Blog

Uncover the latest PCB innovations, expert insights, and industry trends with PCBX's comprehensive blog. Stay ahead of the curve in PCB design, manufacturing, and assembly.

Printed circuit board Blog - PCBX

PCB Design

The PCB Design Resource Channel is a worthwhile location that provides electronic engineers and designers with top-notch resources and tools to design printed circuit boards. In this section, the latest guides in design, tutorial videos, software tools, example projects, and best practices are organized together for reference on how best to go about optimizing the design process for better work efficiency and product quality.

PCB Design - PCB Expert Manufacturing - PCBX

PCB Resources

Your comprehensive PCB knowledge resource. Explore in-depth guides on PCB design, material selection, fabrication techniques, and industry trends. Empower your PCB expertise today! 

PCB Resources - PCB Expert Manufacturing - PCBX

PCBA Resources

PCBX: Master the art of PCB assembly. Delve into expert guides on PCB assembly processes, techniques, and quality control procedures. Elevate your PCB assembly skills now! 

PCBA Resources - PCB Expert Manufacturing - PCBX

Creepage and Clearance in High-Voltage PCB Design

Creepage distance and clearance distance are two basic design parameters that are critical in high‑voltage printed circuit board (PCB) systems for ensuring electrical safety, insulation reliability and long service life. The two quantifiers are the minimum spatial distance between conductive parts that are at different voltage potentials from each other such that air breakdown, surface tracking, arcing, flashover and insulation failure are prevented. Proper creepage and clearance design is essential for meeting global safety standards as well as for reliable operation in harsh environments in industrial power supplies, automotive power modules, renewable energy converters and high-voltage measurement devices. This article will methodically cover the definitions, influencing factors, industry requirements, practical design guidelines, common challenges and engineering solutions for creepage and clearance, so that designers can produce safe, reliable and manufacturable high-voltage PCB designs.<h3>Core Concepts: Clearance and Creepage</h3>Clearance is the shortest straight line distance through air between two conductive parts. Avoids air breakdown and arcing due to high electric field strength. Clearance is affected by voltage, humidity and altitude. Typical clearances for a 1000V DC circuit under normal atmospheric conditions are approximately 8 mm.The shortest path on the surface of the PCB substrate between conductive elements is called creepage. It is immune to surface tracking due to dust, moisture, flux residue, or corrosion. Under high voltage, contaminants can develop into weak conductive layers that can produce permanent carbonized contacts. Typically, creepage is greater than clearance. In case of a 500 V system, creepage may be required to be 6.4 mm or more, depending on the material and environment.<img src="https://img.pcbx.com/dev/file/image/article/20260602/1518e55c5dac453ba1af04b198703f2a.jpg" alt="Clearance and Creepage-PCBX" data-href="" style="width: 100%;"/><h3>Key Factors Determining Creepage and Clearance Requirements</h3>The minimum creepage and clearance values are not fixed values. The factors that determine them are voltage stress, environment, material characteristics, and application safety levels.Operating Voltage and Overvoltage CategoryLarger insulation spacing is necessary for higher working voltage, peak voltage and impulse surge. The design margin should account for transient overvoltages due to lightning, switching or load changes.Pollution DegreeThe world recognizes four pollution levels:There are international standards for environments which are divided into four pollution degrees: In clean indoor enviroments (Pollution Degree 1), the creepage distances are much shorter than in industrial or humid enviroments (Pollution Degree 2 – 3), where they are much longer to limit tracking due to contamination.Substrate Material and CTIThe Comparative Tracking Index (CTI) is an indication of a material's ability to resist surface tracking. Materials are classified according to their CTI values into Groups I–IIIb. Higher-CTI materials can be used with smaller creepage distances at a given voltage stress. The commonly used FR‑4 for general high voltage use has a CTI of 400 or higher.Altitude CorrectionThe density of air and the strength of the dielectrics both decrease with altitude. Above 3000 m, the clearance of the equipment typically has to be increased to provide the same insulation levels.Insulation TypeThe minimum spacing corresponds to basic insulation, supplementary insulation, double insulation and reinforced insulation. The largest creepage and clearance is needed for reinforced insulation in safety critical applications.<h3>Industry Standards: IPC‑2221 and IEC Series</h3>Designs are mature and are in line with internationally agreed standards for consistent safety performance.IPC‑2221 is the universal PCB design code that offers straightforward tables for creepage and clearance according to voltage, coating and environment. It generally gives 10mm creepage and 8 mm clearance for 1000 V and Pollution Degree 2 and Group II material.Insulation coordination for low and medium voltage systems is covered by IEC 60664‑1. IEC 62368-1 is adopted by many for the safety certification of audio-visual, IT and communication equipment. The most severe standards that apply should be used by designers for market compliance.<h3>Practical Design Rules for High‑Voltage PCBs</h3>To balance safety, layout density and manufacturability, the following rules are based on standard requirements and engineering experience.Define voltage stress and environment firstCheck maximum operating voltage, transient surge and worst case pollution and altitude. All spacing calculations are to be based on these conditions.Choose high-CTI substrate materialsChoose substrates that have good tracking resistance to minimize creepage needs and enhance reliability.Use slots and barriers to extend creepageIn situations where there is limited board space, spaces between the high-voltage traces can provide a long path of surface routing with minimal board area. The effective creepage distance can be increased by several millimeters by adding a narrow slot.Optimize component placement and partitioningPhysically separate high voltage and low voltage areas. Avoid sharp corners and narrow gaps that cause electric‑field concentration. Ensure adequate separation between high voltage pins and copper.Apply conformal coating properlyCoating can be used to achieve better surface insulation and/or reduced creepage in some circumstances. But it can not be used to replace the minimum spacing required by standards, and the process defects must be avoided.Verify with automatic design tools and testingMake use of PCB design software that allows for the enforcement of creepage / clearance rules during design layout. Following the fabrications perform hipot (high potential) and dielectric withstand testing to confirm insulation performance.<img src="https://img.pcbx.com/dev/file/image/article/20260602/ceb5c2fc7a114b3b808450f6a4b1e2dc.jpg" alt="Design Rules for High‑Voltage PCBs-PCBX" data-href="" style="width: 100%;"/>The two fundamental aspects of safely and robustly designing high voltage PCBs are creepage and clearance. They bridge electrical theory, material science, environmental adaptability, and industrial certification. If applied correctly, these parameters help prevent arcing, tracking, short circuit and fire hazards, and ensure products adhere to global safety standards and perform their required functions throughout their life span.PCBX offers high voltage PCB design consultation and manufacturing services to meet strict creepage and clearance control requirements, high CTI materials, precision slotting and conformal coating requirements. PCBX facilitates customers in the process of how to convert their well designed high-voltage products into mass production products with high quality and safety performance, and has rich experience in IPC‑2221 and IEC insulation standards.

Explore critical creepage & clearance specifications for high voltage PCB design, including global standards and proven layout best practices.

Top 10 Wireless Router Manufacturers in the World

In the digital age, a dependable wireless router will be considered the cornerstone in any home or office, connectedly speaking. Driven by increasing demand to have fast and stable connectivity to the internet, the market also expands massively for wireless routers. Within this paper, we introduce the top 10 most prominent manufacturers of wireless routers that are considered leading companies when it comes to cutting-edge technology and innovation.<h3>Cisco</h3>Cisco is a well-known company in network technologies. With a reputation for high-power routers, Cisco targets enterprise and business customers more often than not. The high performance, strong security capabilities, and rich management capabilities of their routers are factors that make them widely employed in corporate networks.<img src="https://img.pcbx.com/dev/file/image/article/20241227/edaa5dfaa5de44379aee2ced5ade4a45.jpg" alt="Top 10 Wireless Router Manufacturers in the World-PCBX" data-href="" style="width: 100%;"/><h3>Netgear</h3>Netgear is a household name when it comes to consumer networking equipment. With a wide array of routers intended for use in both home and SOHO environments, they are known for having pretty friendly user interfaces and being generally reliable. Most of the models have parental controls, guest networks, and very easy setup. <h3>TP-Link</h3>TP-Link will no doubt hold the leading position on global market shares, especially considering that these features arrive in a pretty cost-efficient manner. These range from the most basic models in their product portfolio to a high-end router with newly developed technologies like Wi-Fi 6, Mesh networking, and even advanced security protocols.<h3>Asus</h3>Apart from being a computer hardware leader, Asus is also a well-known brand in the field of networking. Its routers are highly popular among gamers due to features such as low latency, high throughput, and gaming-specific optimizations. Further, innovative and sleek designs make them more attractive, together with powerful performance. <h3>D-Link</h3>With a strong foothold in the network equipment market, D-Link places strong emphasis on solution provision for both home users and business. Its routers are cost-effective, with a mix of basic to advanced features intended to meet varied connectivity requirements across different regions.<h3>Linksys</h3>Linksys, which Belkin acquired in 2013, is still one of the more popular brands offering reliable and easy-to-operate routers. It's been among the first to release technologies such as mesh networking and tri-band support, greatly improving both performance and range, particularly in larger homes.<h3>Huawei</h3>Huawei has rapidly expanded its influence in the telecom equipment sector, covering wireless routers. They enjoy a good reputation for original designs and the implementation of the latest technologies, largely for smart home implementations and connections to IoT devices.<h3>Xiaomi</h3>The company is a well-known manufacturer of network devices and has recently decided to extend its product portfolio beyond just smartphones. Generally, Xiaomi offers high-spec routers at very decent prices, sometimes with smart home ecosystem support and features that reflect the latest technological trends.<h3>Zyxel</h3>Zyxel is among industry leaders, specializing in broadband solutions and networking hardware. Primarily, Zyxel routers have always stood for powerful and stable performance, which, from time to time, placed them in the business sphere by offering functionality that meets broadband enhancement and enterprise network management.<h3>Ubiquiti Networks</h3>Ubiquiti Networks have managed to niche a market with professional-level networking equipment. Their routers are most liked by users at the advanced level and pros who want deep control of network settings, performance monitoring, and secure deployment options.<h3>Comparison of Top Wireless Router Manufacturers</h3>A lot comes into play when choosing a wireless router: performance, features, price, and intended use. Herein, we will compare these top manufacturers based on the key aspects to help you in making a well-informed decision.<h4>Performance and Speed</h4>Cisco: Basically meant for enterprise-level demands with exceptional speed, stability, and higher-end routing features; suitable for corporate usage.Netgear: Has been noted to offer very good speed and commendable performance, especially in its consumer-grade models.Asus: High-speed routers, especially for gamers, have settings like QoS, which is customizable. TP-Link: It gives a decent balance between performance and price. The high-end versions can be very competitive in terms of speed. <h4>Features and Technology </h4>Linksys: Pushes the envelope by providing mesh networking and tri-band support to extend coverage while minimizing dead spots. Huawei: Specializes in smart home and IoT integration, offering seamless connectivity between devices.Xiaomi: Supports smart homes and is often easily integrated with other Xiaomi products using app-based controls. Ubiquiti Networks: Well-known for professional-grade features, which appeal to more advanced users who want heavy control. <h4>Price Range </h4>TP-Link, Xiaomi: Strong on the price front, offering feature-rich routers at competitive prices, thus suiting budget-conscious buyers very well. Netgear, D-Link: Offer a wide range of products to suit every price bracket, hence they are good for both budget-oriented and performance-oriented users.Cisco and Ubiquiti Networks: These are on the higher price spectrum and are targeted at enterprise and professional users who need robust and scalable solutions.<h4>Target Audience</h4>Cisco and Ubiquiti Networks: Businesses and advanced users who require complex networking solutions.Netgear and Asus: Gamers and tech-savvy home users because of high performance and gaming-focused features.TP-Link, Xiaomi, and D-Link: Suitable for simple users and small businesses where spending less is the concern while not compromising on necessary features.Linksys and Huawei: A middle ground of consumer and smart home power users, providing features for enhanced connectivity and integration in the modern smart home setting.<img src="https://img.pcbx.com/dev/file/image/article/20241227/8d52fc0b6fc34035951261fcfbd69c45.jpg" alt="Top 10 Wireless Router Manufacturers in the World-PCBX" data-href="" style="width: 100%;"/>The choice of a wireless router maker should be in line with your needs and budget. Enterprises that need comprehensive and robust networks might lean towards Cisco or Ubiquiti Networks, while home users and gamers might prefer options from Asus or Netgear for their performance features. Those looking for more affordability without sacrificing key functionalities might find TP-Link and Xiaomi quite attractive.Each brand is best in different fields, so consider what aspect-performance, features, price, or compatibility-is most critical for your situation. These differences will help in picking the right router to suit your connectivity needs.

The article highlights the top 10 wireless router manufacturers, including Cisco, Netgear, and TP-Link, emphasizing their performance, features, and target markets.

In the electronic world, the Printed Circuit Board (PCB) plays a vital role in component mounting and interconnection, and central to many applications in technologically advanced fields. Various materials are utilized for producing Printed Circuit Boards, out of which FR4 material is predominant because it has shown a very good balance between the mechanical strength of the substrate and electrical insulation. One of the main factors of FR4 affecting PCB performance is its permittivity or dielectric constant, which has a great influence on how electrical signals are controlled and propagated inside the board. This article explores the subtlety of FR4 permittivity and its vital role in the design and functionality of PCBs.<h3>What is Permittivity?</h3>Permittivity is the extent of a dielectric material on the electric field and vice-versa. In the case of PCBs, it affects two main aspects: Speed of Signal Propagation: It is the speed with which the electrical signals can travel through the material. As a general rule, signal propagation is faster in lower-permittivity materials.Charge Storage Capacity: Storage capacity is the ability of the material to store electric charge at a specific point-a basic determining factor that influences capacitance and the whole electrical performance of PCB traces and layers.<img src="https://img.pcbx.com/dev/file/image/article/20241216/22b0bfc83e78479a87cabe6ef87b1d95.jpg" alt="FR4 Permittivity in PCB Design-PCBX" data-href="" style="width: 100%;"/><h3>Understanding FR4 and Its Dielectric Constant</h3>FR4 is a composite material of woven fiberglass and flame-resistant epoxy resin. Due to its strength and adaptability, FR4 is considered very important in the electronic world. The dielectric constant of FR4 is generally in the range of 3.8 to 4.8 but normally averages out at 4.3. This can actually be affected by many factors that include substrate thickness, resin content, copper foil roughness, and style of glass weave.Challenges with FR4 PermittivityVariability in Dielectric Constant: FR4 permittivity may be varied by changes in substrate properties and environmental conditions, such as temperature fluctuations and humidity, which can affect signal integrity and impede impedance control.FR4 Limitations at High Frequency: FR4 has dielectric properties at high frequency that may result in higher losses of signal and higher dissipation factors; hence, it is less effective in applications like RF circuits compared to specialized materials offering lower loss tangents.<h3>FR4 Permittivity in the Design of PCBs</h3>Permittivity plays a very important role in the design of a PCB, mainly influencing signal transmission and impedance control, which are crucial in high-speed digital and RF applications.Signal Integrity and Impedance ControlThe dielectric constant directly influences the levels of impedance and the speed of signal propagation. It is very important that the permittivity of FR4 be taken into consideration when determining trace widths and spacings to achieve consistent impedance and timing for preserving signal integrity.Issues with High-Speed and High-Frequency ApplicationsVariations in permittivity may result in performance inconsistencies of circuits operating at high frequencies. Non-uniform permittivity complicates impedance matching, potentially leading to signal reflection, distortion, and loss.Thermal and Mechanical PerformanceWhile FR4 is valued for its mechanical strength, excessive heat and high voltage can degrade its dielectric properties, affecting the board's long-term reliability and performance stability, especially in demanding applications.<h3>Overcoming FR4 Permittivity Challenges</h3>Despite its shortcomings, FR4 remains a widely used material because of its cost and general versatility. However, several approaches can be utilized to overcome problems with its permittivity:Use Advanced Design Tools: The use of sophisticated PCB design software, which includes stack-up utility designs and incorporates permittivity data, will enable designers to calculate impedance and propagation delays more accurately for a better overall board performance.Material Selection: Wherever the dielectric limitations of FR4 are an issue, choose alternative materials such as high-performance laminates that will offer stability and lower dielectric constants across a wider range of frequencies.Rigorous Testing Implementation: Stricter testing of the dielectric properties of FR4 in different conditions, especially considering the temperature-sensitive environments for reliable performance.<img src="https://img.pcbx.com/dev/file/image/article/20241216/7cb18d605e064607a9ad8cce65e2412d.jpg" alt="FR4 Permittivity in PCB Design-PCBX" data-href="" style="width: 100%;"/>FR4 permittivity forms one of the basic considerations of PCB design that influence the electrical behavior of signal propagation and overall circuit reliability. Though FR4 is highly efficient in general applications, in high-speed and high-frequency areas, managing its dielectric constraints plays an important role. By understanding these challenges and addressing them, engineers can take full advantage of FR4, hence optimally adapting PCBs to suit application needs. With the advances taking place in PCB technology, the ability to use FR4 with great efficiency is further enhanced through ongoing innovations in materials and design techniques that continue to emerge, securing FR4's position as a mainstay of modern electronics manufacturing.

FR4 permittivity affects PCB signal speed and impedance. It's crucial for design, requiring careful management in high-frequency applications for reliability.

FR4 Permittivity in PCB Design

In the field of power electronics, efficient and reliable PCB design is important. These boards are responsible for delivering and controlling high currents to drive components such as motors, heaters, or batteries. Meeting unique demands involves specialized layout techniques to ensure robustness, safety, and performance. This guide delves into essential principles and practices in power PCB design, focusing on managing high currents, minimizing inductance, thermal design, safety, EMI control, and component selection.<h3>Key Design Considerations</h3>Successful power PCB design involves addressing several key areas to ensure effectiveness and reliability:High Current Capacity: Use appropriate trace widths, multiple layers, and vias to handle high currents without overheating.Low Inductance: Shorten loops and interleave supply/return paths to avoid voltage spikes.Noise Isolation: Partition noise-sensitive sections and employ filtering to control interference.Thermal Management: Implement thermal reliefs and heatsinks to maintain safe temperatures.Safety: Design with proper insulation, spacing, and isolation to prevent hazards.EMI Control: Shielding, filtering, and good signal routing help control noise emissions and immunity.Reliability: Select components that can support continuous power cycling in addition to transient stresses.<img src="https://img.pcbx.com/dev/file/image/article/20241202/5e2f941a8bef4297bb434bf574dbba04.jpg" alt="Power PCB Design-PCBX" data-href="" style="width: 100%;"/><h4>Dealing with High Currents</h4>Power electronics can supply hundreds or thousands of amps. Hefty traces are required to carry these currents safely. Here's how:Thick Traces: Choose the trace widths according to current estimates. For example, 10A may be sufficient with at least 0.5mm (20mil) traces while 50A may require 1mm (40mil) or thicker traces. Consult ampacity tables for an accurate determination.Distribute Across Layers: Make use of multiple board layers with dedicated power distribution planes as such will allow dividing the current and avoiding trace overload. Use plated through-hole vias for effective conduction between layers.Incorporate Thermal Relief: Add thermal relief cutouts around traces that connect to inner layers. This will increase the exposed copper surfaces, aiding in localized heat dissipation and enhancing thermal management.<h4>Reducing Parasitic Inductance</h4>Parasitic inductance must be minimized when it comes to dynamic power circuits to avoid damaging voltage spikes:Short and Direct Paths: Keep the traces short and avoid right angles; if necessary, use 45° angles and prefer curved traces.Pair and Interleave: Route supply and return traces side-by-side, interleaving pairs to minimize loop area.Use Copper Fills: Utilize copper fills stitched to the ground plane via closely spaced vias to reduce inductance by disrupting magnetic flux lines.Eliminate Loops: Avoid loop structures in high di/dt paths; directly connect traces to reduce loop area.<h3>Partitioning for Noise Isolation</h3>Combating noise in power electronics that involve mixed analog and digital circuits requires strategic partitioning:Use dedicated grounds and power planes to isolate the analog sections from noisy digital areas.Split planes using isolation gaps and ferrite beads.Encircle sensitive circuits with guard traces to shield against noise.Supply input and I/O line filtering to avoid unwanted coupling.<h3>Thermal Design</h3>Many power components operate at high temperatures, requiring active thermal management:Thermal Pads and Polygons: Utilize broad thermal pads to spread heat from hot components.Thermal Spokes and Vias: These routes heat efficiently to inner layers.Direct Connection to Copper: Connect hot components directly to heavy copper areas, a chassis, or heatsinks for dissipation.Optimal Airflow: Ensure that good ventilation exists around temperature-sensitive components.Temperature-Resistant Material: The selection of materials should be those capable of withstanding elevated temperatures.<h3>Safety</h3>A designed power system should address the following safety concerns :Spacing and Insulation: There should be adequate spacing and insulation between high-voltage nodes.Protection Devices: Include fuses, current limiting resistors, and safe discharge paths.Compliance Standards: Follow safety standards for enclosure, spacing, insulation, etc.<h3>EMI Control</h3>Switching power electronics generate intensive noise usually, and hence, EMI containment is of much importance for compliance to standards:Shielding and Grounding: Shielding cans and effective use of grounded copper are necessary to contain emissions.Filtering Techniques: Feed-through capacitors and ferrite beads would be used for leakage filtering.Good Layout Practices: Good grounding, decoupling, and bypassing practices.Current Loop Management: Keep the loops compact and tracks short to minimize EMI.<h3>Component Selection</h3>The selection of proper components is a vital factor in achieving reliability:<h4>Passives</h4>Select high-wattage resistors, high-current inductors, capacitors with high ripple current ratings, and fuses for transient protection.Common-mode chokes may be used for EMI filtering.<h4>Actives</h4>MOSFETs, IGBTs, and Controllers appropriate for the loadChoose reliable vendors and apply conservative derating<h3>Example Power PCB Implementations</h3>A few examples of good power PCB designs include:Switch Mode Power Supply: interleaved paths, shielding, thermal relief, and safety spacing all in one. Power Amplifier: using copper fills, chassis mounting, separating analog/digital sections, and input/output filtering. Battery Charger: low-inductance traces, dedicated power distribution layers, liberal use of thermal relief.<img src="https://img.pcbx.com/dev/file/image/article/20241202/0690e0de317e473d868ea2a96d14dbf6.jpg" alt="Power PCB Design-PCBX" data-href="" style="width: 100%;"/>The design of robust power PCBs calls for a holistic approach to current management, inductance minimization, and safe, efficient operation. Application of these best practices and guidelines will enable the engineer to construct a reliable PCB that delivers consistent power under challenging conditions. Power integrity principles are mastered and deployed to deliver dependable, high-performance power solutions that can enable everything from consumer devices to industrial systems.

Effective power PCB design ensures high current handling, noise control, thermal management, and safety through specialized layout techniques and component selection.

PCBX.com Resources

Your source for industry knowledge, news, and expert insights

Latest Posts

Article