JP7836066B2 - Capacitive touch switch, method for manufacturing a capacitive touch switch - Google Patents

Description

This invention relates to a capacitive touch switch that detects touch by a change in capacitance when a person touches or brings their finger close to it, and to a method for manufacturing this capacitive touch switch.

In recent years, there has been a growing demand for touch switches, including touch panels for liquid crystal displays, touch switches, and touchpads. One type of touch switch is the capacitive switch. A touch switch utilizing capacitive coupling defines a touch electrode (switch electrode) as the switch, and detects the on/off state of the switch by detecting changes in capacitance when a finger or hand approaches the touch electrode.

In such capacitive touch switches, it is common practice to provide a ground section (ground pattern, GND electrode) on the substrate film by printing in order to reduce noise and stabilize the signal level, and to provide a shielding section on the substrate film by printing in order to enable high-speed transmission of high-frequency signals and to counteract noise. When constructing a multilayer (e.g., two-layer) touch switch, a configuration is employed in which the lands (circuit portions) of the upper layer and the lands of the lower layer are connected at multiple points via through-holes (holes drilled in the substrate with copper plating on the inner walls) (for example, see Patent Document 1 below).

International Publication No. 2019/065064

However, if a multi-layer (e.g., two-layer) touch switch configuration requires through-holes, then high-precision through-hole machining is required, and printing is necessary for each substrate constituting each layer, leading to an increase in the number of printing operations.

After extensive research, the inventors have devised and realized a multi-layer capacitive touch switch and a method for manufacturing it that eliminates the need for through-holes while also reducing the number of printing processes required.

In other words, the capacitive touch switch according to the present invention is a touch switch in which at least touch electrodes are provided on a thin film substrate by printing, comprising a single substrate film in which one side is set as a printed surface and the other side is set as a non-printed surface, wherein at least touch electrodes are provided on the printed surface of a first region of the substrate film bounded by a predetermined first fold line, and at least a ground portion or a shield portion is provided on the printed surface of a second region adjacent to the first region across the first fold line by printing, and the non-printed surface of the first region and the non-printed surface of the second region are bonded together in an outward-folded state in which they face each other along the first fold line so that the printed surfaces of the first region and the printed surfaces of the second region do not face each other.

With the multilayer capacitive touch switch according to the present invention, through-holes are unnecessary, and at least the touch electrodes and ground portion or shield portion can be provided by a common printing process on a printed surface set on only one side of a single base film. Therefore, the number of printing processes can be reduced compared to a multilayer touch switch in which each layer of base film is printed separately. Furthermore, the multilayer capacitive touch switch according to the present invention employs a two-layer substrate structure formed by folding a single base film, and the touch electrodes and ground portion or shield portion are printed only on the same side (printed surface) of the base film in its unfolded state before folding. The outward-fold state is maintained by bonding the non-printed surfaces facing inward together when the switch is folded along a first fold line so that the printed surfaces of the first and second regions face outward from each other (outward-fold state). Therefore, compared to a configuration in which the printed surfaces of the first and second regions face inward from each other (inward-fold state), the distance between the printed surfaces of the first and second regions can be increased by at least twice the thickness dimension of the base film. As a result, when a self-capacitive capacitive touch switch is configured, the distance between the touch electrode on the first printed surface and the ground or shield on the second printed surface can be increased compared to the inward-bending configuration. Therefore, if the ground is provided on the second printed surface, it is possible to prevent or suppress the problem where parasitic capacitance increases and signal strength decreases as the ground is closer to the touch electrode. If the shield is provided on the second printed surface, the shielding effect can be improved.

Furthermore, if a configuration is adopted in which the printed surfaces of the first and second regions are folded inward (inward-folded state), it becomes necessary to interpose a dedicated film or other separate part as a spacer between the printed surfaces of the first and second regions to prevent short circuits. Compared to such an inward-folded configuration, the capacitive touch switch according to the present invention, which employs an outward-folded configuration, allows for a distance between the printed surfaces of the first and second regions equal to the thickness of the base film, eliminating the need for a dedicated spacer and enabling a reduction in the number of parts and further simplification of the structure.

As a specific example of a capacitive touch switch having only the basic configuration of the present invention , one can be cited in which the only fold line set on the base film is a first fold line, and a ground portion or shield portion is provided on the printed surface of the second region by printing. In this case, it becomes a two-layer substrate structure type capacitive touch switch having a touch electrode (sensor layer) provided on the printed surface of the first region by printing and a ground portion (ground layer) or shield portion (shield layer) provided on the printed surface of the second region by printing in layers. In such a two-layer substrate structure type capacitive touch switch, the ground layer that performs the ground function also provides a shielding effect, and the shield layer that performs the shielding function can also function as a ground.

Furthermore , the capacitive touch switch according to the present invention is of the three-layer substrate structure type, one of which is a substrate film having, in addition to the basic configuration described above, a third region adjacent to the second region with a second fold line in between, that is, the first region and the second region are adjacent with a first fold line in between, and the second region and the third region are adjacent with a second fold line in between, and a shield portion or ground portion is provided on the printed surface of the third region by printing, and the second region, the first region and the third region are arranged in this order in the stacking direction in an outward folded state with the printed surfaces of the second region and the third region not facing each other along the second fold line, and the portions of the first region and the third region that face each other are bonded together. In such a configuration, if a ground portion is provided on the printed surface of the second region by printing, a shield portion is provided on the printed surface of the third region by printing, and in the stacked state, the ground portion provided on the printed surface of the second region functions as a ground layer, and the shield portion provided on the printed surface of the third region functions as a shield layer. On the other hand, if a shield portion is provided on the printed surface of the second region by printing, a ground portion is provided on the printed surface of the third region by printing. In the laminated state, the shield portion provided on the printed surface of the second region functions as a shield layer, and the ground portion provided on the printed surface of the third region functions as a ground layer.

Furthermore, another three-layer substrate structure type capacitive touch switch of the present invention is one in which the substrate film has a third region adjacent to the first region with a second fold line in between, that is, the first region and the second region are adjacent with a first fold line in between, and the first region and the third region are adjacent with a second fold line in between, and a shield portion or ground portion is provided on the printed surface of the third region by printing, and the second region, the first region and the third region are arranged in this order in the stacking direction when folded inward along the second fold line so that the printed surfaces of the second region and the third region face each other, and the portions of the first region and the third region that face each other are bonded together. In such a configuration, if a ground portion is provided on the printed surface of the second region by printing, a shield portion is provided on the printed surface of the third region by printing, and in the stacked state, the ground portion provided on the printed surface of the second region functions as a ground layer, and the shield portion provided on the printed surface of the third region functions as a shield layer. On the other hand, if a shield portion is provided on the printed surface of the second region by printing, a ground portion is provided on the printed surface of the third region by printing. In the laminated state, the shield portion provided on the printed surface of the second region functions as a shield layer, and the ground portion provided on the printed surface of the third region functions as a ground layer.

Furthermore, if the capacitive touch switch according to the present invention employs a configuration in which an adhesive layer is formed between the non-printed surfaces of the first and second regions facing each other in the outward-folded state, the adhesive layer can ensure a good outward-folded state. Moreover, by changing the thickness of the adhesive layer, the distance between the printed surface of the first region and the printed surface of the second region can be adjusted. This not only eliminates the need for the spacer described above, but also contributes to increasing the distance between the printed surfaces of the first and second regions.

The capacitive touch switch according to the present invention includes an embodiment in which a terminal portion is formed in at least a first region. In this case, it is preferable that the terminal portion has a ground portion provided by a printing process.

Furthermore, the method for manufacturing a capacitive touch switch according to the present invention is a method for manufacturing a capacitive touch switch using a single thin-film substrate, comprising a printing step of printing at least touch electrodes and ground portions only on one side of the single substrate film, which is the printed surface ; forming adjacent first and second regions of the single substrate film with a predetermined first fold line as the boundary, and forming a third region adjacent to the second region with a predetermined second fold line as the boundary, and folding outwards along the first fold line so that the printed surfaces of the first and second regions do not face each other , and along the second fold line The manufacturing process is characterized by either folding the second, first, and third regions in an outward-fold state so that the printed surfaces of the second and third regions do not face each other, arranging them in this order in the stacking direction, and then bonding the non-printed surfaces that face each other , or folding the second, first, and third regions in an inward-fold state so that the printed surfaces of the second and third regions face each other along the second fold line, arranging them in this order in the stacking direction, and then bonding the non-printed surfaces that face each other between the first and second regions and the parts of the first and third regions that face each other .

According to this method for manufacturing a capacitive touch switch, the number of printing steps can be reduced, and through-hole processing is unnecessary. Therefore, it is possible to manufacture a capacitive touch switch with a multilayer substrate structure capable of detecting when a finger or hand approaches its touch electrode, using a relatively simple manufacturing method.

According to the present invention, by adopting a novel and useful technical concept never before conceived—where touch electrodes and the like are printed onto the printed surface of a single substrate film, and the printed surfaces of at least two adjacent regions (sensor layer and ground layer or shield layer) facing outwards across a first fold line are arranged in an outward-bent state to realize a multilayer substrate structure—it is possible to achieve a simple configuration that does not require through-holes, reduces the number of printing processes, and, based on the outward-bent configuration, exhibits the aforementioned unique effects that cannot be achieved with an inward-bent configuration, thereby providing a highly versatile capacitive touch switch and its manufacturing method that can be used in various applications.

A front view of a capacitive touch switch according to the first embodiment of the present invention. View taken in the direction of arrow a in Figure 1. This embodiment shows a front view of the base film in its unfolded state (before folding). Manufacturing flowcharts for each embodiment of the present invention of capacitive touch switches. A front view of a capacitive touch switch according to a second embodiment of the present invention. View taken in the direction of arrow a in Figure 5. View taken in the direction of arrow b in Figure 5. A front view of the substrate film in the unfolded state in the same embodiment. A front view of a capacitive touch switch according to a third embodiment of the present invention. View taken in the direction of arrow a in Figure 9. View taken in the direction of arrow b in Figure 9. A front view of the substrate film in the unfolded state in the same embodiment. Front view of a capacitive touch switch according to a fourth embodiment of the present invention. View taken in the direction of arrow a in Figure 13. View taken in the direction of arrow b in Figure 13. A front view of the substrate film in the unfolded state in the same embodiment.

One embodiment of the present invention will be described below with reference to the drawings.

<First Embodiment>
The capacitive touch switch X according to this embodiment is characterized by a two-layer structure formed by folding and laminating a single base film 1 (PET base film), as shown in Figures 1 to 3. Figure 1 is a front view of the capacitive touch switch X, Figure 2 is a view in direction a (side view) of Figure 1, and Figure 3 is a front view of the capacitive touch switch X (capacitive touch switch X with the base film 1 unfolded) at the completion of the printing process described later. Note that in Figure 2, the thickness is exaggerated to be thicker than the actual thickness for illustrative purposes.

In this embodiment, a flexible printed circuit board (FPC) with a predetermined thickness (e.g., approximately 100 μm) and high transparency is used as the base film 1 for circuit printing. One side of the single base film 1, in its unfolded state before folding, is set as the printing surface 2 (conductive surface), and the other side is set as the non-printing surface 3 (non-conductive surface). The touch electrode T, circuit P (power supply line), and ground section G are printed on the printing surface 2A of the first region A (the relatively lower region in Figure 3), which is one area bounded by the first fold line 4, the only fold line of the single base film 1 in its unfolded state. The ground section G and circuit P (power supply line) are printed on the printing surface 2B of the second region B (the relatively upper region in Figure 3), which is the other area bounded by the first fold line 4 (printing process S1, see Figure 4). In this embodiment, screen printing is used as the printing method in printing process S1.

In this embodiment, the touch electrodes T are formed using, for example, PEDOT (polyethylenedioxythiophene) or ITO (indium tin oxide) by the printing process S1, and the circuit P (power supply line) and ground portion G can be formed using, for example, silver paste. As shown in Figure 3, a plurality of touch electrodes T (four in the illustrated example) are provided at a predetermined pitch in the longitudinal direction of the first region A, and the ground portion G is provided in a frame shape surrounding the touch electrodes T arranged at a predetermined pitch in the first region A, and is provided in a mesh shape in almost the entire area of the second region B, excluding the area surrounded by a circle (four circles in the illustrated example) that is slightly larger than each touch electrode T and the peripheral edge. Therefore, in the state after the bonding process S2, the touch electrodes T and the ground portion G do not overlap in a plan view, while the circuit P (power supply line) and the ground portion G partially overlap. Furthermore, while placing a ground section G around the touch electrode T can prevent malfunctions caused by electromagnetic field noise, there is a possibility that touch sensitivity may decrease due to parasitic capacitance from the ground section G. Therefore, it is preferable to make the ground section G a mesh shape to reduce parasitic capacitance (see Figures 1 and 3). Providing a ground section G can reduce noise and stabilize the signal level.

In this embodiment, since the circuit P (power supply line) and the ground section G are made of the same material, these circuits P (power supply line) and ground section G can be printed simultaneously on the printing surface 2A of the first region A and the printing surface 2B of the second region B of a single base film 1. Furthermore, in this embodiment, circuits P (power supply lines) connecting the circuits P (power supply lines) and ground sections G of each region (first region A, second region B) are also printed in the printing process S1 at a position spanning the first region A and the second region B (see Figure 3).

Furthermore, in this embodiment, the printing process S1 is configured to print a resist (insulating layer) using resist ink at appropriate locations on the printing surface 2 (locations where the touch electrode T, circuit P, and ground G are not printed). The resist serves both to protect and insulate the silver from PEDOT or ITO, and is formed using, for example, a highly transparent material that does not adversely affect the light transmittance of the touch electrode T.

In this embodiment, slits 5 (small holes shown in Figure 3) are formed at predetermined locations along the first fold line 4 of the base film 1, facilitating the folding process along the first fold line 4. In this embodiment, the slits 5 are formed at positions that sandwich the two circuits P (power supply lines) connecting the circuits P (power supply lines) and ground sections G in each region (first region A, second region B) (see Figure 3).

The base film 1 has a flexible portion 60 with a terminal portion 6 at its tip, which functions as a terminal, located on the edge furthest from the first fold line 4 in the first region A. Circuits P (power supply lines) and ground portions G are also provided at predetermined locations on the flexible portion 60, including the terminal portion 6, through printing in the printing process S1. In particular, carbon is provided on the terminal portion 6 through printing in the printing process S1 to ensure its conductivity. By providing a reinforcing plate 61 on the terminal portion 6, it is also possible to adjust its thickness to allow insertion into a connector.

After performing a printing process on the base film 1 (after the printing process S1), the capacitive touch switch X according to this embodiment can be manufactured by performing a process of folding and bonding the base film 1 along the first folding line 4 (bonding process S2). In the bonding process S2, as shown in Figure 2, the printed surface 2A of the first region A and the printed surface 2B of the second region B are folded outwards (outward bending), and the non-printed surface 3A of the first region A and the non-printed surface 3B of the second region B are bonded together via the adhesive 7 so that they face each other. The process of applying the adhesive 7 to the non-printed surface 3 can be performed simultaneously with the printing process or with a time delay. In this embodiment, silicone OCA (Optical Clear Adhesive) is used as the adhesive 7. It is also possible to use glue other than silicone OCA, double-sided tape, etc. as the adhesive 7. The thickness dimension of the capacitive touch switch X can also be adjusted by adjusting the thickness of the adhesive layer on which the adhesive 7 is placed. In Figure 2, the printed layers 20 (touch electrodes, circuits, ground area, resist) formed by appropriate printing processes on the printed surface 2 of the substrate film 1, including the printed surface 2A of the first region A and the printed surface 2B of the second region B, are simplified and shown as a common layer.

According to the capacitive touch switch X manufactured through the above processing steps, the first region A, which has a touch portion T at a predetermined location on the printed surface 2A, functions as a sensor layer, and the second region B, which has a ground portion G covering most of the printed surface 2B, functions as a ground layer. This allows for detection of when a user's finger or hand approaches the touch electrode T, and enables its use as a digital input device for detecting the on/off state of the switch. Therefore, by attaching, for example, double-sided tape to an appropriate location on the capacitive touch switch X and mounting it to the component on which the touch switch X is to be mounted, it can be used as a practical product in various applications. For example, it can be used in display panels and key buttons of home appliances, audio equipment, and car navigation systems. When using the capacitive touch switch X, the terminal portion 6 set at the tip of the first flexible 6A should be inserted into a connector component mounted on an appropriate circuit board, which is a separate part from the aforementioned circuit board film 1.

Furthermore, the capacitive touch switch X according to this embodiment has a two-layer substrate structure formed by folding a single base film 1. The touch electrode T, circuit P (power supply line), ground portion G, and resist are printed only on the same surface (printed surface 2) of the base film 1 in its unfolded state before folding. The outward-bent state is maintained by bonding the inward-facing non-printed surfaces 3 together with an adhesive material 7 (adhesive layer) when the substrate is folded along a predetermined first folding line 4 so that the printed surface 2A of the first region A and the printed surface 2B of the second region B face outwards from each other (outward-bent state). As a result, the processing of creating through holes is unnecessary, and the number of printing processes on the base film 1 can be reduced. Furthermore, according to this embodiment of the capacitive touch switch X, compared to a configuration where the printed surface 2A of the first region A and the printed surface 2B of the second region B are bent inward (inward-bent state), the distance between the printed surface 2A of the first region A and the printed surface 2B of the second region B can be increased by twice the thickness of the base film 1 plus the thickness of the adhesive layer 7. As a result, when a self-capacitive capacitive touch switch X is configured, the distance from the touch electrode T (sensor layer) on the printed surface 2A of the first region A to the ground portion G (ground layer) on the printed surface 2B of the second region B can be increased compared to the inward-bent state. This prevents and suppresses the problem where the closer the ground portion G is to the touch electrode T, the higher the parasitic capacitance tends to be, leading to a decrease in signal strength.

Furthermore, with this type of two-layer capacitive touch switch X, the second region B (ground layer), which performs the grounding function, can also provide a shielding effect.

Furthermore, if an inward-bending configuration is adopted and the distance between the printed surface 2A of the first region A and the printed surface 2B of the second region B is to be increased, the thickness of the adhesive material 7 (adhesive layer) will need to be increased, resulting in an increase in the overall thickness of the touch switch X. In this respect, the capacitive touch switch X according to this embodiment has an advantageous structure.

As an example of a capacitive touch switch similar to the first embodiment, although not shown, a capacitive touch switch can be described in which a shield portion is formed by printing on the printed surface of the second region instead of a ground portion, and the switch is folded along the first fold line so that the printed surfaces of the first region and the second region face outwards from each other (outward-bent state). Such a capacitive touch switch is also included in the present invention, and like the capacitive touch switch according to the first embodiment, it eliminates the need for processing to create through holes and reduces the number of printing processes on the base film. Furthermore, compared to a configuration where the printed surfaces of the first and second regions face inwards from each other (inward-bent state), the distance from the touch electrode (sensor layer) on the printed surface of the first region to the shield portion (shield layer) on the printed surface of the second region can be increased by twice the thickness of the base film plus the thickness of the adhesive layer, thereby increasing the shielding effect.

<Second Embodiment>
The capacitive touch switch X according to this embodiment is characterized by a three-layer structure formed by folding and laminating a single base film 1 (PET base film), as shown in Figures 5 to 8. Figure 5 is a front view of the capacitive touch switch X according to this embodiment, Figure 6 is a view in direction a (side view) of Figure 5, Figure 7 is a view in direction b (side view) of Figure 5, and Figure 8 is a front view of the capacitive touch switch X (capacitive touch switch X with the base film 1 unfolded) at the time the printing process described later is completed. Note that in Figures 6 and 7, the thickness is exaggerated to be thicker than the actual thickness for illustrative purposes.

In this embodiment, a flexible printed circuit board (FPC) with a predetermined thickness (for example, about 100 μm) and high transparency is used as the base film 1, which is the base film for circuit printing. One side of the single base film 1 in its unfolded state before folding is set as the printing side 2 (conductive side), and the other side is set as the non-printing side 3 (non-conductive side). In the unfolded single base film 1, the first region A, the second region B, and the third region C are arranged in this order, a first fold line 4 is set at the boundary between the first region A and the second region B, and a second fold line 8 is set at the boundary between the second region B and the third region C. The touch electrode T, circuit P (power supply line), and ground section G are printed on the printing surface 2A of the first region A, the shield section S and circuit P (power supply line) are printed on the printing surface 2B of the second region B (the central region in Figure 8), and the ground section G and circuit P (power supply line) are printed on the printing surface 2C of the third region C (printing process S1, see Figure 4). In this embodiment, screen printing is used as the printing method in printing process S1.

In this embodiment, the touch electrodes T and shield portion S are formed using, for example, PEDOT (polyethylenedioxythiophene) or ITO (indium tin oxide) by the printing process S1, and the circuit P (power supply line) and ground portion G can be formed using, for example, silver paste. As shown in Figure 8, multiple touch electrodes T (four in the illustrated example) are provided at a predetermined pitch in the longitudinal direction of the first region A, the shield portion S is provided in a solid coating manner over substantially the entire area of the second region B except for the peripheral edge, and the ground portion G is provided in a frame shape surrounding the touch electrodes T arranged at a predetermined pitch in the first region A, and is provided in a mesh manner over substantially the entire area of the third region C except for the area surrounded by a circle (four circles in the illustrated example) that is slightly larger than each touch electrode T and the peripheral edge.

Therefore, in the state after bonding process S2, the touch electrode T and the ground portion G do not overlap in a plan view, while the circuit P (power supply line) and the ground portion G partially overlap. While placing the ground portion G around the touch electrode T can prevent malfunctions due to electromagnetic field noise, there is a possibility of reduced touch sensitivity due to parasitic capacitance from the ground portion G. Therefore, it is preferable to make the ground portion G a mesh shape to reduce parasitic capacitance (see Figure 8). Providing the ground portion G can reduce noise and stabilize the signal level. In this embodiment, the ground portion G is also provided in a mesh shape in almost the entire area of the first region A, excluding each touch electrode T, the circuit P (power supply line), and the peripheral area.

In this embodiment, since the circuit P (power supply line) and the ground section G are made of the same material, these circuits P (power supply line) and ground section G can be printed at the same timing on the printing surface 2A of the first region A and the printing surface 2C of the third region C of a single base film 1. Furthermore, since the touch electrode T and the shield section S are made of the same material, the touch electrode A and the shield section S can be printed at the same timing on the printing surface 2A of the first region A and the printing surface 2B of the second region B of a single base film 1. Moreover, in this embodiment, the circuits P (power supply line) connecting the circuits P (power supply line) and ground sections G of each region (first region A, second region B, third region C) are printed in printing step S1 at positions spanning the first region A and the second region B, and at positions spanning the second region B and the third region C, respectively (see Figure 8).

Furthermore, in this embodiment, the printing process S1 is configured to print a resist (insulating layer) using resist ink at appropriate locations on the printing surface 2 (locations where the touch electrode T, circuit P, and ground G are not printed). The resist serves both to protect and insulate the silver from PEDOT or ITO, and is formed using, for example, a highly transparent material that does not adversely affect the light transmittance of the touch electrode T.

In this embodiment, slits 5 (small holes shown in Figure 8) are formed at predetermined locations along the first fold line 4 and the second fold line 8 of the base film 1, facilitating the folding process along the first fold line 4 and the second fold line 8. In this embodiment, two slits 5 are formed along each fold line (first fold line 4, second fold line 8) (see Figure 8).

The base film 1 integrally has a first flexible portion 6A with a terminal portion 6, which functions as a terminal, set at the tip of an edge corresponding to one of the longer sides of the peripheral edge of the first region A. Circuits P (power supply lines) and ground portions G are also provided at predetermined locations on the same surface as the printed surface 2A (the printed surface of the first flexible portion 6A) of the first flexible portion 6A, including the terminal portion 6, by the printing process in the printing step S1. In particular, carbon is provided on the terminal portion 6 by the printing process in the printing step S1 to ensure the conductivity of the terminal portion 6. By providing a reinforcing plate 61 on the terminal portion 6, it is also possible to adjust the thickness so that it can be inserted into a connector. Furthermore, in this embodiment, the second flexible portion 6B and the third flexible portion 6C, corresponding to the first flexible portion 6A, are integrally formed at the edges of the second region B and the third region C. Circuits P (power supply lines), shield portions S, or ground portions G are provided at predetermined locations on the same surfaces as the printed surfaces 2B and 2C (the printed surface of the second flexible portion 6B and the printed surface of the third flexible portion 6C) of the second flexible portion 6B and the third flexible portion 6C by the printing process in printing step S1. Note that the longitudinal dimensions of the second flexible portion 6B and the third flexible portion 6C are shorter than those of the first flexible portion 6A by the amount of the terminal portion 6. In other words, the terminal portion 6 is not provided in the second flexible portion 6B and the third flexible portion 6C.

After performing a printing process on the base film 1 (after the printing process S1), the capacitive touch switch X according to this embodiment can be manufactured by performing a process of folding and bonding the base film 1 along the first folding line 4 and the second folding line 8 (bonding process S2, see Figure 4). In the bonding process S2, as shown in Figures 6 and 7, a first bonding process is performed in which the printed surface 2A of the first region A and the printed surface 2B of the second region B are folded outwards (outward bending), and the non-printed surface 3A of the first region A and the non-printed surface 3B of the second region B are bonded together via adhesive 7 so that they face each other. Following the first bonding process, a second bonding process is performed in which the printed surface 3B of the second region B and the printed surface 3C of the third region C are folded outwards (outward bending), and the non-printed surface 3C of the third region C and the printed surface 2A of the first region A are bonded together via adhesive 7 so that they face each other. Furthermore, in the first bonding process, the first flexible part 6A and the second flexible part 6B are bonded together via adhesive 7 with their printed surfaces facing outwards. In the second bonding process, the non-printed surface of the third flexible part 6C and the printed surface of the first flexible part 6A are bonded together via adhesive 7 with their printed surfaces facing outwards.

The application of the adhesive 7 can be performed simultaneously with or with a time delay from the printing process. In this embodiment, silicone OCA (Optical Clear Adhesive) is used as the adhesive 7. Other adhesives, such as double-sided tape, can also be used as the adhesive 7. The thickness of the capacitive touch switch X can also be adjusted by adjusting the thickness of the adhesive layer on which the adhesive 7 is placed. Figures 6 and 7 show simplified schematic representations of the touch electrode T, ground portion G, and shield portion S on each printed surface in the c-c and d-d cross-sections of Figure 5, respectively.

The capacitive touch switch X according to this embodiment, manufactured through the above processing steps, has a three-layer substrate structure arranged in the order of a third region C, a first region A, and a second region B. The third region C, which has a ground portion G over most of the printed surface 2C, functions as a ground layer; the first region A, which has a touch portion T at a predetermined location on the printed surface 2A, functions as a sensor layer; and the second region B, which has a shield portion S over most of the printed surface 2B, functions as a shield layer. This allows for detection of when a user's finger or hand approaches the touch electrode T from the third region C side, which is the sensing direction Y, and it can be used as a digital input device to detect the on/off state of the switch. Therefore, by attaching, for example, double-sided tape to an appropriate location on the capacitive touch switch X and mounting it to the component on which the touch switch X is to be mounted, it can be used as a practical product for various applications. For example, it can be used in display panels and key buttons for home appliances, audio equipment, and car navigation systems. When using the capacitive touch switch X, simply insert the terminal portion 6 at the tip of the first flexible switch 6A into a connector component mounted on a suitable circuit board, which is a separate part from the aforementioned circuit board film 1.

Furthermore, the capacitive touch switch X according to this embodiment has a three-layer substrate structure formed by folding a single substrate film 1. The touch electrode T, circuit P (power supply line), ground portion G, and resist are printed only on the same surface (printed surface 2) of the substrate film 1 in its unfolded state before folding. In a state where the substrate film is folded along the first folding line 4 such that the printed surface 2A of the first region A and the printed surface 2B of the second region B face outwards from each other (outward-bent state), the non-printed surfaces 3 facing inwards are connected by an adhesive material 7 (adhesive layer). By bonding them together, the outward bent state is maintained. Furthermore, in a state where the printed surface 2B of the second region B and the printed surface 2C of the third region C face outwards from each other along the second bending line 8 (outward bent state), the non-printed surface 3C of the third region C and the printed surface 2A of the first region A, which face each other, are bonded together with the adhesive material 7 (adhesive layer) to maintain the outward bent state. As a result, the processing of providing through holes is unnecessary, and the number of printing processes on the base film 1 can be reduced. Moreover, according to the capacitive touch switch X of this embodiment, compared to a configuration where the printed surface 2A of the first region A and the printed surface 2B of the second region B face inwards from each other (inward bent state), the distance between the touch electrode T (sensor layer) provided on the printed surface 2A of the first region A and the shield portion S (shield layer) provided on the printed surface 2B of the second region B can be made larger by twice the thickness dimension of the base film 1 plus the thickness of the adhesive layer 7. As a result, when a self-capacitive type capacitive touch switch X is configured, the shielding effect is increased compared to a configuration where only a distance equivalent to the thickness of the base film 1 (one times the thickness) can be secured between the shield layer and the sensor layer.

Furthermore, the capacitive touch switch X according to this embodiment can ensure a distance from the touch electrode T (sensor layer) provided on the printed surface 2A of the first region A to the ground portion G (ground layer) provided on the printed surface 2C of the third region C that is equal to the sum of the thickness of the base film 1 and the thickness of the adhesive layer 7. Compared to configurations where only a distance equivalent to the thickness of the base film 1 (1 times the thickness) can be secured between the sensor layer and the ground layer, or where only a distance equivalent to the thickness of the adhesive layer 7 can be secured between the sensor layer and the ground layer, this configuration makes it easier to suppress the problem where parasitic capacitance increases and signal strength decreases as the ground portion G approaches the touch electrode T.

<Third Embodiment>
As shown in Figures 9 to 12, the capacitive touch switch X according to this embodiment is characterized by a three-layer structure formed by folding and laminating a single base film 1 (PET base film). Compared with the capacitive touch switch X according to the second embodiment described above, the capacitive touch switch X according to the second embodiment has a configuration in which, in the unfolded state, the second region B, which functions as a shield layer, is adjacent to the first region A (sensor layer) with the first fold line 4 in between, and the third region C, which functions as a ground layer, is adjacent to the second region B with the first fold line 8 in between. In contrast, in the unfolded state, the second region B, which functions as a ground layer, is adjacent to the first region A (sensor layer) with the first fold line 4 in between, and the third region C, which functions as a shield layer, is adjacent to the second region B with the second fold line 8 in between. Figure 9 is a front view of the capacitive touch switch X according to this embodiment, Figure 10 is a view in direction a (side view) of Figure 9, Figure 11 is a view in direction b (side view) of Figure 9, and Figure 12 is a front view of the capacitive touch switch X (capacitive touch switch X with the base film 1 unfolded) at the time the printing process described later is completed. Note that in Figures 10 and 11, the thickness is exaggerated to be thicker than the actual thickness for explanatory purposes.

In this embodiment, a flexible printed circuit board (FPC) with a predetermined thickness (for example, about 100 μm) and high transparency is used as the base film 1, which is the base film for circuit printing. One side of the single base film 1 in its unfolded state before folding is set as the printing side 2 (conductive side), and the other side is set as the non-printing side 3 (non-conductive side). In the unfolded single base film 1, the first region A, the second region B, and the third region C are arranged in this order, a first fold line 4 is set at the boundary between the first region A and the second region B, and a second fold line 8 is set at the boundary between the second region B and the third region C. The touch electrode T, circuit P (power supply line), and ground section G are printed on the printing surface 2A of the first region A, the ground section G and circuit P (power supply line) are printed on the printing surface 2B of the second region B (the central region in Figure 12), and the shield section S and circuit P (power supply line) are printed on the printing surface 2C of the third region C (printing process S1, see Figure 4). In this embodiment, screen printing is used as the printing method in printing process S1.

In this embodiment, the touch electrodes T and shield portion S are formed using, for example, PEDOT (polyethylenedioxythiophene) or ITO (indium tin oxide) by the printing process S1, and the circuit P (power supply line) and ground portion G can be formed using, for example, silver paste. As shown in Figure 12, multiple touch electrodes T (four in the illustrated example) are provided at a predetermined pitch in the longitudinal direction of the first region A, the shield portion S is provided in a solid coating manner over substantially the entire area of the third region C except for the peripheral edge, and the ground portion G is provided in a frame shape surrounding the touch electrodes T arranged at a predetermined pitch in the first region A, and in a mesh shape over substantially the entire area of the second region B except for the area surrounded by a circle (four circles in the illustrated example) that is slightly larger than each touch electrode T and the peripheral edge.

Therefore, in the state after bonding process S2, the touch electrodes T and the ground portion G do not overlap in a plan view, while the circuit P (power supply line) and the ground portion G partially overlap. While placing the ground portion G around the touch electrodes T can prevent malfunctions due to electromagnetic field noise, there is a possibility of reduced touch sensitivity due to parasitic capacitance from the ground portion G. Therefore, it is preferable to make the ground portion G a mesh shape to reduce parasitic capacitance (see Figures 9 and 12). Providing the ground portion G can reduce noise and stabilize the signal level. In this embodiment, the ground portion G is also provided in a mesh shape in almost the entire area of the first region A, excluding each touch electrode T, the circuit P (power supply line), and the peripheral area.

In this embodiment, since the circuit P (power supply line) and the ground section G are made of the same material, these circuits P (power supply line) and ground section G can be printed at the same timing on the printing surface 2A of the first region A and the printing surface 2B of the second region B of a single base film 1. Furthermore, since the touch electrode T and the shield section S are made of the same material, the touch electrode A and the shield section S can be printed at the same timing on the printing surface 2A of the first region A and the printing surface 2C of the third region C of a single base film 1. Moreover, in this embodiment, the circuits P (power supply line) connecting the circuits P (power supply line) and ground sections G of each region (first region A, second region B, third region C) are printed in printing step S1 at positions spanning the first region A and the second region B, and at positions spanning the second region B and the third region C, respectively (see Figure 12).

Furthermore, in this embodiment, the printing process S1 is configured to print a resist (insulating layer) using resist ink at appropriate locations on the printing surface 2 (locations where the touch electrode T, circuit P, and ground G are not printed). The resist serves both to protect and insulate the silver from PEDOT or ITO, and is formed using, for example, a highly transparent material that does not adversely affect the light transmittance of the touch electrode T.

In this embodiment, slits 5 (small holes shown in Figure 13) are formed at predetermined locations along the first fold line 4 and the second fold line 8 of the base film 1, facilitating the folding process along the first fold line 4 and the second fold line 8. In this embodiment, two slits 5 are formed along each fold line (first fold line 4, second fold line 8) (see Figure 13).

The base film 1 integrally has a first flexible portion 6A with a terminal portion 6, which functions as a terminal, set at the tip of an edge corresponding to one of the longer sides of the peripheral edge of the first region A. Circuits P (power supply lines) and ground portions G are also provided at predetermined locations on the same surface as the printed surface 2A (the printed surface of the first flexible portion 6A) of the first flexible portion 6A, including the terminal portion 6, by the printing process in the printing step S1. In particular, carbon is provided on the terminal portion 6 by the printing process in the printing step S1 to ensure the conductivity of the terminal portion 6. By providing a reinforcing plate 61 on the terminal portion 6, it is also possible to adjust the thickness so that it can be inserted into a connector. Furthermore, in this embodiment, the second flexible portion 6B and the third flexible portion 6C, corresponding to the first flexible portion 6A, are integrally formed at the edges of the second region B and the third region C. Circuit P (power supply line), ground portion G, or shield portion S are provided at predetermined locations on the same surfaces as the printed surfaces 2B and 2C (the printed surface of the second flexible portion 6B and the printed surface of the third flexible portion 6C) of the second flexible portion 6B and the third flexible portion 6C by the printing process in printing step S1. Note that the longitudinal length of the second flexible portion 6B and the third flexible portion 6C is shorter than that of the first flexible portion 6A by the amount of the terminal portion 6. In other words, the terminal portion 6 is not provided in the second flexible portion 6B and the third flexible portion 6C.

After performing a printing process on the base film 1 (after the printing process S1), the capacitive touch switch X according to this embodiment can be manufactured by performing a process of folding and bonding the base film 1 along the first folding line 4 and the second folding line 8 (bonding process S2, see Figure 4). In the bonding process S2, as shown in Figures 10 and 11, a first bonding process is performed in which the printed surface 2A of the first region A and the printed surface 2B of the second region B are folded outwards (outward bending), and the non-printed surface 3A of the first region A and the non-printed surface 3B of the second region B are bonded together via adhesive 7 so that they face each other. Following the first bonding process, a second bonding process is performed in which the printed surface 3B of the second region B and the printed surface 3C of the third region C are folded outwards (outward bending), and the non-printed surface 3C of the third region C and the printed surface 2A of the first region A are bonded together via adhesive 7 so that they face each other. Furthermore, in the first bonding process, the first flexible part 6A and the second flexible part 6B are bonded together via adhesive 7 with their printed surfaces facing outwards. In the second bonding process, the non-printed surface of the third flexible part 6C and the printed surface of the first flexible part 6A are bonded together via adhesive 7 with their printed surfaces facing outwards.

The application of the adhesive 7 can be performed simultaneously with or with a time delay from the printing process. In this embodiment, silicone OCA (Optical Clear Adhesive) is used as the adhesive 7. Other adhesives, such as double-sided tape, can also be used as the adhesive 7. The thickness of the capacitive touch switch X can also be adjusted by adjusting the thickness of the adhesive layer on which the adhesive 7 is placed. Figures 10 and 11 show simplified schematic representations of the touch electrode T, ground portion G, and shield portion S on each printed surface in the c-c and d-d cross-sections of Figure 9, respectively.

The capacitive touch switch X according to this embodiment, manufactured through the above processing steps, has a three-layer substrate structure arranged in the order of third region C, first region A, and second region B. The third region C, which has a ground portion G over most of the printed surface 2C, functions as a ground layer; the first region A, which has a touch portion T at a predetermined location on the printed surface 2A, functions as a sensor layer; and the second region B, which has a ground portion G over most of the printed surface 2B, functions as a shield layer. This allows for detection of when a user's finger or hand approaches the touch electrode T from the third region C (ground layer) side, which is the sensing direction Y, and it can be used as a digital input device to detect the on/off state of the switch. Therefore, by attaching, for example, double-sided tape to an appropriate location on the capacitive touch switch X and mounting it to the component on which the touch switch X is to be mounted, it can be used as a practical product for various applications. For example, it can be used in display panels and key buttons of home appliances, audio equipment, and car navigation systems. When using the capacitive touch switch X, simply insert the terminal portion 6 at the tip of the first flexible switch 6A into a connector component mounted on a suitable circuit board, which is a separate part from the aforementioned circuit board film 1.

Furthermore, the capacitive touch switch X according to this embodiment has a three-layer substrate structure formed by folding a single substrate film 1. The touch electrode T, circuit P (power supply line), ground portion G, and resist are printed only on the same surface (printed surface 2) of the substrate film 1 in its unfolded state before folding. In a state where the substrate film is folded along a predetermined first folding line 4 such that the printed surface 2A of the first region A and the printed surface 2B of the second region B face outwards from each other (outward bending state), the non-printed surfaces 3 facing inwards from each other are bonded together with an adhesive 7 (adhesive). The outward-bent state is maintained by bonding the layers together, and the outward-bent state is maintained by bonding the non-printed surface 2C of the third region C and the printed surface 2A of the first region A with the adhesive material 7 (adhesive layer) when the printed surface 2B of the second region B and the printed surface 2C of the third region C are folded outwards along the second bending line 8 (outward-bent state), so that the processing to create through holes is unnecessary and the number of printing processes on the base film 1 can be reduced. Furthermore, with the capacitive touch switch X according to this embodiment, compared to a configuration in which the printed surface 2A of the first region A and the printed surface 2B of the second region B are folded inwards (inward-bent state), the distance between the printed surface 2A of the first region A and the printed surface 2B of the second region B can be made larger by twice the thickness dimension of the base film 1 plus the thickness of the adhesive layer 7. As a result, when a self-capacitive capacitive touch switch X is configured, the distance from the touch electrode T (sensor layer) provided on the printed surface 2A of the first region A to the ground portion G (ground layer) provided on the printed surface 2B of the second region B can be made larger compared to the inward-bending state. This prevents and suppresses the problem where the closer the ground portion G is to the touch electrode T, the higher the parasitic capacitance tends to be, resulting in a decrease in signal strength.

Furthermore, the capacitive touch switch X according to this embodiment can ensure a distance from the touch electrode T (sensor layer) provided on the printed surface 2A of the first region A to the shield portion S (shield layer) provided on the printed surface 2C of the third region C that is equal to the sum of the thickness of the base film 1 and the thickness of the adhesive layer 7. This increases the shielding effect compared to configurations where only a distance equivalent to the thickness of the base film 1 (one times the thickness) can be secured between the sensor layer and the shield layer, or where only a distance equivalent to the thickness of the adhesive layer 7 can be secured between the sensor layer and the shield layer.

<Fourth Embodiment>
The capacitive touch switch X according to this embodiment, as shown in Figures 13 to 16, is characterized by a three-layer structure formed by folding and laminating a single base film 1 (PET base film). Compared with the capacitive touch switch X according to the second and third embodiments described above, it differs in that, in the unfolded state, a first region A (sensor layer) is located in the center, a second region B is adjacent to one side of the first region A (sensor layer) via a first fold line 4, and a third region is adjacent to the other side via a second fold line 8. Figure 13 is a front view of the capacitive touch switch X according to this embodiment, Figure 14 is a view in direction a (side view) of Figure 13, Figure 15 is a view in direction b (side view) of Figure 13, and Figure 16 is a front view of the capacitive touch switch X (capacitive touch switch X with the base film 1 in the unfolded state) at the time the printing process is completed. Note that in Figures 14 and 15, the thickness is exaggerated to be thicker than the actual thickness for illustrative purposes.

In this embodiment, a flexible printed circuit board (FPC) with a predetermined thickness (for example, about 100 μm) and high transparency is used as the base film 1, which is the base film for circuit printing. One side of the single base film 1 in its unfolded state before folding is set as the printing side 2 (conductive side), and the other side is set as the non-printing side 3 (non-conductive side). In the unfolded single base film 1, the second region B, the first region A, and the third region C are arranged in this order, a first fold line 4 is set at the boundary between the second region B and the first region A, and a second fold line 8 is set at the boundary between the first region A and the third region C. The touch electrode T, circuit P (power supply line), and ground section G are printed on the printing surface 2A of the first region A, the shield section S and circuit P (power supply line) are printed on the printing surface 2C of the third region C, and the ground section G and circuit P (power supply line) are printed on the printing surface 2B of the second region B (the central region in Figure 5) (printing process S1, see Figure 4). In this embodiment, screen printing is used as the printing method in printing process S1.

In this embodiment, the touch electrodes T and shield portion S are formed using, for example, PEDOT (polyethylenedioxythiophene) or ITO (indium tin oxide) by the printing process S1, and the circuit P (power supply line) and ground portion G can be formed using, for example, silver paste. As shown in Figure 16, multiple touch electrodes T (four in the illustrated example) are provided at a predetermined pitch in the longitudinal direction of the first region A, the shield portion S is provided in a solid coating manner over substantially the entire area of the second region B except for the peripheral edge, and the ground portion G is provided in a frame shape surrounding the touch electrodes T arranged at a predetermined pitch in the first region A, and is provided in a mesh manner over substantially the entire area of the third region C except for the area surrounded by a circle (four circles in the illustrated example) that is slightly larger than each touch electrode T and the peripheral edge.

Therefore, in the state after bonding process S2, the touch electrodes T and the ground portion G do not overlap in a plan view, while the circuit P (power supply line) and the ground portion G partially overlap. While placing the ground portion G around the touch electrodes T can prevent malfunctions due to electromagnetic field noise, there is a possibility of reduced touch sensitivity due to parasitic capacitance from the ground portion G. To reduce parasitic capacitance, it is preferable to make the ground portion G a mesh shape (see Figures 13 and 16). Providing the ground portion G can reduce noise and stabilize the signal level. In this embodiment, the ground portion G is also provided in a mesh shape in almost the entire area of the first region A, excluding each touch electrode T, the circuit P (power supply line), and the peripheral area.

In this embodiment, since the circuit P (power supply line) and the ground section G are made of the same material, these circuits P (power supply line) and ground section G can be printed at the same timing on the printing surface 2A of the first region A and the printing surface 2C of the third region C of a single base film 1. Furthermore, since the touch electrode T and the shield section S are made of the same material, the touch electrode A and the shield section S can be printed at the same timing on the printing surface 2A of the first region A and the printing surface 2B of the second region B of a single base film 1. Moreover, in this embodiment, the circuits P (power supply line) connecting the circuits P (power supply line) and ground sections G of each region (first region A, second region B, third region C) are printed in printing step S1 at positions spanning the first region A and the second region B, and at positions spanning the second region B and the third region C, respectively (see Figure 16).

Furthermore, in this embodiment, the printing process S1 is configured to print a resist (insulating layer) using resist ink at appropriate locations on the printing surface 2 (locations where the touch electrode T, circuit P, and ground G are not printed). The resist serves both to protect and insulate the silver from PEDOT or ITO, and is formed using, for example, a highly transparent material that does not adversely affect the light transmittance of the touch electrode T.

In this embodiment, slits 5 (small holes shown in Figure 16) are formed at predetermined locations along the first fold line 4 and the second fold line 8 of the base film 1, facilitating the folding process along the first fold line 4 and the second fold line 8. In this embodiment, three slits 5 are formed along each fold line (first fold line 4, second fold line 8) (see Figure 16).

The base film 1 integrally has a first flexible portion 6A with a terminal portion 6, which functions as a terminal, set at the tip of an edge corresponding to one of the longer sides of the peripheral edge of the first region A. Circuits P (power supply lines) and ground portions G are also provided at predetermined locations on the same surface as the printed surface 2A (the printed surface of the first flexible portion 6A) of the first flexible portion 6A, including the terminal portion 6, by the printing process in the printing step S1. In particular, carbon is provided on the terminal portion 6 by the printing process in the printing step S1 to ensure the conductivity of the terminal portion 6. By providing a reinforcing plate 61 on the terminal portion 6, it is also possible to adjust the thickness so that it can be inserted into a connector. Furthermore, in this embodiment, the second flexible portion 6B and the third flexible portion 6C, corresponding to the first flexible portion 6A, are integrally formed at the edges of the second region B and the third region C. Circuits P (power supply lines), shield portions S, or ground portions G are provided at predetermined locations on the same surfaces as the printed surfaces 2B and 2C (the printed surface of the second flexible portion 6B and the printed surface of the third flexible portion 6C) of the second flexible portion 6B and the third flexible portion 6C by the printing process in printing step S1. Note that the longitudinal length of the second flexible portion 6B and the third flexible portion 6C is shorter than that of the first flexible portion 6A by the amount of the terminal portion 6. In other words, the terminal portion 6 is not provided in the second flexible portion 6B and the third flexible portion 6C.

After performing a printing process on the base film 1 (after the printing process S1), the capacitive touch switch X according to this embodiment can be manufactured by performing a process of folding and bonding the base film 1 along the first folding line 4 and the second folding line 8 (bonding process S2, see Figure 4). In the bonding process S2, as shown in Figures 14 and 15, a first bonding process is performed in which the printed surface 2A of the first region A and the printed surface 2B of the second region B are folded outwards (outward bending), and the non-printed surface 3A of the first region A and the non-printed surface 3B of the second region B are bonded together via adhesive 7. Following the first bonding process, a second bonding process is performed in which the printed surface 2A of the first region A and the printed surface 2C of the third region C are folded inwards (inward bending), and the non-printed surface 3C of the third region C and the printed surface 2B of the second region B are bonded together via adhesive 7. Furthermore, in the first bonding process, the first flexible part 6A and the second flexible part 6B are bonded together via adhesive 7 with their printed surfaces facing outwards. In the second bonding process, the first flexible part 6A and the third flexible part 6C are bonded together via adhesive 7 with their printed surfaces facing inwards.

The application of the adhesive 7 can be performed simultaneously with or with a time delay from the printing process. In this embodiment, silicone OCA (Optical Clear Adhesive) is used as the adhesive 7. Other adhesives, such as double-sided tape, can also be used as the adhesive 7. The thickness of the capacitive touch switch X can also be adjusted by adjusting the thickness of the adhesive layer on which the adhesive 7 is placed. Figures 14 and 15 show simplified schematic representations of the touch electrode T, ground portion G, and shield portion S on each printed surface in the c-c and d-d cross-sections of Figure 13, respectively.

The capacitive touch switch X manufactured according to this embodiment through the above processing steps has a three-layer substrate structure with the third region C, first region A, and second region B arranged in that order. The third region C functions as the ground layer, the first region A functions as the sensor layer, and the second region B functions as the shield layer. This allows detection of a user's finger or hand approaching the touch electrode T from the third region C (ground layer) side, which is the sensing direction Y, and enables its use as a digital input device for detecting the on/off state of the switch. Therefore, by attaching, for example, double-sided tape to an appropriate location on the capacitive touch switch X and mounting it to the component on which the touch switch X is to be mounted, it can be used as a practical product in various applications. For example, it can be used in display panels and key buttons of home appliances, audio equipment, and car navigation systems. When using the capacitive touch switch X, the terminal portion 6 set at the tip of the first flexible 6A should be inserted into a connector component mounted on an appropriate substrate side, which is a separate part from the substrate film 1 described above.

Furthermore, the capacitive touch switch X according to this embodiment has a three-layer substrate structure formed by folding a single substrate film 1. The touch electrode T, circuit P (power supply line), ground portion G, and resist are printed only on the same surface (printed surface 2) of the substrate film 1 in its unfolded state before folding. In a state where the substrate film is folded along a predetermined first folding line 4 such that the printed surface 2A of the first region A and the printed surface 2B of the second region B face outwards from each other (outward bending state), the non-printed surfaces 3 facing inwards from each other are bonded together with an adhesive 7 (adhesive). The outward bent state is maintained by bonding with an adhesive layer, and the inward bent state is maintained by bonding the mutually facing printed surfaces 2A of the first region A and 2C of the third region C with an adhesive material 7 (adhesive layer) when the printed surfaces 2A of the first region A and 2C of the third region C are bent inward along the second bending line 8 (inward bent state). Therefore, the processing of providing through holes is unnecessary, and the number of printing processes on the base film 1 can be reduced. Furthermore, with the capacitive touch switch X according to this embodiment, compared to a configuration in which the printed surfaces 2A of the first region A and 2B of the second region B are bent inward (inward bent state), the distance between the touch electrode T (sensor layer) provided on the printed surface 2A of the first region A and the shield portion S (shield layer) provided on the printed surface 2B of the second region B can be made larger by twice the thickness dimension of the base film 1 plus the thickness of the adhesive layer 7. Specifically, the capacitive touch switch X according to this embodiment can secure a distance equivalent to twice the thickness of the base film 1 between the shield portion S (shielding layer) provided on the printed surface 2B of the second region B and the touch electrode T (sensor layer) provided on the printed surface 2A of the first region A. As a result, compared to a self-capacitive capacitive touch switch X where the shield layer and sensor layer are bent inward, or where only a distance equivalent to the thickness of the base film 1 (one times the thickness) can be secured between the shield layer and sensor layer, the distance from the touch electrode T (sensor layer) on the printed surface 2A of the first region A to the shield portion S (shielding layer) on the printed surface 2B of the second region B can be increased, thereby increasing the shielding effect.

Furthermore, as a capacitive touch switch similar to the fourth embodiment, although not shown, a capacitive touch switch with a three-layer substrate structure in which the second region functions as a ground layer, the first region functions as a sensor layer, and the third region functions as a shield layer are arranged in this order in the sensing direction via an adhesive layer is also included in the present invention. This is achieved by applying a capacitive touch switch with a capacitive touch switch similar to the fourth embodiment, in which a ground portion is formed on the printed surface of the second region by printing and a shield portion is formed on the printed surface of the third region by printing, and the substrate is folded along the first fold line so that the printed surfaces of the first region and the second region face outwards from each other (outward bend state), and the parts of the first and second regions that face each other (non-printed surfaces) are bonded together. In this case as well, the processing required to create through-holes is unnecessary, the number of printing processes on the base film can be reduced, and the distance between the touch electrode (sensor layer) on the printed surface of the first region and the ground portion (ground layer) on the printed surface of the second region can be increased by twice the thickness of the base film plus the thickness of the adhesive layer. This prevents and suppresses the problem where the closer the ground layer is to the sensor layer, the higher the parasitic capacitance tends to be, resulting in a decrease in signal strength.

Furthermore, the present invention is not limited to the embodiments described above. For example, the material and size of the base film may be changed, or the materials of the ground and shield portions may be changed. In addition to silver, ECP (Electric Conductive paste) or carbon can be used as the material for the ground portion. Also, the ground portion is not limited to a mesh structure; it may be a solid coating.

The printing locations and patterns of the touch electrodes and ground areas on the printed surface of the base film can also be changed as needed.

Furthermore, the specific configuration of each part is not limited to the above embodiments, and various modifications are possible without departing from the spirit of the present invention.

1... Base film 2, 2A, 2B, 2C... Printing surface 3, 3A, 3B, 3C... Non-printing surface 4... First bending line 6... Terminal portion 7... Adhesive layer (adhesive material)
8...Second folding line A...First region B...Second region C...Third region G...Ground section S...Shield section T...Touch electrode X...Capacitive touch switch

Claims (6)

A capacitive touch switch having at least touch electrodes provided on a thin substrate film by a printing process,
The invention comprises a single substrate film in which one side is set as the printing surface and the other side is set as the non-printing surface,
In the base film, at least the touch electrodes are provided by printing on the printed surface of a first region bounded by a predetermined first fold line, and at least a ground portion or shield portion is provided by printing on the printed surface of a second region adjacent to the first region across the first fold line, and the shield portion or ground portion is provided by printing on the printed surface of a third region adjacent to the second region across the second fold line.
The first and second regions are folded outwards along the first fold line such that the printed surfaces of the first and second regions do not face each other, and the non-printed surfaces of the first and second regions that face each other are bonded together.
A capacitive touch switch characterized in that, in an outward-folded state where the printed surfaces of the second region and the third region do not face each other along the second fold line, the second region, the first region, and the third region are arranged in this order in the stacking direction, and the portions of the first region and the third region that face each other are bonded together. A capacitive touch switch having at least touch electrodes provided on a thin substrate film by a printing process,
The invention comprises a single substrate film in which one side is set as the printing surface and the other side is set as the non-printing surface,
In the substrate film, at least the touch electrodes are provided by printing on the printed surface of a first region bounded by a predetermined first fold line, and at least a ground portion or shield portion is provided by printing on the printed surface of a second region adjacent to the first region across the first fold line, and the shield portion or ground portion is provided by printing on the printed surface of a third region adjacent to the first region across the second fold line,
The first and second regions are folded outwards along the first fold line such that the printed surfaces of the first and second regions do not face each other, and the non-printed surfaces of the first and second regions that face each other are bonded together.
A capacitive touch switch characterized by being in an inward-folded state in which the printed surfaces of the second region and the third region face each other along the second fold line, the second region, the first region, and the third region are arranged in this order in the stacking direction, and the portions of the first region and the third region that face each other are bonded together. The capacitive touch switch according to claim 1 or 2, wherein an adhesive layer is formed between the non-printed surfaces of the first region and the second region that face each other in the outward-folded state, and the two regions are bonded together. A capacitive touch switch according to any one of claims 1 to 3 , wherein at least the first region has a terminal portion, and the terminal portion is provided with the ground portion by a printing process. A method for manufacturing a capacitive touch switch using a single thin-film substrate,
A printing step of printing at least a touch electrode and a ground portion, or a shield portion in addition to them, only on one side of the single substrate film, which is the printing surface,
A method for manufacturing a capacitive touch switch, characterized by forming adjacent first and second regions on a single base film with a predetermined first fold line as the boundary, forming a third region adjacent to the second region with a predetermined second fold line as the boundary, folding the film outwards along the first fold line so that the printed surfaces of the first and second regions do not face each other, arranging the second region, the first region, and the third region in this order in the stacking direction with the film outwards along the second fold line so that the printed surfaces of the second and third regions do not face each other, and bonding the non-printed surfaces of the first and second regions that face each other and the portions of the first and third regions that face each other. A method for manufacturing a capacitive touch switch using a single thin-film substrate,
A printing step of printing at least a touch electrode and a ground portion, or a shield portion in addition to them, only on one side of the single substrate film, which is the printing surface,
A method for manufacturing a capacitive touch switch, characterized by forming adjacent first and second regions on a single base film with a predetermined first fold line as the boundary, forming a third region adjacent to the second region with a predetermined second fold line as the boundary, folding the film outwards along the first fold line so that the printed surfaces do not face each other, and folding the film inwards along the second fold line so that the printed surfaces of the second and third regions face each other, arranging the second, first, and third regions in this order in the stacking direction, and then bonding the non-printed surfaces of the first and second regions that face each other and the portions of the first and third regions that face each other.