Applications of Rubber Keypads

Miniature QWERTY keypad – Education Market

Project: To replace a simple numeric pad with a QWERTY style keypad whilst maintaining similar overall product dimensions.

Due to space constraints it was impossible to use rubber keypad technology alone. A solution was created using a Silicone Rubber mid layer to create the key travel, then Plastic key-tops were bonded on to the Rubber Mat and a Mylar Dome Layer was used to create the tactile response. A plastic former was also added to maintain the spacing between the switch caps during operation.

Prototypes were produced in 12 weeks and full production commenced 3 months later after extensive laboratory life testing in our factory. This project also required logistics support for the subcontract manufacturer who was based in the Far East. Diamond HMI’s own Far East staff managed to manage this process.

Further additions included multiple language/colour versions which were in production within 8 weeks of being requested.

COMBIKEYTM Keypad for Industrial Process Control application

Project: The OEM customer used Membrane Keyboards for their Process Control applications but were looking to create a more innovative solution which was visually more appealing and offered greater user feedback. One field issue that we had to address was the lack of tactile response for operatives when operating Membrane Keypads with gloved hands.

After an initial design review it was clear that COMBIKEY™ technology would be the ideal solution for this application. Using a moulded Silicone Rubber front layer designed to match both the case shape and their corporate colours, we added a Membrane Switching layer with High Actuation Force Metal Domes. The final assembled Keypads with encapsulated LEDs was connected to the electronics using a single membrane tail.

The final design provided the user feedback required and was truly innovative in their market with the concept being adopted in their other worldwide locations.

Silicone Rubber Keypad for Power Wheelchair application.

Project: The customer wanted to replace mechanical switches with a more aesthetically pleasing solution which needed to form part of the controller design. The final Keypad Design helped to create the shape of the controller and fitted, using adhesive, into a recess in the plastic case.

An additional requirement was to meet very strict force and travel guidelines which , from their experience, best suited their customers. The criteria was for longer travel and lower tactile response whilst maintaining a long life expectancy. Our designer experimented with a number of web designs and shore hardness’s of rubber before undertaking extended lab testing to prove operating life.

As the project has developed further variants have been produced to accommodate different user profiles and markets.

Silicone Rubber Keypad for Wireless Vehicle control system for Mobility applications

Project: The customer in the Mobility market was looking for a suite of Silicone Rubber keypads based on a set overall size to fit their outer casing design. Each of their applications required a different number of keys to access the products full range of functions.

The customer chose a metallic finish which gives a high quality look to the parts and we also used laser etching to create icons which could be subtlety lit via LED’s placed on the switching PCB.

COMBIKEY™ Keypad for Digital Pocket Manometer

In keypads suitable for a Hand Held devices the key feedback is vital to ensuring that the product is usable in the field.

After a design review this customer specified a COMBIKEY™ keypad with very prominent individually shaped keys. Excellent user feedback was created by combining a metal dome within the circuitry layer and then bonding this to the silicone front layer.

The keypad locates simply into a recess in the instrument casing and is connected to the electronics by a flexible tail. The unbroken adhesive layer gives the high degree of sealing against moisture ingress.