How Does consumer electronics PCB manufacturer Work?

11 Aug.,2025

 

What is a PCB Manufacturer? The Definitive Guide - JHYPCB

What is a PCB Manufacturer? The Definitive Guide

A PCB manufacturer is a specialized company that fabricates printed circuit boards - the backbone of virtually all electronic devices. This guide explores their roles, manufacturing processes, technologies, and services, helping you understand how to choose the right PCB manufacturing partner.

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What is a PCB Manufacturer? Understanding Their Role and Responsibilities

As an essential part of the electronics manufacturing supply chain, a PCB manufacturer plays a crucial role in producing the backbone of various electronic devices. But what exactly is a PCB manufacturer, and what are their primary responsibilities? Let’s delve into this topic.

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A PCB manufacturer is a company specializing in fabricating printed circuit boards, the foundational components that interconnect and support electronic components in virtually all electronic products. These specialized manufacturers have the expertise, equipment, and processes to transform PCB designs into physical boards that facilitate the integration and functionality of electronic circuits.

The Role of PCB Manufacturers in the Electronics Industry PCB manufacturers are an indispensable link in the electronics production chain. Their intricate work ensures that PCBs meet the stringent requirements for quality, reliability, and performance demanded by various industries, including consumer electronics, telecommunications, aerospace, automotive, and medical devices.

Key Responsibilities of a PCB Manufacturer

  1. PCB Design and Engineering Support
    While PCB manufacturers may not always handle the initial design phase, they often collaborate closely with electronics design teams to ensure the manufacturability and feasibility of PCB layouts. Their expertise in PCB fabrication processes allows them to provide valuable insights and recommendations for optimizing designs.
  2. PCB Fabrication and Production
    The core responsibility of a PCB manufacturer is to fabricate printed circuit boards according to client specifications and designs. This process involves multiple stages, including imaging, etching, drilling, plating, and final finishing. Manufacturers must adhere to strict quality control measures to ensure the boards meet industry standards and customer requirements.
  3. PCB Testing and Inspection
    Quality assurance is paramount in the PCB manufacturing process. Manufacturers conduct rigorous testing and inspection procedures to verify the fabricated PCBs’ functionality, electrical integrity, and physical characteristics. This step is crucial for identifying and addressing any potential defects or issues before the boards are integrated into final products.
  4. Supply Chain Management and Logistics
    Efficient supply chain management is another key responsibility of PCB manufacturers. They must coordinate the procurement of raw materials, manage inventory levels, and ensure timely delivery of finished PCBs to their customers, often adhering to strict production schedules and lead times.

By understanding the role and responsibilities of a PCB manufacturer, businesses and individuals can better appreciate the vital contribution these specialized companies make to the electronics industry. Choosing a reputable and capable PCB manufacturer is essential for ensuring electronic product quality, reliability, and successful integration.

The Intricate Process of PCB Manufacturing: A Closer Look

A PCB, a marvel of engineering and precision manufacturing, is at the heart of every electronic device. To understand the capabilities of a PCB manufacturer, it’s essential to delve into the intricate process they follow to transform PCB designs into functional reality.

  1. PCB Design
    The PCB manufacturing process begins with the design phase, where electronic engineers create detailed schematics and layouts using specialized CAD software. These designs not only specify the placement of components but also define the intricate network of copper traces that will interconnect them.
  2. PCB Fabrication
    Once the design is finalized, the PCB fabrication process commences. This multi-step procedure involves several critical stages:
    a. Imaging: The PCB design is transferred onto a photosensitive layer applied to a copper-clad laminate using advanced imaging techniques, such as direct imaging or photolithography.
    b. Etching: The exposed areas of the copper layer are selectively removed through chemical etching, leaving behind the desired circuit patterns.
    c. Drilling: Precise holes are drilled into the board to accommodate component leads and create vias (conductive pathways between layers) for multilayer PCBs.
    d. Plating: Copper or other conductive materials are electroplated onto the drilled holes and circuit patterns to enhance conductivity and facilitate component mounting.
    e. Solder Masking: A protective solder mask layer is applied to the PCB, leaving only the necessary areas exposed for component soldering.
  3. PCB Testing and Inspection
    Quality assurance is a paramount concern for PCB manufacturers. After fabrication, the boards undergo rigorous testing and inspection processes to ensure compliance with design specifications and industry standards. Electrical testing, visual inspection, and advanced techniques like AOI are employed to identify and rectify any defects or anomalies.
  4. PCB Assembly (Optional)
    While some PCB manufacturers focus solely on bare board fabrication, others offer additional assembly services. This involves mounting and soldering electronic components onto the PCB, either through manual or automated processes, resulting in a fully assembled and functional circuit board.

Throughout this intricate process, PCB manufacturers must maintain strict quality control measures, adhere to industry regulations, and implement best practices to ensure the highest levels of precision, reliability, and performance in the final product.

By understanding the PCB manufacturing process, businesses can better appreciate the complexity and attention to detail required by PCB manufacturers to deliver high-quality boards that form the backbone of modern electronics.

Learn more about the PCB fabrication process:

  • Navigating the PCB Manufacturing Process Part 1: Unveiling MI, Cutting, and Drilling
  • Navigating The PCB Manufacturing Process Part 2: Copper Plating, Routing
  • Navigating The PCB Manufacturing Process Part 3: Pattern And AOI
  • Navigating The PCB Manufacturing Process Part 4: Solder Mask, Silkscreen, Surface Finish
  • Navigating The PCB Manufacturing Process Part 5: Testing, V-cut, QC, And Shipping

Cutting-Edge Technologies Powering PCB Manufacturing

The PCB manufacturing industry is a constantly evolving landscape, driven by advancements in technology and the ever-increasing demand for smaller, more complex, and higher-performing electronic devices. To meet these demands, PCB manufacturers continuously invest in and adopt cutting-edge technologies that enable them to push the boundaries of what’s possible.

  1. PCB Fabrication Technologies
    Direct Imaging: Direct imaging technology has revolutionized the PCB imaging process by using highly focused laser beams or UV light sources to directly transfer the circuit patterns onto the photosensitive layer, eliminating the need for photomasks and improving accuracy.

    Advanced Etching Processes: Manufacturers employ various advanced etching techniques, such as plasma etching and laser etching, to achieve finer circuit features and better dimensional control, enabling the production of HDI PCBs.
  2. PCB Material Innovations
    a. High-Performance Laminates: The development of high-performance laminates, such as low-loss materials, thermal-resistant materials, and flexible circuit materials, has enabled the production of PCBs for specialized applications, including high-frequency communications, automotive electronics, and wearable devices.
    b. Conductive Materials: Advances in conductive materials, like copper foils and conductive pastes, have improved signal integrity, power delivery, and thermal management capabilities of PCBs, allowing for higher-speed data transfer and better heat dissipation.
  3. PCB Testing and Inspection Technologies
    a. AOI: AOI systems use advanced imaging technologies and algorithms to automatically inspect PCBs for defects, such as shorts, opens, misalignments, and component placement errors, ensuring a high level of quality control.
    b. Electrical Testing: Manufacturers employ various electrical testing methods, including flying probe testers, in-circuit testers, and boundary scan testing, to verify the functionality and electrical integrity of PCBs, identifying and isolating potential issues before final assembly.
  4. Precision Manufacturing Techniques
    a. Laser Depaneling: Laser depaneling technology enables precise separation of individual PCBs from larger panels, reducing stress and potential damage compared to traditional mechanical routing methods.
    b. Automated Assembly Lines: Highly automated assembly lines, equipped with advanced pick-and-place machines and reflow soldering systems, allow for efficient and accurate component mounting and soldering, ensuring consistent quality and high throughput.

By embracing and mastering these cutting-edge technologies, PCB manufacturers can deliver innovative solutions that meet the ever-evolving demands of the electronics industry. From miniaturization and increased complexity to improved performance and reliability, these advanced technologies are shaping the future of PCB manufacturing and enabling the development of next-generation electronic devices.

The Comprehensive Service Offerings of a PCB Manufacturer

As the backbone of electronic devices, PCBs are essential components that require precision manufacturing and specialized expertise. PCB manufacturers offer a wide range of services to cater to the diverse needs of their clients, from large-scale production runs to custom prototyping solutions.

  1. Standard PCB Production
    One of the core services PCB manufacturers provide is the production of standard PCBs in various sizes, layer counts, and materials. These boards are commonly used in consumer electronics, industrial control systems, and telecommunication equipment. Manufacturers employ advanced fabrication techniques and stringent quality control measures to ensure consistent performance and reliability.
  2. High-End PCB Manufacturing
    As technology advances, the demand for high-performance PCBs has grown significantly. PCB manufacturers offer specialized services for producing HDI PCBs, rigid-flex PCBs, and other advanced PCB board types. These boards are essential for applications that require high-speed data transfer, compact form factors, and exceptional thermal management, such as in the aerospace, defense, and medical industries.
  3. Small Batch and Prototype PCB Services
    In addition to large-scale PCB production, many PCB manufacturers provide small batch and PCB prototyping services to cater to the needs of product development teams, hobbyists, and businesses with low-volume requirements. These services allow clients to quickly and cost-effectively produce small quantities of PCBs for testing, evaluation, and early-stage product development.

    PCB Prototyping: PCB Prototyping services enable clients to quickly iterate and refine their PCB designs before committing to full-scale production. Manufacturers use specialized equipment and techniques to produce high-quality PCB prototypes, often with quick turnaround times.

    Low-Volume PCB Production: For projects with limited production runs or small batch requirements, PCB manufacturers offer low-volume PCB production services, ensuring the same level of quality and precision as larger-scale operations.
  4. Product Development and Technical Support
    Many PCB manufacturers offer comprehensive product development and technical support beyond fabrication services. Their teams of experienced engineers collaborate with clients to optimize PCB designs, provide manufacturing feasibility analysis, and suggest improvements to enhance performance, reliability, and manufacturability.

By offering a comprehensive range of services, PCB manufacturers position themselves as trusted partners for businesses across various industries, from startups and hobbyists to established electronics companies. Their expertise, advanced capabilities, and commitment to quality enable them to deliver reliable and high-performing PCBs that form the foundation of innovative electronic products.

Choosing the Right PCB Manufacturer: Key Considerations

In the ever-evolving electronics industry, partnering with a reliable and capable PCB manufacturer is crucial for ensuring the success of your electronic products. With a multitude of options available, selecting the right PCB manufacturing partner requires careful evaluation of several key factors.

  1. Technical Expertise and Capabilities
    Their technical expertise and manufacturing capabilities should be a top priority when assessing potential PCB manufacturers. Look for manufacturers with a proven track record in producing high-quality PCBs for your specific application or industry. Evaluate their experience in handling various board complexities, layer counts, materials, and specialized requirements such as HDI or rigid-flex designs.
  2. Quality Assurance and Certifications
    Quality is paramount in the PCB manufacturing process, as defects or subpar workmanship can significantly impact the performance and reliability of your electronic products. Reputable PCB manufacturers should have robust quality assurance systems in place, including stringent inspection procedures, electrical testing, and adherence to industry standards and certifications (e.g., ISO , IPC-A-600, UL, and RoHS).
  3. Production Capacity and Lead Times
    Consider the PCB manufacturer’s production capacity and lead times to ensure they can meet your volume requirements and delivery schedules. Reliable manufacturers should have the ability to scale up production and offer reasonable lead times, minimizing potential supply chain disruptions or delays in your product development or manufacturing cycles.
  4. Customer Service and Technical Support
    Effective communication and technical support are essential when working with a PCB manufacturer. Evaluate their responsiveness, communication channels, and the availability of dedicated support teams to address your queries, design clarifications, or any issues that may arise during the manufacturing process.
  5. Pricing and Cost-Effectiveness
    While cost should not be the sole determining factor, it is essential to consider the overall value proposition offered by the PCB manufacturer. Compare pricing structures, minimum order quantities, and any additional services or fees. Look for manufacturers that strike a balance between competitive pricing and high-quality standards, ensuring cost-effectiveness without compromising on quality or reliability.
  6. Reputation and Customer Testimonials
    Research the PCB manufacturer’s reputation within the industry by reading customer testimonials, reviews, and case studies. A reputable manufacturer with a strong track record of satisfied clients can provide valuable insights into their capabilities, service quality, and overall customer experience.

By carefully evaluating these key factors, you can increase your chances of finding a PCB manufacturer that aligns with your specific requirements, enabling you to bring high-quality, reliable, and competitive electronic products to market.

Frequently Asked Questions

A PCB manufacturer is a company that specializes in fabricating printed circuit boards – the foundation that interconnects and supports electronic components in virtually all electronic devices.

PCB stands for “Printed Circuit Board.” It refers to the boards made of insulating material with conductive pathways etched onto their surfaces to connect different components.

PCB manufacturers serve a wide range of industries, including consumer electronics, telecommunications, aerospace, automotive, medical devices, and many more. Any industry that involves electronic products or components will likely require PCB manufacturing services.

In manufacturing, PCBs are essential components that provide the physical base and electrical connections for mounting and integrating various electronic components such as chips, capacitors, and resistors to create functional electronic products.

Lead times can vary depending on factors such as order volume, complexity, and the manufacturer’s production capacity. However, for standard PCB orders, lead times typically range from a few days to a couple of weeks. Rush or prototype services may be available for quicker turnaround times.

Yes, many PCB manufacturers offer additional assembly services, including component mounting, soldering, and full system assembly. This can be a convenient one-stop solution for clients seeking turnkey PCB assembly solutions.

Common PCB materials include fiberglass reinforced epoxy laminate (FR4), polyimide, ceramic, and various metal finishes (e.g., copper, tin, gold). The choice of material depends on factors such as electrical performance, thermal management, and application requirements.

Reputable PCB manufacturers follow strict quality control processes, including electrical testing, visual inspection, and compliance with industry standards (e.g., IPC, UL). Additionally, requesting certifications, reviewing customer testimonials, and establishing clear acceptance criteria can help ensure quality.

PCBs are manufactured by specialized companies known as PCB fabricators or PCB manufacturers. These companies have the expertise, equipment, and processes required to produce high-quality PCBs according to client specifications.

PCB manufacturing is the process of fabricating printed circuit boards through a series of steps, including design, imaging, etching, drilling, plating, and final assembly. It involves transforming PCB designs into physical boards ready for component integration.

Conclusion

Understanding the intricate world of PCB manufacturing is crucial for businesses and individuals seeking reliable electronic solutions. This comprehensive guide has explored the roles and responsibilities of PCB manufacturers, delving into their manufacturing processes, cutting-edge technologies, and diverse service offerings. By recognizing the key factors to consider when selecting a PCB manufacturing partner, you can ensure the quality, reliability, and timely delivery of your electronic products. Whether you’re an electronics engineer, product developer, or an enthusiast, this knowledge empowers you to navigate the PCB manufacturing landscape with confidence, enabling you to bring innovative ideas to life.

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PCB Manufacturing Process | Sierra Circuits

How is a PCB manufactured?

The PCB manufacturing process transforms design files such as Gerber/ODB++/IPC-, netlists, and drill files into a physical circuit board.

It begins with product conceptualization, schematic entry, layout design, and production file generation.

The bare board is fabricated once the printed board design files are finalized. Next, the components are assembled on the board, followed by comprehensive functionality testing.

Step-by-step PCB manufacturing process

Step 1: Pre-production engineering

The PCB manufacturing commences after receiving the design files from a PCB designer or an electrical engineer. The files include:

  • Gerber or ODB++ or IPC- files (used for fabrication).
  • Bill of Materials (BOM) (used for assembly).

This stage involves:

  1. DFM checks: It is performed to identify potential errors that might arise during the PCB fabrication process. In case of any errors, the designer/client is alerted about it.
  2. CAM processing: Corrected files are fed into computer-aided manufacturing (CAM) software, which recognizes layer formats, drilling data, and IPC netlists and converts the electronic data into images. It also verifies the layer order sequence, runs design rule checks (DRC), and performs many other operations.
  3. Output file generation: The CAM system generates essential files for manufacturing, including drill program (sub drill and main drill), imaging layers, solder mask file output, route file, and IPC netlist.

Download our eBook to learn how to design a manufacturable PCB.

Design for Manufacturing Handbook

10 Chapters - 40 Pages - 45 Minute Read
What's Inside:
  • Annular rings: avoid drill breakouts
  • Vias: optimize your design
  • Trace width and space: follow the best practices
  • Solder mask and silkscreen: get the must-knows

Step 2: Inner layer imaging

With the increasing miniaturization of electronic components, fabricators primarily rely on laser direct imaging (LDI) for precise circuit patterning.

Here are the steps involved in LDI:

  1. Photoresist application: A layer of photo-sensitive film (photoresist) is applied to the board. This film contains photo-reactive chemicals that undergo polymerization upon exposure to ultraviolet (UV) light.
  2. Laser direct imaging (LDI): The panel is positioned under a computer-controlled laser that selectively hardens the photoresist, forming the desired circuit pattern.
  3. Development and processing: The unhardened (unexposed) photoresist is removed with an alkaline solution, leaving the protected copper intact.

The LDI workflow is shown in the image below:

Step 3: Etching

Etching is a crucial step in the PCB manufacturing process, where the excess copper (non-circuit copper) is removed from the board to reveal the desired circuit pattern.

It typically takes place in a conveyorized develop, etch, and strip line. Here, the board moves through the chamber while being sprayed with the various chemicals to ensure consistent developing and etching to achieve the desired results.

Key parameters to monitor during etching include:

  1. Well-maintained chemistry within the specification.
  2. Panel movement speed
  3. Proper spray pressure and distribution of the chemical solution based on the resist height and the amount of copper to be etched.

Proper control of these factors is essential for achieving precise and clean circuit patterns on the PCB.

Step 4: Photoresist stripping

In this process, the residual photoresist is etched away from the copper surface. The process involves dissolving caustic pellets (chemical agents) in water combined with a high-pressure water rinse, which breaks down and washes away the remaining photoresist.

Step 5: Inspection and post-etch punch

Once all layers are cleaned and prepared, we perform a post-etch punch to ensure precise layer-to-layer registration. Using alignment targets on the inner layers, the boards are placed into an optical punch machine that accurately aligns both the inner and outer layers.

Following this, inspection is carried out through visual scanning of the board surface using an automated optical inspection (AOI) system. The circuit board is illuminated using various light sources, while high-definition cameras capture detailed images. The AOI system then analyzes these images to verify accuracy and detect any defects.

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Step 6: Alternative oxide coating

Here, the copper circuit pattern is coated with an alternative oxide coating, primarily used as an adhesion promoter.  It also helps prevent oxidation and corrosion of copper.

Step 7: Lamination

Lamination is the process of bonding copper foil, prepreg, and inner layer cores under controlled temperature and pressure to form a multilayer PCB.

The lamination process consists of two main steps:

  1. Stack-up preparation: Carefully arranging the layers (copper foil, prepreg, and cores) in a symmetrical configuration.
  2. Bonding: Applying heat and pressure using a mechanical press to fuse the layers together. The bonding is done in two stages: hot pressing and cold pressing.

A computer-controlled bonding press regulates the stack-up heating, pressure application, and controlled cooling of the stack to ensure optimal bonding quality.

Sierra Circuits specializes in high-precision PCB manufacturing in the USA, utilizing advanced tools like X-ray drill machines, mechanical vision drill systems with controlled depth, laser drilling, and Seica FPT machines to ensure the highest precision.

Check out our rigid PCB manufacturing capabilities to learn more.

Step 8: Drilling

During this stage, holes are created for vias and solder leaded components. A computer-controlled X-ray drill is used to accurately locate target points within the inner layers and drill precise registration holes. Operators can select specific drill programs, allowing the machine to position itself accurately along the X-Y coordinates.

The system is capable of drilling holes as small as 125 microns in diameter. The machine automatically selects the drilling parameter for material/stack-up.

Drilling can produce burrs. These are removed during the deburring process, which cleans the surface of the board and eliminates any impurities. Laser drilling is commonly used in high-speed PCB manufacturing to create precise vias that support high-frequency signal performance.

For more, see PCB drilling explained: the dos and don’ts.

Step 9: Metallization of the dielectric

During this step, the walls of the drilled holes are made conductive through electroless copper deposition. It is a chemical process that coats both the hole walls and the panel surface with a thin layer of copper.

Here are the steps involved in the metallization process:

  1. Surface preparation and cleaning: The PCB panel undergoes a thorough chemical de-smear process to remove the possibility of any epoxy smear from the hole walls, debris, and oxidation from the hole walls and surface. Plasma is also used for various types of de-smear, etch back, and activation processes.
  2. Catalyst activation: A palladium-based catalyst is used to initiate an electroless deposition process.
  3. Electroless copper deposition: The panel is immersed in an electroless copper bath where a controlled auto-catalytic reaction deposits a uniform copper layer on the hole walls as well as the surface of the panel. According to IPC class 2 requirements, the final copper thickness (after plating) in vias must be at least 0. inches (20 microns).
  4. Coverage: The thin copper coating forms a continuous conductive layer along the hole walls and over the surface, enabling subsequent electroplating and circuit formation.

Download our eBook to learn how to select the right materials for your circuit boards.

PCB Material Design Guide

9 Chapters - 30 Pages - 40 Minute Read
What's Inside:
  • Basic properties of the dielectric material to be considered
  • Signal loss in PCB substrates
  • Copper foil selection
  • Key considerations for choosing PCB materials

Step 10: Outer layer imaging

This step utilizes photoresist, similar to the inner layers, but involves a positive image and follows the print-plate-etch method.

The key steps are:

  1. Panel cleaning: To ensure proper adhesion and imaging quality, the panels are thoroughly cleaned to eliminate any dust or contaminants.
  2. Photoresist application: A uniform layer of photoresist is applied over the cleaned panel surface, preparing it for imaging.
  3. Laser direct imaging (LDI): The circuit pattern is digitally printed onto the photoresist using LDI. This method ensures precise alignment and definition, as it directly corresponds to the CAD/CAM design.

Step 11: Copper plating

In this step, the holes and surface are electroplated with copper to ensure electrical connectivity between the layers of a printed circuit board.

Below are the key stages of the copper plating process:

  1. Pre-plate cleaning: Prior to plating, the panels are cleaned and activated in a sequence of chemical baths to ensure optimal surface condition.
  2. Electroplating setup: During electroplating, the panels function as cathodes in an electrolytic cell. Soluble anodes are typically used to supply current and copper replenishment to the bath. Since the holes already contain a thin, conductive layer of copper (deposited during the earlier electroless copper processes), they can now be electroplated. Copper is deposited onto both the surface and inside the hole walls.
  3. Controlled copper deposition: Rectifiers with precise power controls are used to ensure the copper is evenly deposited across both the hole wall on the surface of the panel.
  4. Tin plating: Following copper plating, a tin layer is electroplated onto the surface. It prevents corrosion of surface features such as copper pads, hole pads, and hole walls during the etching of the outer layer.

Step 12: Photoresist stripping

Once the panel is plated, the photo-resist will be stripped off to expose the unwanted copper.

A single continuous process line is used to dissolve and wash off the photoresist that covers the copper areas intended for removal. This step ensures that the panel is properly prepared for the subsequent etching phase.

Step 13: Final etching

In this stage, the unwanted exposed copper is chemically removed using an ammoniacal etchant. The areas of copper protected by a tin layer remain intact, as the tin acts as a resist against the etching solution. This process precisely defines the conducting paths and establishes the final circuit connections on the board.

For more, see wet PCB etching using acidic and alkaline methods.

Step 14: Tin stripping

Post etching, the protective tin layer present on the copper tracks is removed. This is achieved using concentrated nitric acid, which effectively dissolves the tin without damaging the copper underneath. As a result, a clean and well-defined outline of the copper tracks becomes visible on the PCB surface.

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Step 15: Solder mask application

Solder mask in PCB serves the following purposes:

  1. It provides insulation resistance to the traces.
  2. Distinguishes solderable and non-solderable areas.
  3. Provides protection against environmental conditions by covering non-solderable areas with ink.

The application process typically involves the LPI (liquid photo imageable) mask, which allows precise and uniform coverage across various board surfaces. Here’s an overview of the process:

  1. LPI coating: A liquid photo imageable mask composed of solvents and polymers is applied to the board surface, forming a thin, photo-sensitive layer that adheres to various board surfaces.
  2. Imaging: The coated panel is imaged using a printer system. A UV lamp in the machine exposes the transparent areas of the design, hardening the mask in those regions.
  3. Developing: The unhardened (unexposed) ink is chemically stripped from the board, leaving only the desired mask pattern.
  4. Curing (drying): The mask is cured to chemically bond the ink with the dielectric material, enhancing adhesion.
  5. Final baking: As a final step, the board is baked in an oven or under infrared heat to fully dry and harden the solder mask, completing the process.

This process ensures the resistive layer is accurately aligned and fully integrated with the circuit board structure.

Green became the standard solder mask color because it doesn’t strain the eyes. Before automated inspection systems were introduced, PCB inspection was done manually. The overhead lighting used by technicians did not reflect as harshly off the green mask, reducing glare and making it safer and more comfortable for extended visual inspections.

Step 16: Surface finish

PCB surface finishes form intermetallic joints between the bare copper on the solderable areas of a circuit board and its components. The base copper is highly susceptible to oxidation without a protective coating, so applying a surface finish is essential to prevent corrosion. Additionally, the surface finish prepares the board for soldering during assembly and helps extend its shelf life.

Lead-free PCB manufacturing demands surface finishes that can withstand higher processing temperatures and meet environmental compliance standards.

There are various types of surface finishes available. However, lead-free surface finishes are widely used in PCB fabrication process due to the strict RoHS (restriction of hazardous substances) norms.

Table 1: Classification of surface finishes

Type Surface finish Description Metallic HASL (hot air solder leveling) Solder coating by dipping in molten tin-lead solder and removing excess with hot air. Lead-free HASL Variation of HASL using RoHS-compliant lead-free solder alloys like Sn/Ag/Cu. ENIG (electroless nickel immersion gold) Thin gold over nickel layer to prevent copper oxidation. ENEPIG Combination of nickel, palladium, and gold for high solderability and oxidation resistance. Hard gold Thick, durable gold plating over nickel, used in high-wear areas like edge connectors. Soft gold Primarily used for wire bond pads or where a thicker gold deposit is required. Immersion silver (ImAg) Lead-free silver coating that protects copper through an immersion reaction. Immersion tin (ImSn) Thin tin layer on copper, suitable for fine-pitch and RoHS-compliant boards. Organic OSP (organic solderability preservative) Water-based organic coating to protect copper until soldering.

While choosing a surface finish, consider the factors such as cost, environment, component selection, shelf life, and production volume.

Step 17: Silkscreen

In this process, inkjet projectors are used to image the legends directly from the board’s digital data.

The ink is spread on the surface of the panel using a jet printer. The panels are then baked to cure the ink. It designates different kinds of text such as part number, name, code, logos, etc.

There are two types of silkscreen printing:

  1. Manual screen printing
  2. Direct legend printing

Step 18: Electrical test or E-test

E-test refers to bare board electrical testing. In this step, electrical probes are used to check for shorts, opens, and netlist integrity.

This test verifies the electrical conductivity of the circuit board using the netlist file, which contains information about the PCB’s intended interconnection patterns.

Flying probe testing

Flying probe tests in PCB are implemented to test for functionality. The test is done using probes that move from one point to another based on instructions provided by specialized software. It is a fixtureless test method.

Initially, flying probe test (FPT) programs are created and then loaded into the FPT tester. The tester applies electrical signals and power to the probe points and measures the results according to the test program.

Step 19: Routing and v-scoring

Circuit boards are profiled and cut out of the production panel during the final stage of the PCB manufacturing process. This is typically done using either a router or a V-scoring machine.

The V-groove method cuts diagonal channels on both sides of the board, while the router leaves small tabs along the borders. In either case, the boards can be easily popped out from the panel.

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Contact us to discuss your requirements of consumer electronics PCB manufacturer. Our experienced sales team can help you identify the options that best suit your needs.

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