The core thickness for JLCPCB's multilayer PCBs, particularly those designed for high precision with impedance control, is 0.7 mm. This specific dimension is crucial for maintaining signal integrity and overall board performance.
Understanding the PCB Core
In printed circuit board (PCB) manufacturing, the "core" refers to a rigid laminate material, typically made of fiberglass (FR-4) saturated with epoxy resin, that forms the foundational structural layer of the board. Unlike prepreg, which is an uncured or partially cured material that bonds layers together, the core is already cured and has a defined thickness.
For multilayer PCBs, the core serves as a base for copper layers, with additional copper and prepreg layers stacked above and below it to create the complete board stackup.
Core Thickness in JLCPCB Stackups
JLCPCB, a popular PCB manufacturer, offers specific core thicknesses as part of their standard and advanced PCB fabrication options. For designs requiring precise control over impedance, the material properties and thickness of each layer, including the core, are meticulously selected.
Here's a breakdown of the core's thickness:
| Layer | Material Type | Thickness |
|---|---|---|
| Core | Core | 0.7 mm |
This 0.7 mm thickness is a critical parameter for engineers and designers, as it directly influences:
- Impedance Control: The dielectric constant and thickness of the core material are key factors in calculating the characteristic impedance of traces on the PCB. Accurate core thickness ensures that high-speed signals maintain their integrity.
- Mechanical Stability: The core provides the primary structural rigidity to the PCB, preventing warping and ensuring the board can withstand assembly processes and environmental stresses.
- Thermal Management: The core material's thermal properties contribute to the overall heat dissipation of the PCB, which is vital for reliable operation of electronic components.
Importance for PCB Design
When designing PCBs, especially those for high-frequency applications or with strict signal integrity requirements, knowing the exact core thickness provided by the manufacturer is essential. This information allows designers to:
- Accurately model transmission lines: Using specialized impedance calculators that factor in core thickness, copper thickness, and dielectric constant.
- Optimize layer stackup: To meet performance goals while adhering to manufacturing capabilities.
- Ensure manufacturability: By designing within the manufacturer's specified tolerances for material thicknesses.
For more information on JLCPCB's services and capabilities, you can visit their official website: JLCPCB.com.
