Based on the part number **KMS-D-R**, this refers to a specific series of **Surface Mount (SMT) Side Actuated Tactile Switches**, typically manufactured by C&K (now part of Littelfuse). These are commonly used in mobile devices, wearables, and hearing aids. --- ## 1. Technical Specifications The KMS-D-R is designed for high reliability and compact integration. Below are the primary electrical and mechanical characteristics: | Feature | Specification | | :--- | :--- | | **Switch Type** | Tactile Switch (Momentary) | | **Mounting Type** | Surface Mount (SMT), Gull-wing | | **Actuation Direction** | Side Actuated (Right Angle) | | **Operating Force** | Typically 1.6 N to 4 N (model dependent) | | **Electrical Life** | Up to 100,000 cycles | | **Contact Material** | Silver or Gold plating options | | **IP Rating** | Often IP40 (protected against solids) | --- ## 2. Part Number Breakdown (KMS Series) The nomenclature generally follows this logic: * **KMS**: Series name (Side-actuated SMT switch). * **D**: Solder pad/Body configuration (often denoting the presence of a "ground terminal" or specific physical layout). * **R**: Packaging format (typically stands for **Tape & Reel** for automated pick-and-place assembly). --- ## 3. Key Electronic Components & Materials * **Contact Dome:** A stainless steel dome that provides the "click" feeling (tactile feedback) and bridges the electrical circuit. * **Terminals:** Copper alloy, usually silver-plated for high conductivity and ease of soldering. * **Housing:** High-temperature LCP (Liquid Crystal Polymer) plastic to withstand reflow soldering temperatures. * **Actuator:** A hard plastic plunger that transfers external force to the internal dome. --- ## 4. Common Applications Due to its **side-actuated** nature, this part is ideal for buttons located on the edges of PCBs: 1. **Mobile Phones:** Volume rockers or power buttons. 2. **Medical Devices:** Hearing aids or handheld diagnostic tools. 3. **Consumer Electronics:** Reset buttons on routers or side buttons on smartwatches. 4. **Industrial:** Miniature interface triggers. ---