Membrane keyboard repair or membrane keyboard reproduction
Repairing a membrane keyboard is usually not possible, so replication is usually the only option left. In this article, we explain how a membrane keyboard is constructed and why it is easier to replicate it than to repair it. There are several reasons why a membrane keyboard may be damaged or defective. For example, liquids or dirt can get between the membranes. Oxidation of the contacts and contact surfaces is also a common problem.
Construction of a membrane keyboard
A membrane keyboard consists of several layers that are firmly glued together. The bonded layers cannot be separated without damage, which is why it is usually not possible to repair a membrane keyboard. The keyboard itself is also firmly glued to the device, which makes removing the membrane keyboard without damage difficult. The image shows a schematic side view of a membrane keyboard. Below you will find a brief explanation of the layers.
Top layer of the keyboard
The top layer of the membrane keyboard consists of a printed, abrasion-resistant plastic film with an adhesive surface on the back. The adhesive is omitted in the key areas so that the film does not stick to the actual switch. Optionally, the film can be embossed at the keys, which visually highlights the key from the rest of the film and makes it tactile.
spacer layer
This layer is optional and is usually a transparent plastic film. This is used to provide more space for the snap domes (also referred to as click frog referred to as) or to provide the rubber buttons. If the keys are embossed in the front membrane, this layer is usually not necessary.
electronic layer
The second layer is the actual electronics of the keyboard and consists of a printed circuit board or circuit foil. Depending on the design of the membrane keyboard, this layer consists of a circuit foil with metal domes or a conductive rubber button, or alternatively of two bonded circuit foils that are pressed together when a key is pressed. This layer is then glued to the device using adhesive. The electronic layer is connected to the actual device either with a plug or with an extended flexible circuit board (flex PCB).
Replicating instead of repairing membrane keyboard
Repairing a membrane keyboard is unfortunately not always possible, so reproduction is often the last resort for repairing old machines without spare parts. For simple membrane keyboards, the development costs for the first unit range between €500 and €1,000, depending on the effort involved. The production of subsequent units is then much cheaper. Therefore, reproduction is usually only worthwhile for large machines, or if more than one membrane keyboard is needed. Send us pictures, dimensions and the required quantity of the membrane keyboard by email or contact form, and we will prepare a non-binding quotation.
Develop new membrane keypad
We have the necessary know-how and technical capabilities to develop membrane keypads according to specific requirements. We use only high-quality materials and ensure that the new keypad functions reliably and is durable. Our custom-made membrane keypads are perfectly suited for companies that have special requirements or need specific functions. We work closely with our customers to develop a membrane keypad that meets their requirements and expectations. For further information, please feel free to contact us at any time. For more detailed information on the development process itself, you can read our article Hardware development look at.
Examples of reproduced membrane keypads
In the meantime, we have already replicated a number of membrane keyboards. In the illustration, you will find two membranes and four replacement circuit boards for repairing or replacing membrane keyboards. Depending on requirements, these boards are produced as FR4 PCBs or flexible PCBs. The brown/gold board in the middle is a flexible circuit board, whereas the red, green, and black ones are standard FR4 PCBs. Whenever possible, for straightforward repairs we only manufacture a circuit board with mechanical switches, which is installed beneath the original membrane. If that is not possible, we manufacture a new membrane along with the matching circuit board. If you are interested in the repair process itself, I can send you the article Circuit board repair or Electronics repair recommend.
Mosertronik – your partner for repair and small-batch development
If you have problems with your membrane keypad or need a new one, please feel free to contact us. We offer you a fast and reliable solution at fair prices. Contact us for further information.
