Designing printed circuit boards (PCBs) is a regular task for most electronics engineers (EEs). Have despite a vast number of years of experience in PCB designing, it is not easy to create a high-quality performance-driven PCB design. There are many factors that need to be taken into consideration, and board material is one of them. The basic material used to fabricate PCBs is of immense importance. Prior to fabrication, it is essential to consider the performance of materials in various aspects such as flexibility, temperature resistance, dielectric constant, dielectric strength, tensile strength, adhesion, and many more. The performance and integration level of the circuit board is entirely dependent on the material being used. This post explores more about PCB materials. So, stay tuned to know more.
Which Types of Material is Used for PCB Fabrications?
Here is the list of primary materials used for fabrications of circuit boards. Let’s take a look into it.
- FR-4: FR is an abbreviation for FIRE RETARDENT. For all types of PCB fabrication, it is the most commonly used PCB material. A glass-reinforced epoxy laminate, FR-4 is constructed using woven fiberglass, and a flame retardant resin binder. This material is extremely popular for providing excellent electrical insulator and possesses good mechanical strength. The tensile strength offered by this material is very high. It is well-known for its good fabrication and moisture absorption capabilities.
- FR-5: This substrate is made of woven glass reinforced material and an epoxy resin binder. It is a great option for a multi-layer circuit board design. It works exceptionally well during the lead-free soldering process and possesses excellent mechanical properties at high temperature. It is well-known for its low moisture absorption, chemical resistance, excellent electrical properties, and immense strength.
- FR-1 and FR-2: This comprises paper and phenol compounds and works phenomenally for a single-layer circuit board design. Both the materials possess a similar characteristic, but FR2 has a lower glass transition temperature compared to FR1.
- CEM-1: This material belongs to the group of Composite Epoxy Materials (CEM). This group consists of epoxy synthetic resins, woven glass fabric, and non-woven glass cores. This material is used for single-sided circuit boards and is inexpensive and flame retardant. It is known for its excellent mechanical and electrical properties.
- CEM-3: Similar to CEM-1, this is another type of composite epoxy material. It is flame-retardant and mostly used in double-sided circuit boards. It has lower mechanical strength than FR4 but is inexpensive than FR4. Thus, this is a good alternative to FR4.
- Copper: Copper is the first and primary choice for single and multilayer circuit board manufacturing. This is because it offers high strength levels, high thermal and electrical conductivity, and low chemical reactivity.
- High Tg: High Tg describes a high glass transition temperature. This PCB material is ideal for circuit boards used in demanding applications. The Tg material possesses high-temperature durability and long delamination durability.
- Rogers: Often called RF, this material is known for its compatibility with FR4 laminates. It allows easy lead-free circuit board processing owing to its high terminal conductivity and controlled impedance.
- Aluminum: This ductile and malleable PCB material prevents the copper circuit board from overheating. Mainly, it is chosen for its ability to dissipate heat quickly.
- Halogen Free Aluminum: This metal is a great choice for eco-friendly applications. Halogen-free aluminum possesses improved dielectric constant and moisture diffusivity.
PCBs have gained immense popularity over the years, and find large applications across industries which require complex circuitry. Thus, it is important to choose the correct PCB material as this will not only affect the features and functionality but also the overall cost of the board. The material is selected based on the application requirements, environmental factors, and several other constraints the PCB will face. If you have any doubts, then do contact an industry leader who will assist you for your electronic application. Rigiflex Technology is one reliable, trustworthy industry player specializing in single-layer, multi-layer, flexible, and rigid-flex PCBs.