The **PCB-3-R** is a specific type of **multi-position power terminal block** (often referred to as a "power distribution block" or "bus bar") designed for high-current applications on Printed Circuit Boards (PCBs). Below is a detailed breakdown of its electronic and mechanical specifications. --- ### 1. Key Technical Specifications | Feature | Description | | :--- | :--- | | **Component Type** | High-Current Terminal / Power Tap | | **Mounting Type** | Through-Hole (THT) | | **Material** | Usually Brass or Copper Alloy with Tin Plating | | **Current Rating** | Typically 30A to 60A (depends on PCB trace thickness) | | **Terminal Count** | 6 to 10 pins (varies by manufacturer like Wurth or ERNI) | | **Thread Size** | M3 Internal Thread | --- ### 2. Major Electronic Components & Design The PCB-3-R is not an active component (like a chip) but a **passive mechanical-electronic interface**. Its design focuses on three main areas: #### A. The Threaded Insert (M3) The "3" in the part number usually refers to the **M3 screw thread**. This allows a heavy-gauge wire lug or a bus bar to be screwed directly onto the PCB. This provides a vibration-resistant, high-torque connection that standard headers cannot handle. #### B. Multiple Solder Pins Unlike standard pins, the PCB-3-R features multiple massive solder legs arranged in a circle or rectangle. * **Purpose:** To distribute the high current across a larger surface area of the PCB copper planes. * **Heat Dissipation:** The bulk of the metal acts as a small heat sink for the connection point. #### C. Plating (Tin over Nickel) The part is usually tin-plated. This ensures: * **Solderability:** Easy integration into wave soldering or hand soldering processes. * **Low Contact Resistance:** Minimizes voltage drops across the connection. --- ### 3. Common Applications These parts are found in power electronics where "Board-to-Wire" current demands are high: * **Power Supplies:** Main input/output stages. * **Motor Controllers:** Connecting phase wires to the drive board. * **Automotive Electronics:** 12V/24V distribution blocks. * **Industrial Inverters:** DC link connections. --- ### 4. Implementation Example When designing a footprint for the PCB-3-R, engineers must ensure the PCB through-holes are non-insulated (plated through) to allow the solder to wick up and create a solid mechanical bond. ```cpp // Design Rule Check (DRC) Considerations - Hole Diameter: ~1.5mm - 2.0mm (per pin) - Copper Weight: 2oz or 3oz recommended for high current - Thermal Reliefs: Often omitted to maximize current flow ```