1. Overview

Terminal strips and turret boards are fundamental components in electrical and electronic systems, providing secure and reliable connections between wires, circuits, and devices. Terminal strips (also known as terminal blocks or connection terminals) are modular units with insulated frames that secure two or more wires together. Turret boards are specialized PCBs (Printed Circuit Boards) with raised metal posts (turrets) for high-density soldering of components or wiring. These components are critical in industrial automation, telecommunications, and power distribution systems due to their durability, ease of maintenance, and scalability.

2. Main Types and Functional Classification

Type	Functional Features	Application Examples
Screw Terminal Strips	Mechanical clamping via screws; suitable for high-current applications	Industrial machinery control panels
Spring Clamp Terminal Strips	Tool-free wire insertion; vibration-resistant	Building automation systems
PCB Terminal Strips	Direct PCB mounting; compact design	Consumer electronics power supplies
Turret Boards	Multi-layer PCB with copper turrets; supports wire wrapping or soldering	Telecom backplanes, military equipment

3. Structure and Components

Terminal strips typically consist of:

• Insulating housing: Made from thermoplastic or ceramic materials (e.g., PA66, PBT) for dielectric strength
• Conductive elements: Brass or phosphor bronze contacts with plating (e.g., tin, silver) to reduce resistance
• Clamping mechanism: Screws, springs, or push-in levers for wire retention

Turret boards feature:

• FR4 or Rogers high-frequency laminates with 2-10 layers
• 2.54mm or 5.08mm pitch copper turrets plated with gold or tin
• Through-hole vias for signal/power routing

4. Key Technical Specifications

Parameter	Typical Range	Importance
Rated Current	1A - 30A	Determines power handling capacity
Dielectric Strength	500V - 6kV	Ensures safety isolation
Contact Resistance	<1m	Impacts signal integrity
Wire Gauge Range	26AWG - 4AWG	Dictates application flexibility
Operating Temperature	-40 C to +120 C	Defines environmental robustness

5. Application Fields

• Industrial Automation: PLC cabinets, motor drives
• Telecommunications: Data center cross-connect systems
• Renewable Energy: Solar inverters, wind turbine controllers
• Transportation: EV charging stations, railway signaling

6. Leading Manufacturers and Products

Manufacturer	Headquarters	Representative Products
Phoenix Contact	Germany	PT 10-2.5/HC series (high-current terminals)
TE Connectivity	USA	MiniBoostLatch PCB terminals
Samtec	USA	TMM-101-01-T-S turret board
Weidm ller	Germany	SAM 32 series spring terminals

7. Selection Recommendations

Key considerations include:

• Current/voltage requirements vs. safety margins
• Environmental factors (e.g., humidity, vibration)
• Space constraints (PCB footprint or panel mounting)
• Wire type compatibility (solid vs. stranded)
• Compliance standards (UL 1059, IEC 60947-7)

Example: For outdoor solar inverters, select screw terminals with IP67-rated housings and 600V dielectric strength.

Industry Trend Analysis

Emerging trends include:

• Miniaturization: 1.27mm pitch terminals for IoT devices
• High-speed data integration: Terminal strips with controlled impedance for 10Gbps signals
• Smart terminals: Embedded sensors for predictive maintenance
• Eco-friendly materials: Halogen-free insulators and lead-free plating

The global terminal blocks market is projected to grow at 6.2% CAGR through 2030, driven by industrial IoT and electric vehicle infrastructure demands.