PCB Material Types And Their Uses

PCB Material Types And Their Uses

PCB (Printed Circuit Board), also known as printed wiring board is the most important element of electronic assets. Be it a television, computer, or simply a calculator, manufacturing can’t take place without PCBs.

IBecause of their significant role, it becomes essential to choose to select the PCB material when manufacturing. This article discusses about different types of PCB materials you should know before you move towards PCB manufacturing.

Let’s explore!

What is PCB Material?

A PCB (Printed Circuit Board) tends to be a physical board that consists of conductive paths to the components and connects them electrically. It plays a crucial role in building electronic equipment. Different devices have different PCB materials, the most essential elements in PCB manufacturing.

There is a variety of insulating materials out there, which is used to manufacture the PCB layer. The very layer serves as the base on which electronic and electrical materials get placed. In order to build a well-functional PCB, you need to choose the PCB materials wisely, as it determines the overall quality and functionality of electronic products.

Detailed Description of PCB Materials

Now that we’ve come to know the basics, let’s get started with the further exploration of the types of PCB materials used to manufacture PCB. Here’s a detailed description you may love to know about:

Substrate/Base Materials

The substrate/base materials are the backbone of any type of PCB. They provide needed mechanical support, forming the structural foundation of the same. Mentioned below are the types of substrate materials that form the core of PCB manufacturing.

FR-4 (Fiberglass Reinforced Epoxy)

TIt’s made from woven fiberglass cloth and epoxy resin, and is also known as FR4, with the FR letters, which stand for “fire retardant.” It’s known for extraordinary mechanical strength, flame resistance, and mitigated moisture absorption. Although the thickness may vary based on the uses of a given board, this substrate layer tends to provide a robust foundation for PCBs.

FR-4 is typically utilized in consumer electronics and industrial control systems. It is widely used because of its compatibility with a variety of applications and its next-level cost-effectiveness.

CEM (Composite Epoxy Material)

CEM (Composite Expoxy Material) tends to be a blend of woven glass fabric as well as non-woven materials, such as paper. It is less durable as compared to the FR-4, however, the CEM-1 is one of the most commonly used and cost-effective versions. It is typically used to manufacture single-layer PCBs intending to build expensive products.

Polyimide

another type of PCB material, Polymide is high-performance with competencies to withstand extreme temperatures which may be up to 250°C. There are many benefits, however, the superior flexibility and stability make the very type of material most suitable when it comes to manufacturing products for automotive and aerospace.

PTFE (Teflon)

This very type of PCB manufacturing material provides next-level electronic properties and minimal signal loss. It is an excellent choice for manufacturing high-frequency RF (radio frequency) and microwave circuits. Although it has many benefits, this particular PCB material is expensive and difficult to process in comparison to other materials.

Copper Layer

The next type of PCB material in this blog, Copper foil tends to be laminated onto the substrate intending to form the conductive paths or traces. We measure copper thickness in ounces per square foot, for example, 1 oz/sq ft is around 35 µm thick. Different types of PCBs, such as single-layer, double-layer, and multi-layer are likely to have different amounts of copper as per the complexity of the circuit.

Soldermask

The green color you find in the motherboards is the color of soldermask. It is a protective coating that is applied over the copper traces. Not nearly common, however, the soldermask also sometimes appears in many other colors like blue and red. Soldermask is also known by the acronym LPISM, standing for liquid photo imageable soldermask.

The preliminary aim of soldermask is to circumvent oxidation, corrosion, and unintended soldering while the manufacturing procedure. They enhance the overall appearance of the PCB and electrical performance. For many years, the incidences of this have become more common just because of a lack of soldermask. Because of its attributes, most of the users generally prefer boards with soldermask.

Silkscreen Layer

It is the topmost layer that is printed on the PCB and is intended for component identification and assembly guidance. The silkscreen layer includes reference designators, logos, symbols, and instructions. Generally printed in white ink, however, it may use other colors depending on the type of design and manufacturing requirements.

Conductive Adhesives and Epoxies

These types of PCB manufacturing materials are used to connect components without traditional soldering. They are often used for flexible PCBs and in specific circumstances where lower thermal stress is needed. Examples of conductive adhesives and epoxies involve silver-loaded adhesives for the next level of conductivity.

Other Insulating Materials

• Aluminum-backed PCBs:

  These types consist of a metal core layer, usually aluminum, used to enhance thermal conductivity.

• Ceramic PCBs:

  They provide excellent heat dissipation and are made use of in high-frequency applications, for instance, LEDs and power electronics.

• Rogers Materials:

  These materials tend to be high-frequency laminates with superior dielectric properties that are often used in telecommunications and aerospace.

PCB Layer Technical Terms

Besides knowing the types of PCB materials, you should also have the know-how of the technical terms that are used in PCB manufacturing. Mentioned below are some crucial terms to know about the terms used in PCB manufacturing:

• Drill hit:

  Whether correctly placed or misplaced, Drill hit describes all the holes on the PCB. There are scenarios where a hole may be incorrect just because of dull drilling equipment used during manufacturing.

• Annular ring:

  It’s the very copper ring, surrounding all the holes on a PCB.

• DRC:

  It is an acronym for design rule check. DRC tends to be a practice to check the design PCB to measure its functionality. It includes checking the width of traces, drill holes, and the like.

• Mouse bits:

  Mouse bits are the PCB section, overly drilled to the point where it tends to threaten the board's structural integrity.

• Finger:

  It’s metal exposed along the board edge, serving as connecting points between two PCBs. You can find fingers mostly in old memory cards and video games.

• Pad:

  It is a certain area of exposed metal on a PCB on which a soldered piece is applied.

• Panel:

  A panel is a large circuit board made of smaller boards, which is eventually separated for individual uses.

• Surface mount:

  It is a method by which external parts are mounted to the PCB through holes.

• Paste stencil:

  A metal stencil on a PCB, onto which paste is applied for soldering.

• Plane:

  A wider section of exposed copper on a Printed Circuit Board, which is marked by borders but lacks a path.

• Plated through hole:

  It is the kind of hole that goes straight through a PCB. The purpose of this is to connect other components. The hole is plated and features an annular ring.

• Slot:

  Any hole that is not necessarily circular. PCBs having slots are often high priced because of the production expense of creating odd-shaped holes on a circuit board. Slots are generally not plated.

• Trace:

  It is an ongoing line of copper across a PCB.

• Via:

  A kind of hole through which signals tend to travel between layers.

PCB Materials And Their Applications Across Industries

PCB materials are manufactured in single and double-sided verities for application in the aerospace, military, medical, and automobile industries. Some of these use aluminum while a few of them are copper-clad. In all the above-mentioned industries, these materials are used aiming to ensure maximum performance in particular areas. For example, PCB core materials are selected specifically for their lightweight quality in specific industries, while can be used in others for their their competencies to handle increased amounts of power.

Conclusion

That’s all about there’s to it! This article discussed about types of PCB materials used to manufacture PCBs. From FR-4 to CEM, polyamide, and so on, through this article, you’ve got all the information you might need for the types of PCB material used when they are manufactured. Now, that you know all, if you’re thinking of manufacturing PCB, contact our experts and get it done with maximized convenience!