Membrane switches can be structurally divided into two major categories: tactile and non-tactile. Non-tactile types typically come in two structures: flat non-tactile and raised button frame (with raised blind spots in some cases) non-tactile.

The non-tactile membrane switch does not require a specific feel, but it has high sensitivity requirements. It should conduct when lightly touched, but not short-circuit when the button is not pressed. Therefore, reasonable isolation points need to be added to the lower circuit key body. Early non-tactile membrane switches used colors to represent the position, shape, and size of the keys, allowing operators to identify the operation by visual perception. For ease of operation and improved accuracy, the panel was later designed with raised button borders or raised blind spots. In recent years, many flat non-tactile membrane switches have been changed to capacitive membrane switches.

There are many structural forms of tactile membrane switches, with the most classic ones being the convex bubble tactile type and the dome (pot chip) tactile type.

Common types of convex bubble tactile membrane switches include those with both the upper circuit and panel being convex, as well as those with only the panel being convex. For some ultra-thin structures, the upper circuit is removed, and the upper circuit contacts are directly printed on the panel. The convex bubbles of membrane switches are formed by heating and hydraulically pressing the mold, causing the key body to slightly bulge and protrude slightly above the panel, forming a three-dimensional membrane switch key. The material is selected to be PET, which has excellent toughness and heat shrinkage properties. The heat-pressed bubbles create a rebound force, making the tactile feel of convex bubble tactile membrane switches very good, and the electrical performance of pressing is sensitive. However, it is important to avoid long-term use in high-temperature environments, as high temperatures can weaken the tactile feel of the keys. Generally, convex bubble membrane switches choose to have both the upper circuit and panel being convex. When the upper circuit is not convex, consideration must be given to the position of the ventilation slot, where small holes are drilled in the upper circuit to serve as air vents. If necessary, reasonable isolation points are added to the contacts of the lower circuit to avoid the hidden dangers of short circuits and continuity issues. When the contacts are directly printed on the panel, consideration must be given to the degree of deformation of the panel after high-temperature aging. If the high-temperature baking time is too long, the deformation will be significant, causing great difficulties in assembling and pasting the membrane switch. If the high-temperature baking time is too short, the contacts on the panel will not have sufficient aging time, and the contacts are prone to wear, shortening the product's lifespan.

The tactile membrane switch with dome (pot chip) refers to a design where the dome is fixed on the lower circuit to form a pole as the upper circuit. When the dome is pressed, it connects with another pole of the lower circuit to form a loop. The buttons of the dome tactile membrane switch can be designed diversely, making the product more stable and reliable, while enhancing its decorative effect and achieving a perfect appearance. The panel can be designed as flat, convex spherical, or convex flat, and can be shaped in various forms such as circular, square, triangular, and irregular shapes. When the buttons are designed as flat or convex with button frames and blind spots, the surface adhesive layer should be thicker to provide sufficient space for the dome to move freely. If the tactile feel is not good, small shims can be added to the back of the panel buttons. The design of the dome fixing layer can be divided into two forms: punching at the corresponding key positions (with a hole diameter smaller than the dome) or bubbling. The punching design provides a crisper tactile feel and uniform force, while the bubbling design offers better overall sealing. The second structure of the dome tactile type refers to the dome directly added on the key position of the upper circuit to enhance the tactile feel. When there are a large number of buttons and the overall shape is small, with no space for wiring, the upper and lower circuit structure is adopted. However, this structure has slightly lower sensitivity, requiring a slightly greater pressing force and a slightly longer release time by the finger. Sometimes, there may be a phenomenon where the circuit is not connected despite the tactile feel of pressing and the sound of the dome being heard.

There are two types of structures for LEDs embedded in membrane switches: those with LED circuits and those with lower circuits on the same layer or different layers.

The structure where the LED circuit is on the same layer as the underlying circuit is relatively simple, but the LED window needs to be bubbled, otherwise, the LED light will lift the panel, and the LED is also prone to damage due to heavy pressure. Choosing 0603 LEDs with a shorter height but smaller solder pads makes soldering more difficult. The commonly used height for 0806 LEDs is 0.8mm, with larger solder pads, resulting in fewer cases of cold solder joint. The structure where the LED circuit is on a different layer from the underlying circuit is relatively complex, but the overall thickness of the membrane switch is thicker, and the LED window does not necessarily need to be bubbled. Membrane switches with LEDs often require an electrostatic shielding layer on the panel. Green and blue LEDs are easily damaged by static electricity, which is particularly severe in winter.

There are two types of waterproof structures. The waterproof structure is generally designed as a loop-shaped embedded structure. One structure is made of completely identical materials in two parts to form a finished product, with the circuit part embedded into the panel part to form a single product. This structure is commonly used, and waterproof glue is required for each layer of glue; the other structure uses materials of uniform thickness such as upper and lower circuits and isolation layers, and is made into a membrane switch frame structure with the panel. The circuit part is embedded inside to form a single unit. Waterproof glue can generally be 3M9495LE or 3MGTM920.

A light-guiding structure refers to the integration of a light-guiding sheet into a conventional membrane switch, utilizing side-lit LEDs to illuminate the buttons (EL cold light sheets can also be used). This design enables the membrane switch to be used at night and in low-light environments, enhancing its visual appeal. When crafting a light-guiding membrane switch, it is essential to ensure that there is no light leakage or cross-talk between the panel and the sides of the membrane switch. All double-sided adhesive should be black adhesive. The addition of the light-guiding sheet may weaken the tactile feel of the buttons. To compensate, shims can be added to the back of the button positions on the panel to enhance the tactile experience.

The folding structure is also considered for use when there are a large number of buttons and the overall shape is small, leaving no space for wiring. It is designed in the form of an upper and lower circuit structure. Special attention is paid to the folding process, which must be carried out under heat. The impact of increased service life on the folding points must be taken into account.

Each structure has its own characteristics. We choose the most suitable structure at the beginning of design to produce high-quality products and serve our vast number of users.