A tactile metal dome, also known as a snap dome, is a normally open momentary contact that provides a crisp tactile feel, letting the user know the button was pressed. Metal domes offer many key advantages over other switch solutions. Low profiles and high life cycle ratings make tactile metal domes a reliable choice. With a large variety of dome shapes and styles, determining the right metal dome for your application is crucial. Engineers must consider the different benefits of various tactile metal dome switches to achieve the desired user experience.
Selecting the Right Tactile Metal Dome for Your Application
There are five main types of tactile metal domes: four-legged, round, triangle, oblong, and SMT. You can customize most domes to meet your end product’s force, height, audibility, or tactile feedback requirements. Features to consider adding to your domes include backlighting, built-in actuation, over-travel, and many more.
| Metal Dome Styles | Benefits | Circuit Boards |
| Four-Legged | – Crisp tactile feedback – High actuation forces – Very customizable | – Single-sided circuits – Double-sided circuit – Flex circuits |
| Round | – Soft tactile feedback – Low profile | – Double-sided circuits |
| Triangle | – Crisp tactile feedback – High actuation forces relative to their size – Ideal for limited circuit board space | – Single-sided circuits – Double-sided circuit – Flex circuits |
| Oblong | – Low profile – Long narrow spaces – Full-hand squeeze applications | – Double-sided circuits |
| SMT | – Solderable – Integrates into SMT equipment – Loaded into Tape and Reel | -Single-sided circuits -Flex circuits |
Four-Legged Metal Domes
First, four-legged domes, one of the most commonly used dome switches, adhere to a wide variety of surfaces, including single—or double-sided circuit boards, flex circuits, or membrane switch panels. They can achieve high actuation forces and tactile feedback relative to their size. Four-legged domes are easy to customize to your unique specifications.
Round Metal Domes
Round or circular metal domes are ideal for applications that require a low-profile switch with a soft tactile feel. Their round design makes them suitable for applications that require a double-sided circuit board with a membrane overlay.
Triangle Metal Domes
Next, triangle tactile metal domes, also known as three-leg domes, can achieve high actuation forces despite their relatively small size. Therefore, their shape makes triangle domes ideal for applications with limited or narrow available circuit board space.
Oblong Metal Domes
Oblong or oval-shaped metal dome designs are ideal for long narrow spaces or applications where a full hand squeeze is preferable to a single finger press. Because of this, they typically have a soft tactile feel.
SMT Metal Domes
Finally, surface-mount technology, SMD domes, or solder domes, are just like standard four-leg domes but with two tabs for soldering. SMD domes are mounted directly to the circuit without impacting performance. The SMD tactile dome is loaded in tape and reel for use in your SMT or pick-n-place machines and adhered to the circuit with reflow soldering.
In conclusion, the interface between the user and the product is vital to your design. Tactile feedback is just one of the many elements you can control. Snaptron can work with you to ensure that you select the right tactile metal dome switch for your application. So, get started today by downloading our technical design guide for metal dome switches.
