Silver Flex Circuits

Silver flex membrane switches represent the most popular electronic interface solutions due to their affordability. ThinSilver Flex Circuit flexible layers preserve a low profile without compromising versatility in design options.

Conductive silver inks are screen printed directly onto a flexible film substrate.  This process is more cost-effective than the chemically etched copper, and poses less potential threat to the environment.

Silver flex switches are considered the most popular for custom membrane switches and keypads.

In its simplest form, a flexible circuit is a vast cumulation of conductors bonded to a thin dielectric, or insulating, film.

Silver or copper may be used as an electric conductor.  Silver Flex Circuits are a popular alternative to Copper Flex Circuits.  Silver ink conductors are added to the flexible film substrate using a screen-printing process, making it the more popular and cost-effective choice.  In a Copper Flex Circuit, a very thin sheet of copper is first laminated to the flexible film substrate then chemically etched away, leaving copper traces.  The etching process is not as environmentally friendly and more expensive than screen-printing silver traces.

Silver flex circuit options include:

  • Single-sided
  • Double-sided (thru-hole)
  • Heat stabilized polyester
  • Embedded SMD (LEDs)
  • Carbon overcoat
  • Printed resistors

Comparison Chart

Characteristic

Silver Ink

Copper

Printing vs. Etching

Conductive silver ink traces are screen printed onto the film substrate. 

Copper is chemically etched away, leaving conductive traces.  More expensive than screen-printing.

Pliability/Weight

Silver traces are lightweight and more flexible than solid copper traces.

Solid copper traces are heavier and more durable than softer printed silver traces.

Conductivity

Resistivity approx 50 mOhms/sq
1mm x 80 mm trace = 4 Ohms
0.5mm x 80mm trace = 8 Ohms

Lower electrical resistance and higher conductivity.

Price

Low to Moderate

Expensive to very expensive

Soldering

No. Components are attached with conductive adhesive.

Ability to solder active and passive components into the switch design.

Pitch

Minimum of 1.00mm.

Possible pitch 0.5mm and 0.3mm for ZIF connector