Given Imaging, a medical technology company, came to GM Nameplate (GMN) to assemble a membrane switch panel for their medical device. When configuring a membrane switch, many factors about each component layer must be taken into consideration.
As the user interface for a medical device, the screen printed and embossed overlay needed to satisfy stringent requirements. The overlay must act as a sealant to prevent moisture and fluids from reaching the membrane. Additionally, the overlay must be chemical and scratch resistant to combat the strain of daily use.
Common overlay materials include polyester and polycarbonate. Both materials are affordable options that will protect the circuit membrane from scratches, chemicals, and liquids. Due to the durability of screen printed inks, backprinting is a frequent practice to mitigate product wear and tear from everyday use.
This Given Imaging overlay contains three colors - teal, white, and a black opaque layer. The opaquing layer was selectively applied around the LEDs which allowed light to shine through and prevented light bleed through unwanted areas of the overlay. Because of the opaquing layer, light only showed through the indicator icon on a button instead of throughout the whole part.
When looking at membrane circuit materials, printed silver ink in lower volumes provides a cheaper option than copper etched circuits, such as Kapton, while still offering comparable performance capabilities. Finding the right membrane circuit for the product application is necessary to manufacture a quality membrane switch.
For more information about GMN’s membrane switch assemblies, visit our capabilities page.