In the realm of tactile switches, the key dome stands as a linchpin, seamlessly directing the flow of power. At its core, the primary role of this ingenious component is to facilitate the interruption and conduction of electric current, making it a pivotal element in various electronic devices.

Exploring the Key Dome’s Role

Nestled upon the conductive segment of the PCB, typically positioned just above the circuit board’s golden fingers, the key dome plays a pivotal role. When a user exerts pressure by pressing down on it, the key dome responds by depressing at its center point. This simple yet ingenious action establishes contact with the PCB’s traces, effectively completing an electric circuit. This connection allows the electric current to flow freely, thus ensuring the smooth and precise operation of the entire device.

The Role of Material

The material used in crafting the key dome is of paramount importance. Stainless steel is a common choice due to its durability and conductive properties. Typically, stainless steel key domes boast a hardness rating ranging from 350 to 550 HV (Vickers Hardness). These key domes undergo a meticulous manufacturing process, involving mold stamping and essential cleaning procedures, ultimately transforming them into finished components.

Unlocking Surface Treatment

However, the surface of the key dome often presents a challenge. In its raw state, stainless steel exhibits irregular patterns on its surface. Unfortunately, this surface irregularity can lead to unstable electrical resistance when electric current flows through it, resulting in higher resistance values than desired.

To combat this issue and achieve stable electrical resistance with lower values, specialized surface treatments come into play. Among the most common methods are nickel plating and silver plating. These treatments offer a solution by rendering the surface more uniform and predictable. The result? Resistance levels that can be precisely controlled within the desired range of ohms, ensuring the device operates as intended.


In the intricate world of tactile switches, the key dome is a silent hero, enabling the seamless flow of electric current and ensuring the flawless functionality of our electronic devices. With the right material and meticulous surface treatment, these unassuming components play a crucial role in creating a dependable and efficient user experience. Understanding the significance of the key dome sheds light on the meticulous craftsmanship that goes into even the smallest components of our electronic marvels.

Tactile Switches
Tactile Switches