Power technology has always been one of the most important technical areas of electronic components and circuit layer research. Switching power supply technology is the main one in power supply technology. Membrane switches are very popular in terms of the user interface of the application. As a membrane switch manufacturer, HuaiSong Industrial has been following the industry closely. What we share with you next is a good illustration of some of the new developments in switching power supply technology in recent years.
History of membrane switches
In the 1950s, the button switch, toggle switch, and changeover switch were the dominant components. And in the 1960s, the combination switch represented by the key switch appeared. You can use it to complete simple functional transformation. As time went by, the application field of switches keeps expanding and there is an additional whole machine function needed. By the 1970s, keyboard switches with conductive rubber appeared. However, the membrane switch is a new electronic device developed in the late 1970s and early 1980s. As a result, it’s the outcome which meets the needs of miniaturization, digitization, intelligentization and multi-function development of electronic products.
The membrane switch is also known as the light touch keyboard. And raw materials include FPC, PVC, PET, PC, double-sided adhesive tape and others. It is a multi-plane combination of seal electronic plastic products made by screen printing technology. Also, it integrates graphics, keys, punctuation marks, electrical conduction, and electronic switching functions. As we all know, membrane switches are simple and have a wide application.
Standard membrane switch introduction
There are two types of membrane switches: flat membrane switch and membrane keypad. Both of them have graphic overlays, which may have a wide variety of colors. Different colors of key buttons represent their position, shape and size. Usually, we use screen printing for mass production. Also, you can choose the digital printing in the sample production stage to reduce the cost. In the initial phase, we can identify the operation accuracy only by the vision of operators. Because the surface of the membrane switch panel is flat. There is no proper tactile feedback information to show whether the finger is in the effective range of the switch panel to make it work. As a result, it affects users’ confidence in the whole machine monitoring and the speed of operation.
The key button of membrane keypad is slightly raised, and higher than control panels. And the raw material of switch panels can be polycarbonate, polyvinyl chloride, and acrylic. What’s more, the silicone rubber keypad is also widely used. They have better tactile feedback to indicate the action’s effectiveness. As for the circuit layer, HuaiSong Industrial always uses FPCB, PET or printed circuit board. The former two are simple and available for small electricity. PCB membrane switch is more stable, thicker, and available for bigger electricity.
Now, capacitive membrane switches are widely used in electronic components, household appliance and so on. It’s also flat but not use button colors to get the visual effect. These kinds of customized membrane switches often have the touch screen, pressure sensitive adhesives and surface mounted LED to indicate the operation validity. Or even the switch panel can connect loudspeakers to get auditory feedback.
Standard membrane switch design
Button shrapnel on the graphic overlay
For stereo custom membrane switches, they can not only accurately set the range of key button and improve the speed of identification. Also, they make the operator’s sense of touch more sensitive and enhance the decorative effect of user interfaces appearance. During the designing and engineering of graphic overlays, the membrane switch company needs to make arrangements. Equipped with process hole, so that we can get a precise position during die pressing. In general, we use the metal dome, poly dome or other domes to make the embossing key button. As a result, the raised height should be no more than twice the base material thickness. Also, to beautify the user interface of a standard membrane switch, the embossing can vary in many ways.
The modulation ratio of the conductive ink is the main cause of the serious color deviation. And another important reason is that the color requirement for the human-machine interface is too strict. The range of colors is too small. This is difficult to control for any industry. From the point of view of controlling cost, the membrane switch company needs to pay an extremely high expense to reach the small color range. Of course, if the cost increases, then the unit price of custom membrane switches will be higher. For customers, it’s also hard to accept. Thus, we need to set the color within a proper range.
Embossing position and sticker
If the customer wants an embossing graphic overlay, we first need to open mold. Placing key buttons in a suitable position. Otherwise, it will affect the aesthetics of membrane keys. Another mold is also needed for die cutting to shape the overlay. Sometimes, keys connect with the circuit which may use surface mount LED or fiber optic. If they are not in the right position, the switch is not going to work. This principle is not only suitable for customized membrane switches, but also momentary switching.
Another common problem is about the sticker. Besides the raw material selection, we also need to confirm the shape of the prototype. If it has a groove, the membrane switch company needs to choose a better quality mucilage glue. Or if it’s smooth, we only need to select a suitable glue. HuaiSong Industrial is a professional membrane switch supplier in China. And it always keeps updating the membrane switch technology to better satisfy customers’ requirements.