If you have ever used electronic equipment, you are likely to have encountered surface mount equipment, also known as SMD switches. These miniature components play a vital role in modern electronic products, allowing users to turn on and off devices, adjust settings, and control various functions. However, with so many types of switches on the market, it may be difficult to know which one is suitable for your project.
SMD switches have revolutionized the field of electronic equipment, making them more compact, reliable, and lower production costs than ever before. These micro switches have a variety of applications, including consumer electronics, automobiles, medical equipment, etc. In this guide, we will take a closer look at SMD switches, how they work, and the different types available.
What is an SMD switch?
An SMD switch is a component that allows you to turn on or off a circuit. They are mounted on a printed circuit board (PCB) using surface mount technology (SMT). No through holes are required and greater design flexibility is achieved. SMD switches are usually smaller than through-hole switches, so they are very suitable for compact designs with limited space.
SMT technology allows you to connect components to a circuit board. The process first uses a template to apply solder paste to the surface of the PCB. Solder paste is a mixture of tiny metal balls and flux that helps the solder adhere to the surface. SMD components (such as switches) are placed on the PCB using an automatic placement machine. The components are precisely aligned and positioned, and then they are soldered to the PCB by using a reflow oven to heat the solder paste. The solder melts and flows around the component leading to a strong mechanical and electrical connection.
This automated process can achieve mass production and maintain consistent quality and accuracy. In addition, the use of SMT technology allows components to be placed on both sides of the PCB. Therefore, space utilization and design flexibility are maximized.
How does the SMD switch work?
Most SMD switches usually use small metal levers, plungers, or domes to establish or disconnect the connection between two metal contacts. When the switch is in the ”on” position, a metal rod, plunger, or dome completes the circuit. This allows current to flow through the switch. When the switch is in the ”off” position, the metal rod, plunger, or dome will disconnect the circuit to prevent current from flowing through the switch. For dome switches, the feet of the dome rest on the circuit pad, and when the center collapses onto the circuit pad, the circuit is closed.
Type of SMD switch
There are many different types of SMD switches to choose from, each with its own unique characteristics and applications. The following are some of the most common SMD switch types：
Tactile switch: The tactile switch is a small, thin switch that provides tactile feedback when pressed. Consumer electronics products, such as remote controls and game controllers, have tactile switches. They are usually encapsulated in a housing and have a “click” feeling.
Tactile dome switch: The tactile dome switch is a small ultra-thin switch that provides clear tactile feedback when pressed. They are made of stainless steel and can be soldered directly to the circuit board. They have a long service life and can last for up to 10 million cycles.
Sliding switch: A sliding switch, also known as a DIP switch, is a small switch that can slide back and forth to turn on or off a circuit. Sliding switches are often used in audio equipment and electronic toys.
Push button switch: A push button switch is a long-distance switch, which can be pressed to turn on or off the circuit. Buttons are used in automotive applications (such as door locks and steering wheel controls).
Rotary switch: A rotary switch is a small circular switch that rotates to select a specific function or setting. Rotary switches are used for audio equipment and electronic instruments.
SMD switches Benefits
The advantages of SMD switches are not only in their small size and high reliability. They can also save costs in the manufacturing process. This is because you can use an automatic pick-and-place machine to assemble them onto the PCB. Thereby reducing labor costs and improving production efficiency.
In addition, SMD switches are easier to design into applications due to their minimal space requirements. They also have lower parasitic capacitance and inductance than through-hole switches, thereby improving the performance of high-frequency circuits. Overall, the use of SMD switches can produce electronic equipment with higher quality, more compact structure, and higher production cost efficiency.
Choose the right SMD switch
When choosing an SMD switch, a number of factors need to be considered, including application type, electrical rating, rated life, and switch size. It is very important to choose the switch that suits your specific application to ensure reliable performance.
SMD switches are an important part of modern electronic equipment, providing reliable and compact switching functions. With their small size, thinness, and versatile design, they are ideal solutions for a variety of applications. By understanding the different types of SMD switches and how they work, you can choose the right switch for your specific application and ensure reliable performance. Please contact Shanyo immediately to learn more about our SMD switching solutions.