What are gaskets and when to consider them for your keypad?

What is a gasket mount?

Let’s start by defining a keypad’s mounting style. A mounting style describes how the plate or PCB is secured in the keypad’s housing. Given that such components need to be secured within the keypad’s structure, manufacturers came up with several methods of achieving that. While some types of mounting are rigid, others offer more flexibility. The mounting style will affect the assembly method, the sound keys make when pressed, and the general typing feel of the board.

A gasket mount is a mounting style that locates a gasket material between the plate and keypad housing. This material goes both on the top and bottom sides of the board. As a result, the board gets a more cushioned feel because the plate isn’t in direct contact with other metal components of the keypad. A gasket mount can be made of many different materials and form factors.

NEMA ratings are an important aspect of gasketing. The National Electrical Manufacturers Association (NEMA) is a non-profit organization that was established to establish professional requirements for the manufacture of electrical and medical imaging equipment. NEMA works to create industry standards in the areas of protection, innovation, interoperability, the environment, and business development. NEMA ratings define degrees of protection against substances such as water and dust.

Gasket mount – pros and cons

The undeniable advantage of a gasket mount is that it tends to make keypads quieter in operation. The cushioned feel dampens the sound and feel of the keypad.

Another pro of using a gasket mount is that it helps to seal the keypad against moisture. This is especially important for appliances that are used in humid environments where moisture could affect their operation.

Does a gasket mount come with any disadvantages? The only con is the fact that it tends to be more expensive than alternative mounting styles.

Why use gasket mounts? Case study

Our customer, an industry leader in at-home beauty devices, came to us with an issue that consumers were having with one of their products. Customers complained to the company’s distributor that the system stopped working after a while.

Challenge

The product was a skincare device composed of a membrane switch with an on/off control keypad, vibration level, and displacement were included in the product. The keypad was often exposed to condensation moisture due to the product’s use case (but not submersion).

The keypad, which a different vendor had designed, became a problem after the distributor started getting feedback from customers who claimed the system had stopped working over time.

Our team discovered that the development of crystalline dendritic structures allowed the conductive silver traces to scatter over the conductive silver membrane switch tracks. This is called silver migration.

Solution

We suggested a temporary fix for the issue in the form of RTV silicone adhesive added to the tail escape site during assembly. The construction of a completely sealed membrane switch gasket was made possible by using next-generation plastic molds.

Get high-quality keypads from Melrose

Our experienced engineers know how to design switches and keypads that have a soft tactical feel, improving the user experience of every product we manufacture. Longevity, adaptability, and usability are all key factors we take into account when designing products for our customers.

Melrose offers a variety of options, so you’re likely to find a combination that suits your needs best. Get in touch with our consultants to secure high-quality keypads and membrane switches for your application.