PCB Blog - What is copper clad laminate used for?

A PCB copper clad laminate is a composite material in which one or more layers of copper are laminated to an insulating substrate (usually FR-4). These copper layers can be chemically or physically immobilized on the surface of the substrate for subsequent circuit pattern transfer and etching processes. The primary function of copper-clad laminates is to provide electrical conductivity and support the connection of electronic components while ensuring thermal management and electrical performance.

The manufacturing process of PCB copper clad laminates generally includes the following steps:

Lamination: combining an insulating substrate with a copper foil, usually accomplished by heating and pressurization.

Lamination: Coating the copper layer with a photosensitive material for subsequent circuit pattern transfer.

Developing and Etching: Transferring the circuit pattern to the copper layer through exposure and chemical etching, removing excess copper to form the desired circuit.

Surface Treatment: The finished product is cleaned and coated with a protective layer to improve corrosion resistance and electrical properties.

Usage

1.Electronic communication field

Copper clad laminates are widely used in electronic products such as cell phones, computers, communication equipment and network equipment. Among them, cell phone is one of its most important application areas, and the quality of this material used in cell phones has an important impact on the performance and quality of cell phones.

2.Computer field

With the development of computers, the application of copper-clad laminates has gradually expanded and become an integral part of computer hardware. For example, it is widely used in hardware such as power supply boards, motherboards, expansion cards and memory modules.

3.Consumer Electronics

With the increasing popularity of consumer electronics, the application of copper-clad laminates in this field is gradually increasing.For example,it is used in products such as smart watches and smart homes.

4.Automotive Electronics

Automotive electronics is one of the future directions, and it is also widely used in automotive electronics such as in-vehicle entertainment systems,in-vehicle navigation systems and body control systems.

In PCB design, it is critical to choose the right copper-clad laminate material, which is related to the electrical performance, thermal performance and mechanical strength of the board. 

1.Material Types

Copper clad laminates are usually composed of resin sheets, copper foils and reinforcing materials, and the main types include FR-4, polyimide (PI) and metal-based copper-clad laminates, etc. FR-4 materials are widely used for their good mechanical strength and electrical properties, and are suitable for most applications. Polyimide laminates excel in harsh environments and are suitable for applications requiring high thermal efficiency and multi-layer designs.

2.Performance Requirements

Different applications have different performance requirements for laminates. For example, in high-frequency applications, low-loss and stable materials such as the Rogers series are required, while high-power applications need to consider thicker copper layers to cope with current loads. The designer should evaluate the required electrical and thermal properties to ensure that the material selection meets the intended function.

3.Physical Properties

When selecting a material, attention also needs to be paid to its physical properties, such as coefficient of thermal expansion, tensile strength and chemical resistance. These properties affect the long-term stability and reliability of the laminate, especially when working in high temperature or humid environments. For example, the thermal conductivity of a material affects heat dissipation, and too low a coefficient of thermal conductivity can lead to heat buildup and damage to the board.

4.Cost Considerations

Cost is an important factor in material selection. In mass production, the most popular FR-4 material is widely used because of its good price/performance ratio. Higher performance materials are usually more expensive and need to be selected wisely according to the project budget. In some cases, the long-term effectiveness and reliability of high-performance materials can provide greater economic benefits, despite their higher initial cost.

The role of PCB copper coating

1.Improve the conductivity of the circuit board

PCB copper coating can improve the conductivity of the circuit board to ensure the electrical connection between various components on the circuit board. The high conductivity of copper foil can reduce signal loss and resistance on circuit boards. In addition, the copper coating can also be used to form a large area of grounding or power layer to reduce electromagnetic interference and circuit noise.

2.Enhance the mechanical strength and corrosion resistance of circuit boards

PCB copper coating can enhance the mechanical strength and corrosion resistance of circuit boards. The copper foil has high strength and hardness, which can protect circuit boards from external pressure and wear. In addition, the copper coating can also prevent the circuit board from being affected by oxidation and corrosion, thereby extending the service life of the circuit board.

3.Reduce electromagnetic interference on the circuit board

PCB copper coating can reduce electromagnetic interference on circuit boards. Due to the high conductivity and low resistance of copper foil, it can form a complete grounding or power layer,effectively shielding the electromagnetic interference on the circuit board. This is very important for the normal operation of some high-frequency circuits.

Copper-clad laminate,as an important basic material for circuit boards, undertakes the four major functions of PCB conductivity, insulation, support, and signal transmission.