What is a Printed Circuit Board Made of?
PCB boards are the most important elements that have become essential to use in all modern electronic gadgets. There are many different types of PCB materials that make them special to use in specific electronic devices.
In fact, they are the basis of all electronic devices and without them, electronics can’t even function.
Read this guide thoroughly as it will ideally reveal the popular types of PCB boards. Moreover, you will also learn about the FR4 PCB material and the pros of its usage for high-power LEDs.
Let’s start from the basics!
What Exactly are PCB Boards?
Basically, electronic designers use the PCB boards to electrically connect and mechanically support all the electronic components with the help of
- Conductive tracks,
- And several other features,
that are etched from one or more sheet layers of copper laminated onto or between sheet layers of a non-conductive substrate.
How Many Layers can a PCB Have?
Essentially, a PCB board can have two or even one layers of copper. These kinds of PCB boards are actually helpful to use in simple applications. But for applications that are high-density,
PCBs can have up to fifty layers or even more than that.
How Many Basic Components does a Standard PCB Have?
In fact, there are 6 basic components that a standard PCB have such as;
- Solder mask
- Copper foil
- And final finish.
Actually, a prepreg is a very thin glass fabric. This glass fabric is specially coated by using dried and resin. Moreover, this glass fabric is coated inside special machines called prepreg treaters.
Usually, laminates are called copper-clad laminates. Further, these laminates are especially composed of sheets of prepreg. These sheets are laminated together using pressure and heat, with sheets of copper foil on every side.
A soldermask is a specific green epoxy coating that helps to cover the circuits on the outer layers of the board. Basically, a soldermask helps to provide protection to the conductors on the outside of the PCB.
It is a special type of negative electrolytic material. Moreover, it is deposited on a base layer of a PCB to form continuous metal foil. It is also popular as the conductor of PCB.
Nomenclature is generally popular as another name like silkscreen. Basically, the nomenclature is specific white letters that you usually see on top of the soldermask coating on a PCB.
Actually, the surface finish in a PCB is vital to the end product. Furthermore, there are several options to choose the final finish. These are essential to use for preserving, as well as enhance, soldering and bonding through all levels of interconnection.
What are the Types of PCB?
Basically, there are several types of PCBs. But PCB manufacturers actually use 3 main ways for their construction such as;
- Single-sided PCB boards,
- Double-sided PCB boards,
- Multilayer PCB boards.
Moreover, on the basis of several layers as well as the different types of PCB materials, you can find the following main kinds of PCB boards in the market;
- Single-Sided PCBs
- Double-Sided PCBs
- Multilayer PCBs
- Rigid PCBs
- Flex PCBs
- Rigid-Flex PCBs
- High-Frequency PCBs
- Aluminum Backed PCBs.
Hence, you can easily select the type of PCB boards on the basis of your requirements related to your project.
Which Methods do PCB Mmanufacturers Use for Creating Different Types of PCBs?
In fact, manufacturers electrically connect all the necessary components with the PCB boards by using 2 different methods. These popular 2 methods are:
- Through-hole technology
- Surface mount technology (SMT)
What are the Different Types of PCB Materials?
Basically, using the perfect material for creating PCB boards is highly important. There are several types of PCB materials that PCB designers use. Moreover, it is extremely important to consider the performance of the material in terms of,
- Temperature resistance,
- Dielectric strength,
- Tensile strength,
- Dielectric constant,
as well as several other physical, electrical, and thermal factors. You should always select the perfect material for fabricating PCB boards because their performance totally depends on the material that is used to fabricate them.
Different types of PCBs need different types of materials for their fabrication.
Which 3 Types of PCB materials are Used in Fabricating PCBs?
Actually, there are 3 major types of materials that PCB designers use for the fabrication of PCBs such as;
- PTFE (Teflon)
What is the PTFE (Teflon) Material?
In fact, PTFE is a special kind of plastic material. Furthermore, it does not provide any resistance so PTFE is ideally used for high speed and high-frequency applications. Additionally, it is highly flexible and hence this specific quality makes it ideal for those electronic applications that need tight tolerances.
Moreover, it is extremely lightweight and increasingly used in different types of PCBs. Since it is extremely lightweight so ideally used across various industries. Basically, PTFE is flame resistant, can exhibit high physical strength as well as can provide perfect temperature stability.
So, all these good features make it ideally versatile to use in different applications.
What is FR4 PCB Material?
It is one of the most common materials that PCB manufacturers use in fabricating PCB boards. Essentially, it is a special type of glass-reinforced epoxy laminate sheet. This special type of epoxy that designers use is water-resistant as well as a flame retardant.
In addition, FR-4 material also can provide good strength -to-weight ratios. The tensile strength that FR-4 provides is extremely high.
What is the Disadvantage of Using FR4 Based PCB for High-power LEDs?
As we have already described that most of the types of PCBs designed by PCB manufacturers use FR4 material as their base. But it may not suitable to use in high-power LEDs.
Let’s see what is the disadvantage of using FR4 based PCB for high-power LEDs!
As you can see that the progress of PCB technology has paved the way for the creation of novel and innovative electronic products. All the progress in the LED industry has directly benefited from it.
But in the early days, in all the industrial sectors, the traditional fiberglass PCBs were extensively used. Nowadays, electronic designers use metalcore PCBs (MCPCBs) in the LED industry. They are actually the perfect type of PCB materials for the LED industry because FR4 PCBs generate more heat.
In fact, this is a major disadvantage of using the FR4 material. Further, it has an adverse effect on the functioning of the LEDs.
What is a Metal Used in Creating PCB Boards?
Basically, each type of PCB uses metal in its fabrication. Manufacturers still use the traditional materials of copper, aluminum as well as iron, etc.
They are very important types of PCB materials as they allow the use of Surface Mount Technology (SMT) for the integration of all components.
Moreover, all these metals provide great mechanical durability. Hence, the products that use metal base PCBs have a much longer shelf life.
Metal Core PCB
That’s why electronic manufacturers are increasingly using metal in almost all types of PCBs.
What are the Advantages of Using Metalcore PCB Boards?
Metalcore PCBs have several advantages over traditional boards such as they can provide,
- High-temperature stability;
- Better heat dissipation;
- Highly Improved durability;
- greatly light in weight;
- Much Longer operating life
- Increased LED density
- Ideally, cost-effective.
What Type of Plastic is PCB Made from?
Basically, PCB designers commonly use polycarbonate substrates for fabricating PCB boards. Polycarbonate substrates are one of the perfect types of PCB materials. Moreover, it is a composite material that has made from flame-resistant epoxy resin binder and woven fiberglass cloth.
Essentially, this ideal solution allows for the lamination of the copper sheets on one or both sides of the board.
Is the Resist Material Used for Making PCB?
In fact, the resist material that PCB manufacturers use is in the form of liquid photopolymer. Further, it makes use of epoxy or epoxy-acrylate resin technology. This special technology helps to coat the whole board with the material.
This particular material coat has the typical thickness of almost 20 microns over the copper and 30 microns over the bare board.
How do I Choose a PCB Material?
As there are several types of PCB materials from which you can easily select according to the needs of your application. Moreover, it is also very important for you to make sure that design requirements align with needed board capabilities.
Actually, when you need to handle high amounts of current width and spacing are highly important. All and all, the structural strength of the board is defined by substrate and laminate.
Types of PCB Base Materials
As stated above, there is a wide variety of types of copper-clad laminates and several designation systems, here are some selected from the National Electrical Manufacturers Association (NEMA) specification. The board manufacturer, however, may have to periodically work with not only this but other specifications as well.
It is a paper base impregnated with phenolic resin. The color is usually brown, the material is opaque. Getnax boards are intended for use in consumer electronics because they are cheap. Getinaks brand XXXRS can be cold cut. It is widely used in very cheap devices. Getinaks brand XXXP cannot be cut down. By special order, additives can be added to the resin, with which a self-extinguishing material of the FR2 brand (FR – flame retardant) is obtained.
It is a material with the same paper base but impregnated with epoxy resin. The color is most often yellow or white, more or less transparent depending on the thickness. The FR3 material is self-extinguishing and is widely used in household appliances.
This material is widely used because it combines high mechanical strength and good electrical properties. Strength is due to the structure of the glass fiber reinforced with polymerized epoxy resin. The material is translucent, the color is usually green. Epoxy fiberglass G10 is the most widely used.
GII grade material contains heat-resistant resin and can withstand higher temperatures than G10 grade material. Self-extinguishing materials FR4 and FR5 are used where these properties are required.
The copper foil used for foiling the base is produced by electrolysis and has a purity of 99.5%. The foil is available in various thicknesses. In the United Kingdom and the United States, thickness is indicated in ounces per square foot, while in other countries, it is indicated in micrometers (μm).
Standard foil thicknesses for the most widespread use: 1/2 oz / ft²= 17.5 microns; 1 oz / ft²= 35 μm; 2 oz / ft²= 70 μm. Recently, another product range has appeared – ultra-thin foil 5 microns. Its main fundamental advantage is a significant reduction in the undercutting of the edges of the conductors.
Materials for Printed Circuit Boards
PCBMAY manufactures printed circuit boards from high quality imported materials, ranging from typical FR4 to microwave materials and polyimide. In this section, we define the basic terms and concepts used in the design and manufacture of printed circuit boards. The section tells about very simple things, familiar to every design engineer. However, there are a number of nuances here that many developers do not always take into account.