How to Choose the Right Materials for Your Etched Foil Heating Element

As etched foil heating elements become increasingly popular among engineers who must offer advanced thermal management in applications that lack space, it is important to make the most of your metal alloy and base laminate material selection.

The choice for metal alloy will depend on your manufacturing process, application needs and buying requirements. Every metal alloy has unique physical, mechanical and surface properties as well as cost, service and fabrication considerations.

At Switzer, the following metal alloys are available for your etched foil heating elements:

• Inconel
• Copper
• Beryllium Copper
• Phosphor Bronze
• Nickel
• Stainless Steel
• Nichrome

Following that selection, you will need to laminate the foil to the base substrate. This bond must be strong enough to handle chemical etching, stripping and cleaning cycles.

Two of the most commonly used base laminate materials for etched foil heating elements are polyimide and silicone rubber. These materials both serve as effective carriers for the foil, but each offer unique advantages.

Polyimide

Flexible heaters made of polyimide typically consist of an etched foil heating element in between two layers of polyimide film. This thinness allows it to fit in tight spaces, but the necessary adhesive cannot withstand extremely high temperatures.

• Withstands temperatures as high as 300°F (150°C)
• Typically manufactured less than 0.007-in. thick (without the mounting adhesive)
• Low profile allows it to wrap tightly around curved and irregular surfaces
• Provide short thermal response times
• Ideal for 2D applications
• Water- and chemical-resistant

Silicone Rubber

Conversely, silicone rubber adds more thermal insulation to an etched foiling heating element and can endure higher temperatures. This option is also thicker, which ultimately limits the bend radius.

• Withstands temperatures as high as 455°F (235°C)
• Typically manufactured as thin as 0.030 inches
• Ideal fo high temperatures in outdoor environments
• Can fit on 3D applications

In addition to these materials, Switzer also offers the following base laminates for etched foil heating elements:

• Silicone
• Neoprene
• Fabric (reinforcing or layer)
• Kapton/Polyimide

Knowing your options is key to making an informed decision. The Switzer team is here to help though. We offer material consultations to ensure you can find the ideal metal alloy foil and base laminate combination for an etched foil heating element that will expertly control temperatures. Schedule yours today!