Introduction and Application
Membrane switch, also known as touch button, is an electronic switch that integrates panel and switch functions.
membrane switch
Thin film circuit
silver circuit
Nickel sign
film panel
touch button
touch switch
FPC membrane switch
LED buttons
EL Backlit Membrane Key Switches
dome key switch
switch panel
Instrument switch button
Medical Control Silicone Key Switch
Easy to install (easy to assemble)
Flexible design – the design can be customized to meet the needs of different applications
Scope of application
household appliances
medical instruments
Industrial equipment
Computer Peripherals
military industry
2. Production capacity
General Membrane Switch
Ordinary flat membrane switch includes upper and lower lines, insulation isolation layer, and optional graphic printing on the panel
When the panel and the upper circuit are under pressure, the upper circuit will pass through the isolation layer and contact the lower circuit, and the electronic contact (signal) will be generated.
Design according to the needs of different applications
PET key membrane switch
The raised button type includes embossing the upper line button points to enhance the feel. The rest includes isolation layer, lower circuit and optional panel printing
The principle is the same as the ordinary type. When the panel button point and the raised part of the upper circuit are in contact with the lower circuit, the electronic contact (signal) will be generated.
Although the PET convex key is limited by the operation and storage environment, the convex key can basically be adjusted to different strength requirements.
Metal Dome Membrane Switch
The installation/placement of metal shrapnel under the keys not only enhances the tactile sensation but also plays a conductive role.
The pressure acts on the key points of the panel, and also acts on the metal shrapnel, and conducts the circuit through the metal shrapnel
It provides stable and consistent electrical and mechanical operation
Cold Light/LED, Metal Dome Membrane Switch
Use cold light as the backlight source of the panel
Since the EL light-emitting layer is extremely thin, the influence on the thickness of the entire set of membrane switches is very small
3. Product Specifications
Mechanical behavior
Maximum working voltage 30V(DC)
Maximum operating current 100mA
Contact resistance 10Ω-500Ω
Insulation resistance 100m(at250V)
Withstand voltage 250Vrms (50-60Hz)
Contact jitter time <5ms
Operating temperature -25°C-+60°C
Allowable humidity 95%
Different characteristics of different products
General Membrane Switch
Button strength: 4-16oz.
Key stroke: .005-.010
Service life**: more than 5 million times
ET key membrane switch
Key strength: 8-24oz.
Key stroke: .020-.030
Service life**: more than one million times
Metal Dome Membrane Switch
Key strength: 9-14oz.
Key travel: .020
Service life**: more than one million times
Cold Light/LED, Metal Dome Membrane Switch
Button strength: 10-15oz.
Key travel: .020
Service life**: more than one million times
**Structural design and different materials will directly affect the service life
:::Substrate of membrane switch
Polycarbonate Film
PC is a thermoplastic film widely used in membrane switches
Available in different film thicknesses and textures, especially for panels and membrane switches with transparent windows
Advantages have excellent light transmittance
Variety of film thickness options
Multiple finish/texture options
easy to handle/process
Strong flame retardancy
Wear-resistant
Excellent heat resistance
Polyester film
Due to its excellent temperature resistance and insulating properties, polyester film is regarded as the material of choice for the printed circuit part of membrane switches, especially for panels used in high-demand devices
advantage
Outstanding chemical resistance
high softness
high transparency
Highly insulated
Dimensionally stable
Significant tear resistance
Wear-resistant
Excellent convex effect
:::General physical property table
Characteristic Unit Test Methods Polycarbonate Polyester
Density g/cm3ASTMD15051.201.40
Moisture transfer g/in2/24hrsASTMF3720.01380.0023
Insulation KV/milASTMD1492.203.00
Light transmittance%ASTMD10030.801.50
Flame resistance–U.L.Bulletin94VTM-2minNotrated
:::Membrane switch adhesive
Bonding for inner layers of membrane switches
Acrylic adhesive has various functions such as anti-peeling, anti-position shift, etc.
Considerations
Elements of Choosing the Appropriate Adhesive Paper
The complexity of panel design, including the number of buttons, their location and their appearance.
Key press type of the panel
Key structure (flat type, convex key type)
The area of adhesive tape involved in the key area of the part and the surrounding area
Operating and Storage Environment
:::Printing of panels
type of promotion
Button raised type
Molds are machined in specific places to create 3D shapes
Provide vertical convex key type keys as the contact layer to improve the feel, and avoid contact with the circuit layer and the configured LED (Light Emitting Diode)
Increase the free space in the key area to enhance key function
Make the finished product look better
texture
Screen printing process can be locally printed at the desired location to vary the matte/smoothness
Protect panels against chemicals
Enhance the transmittance of LED lights
Improve wear resistance
To achieve special printing effects.
The protective layer
Another silkscreen process – the first glossy layer is printed in localized locations
Enhance the transparency of the display window
Improve wear resistance
Reduce the scorching degree of the light-emitting position, soften the output light
Protect panels from chemicals
transparent window
Panels made from highly transparent film so that the desired location can be used as a see-through window
:::Other technical requirements
film opening protection
Different methods depend on different application devices
Anti-static protection
Conductive Silver/Carbon Lattice
Conductive film
Metal or metal surface treatment film layers
Selection of protective materials/methods
product operating environment
proper grounding
Number and size of displays/transmissive parts
Is there a high frequency/AC alternating current power supply such as cold light sheet
Post time: Jul-13-2022