ODM High Frequency PCB Solutions from China Suppliers - Factory Direct to Minimize Signal Loss and EMI Company, Factories
Product Description
▶ High-frequency PCBs are special printed circuit boards specifically designed to handle high-frequency signals (typically referring to frequencies above 500MHz or digital signal rise times less than 1 nanosecond).
📡 Communication infrastructure: Antennas, power amplifiers, filters, and low-noise amplifiers for 5G/6G base stations.
🚗 Automotive electronics: Millimeter-wave radar, advanced driver assistance systems, in-vehicle satellite communication.
✈️ Aerospace and national defense: Radar systems, electronic warfare equipment, satellite communication terminals, seeker heads.
🖥️ High-speed computing and data communication: High-speed server/router backplanes, optical modules, 400G/800G switches.
🔬 Test and measurement instruments: Network analyzer, high-frequency oscilloscope, signal source.
High-frequency signals are easily affected by the dielectric properties and losses of the substrate. Material selection is the core of high-frequency PCBs.
| Material Type | Key Parameters | Recommended Material / Specification | Applicable Scene |
|---|---|---|---|
| Base Material |
Dielectric constant (Dk) Dielectric loss tangent (Df) Coefficient of thermal expansion (CTE) |
High-frequency dedicated substrate • PTFE (polytetrafluoroethylene, Dk=2.1–2.6, Df≤0.0009) • Rogers series (e.g. RO4350B, Dk=3.48, Df=0.0037) • Modified epoxy resin (FR-4 high-freq version, Dk=3.8–4.2, Df≤0.01) |
PTFE/Rogers: Millimeter wave, radar, 5G base station High-freq FR-4: Consumer electronics (mobile phones, routers) |
| Copper Foil | Surface roughness | Low profile (LP) / Very low profile (VLP) copper foil, roughness ≤1.0μm | Reduce transmission loss on copper foil surface (skin effect) |
| Solder Mask Layer | Dielectric loss | High-frequency special solder mask oil (Df≤0.01) | Avoid increasing signal attenuation by the solder mask layer |
• The core of high-frequency PCBs needs to control characteristic impedance (e.g. 50Ω single-ended, 100Ω differential), with deviation ≤±5% (vs. ±10% for ordinary PCBs).
• Impedance calculation requires combining base material Dk, plate thickness, line width/spacing, and copper foil thickness — simulated via professional software (e.g. Polar SI9000).
• Example: RO4350B substrate (thickness 0.254mm), 50Ω single-ended impedance corresponds to a line width of approximately 0.8mm.
• Impedance compensation: Reserve ±0.02mm line width compensation for etching side erosion and solder mask coverage.
• Traces should be as short and straight as possible, avoiding right angles or acute angles (prone to reflection at high frequencies); fillet radius ≥0.5mm.
• Differential traces must have equal length and spacing (length difference ≤5mil), with ground wrapping (ground-to-differential distance ≤2× line width) to reduce EMI.
• Skin effect response: High-frequency current concentrates on the copper surface — use silver-plated copper foil or widen traces to reduce current density.
• Complete ground layer: Design a complete GND Plane — avoid ground layer segmentation; signal-to-ground layer distance ≤0.2mm to enhance coupling and reduce impedance.
• Shielding measures: Design metal shielding covers for sensitive RF areas; grounding must be reliable (multiple grounding points, spacing ≤λ/20).
• Heat dissipation: High-frequency devices (e.g. power amplifiers) require heat dissipation pads and metallized via arrays (via diameter ≥0.3mm, spacing ≤1mm).
• Device packaging: Prioritize miniaturized, low-parasitic packaging (e.g. QFN, LGA) to reduce signal reflection from packaging.
• Line width/spacing tolerance: ≤±0.01mm (vs. ±0.02mm for ordinary PCBs) — using high-precision Laser Direct Imaging (LDI) to replace traditional film exposure.
• Lamination accuracy: Interlayer alignment deviation ≤0.02mm; bonding temperature and pressure must match base material characteristics (PTFE requires high-temperature, high-pressure bonding).
• Etching process: Micro-etching technology reduces copper foil surface roughness; lateral erosion ≤0.01mm.
• Surface treatment: Prefer Electroless Nickel Immersion Gold (ENIG) or silver plating over OSP (organic film increases contact resistance); gold layer thickness ≤0.1μm to avoid increased loss.
