysis to inspect the copper holes and interlayer bonding. Once these three tasks are completed, proceeding to medium-volume production will carry significantly less risk.<\/p>\n<p><strong>Related Processes<\/strong>\uff1a<a href=\"\/en\/blog\/pcb-english-part-1\/\">Chinese-English Glossary of Common Technical Terms Used in Printed Circuit Board Manufacturing<\/a><\/p>","protected":false},"excerpt":{"rendered":"<p>\u5728\u7535\u5b50\u8bbe\u5907\u4e2d\uff0c\u5370\u5237\u7535\u8def\u677f\uff08PCB\uff09\u626e\u6f14\u7740\u81f3\u5173\u91cd\u8981\u7684\u89d2\u8272\u3002\u5b83\u662f\u8fde\u63a5\u5404\u79cd\u7535\u5b50\u7ec4\u4ef6\u5e76\u63d0\u4f9b\u7a33\u5b9a\u7535\u8def\u5de5\u4f5c\u73af\u5883\u7684\u6838\u5fc3\u7ec4\u6210\u90e8 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"slim_seo":{"title":"What are the processes involved in PCB prototyping? From internal layer traces to solder mask text","description":"What are the processes involved in PCB prototyping? We\u2019ll walk you through each step in detail, starting with the inner layer traces, lamination, drilling, plating through-holes, and applying the first layer of copper, all the way to preparing the outer layer traces. We\u2019ll break it down layer by layer, from the underlying principles to the practical steps, so even beginners can understand."},"_slim_seo_primary_term_category":0,"_slim_seo_primary_term_post_tag":0,"footnotes":""},"categories":[406,26],"tags":[],"class_list":["post-1957","post","type-post","status-publish","format-standard","hentry","category-pcb-manufacturing","category-blog"],"_links":{"self":[{"href":"https:\/\/www.jingpengpcb.com\/en\/wp-json\/wp\/v2\/posts\/1957","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=1957"}],"version-history":[{"count":5,"href":"https:\/\/www.jingpengpcb.com\/en\/wp-json\/wp\/v2\/posts\/1957\/revisions"}],"predecessor-version":[{"id":20062,"href":"https:\/\/www.jingpengpcb.com\/en\/wp-json\/wp\/v2\/posts\/1957\/revisions\/20062"}],"wp:attachment":[{"href":"https:\/\/www.jingpengpcb.com\/en\/wp-json\/wp\/v2\/media?parent=1957"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.jingpengpcb.com\/en\/wp-json\/wp\/v2\/categories?post=1957"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.jingpengpcb.com\/en\/wp-json\/wp\/v2\/tags?post=1957"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}