Flexible combination among overlay, dome array and printed or etching circuit board could accomplish complicated electrical function in extremely durable and thin layers
Flexible combination among overlay, dome array and printed or etching circuit board could accomplish complicated electrical function in extremely durable and thin layers.
Membrane switch is defined as "a momentary switch device in which at least one contact is on, or made of, a flexible substrate." by the ASTM (American Society for Testing and Materials). A basic membrane switch structure includes overlay, spacer, printed circuit with tail, and back adhesive. Different layers can be purchased separately or sealed as a turn-key solution depending on the client’s requirements.
As a leading supplier, Joesmen offers advanced membrane switches to several major industrial and medical industries where reliability and quality are the major concerns.
Polydome is formed with polyurethane film by embossing tool. Unlike metal dome, polydome prints conductive silver or graphite ink at the dome’s internal side. It is considered to be cheaper and quieter, but with less positive tactile feedback and fewer life cycles at the same time.
Metal dome is a dome-shape stainless steel sheet normally covered with nickel or gold-plating. It can be different shapes from round to square, with legs or dimples for better assembly and tactile feedback, or with through hole for LED underneath. Metal dome provides actual tactile feedback and longer life cycle.
Overlay is the first layer and interface between you and the machine. The material could be polycarbonate or polyester for various glosses, textures, and hardness finishes. As the raw material is transparent, it can be left without printing for waterproof window or backlight purpose.
Color variety and durability is another important value of choosing overlay instead of SRK. Joesmen has both silkscreen printing and digital printing technology can be adapted for complex and delicate color arrangement. Since the color is printed at the internal side, the printing is protected from end-user and environment damage.
Membrane switch (MS) is an electrical switch with printed circuit. It’s thin and delicate but highly durable and multi-functional. Therefore, it has been widely used in military, medical, industrial, and vehicle products as well as the commercial ones.
With silver and graphite ink printed on PET film, the circuit can be double sides with different layers. The tactile feedback can be from metal dome layer, or to be with non-tactile design as shorting pad. MS design can also fulfill the backlight or shielding request.
MPCB (Printed Circuit Board) is a rigid substrate with laminated etching copper circuit. It can be referred as bare or assembled board with mounted electronic components. The layers can be single or multiple depends on the complexity. Although PCB requires layout design, the manufacturing and assembly can be done automatically for cheaper and faster wiring production.
Bare board quality standard
Flexible Printed Circuit (FPC) is ideal for high current carrying capacity, high temperature and moisture, or small space with large interconnect requirement. Similar as PCB, FPC uses etching copper circuits on soft substrate polyester (PET) or polyimide (PI) for extra thin, light and flexible finish.
FPC has all of PCB’s advantages plus bendable for 3D configuration. The wire routing is repeatable, so the test time can be reduced and error can be eliminated before assembly. Joesmen also provides rigid-flexible combination via tin soldering called hot-bar, conductive paste ACP (anisotropic conductive paste), or RFB (rigid-flex board).