PET Membrane Switch
What is a membrane switch? A membrane switch or flat switch consists of a printed polyester or polycarbonate overlay that adheres to a printed circuit, using pressure to open and close the circuit. A membrane switch is considered a "momentary action" switch, meaning that the switch is essentially always on, but when the switch is pressed, the circuit is temporarily closed, activating the key function. The switch is a critical aspect of the end product as it is the interface between the user and the machine, enabling the operator to communicate with the equipment, instrument or machinery. The membrane switch circuit is screen printed using conductive inks that are typically made of silver or carbon. Membrane switches are part of a range of devices that are considered user interfaces or human machine interfaces. We are a leading global manufacturer of custom membrane switches and custom keyboards. With our unlimited design and manufacturing capabilities, we are able to provide our customers with custom tactile membrane keyboards and custom keyboards to meet their needs as user interfaces and product panels. We design and manufacture custom membrane switch and membrane keyboard technology to meet our customers' specific requirements in terms of performance and visual aesthetics.
Flexible Circuts(FPC Membrane Keypad)
Copper flex circuits are used in most of our custom keyboard designs because of its excellent dielectric strength, thermal stability, chemical resistance, and flexibility. Copper flex circuits, also known as Kapton circuits, have become a better choice than printed silver circuits, especially for outdoor applications. Printed silver circuits can be replaced with copper and polyimide structures at minimal additional cost. Copper flex circuit structural designs offer significant advantages over printed silver circuits. Copper flexible membrane switch panels are produced using polyimide (Kapton) as the base material. Copper flex keypad switches are manufactured by laminating thin sheets of copper to a flexible film substrate. The copper is then removed through chemical etching, leaving copper traces. Laminate another layer of polyimide to the circuit, leaving the gold contacts exposed.
Flex circuits offer the following advantages over printed silver circuits: Improved foldability – able to be folded or creased without causing breaks, which can easily happen with silver ink Ability to place soldered components directly onto the flex, with better adhesion than silver ink adhesion More resistant to thermal shock No potential issues with silver migration Higher conductivity Lower closed loop resistance and switch bounce will be reduced with gold plated contacts. Instead of a silver to gold dome, we will have a gold to gold contact with no bounce. Strengthening ribs are applied to the tail using hot lamination instead of cold lamination, which provides better adhesion and is better for fixturing Ability to achieve 0.5mm pitch, versus 1.0mm minimum pitch with printed silver Tighter trace routing capabilities.
Single-Sided and Double-Sided Flex Circuits Single-sided flex circuits consist of a single copper conductor layer on a flexible dielectric film. These flex circuits can be manufactured with or without a cover layer. Double-Sided flex circuits consist of two copper layers encapsulated with a dielectric, usually connected with plated through holes. The circuits can also be manufactured with or without a cover layer.
Multilayer Flex Circuits Multilayer flex circuits consist of 3-6 copper layers encapsulated with dielectric, typically connected with plated through holes.
Rigid Flex Circuits Rigid flex circuits have conductors on both the flexible and rigid layers of the circuit. Plated thru holes extend between the flexible and rigid sections and electrically connect multiple conductor layers.
Backlighting
Backlit membrane switches are suitable for any industry and are often used in military and aerospace applications to help users better interact with a customer's product or instrument. A backlit membrane keyboard or interface can also help a product stand out from the competition because it makes the keyboard appear clearer and is ideal for low-light environments.
Backlight Selection
Single-Sided and Double-Sided Flex Circuits Single-sided flex circuits consist of a single copper conductor layer on a flexible dielectric film. These flex circuits can be manufactured with or without a cover layer. Double-Sided flex circuits consist of two copper layers encapsulated with a dielectric, usually connected with plated through holes. The circuits can also be manufactured with or without a cover layer.
Multilayer Flex Circuits Multilayer flex circuits consist of 3-6 copper layers encapsulated with dielectric, typically connected with plated through holes.
Rigid Flex Circuits Rigid flex circuits have conductors on both the flexible and rigid layers of the circuit. Plated thru holes extend between the flexible and rigid sections and electrically connect multiple conductor layers.
Graphic Overlays
Backlit membrane switches are suitable for any industry and are often used in military and aerospace applications to help users better interact with a customer's product or instrument. A backlit membrane keyboard or interface can also help a product stand out from the competition because it makes the keyboard appear clearer and is ideal for low-light environments.
There are a number of elements to consider when designing your graphic overlay:
Substrates:
Polyester
Polycarbonate
Window and Lenses:
Clear LCD or LED
ITO using optical clear lamination
Dead front Smoked as well as translucent colors for backlighting
Surface Finishes:
Velvet
Gloss
Anti-reflective
Anti-microbial
In-House Embossing & Forming:
Pillow, rim, finger guide, LED, braille
Cold and hot embossing Hydroforming
Adhesives:
3M 467 or 468
3M 300LSE
3M VHB Foam
Cutting:
Laser traced steel rule dies
Tinplate high precision tools
Laser and CNC cutting
Printing:
Screen printing
Digital printing