A key device includes a bottom plate, a light guiding membrane switch, and a keycap. The light guiding membrane switch is disposed on the bottom plate and includes a lower membrane layer, an upper membrane layer, a light guiding spacing layer, a reflective layer, and an adhering layer. The upper membrane layer is disposed above the lower membrane layer and farer from the bottom plate than the lower membrane layer. The light guiding spacing layer is disposed between the lower membrane layer and the upper membrane layer and includes opposite upper and lower surfaces. The reflective layer is securely fastened on the upper surface. The adhering layer is adhered between the reflective layer and the upper membrane layer, and a position and a shape of the adhering layer correspond to a position and a shape of the reflective layer.

A method is for making an electronic device that includes a multilayer circuit board having a non-planar three-dimensional shape defining a membrane switch recess therein. The multilayer circuit board may include at least one liquid crystal polymer (LCP) layer, and at least one electrically conductive pattern layer thereon defining at least one membrane switch electrode adjacent the membrane switch recess to define a membrane switch. The electronic device may further include a compressible dielectric material filling the membrane switch recess. The electronic device may also include at least one spring member within the membrane switch recess.

A method is for making an electronic device that includes a multilayer circuit board having a non-planar three-dimensional shape defining a membrane switch recess therein. The multilayer circuit board may include at least one liquid crystal polymer (LCP) layer, and at least one electrically conductive pattern layer thereon defining at least one membrane switch electrode adjacent the membrane switch recess to define a membrane switch. The electronic device may further include a compressible dielectric material filling the membrane switch recess. The electronic device may also include at least one spring member within the membrane switch recess.

A keyboard includes a backlight module, a base plate, a membrane circuit disposed on the base plate, and a plurality of key structures disposed on the membrane circuit. The backlight module includes a light source, a reflective layer, a light guide layer, and a shielding layer. The light source is disposed corresponding to the light guide layer. The light guide layer is located between the shielding layer and the reflective layer. The light guide layer has a through-hole. The shielding layer and the reflective layer are in contact with each other in the through-hole of the light guide layer. The base plate is disposed on the shielding layer. The base plate has a positioning portion disposed corresponding to the through-hole of the light guide layer, which protrudes toward the reflective layer or the membrane circuit.

A keyboard includes a backlight module, a base plate, a membrane circuit disposed on the base plate, and a plurality of key structures disposed on the membrane circuit. The backlight module includes a light source, a reflective layer, a light guide layer, and a shielding layer. The light source is disposed corresponding to the light guide layer. The light guide layer is located between the shielding layer and the reflective layer. The light guide layer has a through-hole. The shielding layer and the reflective layer are in contact with each other in the through-hole of the light guide layer. The base plate is disposed on the shielding layer. The base plate has a positioning portion disposed corresponding to the through-hole of the light guide layer, which protrudes toward the reflective layer or the membrane circuit.

A key structure includes a membrane circuit board, an elastic element and a high impedance layer. The membrane circuit board includes a lower plate, an upper plate, a spacer plate and a circuit layer. The upper plate is located over the lower plate. The upper plate has an opening through the upper plate. The spacer plate is arranged between the lower plate and the upper plate. The circuit layer is arranged between the spacer plate and the upper plate. The elastic element is disposed on the membrane circuit board and substantially aligned with opening. The high impedance layer is disposed on a bottom surface of a bottom part of the elastic element and disposed within the opening of the upper plate. The high impedance layer is in contact with a part of the circuit layer.

A control device is provided. A membrane switch of the control device is specially designed. A cured ink member is formed on a surface the upper film layer facing the lower film layer or a surface of the lower film layer facing the upper film layer by using a UV printing process. Due to the ink member, a specified gap or distance between the upper film layer and the lower film layer can be maintained when they are not contacted with each other or when the membrane switch is not triggered.

A control device is provided. A membrane switch of the control device is specially designed. A cured ink member is formed on a surface the upper film layer facing the lower film layer or a surface of the lower film layer facing the upper film layer by using a UV printing process. Due to the ink member, a specified gap or distance between the upper film layer and the lower film layer can be maintained when they are not contacted with each other or when the membrane switch is not triggered.

A keyboard device includes a circuit substrate, a control unit and plural touch key structures. The control unit is installed on the circuit substrate. Each touch key structure includes a base plate, a keycap, a connecting element and a touch-sensitive circuit layer. The base plate is detachably installed on the circuit substrate. The keycap is located over the base plate. The connecting element is arranged between the base plate and the keycap. The keycap is movable upwardly or downwardly relative to the base plate through the connecting element. The touch-sensitive circuit layer is arranged between the base plate and the keycap, and electrically connected with the control unit. After a touch signal is received by the touch-sensitive circuit layer, the touch signal is transmitted to the control unit, and the touch signal is converted into an input signal by the control unit.

A keyboard device includes a circuit substrate, a control unit and plural touch key structures. The control unit is installed on the circuit substrate. Each touch key structure includes a base plate, a keycap, a connecting element and a touch-sensitive circuit layer. The base plate is detachably installed on the circuit substrate. The keycap is located over the base plate. The connecting element is arranged between the base plate and the keycap. The keycap is movable upwardly or downwardly relative to the base plate through the connecting element. The touch-sensitive circuit layer is arranged between the base plate and the keycap, and electrically connected with the control unit. After a touch signal is received by the touch-sensitive circuit layer, the touch signal is transmitted to the control unit, and the touch signal is converted into an input signal by the control unit.