TWI575281B - Capacitive touch panel and manufacturing method thereof - Google Patents

Description

Capacitive touch panel and manufacturing method thereof

The present invention relates to a capacitive touch panel, and more particularly to a capacitive touch panel and a method of fabricating the same.

The capacitive touch panel is generally attached to the display, and the user can follow the indication of the display screen, and perform operations such as clicking and dragging on the touch panel to input commands.

A conventional capacitive touch panel is shown in FIG. 1. The sensing layer 12 includes a plurality of inductors disposed on the upper surface 142 of the substrate 14 in an optoelectronic process. The shielding layer 16 is plated on the lower surface 144 of the substrate 14. Insulating the noise interference of the sensing layer 12 and the lower display or circuit component (not shown), a Flexible Printed Circuit Assembly (FPCa) 18 is connected to the sensing layer 12 for processing the sensed signal, and then, for example, As shown in FIG. 2, the inner surface 104 of the protective layer 10 is bonded to the sensing layer 12 and the flexible printed circuit board 18 by the adhesive dielectric layer 20 to form a capacitive touch panel 22.

The protective layer 10 is used to protect the inductors in the sensing layer 12 and is operated by the user on the operating surface 102, and the substrate 14 is used to set the sensing layer 12 and the shielding layer 16. The protective layer 10 and the substrate 14 in the conventional capacitive touch panel are made of a hard glass material. Since the protective layer 10 and the substrate 14 are both hard plates, which is disadvantageous for adhesive bonding, a common problem such as occurrence of bubbles is difficult to remove. The hard board bonding process has high construction difficulty, low yield, and high cost. Therefore, the present invention provides a capacitive touch panel and a manufacturing method thereof, which avoids the hard board bonding process, reduces cost, and improves yield.

One of the objects of the present invention is to provide a capacitive touch panel.

One of the objects of the present invention is to provide a method of manufacturing a capacitive touch panel.

According to the present invention, a capacitive touch panel includes a protective layer having an operation surface and an inner surface. The sensing layer is disposed on an inner surface of the protective layer, and the adhesive dielectric layer adheres the sensing layer to a soft board coated with a conductive layer. .

According to the present invention, a method of manufacturing a capacitive touch panel includes providing a protective layer, disposing a sensing layer on an inner surface of the protective layer, providing a soft plate coated with a conductive layer, and bonding the soft plate and the sensing layer. An adhesive medium layer is formed between the flexible board and the sensing layer.

In an embodiment of the invention, the soft plate is realized by plating ITO or ZnO on a transparent insulating film.

In an embodiment of the invention, the first direction sensor, the wire and the second direction sensor are disposed on the same plane, the first direction sensors are connected by the wires, and the second direction sensors are crossed The first direction sensor or the conductive bridges of the wires are connected to achieve a thinned sensing layer.

3 and FIG. 4 are schematic diagrams showing a first embodiment of the capacitive touch panel of the present invention. The upper surface of the protective layer 30 is an operation surface 302 for the user to operate, and the sensing layer 32 is disposed on the protective layer 30 by a photoelectric process. The inner surface 304, the conductive layer 344 is plated on the soft board 34, and the flexible printed circuit board 36 is connected to the sensing layer 32 for processing the sensed signal. In the embodiment, the conductive layer 344 is indium tin oxide (ITO). Sputtering, coating, or printing is applied to the flexible board 34. Next, as shown in FIG. 4, the sensing layer 32 and the flexible printed circuit board 36 are adhered by the adhesive dielectric layer 38. The conductive layer 344 attached to the flexible board 34 and the soft board 34 provides a noise shielding function for the sensing layer 32. In other embodiments, conductive layer 344 can be implemented with zinc oxide (ZnO).

In different embodiments, a layer of anti-reflective or glare material may be formed on the soft board or the protective layer, so that the touch panel has the characteristics of preventing reflection or preventing glare to provide a better visual effect. Antireflection films are mostly optically designed using low refractive index SiOx (n=1.46) or polymer resin (n=1.42-1.46). Recently, due to the diversified development of materials, heterogeneous materials in which SiOx and resin are mixed are often used. . The deposition position of the anti-reflection film may have different anti-reflection effects depending on the deposition position on the operation surface 302, the inner surface 304 which is in contact with the finger, or on the soft board 34. The anti-glare material is generally an organic resin hybrid particle, which may be an organic or inorganic material, so that it effectively diffuses the incident light source, and therefore the anti-glare film should be deposited on the surface of the outermost layer, that is, the operation surface 302. Anti-reflective film and anti-glare film can be used at the same time. Proper combination can not only increase the brightness of the backlight, but also reduce the reflection of the external light source, improving visibility and clarity.

In the present embodiment, the flexible board 34 is a transparent insulating film having a certain thickness separating the sensing layer 32 and the conductive layer 344, so that the capacitance value formed therebetween is reduced to avoid affecting the sensing layer 32. One way of performing the adhesive bonding may be to gradually laminate the soft board 34 to the sensing layer 32 in a crimped manner, which requires low precision, high yield, and low cost. Wherein, the adhesive dielectric layer 38 can be realized by a transparent optical glue (Optical Glue) or an optically clear adhesive (OCA) with good insulating ability.

Referring to FIG. 2 , the sensing layer 12 and the shielding layer 16 of the conventional touch panel 20 are disposed on the upper and lower surfaces of the substrate 14 , so that the supporting force required by the substrate 14 is high, and the sensing layer 32 of the present invention is instead disposed on the protective layer 30 . The inner surface reduces the support required for the soft board 34.

5 is a top view of a second embodiment of a capacitive touch panel according to the present invention, the sensing layer disposed under the protective layer 50 includes a first direction trace 52 and a second direction trace 54, and FIG. 6 is a broken line in FIG. In the cross-sectional view of the circle, in order to explain the order of setting the sensing layer, FIG. 6 shows the protective layer 50 below.

First, a first direction sensor 522, a wire 524 and a second direction sensor 542 are disposed on the inner surface of the protective layer 50. Then, a dielectric layer 60 is formed and etched to expose a portion of the second direction sensor 542. To form a conductive pillar 546, finally, a conductive plate 545 is formed on the dielectric layer 60 and the conductive pillar 546. The conductive plate 545 and the conductive pillar 546 form a conductive bridge 544, and the conductive bridge 544 spans the wire 524 of the first direction trace 52, so that The adjacent second direction sensors 542 are electrically connected to each other to form a second direction trace 54 to complete the setting of the sensing layer 56. Since the first direction sensor 522 and the second direction sensor 542 are both disposed on the same plane, the sensing layer of the present embodiment can be thinner than the conventional two-layer architecture. After the sensing layer 56 is disposed, the dielectric layer 64 is formed thereon, and the sensing layer 56 and the flexible printed circuit board 36 are adhered to the flexible board 34 coated with the conductive layer 344 by the adhesive medium layer 38.

Figure 7 is a cross-sectional view showing a third embodiment of the present invention. Referring to Figure 5, a conductive plate 547 is first disposed on the inner surface of the protective layer 50, and a dielectric layer 62 is formed and etched to expose a portion of the conductive plate 547 for A conductive post 548 is formed to form a conductive bridge 544. Finally, a second direction sensor 542 is disposed on the dielectric layer 62 and the conductive post 548, and then disposed on the second direction sensor 542, the first direction sensor 522, and the wire 524. The dielectric layer 64, wherein the adjacent second direction sensors 542 are electrically connected by the conductive bridge 544, constitutes the second direction trace 54 to complete the setting of the sensing layer 58. Similarly, the sensing layer 58 and the flexible printed circuit board 36 are adhered to the flexible board 34 by the adhesive medium layer 38.

In the foregoing embodiment, the conductive bridge 544 electrically connects the adjacent second direction sensors 542 to each other across the wires 524. In other embodiments, the first direction trace 52 and the second direction trace 54 may change the arrangement of the inductors according to application requirements, and the conductive bridge 544 may also sense the adjacent second direction across the first direction sensor 522. The device 542 is electrically connected.

Alternatively, the conductive bridge 544 can electrically connect two or more non-adjacent second direction sensors 542 in the second direction.

8 is a cross-sectional view of a fourth embodiment of a capacitive touch panel of the present invention, a first direction trace layer 72 including a plurality of first direction traces disposed on an inner surface of the protective layer 50, including a plurality of second directions The second direction trace layer 78 of the trace is additionally disposed on the second flexible board 76. The second adhesive medium layer 74 adheres the second flexible board 76 and the first direction trace layer 72 to form the sensing layer 70. The flexible board 34 coated with the conductive layer 344 is adhered to the second direction trace layer 78 and the flexible printed circuit board 36 by the adhesive medium layer 38.

9 is a cross-sectional view showing a fifth embodiment of the capacitive touch panel of the present invention, in which a first direction trace layer 72 including a plurality of first direction traces is disposed on the inner surface of the protective layer 50, and an insulating layer 79 is formed by photoelectric technology. Directly growing on the first direction trace layer 72, and then forming a second direction trace layer 78 including a plurality of second direction traces on the insulating layer 79, forming the sensing layer 80, and the soft board coated with the conductive layer 344 34 adheres to the second direction trace layer 78 and the flexible printed circuit board 36 with the adhesive dielectric layer 38.

The above description of the preferred embodiments of the present invention is intended to be illustrative, and is not intended to limit the scope of the invention to the disclosed embodiments. It is possible to make modifications or variations based on the above teachings or learning from the embodiments of the present invention. The embodiments are described and illustrated in the practical application of the present invention in various embodiments, and the technical idea of the present invention is intended to be equivalent to the scope of the following claims. Decide.

10. . . The protective layer

102. . . Operating surface

104. . . inside

12. . . Sensing layer

14. . . Substrate

142. . . Upper surface

144. . . lower surface

16. . . Shield

18. . . Flexible printed circuit board

20. . . Adhesive dielectric layer

twenty two. . . Capacitive touch panel

30. . . The protective layer

302. . . Operating surface

304. . . inside

32. . . Sensing layer

34. . . Soft board

344. . . Conductive layer

36. . . Flexible printed circuit board

38. . . Adhesive dielectric layer

50. . . The protective layer

502. . . Operating surface

52. . . First direction trace

522. . . First direction sensor

524. . . wire

54. . . Second direction trace

542. . . Second direction sensor

544. . . Conductive bridge

545. . . Conductive plate

546. . . Conductive column

547. . . Conductive plate

548. . . Conductive column

56. . . Sensing layer

58. . . Sensing layer

60. . . Dielectric layer

62. . . Dielectric layer

64. . . Dielectric layer

70. . . Sensing layer

72. . . First direction trace layer

74. . . Second adhesive medium layer

76. . . Second soft board

78. . . Second direction trace

79. . . Insulation

80. . . Sensing layer

1 and 2 are schematic views of a conventional touch panel;

3 and 4 are schematic views of a first embodiment of a touch panel of the present invention;

Figure 5 is a top plan view of a second embodiment of a capacitive touch panel in accordance with the present invention;

Figure 6 is a cross-sectional view showing the dotted circle of Figure 5;

7 is a cross-sectional view showing a third embodiment of the capacitive touch panel of the present invention;

Figure 8 is a cross-sectional view showing a fourth embodiment of the capacitive touch panel of the present invention;

Figure 9 is a cross-sectional view showing a fifth embodiment of the capacitive touch panel of the present invention.

30. . . The protective layer

302. . . Operating surface

32. . . Sensing layer

34. . . Soft board

344. . . Conductive layer

36. . . Flexible printed circuit board

38. . . Adhesive dielectric layer

Claims (26)

A capacitive touch panel includes: a protective layer having an operation surface and an inner surface, wherein the operation surface is for a user to operate; a sensing layer disposed on an inner surface of the protective layer; a soft board; and a bonding medium layer The flexible board is adhered to the sensing layer. The capacitive touch panel of claim 1, wherein the material of the protective layer comprises glass. The capacitive touch panel of claim 1, wherein the flexible board is a transparent insulating film. The capacitive touch panel of claim 1, wherein the flexible board is plated with a conductive layer. The capacitive touch panel of claim 4, wherein the conductive layer is sputtered on the flexible board. The capacitive touch panel of claim 4, wherein the conductive layer comprises indium tin oxide or zinc oxide. The capacitive touch panel of claim 1, wherein the adhesive medium layer comprises an optical water gel or an optical transparent adhesive. The capacitive touch panel of claim 1, wherein the adhesive dielectric layer is an insulator. The capacitive touch panel of claim 1 further comprises a flexible printed circuit board connected to the sensing layer for processing the signal sensed by the sensing layer, and the bonding layer is adhered to the flexible board. The capacitive touch panel of claim 1, wherein the sensing layer comprises: a first direction trace comprising a first direction sensor and a wire; and a second direction trace comprising a second direction sensor and a conductive bridge; The conductive bridge bridges the first direction trace and electrically connects the second direction sensors in a second direction. The capacitive touch panel of claim 10, wherein the first direction sensor, the guide The line and the second direction sensor are located on the same plane. The capacitive touch panel of claim 11, wherein the first direction sensor, the wire and the second direction sensor are disposed on an inner surface of the protective layer. The capacitive touch panel of claim 11, wherein the conductive bridge is disposed on an inner surface of the protective layer. The capacitive touch panel of claim 10, wherein the conductive bridge comprises: a conductive plate; and a conductive post connecting the conductive plate and the second direction sensor. The capacitive touch panel of claim 1, wherein the sensing layer comprises: a first direction trace layer disposed on an inner surface of the protection layer; and a second flexible board on which a second direction trace layer is disposed; The second adhesive medium layer adheres the second flexible board to the first direction trace layer. The capacitive touch panel of claim 15, wherein the second flexible board is a transparent insulating film. The capacitive touch panel of claim 1, wherein the flexible board has an anti-reflective film. The capacitive touch panel of claim 1, wherein the sensing layer comprises: a first direction trace layer disposed on an inner surface of the protective layer; and an insulating layer formed on the first trace layer by a photoelectric process; And a second direction trace layer formed on the insulating layer by a photoelectric process. A method of manufacturing a capacitive touch panel, comprising the steps of: providing a protective layer; disposing a sensing layer on an inner surface of the protective layer; providing a soft board; The flexible board and the sensing layer are bonded to form an adhesive medium layer between the flexible board and the sensing layer. The manufacturing method of claim 19, wherein the step of providing the flexible board comprises providing the soft board plated with a conductive layer. The method of claim 20, wherein the step of providing a soft plate coated with a conductive layer comprises sputtering the conductive layer on a lower surface of the flexible board. The manufacturing method of claim 19, wherein the step of disposing the sensing layer on the inner surface of the protective layer comprises: providing a plurality of first direction sensors, a plurality of wires, and a plurality of second direction sensors on the inner surface of the protective layer The first direction sensors are electrically connected by the wires in a first direction; a dielectric layer is formed on the first direction inductors, the wires and the second direction sensors; and A plurality of conductive bridges are disposed on the electrical layer; wherein the conductive bridge bridges the first direction inductor or the wire, and the second direction sensors are electrically connected to each other in the second direction. The manufacturing method of claim 22, wherein the first direction sensors, the wires, and the second direction sensors are in the same plane. The manufacturing method of claim 19, wherein the step of disposing the sensing layer on the inner surface of the protective layer comprises: forming a conductive bridge and a dielectric layer on the inner surface of the protective layer; and setting the conductive bridge and the dielectric layer a plurality of first direction sensors, a plurality of wires, and a plurality of second direction sensors, wherein the first direction sensors are electrically connected by the wires in a first direction; The second direction sensors are electrically connected by the conductive bridge in the second direction. The manufacturing method of claim 24, wherein the first direction sensors, the wires, and the second direction sensors are in the same plane. The manufacturing method of claim 19, wherein the step of disposing the sensing layer on the inner surface of the protective layer comprises: providing a first direction trace layer on an inner surface of the protective layer; and providing a second trace layer in the second direction And forming a second adhesive medium layer between the second flexible board and the first direction trace layer; and bonding the second flexible board and the first direction trace layer.