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Introduction to the use of membrane switches

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微信图片_20220518171255
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 SwitchFPC membrane switch  (1)

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