Product Announcement from Esterline Interface Technologies
Membrane switches are a versatile, low cost and reliable technology. Combining layers of polyester (PET) and acrylic based adhesives with screen printable conductive circuits and graphic overlays, membrane switches offer developers of Human Machine Interface systems an alternative to bulky mechanical switches – and they are thin, environmentally robust, and assembly-friendly.
Tactile feedback in a membrane switch is actually an enhancement, which provides the user feedback when they press the key location. Typically, the switch consists of a top and bottom layer of polyester with a tactile actuator that when pressed, momentarily completes the circuit while providing the user a degree of response based on the switches construction.
- Posi-Tac II: This construction performs well in situations where abuse, harsh environmental conditions and errant electrical charges are inherent.
- Poly-Tac II: A hybrid switch construction providing tactile response through a custom embossed overlay. Cost-effective in applications with highly populated key arrays or in smaller keypads with significant volume requirements.
- Uni-Tac: A highly cost-effective and proven construction, but with limited tactile application opportunities.
- Poly-Tac I: A popular and sometimes cost-effective alternative to stainless steel dome construction.
- PushGate®: A unique pushbutton switch that combines the advantages of discrete mechanical and flat panel membrane switches with a host of other benefits, making it ideal for next-generation products.
Non-tactile membrane switches rely on a sensory response other then tactile touch, such as an audio or visual stimuli that alerts the user to switch closure.
Non-Tactile Switches perform well in abusive environments and are more conducive in applications where large, hidden or irregular shaped keys are a requirement.
- Traditional Non-Tactile: This construction performs well in situations where abuse, harsh environmental conditions and errant electrical charges are inherent.
- Uni-Layer: A hybrid switch construction providing tactile response through a custom embossed overlay. Cost-effective in applications with highly populated key arrays or in smaller keypads with significant volume requirements.
Printed circuit board switches are utilized in two situations: 1) where there are trace routing limitations with traditional membrane switches, or 2) the OEM customer would like to utilize the PCB as a ridged backer that can also be populated with active and passive components, reducing the amount of materials and interconnects.
- Non-Tactile: A PCB integrated construction offers efficient design for most Non-Tactile keypad programs, regardless of the key density. In addition to offering more trace routing capability the PCB can incorporate passive and active components, plus act as a rigid backer.
- Tactile: Like Non-Tactile, a PCB integrated construction offers an efficient design for most Tactile keypad programs, regardless of the key density. However, the Tactile construction also provides lower electrical resistance – in addition to offering the more trace routing capability, incorporation of passive and active components, plus acting as a rigid backer.
PushGate® us a unique pushbutton switch that combines the advantages of discrete mechanical and flat panel PCB backed membrane switches with a host of other benefits, making it ideal for next-generation products.
The thin profile PushGate pushbuttons are cost-effective and simple in design. Its superior reliability makes PushGate one of the leading switch technologies in the world. Successful actuations and a crisp, consistent tactile feel do not degrade over time – even after half a billion actuations – differentiating it substantially from conventional mechanical and membrane switches.
Crisp, Consistent Tactile Feel
- Superior tactile feel does not degrade over time or use
- Set your product apart from the competition by giving your keypad a high quality feel.
Durability and Reliability
- 30,000,000 plus actuations
- Ideal replacement for tac or metal dome switches • Impossible to "tease"; (Click=Closure)
- No bending or flexing parts to fail
- -40° to +85°C operating and storage temperatures
SPECIFICATIONS AND SELECTION GUIDE
- Membrane Electrical
- Operating voltage: 30 volts DC*
- Operating current: 30 milliamps* (*recommended maximums into a resistive load)
- Resistance with graphite: 200 to 500 ohms
- Operating circuit resistance for circuit boards: <100 ohms
- Operating circuit resistance for elastomer assemblies:
- <100 ohms with silver shorting pads
- <200 to 300 ohms with carbon pills
- Contact resistance: <10 ohms
- Circuit resistance: <100 ohms (ohms depends on size/configuration of circuits)
- Contact configuration, normally open momentary contact: SPST (DPST available non-tactile)
- Contact bounce: <10 milliseconds with stainless steel domes
- Membrane Mechanical:
- Life expectancy Tactile: 2,000,000 cycle
- Life expectancy Polydome: 1,000,000 cycles
- Life expectancy Non-Tactile: 5,0000,000 cycles
- Actuation force, Tactile, typical range: 15 oz. ± 3 oz.
- Actuation force, Non-Tactile, typical range: 9 oz. ± 3 oz.
- Membrane Environmental:
- Operating temperature, normal range: -20º to 70ºC
- Storage temperature, normal range: -40º to 85ºC
- Relative humidity: 0 to 95% non-condensing
- Membrane Durability:
- Dielectric strength: 1,200V per mil of U.V. curable printed dielectric
- Polyester: 2,600 to 3,100V per mil (2850 avg. per mil)
- Polycarbonate: 1,500 to 1,700V per mil (1,600 avg. per mil)
- Polyester abrasion resistance: slight polishing, very little scratching
- Polycarbonate abrasion resistance: moderate scratching
- PushGate Electrical:
- Voltage, membrane: 3-30 VDC or AC peak
- Voltage, PCB: 3-50 VDC or AC peak (higher available)
- Current, membrane: 20mA (higher contact rating available)
- Current, PCB: 50mA (higher contact rating available)
- Power, membrane: 0.6 watts (higher contact rating available)
- Power, PCB: 1.0 watts PCB (higher contact rating available)
- Switch resistance: <2 ohms
- Contact configuration, normally open or closed: SPST, SPDT, DPST
- Capacitance between traces, membrane: 40pf max
- Capacitance between traces, PCB: 25pf max
- PushGate Mechanical:
- Thickness, flex: 0.086"
- Thickness, PCB: 0.145"
- External magnetic field: no effect
- Armature material: soft steel - 1008/1010 with electronickel & tin plating
- Life expectancy, cycles: in excess of 450 million actuations
- Switch travel: 0.012"
- Contact bounce: 1ms typical
- PushGate Environmental:
- Operating and storage temperature: -40º to 85ºC
- Mechanical shock: no closures at 100 Gs
Please click on the links to the right for more information or request a quote today!