4-layer FR4 PCB is engineered for critical metro station signal monitoring controllers, where precision, durability, and electromagnetic compatibility (EMC) are essential for safe railway operations. With dimensions of 85mm×60mm and a 1.55ММ толщина, the board provides a compact yet robust platform for integrating microcontrollers, communication interfaces, and signal conditioning circuitry in automated control cabinets. Построено из FR4 material, it offers stable electrical insulation (Диэлектрическая постоянная εr = 4,5) and mechanical strength, suitable for operation in harsh railway environments with vibration, temperature fluctuations, and electromagnetic interference.
А 0.5Унция (18мкм) толщина меди on all layers balances fine-line routing density (minimum line/space: 50μm/50μm) with signal integrity, ideal for high-speed digital interfaces (НАПРИМЕР., CANbus, Ethernet) and low-power microcontroller circuits. А 4-архитектура слоя (2 Слои сигнала + 2 ground/power planes) minimizes EMI by isolating sensitive analog signals from digital noise, critical for reliable detection of train signals, track occupancy, and safety interlocks. А Зеленая маска припадки LPI protects against moisture and contaminants, Пока Белый шелкосный экран ensures clear component identification for maintenance in the field. А Соглашаться (Электролетное никелевое погружение) surface treatment provides a corrosion-resistant, solder-friendly finish (3-5μm nickel, 0.05-0.1μm gold), ensuring long-term reliability for both surface-mount (Пост) and through-hole (DIP) components.
- EMC/EMI Mitigation:
- Ground plane stitching vias every 5mm to reduce loop inductance and suppress radiated emissions.
- Guard traces with via fences around sensitive analog inputs (НАПРИМЕР., track circuit receivers).
- Ferrite beads and bypass capacitors on power lines to filter switching noise.
- Mixed SMT/DIP Assembly:
- SMT components (ICs, resistors, capacitors) for high-density digital circuitry.
- DIP connectors (НАПРИМЕР., DB9, RJ45) and relays for robust field connections and high-current switching.
- Thermal Management:
- Thermal vias under power components (НАПРИМЕР., regulators, drivers) to dissipate heat into ground planes.
- Copper pour areas for passive cooling, maintaining <40°C temperature rise under full load.
- High-Precision Fabrication:
- Laser direct imaging (LDI) for 50μm line/space accuracy in high-speed signal traces.
- Electroless nickel plating with ±10% thickness uniformity across all pads.
- Testing Protocols:
- 100% AOI inspection for solder mask coverage and silkscreen clarity.
- Flying probe testing for electrical continuity and isolation (≥100MΩ).
- In-circuit testing (ICT) to verify component placement and functionality.
- EMC testing per EN 50121-3-2 (railway electromagnetic compatibility standards).
- Compliance:
- UL 94V-0 flammability rating for FR4 material.
- RoHS and REACH compliant for hazardous substance restrictions.
- Track Circuit Monitoring:
Processes signals from track circuits to detect train presence and position, critical for block signaling systems.
- Level Crossing Control:
Controls safety barriers and warning signals at railway crossings, interfacing with sensors and relays.
- Train Detection Systems:
Monitors inductive loop detectors or axle counters to verify train movements and occupancy.
- Communication Interfaces:
Manages data exchange between control cabinets, central control systems, and onboard train electronics.
By integrating 4-layer EMI shielding, 0.5OZ copper precision, and ENIG durability, this PCB enables engineers to build reliable, compliant metro signal monitoring controllers. The mixed SMT/DIP assembly supports both high-density digital integration and robust field connections, while the compact form factor fits seamlessly into space-constrained control cabinets. Окреплен ISO 9001:2015 certification and compliance with railway standards, this PCB ensures consistent performance in the critical safety systems that underpin modern metro operations.
