A Definition of Membrane Switch Adhesives
Membrane switch adhesives are used to mount membrane switch assemblies to the application. These adhesives are positioned on the mounting surface of the membrane switch, although in some cases, membrane switch assemblies containing more than one circuit layer will also include an adhesive spacer, or adhesive separator, between circuit layers.
The goal of membrane switch adhesive is to ensure the membrane switch assembly remains securely adhered throughout the life of the product. Early adhesive failures can lead to a loss of customer loyalty and repeat business, making the choice of adhesives a serious consideration in the membrane switch design process. While adhesive is not a visual element impacting the outward appearance of a membrane switch or product, the right adhesive ensures reliability and durability, fostering customer loyalty.
Types of Rear Adhesives for Membrane Switch Assemblies
Most membrane switches use 3M 467MP pressure sensitive adhesive as the rear adhesive layer, although 3M makes a variety of membrane switch adhesive options. If a membrane switch is adhering to a rough surface, 3M 468MP pressure sensitive adhesive is generally recommended. For specialty applications, many different adhesives are designed to meet a variety of application specifications.
Membrane switch adhesive performance is critical to the integrity of the membrane switch assembly; therefore, selecting the best adhesive option for the application is one of the most important design considerations. The adhesive selected must consistently perform and meet expectations, including resistance to harsh chemicals or solvents, high temperatures, moisture or humidity, and UV, as required.
Benefits of 3M Membrane Switch Adhesive
3M is a leading manufacturer of membrane switch adhesives, offering a number of benefits for membrane switch design engineers and product manufacturers. From excellent moisture and solvent resistance to exceptional resistance to high temperatures and a high shear strength to withstand the ongoing stress from repeated actuation, 3M membrane switch adhesives are a viable option for a great many membrane switch applications.
3M membrane switch adhesives may also be die-cut, allowing for the use of these adhesives in applications in which selective die-cutting is necessary or desirable. These benefits coupled with UV resistance and easy application make 3M membrane switch adhesives a leading choice among membrane switch designers, although other options do exist in the market. Available in sheets, custom sizes, and rolls, there are a multitude of options to choose from depending on your design and production requirements.
Whatever membrane switch adhesive you choose, be sure the adhesive is durable enough to withstand the repeated stress of actuation as well as hold up to environmental hazards, cleaners and solvents, and other conditions that may exist in the anticipated use environment for the application.
How Membrane Switch Adhesives Work
Membrane switch adhesives work by creating a permanent bond between the membrane switch assembly and the application. Positioned on the mounting surface of the membrane switch, membrane switch adhesives provide one option for mounting the membrane switch to the application. Alternatively, should membrane switch adhesive options be determined inadequate to meet the application’s specifications and requirements, other mechanical mounting options may be considered.
Membrane switch adhesives are available with both high and low surface energy adhesives. These selections enable designers to select the best adhesive for the application, offering the ability to create a permanent bond with metal or high surface energy plastics, for example.
Ideal Membrane Switch Adhesive Application Technique
The bond strength of membrane switch adhesive is dependent on the amount of adhesive-to-surface contact developed. Firm application pressure develops better adhesive contact and thus improves bond strength. To obtain optimum adhesion, the bonding surfaces must be clean and dry.
If alignment is a problem, beginning in the top corner and stick down a small amount of adhesive is recommended. Then remove the rest of the liner and work your way down, applying pressure as you apply the adhesive. This adhesive will take approximately 72 hours to fully cure from the time of initial bond.
Remember, choosing the right membrane switch adhesive for your application is the key to the success of your project and key to the longevity of your membrane switch application. Consider the environmental conditions in which the product will be typically used, thickness, and other factors, weighing these considerations against the features, durability, and performance offered by various membrane switch adhesive options to select the best adhesive for your application.