How to Choose the Thickness of PCB

First, in the world of electronic products, the PCB is often referred to as the "heart", it connects everything together making the board thickness an important parameter for this crucial component. Whether the PCB thickness is appropriately selected directly affects the performance, stability, and reliability of the final electronic products.

The process of selecting PCB thickness is influenced by various factors, such as product application scenarios, board material, and number of copper layers. Therefore, these factors must be comprehensively considered when selecting the PCB thickness.

Characteristics and Application of different PCB thicknesses

The most commonly used PCB thicknesses are 0.4 mm, 0.6 mm, 0.8 mm, 1.0 mm, 1.2 mm, 1.6 mm, 2.0 mm. PCBs of varying thicknesses will have varying effects on the circuit performance.

Ultra-thin PCB (below 0.6 mm)

Ultra-thin PCBs are lightweight, soft, and easy to bend, making them suitable for products that require a high level of space efficiency, such as :

• Smartphones and tablets

• wearable devices

• Robotics

• Laptops

• Drones

These products require very thin and light PCBs, so using PCBs with ultra-thin thickness can meet the needs. However, ultra-thin PCBs have relatively weak load-bearing capacity and are not suitable for applications requiring heavy components.

Mid-Range Thin PCBs (0.6-1.6 mm)

The mid-range PCB has a good balance between thickness and load-bearing capacity, making it suitable for a wide range of electronic products, including computer motherboards and home appliance control boards. The stiffness and stability of the mid-plate are moderate, which makes it suitable for most application scenarios. Compared to other thicknesses, the price of mid-board is relatively low and more economical. At JLCPCB, PCBs with thicknesses 0.8mm to 1.6mm start at only $2.

The most common PCB thickness for FR-4 substrates in the electronics industry is 1.6 mm (approximately 62 mil), also known as the standard thickness. It is typically used for general applications, including consumer electronics, smart homes, and industrial controls. These applications do not require particularly high mechanical strength or conductive properties, so the default thickness is considered sufficient.

Thicker PCBs (above 1.6 mm)

Thicker PCBs offer high load-bearing capacity and stiffness, making them suitable for electronic products that require the carrying of high-power and heavy components. Thicker PCBs are also suitable to be exposed to harsh environments. These applications include :

•    Industrial control boards

•    Automotive circuit boards

•    Aerospace

•   Railway transportation

These applications require PCBs with high mechanical strength and durability.

They are also used for PCBs with large outline dimensions, where regular thickness PCBs would start to deform and bend. However, thick boards are relatively expensive and challenging to process.

Key factors affecting PCB thickness:

1. The number of PCB layers: The more copper layers a circuit board has, the greater its thickness will typically be.

2. Signal type: Circuit boards carrying high-power signals typically require thicker copper layers and wider traces, while circuit boards in low-power environments can be thinner.

3. Material selection: Different materials have varying thickness characteristics, and selecting different materials can impact the thickness of the circuit board.

4. Operating environment: In harsh environments (e.g., high vibration or mechanical stress), thin or flexible boards may not be the most suitable choice. Thicker copper traces, however, have greater thermal mass and better heat dissipation, making them more suitable for high currents and temperature variations.

5. Copper Thickness: The overall thickness of the PCB is influenced by the thickness of the copper layers it has. Thicker copper layers, such as 2 ounces or 3 ounces of copper, have a greater impact on the overall thickness compared to thinner copper layers. Contribute more than one ounce of copper.

6. Special requirements: Certain applications may necessitate customized circuit board thickness, such as high-density boards or circuit boards used in unique environments.

How to Choose the Appropriate PCB Thickness

When selecting a PCB type, you need to consider whether the thickness of the circuit board is suitable for the application requirements. Generally speaking, when choosing the thickness of a PCB, the following factors should be considered:

Clarify application needs and performance requirements: Before selecting the PCB thickness, it is important to have a clear understanding of the application performance requirements, various different scenarios, and component load-bearing requirements. This will ensure that the chosen thickness is able to meet the product's specific requirements.

Safety of the circuit board: If the circuit board must handle high voltage or high current, a thicker PCB is recommended to ensure safe operation and adequate clearance/creepage distances.

Mechanical properties of the circuit board: If the circuit board needs to withstand high mechanical influence, it is advisable to choose a thicker PCB to ensure its mechanical strength

Production cost: Thicker the PCB, the higher production cost. Therefore, when selecting a PCB, it is important to ensure product performance while also considering the maturity of production technology and the cost of the PCB thickness.

Generally speaking, the expected turnaround time for receiving custom PCB layer thicknesses is longer due to the unusual thickness specifications.

Conclusion:

Choosing the appropriate PCB thickness is a crucial factor in ensuring optimal board performance and reliability. Taking into account factors such as engineers' application needs, cost, and manufacturing capabilities, JLCPCB acts as a PCB manufacture and supports PCB production from 1 to 20 layers and offers a thickness range of 0.7mm to 2.5mm.Engineers can choose the appropriate thickness based on their specific requirements. Whether standard FR-4 or specialized materials are required, JLCPCB can provide customized solutions to meet specific thickness requirements.

PCB Thickness Selection FAQ

1. What is the standard PCB thickness?

Answer: The most common PCB thickness for FR-4 substrates in the electronics industry is 1.6 mm (approximately 62 mil), also known as the standard thickness. It is widely used for general consumer electronics, smart home devices, and industrial controls.

2. When should I choose an ultra-thin PCB (below 0.6 mm)?

Answer: Ultra-thin PCBs are ideal for applications requiring minimal space and lightweight design, such as smartphones, tablets, wearable devices, laptops, drones, and robotics. However, they have lower load-bearing capacity and are not suitable for heavy components.

3. What are the main factors affecting PCB thickness selection?

Answer: Key factors include: number of layers, signal type (high-power signals need thicker boards), material choice, operating environment (harsh conditions favor thicker boards), copper thickness (thicker copper increases overall thickness), and special requirements like high-density designs.

4. Why choose a thicker PCB (above 1.6 mm)?

Answer: Thicker PCBs provide higher mechanical strength, better load-bearing capacity, and greater durability, making them suitable for high-power components, industrial control boards, automotive electronics, aerospace, and large-outline boards that resist deformation.

5. How does the operating environment influence PCB thickness choice?

Answer: In harsh environments with high mechanical stress, vibration, or extreme temperatures, thicker PCBs are preferred for better stability and durability. Ultra-thin or flexible boards may not withstand such conditions, while thicker copper also improves heat dissipation under high currents.