Do membrane keyboards have switches?

A membrane keyboard is a collection of multiple switches. It is a type of keyboard composed of multiple layers of film materials. It usually includes a panel layer, an isolation layer, a circuit layer, and a backing layer. The “switch” in a membrane keyboard is to achieve the on and off of the circuit through the deformation of the film material, and there is no movable part of a traditional mechanical switch.

What are the components of a membrane keyboard?

Membrane keyboards are mainly composed of the following components:

• Panel layer: The panel layer is usually made of colorless and transparent sheets such as PET and PC, and is silk-screened with exquisite patterns and text. Its main function is to mark and press keys, so the material must have high transparency, high ink adhesion, high elasticity and high toughness.

• Surface glue layer: The main function of the surface glue layer is to closely connect the panel layer with the circuit layer to achieve the effect of sealing and connection. Its thickness is generally between 0.05-0.15MM, with high viscosity and anti-aging properties.

• Control circuit upper and lower layers: These two layers use polyester film (PET) with good performance as the carrier of the switch circuit pattern, and conductive silver paste and conductive carbon paste are screen-printed on it with a special process to make it conductive.

• Interlayer: The interlayer is located between the upper circuit and the lower circuit layer, which plays a role of sealing and connection. PET double-sided adhesive is usually used.

• Back adhesive layer: The use of back adhesive is closely related to the material to which the membrane switch is attached. Commonly used ones include ordinary double-sided adhesive, 3M adhesive, waterproof adhesive, etc.

What type of keyboard has switches?

Mechanical keyboards are keyboards with switches. Each key of a mechanical keyboard has a separate switch to control the closure.

Mechanical keyboards use independent micro switches to realize key operation. The switch action of each key has a clear sense of paragraph and feedback, which makes the feel very clear and stable.

What do membrane switches look like?

Membrane switches are an operating system that integrates key functions, indicating elements, and instrument panels. It consists of four parts: panel, upper circuit, isolation layer, and lower circuit.

The structure of the membrane switch includes:

• Panel: the part that the user directly contacts, usually with an aesthetic appearance.

• Upper circuit: conductive film, which deforms when subjected to pressure.

• Isolation layer: insulating layer, preventing the upper and lower circuits from directly contacting each other.

• Lower circuit: fixed circuit, which conducts signals when in contact with the upper circuit.

The working principle of the membrane switch is that when the device is pressed by external force, the insulating film bends due to the flexibility of the film, so that the conductive layers at both ends contact each other to play a role of conduction or disconnection. When the finger is released, the contact rebounds and the circuit is disconnected.

Membrane switches are widely used in the control systems of various electronic products and are favored for their simple structure, stable performance, easy use and low cost.

What is the disadvantage of membrane keyboard?

The main disadvantages of membrane keyboards include the following:

• Short service life: The service life of membrane keyboards is relatively short, generally around a few million keystrokes, while the service life of mechanical keyboards can reach tens of millions of times or even more.

• Low tactile feedback: Membrane keyboards have no separate moving parts and low tactile feedback, which makes it difficult to make mistakes.

• The keys feel poor: they may become oily after long-term use, affecting the appearance and user experience.

• Design structure limitations: The design structure of the membrane keyboard limits its service life. Since there is no mechanical device, the keys are easily worn after long-term use, causing the keys to become harder and affecting the comfort of use.

• Insufficient personalization: membrane keyboards are mostly produced on assembly lines, suitable for mass production, but not suitable for high-end customization, and relatively few personalized designs.

What is the difference between a switch and a membrane keyboard?

There are many differences between switches and membrane keyboards, as follows:

1. Basic principle

• Switch: An electronic component that can open a circuit, interrupt the current, or flow it to other circuits. The principle is to control the on and off of the current by closing and opening the contact.

• Membrane keyboard: A type of keyboard that sets multiple layers of plastic film inside the keyboard, prints conductive circuits and contacts on the film, and when the key on the keyboard is pressed, the keycap under the key will press the film, so that the conductive circuits and contacts on the upper and lower layers of the film contact, thereby realizing the conduction of the circuit and completing the input of the key signal.

2. Structural features

• Switch: The structure is relatively simple, usually composed of mechanical parts or electronic components such as contacts and metal dome. Common micro switches have a metal dome inside. When the switch is pressed, the dome deforms to make the contact conductive. After releasing, the dome returns to its original state and the contact is disconnected.

• Membrane keyboard: It is composed of multiple layers of film, keycaps, circuit boards, etc. Among them, the film is the core component, generally including the top insulating layer, the middle conductive layer and the bottom insulating layer. The key function is realized by printing circuits and contacts on different layers.

3. Hand feel feedback

• Switch: Different types of switches have obvious differences in hand feel. For example, the mechanical switch has a crisp and clear hand feel, the key stroke is relatively long, and there is an obvious sense of paragraph and feedback force when pressing. Users can clearly feel the triggering of the key.

• Membrane keyboard: The hand feel is relatively soft, the key stroke is short, the feedback force when pressing is not as obvious as the mechanical switch, there is a lack of clear sense of paragraph, and the overall hand feel is relatively gentle

4. Service life

• Switch: Switches with better quality, such as mechanical switches, usually have a longer service life and can withstand millions or even higher key operations.

• Membrane keyboard: The lifespan of a general membrane keyboard is relatively short, usually around 10 million times, and as the use time increases, the elasticity and conductivity of the membrane may decrease, leading to key failure and other problems

What is the lifespan of a membrane keyboard?

The service life of a membrane keyboard is generally between 1 and 5 years, and the specific lifespan depends on many factors, including frequency of use, use environment, and maintenance.

Factors affecting the lifespan of a membrane keyboard:

• Frequency of use: The higher the frequency of use, the shorter the lifespan of the membrane keyboard.

• Usage environment: Humid, high temperature, dusty and other environments will have an adverse effect on the service life of the membrane keyboard.

• Cleaning and maintenance: Regular cleaning and maintenance of the keyboard can extend its service life. Dust and other debris will affect the sensitivity and comfort of the keys.

Comparison of membrane keyboards with other types of keyboards:

• Mechanical keyboards: Due to the use of physical key structure, the durability is high and can usually be used for three to five years, or even longer.

• Membrane keyboards: Relatively fragile, with a service life of about two to three years. The key material and structure of the membrane keyboard make it have a short lifespan, usually between 1 and 5 years.

The “switch” in the membrane keyboard has the advantages of being light and portable, low cost, waterproof and dustproof, and has been widely used in electronic devices. At the same time, as a special electronic component, the membrane switch also plays an important role in the membrane keyboard.