1.attractive appearance&good performance
2.thin&compact&portable
3.low cost&environmental4
4.long service time&heat-resistant

Tactile Switches

The properties and characteristics of different switch varieties vary depending on their application. For example, a switch placed on an outdoor garage door opener must be shielded against variable weather and temperature conditions to a certain degree. An indoor switch, on the other hand, is less likely to be exposed to such hazards and does not require special protection from them. An important innovation in the ongoing development of switch technology was the tactile switch. Simply put, switches are a way to send a signal to an electronic device. When a switch is pressed, it either closes or opens an electrical circuit, which changes the way the connected device operates. Tactile switches distinguish themselves from other switch varieties in that their use involves a sensation that indicates to users whether or not the desired change to the connected circuit was effected by the depression of the switch.

In some cases when a switch is depressed, a circuit connection or breakage is not made. This can be because of inadequate switch depression or for other reasons. A tactile switch indicates to its user that the appropriate action has been performed by providing resistance up to a certain point during its depression. The force required to overcome this resistance is called actuation force. When sufficient force is applied beyond that point, the resistance of the switch is overcome. This variability of actuation force, combined with an audible indication (a feature of many tactile switches), assures users that the intended change to a circuit has been made. Tactile switches are constructed in many shapes and sizes. In most cases, they feature a metal or plastic covering, inner switch equipment, conductive materials and resisting elements like a spring. Some are simply domes, which, when depressed sufficiently, suddenly collapse and then regain their shape when released. Tactile switches come in a wide variety of sizes, shapes, and actuation forces. Using different sizes of metal domes or polydomes will vary the actuation force. Metal domes come in a large assortment of shapes and sizes with actuation forces between 180 to 700 grams; different polydome actuation forces can be achieved by changing the diameter and height of the polydome to meet specific requirements. Tactile switches are available for all kinds of applications and are among the most widely used switch varieties.

Jasper has accumulated many years of membrane switch making experience, and most of our people have been in this business for more than five years. We maintains a work force of highly trained engineers who are able to quickly respond to customers differentiate demands for membrane keypad products. 

Membrane switch has many characteristics, eg light and slim, dust-proof, insulation, anti-shock and easy assemble. By virtue of those features, membrane switch are extensively applied in medical device, industrial control, home electronics, and precise instrument industries etc.  

MEMBRANE SWITCH OPTIONS
There are a number of options within a membrane switch as described below
 
TEXTURING
The graphic overlay is textured in either matt or gloss and a range of custom finishes in between. A matt textured finish is most common. Windows can be printed in the matt polyester to allow clarity for LCD and LED displays and the windows can be tinted in a variety of colors.
 
TACTILE DEVICES
Metal domes are tactile devices that are inserted within the membrane switch to give a physical tactile response when pressed (Clicked). They can be designed as part of the circuit or above the circuit. A range of sizes are available. An alternative to a metal dome is a polyester domes which is created by permanently forming one layer of the membrane into a dome shape.
 
BACKLIGHTING
Backlighting is frequently seen in many devices. There are a number of ways to do this however the most effective are Electro luminescent Backlighting (EL) and woven fibre. Jasper can do EL-embeded membrane switch with perfect combination technique.

RFI SCREENING
Radio Frequency Interference (RFI) is a major factory which industry engineer considered, and also legally restricted in many countries. Electronic equipment must be protected from unanticipated behavior caused by RFI and Jasper Electronics has developed specialist solutions in this area.
 
SURFACE MOUNT DEVICES
It is possible to incorporate surface mounted devices such as LEDs and resistors with the membrane switch. This may save allow costs savings in PCB design while allow flexible placement of the PCB.

Main Specifications:

Materials

1 Polycarbonate, polyester or polyvinyl chloride layers

2 Multi-color graphic overlays

3 Engineered adhesives

4 Metal domes or polydomes

Mechanical characteristics

1 Actuation Force, Nontactile: 4oz. to 16oz.

2 Actuation Force, Tactile: 10oz. to 16oz. TYPICAL

Switch Stack-Up Thickness: available for custom specification

Electrical feature

1 Current Rating: 50 ma AT 30 VDC

2 Actuations, actile: 1 million minimum at maximum rated load

3 Actuations, Nontactile: 5 million minimum at maximum rated load

4 Switch Contact Bounce, Tactile: 10 milliseconds max

5 Switch Contact Bounce, Nontactile: 5 milliseconds max

6 Termination Contact Resistance: 100 ohms max, loop

7 Insulation Resistance: 1 Gohm Win AT 100 VDC

Environmental condition

1 Operation Temperature: -20 °C to 100 °C

2 Storage temperature: -25 °C to 115 °C

3 Humidity: to 95% (switch fully sealed to environment)

Operational Tolerance

Printing tolerance: &plusmn 0.25mm         Cutting/Assemble tolerance: &plusmn 0.2mm