Memberane switch

7/29/2019 Memberane switch

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D A W A R T E C H N O L O G I E

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PROTOTYPES:

A prototype is a cost effective way toproduce your design with a minimuminvestment in tooling. Especially if you arnot sure about color, size or shape. Dawahas the printing and laser cutting capabilitito better serve your prototype requirement

OVERLAY MATERIALS:

The overlay is the top layer of amembrane switch and is the interfacebetween you and the machine. The overlacreates the look and feel for your productIt is the first thing your customer sees anhas to be aesthetically pleasing. Dawar haa design team to assist you create the imagyou want to project.

Dawar offers a complete line ofpolycarbonate, polyester or acrylic materiain various gloss levels, textures, pencilhardness and gages to meet your needs.

you have special UL or CSA requirementDawar can make recommendations tocomply with those needs.

Two of the most important issues aredurability and environmental concerns. It essential to choose a material that will oulive your application requirements; poly-carbonate offers more flexibility with regato design but polyester is more durable.

If you have an application for < 50000actuations, polycarbonate is a good choicotherwise polyester is the material of choicLife cycle tests show that polyester can bactuated over 1,000,000 times in a tactileswitch without showing signs of wear. Fogood tactile feedback in a membrane switcchoose an overlay thickness between .00and .010. These thickness ranges will offethe durability to meet your requirements

Dawar has a computerized colorformulation system to achieve consistentresults from printing to printing. Dawar cacolor match to the Pantone MatchingSystem, Federal Standard Guide, a color

swatch or to your bezel. The colors on thoverlay are screen printed on the secondsurface. The thickness of the overlaysprotects the graphics from the environmeand operator wear. Selective textures andwindow clearing agents are printed on thfirst surface and UV cured to produce a vedurable finish.

.335" WITH .060" RA

DIUS CORNERS

PILLOW EMBOSSED K

EYS (13X)

.500" X .335" WITH .06

0" RADIUSCORNERS

PILLOW EMBOSSED K

EYS (3X)

0

0

2.234"

4.724"

.433"

.868"

1.303"

1.738"

2.173"

3.532"

2.8385"

.617"

1.117"

1.617".452"

1.781"

2 .291" X .531"

CLEAR NON-TEXTUR

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SICSDawar Technologies, a 120 year oldcompany has over 14 years experience inmanufacturing membrane switches. Dawar

utilizes the latest in material and designtechnologies. We can manufacture amembrane switch that complies with yourspecs and within your budget. We offerdesign consultations to our customers anddesign options that can reduce costs andcomply with your environmental

requirements.

DESIGN:

Dawar provides the customer with acomplete set of drawings (graphic andelectrical) for the customer to review,approve and retain for their records priorto manufacturing. These drawings alsoflow through the shop during production.

Dawar supports files created inAutoCAD, CorelDraw, FreeHand, Illustrator,PageMaker and QuarkXPress (Ask for our

Computer Graphics Specifications). Wehave an extensive font library, but it isrecommended that you include or embedthe fonts with your file, especially if youhave edited them in some way.

It can also be helpful to send a hardcopy of the artwork. You can email yourfile to [email protected]


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ADHESIVE:

There are numerous differences inadhesives. Selecting the proper adhesivefor a membrane switch application requiresconsideration of environment, surface,appearance and other performancerequirements.

Surface contact is fundamental toadhesive performance. The strength of the

bond is determined by the surface energy.Adhesives are manufactured for applica-tions to these three surface categories:metals, high surface energy and lowsurface energy. Dawar engineers can helpyou select the correct adhesive for yourapplication.

EMBOSSING:

Embossing can dramatically enhancethe look and functionality of the overlay.There are three basic styles of embossing,

pillow, rim and dome embossing.Depending on shape and size, logos andmulti level shapes can be embossed.

There are two ways to emboss anoverlay. The first method is with male andfemale magnesium dies. This method isfine for most applications but there areheight limitations: embossing height isusually 2 to 2-1/2 times the materialthickness, the minimum width of a rimemboss is 0.050", the distance betweenembossed objects should be .100" and the

minimum inside radius should be .005".Hydroforming is the second method whichhas more design flexibility.

CIRCUITS:

Dawar offers screen printed conductivesilver ink circuit, copper flex circuit andprinted circuit boards. The conductive silverink is printed on .005 polyester, resistancerange is


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M E M B R A N E S W I T C H C O N S T R U C T I O

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GRAPHIC OVERLAY

GRAPHIC ADHESIVE

DOME RETAINER

STAINLESS STEELDOMES

SPACER

INTERIOR VENTING

FLEXIBLE TAIL TOCONNECTOR & LOGIC

CIRCUIT

ADHESIVE

RIGID SUB-PLATEOR BACKING (Optional)

Custom TactileMembrane SwitchDesignWithout Shield


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GRAPHIC OVERLAY

GRAPHIC ADHESIVE

RFI/EMI/ESD SHIELD,FIBER OPTICS (Optional)OR EL LIGHTING (Option

TO GROUND ORPOWER SOURCE

DOME RETAINER

STAINLESS STEELDOMES

SPACER

INTERIOR VENTING


CIRCUIT

ADHESIVE

RIGID SUB-PLATEOR BACKING (Optional)

Custom TactileMembrane SwitchDesign WithShield and Backer


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Custom Standard(Non-Tactile)Membrane SwitchDesign WithShield and Backer

GRAPHIC OVERLAY

GRAPHIC ADHESIVE

RFI/EMI/ESD SHIELD,FIBER OPTICS (Optional)OR EL LIGHTING (Option

ADHESIVE

TO GROUND ORPOWER SOURCE

TOP FLEXIBLECONDUCTIVE CIRCUIT


MATRIX OR COMMONBUS CIRCUIT DESIGN

INTERIOR VENTING

SPACER OPENING SIZETO MEET ACTUATIONFORCE REQUIREMENTS

SPACER LAYER6 TO 11 MIL THICK

FLEXIBLE TAIL TO

CONNECTOR & LOGICBOTTOM FLEXIBLECONDUCTIVE CIRCUIT

ADHESIVE

RIGID SUB-PLATEOR BACK ING (Optional )


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ACTUATION

PRESSURE

GRAPHIC OVERLAY

GRAPHIC ADHESIVE

DOME RETAINER

DOME

DOME SPACER

CONDUCTIVE INK

BOTTOM MEMBRANE

Tactile ResponseTechnology


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Custom TactileMembrane SwitchDesign (V1)

ACTUATION

PRESSURE

PILLOW EMBOSSED

GRAPHIC OVERLAY

GRAPHIC ADHESIVE

DOME RETAINER

STAINLESS STEEL DODOME SPACER

12 TO 15 MIL TRAVELTO CLOSE SWITCH

BOTTOM CIRCUIT

REAR ADHESIVE

CONDUCTIVE INK

.027 TO .060TOTAL THICKNESS


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Custom TactileMembrane SwitchDesign (V2)

ACTUATION

PRESSURE

PILLOW EMBOSSED

GRAPHIC OVERLAY

GRAPHIC ADHESIVE

DOME RETAINER


TOP CIRCUIT


BOTTOM CIRCUIT

REAR ADHESIVE

CONDUCTIVE INK.027 TO .060TOTAL THICKNESS


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Custom TactileMembrane SwitchDesign WithSurface MountedL.E.D.S

ADHESIVE

SPACER

ADHESIVE

CONDUCTIVE INK

BOTTOM CIRCUIT

ACTUATION

PRESSURE

PILLOW EMBOSSED

GRAPHIC OVERLAY

GRAPHIC ADHESIVE

DOME RETAINER


TOP CIRCUIT


BOTTOM CIRCUIT

REAR ADHESIVE



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Custom Standard(Non-Tactile)Membrane SwitchDesign

ACTUATION

PRESSURE

PILLOW EMBOSSED

GRAPHIC OVERLAY

GRAPHIC ADHESIVE

TOP CIRCUIT

SPACER6 TO 11 MIL TRAVELTO CLOSE SWITCH

BOTTOM CIRCUIT

REAR ADHESIVE



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ABRASION RESISTANCEAbility to resist surface wear.

ACCELERATED AGINGA test methodology that simulates longterm environmental effects.

ACTUATION FORCEForce required to collapse a metal orpolyester dome.

ADHESIONThe molecular force of attraction betweenunlike materials. The strength of attractionis determined by the surface energy of thematerial. The higher the surface energythe greater the molecular attraction, thelower the surface energy the weaker theattractive force.

AMPERE [AMP]A standard unit of current. Defined as theamount of current that flows when onevolt of EMF is applied across one ohm ofresistance. An ampere of current isproduced by one coulomb of chargepassing a point in one second.

AQLAcceptable quality level.

ASTMAmerican Society for Testing and Materials.

AUTOTEXTrademark for Autotype Industrial Filmspolyester graphic overlay film.

BOND STRENGTHAmount of adhesion between two surfaces.

BREAKDOWN VOLTAGEThe voltage at which the insulationbetween two conductors is destroyed.

CAD/CAM

Computer aided design/Computer-aidedmanufacturing.

CAPACITANCEThe property of conductors and dielectricswhich allows the storage of an electricalcharge when voltage is applied. ASTMF1663-95


G L O S S A R

CARBON/GRAPHITE INKSSpecially prepared suspensions of carboblack; these systems are employed for lowcost when the conductivity of a metal bassystem is not required. Often printed ovesilver circuitry to reduce the potential forsilver migration, also employed for printeresistors.

CERTIFICATE OF COMPLIANCE (C OF C)A certificate generated by a quality controdepartment confirming that the productbeing shipped meets the manufacturingdocument.

CONDUCTIVITYThe ability of a material to allow electronto flow measured by the current per unit voltage applied.

CONTACT BOUNCEIntermittent contact opening and closurethat may occur after switch operation.See ASTM F161-95

CSACanadian Standards Association.

CURRENT, ALTERNATING (AC)An electric current that periodically reversdirection of electron flow. The rate at whica full cycle occurs in a given unit of time(usually a second) is called the frequency

the current.

CURRENT, DIRECT (DC)Electrical current whose electrons flow inone direction only. It may be constant orpulsating as long as it's movement is in thsame direction.

DEAD FRONTCosmetic feature of a graphic overlayallowing for a display feature to be visiblonly when backlit.

DIE CUTTINGProcess for blanking or cutting sheet or romaterials to predetermined shapes formembrane switch components, graphicoverlays and labels.

DIELECTRICAn insulating (nonconducting) medium.M

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G L O S S A R

DOME RETAINERAn adhesive layer designed to hold metaldomes in keys

EL LAMPSA thin (.010"-.025") illuminating deviceemployed to light large areas, commonlyused in LCD, control panel, and membraneswitch backlighting.

EMBEDDED LEDThe practice of encapsulating a surfacemount LED into a membrane switchconstruction.

EMBOSSMechanical and thermoforming of graphicfeatures, providing a raised feature foraccenting key surfaces, logo's, and to allowfor embedding of surface mount LED's

within the switch.

EMBOSS, RAILCreates a raised ridge around the perimeterof the key area, usually.

EMBOSS, PILLOWCreates a raised surface in the graphicoverlay over the entire key area.

EMI/RFI/ESD SHIELDPrinted conductor pattern or separatealuminum or copper film employed in

membrane switch designs to reduce theeffects of electromagnetic and radiofrequency interference.

FIBER OPTIC BACKLIGHTINGIlluminating device employed to light largeareas. Strands of clear fiber are woven andbundled, after polishing the fiber ends areilluminated by an LED or Halogen lamp.

FLAT FLEX CONNECTOR [FFC]Connector type commonly used toterminate membrane switch circuitry.

FONTA set of characters having a unified design.

GLOSS LEVELThe degree of shininess of a substrate,usual specified in percentages for example75% gloss, 90% gloss, etc.

HB-94HBUnderwriters Laboratories flame retardanspecification (horizontal burn)

HSEHigh surface energy.

INSERT LEGEND (INSERT GRAPHICS)A design feature allowing for changes tonomenclature and symbols by the client end user. The feature is accomplished bycreating a pocket in the membrane switcassembly to allow for an insert card.

INTERNALLY VENTEDSwitch openings are connected to each othbut not to the outside atmosphere. Thisdesign approach is used to seal the switcfrom moisture and contaminants.

ISOInternational Standards Organization. Knowfor the development of a series of standardcalled ISO 9000 for developing Total QualiManagement, and creating a continuousQuality Improvement Process.

ITOIndium Tin Oxide, a thin film conductivematerial vacuum deposited on the surfacof a film substrate. Material is often the basmaterial for resistive touchscreens.

KEY HEIGHTThe measured distance from the bottom(base) of the keypad to the top surface ofthe key.

KEY TRAVELThe distance a switch moves to close anelectrical contact, expressed in inches orMM.

LEDLight emitting diode.

LEXANGeneral Electric (GE) registered trademarfor polycarbonate film.

LSELow surface energy.

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G L O S S A R

MEMBRANE SWITCHA momentary switching device in whichat least one contact is on or made of, aflexible substrate.

METAL DOMEStainless Steel Disc or element. One ofseveral approaches used to produce tactileresponse.

MOISTURE RESISTANCEThe ability of a material to resist absorbingmoisture from the air or when immersedin water.

MPModified performance. An adhesiveclassification of 3M products.

MUNSELL

Color matching system which defines colorby three attributes; hue, value, chroma.Fifteen hundred color samples are availableas opaque pigmented films.

MYLARDupont trademark for polyethyleneterephtalate (polyester) film.

NEMANational Electrical ManufacturersAssociation.

NON-TACTILEMembrane switch constructed withoutsnap action.

OHMThe electrical unit of resistance. The valueof resistance through which a potentialdifference of one volt will maintain a currentof one ampere.

OVERLAYDecorative front layer of a membraneswitch or control panel.

OVER-TRAVELThe additional travel of a rubber keypador metal dome after making contact withthe circuit.

PANTONE MATCHING SYSTEM (PMS)Color matching system originally developefor the offset printing industry, commonlyused in the membrane switch industry foits broad acceptance, range of colors andease of use. Over 1000 colors are cataloge

PCBPrinted circuit board.

PINOUTThe schematic describing the circuit outprequirements for a membrane switch orother electronic device.

POLYCARBONATEGraphic overlay film widely used for contrpanels

POLYESTER DOME

A spherically formed element in polyestecircuit material to provide tactile responsin membrane switches. Usually the domeare formed in arrays or sets to match thekey configuration of the keypad. Polydome

POLYESTERBi-axialy oriented polyethylene terephthalafilm. (PET)

PRESSURE-SENSITIVEAdhesive materials which bond with theapplication of pressure alone and do not

require activation by heat or solvents.

RESISTANCEIn DC circuits, the opposition a material offeto current flow, measured in Ohms.RFI Radio Frequency Interference.

SCREEN PRINTINGPrinting process using a mesh stretched ova frame allowing ink to selectively passthrough by using a stencil. The process mocommonly used for producing graphicoverlays and membrane switch circuits.

SECOND SURFACE PRINTEDInks are applied to the non-exposed side the film to allow for the film to protect thinks from scratching or damage.

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Certified to ISO 9001:2000


G L O S S A R

SELECTIVE TEXTURINGThe creation of surface effects on matteor gloss films normally applied using thescreen printing process.

SILICONE RUBBERRubber made from silicone elastomersand noted for its retention of flexibility,resilience and tensile strength over awide temperature range.

SILVER INKSSpecially prepared suspensions of finelymilled silver particles in a variety of resinsystems are used widely to produceconductive patterns on flexible substrates.

SPACERAn adhesive layer of a membrane switchused to separate circuit layers and to provide

key openings allowing for conductors tocontact each other when depressed.

STATIC SHIELDPrinted conductor pattern or separatealuminum or copper film employed inmembrane switch designs to reducethe effects of static discharges.

STEEL RULE DIEConsists of a .750-.875 thick die-board(plywood construction) with .937" highknives inserted into laser cut groves.

TACTILE SWITCHA switch or switch assembly providing apositive snap-action response. Theresponse can be achieved through theuse of stainless steel domes embeddedin the membrane switch, or polyesterdomes formed in either the circuit orgraphic overlay layers.

THIXOTROPHYThe property of a coating or ink, whichhas a low viscosity when agitated, butthickens when agitation ceases.

VISIBLE LIGHT TRANSMISSION (%)The ratio of the amount of total visiblesolar energy (370-780 nanometers) thatis allowed to pass through a filter, to theamount of total solar energy falling onthat filter.

WATTA unit of electrical power. One Watt isequivalent to the power represented by onampere of current with a pressure of onevolt in a DC circuit.

ZIFZero Insertion force.

the ultimate impression

t e c h n o l o g i e s

1020 Ridge Avenue, Pittsburgh, PA 152331-800-366-1904 412-322-9900 / FAX: 412-322-9958

[email protected]

For more details on products and servicesgo to www.dawar.com

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Memberane switch