Holland Membrane Ultraviolet Hardcoats, Embossing, Cosmetic Inspection, Mechanical Tolerances

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Ultraviolet Hardcoats

The most durable hardcoats are those that are cured by exposure to ultraviolet light. These coatings are called UV hard-coats. Hardcoats can be selectively added to many of the materials to produce parts with a velvet textured background, and gloss or anti-glare windows.

Embossing

In many applications it is desirable to emboss or hydroform the keys of a switch. The phrase “Plateau Embossing” is used to describe keys that are raised and flat on the top. The term “Rim Embossing” is used to describe raising only the border of a key. Embossing is typically .010" high and two dimensional.

Hydroforming can be used to attain higher embossments, up to 2-3 times material thickness. Three dimensional dies can also be built. Overlays can be hydroformed with domes in them to provide tactile feedback. Hydroforming tools are significantly more expensive than embossing tools.

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 request hydroforming and embossing samples.

Cosmetic Inspection

In evaluating the cosmetic attributes of a membrane switch, it is important that the vendor and the customer have a common understanding of how the part will be inspected, and what the criteria for evaluation will be. To facilitate this Holland Nameplate has developed a standard cosmetic inspection specification. In the absence of a customer specification we will use this standard.

This standard is also useful in setting a standard format for specifying cosmetic inspection requirements. It is recommended that in cases where the customer desires to establish his own inspection criteria, the format of our specification be used.

The key requirements include viewing time, viewing angle, viewing distance, and defect size.

Mechanical Tolerances

Steel rule dies are usually used to fabricate the various layers of a membrane

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Contents Membrane Switch Design Guide Overlay Materials IntroductionArtwork Color Matching Ultraviolet Hardcoats EmbossingCosmetic Inspection Mechanical TolerancesPinouts Laser CuttingESD/RFI Shielding Interconnect Tail Exit PointScreen Printed Flex Circuits Creasing of Flex Circuits Rigid Membrane SwitchesDomes Operating Temperature Range Actuation ForceElectrical Performance Loop ResistanceWindows Life Cycle TestingInsertable Legends Embedded LEDs Thick Film ResistorsMounting Adhesives Subpanels Drawings and SpecificationsBacklighting Holland Nameplate Overlay Material Guide Appendix a EBAType of switch Tail detailsTail termination PinoutShielding Overlay MaterialLogos and special graphics Windows/Lens coatingEmbossing HydroformingInsertable legends Support panelSwitch Venting Requirements Switch Sealing RequirementsColor matching Membrane Sample Appendix C Page Page Page Page Glossary Appendix D