JP2018005699A - Touch panel and touch panel manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a touch panel and a touch panel manufacturing method that can avoid the occurrence of short circuit between electrodes due to an etching failure.SOLUTION: A touch panel 21 includes: a substrate 22; a reception side transparent electrode 23 and a transmission side transparent electrode 24 formed on the substrate 22; an insulation layer 28 formed between the reception side transparent electrode 23 and transmission side transparent electrode 24; and insulation layers 33 formed on the reception side transparent electrode 23, transmission side transparent electrode 24 and insulation layer 28. In addition, before forming the reception side transparent electrode 23 and transmission side transparent electrode 24, the insulation layer 28 is formed between positions where the reception side transparent electrode 23 and transmission side transparent electrode 24 are formed.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a touch panel and a method for manufacturing a touch panel.

  Conventionally, a capacitive touch panel that can detect the position of a finger based on a change in capacitance is known (see, for example, Patent Document 1).

  FIG. 1 is a schematic configuration diagram of a conventional capacitive touch panel. In the touch panel 1, a reception-side transparent electrode 3 and a transmission-side transparent electrode 4 are formed on a glass substrate 2. The reception-side transparent electrode 3 and the transmission-side transparent electrode 4 are formed of the same conductive film (for example, an ITO (Indium Tin Oxide) film), but are electrically insulated from each other. The plurality of receiving-side transparent electrodes 3 arranged in a row (on the vertical line) are electrically connected to each other. The plurality of transmission-side transparent electrodes 4 arranged on one line (on the horizontal line) are electrically connected to each other. The receiving-side transparent electrodes 3 at both ends of each row are connected to a flexible printed circuit (FPC) 5 via wiring 6. In addition, the transmission-side transparent electrodes 4 at both ends of each row are connected to the FPC 5 via the wiring 6.

  2A and 2B are diagrams showing a process of forming the region 7 of the touch panel of FIG. FIG. 2C is a cross-sectional view taken along the line AA in FIGS.

  FIG. 2A shows a case where the bridge layer 10 that connects adjacent transmission-side transparent electrodes 4 is disposed below the insulating layer 11, and the reception-side transparent electrode 3 is disposed on the insulating layer 11. FIG. 2B shows a case where the bridge layer 10 that connects adjacent transmission-side transparent electrodes 4 is disposed on the insulating layer 11, and the reception-side transparent electrode 3 is disposed below the insulating layer 11. The touch panel region 7 is created by either the method shown in FIG. 2A or 2B.

  In FIG. 2A, first, a bridge layer 10 for connecting adjacent transmission-side transparent electrodes 4 is formed on the glass substrate 2 (S1A). Next, the insulating layer 11 is formed on the bridge layer 10 so as to cover the bridge layer 10 (S2A). At this time, both ends of the bridge layer 10 are exposed to connect to the transmission-side transparent electrode 4. Next, the transmission-side transparent electrode 4 is formed on both ends of the bridge layer 10 and the reception-side transparent electrode 3 is formed on the glass substrate 2 so as not to overlap the transmission-side transparent electrode 4 through the gap 12 ( S3A). A connecting portion 3 a that connects adjacent receiving-side transparent electrodes 3 is formed on the insulating layer 11 so as to intersect the insulating layer 11 in a top view. Finally, the insulating layer 13 is formed on the entire upper surface of the transmitting transparent electrode 4, the receiving transparent electrode 3, the glass substrate 2 (that is, the glass substrate 2 at a position corresponding to the gap 12), and the insulating layer 11 (S4A). ). The insulating layer 13 is indicated by a dotted line.

  In FIG. 2B, first, the reception-side transparent electrode 3 and the transmission-side transparent electrode 4 are formed on the glass substrate 2 so as not to overlap each other via the gap 12 (S1B). Next, the insulating layer 11 is connected to the transmission-side transparent electrode 4 and the glass substrate 2 corresponding to the transmission-side transparent electrode 4, the connection portion 3 a, and the gap 12 so as to intersect the connection portion 3 a in a top view. Formed on (S2B). Thereafter, the bridge layer 10 is formed on the insulating layer 11 so that both ends thereof are connected to the transmission-side transparent electrode 4 (S3B). Finally, the insulating layer 13 is formed on the entire upper surface of the transmitting side transparent electrode 4, the receiving side transparent electrode 3, the glass substrate 2 (that is, the glass substrate 2 at a position corresponding to the gap 12), the insulating layer 11, and the bridge layer 10. (S4B). The insulating layer 13 is indicated by a dotted line.

  As shown in FIG. 2C, in the cross section taken along line AA, the reception-side transparent electrode 3 and the transmission-side transparent electrode 4 are formed on the glass substrate 2, and the insulating layer 13 is formed of the reception-side transparent electrode 3 and the transmission. It is formed on the side transparent electrode 4 and the glass substrate 2.

JP 2010-191797 A

  By the way, in the step of forming the reception side transparent electrode 3 and the transmission side transparent electrode 4 of S3A and S1B on the glass substrate 2, the transparent electrode layer 15 is once formed on the glass substrate 2, and the resist pattern 16 is transparent. It is formed on the electrode layer 15 (see FIG. 3). The resist pattern 16 is not formed at a position corresponding to the gap 12. Thereafter, the transparent electrode layer 15 is etched and the resist pattern 16 is removed, whereby the reception-side transparent electrode 3 and the transmission-side transparent electrode 4 are formed.

  At this time, the receiving-side transparent electrode 3 and the transmitting-side transparent electrode 4 may be connected (that is, a short circuit occurs) due to an etching error. This problem is more likely to occur as the thickness of the transparent electrode layer 15 increases, and thus becomes a serious problem in a large-sized touch panel that needs to reduce the circuit resistance. Further, this problem is likely to occur when the distance between the reception-side transparent electrode 3 and the transmission-side transparent electrode 4 is narrow.

  An object of the present invention is to provide a touch panel and a touch panel manufacturing method capable of avoiding occurrence of a short circuit between electrodes due to an etching error.

  In order to achieve the above object, a touch panel disclosed in the specification is formed between a substrate, a first electrode and a second electrode formed on the substrate, and the first electrode and the second electrode. A first insulating layer, and a second insulating layer formed on the first electrode, the second electrode, and the first insulating layer.

  In order to achieve the above object, a touch panel manufacturing method disclosed in the specification forms a first insulating layer between a position on a substrate where a first electrode is formed and a position where a second electrode is formed. Then, after forming the first insulating layer, the first electrode and the second electrode are formed on the substrate, and a second insulating layer is formed on the first electrode, the second electrode, and the first insulating layer. It is characterized by doing.

  According to the present invention, it is possible to avoid the occurrence of a short circuit between electrodes due to an etching error.

It is a schematic block diagram of the conventional capacitive touch panel. (A), (B) is a figure which shows the formation process of the area | region 7 of the touchscreen of FIG. (C) is sectional drawing of the AA line of FIG. 2 (A), (B). It is explanatory drawing of the process of forming a receiving side transparent electrode and a transmitting side transparent electrode on a glass substrate. It is a schematic block diagram of the touchscreen which concerns on this Embodiment. (A) is a figure which shows the formation process of the area | region 27 of the touchscreen of FIG. (B) is sectional drawing of the AA line of FIG. 5 (A). (C) is a figure which shows the other formation process of the area | region 27 of the touchscreen of FIG. (D) is sectional drawing of the AA line of FIG.5 (C). (E) is sectional drawing of the BB line of FIG. 5 (A), (C). It is a figure which shows the formation process of the laminated structure of the cross section of the BB line of FIG. 5 (A), (C). (A), (B) is a figure explaining the principle of operation of a touch panel. It is a figure which shows the relationship between the capacity | capacitance component C detected by the controller, and time t. (A) is a figure which shows roughly an amplification factor in case the capacity | capacitance component C1 is large. (B) is a figure which shows the state which amplifies a delta value according to the amplification factor of FIG. 9 (A). (C) is a figure which shows roughly an amplification factor in case the capacity | capacitance component C1 is small. (D) is a figure which shows the state which amplifies a delta value according to the amplification factor of FIG.9 (C).

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 4 is a schematic configuration diagram of the touch panel according to the present embodiment. The touch panel 21 according to the present embodiment is a capacitive touch panel. In the touch panel 21, a reception-side transparent electrode 23 and a transmission-side transparent electrode 24 are formed on the same plane on the glass substrate 22. One of the reception-side transparent electrode 23 and the transmission-side transparent electrode 24 functions as a first electrode, and the other functions as a second electrode. The reception-side transparent electrode 23 and the transmission-side transparent electrode 24 are formed of the same conductive film (for example, an ITO (Indium Tin Oxide) film), but are electrically insulated from each other. The plurality of receiving-side transparent electrodes 23 arranged in a line (on the vertical line) are electrically connected to each other. The plurality of transmission-side transparent electrodes 24 arranged in a row (on the horizontal line) are electrically connected to each other. The receiving-side transparent electrodes 23 at both ends of each column are connected to a flexible printed circuit (FPC) 25 via a wiring 26. Further, the transmission-side transparent electrodes 24 at both ends of each row are connected to the FPC 25 via the wiring 26.

  An insulating layer 28 as a first insulating layer is formed between the receiving-side transparent electrode 23 and the transmitting-side transparent electrode 24 on the glass substrate 22. The insulating layer 28 is formed on the glass substrate 22 in advance before the reception-side transparent electrode 23 and the transmission-side transparent electrode 24 are formed.

  FIG. 5A is a diagram illustrating a process of forming the region 27 of the touch panel in FIG. FIG. 5B is a cross-sectional view taken along line AA in FIG. FIG. 5C is a diagram showing another formation process of the region 27 of the touch panel of FIG. FIG. 5D is a cross-sectional view taken along line AA in FIG. FIG. 5E is a cross-sectional view taken along line BB in FIGS. 5A and 5C.

  5A and 5B, the bridge layer 30 that connects adjacent transmission-side transparent electrodes 24 is disposed below the insulating layer 31, and the reception-side transparent electrode 23 is disposed on the insulating layer 31. Show the case. 5C and 5D, the bridge layer 30 that connects the adjacent transmission-side transparent electrodes 24 is disposed on the insulating layer 31, and the reception-side transparent electrode 23 is disposed below the insulating layer 31. Show the case. The touch panel region 27 is created by one of the methods shown in FIGS. 5A and 5C.

  The insulating layer 31 is a layer for insulating the bridge layer 30 that connects adjacent transmission-side transparent electrodes 24 from the reception-side transparent electrode 23. The insulating layer 33 as the second insulating layer is a layer formed on the receiving side transparent electrode 23 and the transmitting side transparent electrode 24 in order to protect the receiving side transparent electrode 23 and the transmitting side transparent electrode 24.

  5A and 5B, first, a bridge layer 30 for connecting adjacent transmission-side transparent electrodes 24 is formed on the glass substrate 22 (S11A). Next, the insulating layer 31 is formed on the bridge layer 30 so as to cover the bridge layer 30, and the insulating layer 28 is positioned between the positions on the glass substrate 22 where the reception-side transparent electrode 23 and the transmission-side transparent electrode 24 are formed. (S12A). That is, in S12A, the insulating layer 31 and the insulating layer 28 are formed simultaneously. The insulating layer 31 and the insulating layer 28 are made of the same material.

  Both ends of the bridge layer 30 are exposed for connection to the transmission-side transparent electrode 24. Next, the glass substrate 22 is formed such that the transmission-side transparent electrode 24 is formed on the glass substrate 22 so as to cover both ends of the bridge layer 30, and the reception-side transparent electrode 23 and the transmission-side transparent electrode 24 sandwich the insulating layer 28. It is formed on (S13A). At this time, the connecting portion 23 a that connects the adjacent reception-side transparent electrodes 23 is formed on the insulating layer 31 so as to intersect the insulating layer 31 in a top view. Finally, the insulating layer 33 is formed on the entire upper surface of the transmission-side transparent electrode 24, the reception-side transparent electrode 23, and the insulating layer 28 (S14A).

  5C and 5D, first, the insulating layer 28 is formed between positions on the glass substrate 22 where the reception-side transparent electrode 23 and the transmission-side transparent electrode 24 are formed (S11B). Next, the reception-side transparent electrode 23 and the transmission-side transparent electrode 24 are formed on the glass substrate 22 so as to sandwich the insulating layer 28 (S12B).

  Next, the insulating layer 31 is formed on the connecting portion 23a and the insulating layer 28 adjacent to both sides of the connecting portion 23a (S13B). Further, the bridge layer 30 is formed on the insulating layer 31 so that both ends of the bridge layer 30 are connected to the adjacent transmission-side transparent electrodes 24 (S14B). Finally, the insulating layer 33 is formed on the entire top surface of the transmitting-side transparent electrode 24, the receiving-side transparent electrode 23, the insulating layer 28, the insulating layer 31, and the bridge layer 30 (S15B).

  As shown in FIG. 5E, in the cross section taken along line BB, the reception-side transparent electrode 23 and the transmission-side transparent electrode 24 are formed on the glass substrate 22, and the insulating layer 28 is formed on the reception-side transparent electrode 23 and the transmission side. An insulating layer 33 is formed between the transparent electrodes 24, and is formed on the reception-side transparent electrode 23, the transmission-side transparent electrode 24, and the insulating layer 28.

  FIG. 6 is a diagram showing a step of forming a laminated structure of the cross section taken along line BB in FIGS. 5 (A) and 5 (C). First, the insulating layer 28 is formed on the glass substrate 22 by sputtering (S21). Further, the transparent conductive layer 35 is formed by sputtering on the glass substrate 22 on which the insulating layer 28 is formed (S22). The transparent conductive layer 35 finally becomes the reception-side transparent electrode 23 and the transmission-side transparent electrode 24.

  Further, a resist pattern 36 is formed on the transparent conductive layer 35 (S23). At this time, the resist pattern 36 is not formed on the transparent conductive layer 35 on the insulating layer 28. Thereafter, the transparent conductive layer 35 on which the resist pattern 36 is not formed is etched and the resist pattern 36 is removed, thereby forming the reception-side transparent electrode 23 and the transmission-side transparent electrode 24 (S24). Thereafter, the insulating layer 33 is formed on the receiving side transparent electrode 23, the transmitting side transparent electrode 24, and the insulating layer 28 by sputtering (S25).

  As described above, the insulating layer 28 is formed between the reception side transparent electrode 23 and the transmission side transparent electrode 24 before the reception side transparent electrode 23 and the transmission side transparent electrode 24 are formed. Occurrence of a short circuit between the electrodes can be avoided.

  7A and 7B are diagrams for explaining the operation principle of the touch panel 21. FIG. FIG. 7A shows a non-touch state, and FIG. 7B shows a touch state.

  In the capacitive touch panel 21, the controller 50 applies a pulse signal to the transmission-side transparent electrode 24, detects a change in capacitance when a finger touches the insulating layer 33, and determines whether or not there is a touch. Is going.

  The capacitance component C detected by the controller 50 is between the capacitance component C1 created by the electric lines of force 41 between the transmission-side transparent electrode 24 and the reception-side transparent electrode 23, and between the transmission-side transparent electrode 24 and the reception-side transparent electrode 23. The total value with the capacitance component C2 generated by the electric field lines 42 (C = C1 + C2). The capacitive component C1 is a parasitic capacitance that does not contribute to finger detection. The capacitance component C2 is a capacitance that contributes to finger detection. In general, the capacitive component C1 is larger than the capacitive component C2.

  FIG. 8 is a diagram showing the relationship between the capacitance component C detected by the controller 50 and the time t. The controller 50 detects the delta value (that is, the amount of change) of the capacitive component C (= C1 + C2) before and after the touch, and detects the touch of the finger on the touch panel 21 when the delta value is larger than a preset threshold value. . However, since the delta value is very small, the controller 50 amplifies and detects the delta value. The controller 50 can amplify the capacitive component C to a predetermined amplification limit value.

  FIG. 9A is a diagram schematically showing the amplification factor when the capacitance component C1 is large. FIG. 9B is a diagram illustrating a state in which the delta value is amplified according to the amplification factor of FIG. FIG. 9C is a diagram schematically showing the amplification factor when the capacitance component C1 is small. FIG. 9D is a diagram illustrating a state in which the delta value is amplified according to the amplification factor of FIG.

  When the capacitance component C1 is large, the amplification factor of the capacitance component C is small, so the amplification factor of the delta value is also small. For example, as shown in FIG. 9A, when the amplification factor of the capacitive component C is X1, the amplified delta value is X1 times the delta value before amplification, as shown in FIG. 9B. is there. On the other hand, when the capacitance component C1 is small, the amplification factor of the capacitance component C is large, so that the amplification factor of the delta value is also large. For example, as shown in FIG. 9C, when the amplification factor of the capacitive component C is X2 times larger than X1, the delta value after amplification is the delta value before amplification as shown in FIG. 9D. It is X2 times.

  Therefore, by reducing the capacitance component C1, the amplification factor of the delta value can be increased, and the touch detection sensitivity can be improved. Further, by increasing the capacitance component C2 itself that contributes to finger detection, it is possible to improve touch detection sensitivity.

  In order to reduce the capacitance component C1, it is conceivable to increase the distance between the transmission-side transparent electrode 24 and the reception-side transparent electrode 23 (that is, the width d of the insulating layer 28 in FIG. 7A). In this case, there is a problem that the patterns of the transmission-side transparent electrode 24 and the reception-side transparent electrode 23 are visible and the appearance is deteriorated.

  Therefore, in the present embodiment, the insulating layer 28 is formed of a low dielectric constant material. That is, the insulating layer 28 is formed of a material having a dielectric constant lower than that of at least the insulating layer 33. As described above, the insulating layer 28 is formed of an insulating material different from that of the insulating layer 33. When a material having a low dielectric constant is used as the insulating layer 28, the electric force lines 41 in FIG. 7A are attenuated, so that the capacitance component C1 (parasitic capacitance) can be reduced.

  Further, in the present embodiment, the insulating layer 33 is formed of a high dielectric constant material in order to increase the capacitance component C2. That is, the insulating layer 33 is formed of a material having a dielectric constant higher than that of at least the insulating layer 28. When a material having a high dielectric constant is used as the insulating layer 33, the electric lines of force 42 in FIG. 7A are enhanced (that is, the capacitance component C2 itself that contributes to finger detection increases). Detection sensitivity can be improved.

  In the present embodiment, the insulating layer 28 is, for example, an acrylic resin having a dielectric constant of 2.7 to 3.0, and the insulating layer 33 is, for example, silicon oxide (SiO 2) having a dielectric constant of 4.0, or For example, silicon nitride (SiN) having a dielectric constant of 6.0.

  In the present embodiment, the insulating layer 28 preferably has optical characteristics equivalent to those of the transmission-side transparent electrode 24 and the reception-side transparent electrode 23. That is, the insulating layer 28 is preferably formed of a transparent material and a material having a refractive index equivalent to that of the transmission-side transparent electrode 24 and the reception-side transparent electrode 23. This is to prevent the insulating layer 28 from being seen by the operator from the operation surface side, that is, to prevent the appearance from deteriorating.

  As described above, according to the present embodiment, before the reception-side transparent electrode 23 and the transmission-side transparent electrode 24 are formed, between the positions where the reception-side transparent electrode 23 and the transmission-side transparent electrode 24 are formed. Since the insulating layer 28 is formed in this manner, it is possible to avoid the occurrence of a short circuit between the electrodes due to an etching error.

  The present invention is not limited to the above-described embodiment, and can be implemented with various modifications within a range not departing from the gist thereof.

21 Touch Panel 22 Substrate 23 Reception-side Transparent Electrode 24 Transmission-side Transparent Electrode 25 FPC
26 Wiring 28, 31, 33 Insulating layer 30 Bridge layer

Claims (4)

A substrate,
A first electrode and a second electrode formed on the substrate;
A first insulating layer formed between the first electrode and the second electrode;
A touch panel comprising: the first electrode, the second electrode, and a second insulating layer formed on the first insulating layer.   The touch panel as set forth in claim 1, wherein the first insulating layer has a lower dielectric constant than the second insulating layer. Forming a first insulating layer between a position where the first electrode is formed on the substrate and a position where the second electrode is formed;
Forming the first electrode and the second electrode on the substrate after forming the first insulating layer;
A method for manufacturing a touch panel, wherein a second insulating layer is formed on the first electrode, the second electrode, and the first insulating layer. When forming the first electrode and the second electrode on the substrate, after forming the first insulating layer, an electrode film is formed on the substrate and the first insulating layer,
Forming a resist pattern on a portion of the electrode film that becomes the first electrode and the second electrode;
The method for manufacturing a touch panel according to claim 3, wherein the electrode film on the first insulating layer is etched to remove the resist pattern.

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