If you're looking for the best material to use for your PCB, you're in the right place. In this guide, we will discuss all of the different types of PCB laminate materials available on the market today. We'll talk about their pros and cons, and help you decide which type is the right material for your project. So whether you're a beginner or an experienced engineer, read on to learn more about PCB laminates!
What is Laminate in PCB?
Electronics industry concept: digital circuit board with microchips over the schematic diagram
Laminate is a material that PCB manufacturers use to fabricate printed circuit boards. Plus, It is made of thin layers of different materials, typically bonded together with heat and pressure. The most common type of laminate is FR-04, which is made of glass-reinforced epoxy. And other types of laminate include FR-02 (polyimide), FR-06 (Teflon), and CEM-01 (ceramic).
The traditional four layers of a board are as follows: Substrate, Copper, Soldermask, and Silkscreen (from bottom to top). Also, the laminates are developed by curing under pressure and temperatures of cloth using thermoset resin to create the final piece of uniform thickness.
Laminate plays a critical role in the performance of a PCB. For example, it affects the electrical properties, thermal conductivity, and mechanical strength of the board. Therefore, it is important to choose the right type of laminate for your project.
Types of PCB Materials
Heap of PCBs isolated on white
The following are the main types of pcb laminate materials:
FR- stands for Flame Retardant and it is a glass-reinforced epoxy laminate. Plus, FR-4 is the most common type of pcb laminate material. Besides, it has good thermal conductivity and mechanical strength. However, it is not suitable for high-temperature applications.
When working with multilayer PCBs, you should choose a high-performance FR-4 laminate. Because the improved TG and decreased dielectric qualities make it more reliable, making it ideal for high-frequency circuits.
Copper Clad (CCL)
CCL, called copper-clad laminates, is a base material that has a layer of copper bonded to one or both sides. Plus, it is available in different thicknesses, with the thinnest being 0.0014”.
The reinforcing substance of the Copper Clad laminate is glass fiber or wood pulp paper. A CCL laminate is applicable for high-voltage circuits in most cases. Such as in the production of printed circuit boards (PCBs) or in the wiring of transformers.
Teflon is a fluoropolymer that has excellent properties, such as a low dielectric constant and loss tangent. Teflon materials are also resistant to chemicals, UV light, and high temperatures.
Manufacturing Teflon PCBs can be better as a dielectric material in capacitors and as heat-resistant insulation in high-frequency applications. It is also useful as a lubricant and for other non-stick applications.
Teflon materials are available in sheet form, and you can cut them into the desired shape with a CNC router.
High Tg Epoxy
It is ideal for multilayer PCBs. The material has excellent thermal and chemical resistance.
In applications where high humidity and extreme temperatures are present, Ultra High Tg Epoxy provides excellent electrical insulation. In addition, Tg EEPOXY is extremely adaptable, cost-effective, and flame resistant.
Polyimide is a type of polymer that has an excellent heat resistance and electrical insulation properties. Also, extreme environmental stability is a characteristic of this type of laminate.
Polyimide is applicable on both rigid and flexible circuit boards with high-density, bendable, or inflexible circuits. In addition, It also generates high levels of chemical, thermal, and mechanical properties. Besides, Polyimide laminates are useful in a wide range of industries, including automotive, aerospace, military, and consumer electronics.
BT Epoxy has good heat resistance and electrical insulation properties. The BT Epoxy laminate is often useful on lead-free printed circuit boards. Besides, it has excellent thermal, mechanical, and electrical properties. And it is also resistant to chemicals and flame.
PCB Material Properties Consideration
Printed circuit board populated with some components
When you are choosing pcb laminate materials, you need to consider the properties that are important for your application. Some of the most important properties to consider include:
Moisture absorption is the amount of water vapor that a pcb material can absorb under specified conditions. And the moisture absorption rate is important because it affects the dimensional stability of the pcb material.
Flammability is the ability of a pcb material to catch fire and burn. In truth, the printed circuit board industry uses a classification system to rate the flammability of pcb materials. The classifications are based on the results of the pcb material's UL 94 Vertical Burn Test.
*Methylene chloride resistance
Methylene chloride is a common solvent used in the pcb industry. And it is important to know the methylene chloride resistance of a pcb material because it can attack and dissolve some pcb materials.
High-tech electronic PCB (Printed circuit board) with processor and microchips.
The density of a pcb laminate material is important to consider because it affects the weight and thickness of the pcb.
*Time to Delamination
The time to delamination is the amount of time it takes for a pcb material to delaminate or fall apart. This is important to consider because it affects the strength and durability of the pcb.
The peel strength of a pcb laminate material is the amount of force required to peel the material off of the pcb. And this is important to consider because it affects the durability of the pcb.
The flexural strength of a pcb laminate material is the amount of force required to bend the material. This helps to determine the PCB's ability to withstand forces without breaking.
*Coefficient of Thermal Expansion (CTE):
The CTE of a pcb laminate material is the amount that the material expands or contracts when exposed to heat. This affects the thermal stability of the pcb, so it is important to consideit when choosing a pcb laminate material.
*Thermal Conductivity (k)
It is a measure of a pcb material's ability to conduct heat. Plus, the thermal conductivity of a pcb material is important because it affects the amount of heat that can be dissipated from the pcb.
*Decomposition Temperature (Td):
The decomposition temperature is the temperature at which the pcb laminate material begins to break down. Also, the Td is important to consider because it affects the long-term reliability of the pcb.
*Glass Transition Temperature (Tg)
The glass transition temperature is the temperature at which the pcb laminate material changes from a rigid state to a rubbery state. Plus, you can think of the Tg as the point at which the pcb laminate material becomes flexible.
Electronic circuit board PCB with excellent electrical properties
*Dielectric Loss Tangent (Tan δ)
The dielectric loss tangent is a measure of the pcb laminate material's ability to dissipate heat. Usually, different laminate materials have different dielectric loss tangents.
*Dielectric constant (Er)
It is a measure of the pcb laminate material's ability to store energy. This is important to consider because it affects the electrical properties of the pcb. The dielectric materials with lower constants are better.
The electrical strength of a pcb laminate material is a measure of its ability to withstand an electric field. Moreover, it is inversely proportional to the thickness of the pcb.
*Surface Resistivity (pS)
The surface resistivity of a pcb laminate material is a measure of its ability to resist the flow of electrical current. Plus, it is also proportional to the PCB's thickness.
*Volume Resistivity (p)
The volume resistivity of a board material is a measure of its ability to resist the flow of electrical current. Additionally, you can calculate it by multiplying the PCB's surface resistivity by its thickness.
What to Consider When Selecting Printed Circuit Board Material
Now that you know the basics of the printed circuit board laminate material, here are some things to consider when selecting the right one for your project:
Cost is always an important factor to consider when selecting any board material. You'll want to balance cost with the other factors on this list to find the best overall pcb material for your project.
Some printed circuit board laminate materials are more easily available than others. This is something to keep in mind when making your selection, as it may impact the cost and lead time of your project.
When it comes to the printed circuit board laminate material, performance is key. You'll want to consider factors such as thermal conductivities, dielectric constants, and more when making your selection.
Your pcb material's lead time can impact the overall timeline of your project. Be sure to factor this in when making your selection.
PCB Material Selection
SMD green multi layer printed electronic circuit board with microcontroller and components
Now that you've learned about the most popular PCB materials let's look at some of the alternative possibilities. Which one should you choose for putting together your PCBs, among the aforementioned options? There are many things to think about. Here are a few examples:
One of the pcb materials' key characteristics is its dielectric constant. Plus, this value indicates how much a material can slow down electrical signals, and it's important for high-speed applications.
Another pcb material consideration is its thermal performance. Will your application require soldering or other high-temperature processes? You'll need to make sure the pcb laminate materials you choose can withstand those temperatures.
Debugging electronics device. PCB witch microcontroller in electronics laboratory
Coefficient of thermal expansion (CTE)
The pcb laminate materials' CTE value is important to consider because it indicates how much the material will expand or contract when exposed to heat. In addition, different pcb laminate materials have different CTE values, so it's important to choose one that is compatible with your application.
The transition temperature is the temperature at which the pcb laminate materials' properties change. For example, some pcb laminate materials become brittle at high temperatures, so it's important to know the transition temperature of the material you're using.
The thermal conductivity of a pcb laminate material indicates how well it conducts heat. This is important to consider because it can affect the overall performance of your device.
The electrical performance of pcb laminate materials is important to consider because it can affect the overall performance of your device.
The flame retardance of pcb laminate materials is important to consider. Due to the fact that pcb laminate materials are often used in devices that generate heat, it's important to know how well the material can withstand high temperatures.
This includes both the thermal expansion coefficient and the water absorption of the pcb laminate material. Also, the dimensional stability of pcb laminate materials is important to consider because it can affect the overall performance of your device.
Higher glass transition temperatures (Tg)
This helps to improve the dimensional stability of pcb laminate materials.
This is important to consider if you will be soldering components onto your pcb.
Printed Circuits Material Suppliers
Close-Up a lead solder a pin of a LED and a transistor on a pcb board.
There are many printed circuit material suppliers that you can choose from. It is important to do your research to find a supplier that is reputable and offers good quality products.
Some of the most popular pcb laminate materials suppliers include:
- Rogers Corporation
When choosing a pcb laminate material supplier, it is important to consider the quality of their products, as well as their customer service and support.
You should also consider the lead time for delivery of pcb laminate materials, as this can impact your production schedule.
Once you have selected a pcb laminate material supplier, you will need to choose the specific material that you want to use for your PCB.
There are a variety of pcb laminate materials available on the market, and each has its own unique set of properties.
Abstract Central Computer Processors Concept. 3D illustration. Conceptual CPU on circuit board - PCB
In conclusion, PCB laminate materials are a key component in the manufacturing of printed circuit boards. They provide rigidity and strength to the board, and must meet specific requirements in order to ensure proper functioning of the PCB. There are many different types of PCB laminates available on the market, so it is important to select the right one for your application. Thanks for reading!