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Printed circuit board milling
Printed circuit board milling
Printed circuit board milling
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A milled printed circuit board

Printed circuit board milling (also: isolation milling) is the milling process used for removing areas of copper from a sheet of printed circuit board (PCB) material to recreate the pads, signal traces and structures according to patterns from a digital circuit board plan known as a layout file.[1] Similar to the more common and well known chemical PCB etch process, the PCB milling process is subtractive: material is removed to create the electrical isolation and ground planes required. However, unlike the chemical etch process, PCB milling is typically a non-chemical process and as such it can be completed in a typical office or lab environment without exposure to hazardous chemicals. High quality circuit boards can be produced using either process.[2] In the case of PCB milling, the quality of a circuit board is chiefly determined by the system's true, or weighted, milling accuracy and control as well as the condition (sharpness, temper) of the milling bits and their respective feed/rotational speeds. By contrast, in the chemical etch process, the quality of a circuit board depends on the accuracy and/or quality of the mask used to protect the copper from the chemicals and the state of the etching chemicals.[3]

Advantages

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PCB milling has advantages for both prototyping and some special PCB designs. The biggest benefit is that one does not have to use chemicals to produce PCBs.

When creating a prototype, outsourcing a board takes time. An alternative is to make a PCB in-house. Using the wet process, in-house production presents problems with chemicals and disposing thereof. High-resolution boards using the wet process are hard to achieve and still, when done, one still has to drill and eventually cut out the PCB from the base material.

CNC machine prototyping can provide a fast-turnaround board production process without the need for wet processing.[4] If a CNC machine is already used for drilling, this single machine could carry out both parts of the process, drilling and milling. A CNC machine is used to process drilling, milling and cutting.[5]

Many boards that are simple for milling would be very difficult to process by wet etching and manual drilling afterward in a laboratory environment without using top-of-the-line systems that usually cost many times more than CNC milling machines.[6]

In mass production, milling is unlikely to replace etching although the use of CNC is already standard practice for drilling the boards.[citation needed]

Hardware

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A PCB milling system is a single machine that can perform all of the required actions to create a prototype board, with the exception of inserting vias and through hole plating. Most of these machines require only a standard AC mains outlet and a shop-type vacuum cleaner for operation.[citation needed]

Software

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Software for milling PCBs is usually delivered by the CNC machine manufacturer. Most of the packages can be split in two main categories – raster and vector.[7]

Software that produces tool paths using raster calculation method tends to have lower resolution of processing than the vector based software since it relies on the raster information it receives.[8][9]

Mechanical system

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The mechanics behind a PCB milling machine are fairly straightforward and have their roots in CNC milling technology. A PCB milling system is similar to a miniature and highly accurate NC milling table. For machine control, positioning information and machine control commands are sent from the controlling software via a serial port or parallel port connection to the milling machine's on-board controller. The controller is then responsible for driving and monitoring the various positioning components which move the milling head and gantry and control the spindle speed. Spindle speeds can range from 30,000 RPM to 100,000 RPM depending on the milling system, with higher spindle speeds equating to better accuracy. Higher RPM is required as the tool diameter gets smaller.[10] Typically this drive system comprises non-monitored stepper motors for the X/Y axis, an on-off non-monitored solenoid, pneumatic piston or lead screw for the Z-axis, and a DC motor control circuit for spindle speed, none of which provide positional feedback. More advanced systems provide a monitored stepper motor Z-axis drive for greater control during milling and drilling as well as more advanced RF spindle motor control circuits that provide better control over a wider range of speeds.[citation needed]

X and Y-axis control

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For the X and Y-axis drive systems most PCB milling machines use stepper motors that drive a precision lead screw. The lead screw is in turn linked to the gantry or milling head by a special precision machined connection assembly. To maintain correct alignment during milling, the gantry or milling head's direction of travel is guided along using linear or dovetailed bearing(s). Most X/Y drive systems provide user control, via software, of the milling speed, which determines how fast the stepper motors drive their respective axes.[citation needed]

Z-axis control

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Z-axis drive and control are handled in several ways. The first and most common is a simple solenoid that pushes against a spring. When the solenoid is energized it pushes the milling head down against a spring stop that limits the downward travel. The rate of descent as well as the amount of force exerted on the spring stop must be manually set by mechanically adjusting the position of the solenoid's plunger.

The second type of Z-axis control is through the use of a pneumatic cylinder and a software-driven gate valve. Due to the small cylinder size and the amount of air pressure used to drive it there is little range of control between the up and down stops. Both the solenoid and pneumatic system cannot position the head anywhere other than the endpoints, and are therefore useful for only simple 'up/down' milling tasks. The final type of Z-axis control uses a stepper motor that allows the milling head to be moved in small accurate steps up or down. Further, the speed of these steps can be adjusted to allow tool bits to be eased into the board material rather than hammered into it. The depth (number of steps required) as well as the downward/upward speed is under user control via the controlling software.

One of the major challenges with milling PCBs is handling variations in flatness. Since conventional etching techniques rely on optical masks that sit right on the copper layer they can conform to any slight bends in the material so all features are replicated faithfully.

When milling PCBs however, any minute height variations encountered when milling will cause conical bits to either sink deeper (creating a wider cut) or rise off the surface, leaving an uncut section. Before cutting some systems perform height mapping probes across the board to measure height variations and adjust the Z values in the G-code beforehand.[citation needed]

Tooling

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PCBs may be machined with conventional endmills, conical d-bit cutters, and spade mills. D-bits and spade mills are cheap and as they have a small point allow the traces to be close together. Taylor's equation, Vc Tn = C, can predict tool life for a given surface speed.[11]

References

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Printed circuit board milling

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(PCB) milling, also known as isolation milling, is a subtractive fabrication process that mechanically removes excess from a -clad substrate to form conductive traces, pads, and other circuit features according to a predefined layout. This method contrasts with traditional chemical by using physical tools to isolate circuit elements, making it ideal for , small-scale production, and in-house where quick iterations are essential. Typically performed on materials like laminate, the process begins with a digital exported as Gerber or files from software such as or Eagle, followed by securing the board in a CNC for precise removal. The core milling operation involves a rotating or V-shaped cutter that operates at spindle speeds of 10,000–20,000 RPM and feed rates of 100–300 mm/min, with each pass removing approximately 0.1 mm of to achieve minimum line widths as fine as 0.1 mm under optimal . Advanced setups, such as CNC routers with Z-axis depth control and surface mapping, ensure accuracy in contour routing for slots, cutouts, and component recesses, while milling variants employ high-powered beams for non-contact , particularly suited for RF/ applications requiring intricate patterns. Post-milling steps include debris, holes if not integrated, and inspecting for continuity with tools like multimeters to verify electrical integrity before component assembly. Among its advantages, PCB milling eliminates the use of hazardous chemicals, reducing environmental impact and enabling versatile operations like , , and in a single setup, which lowers costs and lead times for prototypes compared to outsourced services. However, it faces limitations in achieving the ultra-fine precision of photolithographic methods for high-volume production and requires regular tool due to wear from materials, potentially restricting its . Despite these challenges, the technique's accessibility with affordable CNC machines has democratized PCB fabrication for hobbyists, educators, and engineers, with desktop prototyping tools becoming widely available in the mid-2000s onward. The history of PCB milling traces back to the adoption of CNC technology in electronics manufacturing during the 1970s, evolving from industrial-scale machines to compact desktop systems that gained popularity among makers and small-scale fabricators starting in the early .

Introduction

Definition and Principles

(PCB) milling is a subtractive fabrication process that utilizes a (CNC) machine to selectively remove excess foil from a -clad substrate, thereby creating the conductive traces, pads, and vias required for electrical connectivity. This method, also known as isolation milling or PCB routing, employs small-diameter end mills or specialized engraving bits to engrave precise patterns directly into the board material, typically laminate, without the use of chemicals. At its core, PCB milling operates on subtractive manufacturing principles, where material is removed from a solid starting form to achieve the desired geometry, in stark contrast to additive techniques that build up layers of material. The process begins with a blank -clad board, and the milling tool carves away unwanted to isolate the circuit pathways, ensuring electrical isolation between traces. Key operational concepts include raster milling, which involves systematic area removal by scanning back and forth across regions to clear large surfaces, and vector milling, which traces the outlines of individual traces and for higher precision in defining fine features. Raster methods offer efficiency for broad clearance but lower resolution due to their pixel-like scanning approach, while vector methods provide superior accuracy by following exact paths, though they may require longer processing times for complex designs. Fundamental parameters governing the milling process include feed rate, the linear speed at which the tool advances through the material (typically 100-500 mm/min for PCB applications), and spindle speed, the rotational velocity of the cutting tool (often 10,000-60,000 RPM to achieve clean cuts in soft foil). These settings directly influence achievable tolerances, with minimum trace widths commonly ranging from 0.1 mm to 0.2 mm, depending on tool diameter and machine precision, enabling prototypes suitable for most low-to-medium density circuits. The physics of removal in PCB milling relies on mechanical shear, where the rotating end mill's s apply shear forces to the ductile foil, fracturing and evacuating material as chips. Maintaining an appropriate chip load—the thickness of material removed per per revolution (around 0.005-0.01 mm/tooth for copper-clad boards)—is critical to prevent tool deflection, excessive heat buildup, or breakage, as insufficient load causes rubbing and wear, while excessive load risks tool failure or poor . This shear-dominated mechanism ensures burr-free edges when optimized, distinguishing milling from chemical processes that dissolve uniformly.

Historical Development

The adaptation of computer (CNC) routers for (PCB) milling emerged in the 1970s, building on industrial machining technologies originally developed for and automotive applications. Early CNC systems, which transitioned from punch-card numerical control to computer-integrated operations during this decade, enabled precise routing of copper-clad boards as an alternative to chemical etching. The first commercial PCB milling machines appeared in the late 1970s and early , pioneered by LPKF Laser & Electronics, founded in 1976 in Garbsen, . Engineer Jürgen Seebach developed the initial mechanical process for PCB production, leading to the introduction of the LPKF 39 system, a CAD/CAM-based for milling prototypes without chemicals. By the , LPKF's ProtoMat series established milling as a viable in-house prototyping method, setting benchmarks for precision drilling and contouring in electronics labs. In the 1990s, PCB milling gained traction among hobbyists through integration with personal computers, leveraging PC-based systems and interfaces for affordable DIY setups. This era saw the rise of software like Eagle for design and G-code generation, allowing enthusiasts to control basic CNC routers for small-scale board fabrication. The 2000s marked the proliferation of affordable desktop CNC machines, such as Roland's Modela MDX series, introduced in 2000, which offered compact, user-friendly options for educational and prototyping environments. A key milestone was the adoption of high-speed spindles reaching 20,000 RPM in entry-level models, dramatically reducing milling times from hours to minutes by enabling finer cuts with minimal burrs. The 2010s brought open-source advancements inspired by the project, originally launched in 2005 but evolving significantly for PCB applications through community-driven designs like belt-driven circuit mills. These low-cost, replicable machines, often built using 3D-printed components, democratized access for makers and researchers. Concurrently, PCB milling shifted from industrial and hobbyist tools to widespread adoption in maker spaces post-2010, where machines like the Roland SRM-20 became staples in collaborative environments for .

Comparison to Traditional Methods

Chemical Etching

Chemical etching is a subtractive technique used in (PCB) fabrication to selectively remove unwanted from a -clad substrate, leaving behind the desired circuit traces protected by a resist . The process involves immersing the masked board in a chemical etchant solution that dissolves exposed through oxidation and dissolution reactions. Common etchants include ferric chloride (FeCl₃) and ((NH₄)₂S₂O₈), with ferric chloride being widely used due to its effectiveness and availability. The etching time typically ranges from 10 to 30 minutes, depending on factors such as thickness—for instance, standard 1 oz/ft² (35 µm)—etchant concentration, temperature, and agitation. The process begins with mask application to define the circuit pattern. A resist material, such as or toner from a laser printer transfer method, is applied to the copper surface to protect areas that will form the traces. involves coating the board with a light-sensitive , exposing it to UV light through a , and developing to remove unexposed areas, while toner transfer uses to adhere printed toner directly as the resist. Once masked, the board is immersed in the etching bath, where the etchant attacks the exposed . For ferric chloride, the primary reaction is: Cu+2FeCl3→CuCl2+2FeCl2\text{Cu} + 2\text{FeCl}_3 \rightarrow \text{CuCl}_2 + 2\text{FeCl}_2 This oxidizes copper to copper(II) chloride while reducing ferric ions to ferrous ions, continuing until the exposed copper is fully dissolved. Agitation of the solution ensures even etching and prevents undercutting. After etching, the board is removed and rinsed thoroughly with water to neutralize and halt the chemical reaction, followed by stripping the resist mask using solvents like acetone for toner or alkaline strippers for photoresist, revealing the final copper traces. Common etchants like ferric chloride and require careful handling due to their corrosive and toxic properties. Ferric chloride produces hazardous fumes, especially when heated, and can cause severe skin burns or eye damage upon contact, necessitating the use of protective gloves, , and ventilation during the process. , while less corrosive, can release gases and irritate respiratory systems. Disposal poses significant environmental challenges, as spent etchants contain dissolved ions and other that can contaminate water sources and soil if not properly neutralized and treated—typically by or professional services—to comply with regulations like those from the EPA. These concerns have driven interest in etchants and adopting greener alternatives in industrial settings to minimize ecological impact.

Other Fabrication Techniques

In addition to subtractive methods like chemical etching and mechanical milling, alternative PCB fabrication techniques encompass additive, laser-based, and hybrid approaches that enable direct deposition, precise material removal, or combined processes for prototyping and production. These methods often prioritize flexibility, reduced waste, and integration with non-planar surfaces, offering options for rapid iteration in electronics design. Additive fabrication techniques build conductive paths directly onto substrates without removing material, contrasting with subtractive processes. Inkjet printing using conductive inks, such as those formulated with silver nanoparticles, deposits patterns layer by layer to form traces with conductivities approaching bulk silver after . This method supports and prototyping on various substrates, achieving line widths as fine as 50-100 µm depending on ink formulation and printer resolution. Aerosol jetting extends this capability for direct-write , atomizing inks into a focused stream for non-contact deposition on 3D surfaces; systems like Optomec's Aerosol Jet technology enable printing of functional circuitry with feature sizes down to 10 µm, suitable for embedding components in complex geometries. Laser-based methods provide high-precision alternatives for both ablation and in PCB fabrication. UV removes copper or substrates selectively for prototyping, offering resolutions of 50-100 µm for microvias and traces, which surpasses typical mechanical milling's 100-200 µm limits by minimizing thermal damage through short-pulse operation. (LDI) projects patterns onto photoresists without masks, enabling fine features for high-density interconnects (HDI) boards. CO₂ , operating at longer wavelengths, are commonly used for substrate cutting and depaneling, providing clean edges on materials with minimal heat-affected zones when optimized for pulse duration. Emerging techniques like 3D-printed PCBs integrate traces directly into structural components via filament extrusion, where conductive filaments are co-extruded with insulators to embed circuitry during printing. This approach supports volumetric electronics with resolutions around 250 µm for traces, though advancements in multi-material printers are pushing toward finer features for applications in wearables and IoT devices. Compared to laser methods' 50-100 µm precision, extrusion-based 3D printing trades resolution for seamless integration but requires post-processing like sintering for optimal conductivity. Hybrid techniques combine subtractive and additive steps to enhance functionality, such as mechanical milling or for vias followed by to fill them with , ensuring reliable interlayer connections in multilayer boards. This process deposits a thin conductive layer before electrolytic buildup, achieving via fills with aspect ratios up to 1:1 while maintaining planarity for subsequent . Such hybrids are particularly useful in prototyping where initial rough milling defines features, and refines electrical performance.

Advantages and Limitations

Key Benefits

Printed circuit board (PCB) milling offers significant accessibility for hobbyists, educators, and small-scale manufacturers due to its compatibility with desktop environments such as garages or laboratories, eliminating the need for chemical handling equipment or darkroom setups. Basic setups, including a compact CNC machine, software, and consumables like end mills, can be assembled for under $1,000, making it feasible for individual or low-budget operations without requiring industrial infrastructure. The process provides high precision and flexibility, enabling the creation of fine features such as traces as narrow as 0.15 mm through controlled mechanical removal of cladding. Unlike chemical , which demands pre-applied masks that complicate revisions, PCB milling supports on-the-fly design modifications directly via software updates to the , facilitating where functional boards can be produced in under an hour. This allows for iterative testing and refinement without minimum order quantities, ideal for custom or small-batch production. From an environmental perspective, PCB milling is a dry mechanical process that avoids the use of hazardous etchants like ferric chloride, thereby eliminating generation and associated disposal challenges. The primary byproduct, copper dust, can be effectively managed through integrated vacuum systems, resulting in minimal environmental impact compared to traditional wet methods.

Challenges and Drawbacks

One significant challenge in printed circuit board (PCB) milling is tool wear, as end mills typically last for only 10-20 boards before requiring replacement due to abrasion from copper and substrate materials. However, advancements in coated carbide end mills have extended tool life by 30–100% compared to uncoated versions as of 2025. Additionally, milling thick copper layers exceeding 2 oz necessitates multiple passes, which accelerates bit degradation and increases processing time. Precision limitations arise from the risk of burrs forming on traces during milling, which can compromise electrical connectivity and require post-processing for removal. Undercuts may also occur due to tool deflection, while overall tolerances are constrained by machine rigidity, often reaching only ±0.1 mm in hobbyist CNC setups. Scalability poses drawbacks for high-volume production, as milling a single board can take hours depending on complexity, compared to minutes for batch chemical processes. This results in higher per-board costs for , with breakeven points typically under 100 boards when amortizing modern equipment expenses. Material constraints further limit PCB milling to single- or double-sided boards, where it excels, but present challenges for multi-layer designs due to alignment difficulties and inability to effectively mill internal layers without specialized equipment. Flexible substrates are particularly problematic, as their pliability leads to inconsistent cuts and potential deformation during the mechanical process.

Hardware Components

CNC Milling Machines

CNC milling machines for printed circuit board (PCB) fabrication range from compact desktop routers suitable for hobbyists and small-scale prototyping to more robust professional gantry mills designed for higher precision and production environments. Desktop models, such as the widely used 3018 series, feature compact frames with work areas typically around 300 mm x 180 mm x 45 mm, making them ideal for milling small PCBs in non-industrial settings. In contrast, professional gantry mills, like those in the LPKF ProtoMat series, employ a gantry-style structure for enhanced stability over larger work envelopes, such as 305 mm x 229 mm for the S64 model and up to 650 mm x 530 mm for the X60. These machines prioritize suitability for PCB work through rigid aluminum or composite frames that minimize vibrations during delicate isolation routing. Core features of PCB-specific CNC machines include positioning systems using or servo motors, with steppers predominant in desktop units for cost-effective open-loop control, while servos in professional models provide closed-loop feedback for superior accuracy and reduced missed steps under varying loads. Enclosures or integrated dust management systems are essential in many designs to contain fine and substrate particles generated during milling, preventing contamination of the machine's mechanics and workspace. Compatibility with GRBL firmware is a standard in desktop routers, enabling straightforward integration with open-source control software for execution on Arduino-based controllers. Key specifications emphasize precision and controlled motion, with X-Y travel speeds typically up to 1000 mm/min to balance efficiency and bit longevity in PCB applications. Rigidity is critical to avoid deflection under cutting forces, achieved in professional gantry mills through features like angular contact bearings and reinforced linear rails, ensuring sub-micron essential for trace isolation without wander. These attributes make such machines well-suited for rapid PCB iteration, often integrating briefly with CAM software for direct Gerber file processing.

Spindles and Motors

In printed circuit board (PCB) milling, the spindle serves as the primary rotational drive mechanism, powering the cutting tool to remove traces from the substrate. Common spindle types include DC brushed and brushless motors, which typically operate at speeds ranging from 10,000 to 60,000 RPM to achieve the precision required for fine features like 0.1 mm traces. These high speeds enable efficient material removal while minimizing burrs, though torque must be sufficient for milling layers. Air-cooled spindles are favored for their simplicity and precision in hobbyist and small-scale PCB milling setups, where integrated fans direct airflow over heat-dissipating fins to maintain stable temperatures during operation. This cooling method prevents that could affect milling accuracy, particularly in prolonged runs exceeding 30 minutes, by keeping spindle bearings below 60°C. Stepper motors, such as the widely used NEMA 17 models, drive the linear axes in PCB milling machines, providing precise positioning for the X-Y table and Z-axis. These motors feature a 0.9° step , allowing for finer resolution than standard 1.8° variants, which supports high-precision motion with microstepping drivers. To ensure smooth motion, they are controlled to maintain constant velocity, avoiding low-speed frequencies around 50-100 Hz that can cause vibrations and inaccuracies in trace routing. Accessories like collets are essential for securely holding milling bits in the spindle, with ER11 collets accommodating shank diameters from 1 to 7 mm to suit various tool sizes used in PCB fabrication. These precision-ground collets, made from , provide runout tolerances under 0.01 mm, ensuring concentric that prevents tool deflection during copper milling. Cooling enhancements, such as auxiliary fans or heat sinks on the motor housing, complement air-cooling systems to mitigate overheating in extended sessions.

Tools and Materials

Milling Bits and End Mills

In (PCB) milling, end mills and specialized milling bits serve as the primary cutting tools for removing cladding to define circuit traces and isolate conductive paths. These tools must balance precision, durability, and efficient material removal, particularly when working with thin layers on non-conductive substrates. Common types include flat end mills, which feature 2 or 3 flutes and are designed for isolation routing to clear between traces while maintaining straight cuts. V-bits, characterized by their tapered, V-shaped tips, are used for and scoring fine lines on surfaces, enabling high-resolution trace definition without excessive material removal. Single-flute end mills are preferred for milling non-ferrous metals like , as their design promotes superior chip evacuation to prevent clogging and heat buildup during operation. These bits are typically constructed from premium submicrograin , selected for its exceptional hardness (HRa 93) and transverse rupture strength (4.0 GPa), which ensure wear resistance when copper foil. Flute geometries are optimized for copper, often incorporating a 15° tapered core for stiffness or angles of 37°–45° to enhance shearing and chip flow. (TiN) coatings are commonly applied to bits to improve and extend tool life under repetitive cutting conditions. Selection criteria emphasize bit diameter, with ranges of 0.2–0.8 mm (such as 1/64" or 1/32") ideal for fine trace isolation to achieve minimum feature sizes without undercutting adjacent conductors. Lifespan varies by usage but typically supports around 40–50 meters of total cut length in before dulling, sufficient for 4–10 boards depending on design complexity, influenced by flute count and quality for sustained performance across multiple boards. Costs generally fall between $5 and $20 per bit, making them economical for prototyping while prioritizing quality for reliability. These tools are chosen to complement standard PCB substrates, ensuring clean cuts through 0.5–1 oz cladding without damaging the underlying material.

PCB Substrates and Copper Cladding

Printed circuit board (PCB) milling relies on specific substrate materials that provide mechanical support and electrical insulation, with FR-4 serving as the industry standard due to its balance of durability, flame retardancy, and machinability. FR-4 consists of a woven glass fiber fabric impregnated with epoxy resin, offering high mechanical strength and thermal stability with a glass transition temperature (Tg) of approximately 130–140°C, making it suitable for both prototyping and production milling where precise cuts are required without excessive brittleness. For low-cost prototyping applications, particularly single-sided boards, FR-1 substrates are an alternative, composed of paper reinforced with phenolic resin, which provides adequate insulation at a dielectric constant of 4.0-5.0 but lower water resistance and heat tolerance (glass transition around 130°C) compared to FR-4. Typical substrate thicknesses for milling range from 0.8 mm to 1.6 mm, with 1.6 mm being the most common for standard two-layer boards to ensure stability during the mechanical removal of copper traces. The cladding on these substrates forms the conductive layer that milling tools isolate into circuits, typically using electrodeposited foil for its cost-effectiveness and adhesion properties in rigid PCBs. This foil, produced via electrodeposition, features a vertical grain structure for strong bonding to the substrate and is available in weights of 1 oz/ft² (approximately 35 μm thick) as the standard for most applications, though 2 oz/ft² (70 μm) is used for higher current-carrying needs. Single-sided cladding is common for simple prototypes in milling setups, while double-sided configurations support more complex interconnects on the same board plane. For milling compatibility, bare surfaces are preferred over finished options like (HASL), as they allow direct tool engagement without solder interference, though HASL can be applied post-milling if required for assembly. Prior to milling, pre-cleaning the copper-clad substrate is essential to remove surface oxides and contaminants that could impair tool performance or cause uneven cuts. This involves rinsing with warm to dislodge grit, followed by scrubbing with an cleanser using a non-metallic to eliminate oxides, and final drying with on a lint-free cloth to ensure a residue-free surface. Milling compatibility also demands attention to heat buildup, as frictional forces can generate localized temperatures exceeding 100°C, potentially causing if is trapped within the substrate layers, which weakens the epoxy-resin bond in and leads to layer separation. To mitigate this, substrates should be stored in low-humidity environments and baked if necessary to drive out absorbed before processing.

Software Tools

PCB Design Software

PCB design software plays a crucial role in preparing layouts for (PCB) milling by enabling the creation of schematics and board designs optimized for subtractive fabrication processes. These tools allow users to define electrical connections, place components, and route traces while adhering to manufacturing constraints specific to CNC milling, such as minimum feature sizes dictated by capabilities. Popular open-source options include , which provides comprehensive through its Eeschema module, supporting hierarchical designs, custom symbols, and electrical rule checking to verify connectivity before proceeding to layout. In 's Pcbnew editor, users perform component placement and trace routing using an interactive router that automates path generation while respecting user-defined constraints, facilitating efficient designs for milling prototypes. Autodesk Eagle offers similar capabilities as a widely adopted tool, featuring integrated and PCB layout environments that seamlessly link electrical diagrams to physical board arrangements. Its board editor supports manual and autorouting for traces, along with libraries for component placement, making it suitable for both hobbyist and professional milling workflows. For milling-specific adaptations, these software packages incorporate design rule checks (DRC) to enforce millable features, such as a minimum clearance of 0.2 mm between traces and pads to account for typical diameters and avoid short circuits during isolation routing. DRC integration ensures compliance with fabrication limits by flagging violations in trace width, via sizing, and spacing, which are critical for generating reliable toolpaths in subsequent steps. The typical workflow begins with to define circuit functionality and component interconnections, followed by import into the PCB layout editor for placement and . Once the layout is complete and verified via DRC, the software exports Gerber files representing layers, soldermask, and data, which serve as input for milling preparation without directly generating . This export format standardizes designs for compatibility with CAM tools tailored to isolation algorithms that isolate traces by milling around them on copper-clad substrates.

CAM and G-code Generation

(CAM) software plays a crucial role in (PCB) milling by translating PCB design files into precise machine instructions for CNC routers. These tools process standard input formats such as Gerber files for copper traces and Excellon files for drill locations, generating output in format compliant with the ISO 6983 standard, which defines preparatory functions () and miscellaneous functions (M-codes) for of machine tools. Popular open-source CAM tools for PCB milling include FlatCAM and pcb2gcode. FlatCAM accepts Gerber and Excellon inputs to create geometry objects representing traces and holes, then generates for isolation and operations. Similarly, pcb2gcode is a command-line tool that converts Gerber files into for isolation, , and , supporting features like filled zone milling for pours. Toolpath generation in these CAM programs involves strategies tailored to PCB fabrication, such as contour-based isolation milling, which creates offset paths around individual traces to electrically isolate them from surrounding , typically using a small (e.g., 0.1-0.2 mm diameter). In contrast, pocket strategies remove larger areas by generating inward spirals or raster patterns, useful for clearing ground planes or non-functional regions to minimize milling time. Users configure parameters like feed rate (200-500 mm/min), spindle speed (10,000-30,000 RPM), and plunge rate (50-100 mm/min) to balance precision, tool life, and material integrity, with adjustments based on bit type and substrate hardness. Optimization techniques enhance efficiency and accuracy, including peck drilling for vias, where the tool retracts periodically (e.g., every 0.5-1 mm depth) to evacuate chips and prevent bit breakage in substrates. CAM software like FlatCAM provides previews, rendering 2D or 3D visualizations of toolpaths to verify coverage and detect potential collisions before execution. For error handling, such as avoiding overcuts that could damage adjacent traces, users set isolation margins (e.g., 0.05 mm) and tool diameter compensation in the CAM settings, ensuring paths stay within design tolerances.

Mechanical Systems

X-Y Axis Movement

In printed circuit board (PCB) milling machines, the X-Y axis movement is responsible for the precise horizontal navigation of the milling tool across the substrate to route traces and create vias. Common mechanisms include lead screws or timing belts coupled to stepper motors, which convert rotational motion into linear displacement along the X and Y directions. Lead screws, often with an 8 mm pitch, provide direct and rigid linear motion suitable for high-precision tasks, while belt drives, such as 2GT timing belts with 2 mm tooth spacing, offer faster traversal with fewer mechanical components but require careful tensioning to maintain accuracy. Homing switches, typically limit switches such as mechanical or optical types positioned at the axes' endpoints, establish the machine's origin by detecting when the gantry reaches a reference position during startup, ensuring consistent starting points for each milling job. Control of X-Y movement relies on stepper motors, commonly NEMA 17 bipolar types with a 1.8° step angle equivalent to 200 full steps per revolution, driven by pulse signals from a or CNC controller. Microstepping subdivides these steps—for instance, 1/16 microstepping yields 3,200 microsteps per revolution—enhancing smoothness and resolution, though actual positioning accuracy under load may degrade to ±0.1 mm without sufficient due to detent effects and friction. Backlash, the play between the drive mechanism and load, is compensated in software by adjusting feed rates or adding corrective offsets, improving but not eliminating mechanical vibrations. Performance metrics emphasize controlled acceleration to prevent and ensure trace integrity; typical ramps reach 100–500 mm/s², balancing speed with stability in small-scale PCB machines. Factors like belt tension directly influence accuracy, with improper settings causing slippage and reducing to ±0.05 mm or worse, while well-tuned lead screw systems in commercial PCB mills achieve ±0.025 mm over short travels.

Z-axis and Depth Control

In printed circuit board (PCB) milling, the Z-axis mechanism typically employs or servo motors to drive vertical movement, enabling precise control over the milling depth to remove cladding without damaging the underlying substrate. motors are commonly used for their cost-effectiveness and open-loop positioning accuracy in hobbyist and small-scale machines, while servo motors provide closed-loop feedback for higher precision and in professional setups, often paired with encoders to monitor position in real time. Limit switches are integrated for homing and end-stop detection, preventing over-travel and ensuring repeatable Z-axis initialization before milling operations. To address substrate flatness variations, which can lead to inconsistent etching depths across the board, auto-leveling probes are employed to map the surface . These probes detect electrical continuity between the milling tool (or a dedicated probe) and the conductive layer, recording Z-height offsets at grid points spaced approximately 1/4 inch apart; the data is then used by software to dynamically adjust the Z-axis during milling. This probing process compensates for imperfections in the PCB or fixturing, maintaining a uniform removal depth through the copper layer. Depth control is achieved through feedback loops that regulate Z-position, with servo systems offering superior responsiveness compared to steppers by correcting deviations via position sensors. Plunge cycles are programmed in small increments, typically 0.1 mm per step, to gradually lower the tool and minimize breakage risk on fragile end mills during initial penetration. These cycles integrate with X-Y axis coordination to ensure smooth transitions into the material. Key challenges in Z-axis operation include deflection under cutting loads, which can cause uneven depths or tool vibration, particularly on longer travels or with harder substrates. Solutions involve using rigid couplers or anti-backlash mechanisms to enhance mechanical stiffness and reduce play between the motor and lead screw. Typical Z-axis travel in PCB milling machines ranges from 50 to 100 , sufficient for standard board thicknesses and multi-layer isolation routing.

Fabrication Process

Preparation and Setup

Preparation for (PCB) milling begins with securing the substrate to ensure stability during the process. The copper-clad board is typically cut to size with a small margin and cleaned using and a lint-free cloth to remove contaminants that could affect or milling accuracy. For fixturing, the substrate is mounted flat onto the machine bed using , often reinforced with (CA) glue for enhanced hold without causing bowing, or a vacuum table for uniform pressure distribution. In double-sided milling, alignment is critical; fiducials—small reference marks created at the board's corners via or —are used to register the board's position when flipping, allowing the machine's camera or probe to and center for precise overlay. Mechanical alignment methods employ dowel pins, typically 2–3 mm in diameter for optimal balance on hobby machines, inserted into alignment holes drilled 0.05–0.1 mm larger than the pins, such as h6 tolerance 3 mm pins (2.998–3.000 mm diameter). While larger diameters improve rigidity and reduce board shift or rotation during flipping, optimal accuracy depends more on the machine's spindle runout and repeatability (typically 0.05–0.1 mm on models like the 3018); smaller pins provide better relative precision as larger holes can amplify drilling errors. This setup achieves a slip fit enabling easy insertion without binding while compensating for drilling inaccuracies, spindle non-perpendicularity, and flip positioning errors prevalent in hobby CNC machines like the 3018. Parameter setting involves tuning machine variables based on properties and tool specifications to achieve clean isolation routing without damaging the substrate. Chipload, the thickness of removed per , is calculated as feed rate divided by (spindle RPM multiplied by number of flutes), with recommended values for PCB copper cladding typically ranging from 0.01 to 0.03 mm/ to balance precision and tool life; for example, at 10,000 RPM and a single-flute V-bit, a feed rate of 100 mm/min yields a chipload of 0.01 mm/. Plunge rates are set lower, around 30-60 mm/min, to prevent bit deflection, while spindle speeds often reach 10,000-35,000 RPM for fine end mills or V-bits (0.1-0.3 mm tip). Tool follows, including verifying bit installation in the tool magazine and generating a via probing a grid (e.g., 3x3 points at 1 cm spacing) to compensate for any substrate irregularities. Safety measures are essential due to the generation of fine copper and fiberglass particles during milling. A dust collection system, such as a vacuum with HEPA filtration, must be attached to the spindle or enclosure to capture debris and prevent inhalation, as fiberglass dust can irritate respiratory tissues despite not being carcinogenic. Workspace preparation includes leveling the machine bed to a variance of less than 0.1 mm across the work area, achieved by shimming the frame or using software-based auto-leveling to maintain consistent Z-depth; protective gear like goggles and gloves is worn, and a dry run without the tool is performed to verify paths.

Milling Execution

Once the G-code file is loaded into the CNC controller software, such as through a sender like Universal Gcode Sender, the milling execution begins by homing the machine axes and starting the program to initiate the tool paths. These paths typically follow either vector routing for precise isolation around traces, where the end mill follows the outline of conductive paths to remove surrounding copper, or raster patterns for broader area clearance, involving parallel linear sweeps to etch away larger copper regions efficiently. To achieve the required depth without overloading the tool, multi-pass strategies are employed, with each pass removing a small increment of material, such as 0.2 mm, particularly for deeper cuts like board outlining or slotting. For example, when milling a thick 4.5 mm PCB board, parameters include a spindle speed of 20,000-40,000 RPM (kept low to minimize heat generation); a feed speed of 0.3-0.8 m/min (slow to reduce vibration); jump routing depth of 0.5-1.0 mm per pass in multiple passes to avoid delamination; and retaining 0.2-0.3 mm tabs for controlled separation. During execution, operators monitor the process in real-time for issues like excessive vibration, which can indicate improper feed rates or tool imbalance, necessitating pauses to adjust parameters such as spindle speed or depth incrementally. Tool changes, if required for different operations like switching from a V-bit for traces to a larger for , are commanded via instructions such as M6 T1, allowing the machine to pause safely. For a standard 100 cm² board, the full milling cycle typically takes 15 to , depending on complexity, trace density, and feed rates around 20-150 mm/min. Troubleshooting during milling focuses on common interruptions like stalls, often caused by dull bits that fail to cut cleanly or by misalignment from board flex or improper fixturing, requiring immediate inspection, bit replacement, and re-zeroing of the Z-axis. In severe cases, such as detected overheating or path deviations, stop buttons or software commands (e.g., for program halt) are activated to prevent damage, followed by a full restart after corrections.

Post-milling Finishing

After the milling process, the PCB undergoes to remove debris and ensure a reliable surface for subsequent steps. Burrs formed along milled edges and traces are typically removed using depaneling tools, fine files, or abrasive pads to prevent electrical shorts or mechanical issues during handling. dust and milling residue are then ed away, often with a shop vacuum equipped with a fine filter to capture small particles without scattering them. Optional light sanding with fine-grit sandpaper (e.g., 400-600 grit) can further smooth edges, improving and , though care must be taken to avoid damaging traces. (IPA) wipes may follow to degrease the board, ensuring no contaminants remain that could affect conductivity. Inspection follows cleaning to verify the integrity of the milled board. Visual examination under magnification (e.g., 10x or ) checks for incomplete cuts, burr remnants, or trace damage that could compromise performance. A in continuity mode tests for opens by probing between connected pads, confirming low resistance (typically under 1 ) along intended traces, while mode or resistance settings detect unintended shorts between adjacent conductors. These checks ensure electrical connectivity and isolate defects early, with pass criteria often defined by design specifications for prototyping reliability. For basic assembly preparation, enhancements like drilling vias and applying may be performed if required by the design. Vias, essential for multi-layer connections or jumper points in single-layer prototypes, are drilled manually with a and bits or via the CNC machine using smaller end mills (0.3-0.8 mm diameter) for precision alignment. , a protective layer, can be applied via , spray coating, or UV-curable methods to insulate traces and prevent oxidation, though it is frequently omitted in to save time and cost. When used, the mask is cured under UV light or heat, leaving exposed pads for .

Prototyping and Small Runs

Printed circuit board (PCB) milling is particularly suited for in laboratories, where processes require quick fabrication of custom boards to test circuit functionality and layout revisions. In university settings, such as the University of Maryland's Terrapin Works, the LPKF ProtoMat S64 enables in-house prototyping by providing high-speed and reliable milling for small-scale electronic projects, allowing researchers and students to produce prototypes without external dependencies. Similarly, the University of South Florida's Rapid Experimentation Lab utilizes desktop milling machines alongside laser structuring to facilitate swift and precise electronic prototyping, supporting interdisciplinary applications in and applied sciences. At , the LEAP facility employs the LPKF S104 for subtractive milling of PCBs with features as small as 0.1 mm, accelerating the transition from design to testable hardware in and research. A notable case study involves the in-house milling of Arduino shields, which exemplify how PCB milling supports modular prototyping for embedded systems. The VirtualWire system, developed at KAIST, allows users to design and simulate circuits on a virtual breadboard before exporting layouts for milling into Arduino-compatible shields using standard copper substrates and desktop CNC tools. This approach enables direct component transfer from breadboard to milled PCB, reducing prototyping time and errors in applications like oscillator circuits, as demonstrated in empirical evaluations where shields were fabricated via milling for immediate functionality testing. For small production runs of 10 to 50 boards, PCB milling offers economic viability, especially for startups developing custom (IoT) devices that demand tailored layouts without high-volume commitments. In-house milling with desktop CNC machines is generally more cost-effective than outsourced fabrication services for low quantities. This cost efficiency is particularly beneficial for IoT prototypes, where startups iterate on compact, sensor-integrated boards for applications like wearable monitors or environmental sensors, enabling faster market validation without substantial upfront investments. Practical examples of PCB milling in prototyping and small runs abound in community and educational contexts. At events like Maker Faire , open-source desktop mills such as the CNC demonstrate accessible PCB fabrication, using 3D-printed components and Gerber file inputs to produce custom boards on-site for hobbyists and makers experimenting with interactive . In university education, institutions like the University of Southern California's Shen Lab employ desktop milling for teaching PCB design through hands-on projects, such as fabricating microdevices for biomedical research, as detailed in studies on cost-effective micromilling platforms that enhance student learning in circuit layout and precision manufacturing. Similarly, California State University Maritime Academy integrates Bantam Tools desktop mills into courses, where students mill compact PCBs for projects like LED helmets and inverted pendulums, fostering skills in and professional-grade prototyping. These applications highlight PCB milling's role in democratizing development across hobbyist gatherings and academic programs.

Emerging Technologies

Recent advancements in printed circuit board (PCB) milling are leveraging (AI) to optimize toolpaths, significantly enhancing efficiency. AI algorithms, such as optimization, have been applied to general CNC drilling operations, with potential to reduce non-productive travel time in PCB contexts. Similarly, integrated AI systems like SenseNC in NX CAM software simulate general machining processes to adjust feed rates and spindle speeds, offering improvements that could benefit PCB milling through reduced . These optimizations are particularly valuable for PCB milling, where precision and speed are critical for prototyping intricate traces. As of 2025, AI-driven tools for automated Gerber file optimization and in desktop PCB mills have further improved prototyping workflows. Hybrid manufacturing approaches are emerging to integrate PCB milling with additive processes, enabling the creation of embedded electronic systems. Techniques like Prinjection allow conventional PCBs to be embedded directly into 3D-printed objects using (FFF) printers, facilitating seamless integration of circuitry within structural components. Hybrid additive manufacturing combines digital light projection with 3D micro-dispensing to produce fully 3D-printed electronic assemblies, including PCBs and passive components, for applications requiring conformal . Complementing these, high-speed milling spindles operating at up to 50,000 RPM enable finer feature resolutions below 50 µm in advanced desktop systems. Open-source software is driving accessible advancements in PCB milling workflows. Tools like FlatCAM provide free, open-source CAM capabilities for generating from Gerber files, supporting CNC routers in producing prototypes with enhanced isolation routing and accuracy. Integration with , an open-source PCB design suite, streamlines the transition from to milled boards, fostering community-driven innovations in hobbyist and educational settings. Sustainability efforts emphasize recyclable materials and waste minimization; for instance, iterative reuse of PCB substrates through reduces material consumption, while eco-friendly practices in CNC milling include metal scraps from end mills and chips to lower environmental impact. Potential for multi-layer PCB milling is advancing through automated systems that handle structuring, , and . LPKF's ProtoMat series features automatic tool changers and fiducial alignment cameras for precise milling of up to eight layers, followed by hydraulic in the MultiPress S4 with vacuum-assisted stacking to ensure uniform pressure and temperature control. Chemical-free through-hole via ProConduct further enables reliable interconnections without galvanic processes for prototypes up to four layers, paving the way for efficient in-house multi-layer fabrication.

References

  1. https://www.elepcb.com/blog/what-is-pcb-milling-in-pcb-fabrication/
  2. https://www.protoexpress.com/kb/pcb-milling/
  3. https://medium.com/cnc-life/history-of-cnc-machining-part-3-from-the-factory-floor-to-the-desktop-b16cc35ef7be
  4. https://www.rapiddirect.com/blog/cnc-history/
  5. https://vlab.amrita.edu/?sub=3&brch=106&sim=241&cnt=1
  6. https://www.pcbway.com/pcb_prototype/PCB_Milling.html
  7. https://www.technotronix.us/pcbblog/the-complete-guide-on-pcb-milling-in-circuit-board-fabrication/
  8. https://www.pcbgogo.com/blog/What_Is_PCB_Milling_in_Your_PCB_Fabrication_.html
  9. https://support.bantamtools.com/hc/en-us/articles/115003453943-Design-Considerations-for-the-Bantam-Tools-Desktop-PCB-Milling-Machine
  10. https://www.pcbway.com/capabilities.html
  11. https://www.precisebits.com/applications/pcbtools.htm
  12. https://www.moresuperhard.com/Blogs/How_to_choose_cutting_tool_for_machining_PCB_board.html
  13. https://www.conturo.com/post/an-in-depth-look-at-how-cnc-machines-work
  14. https://cncrapid.com/the-history-and-development-of-cnc-machine.html
  15. https://www.lpkf.com/en/company/company-profile
  16. https://www.lpkfusa.com/about-lpkf
  17. https://www.rolanddga.com/support/products/milling/modela-mdx-40-3d-milling-machine
  18. https://www.cnczone.com/forums/uncategorised-metalworking-machines/1334-cnc.html
  19. https://reprap.org/wiki/PCB_Milling
  20. https://www.mdpi.com/2411-5134/3/3/64
  21. http://wiki.makespace.org/PCB_milling
  22. https://www.wevolver.com/article/pcb-etching-complete-process-guide-best-practices
  23. https://www.allpcb.com/blog/pcb-manufacturing/the-ultimate-guide-to-pcb-etching-from-design-to-perfect-circuits.html
  24. https://www.bestpcbs.com/blog/2025/06/how-does-pcb-etching-process-work/
  25. https://www.protoexpress.com/blog/wet-pcb-etching-acidic-alkaline-methods/
  26. https://rfpcb.org/pcb-ferric-chloride-tips/
  27. https://www.allpcb.com/blog/pcb-manufacturing/choosing-the-right-etchant-ferric-chloride-vs-cupric-chloride-for-pcb-fabrication.html
  28. https://alliancechemical.com/blogs/articles/old-school-cool-pcb-etching-ferric-chloride
  29. https://www.jlcpcb.com/blog/pcb-etching-techniques-advancements
  30. https://www.xinketching.com/pcb-etching-solutions/
  31. https://www.smidacn.com/a-pcb-etching-machines-and-their-environmental-impact.html
  32. https://www.sciencedirect.com/science/article/pii/S2590123022004005
  33. https://pmc.ncbi.nlm.nih.gov/articles/PMC4714735/
  34. https://pubs.acs.org/doi/10.1021/acsami.6b14787
  35. https://optomec.com/printed-electronics/aerosol-jet-technology/
  36. https://www.circuitinsight.com/pdf/aerosol_jet_printing_electronics_smta.pdf
  37. https://www.allpcb.com/blog/pcb-manufacturing/laser-drilling-vs-mechanical-drilling.html
  38. https://www.protoexpress.com/blog/laser-direct-imaging-sharp-precise-technology/
  39. https://www.coherent.com/web-resources/white-paper/pcb-depaneling-avia-lx-wp
  40. https://laser-depaneling.lpkf.com/en/technology/about-laser-depaneling
  41. https://people.duke.edu/~bjw24/Publication86.pdf
  42. https://pcbtrace.com/what-are-3-d-printed-pcbs/
  43. https://www.protoexpress.com/blog/via-filling-techniques-designers-need-to-know-for-pcb-fabrication/
  44. https://www.epectec.com/pcb/via-filling-process.html
  45. https://hackaday.com/2018/01/04/guide-why-etch-when-you-can-mill/
  46. https://www.makera.com/blogs/article/are-milling-pcbs-finally-the-future-of-electronic-prototyping
  47. https://www.globalwellpcba.com/what-is-pcb-milling/
  48. https://community.carbide3d.com/t/pcb-milling-feeds-and-speeds-tool-wear-ect/69347
  49. https://www.hiboo-tools.com/What-is-the-service-life-of-a-carbide-end-mill-id48778196.html
  50. https://www.digikey.com/en/maker/blogs/2024/deep-dive-into-pcb-manufacturing-techniques-milling
  51. https://www.protolabs.com/resources/design-tips/fine-tuning-tolerances-for-cnc-machined-parts/
  52. https://electronics.stackexchange.com/questions/145311/pcb-etching-chemical-method-or-milling
  53. https://www.guanglijin.com/top-5-desktop-cnc-machines-for-precision-hobbyists-2025-guide/
  54. https://peer.asee.org/a-closer-look-at-printed-circuit-board-milling.pdf
  55. https://www.lunyeecnc.com/products/lunyee-3018-pro-max-cnc-router-laser-2-in-1-machine
  56. https://www.lpkf.com/en/industries-technologies/research-in-house-pcb-prototyping/products/lpkf-protomat-s64
  57. https://www.solectro.se/archive/documents/produktblad/x_serie.pdf
  58. https://www.kebamerica.com/blog/stepper-vs-servo-motor-tradeoffs/
  59. https://www.cnczone.com/forums/milling/391138-cnc-posts.html
  60. https://www.cnccookbook.com/how-to-use-grbl-in-your-cnc-machine-for-2023/
  61. https://support.bantamtools.com/hc/en-us/articles/115001672214-Bantam-Tools-Desktop-PCB-Milling-Machine-Specifications
  62. https://shop.carbide3d.com/products/nomad-3
  63. https://www.lpkf.com/en/industries-technologies/research-in-house-pcb-prototyping/products/lpkf-protomat-e44
  64. https://www.gmnusa.com/boost-machine-efficiency-with-spindle-cooling-systems/
  65. https://www.shopsabre.com/air-cooled-spindle-vs-water-cooled-spindle-in-cnc-work/
  66. https://www.zyltech.com/high-accuracy-0-9-step-angle-nema-17-stepper-motor-1-7-a-0-52-nm-74-ozin/
  67. https://www.omc-stepperonline.com/nema-17-bipolar-0-9deg-36ncm-51oz-in-0-9a-5-4v-42x42x40mm-4-wires-17hm15-0904s
  68. https://www.sikkacollets.com/er11-collet/
  69. https://www.kyoceraprecisiontools.com/pcb/end-mills/
  70. https://www.precisebits.com/products/carbidebits/tapered_stub_125.asp
  71. https://solutions.travers.com/metalworking-machining/milling/the-pros-cons-of-high-and-low-helix-angles
  72. https://www.amazon.com/Single-Tungsten-Carbide-Milling-Cutter/dp/B09LTSMGLQ
  73. https://sterc.org/pdf/other/0437.pdf.pdf
  74. https://bantamtools.com/products/electronics-bit-bundle
  75. https://www.amazon.com/pcb-milling-bits/s?k=pcb%2Bmilling%2Bbits
  76. https://www.protoexpress.com/kb/pcb-substrates/
  77. https://www.bestpcbs.com/blog/2024/07/what-is-tg-meaning-in-fr4-pcb-best-technology/
  78. https://www.nextpcb.com/blog/fr-1-pcb
  79. https://jlcpcb.com/blog/how-to-choose-the-thickness-of-pcb-
  80. https://www.protoexpress.com/kb/copper-for-pcbs/
  81. https://www.protoexpress.com/kb/types-of-circuit-board-surface-finishes/
  82. https://www.pcbway.com/blog/Engineering_Technical/Cleaning_Copperclad_Substrates.html
  83. https://www.candorind.com/pcb-delamination-causes-cures/
  84. https://www.protoexpress.com/blog/how-to-set-up-design-rules-kicad/
  85. https://www.kicad.org/discover/eeschema/
  86. https://www.kicad.org/discover/pcbnew/
  87. https://www.autodesk.com/products/eagle/overview
  88. https://learn.sparkfun.com/tutorials/using-eagle-schematic/all
  89. http://docs.oshpark.com/design-tools/kicad/kicad-design-rules/
  90. https://www.kicad.org/
  91. https://www.nextpcb.com/helpcenter/nextpcb-gerber-from-kicad
  92. https://jlcpcb.com/help/article/How-to-Generate-Gerber-and-Drill-Files-in-Autodesk-Eagle
  93. http://flatcam.org/manual/basics.html
  94. https://www.softguide.com/function/din-66025-iso-6983
  95. https://github.com/pcb2gcode/pcb2gcode
  96. http://flatcam.org/manual/index.html
  97. http://flatcam.org/manual/iso.html
  98. https://www.cnczone.com/forums/pcb-milling/359678-cutting-drilling-pcb-0-8mm-end-mill.html
  99. http://flatcam.org/manual/objectreference.html
  100. https://www.sciencedirect.com/science/article/pii/S2468067220300079
  101. https://jlcpcb.com/blog/pcb-milling-for-prototyping
  102. https://www.cnccookbook.com/home-switch-and-cnc-limit-switch-easy-accurate-and-inexpensive/
  103. https://hackaday.com/2016/08/29/how-accurate-is-microstepping-really/
  104. https://machmotion.com/blog/what-is-backlash-and-how-to-correct-it/
  105. https://www.cabelpiu-viscom.it/pdf/vhf_CNC_Milling_machines_2015.pdf
  106. https://docs.saulstudio.ie/fab-lab-handbook/machines/bantam-mill.html
  107. https://ijsdr.org/papers/IJSDR2504208.pdf
  108. http://iosrjen.org/Papers/Conf.19018-2019/EXTC/Volume-11/11.%252038-40.pdf
  109. https://kuwaitjournals.org/jer/index.php/JER/article/view/12425/2815
  110. https://hobbycnc.com/homepage/pc_board_isolation_routing/pc-board-isolation-routing-autolevel/
  111. https://www.re-innovation.co.uk/blog/2013/milling-pcbs-on-a-cnc/
  112. https://www.raypcb.com/teach-you-how-to-make-pcb-milling-boards-step-by-step/
  113. https://www.instructables.com/Milling-Printed-Circuit-Boards-PCBs-on-a-Cheap-CNC/
  114. https://wiki.nanofab.usc.edu/index.php/LPKF_Standard_Operating_Procedure
  115. https://www.engineersedge.com/dowel_pin.htm
  116. https://www.eevblog.com/forum/reviews/home-made-two-sided-pcbs-alignment-techniques/
  117. https://www.cnczone.com/forums/benchtop-machines/111663-suggested-feed-speed-pcb-cutting-new-post.html
  118. https://www.instructables.com/Custom-PCBs-on-a-CNC-Router/
  119. https://www.precisebits.com/products/carbidebits/scoreengrave.asp
  120. https://www.allpcb.com/blog/pcb-design/tab-routing-masterclass-optimizing-breakaway-tabs-for-clean-pcb-separation.html
  121. https://thentrythis.org/notes/2018/10/29/making-circuit-boards-cnc-machine/
  122. https://support.bantamtools.com/hc/en-us/articles/115001656253-Troubleshooting
  123. https://www.pcb-hero.com/blogs/lickys-column/how-to-cnc-your-pcb-prototype-board
  124. https://support.bantamtools.com/hc/en-us/articles/360052500834-Cleaning-Maintenance
  125. https://optimatech.net/using-a-multi-meter-to-test-a-pcb/
  126. https://www.pcbasic.com/blog/how-to-test-a-circuit-board-with-a-multimeter.html
  127. https://www.lpkf.com/en/industries-technologies/research-in-house-pcb-prototyping/process-steps-for-pcb-prototyping/pcb-drilling
  128. https://www.fscircuits.com/pcb-milling/
  129. https://content.bantamtools.com/blog/soldermask-8gjn4
  130. https://www.fcpcba.com/guide/solder-mask/
  131. https://terrapinworks.umd.edu/equipment/lpkf-pcb-manufacturing
  132. https://www.usf.edu/engineering/iae/about/rel.aspx
  133. https://wne.edu/engineering/leap.cfm
  134. https://make.kaist.ac.kr/files/2021/Lee_VirtualWire_TEI21.pdf
  135. https://uhnf.egr.uh.edu/services/printed-circuit-board/
  136. https://www.kingsunpcb.com/how-much-does-an-iot-devices-pcb-cost/
  137. https://www.youtube.com/watch?v=n0MqTLh_464
  138. http://shenlab.usc.edu/
  139. https://www.csum.edu/web/mycampus/home
  140. https://www.anebon.com/news/ai-algorithms-for-tool-path-optimization-in-cnc-machining/
  141. https://blogs.sw.siemens.com/nx-manufacturing/the-future-of-virtual-toolpath-optimization/
  142. https://www.protoexpress.com/blog/ai-in-pcb-design-and-manufacturing/
  143. https://iopscience.iop.org/article/10.1088/0960-1317/26/10/105005
  144. https://www.guanglijin.com/top-5-pcb-cnc-machines-for-precision-circuit-board-cutting-2025/
  145. http://flatcam.org/
  146. https://smartlab.cs.umd.edu/assets/pdf/pcbrenewal.pdf
  147. https://www.zintilon.com/blog/going-green-with-cnc-machining/
  148. https://www.lpkf.com/en/industries-technologies/research-in-house-pcb-prototyping/multilayer-solutions
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