Memebrane
Switch & Panel
Membrane Switch Graphic Overlay Acrylic Panel
Sheet-Metal
Processing
HF Transformer
Advanced PCB
PCB Assembly

Membrane Switch

A new type of electronic keypad operating system that
integrates key functions, indicator components, and front panels.

The membrane switch is composed of six layers: Graphic overlay, upper-adhesive, the upper circuit, the isolation spacer, the lower circuit and the back adhesive. The contact of the upper circuit is downward, and it is in contact with the point of the lower circuit. The circuit contact bounces back after releasing, then the circuit is disconnected and the loop triggers a signal.

The Membrane switch has strict structure, beautiful appearance and good sealing. It has the characteristics of moisture resistance and long service life. It has been widely used in electronic communication, electronic measuring instruments, industrial control, medical equipment, automotive industry, smart toys, household appliances and other more fields.

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Finger Pressing ( Connected ) Trigger Onetime

Graphic overlay Upper-circuit Spacer Lower circuit

Working Principle of Membrane switch

The basic working principle of the membrane switch is as follows: when the keys is not pressed, the membrane switch is in the normal open state, and its upper and lower contacts are disconnected, and the isolation layer isolates the upper and lower lines; when the keys is pressed, the upper contact point of the circuits is deformed downwards, and it merges with the lower circuit to make the circuit conductive.

The connected circuit signals of the external connection instrument (substrate) to achieve its corresponding function; when the finger is released, the upper circuit that touches the lower point will be bounced back, then the circuit is disconnected, and the loop triggers a signal.

Excellent Waterproof Process ( IP66 )

JRPanel unique waterproof technology with 3M300LSE,
it is able to reach the waterproof grade of IP66 that
can be used in humid environments.

Membrane Switch Application Fields

The membrane switch is consists of keys, front panel, text, marking, logo, transparent windows. And the
design of the graphic overlay can reflect the integration of product function and original color performance,
which is unique. The membrane switches are widely used in intelligent electronic measuring instruments,
medical instruments, computer control, CNC machine tools, communication terminal equipment, various
industrial and household appliances products
(such as copiers, refrigerators, microwave ovens, electric fans, washing machines, electronic game machines, etc.).

Household Appliances
Office Equipment
Instrumentation
Mechanical & Industrial Control
Toys & Remote Control
Silkscreen Printing

Screen printing with exquisite
Patterns and text

Graphic Overlay

Thickness≤1mm
PET/PC Colorless Film

Graphic Overlay

It is generally printed on PET, PC
colorless sheets with beautiful patterns
and text. It has the functions of marking
and keys, and it has the characteristics
of high transparency, high ink adhesion,
high elasticity and high toughness.

Upper Adhesive

It is used to closely connect the panel layer
and the circuit layer to achieve sealing
& connection.It has high viscosity and anti-aging
Thickness of 0.02 ~ 0.05mm

Upper Circuit

This layer is mainly metal dome or die-
pressing silver paste point, which as the upper
circuit. It can be contacted with the lower
circuit by pressing the key to get connected

The Spacer

It is mainly used to insulate the upper &
lower circuit layers and bond them togetterh,
it also can prevent the metal dome from shifting.
Generally use PET double-sided tape,
its thickness is 0.05-0.2MM, etc.

Lower Circuit

The main circuit layer, this layer uses PET,
It use silver paste and carbon ink to
print the circuit design, which has excellent
conductive properties, also can mount LED.

Back Adhesive

Membrane switch back adhesive,
It is used for assembly bonding with
instruments & equipment.
JRPanel use genuine 3M adhesive,
Various types are available:
3M55236, 3M9448A
3M467, 3M468, 3M300LSE

Membrane Switch Technical Parameters:
Electrical
Properties
Operating Voltage Working current Contact resistance Insulation resistance Base Material Voltage Rebound time Insulation ink withstand voltage
<25VDC ≤50mA 20~150Ω
According to cable length
≥100MΩ (100VDC) 1.5kDVC ≤6ms 100VDC
Mechanical
Properties
Reliability Life Key Displacement Force Silver Trace Width Contact Pitch
>1 million times 0.1~0.2mm
(Non-Tactile)
0.3~0.8mm
(Embossed key)
180~350g ≥0.3mm
min. spacing 0.5mm
With green Insulating oil
2.54mm(common)
1.0mm(common)
1.27mm
Environment
Properties
Operating Temperature Storage Temperature Atmospheric Pressure  
-20℃ ~ +80℃ -30℃ ~ +85℃
Humidity 95%±5%
86~106KPa /
Printing
Index
Printing Size Deviation Hallow Deviation Color difference Others
±0.20mm
Unclear edge deviation ±0.2mm
± 0.1mm/100mm According to the Pantone card,
with 10%
No ink scattered, no handwriting
No creases or removal
Transparent window is
transparent and clean,
No scratches, holes, impurities
The Comparison of PVC/PC/ PET
PVC - Not supply PC(Polycarbonate) PET(Polyester)
Non-degradable (not environmentally) Degradable ( Environmentally ) Degradable ( Environmentally )
Glossy / Transparent to opaque
/ Good light transmittance
Glossy / Transparent to opaque / Good light transmittance Glossy / Transparent/ Good light transmittance
-10~60℃ -30~110℃ -20~120℃
Thickness:0.175~0.5mm Thickness:0.175~1.0mm Thickness:0.125~0.2mm
It is stable to acids, alkalis and salts at room temperature. Good abrasion resistance, flame-retardant, self-extinguishing, noise reduction and shock absorption, and good electrical insulation. Poor thermal stability. 70% light transmittance, suitable for less demanding display panels, not suitable for button panels, because the texture is particularly soft, the buttons are easy to be broken by long-term use, the life is not long, and they are not resistant to aging, The material can not be degraded, not environmentally, can not withstand high temperature, It can be use at room temperature within 65 degrees. Low water absorption, good dimensional stability, excellent bending, tensile and compressive strength, excellent heat resistance, cold resistance, electrical insulation and atmospheric aging resistance; Poor chemical resistance, poor fatigue resistance, prone to stress cracking. The general scope of application is the most extensive, except that it can meet the requirements of most membrane switch panels, Among them, the high light transmittance of glossy PC can meet the requirements of liquid crystal display windows PC matte, material, light transmittance 78%, material is softer than PET, can be bent at will, is not resistant to aging, can withstand weak acids and alkalis, and is also one of the most widely used materials on the market at this stage. (F150 is small matte), the emboseed feeling weaker than PET, the material is environmentally friendly and degradable, and it can meet export standards. Good chemical resistance, insoluble in common organic solvents, not resistant to alkali. It has excellent mechanical properties, electrical properties, rigidity, hardness and maximum toughness of thermoplastics, low water absorption, excellent wear resistance and friction resistance, and high dimensional stability. The tensile strength is comparable to aluminum film, which is much higher than PC and PVC. F150 is imported PET frosted material with high temperature resistance and aging resistance. Even if it is frosted, the light transmittance of the material is still very high. The light transmittance of PET is 89%, making the color more vivid. It is the most ideal substrate for making membrane switch circuits. It is suitable for products with high environmental requirements or products with digital tubes.

Material used in the
circuit layer

The base material of the circuit should be polyester
(polyethylene phthalate) Film (Potyester referred to as PET).
It has good insulation and heat resistance, high mechanical
strength, transparency and airtightness, especially folding
resistance and high elasticity.

The thickness of
the plastic

The thickness of the plastic substrate is 0.25mm or below and is called a film. It is mainly used as the panel layer of the membrane switch. Various indicative patterns and text are printed on the back to indicate the operation area of the corresponding key switch. Depending on the size of the button, the material is thick, the touch force is increased, and the response is slow; the material is too thin, the feel is poor when touched, and the rebound is not obvious. Thickness above 0.25mm is called plate, which is not suitable for three- dimensional key forming. It can be used as an indicative sign panel in the keyless operation area, and can also be used as a lining for membrane switches to increase its hardness.

EMBOSSED KEY TYPE:

JRPanel can provide various types of embossed-key as following picture.
The default is circle-embossed (the left 1st ). If you need other types, you can specify it in the remarks or drawings when placing an order.
Inspection & Check

Membrane switch & Graphic overlay

1. Check the color: The contrast of colors. Due to ambient light and other reasons, it can not be directly compared with the real sample or computer pictures. It needs to be checked with the Pantone color card. The general colors can only be closer, couldn't be same. JRPanel uses Pantone Formula Guide Coated card. [Finding color numbers on https://www.pantone.com/color-finder]

2. Shape inspection: Check the shape and internal slots and windows accordingly according to the product design drawings.

3. Appearance inspection: check the graphics of the panel layer,the logo text, etc, whether there are defects, omissions, stains, etc. Whether the window and press position are offset. If there is protective film attached to the window.

4. Check the peel strength of the adhesive: check whether the adhesive is the adhesive selected according to the order, and test the peel strength of the adhesive is not less than N/25mm.

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