Multilayer PCBs are widely used in modern electronic products, especially in high-performance computers, communication devices, and consumer electronics. The thickness of multilayer PCBs is typically around 1.6 mm, but depending on the application requirements, they can be thinner or thicker. This article will provide detailed information about multilayer PCBs to help readers better understand their characteristics and choose the appropriate thickness.
What is a Multilayer PCB?
A multilayer PCB (Printed Circuit Board) is built on the basis of single or double-layer PCBs by increasing the number of conductive and insulating layers. Multilayer PCBs not only provide more electrical connections but also effectively reduce electromagnetic interference, improving the overall performance and stability of the circuit. This makes them essential in high-density wiring, high-performance, and miniaturized designs. As electronic products evolve towards smaller and more complex forms, the demand for multilayer PCBs continues to increase.
Factors Affecting PCB Layer Thickness
The thickness of a PCB is primarily influenced by the following factors: substrate thickness, prepreg thickness, PCB copper thickness, and solder mask thickness. These factors collectively determine the overall thickness of the PCB.
Substrate Thickness
The substrate’s thickness is a major factor in the overall PCB thickness. Different substrate thicknesses can meet different mechanical strength and electrical performance requirements. For instance, thicker substrates provide better mechanical strength and stability, while thinner substrates are suitable for applications with space constraints.
Prepreg Thickness
Prepreg is the insulating material between layers, directly affecting the overall PCB thickness. The choice and application of prepreg are adjusted according to design needs to ensure the insulating effect and bonding strength between layers.
PCB Copper Thickness
The thickness of each copper layer on the PCB also impacts the overall thickness. Usually, the copper thickness is designed according to the current requirements to ensure circuit reliability and conductivity. The thicker the copper layer, the greater the current it can carry, but this also increases the overall thickness of the PCB.
Solder Mask Thickness
Although the solder mask thickness is small, it still needs to be considered in some high-precision PCBs. The solder mask primarily protects the circuit from oxidation and short circuits and affects the PCB’s appearance and durability.
Layer Thickness for Different Numbers of Layers
Different numbers of PCB layers have different thickness ranges to meet diverse application needs. The following table shows the common thickness ranges for PCBs with various numbers of layers:
| Number of Layers | Common Thickness (mm) |
| Single Layer | 0.8, 1.0, 1.6, 2.0 |
| Double Layer | 0.8, 1.0, 1.6, 2.0 |
| Four Layers | 0.8, 1.0, 1.6, 2.0 |
| Six Layers | 1.6, 2.0 |
| Eight Layers | 1.6, 2.0, 2.4 |
| Ten Layers and Up | 1.6 – 3.2 |
These thickness ranges offer designers flexible choices to select the most suitable thickness based on specific design requirements, achieving optimal electrical and mechanical performance.
Importance of PCB Thickness
PCB thickness is crucial in the design and application of circuit boards. Thickness impacts not only the mechanical strength and thermal performance of the circuit board but also has significant effects on the following key aspects:
Signal Integrity
Different PCB thicknesses affect signal transmission speed and quality, impacting overall circuit performance. Thicker PCBs can reduce signal reflection and interference, maintaining signal integrity and stability, especially in high-speed signal transmission applications.
Mechanical Strength
Thicker PCBs have better mechanical strength, suitable for applications requiring high strength, such as industrial control equipment and automotive electronics. These applications demand high reliability from the PCB, and thicker boards provide better support and stability.
Heat Dissipation Capability
Thickness also affects the PCB’s heat dissipation performance. Adequate thickness can better dissipate heat, preventing overheating and ensuring stable circuit operation. Good heat dissipation is crucial for maintaining normal operation in high-power circuits.
Electrical Conductivity
PCB thickness affects the thickness of the copper layer, thus impacting electrical conductivity. Thicker copper layers can carry higher currents, enhancing circuit reliability and performance. For circuits requiring high currents, choosing the appropriate copper layer thickness is crucial.
Choosing the Right PCB Thickness
Choosing the right PCB thickness requires a comprehensive consideration of various factors, including application requirements, manufacturing constraints, and costs. For high-performance and high-reliability applications, careful evaluation of each factor is necessary to ensure the most suitable thickness is selected. Additionally, designers need to consider technical limitations and economic feasibility during the production process to balance performance and cost. By selecting the appropriate PCB thickness, product performance and reliability can be significantly improved, meeting the demands of various complex applications.
JY PCBA Multilayer PCB Production Capability
JY PCBA excels in multilayer PCB production, meeting various high-precision and high-performance requirements. Here is an overview of JY PCBA’s multilayer PCB production capabilities:
| PCB | Production Capability |
| Number of Layers | 1-24 layers |
| Maximum Panel Size | 558*670 mm |
| Minimum Board Thickness | 4 layers: 0.40 mm |
| 6 layers: 0.80 mm | |
| 8 layers: 1.00 mm | |
| 10 layers: 1.20 mm | |
| Minimum Line Width/Spacing | 0.065 mm |
| Minimum Line-to-Line Spacing to PSD | 0.09 mm |
| Minimum Line Width Tolerance | +/-10% |
| Minimum Finished Hole Size | 0.10 mm |
| Hole Wall Copper Thickness | Up to 35 microns |
| Maximum Copper Thickness in Pattern | 210 microns |
| PTH Hole Diameter Tolerance | 0.05 mm |
| NPTH Hole Diameter Tolerance | 0.025 mm |
| Aspect Ratio | 10:01 |
| Hole Position Accuracy | Minimum +/- 0.05 mm |
Conclusion
Multilayer PCBs play a crucial role in modern electronic products. Understanding and selecting the appropriate PCB thickness can significantly enhance product performance and reliability. By comprehensively considering application requirements, manufacturing capabilities, and cost factors, the most suitable PCB thickness can be chosen, achieving optimal design and production results.
JY PCBA is committed to providing high-quality, multi-layer PCB products, capable of handling complex designs from single-layer to 24-layer. We have advanced production equipment and stringent quality control processes to ensure that each circuit board meets the highest standards. Our production capabilities can meet various high-precision and high-performance needs, and we can flexibly handle customized production requirements. If you have related needs, please fill out the form below the article to contact us. We look forward to collaborating with you!
