Littelfuse Launches First Reflow-Compatible Illuminated Tactile Switch with Long Travel and SPDT Function

­Littelfuse, Inc. announced the expansion of its K5V Series illuminated Tactile Switch family with the release of new K5V4 models. These include Gull Wing (GH) and 2.1 mm Pin-in-Paste (PIP) versions that are reflow soldering-compatible. 

Built using a high-temperature PAR (polyarylate) material with a 250°C thermal deformation threshold, the new K5V4 switches are ideally suited for manufacturers transitioning from wave to reflow soldering processes. By eliminating the need for silicone sleeves or special handling and enabling direct SMT assembly for the first time, they reduce production costs, support increased throughput, and improve end-product quality - all while maintaining durability and tactile performance.

“These new K5V4 switches are designed to meet the demands of today’s dense electronic systems, where space efficiency, reliability, and user interface feedback are critical,” said Jeremy Hebras, VP, Switches & Sensors Engineering at Littelfuse. “The K5V switch product series has been created to answer unique customer device architectures where the main board and components are positioned at a 90° angle to the front panel. In combination with long travel, sharp tactile feel, and backlighting, the K5V is ideal when accurate device control is needed—especially where unwanted actuation or lack of immediate user feedback is not acceptable.”

Key Features and Benefits

• Reflow soldering-compatible via PAR material—no sleeve required
• SPDT contact configuration with normally open and normally closed options
• Sharp tactile response with audible click and 4N operating force
• Integrated high-brightness LEDs in multiple color and bi-color options
• Compact, dust-resistant design for reliable operation in dense boards
• Gold-plated dome contacts for superior long-term contact performance
• Available in SMT (GH) and THT (PIP) versions for design flexibility

Markets & Application

• Data centers and servers: System control and diagnostic interface buttons
• Network infrastructure: Reset and feedback switches for routers and telecom devices
• Industrial equipment: Control panel interfaces, safety reset points, and signal input
• Pro audio/video systems: Tactile response for mixers, switchboards, and low-light interfaces

By delivering the first long-travel, SPDT, illuminated tactile switch in a reflow-capable SMT package, Littelfuse fills a critical gap in the market. Competing solutions typically require wave soldering, adding complexity and cost to the assembly process. The K5V4 Series brings together superior ergonomics, visual feedback, and manufacturability in one compact, robust solution.

This expansion reinforces Littelfuse’s commitment to advancing tactile switch technology and supporting OEMs with high-performance human-machine interface (HMI) components optimized for modern production environments.

Availability

The K5V Tactile Switches are available in tape and reel format, with quantities ranging from 1,000 to 2,000 units.

For More Information 
Additional information is available on the K5V Tactile Switch product page.