Tactile Switches

Tactile switches are electronic components designed to provide a distinct, momentary electrical contact accompanied by a discernible "click" sensation. This haptic feedback is critical for user interface applications, confirming actuation and enhancing operational precision in a wide array of devices.

These versatile switches are engineered to accommodate various mounting configurations and environmental demands. From PCB tactile switches designed for direct integration onto circuit boards to robust tactile push button switches for panel mounting, or compact micro tactile switches for miniaturised assemblies, selecting the appropriate tactile button ensures reliable input and a positive user experience in diverse professional and industrial settings.

How Tactile Switches Work

A tactile switch operates via a small metal dome that collapses when pressed, completing an electrical circuit. This mechanism provides a clear “click” to indicate successful actuation. Once released, the dome springs back, breaking the circuit.

In a PCB switch or SMD switch setup, the tactile switch is mounted directly to the board. The compact form factor and reliable contact make it ideal for dense layouts and high-use applications. The tactile feedback improves usability while reducing accidental activations.

Industrial Applications of Tactile Switches

Tactile switches are widely used in industrial systems that require precise and reliable user input. Key applications include:

• Control panels: Start/stop buttons, mode selectors, and emergency stop inputs rely on tactile push button switches for clear feedback in harsh environments.
• Test and measurement equipment: Oscilloscopes and multimeters use PCB tactile switches for accurate function selection and menu control.
• Medical devices: Non-critical instruments, such as diagnostic or monitoring equipment, benefit from micro tactile switch components that are compact and responsive.
• Automotive controls: Dashboard functions, steering wheel buttons, and infotainment systems depend on tactile buttons to perform reliably despite vibration.
• Security systems: Keypads and access panels use circuit board switch components for reliable code entry and status confirmation.
• Telecom equipment: Routers, switches, and network panels integrate SMD tactile switches for reset and config buttons in space-constrained designs.

What are the Different Types of Tactile Switches?

Tactile switches come in various forms and mounting styles, each suited for different application requirements and design constraints.

• PCB tactile switch: Designed for direct mounting on printed circuit boards. Available in both through-hole and SMD switch formats.
• SMD tactile switch: Optimised for surface mounting via pick-and-place machines. Ideal for compact consumer electronics.
• Micro tactile switch: Very small form factor for limited-space applications like wearables and portable instruments.
• Tactile push button switch: Includes a larger actuator or cap, ideal for finger-friendly interaction or panel mounting.
• Circuit board switch: A general category including tactile, DIP, and other switches mounted to PCBs. Tactile buttons stand out for their click feedback and ease of use.
• PCB button: A term often used interchangeably with tactile switch, referring to the physical actuation point in an embedded design.

These types vary in dimensions, actuation force, travel distance, and expected lifespan (number of cycles), allowing engineers to select the most appropriate tactile switch for the specific demands of their application.

Tactile Switch Installation

Installing a tactile switch primarily involves securely mounting it onto a Printed Circuit Board (PCB) or a control panel and establishing the necessary electrical connections. The specific steps will depend on the switch's mounting type.

1. Preparation

Ensure your PCB is clean and properly prepared for soldering. For through-hole PCB tactile switches, ensure the holes are clear. For SMD tactile switches, verify that the solder pads are free of contaminants.

2. Mounting

Through-Hole Mounting

Insert the pins of the tactile switch through the corresponding holes on the PCB. Ensure the switch is oriented correctly, especially if it has a specific alignment key or a preferred direction for actuation.

Surface Mount Device (SMD) Mounting

For an SMD switch, carefully place the component onto its designated solder pads on the PCB. This often requires precision placement, especially for micro tactile switches, and is commonly done using automated pick-and-place machines in manufacturing.

Panel Mounting

If you are using a tactile push button switch designed for panel mounting, carefully cut the appropriate sized hole in your panel. Insert the switch and secure it using any provided nuts, washers, or snap-in features.

3. Soldering

**Through-Hole **

Solder each pin to its corresponding pad on the underside of the PCB, ensuring good solder joint formation that is shiny and covers the pad and pin securely.

SMD

Solder the terminals of the SMD tactile switch to the PCB pads. This is often done using reflow soldering processes in large-scale manufacturing, but can be done manually with a fine-tip soldering iron for prototyping or repair.

4. Wiring (if applicable)

For panel-mounted tactile buttons that aren't directly soldered onto a PCB, connect the appropriate wires to the switch terminals. Ensure correct polarity and secure connections to avoid intermittent operation.

5. Testing

After installation, it’s crucial to test the circuit board switch for proper functionality. This involves applying power to the circuit and actuating the switch to verify that it provides the expected electrical contact and tactile feedback. Check for any short circuits or open circuits using a multimeter if issues arise.

Proper installation ensures the longevity and reliable operation of the tactile switch within its intended application.

How to Choose the Right Tactile Switch

Selecting the optimal tactile switch for your application involves considering several key parameters beyond just the "click" sensation.

Mounting Type

Decide whether you need a PCB tactile switch (through-hole or SMD tactile switch) for direct board integration or a panel-mount tactile push button switch for user interfaces.

Dimensions and Footprint

For small designs, use a micro tactile or small SMD switch. Verify dimensions and pinout for PCB compatibility.

Actuation Force

Actuation force is the pressure needed to activate a tactile button, measured in grams-force (gf) or Newtons (N). Choose a force balancing user comfort and preventing accidental presses.

Travel

The actuator's travel distance from its resting position to the point of contact affects the switch's tactile feedback.

Lifespan (Operating Cycles)

Consider the expected number of actuations the switch will endure. High-reliability applications, like industrial control panels, demand switches rated for millions of cycles.

Contact Rating (Voltage/Current)

While tactile switches are generally low-power, ensure the switch's electrical ratings meet or exceed the requirements of your control circuit.

Environmental Sealing

For dusty, moist, or chemically harsh environments, choose switches with suitable IP ratings for durability and reliable operation.

Operating Temperature Range

Verify that the switch can perform reliably within the minimum and maximum temperatures of your operating environment.

Terminal Type

Decide on the terminal configuration (e.g., J-lead, gull-wing for SMD; straight, bent for through-hole) based on your soldering process and PCB design.

By carefully evaluating these specifications, you can select the most suitable tactile switch that ensures both functional performance and long-term reliability for your electronic design.

Ordering and Getting Tactile Switches Delivered from RS Australia

At RS Australia, we pride ourselves on supplying a comprehensive selection of high-quality tactile switches for electronic and industrial uses from top brands like C & K, Panasonic, and TE Connectivity.

In addition to tactile switches, discover our extensive inventory of industrial equipment, such as mini power connectors, circuit board switches, and even display development tools, all readily available for online purchase.

We offer fast, nationwide shipping for both individual and large-volume orders of your preferred PCB tactile switch or tactile push button switch. More information regarding our delivery options can be found on our delivery page.