JP2007194092A - Membrane sheet and switching device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a switching device which can illuminate each surface of a plurality of key-tops easily with a desired color and desired brightness, also can illuminate each key-top with an individual different color as well as can change color, and can turn light on and off for each key-top individually. <P>SOLUTION: This switching device comprises a base substrate 2 having a fixed contact electrode 1 on its main surface, a metal dome 3 which is arranged at a position corresponding to the fixed contact electrode 1, and a membrane sheet 9 which is disposed on the metal dome 3. The membrane sheet 9 comprises a membrane base substrate 9a made of insulating material, an LED 10 disposed on the membrane base substrate 9a, a circuit pattern 9b which is disposed on the membrane base substrate 9a for power supplying to the LED 10, and a key-top 11 made of transmissive material which is disposed on the membrane base substrate 9a as to cover the LED 10. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a switch device used as an input key switch or the like in various electronic devices such as a mobile phone device, and also relates to a membrane sheet used in the configuration of such a switch device.

  2. Description of the Related Art Conventionally, in an electronic device such as a mobile phone device, as described in Patent Document 1, a switch device having a click feeling such as a so-called membrane switch or a metal dome switch (disc spring switch) is used as an input key switch. in use. As a switch having such a click feeling, the metal dome switch has a contact circuit base substrate 102 on which a contact electrode 101 is formed, as shown in FIG. 4, and the metal dome is formed on the contact circuit base substrate 102. (Disc spring) 103 and a metal dome presser sheet 104, and further, a key mat layer 105 is provided on the metal dome presser sheet 104.

  An internal wiring circuit 106 connected to the contact electrode 101 is formed on the contact circuit base substrate 102. The contact electrodes 101 and the internal wiring circuit 106 are connected by vias (Via) or through holes (TH) 107. The contact electrode 101 is formed on the surface of the contact circuit base substrate 102.

  The metal dome 103 is formed in a dome shape (dish shape) with a thin metal plate, and is placed on the contact electrode 101. The metal dome 103 is fixed to the upper surface of the contact circuit base substrate 102 while being covered with a metal dome holding sheet 104. The metal dome holding sheet 104 is bonded to the surface of the contact circuit base substrate 102 and the upper surface of the metal dome 103 by an adhesive layer 108.

  The key mat layer 105 includes a base rubber 109 installed on the metal dome presser sheet 104 and a key top 111 bonded to the base rubber 109 with an adhesive 110. The base rubber 109 is formed in a sheet shape from a synthetic resin material, and has a plunger 112 on the lower surface facing the metal dome holding sheet 104. The plunger 112 is formed as a protrusion protruding downward from the bottom surface of the base rubber 109. The key top 111 is a portion serving as a push button, and is formed of a synthetic resin material. An upper surface portion of the key top 111 that is pressed is a key top decoration portion 113 on which characters, symbols, and the like are printed.

  In this switch device, when the upper surface portion of the key top 111 is pressed, the key top 111 moves to the metal dome 103 side, and the base rubber 109 is pressed and deformed. When the base rubber 109 is pressed and deformed by the key top 111, the plunger 112 presses the central portion of the upper surface of the metal dome 103 through the metal dome holding sheet 104. Then, the metal dome 103 is elastically displaced toward the contact circuit base substrate 102 and comes into contact with the contact electrode 101. When the metal dome 103 comes into contact with the contact electrode 101, the separated patterns in the contact electrode 101 are brought into conduction, and a switch operation is performed.

  As such a switch device, as shown in FIG. 5, a device including a light emitting element (LED) 114 for illuminating the key top 111 has been proposed. In this switch device, the light emitting element 114 is installed on the metal dome holding sheet 104 and arranged at a position between the plurality of key tops 111. Therefore, it is necessary to use a light guide so that the illumination light from the light emitting element 114 is guided to the key top decoration portion 113 via the key top 111. This light guide is composed of a light guide plate made of a light-transmitting resin material or the like and a base rubber 109.

JP 2004-031154 A

  By the way, in the conventional switch device as described above, the illumination light emitted from the light emitting element 114 is dispersedly reflected by the metal dome holding sheet 104 and transmitted between the base rubber 109, the adhesive 110 and the key top 111. The key top decoration part 113 is reached, and the key top decoration part 113 is illuminated from the back side.

  As described above, in the conventional switch device, the illumination light emitted from the light emitting element 114 passes through various members and reaches the key top decoration portion 113. Therefore, in order for the key top decoration unit 113 to be illuminated with a desired color and desired brightness, the transmittance and color of each member through which the illumination light from the light emitting element 114 is transmitted are appropriately set. It is difficult to design and manufacture.

  Further, in the conventional switch device, each key top 111 and each light emitting element 114 do not correspond one-to-one, each key top 111 is illuminated by a plurality of light emitting elements 114, and each light emitting element 114 is A plurality of key tops 111 are illuminated.

  Therefore, in the conventional switch device, it is difficult to individually illuminate each keytop 111 with illumination light of a different color, and it is also possible to individually switch the illumination light color and lighting on / off. There wasn't. In order to individually illuminate each key top 111 with illumination light of a different color, it is conceivable to install a color filter for each key top 111, but the configuration is complicated, and the color of the illumination light is switched. It is not possible.

  Note that although a switch device using an EL panel instead of an LED can be considered as the light emitting element 114, even in a switch device using an EL panel, it is not possible to individually illuminate each keytop 111 with illumination light of different colors. It is difficult, and the color of the illumination light and switching between lighting and extinguishing cannot be performed individually. Further, the EL panel has a problem regarding durability and light emission luminance, and there is also a problem that noise is easily generated unless an inverter control circuit is used.

  Therefore, the present invention has been proposed in view of the above-described circumstances, and in a switch device having a plurality of key tops, the surface portion (key top decoration portion) of each key top has a desired color and a desired color. It is possible to easily illuminate by brightness, and to easily illuminate each keytop with illumination light of a different color, or to individually switch the color of illumination light and turn on and off individually It is another object of the present invention to provide a membrane sheet and a switch device configured using the membrane sheet.

  In order to solve the above-mentioned problems, the present invention has any one of the following configurations.

[Configuration 1]
The membrane sheet according to the present invention is made of an insulating material and is a membrane base material that becomes a movable part in the switch device, a light emitting element installed on the membrane base material, It has a circuit pattern and a key top made of a translucent material that covers a light emitting element and is placed on a membrane base material.

[Configuration 2]
The membrane sheet according to the present invention is characterized in that, in the membrane sheet having Configuration 1, a plunger member is installed at a position corresponding to the light emitting element on the lower surface portion of the membrane base material.

[Configuration 3]
The membrane sheet according to the present invention is characterized in that in the membrane sheet having Configuration 1 or Configuration 2, the membrane base material has a plurality of openings formed at positions around the light emitting element. Is.

[Configuration 4]
The membrane sheet according to the present invention is a membrane sheet having any one of Configurations 1 to 3, wherein the light-emitting element is sealed with a light-transmitting resin material.

[Configuration 5]
A switch device according to the present invention is installed on a base substrate having a fixed contact electrode formed on one main surface, a metal dome serving as a movable contact disposed at a position corresponding to the fixed contact electrode, and the metal dome. And a membrane sheet having any one of configurations 1 to 4.

  Since the membrane sheet according to the present invention has the configuration 1, the light emitting element and the key top correspond one-to-one. Therefore, in the switch device having a plurality of key tops, the surface portion of each key top (key top) It is easy to illuminate the decoration part) with a desired color and desired brightness, and each key top is individually illuminated with illumination light of a different color, or the color of the illumination light, lighting and turning off individually Can be easily switched.

  In addition, when an LED is used as a light emitting element, for example, each keytop can be illuminated with high brightness compared to illumination using an EL panel, there is no possibility of noise generation, and sufficient durability is achieved. Can be realized.

  Since the switch device using this membrane sheet can individually switch the color of illumination light and turn on and off for each key top, a predetermined key top is used for the purpose of so-called “operation guide” and “typing practice”. This can be indicated by illumination.

  Moreover, since the switch apparatus using this membrane sheet does not require a separate light guide, it can be thinned.

  Since the membrane member according to the present invention has the configuration 2, since the plunger member has a position corresponding to the light emitting element, a reliable switch operation can be realized.

  Since the membrane sheet according to the present invention has the configuration 3 and has a plurality of openings at positions around the light emitting element, movement of the membrane sheet in the surface direction (vertical direction) at the place where the light emitting element is installed Can be done smoothly.

  Since the membrane sheet according to the present invention has the configuration 4, since the light emitting element is sealed with a light-transmitting resin material, the light emitting element is protected, and the ESD (Electric Static Discharge :) of the light emitting element is protected. Electrostatic discharge) breakdown characteristics can be improved.

  Since the switch device according to the present invention has the configuration 5, the membrane sheet has any one of the configurations 1 to 4, so that the surface portion (key top decoration portion) of each key top has a desired color and a desired It is easy to illuminate with the brightness of each key, and it is easy to individually illuminate each key top with illumination light of a different color, or to individually switch the color of illumination light, lighting and extinguishing.

  In addition, when an LED is used as a light emitting element, for example, each keytop can be illuminated with high brightness compared to illumination using an EL panel, there is no possibility of noise generation, and sufficient durability is achieved. Can be realized.

  In this switch device, it is possible to individually switch the color of illumination light and turn on and off for each key top. For the purpose of so-called "operation guide" and "typing practice", a predetermined key top is indicated by illumination. It becomes possible.

  In addition, since this switch device does not require a separate light guide, it can be reduced in thickness.

  That is, according to the present invention, in a switch device having a plurality of key tops, it is possible to easily illuminate the surface portion (key top decoration portion) of each key top with a desired color and desired brightness. It is possible to provide a membrane sheet that allows each keytop to be individually illuminated with illumination light of a different color, or to easily switch the color of illumination light or switching on and off individually.

  Further, according to the present invention, by using this membrane sheet, it is easy to illuminate the surface portion (key top decorative portion) of each key top with a desired color and desired brightness. It is possible to provide a switch device that can easily illuminate the illumination light of different colors with respect to the top or easily switch the illumination light color, lighting and extinction individually.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

[First Embodiment]
(A) in FIG. 1 is a plan view showing the configuration of the switch device according to the present invention, and (b) in FIG. 1 is a cross-sectional view showing the configuration of this switch device.

  As described below, the switch device according to the present invention includes the membrane sheet according to the present invention. As shown in FIG. 1B, the switch device has a contact circuit base substrate 2 on which contact electrodes 1 are formed, and a metal dome (movable contact) on the contact circuit base substrate 2. And a key mat layer 5 including a membrane sheet 9 according to the present invention.

  An internal wiring circuit (not shown) connected to the contact electrode 1 is formed on the contact circuit base substrate 2. The contact electrode 1 and the internal wiring circuit are connected by a via (not shown) or a through hole (TH). The contact electrode 1 is formed on the surface of the contact circuit base substrate 2.

  The metal dome 3 is formed in a dome shape (dish shape) by a thin metal plate, and is placed on the contact electrode 1. The metal dome 3 is fixed to the upper surface of the contact circuit base substrate 2 while being covered with a metal dome holding sheet 4. The metal dome holding sheet 4 is made of an insulating material such as a PET (Polyethyleneterephthalate) base material, and is bonded to the surface of the contact circuit base base material 2 and the upper surface of the metal dome 3 by an adhesive layer 8.

  The key mat layer 5 is constituted by a membrane sheet 9 installed on the metal dome holding sheet 4 and has a key top 11. The membrane sheet 9 is made of an insulating material such as a flat sheet-like PET and has a membrane base material 9a serving as a movable part. On the membrane substrate 9a, an LED 10 serving as a light emitting element is installed. The LED 10 is installed corresponding to each metal dome 3. The LED 10 is mounted on a mounting land portion formed by screen-printing a conductive adhesive on the membrane substrate 9a. A circuit pattern 9b for supplying power to the LED 10 is formed on the membrane substrate 9a. The circuit pattern 9b is formed by screen printing. A protective layer 9c is formed on the circuit pattern 9b. The protective layer 9c protects the circuit pattern 9b, and is formed by attaching an insulating film or printing an insulating material.

  And LED10 is sealed with the resin material 12 which has translucency. The resin material 12 protects the LED 10 and improves the ESD (Electric Static Discharge) destruction characteristics of the LED 10.

  On the resin material 12 that seals the LED 10, a key top 11 is installed via a base rubber 14. The base rubber 14 and the key top 11 are made of a synthetic resin material having translucency, and are installed on the membrane base material 9 a so as to cover the LED 10. The key top 11 is a portion that becomes a push button, and the upper surface portion to be pressed is a key top decoration portion 13 on which characters, symbols, and the like are printed, as shown in FIG. Yes.

  And the plunger member 7 is installed in the position corresponding to LED10 of the lower surface part of the membrane base material 9a. That is, the membrane base material 9 a has a concave portion (embossed portion) 6 at a position that is substantially the center of the metal dome 3 when placed on the metal dome 3. The recess 6 is a protrusion on the metal dome 3 side. The recess 6 is formed by press molding (so-called embossing or drawing). The depth of the concave portion 6 depends on the specification of the metal dome 3 to be combined, but normally it is preferably about 0.2 mm to 0.8 mm. A plunger member 7 is disposed in the recess 6. The plunger member 7 is formed by filling a concave portion 6 with a fluid material such as an epoxy resin or an ultraviolet curable resin (UV resin). As a material forming the plunger member 7, most epoxy resins can be adopted.

  In this switch device, when the upper surface portion of the key top 11 is pressed, the key top 11 moves to the metal dome 3 side, and the membrane sheet 9 is pressed and deformed. At this time, the pressing force by pressing the key top 11 is transmitted from the key top 11 to the membrane sheet 9 through the base rubber 14, the resin material 12 sealing the LED 10, and the LED 10. The membrane sheet 9 is pressed and deformed in this manner, thereby pressing the center portion of the upper surface of the metal dome 3 via the plunger member 7 and the metal dome holding sheet 4. Then, the metal dome 3 is elastically displaced toward the contact circuit base substrate 2 and comes into contact with the contact electrode 1. In this way, when the metal dome 3 comes into contact with the contact electrode 1, the separated patterns in the contact electrode 1 are brought into conduction, and a switch operation is performed. In this switch device, since the plunger member 7 is provided, a reliable switch operation is realized.

  Further, in this switch device, the illumination light emitted from the LED 10 is transmitted through the resin material 12, the base rubber 14, and the key top 11 sealing the LED 10, and the key top decorative portion 13 is seen from the back side. Illuminate. In this switch device, since the LEDs 10 and the key tops 11 correspond one-to-one, it is easy to illuminate the key top decorations 13 of each key top 11 with a desired color and desired brightness. In addition, it is easy to illuminate each key top 11 individually with illumination light of a different color, or to individually switch the color of illumination light and the on / off of the illumination light. Therefore, in this switch device, it is possible to instruct the predetermined key top 11 by the presence or absence of illumination and the color for the purpose of so-called “operation guide” and “typing practice”.

  In addition, in this switch device, each keytop 11 can be illuminated with high brightness compared to illumination using an EL panel, and there is no risk of noise generation and sufficient durability is achieved. ing. Furthermore, in this switch device, since a separate light guide is unnecessary, the thickness can be reduced. And this switch apparatus is applicable to almost all input switches, such as a mobile phone, a game machine, and an electrical appliance.

  In addition, the membrane sheet 9 which concerns on this invention can be produced according to the following processes.

(1) Membrane circuit processing First, a printing type conductive ink is screen-printed on a membrane substrate 9a made of PET or the like to form a circuit pattern 9b. Thereafter, the protective layer 9c is formed by laminating or screen printing. Here, double-sided circuit printing may be performed through a through hole depending on the outer shape restriction or the like.

(2) Emposing The embossing is performed on the membrane substrate 9a to form the recess 6 for installing the plunger member 7. In addition, you may perform this empos processing before the membrane circuit processing of (1).

(3) Installation of plunger member (resin filling)
A resin material having a sufficient hardness such as an epoxy resin is filled in the concave portion 6 by dispensing or screen printing and cured to form the plunger member 7. Such resin filling is performed prior to the conductive adhesive screen printing in the mounting step (4) below, and after mounting the components, the resin material is cured, and then the conductive adhesive is dispensed. By doing so, more reliable mounting becomes possible.

(4) Component mounting A conductive adhesive is screen-printed around the recess 6 on the membrane substrate 9a to form a mounting land portion, the LED 10 is mounted, and then the conductive adhesive is cured. Thereafter, the resin material 12 for sealing the LED 10 is dispensed and cured well. At this time, if the entire surface of the LED 10 is coated, an excellent effect on the ESD destruction characteristics can be obtained.

[Second Embodiment]
(A) in FIG. 2 is a plan view showing the configuration of the membrane sheet according to the second embodiment of the present invention, and (b) in FIG. 2 is a cross-sectional view showing the configuration of this membrane sheet. is there.

  As shown in FIG. 2, the membrane sheet 9 according to the present invention may be configured by forming a plurality of openings 15 at positions around the LEDs 10 of the membrane substrate 9 a. That is, in the membrane sheet 9, a plurality of openings 15 are formed so as to surround the LED 10. The opening 15 can be formed by pressing (punching).

  Since the plurality of openings 15 are formed in this way, the elastic force in the surface direction (vertical direction) of the membrane sheet 9 at the place where the LED 10 is installed is weakened, and the metal dome is pressed by the pressing operation on the key top 11. The movement to the 3 side is performed smoothly. In this case, the characteristics of the metal dome 3 are directly transmitted to the key top 11, and a good switch operation feeling can be realized.

[Third Embodiment]
FIG. 3 is a cross-sectional view showing the configuration of the switch device according to the third embodiment of the present invention.

  The switch device according to the present invention may be configured by integrally forming the key top 11 and the base rubber 14 as shown in FIG. That is, in this case, the key top 11 is directly attached to the membrane sheet 9 while being covered with the LED 10.

  Also in this case, when the upper surface portion of the key top 11 is pressed, this pressing force is transmitted from the key top 11 to the membrane sheet 9 through the resin material 12 and the LED 10 sealing the LED 10. . The membrane sheet 9 is pressed and deformed in this manner, thereby pressing the center portion of the upper surface of the metal dome 3 via the plunger member 7 and the metal dome holding sheet 4. Then, the metal dome 3 is elastically displaced toward the contact circuit base substrate 2 and comes into contact with the contact electrode 1 to perform a switch operation. Moreover, in this switch device, the illumination light emitted from the LED 10 is transmitted through the resin material 12 and the key top 11 sealing the LED 10 to illuminate the key top decorative portion 13 from the back side.

  The membrane sheet according to the present invention is not limited to the metal dome switch in each embodiment described above, and this membrane sheet is installed on an FPC circuit (polyimide-based copper foil etching circuit) without using a metal dome. The present invention can also be applied to the switch device having the above configuration.

(A) is a top view which shows the structure of the switch apparatus based on this invention, (b) is sectional drawing which shows the structure of this switch apparatus. (A) is a top view which shows the structure in 2nd Embodiment of the membrane sheet which concerns on this invention, (b) is sectional drawing which shows the structure of this membrane sheet. It is sectional drawing which shows the structure in 3rd Embodiment of the switch apparatus which concerns on this invention. It is sectional drawing which shows the structure of the conventional switch apparatus. It is a top view which shows the installation position of the light emitting element in the conventional switch apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Contact electrode 2 Contact circuit base base material 3 Metal dome 4 Metal dome holding sheet 5 Key mat layer 6 Recess 7 Plunger member 8 Adhesive layer 9 Membrane sheet 9a Membrane base material 9b Circuit pattern 14 Base rubber 15 Opening 10 LED
11 Key top 13 Key top decoration

Claims (5)

A membrane base material made of an insulating material and serving as a movable part in the switch device;
A light emitting device installed on the membrane substrate;
A circuit pattern formed on the membrane substrate for supplying power to the light emitting element;
A membrane sheet comprising: a key top made of a translucent material that covers the light emitting element and is placed on the membrane base material. The membrane sheet according to claim 1, wherein a plunger member is installed at a position corresponding to the light emitting element on the lower surface of the membrane base material. The membrane sheet according to claim 1, wherein a plurality of openings are formed in the membrane base material at positions around the light emitting element. The membrane sheet according to any one of claims 1 to 3, wherein the light-emitting element is sealed with a resin material having translucency. A base substrate having a fixed contact electrode formed on one main surface;
A metal dome serving as a movable contact disposed at a position corresponding to the fixed contact electrode;
A switch device comprising: the membrane sheet according to any one of claims 1 to 4 installed on the metal dome.

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