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22

Glossary 
Appendix D 
 

Actuation Force-

 The maximum force measured prior to or including the point at which keypad contact 

closure is achieved. 
 

Alodine-

 A chemical conversion process that oxidizes aluminum to form a non-porous aluminum oxide.  

Referred to as “poor-man’s anodizing” because it is less costly and not as durable as anodizing. 
 

Anodize- 

Electro-chemical oxidation of aluminum to form aluminum oxide with a porous nature.  The 

anodized layer can be durably colored and is non-conductive, non-corrosive and resistant to abrasion. 
 

Arcing- 

Discharge of electricity (a spark) that can occur when contacts are opened or closed. Arcing can 

degrade or burn contacts, reducing useful life. 
 

Backlighting-

 A flexible layer within a membrane switch construction that illuminates select areas of the 

overlay, such as text or graphic symbols.  Examples of backlighting methods are E.L. (electroluminescent) 
or fiber optic. 
 

Circuit- 

Functioning component (sub-layer) of a membrane switch.  Typically made of a silver conductive ink 

printed on polyester. Also can be a flexible copper circuit, a PCB or polyester printed with other conductive 
materials. 
 

Contact Bounce- 

(Make) – Point at which specified resistance is achieved. 

 

Dead Front- 

Printing translucent ink in an area so that the graphic is visible only when backlit. 

 

Density- 

The degree to which light transmits through a color or transparent window.  The higher the density, 

the less light will be transmitted. 
 

Dielectric Strength- 

The voltage that an insulating material can withstand before breakdown occurs, usually 

expressed as a voltage gradient (such as volts per mil.) 
 

E.M.I. (also R.F.I)- 

Electromagnetic Interference (Radio Frequency Interference.)  Radiated energy from 

electrical devices, lightning and similar sources which interferes with the proper operation of electronic 
circuitry. 
 

E.S.D.- 

Electrostatic Discharge – transfer of high potential electrical charge between objects by contact or 

through air. 
 

Files- 

Information or documentation created electronically by computer. 

 

Font- 

A set of characters having a unified design. 

 

Gloss Level- 

The degree of shininess of a particular material, usually specified in percentages such as 75% 

gloss, 90% gloss, and so forth. 
 

Halftone- 

Image made of a pattern of various size and shape dots (newspaper photograph) rather than 

continuous gray. 
 

Image-Setting- 

The process by which electronic files are transferred to film or paper directly from the 

computer (computer onto film technology.) 
 

L.E.D.- 

 Light Emitting Diode. 

 

Membrane Switch- 

A momentary switching device in which at least one contact is made of a flexible 

substrate. 
 

Moisture Resistance- 

Ability of a material to repel moisture either from air or when subjected to water. 

 

Non-Tactile Switch- 

A switch assembly that has a tactile ratio equal to zero. 

Summary of Contents for Membrane

Page 1: ...Membrane Switch Design Guide...

Page 2: ...ncoated polycarbonate is also susceptible to damage from a variety of chemicals If a polycarbonate overlay is going to be in an environment that will subject it to chemicals a hardcoat should be used...

Page 3: ...a color by screen printing or painting on a particular substrate The Munsell Color System identifies colors in terms of three attributes hue value and chroma The physical samples to which we match usi...

Page 4: ...s We have samples of both hydroforming and embossing on polyester and polycarbonate that will help illustrate the different results that can be attained Contact a Holland Nameplate sales engineer to r...

Page 5: ...reedom will allow us to produce a more efficient layout This has the advantage of shorter development time and a simpler circuit layout which could nominally affect switch reliability Membrane switche...

Page 6: ...ted with solder tabs that can be directly soldered onto the circuit board The AMP part number used is 88997 2 The lowest cost alternative is to use a ZIF Zero Insertion Force connector AMP and Molex b...

Page 7: ...ovides a rigid panel and allows for the easy addition of other components such as LEDs and resistors These types of membrane switches are usually supplied with a standard header with pins on 100 cente...

Page 8: ...s are in the 12 to 18 ounce range The tolerance on actuation force is 3 ounces Electrical Performance The great variety of membrane switch designs makes it difficult to outline a general set of specif...

Page 9: ...the overlay the less effect the coating will have on display readability If LED displays are within 062 of the overlay a velvet texture will usually yield acceptable readability For distances greater...

Page 10: ...y common to include small surface mounted LEDs into membrane switches This is a very simple way to add annunciators to a switch A standard membrane switch is not thick enough to accommodate the packag...

Page 11: ...rent mechanical dimensions to allow for assembly tolerances The subpanel should be 020 smaller than the membrane switch in both height and width All cutouts and holes should be 030 larger Cutouts behi...

Page 12: ...005 010 Autoflex EBA Autotype Polyester Yes Matte Yes 94 VTM2 Yes 005 010 Marnot XL Tekra Polycarbonate Yes Various Yes 94 V2 Yes 007 030 8010 Lexan General Electric Polycarbonate No Gloss Yes 94 V2...

Page 13: ...l dimensions of the finished part ___ Tolerance specified 015 Type of switch ___ Non Tactile ___ Tactile with stainless steel domes ___ Tactile with polyester domes Tail details ___ Tail exit point __...

Page 14: ...olycarbonate 8B35 ___ Gloss polycarbonate with hardcoats 8010 ___ Velvet textured polyester with hardcoat Autotype ___ Gloss polyester with hardcoats Autoflex ___ Other _________________ Logos and spe...

Page 15: ...rims ___ Plateau ___ LED windows Insertable legends ___ Not required ___ Specified Support panel ___ LED windows ___ Not required ___ Drawing included with material specified Artwork ___ Holland Namep...

Page 16: ...__ Pantone Matching System ___ Federal Standard No 595a ___ Copy size style and location specified Switch Sealing Requirements ___ Standard splash resistant ___ NEMA 4 Switch Venting Requirements ___...

Page 17: ...17 Membrane Sample Appendix C...

Page 18: ...18...

Page 19: ...19...

Page 20: ...20...

Page 21: ...21...

Page 22: ...ly when backlit Density The degree to which light transmits through a color or transparent window The higher the density the less light will be transmitted Dielectric Strength The voltage that an insu...

Page 23: ...coverage is less than 100 simulating shading or a lighter color Selective Texture A transparent velvet finish printed on specified areas on an overlay to accentuate design elements such as windows ke...

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