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What is Printed Circuit Board Copper Clad Laminate?

What is Printed Circuit Board Copper Clad Laminate?

Printed circuit boards come in different materials known as substrate, including copper-clad laminate or CCL. PCB substrates are either organic or inorganic, depending on their properties. The organic substrates come up in different materials known as the reinforced board, such as glass felt, fiberglass, fiber paper, fiber cloth, and so on.
PCB fabricators impregnate there in forcing materials with an adhesive called resin, making it dry, and then cover it with copper foil at high pressure and temperature. Such a substrate is CCL or copper-clad laminate that resides on either one or both sides of the board. So, CCL is either single-sided or double-sided.
Rigid PCB has a rigid CCL with a substrate, such as

  • Resin epoxy FR4
  • PTFE
  • Aluminum or copper
  • Ceramic

These materials help make different types of PCBs, including single, double, and multilayer PCBs.

CCL Standards

Engineers define the CCL standard specification with ASTM D1867 and develop their circuit boards according to these standards. To cover twelve grades of CCL, ASTM needs the laminates to meet certain factors for peel strength, like

  • High temperatures
  • Volume resistivity
  • Water absorption
  • Flammability ratings
  • Dissipation
  • Dielectric breakdown
  • Permittivity
  • Lengthwise and crosswise strength

The PCB Manufacturer should also check the CCL for twist, warp, or blistering. CCL manufacturers often follow the IPC-410IC as a standard. Moreover, they use IPC-IM650 to test the fabricated CCL.

CCL Materials

FF4 CCL: As discussed above FR4 is a popular material for copper-clad laminate. The material is resin epoxy, and it is ideal for rigid circuit boards. You will see it on both sides and only one side of the board. The material is a combination of epoxy resin and fiberglass cloth. Resin makes the board fire resistant that’s why we abbreviate it as FR or flame retardant. However, it has to pass through testing to see if it is according to the UL94V-0 standards.

Copper base: like aluminum CCL, copper core CCL has a copper plate, copper foil, and dielectric layer for bonding. PCB’s thermal dissipation and dielectric bonding determine the overall thermal conductivity.
PCB with copper substrate has three types, depending on its design, such as copper without PTH, COB, or chip-on-board copper circuit board which is without the thermal pad insulation.
Aluminum CCL: Copper-clad laminate also has aluminum as a base material combined with a dielectric layer and copper foil. These materials are bonded through hot pressing and very high temperatures. The dielectric bonding determines the thermal conductivity of the aluminum core laminate. However, both copper foil and dielectric have high conductivity, and manufacturers often use ceramic to fill the dielectric layer.

What Is RF, Radio Frequency CCL?

The RF CCL is also known as the Microwave PC Board CCL as the board has microwave frequencies. Such a circuit board has certain characteristics to consider, such as

  • DK, dielectric constant
  • DF, dissipation factor
  • CTE, coefficient of thermal expansion
  • TCDR thermal coefficient of dielectric constant
  • Thermal conductivity

It involves high-frequency materials of which PTFE is a common practice. It is a synthetic material having great dielectric properties at high frequencies which are also known as microwave frequencies. A few companies develop the high-frequency PCB CCL, including Isola, Rogers, Taconic, and Panasonic.

What is Prepreg in CCL?

Prepreg or pre-impregnated CCL is a kind of fiberglass that is impregnated with a bonding material such as resin. The resin is not hard, however, it is dry and gets sticky when heated. In other words, the fiberglass is made strong through an adhesive just like FR4.
Prepreg materials come up in different thicknesses that determine their quality, such as standard resin, SR, medium resin, MR, or, high resin, HR. The PC Board manufacturer use the resin thickness according to the type of PCB they require.

What is Printed Circuit Board Copper Clad Laminate?
Printed Circuit Board Copper Clad Laminate

CCL PCB Applications

PCB with copper clad laminate is ideal for:

  • Electronics PCBs
  • Radars
  • High-speed communication devices, like 4G,5G, and LTE
  • Automotive products, such as ADAS radar
  • Avionics Radar
  • Automobiles
  • Welded tanks
  • Offshore platform shearing
  • Steam condenses
  • Pressure vessels
  • Heat exchangers
  • Missile components
  • Hydraulic bushings

The above applications related to communications are essential to communicate faster, such as 4G helps you download anything within seconds. Whereas 5G is much faster, in this case, and you can see it by comparing it with the old and low-speed communication devices.

How To Identify The Best CCL PCB

A few parameters help you find if the copper-clad PCB is the best or not, such as size, neatness or appearance, chemical properties, performance according to the environment, as well as a physical performance.

PCB Design Parameters Including Size: The size of the CCL matters a lot in PCB design as it’s the base material. The quality of the end product also depends on the thickness of the core material. At the same time, you have to consider other parameters, including length, width, wattage, and diagonal deviation. Each design parameter should meet the necessary standards to have an ideal product that performs well.

CCL Appearance: several issues happen during Printed Circuit Board manufacturing that can affect the appearance of the copper foil. Such as dents, pinholes, scratches, resin points, bubbles, wrinkles, etc. These issues also slow down the PCB CCL performance.

Environmental Compatible: Copper-clad laminate PCB should be compatible with the environment. Like, it should resist water and corrosion or its production will get slow, resulting in serious issues.

Chemical Function: The chemical properties of copper-clad laminate are also vital and should be according to the standards in terms of flammability. The Z-CTE or, Z-axis coefficient of thermal expansion, Tag, chemical resistance, and dimensional stability has to be considered.

Physical Function: Copper-clad laminate has to meet certain physical requirements, including the PS or peel strength, bending strength, dimensional balance, heat resistance, as well as punching. It should resist thermal stress.

Electric Property: Copper-clad laminate should electrically perform high, as it’s very important. As described above, copper-clad laminate PCB should strictly meet certain requirements, such as DF, DK, insulation resistance, CTI or comparative tracking index electric strength, arc resistance, and volume resistance.

How Many Types Of Copper Clad Laminate Are There?

You can classify the copper-clad laminate according to different factors, such as size, thickness, mechanical material, structure, insulation material, types of reinforcement, resin type, and CCL performance.
Copper-clad laminate is either rigid or flexible of which rigid CCL is further divided, depending on its combination materials. It is either single or double-sided, besides there are also special rigid CCL PCBs with a high-flame resistance and other properties.
Flexible CCL: It includes,

  • Non-flame retardant polyester
  • Flame retardant polyester
  • Polyimides with and without flame retardant
  • Fiberglass cloth of small thickness

Benefits of Flexible Copper Clad Laminate

  • The FCCL has many benefits, such as
  • It has great flexing power
  • It is ECO friendly
  • It is free from halogen
  • Better heat resistance
  • Great adhesive properties
  • it is a blend of different copper clad thickness

Special copper-clad laminate has ceramic and it’s also called ceramic CCL. It has different materials, such as aluminum oxide, aluminium it ride, silicon carbide, boron nitride, and beryllium oxide.


What is the manufacturing process of CCL?
Copper-clad laminate has complex manufacturing, including rolled copper foil that acts as a conductive material. PCB fabricators impregnate the reinforcing materials with an adhesive called resin, making it dry, and then cover it with copper foil at high pressure and temperature.

What Are The Uses Of CCL PCB?
Copper-clad laminate is fiberglass mixed with resin and glass and it is on either one or both sides of the glass fabric. Engineers use it to develop radios, mobile devices, televisions, computers, digital devices, and other multiple electronics.

What Is Copper Foil In CCL?
Copper foil in CCL is a cathodic electrolytic material that lies on the metal foil in a PCB. The material is easy to bond with the insulating layer to provide a protective covering. It is also easy to corrode to make a circuit protector.

What are CCL Standards?
Copper-clad laminate standard specifications are defined with ASTM D1867 and engineers develop their circuit boards according to these standards. To cover twelve grades of CCL, ASTM needs the laminates to meet certain factors for peel strength.
The fabricators should also check the CCL for twist, warp, or blistering. Copper-clad laminate manufacturers often follow the IPC-410IC as a standard. Moreover, they have to use IPC-IM650 to test the fabricated CCL.

Final Thoughts

PCB different materials known as substrate, including copper clad laminate or CCL. PCB substrates are either organic or inorganic, depending on their properties. The organic substrates come up in different materials known as reinforced boards, such as glass felt, fiberglass, fiber paper, fiber cloth, and so on.
PCB fabricators impregnate the reinforcing materials with an adhesive called resin, making it dry, and then cover it with copper foil at high pressure and temperature. Such a substrate is CCL or copper-clad laminate that resides on either one or both sides of the board.
Would like to know more about Copper Clad Laminate or prototype pcb manufacturer? Email us at sales@pnconline.com

Six Basic PCB Design Principles

Six Basic PCB Design Principles

Printed circuit boards are vital parts of smart devices and several equipments as they provide current or electrical signals to run them. You need different elements to construct a PCB, such as:

  • Schematic design
  • Database login
  • Electronic component configuration
  • Design preparation
  • Wiring
  • Block division
  • Testing

If any issue happens during a process, you have to go back to the previous process to correct it. The layout of PCB components is a complex thin as it determines a board\s appearance and neatness. Moreover, it also affects the function of the end product or device. We will discuss below the six basic PCB design principles in terms of its components and other factors.

1-Components Layout and Clearance

You have to place the components evenly on the board, leaving some space on the edges. The components around the edge should be 3mm away from PCB edges. In general, designers leave 5 to 10 mm space around the edges.

The components should be only on a board’s one side. There should be a separate pad for each lead pin.

Don’t cross up and down the components’ layout and keep a certain distance between the nearby components on the board. However, this distance should not be too small as it can hinder PCB maintenance.

Components should be installed at a low height and its lead should not be more than 5mm away from the PCB, as it can affect its quality to bear vibration.

Printed Circuit Board components that reside on a pad’s both ends must be a bit larger than their axial dimensions. The pads should be located where the coordinate grid intersects. The central distance of the pad has to be more than the board thickness to have a neat layout.

According to IEC or International Electrotechnical Commission, the standard spacing of the coordinate grid should be 2.54mm, whereas the axillary spacing should be 1.27mm.

However, these standards practically impact a few processes, including automatic drilling, computer automated design, components welding, and automatic assembly. But, such a grid spacing is not restricted in the case of manual drilling.

2-Defined Solder Mask

Solder mask expansion should be well-defined as it can cause issues if you over-define or under-define it. Tombstoning may happen if you don’t define the solder mask properly. Like, one side cools down faster than another side, affecting the board. So, by following the right parameters, you won’t have to revise your design.

The solder mask opening should be larger than the pad. In general, it expands 4 mils or 0.1mm. However, both can also have the same size, depending on the Printed Circuit board Fabrication.

3- Via Type& Routing Width

You must use the right via for routing as it won’t work if its diameter or ratio is not precise. The current won’t pass correctly due to fused vias. So, via styles should be considered while routing the entire PCB.

The routs should have enough width to carry the current that your device requires. You must have an impedance-controlled routing that needs various impedance profiles. You have to apply these profiles to routing widths to ensure a functional layout. Don’t have routing at an acute angle even if the signals have a low speed as acute angle hinders manufacturing. Like, an acute angle can increase the corrosion, leading to an open circuit.

Whereas it is vital to avoid the acute angle in the case of high-frequency circuits because it fully changes the track width at the corners and results in poor signals and discontinued impedance.

Six Basic PCB Design Principles
Six Basic PCB Design Principles

4-Components Installation

Different PC Board components are installed either vertically or horizontally. The horizontal components are parallel to the surface of the circuit board. Whereas in vertical installation, components are perpendicular to the PCB surface.

Vertical components allow you to have more quantity on a board’s surface. It is ideal for hearing aids, semiconductor radios, portable instruments, or devices that need a dense placement of components. For vertical installation, components have to be lightweight. Don’t install heavy components in a vertical direction as it can affect a PCB’s mechanical strength. Moreover, it causes vibration, and components can collapse, making a circuit less reliable.

On the other hand, the horizontal installation provides mechanical stability, and the circuit board also looks neat. It also helps lay down the printed wires because it enhances the elements’ span.

You can use any installation method, depending on your needs but make sure to arrange components evenly and the circuit should be anti-vibration.

5-Considering The PCB Layout Type

PCB layout has either a regular arrangement of components or is irregular. In an irregular format, the axis of the components are not aligned with each other, so it seems messy. However, it helps lay down the printed wires easily as there is no restriction of direction. Such a layout is ideal for high-frequency circuits and involves a vertical installation.

Whereas in a regular format, the component axis is aligned and either parallel or perpendicular to the sides of a PCB. It provides a neat board and makes certain processes easier, like PCB assembly, debugging, welding, maintenance, and production.

Moreover, a regular format is ideal for low-frequency circuits where the board has a few component types and its surface is loose. However, the number of components is high and such an arrangement also suits electronic instruments. But, due to the direction restrictions, such a PCB has a complex layout of wires, increasing the overall length of the wires.

6-Factors That Affect the PCB Layout

You also have to consider the factors that affect a PCB layout, like the direction of the signals, device position electromagnetic interference, thermal interference, mechanical strength, etc.

  • Generally, the direction of the signal flow is from left to right of which left is the input and right is the output. It is also from top to bottom of which the top is the input and the bottom is the output. Connectors which are in direct connection to the input and output should be close to the input and output connectors. Integrated circuits or transistors should be the core components. Whereas other components should be located according to their electrodes’ location. You should also consider the size, a number of pins, shape, and polarity of components.
  • You should adopt certain ways to prevent electromagnetic interference that occurs due to different external factors, like spatial electromagnetic ways, poor wiring, poor installation of components, etc. You can avoid these issues during the layout design. But, interference will happen if the PCB design is not right
  • You should shield the components that interfere with each other. High-frequency components should have small wiring. Similarly, the components of weak and strong currents should be separated. Wires with high potential should be at a great distance to avoid 50Hz interference. Likewise, the metal components should not be adjacent or they should be well-insulated to avoid a short circuit.
  • While designing a PCB, you must know which components are temperature sensitive and which are heat components. The heating components like resistors should be located near the shell or near vent holes to dissipate heat. Don’t place many heating components near each other. Also, use fans or radiators to prevent the rise in temperature beyond its limit.
  • Whereas the temperature-sensitive components should be away from the heat source. In general, integrated circuits, transistors, electrolytic capacitors, and thermal components are temperature sensitive. These components get affected due to the rise in temperature, especially in a circuit’s long-term operation.
  • The board should also be mechanically strong and its center of gravity should be stable. Don’t install heavy or heating components directly on the board, instead, they should be under the chassis to have a stable board. If the board size is above 200mm it will cause mechanical stress, so it should be strengthened with a mechanical frame.

Finally, many PCB design software uses the power layer to have a fast design process. You can connect more wires to ensure the current has a minimum impedance or voltage drop down, thus giving enough ground return paths.


1.How To Layout A Printed Circuit Board?
You have to follow certain steps to create a PCB layout. Such as making the schematic drawings, developing a blank PCB layout, creating a PCB stack-up, schematic capture, defining design principles, defining DFM, linking to PCB, placement of components, inserting drill holes, and the route traces.

2.Is It Hard To Design A PCB?
It is not hard to design your PCB if the electrical schematic is right. Besides, following the design parameters also makes the design process easy.

3.Why Is My PCB Green?
The color of the solder mask determines the PCB color. So, if the solder mask is green, you say that PCB is green. The solder mask shields a copper circuit to avoid shorts circuit or soldering issues.

4.What Is The Purpose Of Following PCB Design Rules?
PCB design rules or principles help you to develop a system to automate the testing of design requirements. You get an interface between the physical and logical sides to create a circuit board. So, you can automate the DFM tests by following the rules to ensure that you can build a PCB.
Would like to know more about Design Principles or PC Board assembly? Write us at sales@pnconline.com

PCB Design Guidelines For Reduced Electromagnetic Interference

PCB Design Guidelines For Reduced Electromagnetic Interference

Printed circuits should be well designed and well-built to help devices work accurately. These circuits should have good materials to minimize certain issues, including the high EMI or electromagnetic interface. On the other hand, poor design can cause weak signals and high radiation, disabling the device. Here, we will discuss all essentials of EMI and how to reduce it.
Electromagnetic interference or EMI is defined as any disturbance that affects an electrical circuit due to either electromagnetic induction or electromagnetic radiation. The effects of EMI can range from a simple degradation of signal quality to complete equipment failure. In order to avoid these negative effects, it is important to design your Printed Circuit Board with EMI in mind.
Reduced electromagnetic interference (EMI) on your circuit board ensures that your electronic devices and products don’t interfere with nearby electronics and may even improve the overall performance of your products. We will share some key tips that you can follow to help reduce the EMI generated by your circuit boards and improve the performance of your final products.

PCB Design Guidelines For Reduced Electromagnetic Interference
PCB Design Guidelines For Reduced Electromagnetic Interference

Optimizing the EMI PCB Design

Electromagnetic interference has many reasons,and you have to reduce it through the filter.You can create the EMI filters using a single component or a network of many components having dedicated circuits to reduce different mode noises. Now, we will discuss the EMI filter design and its standard types.
After deciding on the basic EMI design, you will have to optimize it through a circuit board’s specifications. Like, if the purpose of the EMI filter design is to drive other PCBs, you must add more filter elements to have smoothing, isolation, and limits of electrical parameters. The limitof meeting the board’s needs depends on the PCB design capabilities and the available analysis methods.

How PCB EMI Happens

You will see electromagnetic frequencies everywhere all around you, such as appliances, or electronic products having current. EMI falls into different categories when it comes to PCB.

  • High-power devices cause EMI, like amplifiers, antennas, processors, FPGAs transmitters, etc.
  • Moreover, the change of components can also cause interference affecting g the device.
  • EMI often occurs along traces and at connector points. Unnecessary coupling occurs between the ground planes and signal paths because of lost capacitance.
  • EMI also happens due to external sources, like when the board is near a source that emits radiation. This external source can be a device, equipment, or some other circuit board.

It is very hard to eliminate all types of EMI sources, but following certaindesign rules can help in this case. You can minimize the disturbing noises through different techniques that we will describe in this article.
What Are EMI Design Guidelines?
Like every PCBoard, there are certain design parameters to follow while designing a suitable EMI filter design. You have to adopt a certain perspective in this case, as described below.
PCB Design Perspective 2-Dimensional
First of all, you have to make marks for component placementwhich you can do through a design software library, or you can upload a file taking it from other sources. It also involves spacing, routing of traces, and design clearances. But, you will have to consider a few things to do so, such as:

  1. Make sure that component libraries and pads are compatible.
  2. There should be a maximum distance between the adjacent elements, such as traces, pads, and annular rings, as it will reduce the EMI.
  3. Designers should consider the types ofsignals for component partitioning.
  4. Make sure that the trace size or width is according to the required current capacities.
  5. The impedance compatibility should be addressed in terms ofexcellent power transfer and differential routing.
  6. Make sure to provide thedepenalization according to the terms and conditions of the board clearance.
  7. Devices with high radiation should be shielded.
  8. Silkscreen should be used wisely to enhance PCB assembly through reference points and component polarities.

Various Techniques To Minimize EMI

Design should involve minimum EMI, and you can achieve it by adopting different techniques.

Reducing The EMI Through A Ground Plane

The first barrier against EMI is the ground plane, as PCB needs a floating surface to function effectively. Printed circuit boards have a ground plane to give a reference line of 0 volts and take it to the power supply terminal for a circuit’s return path.

The circuit board becomes an antenna when there is noise due to ripples. A circuit board’s copper foil or the ground planeoccupies the maximum cross-sectional area of the circuit board. So, you can reduce the EMI or electromagnetic interference by effectively using the ground plane.

Reducing EMI Through Trace Layout

The conductive paths on the circuit boards are known as traces. Flowing electrons occur in traces due to an active circuit and are a little away from developing a radiating antenna.There are certain guidelines to follow regarding trace layouts, such as:

  • There should not be bends with sharp angles. Instead,round right angles are suitable to reduce reflections that occur due to an increase in capacitance in the corner areas lying at 45 degrees.
  • High-speed traces should be away from the low-strength signals. You can take an example of a clock that has high-speed signals. Whereas analog and digital signals should also be separate from each other.
  • The return paths should not be long, instead, make them short.
  • The differential traces should be close enough to enhance coupling. This techniquebrings influenced noises into a less problematic mode.
  • There should be a wise usage of vias as they help you take benefit of a circuit board’s multiple layers while routing.Designers should know that thereflections happen due to a change in impedance.
  • Different traces should not have vias. However, in case you need so, then you can have an oval anti-pad which two vias share, reducing the parasitic capacitance.

SomeWays of Reducing EMI from Components

  • Try to choose low-power consumption components.
  • You can use USB circuits within an enclosure, like PCB guards or Faraday cages. They can also eliminate the EMI from the circuitboard’s surroundings.
  • Use heat dissipation methods to avoid the EMI. Proper heat sinks and vias help in this case.
  • All the above techniques and guidelines can help you reduce EMI. But, the design, function, and PCB performance goals determine the EMI reduction technique you should choose.

Some Other Ways

Place decoupling capacitors close to the power pins of your ICs. These provide more capacitance closer to the source, reducing both conducted and radiated EMI.
Make sure you are soldering all components with enough solder so that there is no exposed metal at any point on the circuit board.
If possible, position sensitive analog circuits such as amplifiers or comparators away from digital circuits such as processors or microcontrollers.
Shielding (copper foil) can be used in conjunction with shielding paint to improve RF performance further. Shielding paint is usually made of copper powder mixed into an acrylic binder. The copper reacts chemically with air, so shielding paint should not be used in damp environments where there may be high humidity or condensation levels. In most cases, paints will have a shelf life of up to five years if stored in a dry place without exposure to sunlight.

EMI Optimized Circuit Board through PSpice

There is a simulation tool known as PSpice which can help you to analyze the electrical parameters of a PCB design. However, it should be done before submitting your design for construction.
Ithelps evaluate heat dissipation and distribution methods, different simulations, anda circuit’s behavior in different conditions.
You can use the PSpice Advanced Analysis tool for this purpose. You can optimize a PCB for minimizing EMI by following the design guidelines and using advanced methods.


What is EMI in PCB?
Electromagnetic interference or EMI is defined as any disturbance that affects an electrical circuit due to either electromagnetic induction or electromagnetic radiation.
How To Reduce EMI?
You can reduce PCB EMI through traces, a ground plane, PSpice, and some other methods.
What Are the Reasons For EMI?
High-power devices cause EMI, like amplifiers, antennas, processors, FPGAs transmitters, etc. The change of components can also cause interference affecting the device.

Wrap Up

Electromagnetic interference (EMI) from power lines and high-voltage devices can damage circuitry, which can lead to failures in equipment and even safety issues. This article focuses on PCB design guidelines that will help you prevent EMI on your PCBs by making them less susceptible to outside interference, particularly during the power-up sequence.
By applying the guidelines described in this article, your designs will have lower susceptibility to radiated emissions, conducted emissions, and common-mode currents, making them less vulnerable to damage from outside sources of EMI.
Would like to know more about design guidelines for reduced EMI or printed circuit board assembly? Email us at sales@pnconline.com