Thermal Materials : Thermal Substrates : Fans and Blowers : Membrane Switches : Touch Screens

HeatSeal Reliability
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HeatSeal Data Sheet

HeatSeal Reliability

Bergquist’s exclusive HeatSeal fabrication process thermally bonds switch layers together with heat and pressure. The lamination strength is superior to pressure-sensitive adhesive construction and there is no need to externally vent the spacer layer. The result is a totally sealed switch that helps eliminate inadequate sealing of switch layers, a major cause of failure.

Bergquist rigorously tests our switches before, during and after production. Click on the information tabs below for more information regarding test data.

Inadequate sealing of switch layers is a major cause of failure. Moisture, temperature extremes, and chemicals are typical enemies of standard PSA (pressure-sensitive adhesive) membrane switches. To overcome this issue, Bergquist's exclusive HeatSeal fabrication process thermally bonds switch layers together with heat and pressure. The lamination strength is superior to pressure-sensitive adhesive construction and there is no need to externally vent the spacer layer. The result is a totally sealed switch which protects the electrical integrity of your membrane switch.

THE BERGQUIST ADVANTAGE HeatSeal Holds Up Under Pressure

Pressure Sensitive Adhesive Switches

Typical air distribution within a pressure sensitive adhesive (PSA) membrane switch remains constant (see Figure 1).

When the switch is used at altitudes higher than the point of manufacture (i.e. airliners), the air pressure difference within the switch increases and becomes great enough to escape through the micro fissures in PSA until the air pressure difference between the switch and the environment is equalized (see Figure 2).

Once the air has escaped from the switch and the switch is returned to a normal elevation, the memory within the polyester does not have enough force to draw air back into the micro fissure cavities. The end result is collapsed, electrically shorted switches (see Figure 3).

HeatSeal Switches

Typical distribution of air within a HeatSeal membrane switch is also constant after manufacture (see Figure 4).

When the switch is used at altitudes higher than the point of manufacture, the air pressure difference increases. With Bergquist's unique HeatSeal process, however, the bond strength between the polyester layers is so strong, no air escapes (see Figure 5).

Once the HeatSeal switch is returned to a normal elevation, the air pressure difference is reduced and it returns to its original state of equilibrium (see Figure 6).