May 15, 20232724
Switches are components that control the circuits in modern times. You can see them everywhere. All kinds of switches work in equipment such as electric lights, microwave ovens, and large machines. Everything improves in daily life, so various types of advanced switches appear. Let's take a look at the development history of membrane switches.
Toggle switches are popular in the 1950s. They are manually controlled switches mainly used for AC and DC power circuit. There are benefits, such as small size and easy operation. Those switches were common in electronic equipment.
Toggle switches cut off or connect the circuit by toggling the contacts of the plastic handle. The components are mainly used in low-voltage circuit. It is characterized by multiple functions, fast response speed, and strong resistance to electricity, light, and magnetic interference. You can see them in various instruments and instrumentation equipment, electric toys, audio equipment, and medical equipment.
There are also transfer switches. This is a kind of switch that applies to two or more power supply or load conversion. The switch is composed of contact system, positioning system, handle and other components. It is characterized by small installation area, simple and compact structure, safe and reliable operation. You can see them in circuit control and electrical equipment, etc.
In the late 1970s, membrane switches came out. They are much better than previous ones. Membrane switch, also known as light-touch keyboard, is composed of FPC, PVC, PET, PC, double-sided adhesive and other materials. It is a multi-plane combined and sealed set of graphics, buttons, punctuation marks. It is a plastic electronic product that integrates conduction and electronic switching functions. That's why they are widely used.
With the development of electronic technology, more and more new products come into use. The structure is the graphic overlay, the rubber pad layer, the upper and lower layers and the sandwich layer of the control circuit. The function is the same as the key switch. There are different types of membrane switches. Different industries have their own exclusive products.
In short, membrane switches are evolving. There will be the diversification of the market in the future.
Flexible Membrane Switch
Flexible membrane switch is a typical type of membrane switch. Why is it called "flexible"? The mask layer, isolation layer, and circuit layer of the component are all composed of various soft films with different properties.
The circuit layer of the flexible membrane switch uses polyester film (PET) with good electrical properties as the carrier of the switch circuit pattern. This layer is also divided into hand-feeling shrapnel and upper and lower circuits. Due to the properties of the polyester film, the membrane switch is with good insulation, heat resistance, bending resistance and high resilience.
The graphics of the switch circuit, including the connection of the switch and lead-out wires, are all printed with low-resistance conductive paint cured under low-temperature conditions. Therefore, the composition of the entire membrane switch has a certain degree of flexibility, which is not only suitable for use on a flat body, but also fits with a curved surface body.
The lead wire of the flexible membrane switch is integrated with the switch body itself. When making the connection of the group switch, it is gathered at a certain place on the film, and extends outward according to the position specified by the design and the standard line distance, as a soft membrane switch. Arbitrarily bendable and sealed lead wires are connected to the rear circuit of the whole machine.
Rigid Membrane Switch
The graphics and circuits of the rigid membrane switch are made on common printed circuit copper clad laminates. It is characterized by convenient materials, stable process, low resistance, and some elements in the circuit can be directly welded on its back. In the case of a small size, the hard lining layer can be omitted. Rigid membrane switches generally use metal guides as the conduction labyrinth contacts, so they have a better hand feel.
The disadvantage is that it is not as convenient to assemble in the whole machine as the flexible membrane switch. It is often necessary to weld the plug-in and make the lead out through a flat cable. For the information feedback of the rigid membrane switch, besides the buzzer signal and LED indication, the metal feel shrapnel can generally be used.
Planar Membrane Switch
The planar membrane switch can only be recognized the accuracy of the operation by the operator's vision. There is no appropriate feedback information to indicate whether the finger is pressed in the effective range of the switch to make the switch operate, thus affecting the confidence in the monitoring of the whole machine and the speed of operation.
Raised Button Membrane Switch
Raised button membrane switch is a kind of thing that makes the switch key body slightly raised, higher than the panel. It owns three-dimensional shape. The key can not only accurately define the range of the key body, improve the recognition speed, make the operator's sense of touch more sensitive, but also enhance the decorative effect of the product appearance.
The production of the three-dimensional key must be done in the design stage. It equips with process holes, in order to have accurate positioning when the mold is pressed. The height of the three-dimensional protrusions should generally not exceed twice the thickness of the substrate. In order to beautify the appearance of the product, the protrusion of the raised membrane switch can be made in many ways. It must be arranged in the design stage of the panel, and a process hole is provided for precise positioning when the mold is pressed.
The height of three-dimensional convex should generally not exceed twice the thickness of the substrate. For the aesthetic appearance of the product, the protrusion of the raised membrane switch can be varied in many ways.