What is the Tactile Switch?

What is the Tactile SWITCH?   

    Generally speaking, a Tactile Switch is a small button-type electronic Switch. Here below introduce the  basic structure, working principle and key features.

1. Basic Structure

A tactile switch is made up of several key parts:

    Button Cap:

    This is the outermost part of the switch, usually made of plastic. It's the part users press directly. Its shape and size vary depending on the design and application. For example, the side buttons on a smartphone are typically small and sleek, making them easy for fingers to operate.So the button cap could be customized the shape in square or round,  material in plastic or silicone. Such as the silicone cap could be waterproof for more ussing areas.

    Metal Dome (Spring):

    This is a crucial part of the tactile switch. When you press the button cap, the metal dome bends, allowing the circuit to connect. It's usually made of materials like copper alloy, which are both conductive and elastic.

    In its natural state, the dome is separated from the contact point, keeping the circuit open.

When pressed, the dome touches the contact point below, closing the circuit.

    Contact Point:

    The contact point is made of metal, often coated with gold or silver. These coatings improve conductivity and resist oxidation, ensuring stable signal transmission. When the dome presses against the contact point, electricity flows through the circuit.    

    Base:

    The base holds and supports all the parts of the switch. It is usually made of insulating materials like plastic. The base’s shape and size determine how the switch looks and how it is mounted.

    Some switches are designed to be mounted on a printed circuit board (PCB).

    Through-Hole: Others use pins that fit into holes on the PCB for a more secure attachment.

2. Working Principle

    From an electrical perspective, a tactile switch works by using mechanical force (pressing the button) to open or close a circuit.

    In its normal state, the metal dome is separated from the contact point, and the circuit is open (no current flows).

    When you press the button cap, the force pushes the metal dome, which bends and touches the contact point, completing the circuit and allowing current to flow.

    Once you release the button, the dome springs back to its original position, breaking the connection and opening the circuit again.

3. Key Features

    Low Operating Force:

    One of the main benefits of a tactile switch is that it requires only a light press to operate. For instance, the volume buttons on a phone can be easily pressed without much effort, making them comfortable for frequent use.

    Long Lifespan:

    Tactile switches are built to last, often enduring tens of thousands or even hundreds of thousands of presses. This is thanks to their sturdy design and durable materials. For example, the tactile switches in a computer keyboard can handle frequent typing over a long period without losing performance.

    Compact Size:

    These switches are small, making them perfect for compact electronic devices. They take up minimal space on a circuit board. For example, in a smartwatch, where every millimeter matters, tactile switches fit perfectly to enable various functions without compromising design.