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PCB Design Guidelines For Reduced Electromagnetic Interference

PCB Design Guidelines For Reduced Electromagnetic Interference

PC Board, PCB Design, Printed Circuit Board, printed circuit board assembly, , ,

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.

FAQs

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

Printed Circuit Board FR4 Material

Printed Circuit Board FR4 Material

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FR4 is a blend of fiberglass and epoxy resin, and manufacturers also call it a composite material. It resists flame and is highly used for PCBs as a substrate or base layer. FR4 circuit boards are now used instead of G10 boards due to their properties.

FR is also a great electrical insulator because it is completely water-resistant which means it does not absorb a little drop of water. Such qualities mechanically make it very strong and it maintains its qualities in all kinds of weather, including humid, hot, and dry weather.

Properties of FR4

FR4 is an inflammable material, and it is UL94V-0 compliant which means it does not spread fire, instead, it stops fire the moment the material starts burning. It has bromine that resists fire and does not absorb water as described above.
Moreover,the glass transition temperature is very high ranging from 115 to 2000 degrees Celsius, depending on the type of the resin and manufacturing method.Mostly such PCBs FR4 lies between the two layers of copper laminates.

Types of FR4 Material

FR4 material has different types, such as:
Standard FR4: Its heat resistance goes up to 140-a50 degrees Celsius.
High CTI FR4: The index of this type of FR4 goes beyond 600V.
High TG FR4: It has a high-glass transition value, such as 180 degrees Celsius.
FR4 without copper: This type of FR4 is suitable for insulating plates, and it can support the circuit board.

How To Choose The FR4 Thickness

FR4 thickness should be decided carefully as it contributes a lot to the applications of different PCBs. You should consider the following things in this case:

  • Design and flexibility
  • FR4 thickness should be compatible with components
  • It should not take much space on a PCB
  • Focus on the type of desired connections

Advantages of FR4

FR4 is cheaper than other substrates of circuit boards which makes it a standard material to develop small circuit boards. But, it is not good for high-frequency circuits or where the parts are suitable for flexible circuit boards.
FR4 is often suitable for RF applications with a frequency from 1GHz to 10 GHz. However, electric products having an FR4 have some disadvantages due to certain limitations.
FR4 material is one of the most popular choices for printed circuit boards because it offers a high degree of strength and rigidity. This means that your PCBoard will be less likely to warp or bend over time, which can lead to reliability issues. As already mentioned, FR4 material has excellent thermal stability, meaning it can withstand high temperatures without breaking down. This makes it ideal for use in harsh environments or in applications where heat dissipation is a concern.
As FR4 material is one of the most affordable materials on the market, which makes it is a great option for businesses on a budget. In addition to being cost-effective, FR4 material is also easy to work with, which can save time and money during the manufacturing process. It can be machined in a variety of ways, including deep draw and laser cutting, so customers are not limited in their design options
FR4 material is a great choice for PCBs because it offers good electromagnetic shielding. This means that it can help protect your circuit from outside interference. Additionally, FR4 is flame retardant, which makes it a safer option for use in electronic devices. It’s also strong and durable, so you can trust that your PCB will last for years to come.
It’s important to note that there are many different grades of FR4 material with different properties, so make sure you know what you need before ordering.

Some things worth considering when choosing an FR4 grade include: whether the PCB needs to support weight, how sensitive the device will be to temperature changes, how strong it needs to be, and how much flexibility is required.

Understanding PCB and Its Materials

Printed circuit boards manufacturers involve many steps, including design and finishing, leading to a huge production. Printed Circuit Board designers and engineers should consider the material in terms of its properties and applications. They should have it in Gerber files before sending the PCB design for manufacturing. In other words, PCB material determines the end product. Various PCB materials include the FR4, Teflon, PTFE, etc.
PCB substrates are made of phenolic and proxies, whereas PTFE is more costly than all others. Different PCB materials are available in the market, and you should choose them according to your needs.

Types of PCB Materials

Mostly PCB has four layers which are made one by laminating through a heating process. Each layer hasa specific PCB function and needs a specific material. PCB designersshould have full knowledge of materials in terms of their properties which should be suitable for specific applications.The end product with PCB is a specific device that needs a specific material, so it is a crucial factor.
PCB is composed of different materials from the base to the top, including copper, substrate or base layer, copper, solder mask, and silkscreen.
The subsequent layer of PCB is copper which is placed and bonded over a base material with heat and adhesive. The thickness of the copper layer is used according to the PCB and its application. Like, you can make it in one or two layers, depending on your needs. Mostly, cheap devices or gadgets have PCBs with a single layer of copper.
Like FR4, copper used in the circuit boards has different types in terms of resin, such as PF resin, epoxy resin, and polyester resin.
On the other hand, the silkscreen layer helps make marks or letters for programmers to read on a printed circuit board. The layer below a silkscreen is a solder mask and don’t forget to read our special post on solder masks.You can choose PCB materials by yourself or through an expert.

What is the FR4 Trace?

FR4 thickness is often 1oz,2oz, or 3oz, and the copper layer can be populated according to the design. It is also tested against the UV rays before removing the chemical solution to have correct copper traces which connect different parts on the FR4 PCB.
FR4 PCB trace can have signal issuesdue to mismatcheddriver’s and receiver’s impedance. Such an incompatibility results in bumps on the layer that reflects signals at a receiver’s end, sending them back to the copper trace.
The signal reflection that occurs due to mismatched impedance can affect the signal integrity. So, as a thumb rule, you should be careful, especially if the edge rate is lower than 1/6 of the propagation gap or delay in the copper trace’s length.
In the case of copper trace, signals occur 1 inch in 6 ns. You must take care of measurements to manage the impedance, especially if the edge rate is 1ns, whereas the copper trace is larger than one inch.

Printed Circuit Board FR4 Material
Printed Circuit Board FR4 Material

How To Manage The FR4 Trace Impedance

  • You can use resistive matching to make the driver and receiver’s impedance compatible. Such a technique involves a resistor having a value according to the source impedance. The resistive is set parallel with the receiver or in a series, depending on the requirements.
  • Some other techniques also help in this case, minimizing the signal reflection. A long PCB trace causes high-signal reflection. So, you can also reduce the trace length in a circuit board to overcome the signal reflection.
  • A signal’s return path is also important in this case because impedance can happen anywhere, including the signal trace or returning path.
  • If PCB has high-frequency signals, you should route the traces on the plane of a returning path. But, don’t route signals on a split plane because it would result in a discontinued impedance.
  • You must use advanced PCB design or analysis techniques to get precise results. The tools should possess advanced simulation.

Wrap Up

FR4 material is the standard fiberglass laminate that you’ll find in all PCBs (printed circuit boards). It has many uses, and each one will likely have its own set of requirements for using FR4 material. You’ll need to keep your specifications in mind when looking at FR4-based materials, but this will give you a good idea of what kind of FR4 laminates are available on the market today.
The FR4 board can be easily cut with a knife or saw and drilled through using a drill press or electric drill. You can even shape it using files or sandpaper if you need to, which makes it versatile as well as economical. So if you’re looking for high-quality circuitry in your next project, take a good look at what this particular type of PCB has to offer before making any decisions.
Would like to know more about the FR4 material or PC Board assembly? Email us at sales@pnconline.com

Metal Core PCB Design & Manufacturing Concepts

Metal Core PCB Design & Manufacturing Concepts

Circuit board fabrication, PC Board, PC Board fabrication, printed circuit board assembly, Printed Circuit board Fabrication, printed circuit board manufacturers, , , , ,

Metal core PCB consists of a layer of thermal insulation, copper foil, and metal plate, and you can also call it MCPCB. The basic benefits of metal core PCB include:

  • High magnetic conductivity
  • Great heat dissipation
  • Excellent mechanical strength
  • Easy processing

The base layer of the MCPCB is copper and aluminum, and you can choose to have any of them. Aluminum PCB is cheaper than copper, and you would find them in LED lights, mobile phones, and audio-frequency equipment. However, copper is better than aluminum in terms of performance. MCPCB was developed to overcome the heat dissipation issues occurring in high-power LED lights.

Things To Consider While Designing The Metal Core PCBs

The construction of the MCPCB stack-up depends on certain guidelines that we will discuss here. Such boards consist of a specific base layer, such as aluminum, copper, or even steel. You will have to determine the layer arrangement after selecting your desired metal and dielectric laminates. The type of the layer will determine other aspects, such as components and routing.
MCPCB has different types, depending on the number of layers as single-layer, double-layer, or multiple-layer metal core circuit board.

What Is A Metal-Backed PCB?

This Printed Circuit Board has a metal layer on its back, whereas the opposite layer has electric components. You can’t route traces on the back, however, through-holes are possible for routing between different dielectric layers, bringing ground to the metal substrate.

Metal Core PCB Routing

In the case of a double-side PCB, you can place through holes for routing between the metal core’s sides. You can use the multilayer dielectric stacks on the metal core’s sides to support different layers’ routing.You should ground the metal substrate for shielding, and to prevent it from acting as a monopoly antenna.

MCPCB Applications

Metal core circuit boards are ideal for aerospace and military industries that involve mechanical shocks, as well as high moisture and temperatures. So, MCPCB helps meet such requirements because they have a strong structure and a high thermal conductivity compared to PCB having an FR4. Such highly conductive circuit boards ensure an equal distribution of temperature when there is thermal cycling. So, it does not let the hot spots make closed components.
Metal core PCBs are also suitable for electric products which should work at high temperatures, such as high-current regulators, automotive electronics, and high-power LED lighting. The design of such applications depends on a precise stack up, and the board architecture should perform high at a low temperature.

Metal Core Printed Circuit board Fabrication Process

As there is a metal substrate in the stack up, such PCB involves a specific manufacturing process.You can use the FR4 dielectric in the case of a single-layer board by pressing the layer and bonding it to the metal plate.
If it’s a stack-up with a multilayer dielectric, you should first drill the metal core to have a layer transition independent of a short circuit. In the beginning, large holes are made and plugged with the insulating gels.Then, the gel has to be cured to make copper plating like a standard PCB. After that, you have to press and bond the remaining stack-up with the metal substrate. The stack-up needs through-holes followed by copper plating and residue cleaning.
The single-layer metal core circuit board has a metal base, copper layer, non-conducting or dielectric layer, solder mask, and IC components. Most thermoelectric separation applications consist of a COB or Chip-On-Board metal core circuit board,
It has two layers of copper conductor and both are on the metal core’s same side. Whereas the 2L MCPCB also has the metal core between two conductors, and designers call it a double-sided metal core circuit board.

Metal Core PCB Design & Manufacturing Concepts
Metal Core PCB Design

How to Select the MCPCB Components

It is essential to decide what components to choose when designing printed circuit boards as it can affect the final product. Such electronic components have different shapes and sizes, different power consumption specs, weights, and several other elements.
If you know how to choose PCB components efficiently, it can prevent big mistakes during design. We will help you in selecting the right components for your metal core PCB design.

You have to use certain design software tools to source the MCPCB components. These tools are necessary for all types of circuit boards, including a board with FR4, a rigid-flex circuit board, or a metal core board.
The surface mount technology is suitable for placing the components because it involves a minimum shorting to the metal substrate.You can also use the through-hole components,but you have to be careful to ensure that the solder mask does not get damaged on the back of the metal-backed PCB.
PCB fabrication involves multiple steps and the right design can enhance this process, preventing unnecessary design revisions.The manufacturer should have all documents having the fabrication details of the MCPCB.
Other than using metal cores, some passive techniques also help keep a circuit board cool through thermal management.

Designing MCPCB In A Closed Environment

The design of a multilayer PCB can become complex without compatible design software. You require the layout design tools for precise placement of the components, vias, routetraces, electrical, and thermal load crosscheck, etc.
You must have a good library of materials while designing the MCPCB. Likewise, the PCB layer-stack manager is required to handle your board’s structure. A suitable stack-up manager helps you to design a stack-up with an appropriate placement of the metal core, be it symmetric or asymmetric. Once the dielectric layers are defined, you need some groundwork for route traces and components’ placement.

Choosing The Design Software For PCB Layout

Different software help develop the PC Board layouts but make sure to choose the suitable one such as Altium. It helps you to have very precise CAD features to place the components. It also makes routing simple through special routing tools, whereas the layout engine helps ensure that the MCPCB is according to the design guidelines.
Remember that suitable software includes the 3-D design features to help you to design the complex mechanical parts of the MCPCB. You can also share your design with others through Altium 365, a cloud platform

Parameters of a Multi-Layer MCPCB

The design parameters of aluminum PCB sare described below.

  • Desired Aluminum thickness is 0.8-2.0mm
  • Solder resistance should be 288℃, >180 sec.
  • Breakdown voltage should be >3000v
  • The dielectric loss angle should be 0.03
  • Flammability should be UL 94V-0
  • Thermal conductivity should be 1.5W and 2.0W
  • Peeling strength should be >9lb/in

The minimum drilling diameter should be 1 mm in the case of an aluminum core, and the final diameter can be up to 0.3mm. There should be at least 1.2 mm spacing between the drill holes to avoid any damage.
Metal core PCB is also useful in several other areas having high mechanical loads where the dimensional stability should be high. Moreover, you can use it for electric vehicles, backlight units, automotive, audio systems, traffic lights, commercial buildings’ lighting, and solar panels.

Important Note

The digital devices depend on printed circuit boards for signals transmission to help them operate. These devices need a well-designed structure and manufacturing, but you have to encounter many issues in this case that we will discuss here. Circuit boards have different types and any issue in the design of a PCB would cause delays in its manufacturing, so you must know how to avoid them.

FAQs

What is A Metal Core Printed Circuit Board?
Metal core PCB has a metal base, such as aluminum, copper, or steel of which aluminum and copper are common.
Which One Is Cheaper, MCPCB with Aluminum or Copper?
MCPCB with aluminum is cheaper than copper. But, copper is better in terms of performance.
How Many Types of Metal Core Circuit Boards are there?
MCPCB has different types, depending on the number of layers, such as a single-layer, double-layer, or multiple-layer metal core circuit board.
Where Can I Use The Metal Core Circuit Board?
Metal core PCB is also useful for electric vehicles, backlight units, automotive, audio systems, traffic lights, commercial buildings’ lighting, and solar panels.

Wrap Up

There are several benefits of metal core PCBs, such as high magnetic conductivity great heat dissipation, excellent mechanical strength, and easy processing. The base surface of the MCPCB is copper and aluminum, and you can choose to have any of them. Aluminum PCB is cheaper than copper, and you would find them in LED lights, mobile phones, and audio-frequency equipment. But, copper is better than aluminum in terms of performance. Metal Core PCB was developed to overcome the heat dissipation issues occurring in high-power LED lights.
The design of a multilayer PCB can become complex without compatible design software. You require the layout design tools for precise placement of the components, vias, route traces, electrical, and thermal load crosscheck, etc.
Would like to know more about Metal Core PCB or pcb assembly services? Email us at sales@pnconline.com

Flexible Circuit PCB Assembly

Flexible Circuit PCB Assembly

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It can be tricky to figure out what you need to know about flexible circuits assembly, especially since it’s not something many people are familiar with or have experience with. Flexible electronic assembly is one of the most innovative and useful circuit boards in the electronics world since it allows you to make low-profile electronic devices with multiple electronic components.
The Circuit board has different types, including a standard or rigid PCB, a flex PCB, and a flex-rigid PCB. Besides, these circuit boards are further divided into single-layer PCBs, double-layer PCBs, and multilayer PCBs.
A flexible circuit board has a flexible base, but the components are just like a rigid circuit board. However, you can turn a flex PCB into any shape while using it which means it is easy to bend.The following article will help you learn everything you need to know about flexible smt assembly so that you can get started working on your designs right away.
Before we move to the assembly of a flex PCB, we want to discuss its applications.

FPCB Applications

The FPCB is a vital part of electronic products that we use daily, such as desktop printers, hard disks, and several other devices. You would see the use of a flex circuit board in the below industries.

  • Medical industry
  • Consumer electronics
  • Communications industry
  • Military
  • Automotive industry
  • Aerospace industry
  • Transportation

Engineers use it in the transportation industry because flex PCBs are vibration-resistant and constant movement for several hours can’t damage them.

Choosing The Right Material And Processes

When it comes to choosing the right materials and processes for your flexible circuit board assembly, there are a few things you need to keep in mind.
First, consider the environment in which the board will be used. Will it be exposed to harsh chemicals or extreme temperatures?
Second, think about the amount of flexibility you need. The more flexible the circuit, the more expensive it will be. Finally, consider the size and weight of the finished product.

What Are The Uses Of The Flex PCBs?

Every kind of circuit board has specific uses because it is an important part of different products, especially electronics. Designers preferflexible circuit boards for computers, mobile phones, and servers to make them more effective, less heavy, and more flexible. Though different devices have different shapes, functions, and sizes, they all include flexible circuit boards.
Let’s look at the main uses of flexible Printed Circuit Board
1-FPCB is Flexible

  • The flex circuit board is an elastic board that helps in placing it near folds or edges.
  • It is suitable for 3-axis connections due to its elasticity.
  • FPCB involves minimum wiring, whereas some applications don’t require any wiring at all. So, there are no wiring issues that make a device more reliable.

2-Flex PCB Reduces Weight and Space
Unlike rigid circuit boards, a flex PCB needs less space. According to engineers, it can save 60 percent of space, hence, its weight also decreases.
3-Flex PCB Reduces Connectors
If you use a flex PCB in a 3D design, it will eliminate or reduce connectors. Whereas the bending cycles go up to 200 000.
4-FPCB Eliminates Vibration
A flex PCB is very light which helps it absorb movements or vibrations. So, the vibrations can’t damage an FPCB. Moreover, the solder joints also stay safe.
5-Compatible With Tough Environments
You can use a flex circuit board in tougher environments due to its material. Its main materials are water-resistant, shock-resistant, heat-resistant, as well as corrosion, and oil-proof.
6-Thin layers
Flex PCB has thin layers on the inside which reduce its weight. The copper layers in an FPCB are heavy which if combined with thin layers becomes useful for high-power applications.

Types of Flex Circuit Board

A flex PC Board has different types, including single-sided, double-sided, multilayer flex, and rigid-flex circuit boards. Let’s look at their pros one by one.
Single-sided F PCB: It is economical, flexible, and has many bending cycles.
Double-sided F PCB: Its design is more flexible than others. Moreover, it saves space and provides dual-sided soldering.
Multilayer F PCB: It is lightweight and compact and its flexibility is more in a 3D design. It is compatible with blind and buried vias.
Rigid-flex circuit board: It helps have a long-lasting 3D application having stable parts, pins, heat streaks, etc. It reduces noise and enhances signal integrity.Besides, it is more reliable and offers better impedance.
It helps have minimum mechanical space and reduces the weight of the device. It is compatible with the HDI micro-via. It is economical and offers a flexible pcb design.
Some More Advantages
A flex PCB can give you many benefits, but mainly it enhances flexibility and saves space. Its assembly involves a few items that reduce its cost and manufacturing time.

  • A flex circuit board offers a high-heat dissipation.
  • It enhances the inner airflow.
  • It reduces the size and weight of the package.
  • It involves minimum assembly errors.
  • It reduces the inductance of wires.
  • A flex circuit board enhances the product’s looks.
  • The assembly time and cost of the FPCB are less in some cases.
Flexible Circuit PCB Assembly
Flexible Circuit PCB Assembly

Flexible Printed Circuit Board Assembly

The assembly of a flex PCB is the same as a rigid board except for a few changes due to certain technical needs. The assembly of a single-layer flex PCB consists of the following steps

  • BOM
  • Electrical testing
  • Punching process
  • FPCB baking process
  • Optical inspection
  • FQC process
  • Silkscreen printing process
  • Reflow soldering
  • Packaging process
  • Mounting process
  • Deep inspection

Flex To Rigid Surface
Since flex PCB is soft and gets deformed, it is hard to assemble it directly on SMT. So, engineers fix it on a hard surface such as a tray for the assembly process. The tray or a hard carrier should be well-intact to make assembly smooth.
Low-Density Assembly
Flex PCBs aremore costly than the rigid circuit board, so most of them are used for connecting different modules having different functions. So, the FPCB assembly involves fewer components in the case of low-density assembly. The quantity of the components ranges from 2 to 50 in this case.
Increased Panels
Manufacturers use many planes during FPCB assembly to enhance the process. A flexible circuit board is used in smart products, such as digital cameras and mobile phones, so a single board is too small. As it involves a few components, manufacturers use panels which are then removed through punching.
Use of Auxiliary Fixtures
Flexible PCB assembly involves auxiliary fixtures as it deforms easily. These fixtures include:

  • Baking fixture
  • Carrying tray for FPCB
  • Electrical and function test fixtures
  • Cutting Fixtures

High Demand for Quality
The devices with FPCB are used in an environment where the accuracy of control has to be high. So, the board components should be well-positioned to get compatible with a particular environment.One must focus on certain factors, such as anti-static precautions, cleanliness, and reliable soldering. It also involves several technical issues.
Increased Assembly Cost
A flex circuit board has a costly assembly compared to a rigid circuit board. It involves many fixtures which also increases its cost.Theassembly process takes more time than a rigid PCB. Moreover, the assembly involves lots of accessories and working labor because less equipment is used. Besides, the increased demand for high quality and flawless manufacturing environment also is the reason for the high cost.
However, as the flex circuit board’s application is increasing, so new technology and assembly methods emerge. Eventually, the assembly cost decreases due to less time and tools involved.
Choosing A Supplier
When it comes to choosing a supplier for your flexible circuits PCB assembly, there are a few things you need to take into account. First, you need to make sure that the supplier is reputable and has a good track record.
Second, you need to make sure that they have the necessary experience and expertise.
Third, you should ensure that they are able to meet your specific needs and requirements.
Fourth, you should see if they are able to provide you with a competitive price. Finally, you need to ensure that they can produce high-quality products at an efficient rate.
For example, some of the key considerations when selecting a supplier are quality control measures in place and their ability to adapt to changes in demand. To put this another way, if a company’s success relies on being able to keep up with production rates, it will be easier for them to fulfill orders if they’re accustomed to adjusting according to supply and demand than if they’re not. The same thing goes for quality control, as companies without established procedures may not be as adept at preventing defective products from reaching customers.

Final Words

Flexible circuits are used in a variety of products, from hearing aids to sports-related items like fitness trackers and smartwatches. They allow you to connect electronics into your home, and even onto your body, giving you easy access to valuable data and features. However, with all this flexibility comes the need for greater care in assembly than typical PCBs require. The designer must know about flexible circuits and PCB assembly to ensure the end product works correctly and lasts as long as possible.
Would like to know more about Flexible Circuit assembly or pcb assembly services? Email us at sales@pnconline.com

Ultimate Guide to PC Board Thickness

Ultimate Guide to PC Board Thickness

PC Board, PCB Design, PCB Fabrication, Printed Circuit Board, printed circuit board assembly, Printed Circuit board Fabrication, , , , ,

Printed circuit boards are vital parts of electronic technology and you have to focus on various factors to design or buy them. PCB thickness is the most important factor in this case. However, the weight, profile, and components of PCB also matter a lot.
PCB thickness can influence its function, affecting resistance and conductivity. The application of a circuit board determines its thickness and there are different levels of thickness in this regard.

A-Thickness Of A Standard PCB

A standard printed circuit board has different types, like one-sided having one layer of copper or double-sided boar with two layers of copper. Whereas multiple layers are also in practice. The double-sided PCB has a substrate layer between two layers.
Generally, a standard circuit board is 1.57mm or 0.0065 inches as it used to be the thickness of the plywood in old circuit boards. Later, multilayered PCBs emerged and the designer had to make their thickness according to the connectors. So, the designers need a standard thickness of 1.57mm.
The board thickness also ranges from 0.008 inches to 0.240 inches, and you can select any thickness between these figures to match the PCB application. You can give your requirements to the manufacturer or can hire an engineer to evaluate PCB thickness for a specific application.

Copper Thickness Of A Standard PCB

You also have to consider the copper thickness as it helps get the desired PC Board thickness and influences its function. Like, one square foot area of the circuit board needs an ounce of copper which becomes 1.37 mils. But, it can vary, depending on your needs according to the current that passes through the board.
Most circuits come up with 1oz copper i.e. equal to one ounce. However, it can be 2oz if the circuit board needs high currents. Designers often increase the track’s thickness which results in higher current points. Moreover, they don’t add anti-welding masks because they want to reinforce the track during assembly, like with tin.
Sometimes laminate manufacturers use an intermediate thickness of copper just to lower the price, like 0.75 oz. But, such a practice is technically not so good. Experts don’t recommend this because the PCB thickness also reduces during mechanical or chemical cleaning. The popular copper thickness is 0.5oz, like in the case of two-sided laminates.

Trace Thickness In PCB

You have to specify the trace thickness while making the Gerber files to avoid overheating. Trace thickness is the trace width that can tolerate the temperature difference ranging from the standard to maximum operating temperatures. In other words, the trace width should be enough to bear increased temperatures. Besides, PCB width calculators are available to find the trace width.

 

Ultimate Guide to PC Board Thickness
Thickness guide of PC Board

B-FR4 Thickness Of A Standard PCB

FR4 is the flame retardant material which is a fiberglass sheet with epoxy lamination. FR4 shows the quality of the laminate in PCB. Generally, it’s the base material for Printed Circuit board Fabrication.
The rigidity occurs due to epoxy that resists fire, and engineers prefer it for its low cost. The dielectric strength of FR4 is high, moreover, it is lightweight and also resists heat and water. So, they are compatible with different environments.
The FR4 thickness lies between 3 and 10 inches, and it can cause an increase in PCB thickness. You have to evaluate the FR4 thickness by considering the board components and space.
Design Parameters of an FR4 Board Thickness
Generally, the designers prefer thick boards because thin FR4 boards get damaged faster, especially when they are large, besides, the grooves are missing. Whereas thicker boards provide more flexibility and also include grooves.
Should Be Flexible
Thin circuit boards are more flexible than heavy or thick boards, especially in the medical field’s control unit. But, thinner circuit boards cause lots of issues during soldering that results in bending. Eventually, several other components also get curved, damaging a board’s connections.
Compatible Impedance
PCB thickness is crucial while constructing multilayer boards became you have to match the impedance. Besides, you also have to consider each layer’s capacitance. The board won’t function if its impedance is not compatible.
Edge Connectors
The edge connectors also directly influence the PCB thickness, especially when there is FR4. An incompatible mating part of the connectors can result in PCB damage. So, you must be clear about materials before PCB manufacturing.
PCB Weight
More thickness means more weight and increased shipping costs. So, you have to keep in mind the weight of the circuit board that determines the weight of the final product. Experts find thinner layers better than the others, however, one should go for a standard PCB thickness.
C- Core Thickness of Standard PCB
The core is a PCB layer having FR4 between copper layers or foils. The core of a standard PCB involves certain items of which copper should be precise. It’s a fiber mesh layer having resin, moreover, it has incurred FR4 as well.
The core thickness of the standard PCB becomes hard to select during a multilayer PCB design. However, sometimes PCB remains effective even if the core thickness is not compatible. But, the end product should perform high for which PCB should have accurate thickness. The designer must consider this factor and share the right details with the manufacturer.
The weight of the core thickness goes from 1 to 3 ounces depending on the requirements. The weight also includes copper layers that can be on both sides. However, if both sides’ weight differs, it would cause additional expenses and poor results. The core thickness with the desired copper weight is also possible through pre-preg sheets.
D-Two-Layered PCB Thickness
Printed circuit boards with multiple layers are getting popular these days. They include glass fabric based on epoxy having copper coils. A multi-layered PCB can bear high loads, however, its thickness remains only 63mm.
Complex PCBs need wiring, resulting in more layers, so PCB thickness becomes up to 93mm. The thickness of a standard PCB also gets influenced by foil lamination, if the lamination consists of 4 layers, 0.031 would be the PCB thickness. The thickness would become 0.062 if the foil lamination includes 6 layers.
Likewise, the thickness becomes 0.062 to 0.125 for 8 to 10-layer PCB. Your requirements can also demand half, one, or two-ounce copper foil.
PCB Thickness Allowance
Also known as PCB thickness allowance, it is the tolerance for PCB manufacturing substances. It can be more or less than the average amount of material. Designers consider certain parameters for it, such as the IPC guidelines. Such design parameters help manufacturers have the flexibility to develop a circuit board that performs well.

FAQs

What Is The Importance Of Knowing PCB Thickness?
You have to focus on the circuit board thickness because both electronic devices and boards have a tendency to shrink. So the board has to be thin and lightweight to help manufacturers place it into the device. The weight of the final product also matters as thicker circuit boards can increase the weight of the device, resulting in increased shipping costs.
How Many Layers Are There In A Standard PCB fabrication?
There are various types of standard printed circuit boards, including one-sided having one layer of copper or double-sided board with two layers of copper. There is also PCB with more than two layers called a multi-layered PCB.
What Is FR4 In A Standard PCB?
FR4 is the flame retardant material which is a fiberglass sheet with epoxy lamination. FR4 shows the quality of the laminate in PCB. Generally, it’s the base material of a rigid circuit board.
What Is Core Thickness In A Standard PCB?
PCB layer with FR4 between copper layers or foils is known as the core. The core of a standard PCB consists of various elements, including copper that has to be accurate. PCB core is a fiber mesh layer having resin, moreover, it has incurred FR4 as well.
What To Consider While Designing A Standard PCB?
Designers have to focus on various factors to design or buy a printed circuit board. PCB thickness is the most important factor, but the weight, profile, and components of PCB also matter a lot.
What is Trace Thickness In PCB?
Trace thickness is the trace width that can tolerate the temperature difference ranging from the standard to maximum operating temperatures. You have to specify the trace thickness while making the Gerber files to avoid overheating.

Wrap Up

Now, you know how important it is to consider PCB thickness in different ways. PCB thickness can influence its function, affecting resistance and conductivity. The application of a circuit board determines its thickness and there are different levels of thickness in this regard. You can have a good circuit board by choosing the board thickness wisely, depending on its application.
Would like to know more about printed circuit board assembly? Email us at sales@pnconline.com