Touch assembly

Abstract

A touch assembly includes a protective cover, a first adhesive layer, a conductive layer, a second adhesive layer, and a flexible circuit board. The protective cover includes a visible area and a peripheral area. The first adhesive layer is disposed in the visible area. The conductive layer includes a plurality of bent conductive lines disposed on the first adhesive layer. The bent conductive lines include a first group of conductive lines and a second group of conductive lines overlapping the first group of conductive lines. Each bent conductive line includes a conductive core and an outer cover layer. The second adhesive layer covers the bent conductive lines and the first adhesive layer. The flexible circuit board includes a plurality of bonding pads. Each bent conductive line extends from the visible area to the peripheral area to form a signal transmission path. The signal transmission path includes a trace segment and a bonding segment. The trace segment extends in the length direction. The bonding segment bends repeatedly within a certain range in the width direction and engages with a corresponding bonding pad.

Description

Technical Field

[0001] This disclosure pertains to a touch assembly. Prior Technology

[0002] With the diversified development of touch modules, they have been successfully applied in industrial and consumer electronics products. Touch products integrated with various medium-to-large-sized devices will become increasingly common.

[0003] However, a conventional process for manufacturing touch modules currently uses indium tin oxide (ITO) as the transparent electrode. ITO production requires the rare metal indium. Indium reserves are limited, and its mining process causes environmental pollution. Furthermore, the aforementioned conventional process generates a large amount of ITO waste, which needs proper disposal to prevent further environmental pollution. Moreover, the conventional process requires high-temperature, high-pressure vacuum coating equipment, resulting in high energy consumption.

[0004] Therefore, how to propose a touch assembly that can solve the above problems is one of the issues that the industry is currently eager to address by investing research and development resources. Summary of the Invention

[0005] In view of this, one of the purposes of this disclosure is to propose a touch assembly that can solve the above problems.

[0006] To achieve the above objectives, according to one embodiment of this disclosure, a touch assembly includes a protective cover, a first adhesive layer, a conductive layer, a second adhesive layer, and a flexible circuit board. The protective cover includes a visible area and a peripheral area. The first adhesive layer is disposed in the visible area of ​​the protective cover. The conductive layer includes a plurality of bent conductive lines disposed on the first adhesive layer. The bent conductive lines include a first group of conductive lines extending along a first direction and a second group of conductive lines extending along a second direction and overlapping the first group of conductive lines. Each bent conductive line includes a conductive inner core and an outer cover layer. The conductive layer is used for touch sensing. The second adhesive layer covers the bent conductive lines and the first adhesive layer. The flexible circuit board includes a plurality of bonding pads. Each bent conductive line extends from the visible area to the peripheral area to form a signal transmission path. The signal transmission path includes a trace segment and a bonding segment. The trace segment extends in the length direction. The bonding segment bends back and forth within a certain range in the width direction and engages with a corresponding bonding pad.

[0007] In one or more embodiments disclosed herein, the joint section is repeatedly bent in a sawtooth shape.

[0008] In one or more embodiments disclosed herein, the engagement segment comprises a plurality of teeth connected in sequence. The included angle between adjacent teeth is approximately 10 degrees to approximately 16 degrees.

[0009] In one or more embodiments disclosed herein, the engaging segment comprises a plurality of teeth sequentially connected. The number of teeth is approximately 4 to approximately 6.

[0010] In one or more embodiments disclosed herein, the engagement segment comprises a plurality of teeth sequentially connected. The teeth are inclined to the same side relative to the width direction. Each tooth comprises two connected bevels. The longest of the bevels of the teeth has a length of about 0.5 mm to about 1.1 mm.

[0011] In one or more embodiments disclosed herein, the junction segments of two adjacent signal transmission paths are misaligned in the length direction.

[0012] In one or more embodiments disclosed herein, the mating pads are arranged in at least one row.

[0013] In one or more embodiments disclosed herein, each mating pad has a pointed tip.

[0014] In one or more embodiments disclosed herein, each bonding pad has a width of about 0.3 mm to about 0.7 mm and a length of about 0.1 mm to about 6 mm. The spacing between adjacent bonding pads is about 0.3 mm to about 1.1 mm.

[0015] In one or more embodiments disclosed herein, the thickness of the metal layer on the bonding pad is from about 3 µm to about 11 µm.

[0016] In summary, in the touch assembly disclosed herein, by employing a routing design where the junction segments of the bent conductors formed in the peripheral area repeatedly bend within a certain width direction, the conductive area between the junction segments and the bonding pads of the flexible circuit board can be increased. This not only effectively improves the process yield for laser soldering the junction segments and bonding pads (especially small-to-medium-sized bonding pads) of the bent conductors, but also effectively solves the peeling problem that easily occurs when using Chip on Film (COF) technology.

[0017] The above description is only used to illustrate the problem to be solved by this disclosure, the technical means to solve the problem, and the effects produced, etc. The specific details of this disclosure will be described in detail in the following implementation methods and related figures. Simple Explanation of the Diagram

[0018] To make the above and other objects, features, advantages and embodiments of this disclosure more apparent and understandable, the accompanying drawings are described below: Figure 1 is a schematic diagram illustrating a touch assembly according to one embodiment of the present disclosure. Figure 2 is a partial cross-sectional view showing some of the components in Figure 1. Figure 3 is a flowchart illustrating a method for manufacturing a touch assembly according to an embodiment of the present disclosure. Figure 4 is a flowchart illustrating a method for manufacturing a touch assembly according to another embodiment of this disclosure. Figures 5A to 5J are schematic diagrams illustrating intermediate steps of a method for manufacturing a touch assembly according to one embodiment of the present disclosure. Figure 6 is a partial cross-sectional view illustrating Figure 5I. Figures 7A to 7H are schematic diagrams illustrating intermediate steps of a method for manufacturing a touch assembly according to one embodiment of the present disclosure. Figure 8 is a partial schematic diagram showing some of the components in Figure 1. Figure 9 is a partial schematic diagram illustrating the bonding pad and signal transmission path according to an embodiment of this disclosure. Figure 10 is a schematic diagram illustrating some of the bonding pads according to one embodiment of this disclosure. Implementation

[0019] The following drawings disclose several embodiments of this disclosure. For clarity, many practical details will be described in the following description. However, it should be understood that these practical details should not be used to limit this disclosure. That is, in some embodiments of this disclosure, these practical details are not essential. In addition, for the sake of simplicity, some conventional structures and components will be shown in the drawings in a simple schematic manner.

[0020] Please refer to Figures 1 and 2. Figure 1 is a schematic diagram illustrating a touch assembly 100 according to an embodiment of the present disclosure. Figure 2 is a partial cross-sectional view illustrating some of the components in Figure 1. As shown in Figures 1 and 2, in this embodiment, the touch assembly 100 includes a protective cover 110, a first adhesive layer 120, a conductive layer 13L, a second adhesive layer 140, and a flexible circuit board 150. The first adhesive layer 120 is disposed on the protective cover 110. Specifically, the first adhesive layer 120 is disposed in the visible area of ​​the protective cover 110 (see Figure 8 for reference). The conductive layer 13L includes a plurality of bent conductive lines 130 disposed on the first adhesive layer 120. The bent conductive lines 130 are disposed on the first adhesive layer 120 and include a first group of conductive lines G1 and a second group of conductive lines G2. The first group of conductive lines G1 extends along a first direction and is arranged at intervals. The second group of conductors G2 extends along the second direction and overlaps the first group of conductors G1, and is spaced apart. In some embodiments, the first direction and the second direction are perpendicular to each other, for example, the X-axis direction and the Y-axis direction. The conductor layer 13L is used for touch sensing. The second adhesive layer 140 covers the bent conductor 130 and the first adhesive layer 120. The flexible circuit board 150 is electrically connected to the bent conductor 130.

[0021] As shown in Figure 2, specifically, each bent conductor 130 includes a conductive inner core 131 and an outer sheath 132. The outer sheath 132 contains an insulating material. Therefore, the conductive inner cores 131 of the first group of conductors G1 and the second group of conductors G2 are electrically insulated from each other by the outer sheaths 132 of the first group of conductors G1 and the second group of conductors G2. In this way, touch signals (such as mutual capacitance sensing signals) between the first group of conductors G1 and the second group of conductors G2 can be transmitted to the flexible circuit board 150.

[0022] In this embodiment, each bent wire 130 is an enameled wire. Therefore, the bent wire 130 can be fabricated in the touch assembly 100 using a winding technique, thereby avoiding the high pollution and high energy consumption problems of the conventional complex process of using indium tin oxide (ITO) as a transparent electrode.

[0023] In practical applications, the bent conductor 130 can also be a combination of enameled wire and ITO transparent electrode. For example, one of the first group of conductors G1 and the second group of conductors G2 of the bent conductor 130 is enameled wire, while the other group of conductors G1 and the second group of conductors G2 is an ITO transparent electrode.

[0024] In some embodiments, the conductive core 131 of the bent wire 130 is made of silver, copper, aluminum, tungsten, or similar metals.

[0025] In some embodiments, the material of the conductive core 131 of the bent wire 130 includes a palladium-copper alloy, a silver-palladium-copper alloy, a molybdenum-rhenium alloy, an aluminum alloy, a nickel alloy, or a similar alloy.

[0026] In some embodiments, the material of the outer sheath 132 of the bent conductor 130 includes polyvinyl formal, polyurethane, polyamide, polyester, polyester-polyimide, polyamide-polyimide, or polyimide, but this disclosure is not limited thereto.

[0027] In some embodiments, the diameter of the conductive core 131 of the bent conductor 130 is in the range of 2 µm to 20 µm. Preferably, the diameter of the conductive core 131 is in the range of 2 µm to 5 µm to improve the visibility of the touch assembly 100. That is, the visibility of the bent conductor 130 can be reduced. In some embodiments, the thickness of the outer cover 132 of the bent conductor 130 is in the range of 1 µm to 3 µm. For example, in one embodiment, the diameter of the conductive core 131 is about 5 µm, and the thickness of the outer cover 132 is about 2 µm (i.e., the diameter of the bent conductor 130 is about 7 µm), but this disclosure is not limited thereto.

[0028] As shown in Figure 2, in this embodiment, the first adhesive layer 120 and the second adhesive layer 140 fill the gaps between the first group of conductors G1 and the second group of conductors G2. This eliminates the gaps created by indentations between the bent conductor 130 and the first and second adhesive layers 120 and 140, effectively reducing the visibility of the bent conductor 130 when viewed from the side of the second adhesive layer 140 (i.e., reducing the generation of shadows).

[0029] In some embodiments, at least one of the first adhesive layer 120 and the second adhesive layer 140 is an optical clear adhesive (OCA) layer or a liquid optical clear adhesive (LOCA) layer, but this disclosure is not limited thereto.

[0030] In some embodiments, the thickness of the second adhesive layer 140 is in the range of 25 µm to 150 µm. When the thickness of the second adhesive layer 140 is less than the lower limit of the aforementioned range, the aforementioned gaps are not easily eliminated completely; when the thickness of the second adhesive layer 140 is greater than the lower limit of the aforementioned range, it will lead to an increase in the overall size, weight and cost of the touch assembly 100.

[0031] Please refer to Figure 3 for a flowchart illustrating a method for manufacturing a touch assembly according to an embodiment of the present disclosure. As shown in Figure 3, and in conjunction with Figures 1 and 2, in this embodiment, the method for manufacturing the touch assembly includes steps S110 to S140.

[0032] Step S110: Attach the first adhesive layer 120 to the protective cover plate 110.

[0033] In some embodiments, step S110 is performed by continuously laminating the first adhesive layer 120 onto the protective cover plate 110 at about 130 degrees Celsius for about 40 minutes, but this disclosure is not limited thereto.

[0034] In some embodiments, a black matrix (BM) layer may be formed on the protective cover 110 before step S110. After step S110, the first adhesive layer 120 comes into contact with the black matrix layer.

[0035] Step S120: A plurality of bent wires 130 are provided on the first adhesive layer 120.

[0036] In some embodiments, step S120 may include: winding an enameled wire 130A (see Figures 5C and 7B) onto the first adhesive layer 120; and cutting the enameled wire 130A to form a bent conductor 130.

[0037] In some embodiments, the step of cutting the enameled wire 130A to form the bent conductor 130 is performed by a laser cutting process, but this disclosure is not limited thereto.

[0038] Step S130: Cover the curved wire 130 with the second adhesive layer 140 and the first adhesive layer 120.

[0039] In some embodiments, step S130 is performed by continuously laminating the second adhesive layer 140 onto the first adhesive layer 120 at about 130 degrees Celsius for about 40 minutes, but this disclosure is not limited thereto.

[0040] Step S140: Solder the flexible circuit board 150 to the bent wire 130.

[0041] In some embodiments, step S140 is performed by a laser welding process, but this disclosure is not limited thereto.

[0042] Please refer to Figure 4, which is a flowchart illustrating a method for manufacturing a touch assembly according to another embodiment of this disclosure. As shown in Figure 4, and in conjunction with Figures 1 and 2, in this embodiment, the method for manufacturing the touch assembly includes steps S210 to S240.

[0043] Step S210: A plurality of bent wires 130 are provided on the first adhesive layer 120.

[0044] In some embodiments, step S210 may include: winding an enameled wire 130A (see Figures 5C and 7B) onto the first adhesive layer 120; and cutting the enameled wire 130A to form a bent conductor 130.

[0045] Step S220: Cover the second adhesive layer 140 onto the bent wire 130 and the first adhesive layer 120.

[0046] In some embodiments, step S220 is performed by continuously laminating the second adhesive layer 140 onto the first adhesive layer 120 at about 130 degrees Celsius for about 40 minutes, but this disclosure is not limited thereto.

[0047] Step S230: Solder the flexible circuit board 150 to the bent wire 130.

[0048] In some embodiments, step S230 is performed by a laser welding process, but this disclosure is not limited thereto.

[0049] Step S240: Transfer the combination comprising the first adhesive layer 120, the bent wire 130, the second adhesive layer 140 and the flexible circuit board 150 onto the protective cover plate 110.

[0050] Compared to the embodiment shown in Figure 3, the embodiment shown in Figure 4 transfers the combination of the first adhesive layer 120, the bent wire 130 and the second adhesive layer 140 onto the protective cover plate 110 after the lamination process of the second adhesive layer 140. This effectively avoids the problem of the high temperature during the lamination process damaging the black matrix layer on the protective cover plate 110.

[0051] Please refer to Figures 5A to 5J. Figures 5A to 5J are schematic diagrams illustrating intermediate steps of a manufacturing method for a touch assembly according to one embodiment of this disclosure. This embodiment is a specific implementation of the manufacturing method shown in Figure 4, and will be described in detail below.

[0052] As shown in Figure 5A, in this step, release films RF1 and RF2 are respectively attached to the opposite sides of the first adhesive layer 120.

[0053] As shown in Figure 5B, this step follows the step shown in Figure 5A. In this step, the release film RF2 is peeled off, and then the embedded wire EW is placed on the surface of the first adhesive layer 120 where the release film RF2 was originally attached. The embedded wire EW can be wound onto the first adhesive layer 120 using a winding machine 910. The wound embedded wire EW is U-shaped, as shown in Figure 5B, but this disclosure is not limited to this.

[0054] As shown in Figure 5C, this step follows the step shown in Figure 5B. In this step, the enameled wire 130A is wound onto the first adhesive layer 120. The winding method is, for example, to wind the wire along a reciprocating, meandering path onto the first adhesive layer 120, such that the enameled wire 130A partially covers the embedded wire EW. Specifically, as shown in Figure 5C, the wound enameled wire 130A is arranged in a checkerboard pattern on the first adhesive layer 120, and the three edges of the checkerboard pattern overlap the embedded wire EW.

[0055] As shown in Figure 5D, this step follows the step shown in Figure 5C. In this step, a single enameled wire 130A is cut to form a plurality of bent conductors 130. Specifically, this step can be performed by peeling the embedded wire EW from the first adhesive layer 120, causing the enameled wire 130A to break and form the bent conductors 130. The mechanism of peeling the embedded wire EW to break the enameled wire 130A is similar to the disassembly of the outer packaging of a cigarette box. Compared to cutting the enameled wire 130A with a knife, this step does not leave knife marks on the first adhesive layer 120. Therefore, step S210 can be achieved by sequentially performing the steps shown in Figures 5B, 5C, and 5D.

[0056] In some embodiments, the diameter of the embedded wire EW is larger than that of the enameled wire 130A. This allows the thicker embedded wire EW to have greater tensile strength than the thinner enameled wire 130A, thus preventing the embedded wire EW from breaking during the process of peeling off the enameled wire 130A. In one embodiment, the diameter of the embedded wire EW is approximately 20 µm, while the diameter of the enameled wire 130A is approximately 5 µm, but this disclosure is not limited thereto.

[0057] As shown in Figure 5E, this step follows the step shown in Figure 5D. In this step, a water-based adhesive 140A is applied to the first adhesive layer 120 using an adhesive applicator 920. Specifically, the water-based adhesive 140A is applied to the outer edge of the first adhesive layer 120. In some embodiments, the water-based adhesive 140A is a light-curing adhesive. For example, a light-curing adhesive can harden after being exposed to ultraviolet light. Therefore, by simultaneously exposing the adhesive to light in this step, the water-based adhesive 140A applied to the outer edge of the first adhesive layer 120 can be hardened into an exterior wall.

[0058] As shown in Figure 5F, this step follows the step shown in Figure 5E. In this step, the adhesive 140A can be applied to the first adhesive layer 120 using the adhesive applicator 920 to cover the curved wire 130. That is, the adhesive 140A is applied and filled into the space within the aforementioned exterior wall in this step. In other embodiments, this step can also employ methods such as scraping, dotting, slittering, filling, or similar application techniques.

[0059] As shown in Figure 5G, this step follows the step shown in Figure 5F. In this step, the pressure plate 940 covers the water-based adhesive 140A, and the roller 950 rolls the pressure plate 940. Simultaneously, while being exposed to light in this step, the water-based adhesive 140A is hardened into a second adhesive layer 140 of uniform thickness.

[0060] As shown in Figure 5H, this step follows the step shown in Figure 5G. In this step, after the water-based adhesive 140A has hardened into the second adhesive layer 140, the pressure plate 940 can be removed. Therefore, step S220 can be achieved by sequentially performing the steps shown in Figures 5E, 5F, 5G, and 5H.

[0061] As shown in Figure 5I, this step follows the step shown in Figure 5H. In this step, the flexible circuit board 150 is soldered to the bent wire 130 (i.e., step S230).

[0062] Please refer to Figure 6, which is a partial cross-sectional view illustrating Figure 5I. As shown in Figure 6, a flexible circuit board 150 can be soldered to a bent conductor 130 using a soldering machine 930. The flexible circuit board 150 has bonding pads 151. The bonding pads 151 have a metal layer 152. For example, the metal layer 152 may contain tin, but this disclosure is not limited thereto. For example, the soldering machine 930 is a laser soldering machine. The laser can penetrate the first adhesive layer 120 and the second adhesive layer 140 to strike the bent conductor 130 in contact with the metal layer 152. In some embodiments, the melting point of the outer coating 132 of the bent conductor 130 is lower than the melting point of the metal layer 152. Therefore, the high temperature generated by the laser can first vaporize the outer coating 132, exposing the conductive core 131 of the bent conductor 130, and then melt the metal layer 152 to solder it to the conductive core 131.

[0063] As shown in Figure 5J, this step follows the step shown in Figure 5I. In this step, the combination of the first adhesive layer 120, the bent wire 130, the second adhesive layer 140, and the flexible circuit board 150 is transferred to the protective cover plate 110 (i.e., step S240). In the embodiment shown in Figure 5J, the aforementioned combination is performed by first peeling off the release film RF1, and then attaching the first adhesive layer 120 to the protective cover plate 110. Furthermore, in this step, the release film RF3 can also be attached to the second adhesive layer 140 to protect the second adhesive layer 140.

[0064] Please refer to Figures 7A to 7H. Figures 7A to 7H are schematic diagrams illustrating intermediate steps of a manufacturing method for a touch assembly according to one embodiment of this disclosure. This embodiment is another specific implementation of the manufacturing method shown in Figure 4, and will be described in detail below.

[0065] As shown in Figure 7A, in this step, release films RF1 and RF2 are respectively attached to the opposite sides of the first adhesive layer 120.

[0066] As shown in Figure 7B, this step follows the step shown in Figure 7A. In this step, the release film RF2 is peeled off, and then the enameled wire 130A is wound onto the first adhesive layer 120. The winding method is, for example, winding along a reciprocating, meandering path onto the first adhesive layer 120. Specifically, as shown in Figure 7B, the wound enameled wire 130A is arranged on the first adhesive layer 120 in a checkerboard pattern.

[0067] As shown in Figure 7C, this step follows the step shown in Figure 7B. In this step, the second adhesive layer 140 with the release film RF3 is attached to the first adhesive layer 120. Specifically, the second adhesive layer 140 is attached to the first adhesive layer 120 with the side away from the release film RF3, to cover the first adhesive layer 120 and the enameled wire 130A. In other words, the combination of the first adhesive layer 120, the enameled wire 130A, and the second adhesive layer 140 is stacked between the release films RF1 and RF3. Compared to the formation method shown in Figure 5H where the second adhesive layer 140 is formed by curing with water-based adhesive 140A, the second adhesive layer 140 in this step is in the form of sheet adhesive.

[0068] As shown in Figure 7D, this step follows the step shown in Figure 7C. In this step, the enameled wire 130A can be cut using a cutting machine 960 to form a plurality of bent conductors 130. For example, the cutting machine 960 is a laser cutting machine. While the enameled wire 130A is laser-cut to form bent conductors 130 (i.e., loop cutting), the first adhesive layer 120, the second adhesive layer 140, and the release films RF1 and RF3 are also laser-cut simultaneously (i.e., shape cutting). Compared to cutting the enameled wire 130A with a cutting tool, this step does not cause edge adhesive pulling at the cut points of the release films RF1 and RF3. Therefore, after sequentially performing the steps shown in Figures 7B, 7C, and 7D, steps S210 and S220 can be achieved simultaneously.

[0069] In some embodiments, the laser used in the cutting machine 960 is a picosecond laser, a femtosecond laser, a CO2 laser, or a similar light source, but this disclosure is not limited thereto.

[0070] As shown in Figure 7E, this step follows the step shown in Figure 7D. In this step, the flexible circuit board 150 and the release film RF3 are aligned to expose a region of the second adhesive layer 140, so that the flexible circuit board 150 can contact the second adhesive layer 140.

[0071] As shown in Figure 7F, this step follows the step shown in Figure 7E. In this step, the flexible circuit board 150 is soldered to the bent wire 130 using a soldering machine 930. The soldering process can be referred to Figure 6 and its related descriptions, and will not be repeated here. Therefore, step S230 can be achieved by sequentially performing the steps shown in Figures 7E and 7F.

[0072] As shown in Figure 7G, this step follows the step shown in Figure 7F. In this step, a protective varnish may be sprayed onto the soldered flexible circuit board 150. The protective varnish may be, for example, three-anti-glue, but this disclosure is not limited thereto. In some embodiments, this step may also follow the step shown in Figure 5I.

[0073] As shown in Figure 7H, this step follows the step shown in Figure 7G. In this step, the combination of the first adhesive layer 120, the bent wire 130, the second adhesive layer 140, and the flexible circuit board 150 is transferred to the protective cover plate 110 (i.e., step S240). In the embodiment shown in Figure 7H, the aforementioned combination is performed by first peeling off the release film RF1, and then transferring it by attaching the first adhesive layer 120 to the protective cover plate 110. The release film RF3 remains attached to the second adhesive layer 140 to protect the second adhesive layer 140.

[0074] Please refer to Figure 8, which is a partial schematic diagram of some of the components shown in Figure 1. Specifically, Figure 8 shows the protective cover 110 and the conductive layer 13L of the touch assembly 100. As shown in Figure 8, the protective cover 110 includes a visible area 111 and a peripheral area 112. Bending conductors 130 extend from the visible area 111 to the peripheral area 112 to form signal transmission paths 133. The signal transmission path 133 includes a trace segment 133a and a bonding segment 133b. One end of the trace segment 133a is directly connected to one end of the bonding segment 133b. The trace segment 133a extends in the length direction DL. The bonding segment 133b bends repeatedly within a certain range in the width direction DW and bonds with the corresponding bonding pad 151. This increases the conductive area between the bonding segment 133b and the bonding pad 151 of the flexible circuit board 150. This not only effectively improves the process yield of laser welding the bonding segment 133b of the bent wire 130 to the bonding pad 151 (especially small and medium-sized bonding pads 151), but also effectively solves the peeling problem that easily occurs when using chip-on-film (COF) bonding technology. In addition, since the bent wire 130 in this embodiment is made of enameled wire, the bent wire 130 can overlap in the vertical direction (e.g., the Z-axis direction) when extending from the visible area 111 to the peripheral area 112, which helps to reduce the bezel width of the touch assembly 100.

[0075] Please refer to Figure 9, which is a partial schematic diagram illustrating the bonding pad 151 and signal transmission path 133 according to an embodiment of this disclosure. As shown in Figure 9, the bonding segment 133b is bent repeatedly in a sawtooth shape. In this way, the overlap area between the bonding pad 151 and the bonding segment 133b can be increased as much as possible within a given size.

[0076] Specifically, the engagement segment 133b comprises a plurality of teeth P connected in sequence. Each tooth P has two connected bevels P1 and P2 and a tooth tip formed by the two bevels P1 and P2. The bevels P1 of each tooth P are parallel to each other and close to the lower side in Figure 9, while the bevels P2 are parallel to each other and close to the upper side in Figure 9. As shown in Figure 9, in some embodiments, the tip on the left side of the engagement segment 133b can be uniformly identified as the tooth tip of the tooth P, but this disclosure is not limited thereto. In other embodiments, the tip on the right side of the engagement segment 133b in Figure 9 can also be uniformly identified as the tooth tip of the tooth P.

[0077] In some embodiments, the included angle θ1 between two adjacent teeth P is approximately 10 degrees to approximately 16 degrees. It should be noted that while a larger included angle θ1 improves pitch stability during winding, it reduces the conductive area between the engagement segment 133b and the engagement pad 151. Conversely, a smaller included angle θ1 increases the conductive area between the engagement segment 133b and the engagement pad 151, but reduces pitch stability during winding. Therefore, by ensuring that the included angle θ1 between two adjacent teeth P is within the aforementioned angle range, a better balance can be achieved between pitch stability and conductive area.

[0078] In some embodiments, the teeth P of each engagement segment 133b are inclined to the same side relative to the width direction DW. For example, in Figure 9, the teeth P are inclined upwards relative to the width direction DW. Therefore, the two inclined sides P1 and P2 of each tooth P are of unequal length, with the longest inclined side P1 having a length L1 of approximately 0.5 mm to approximately 1.1 mm. Additionally, as shown in Figure 9, the connected trace segment 133a and engagement segment 133b have another included angle θ2. The included angle θ2 is approximately 134 degrees to approximately 156 degrees. Under the aforementioned configuration, another method can help achieve a better balance between pitch stability and conductive area.

[0079] In some embodiments, each bonding pad 151 has a width W of about 0.3 mm to about 0.7 mm in the width direction DW and a length L2 of about 0.1 mm to about 6 mm in the length direction DL. The spacing S between two adjacent bonding pads 151 is about 0.3 mm to about 1.1 mm. The bonding pads 151 that meet the aforementioned size range are small in size and have a more compact arrangement, thus reducing the footprint of the bonding pads 151 on the flexible circuit board 150, thereby reducing the size of the flexible circuit board 150.

[0080] In some embodiments, the number of teeth P in each engagement segment 133b is approximately 4 to approximately 6, so that all teeth P can preferably overlap with the engagement pad 151 having the aforementioned dimensions. Specifically, while a smaller number of teeth P corresponding to the aforementioned dimensions of the engagement pad 151 may result in better pitch stability during winding, it reduces the conductive area between the engagement segment 133b and the engagement pad 151. Conversely, a larger number of teeth P corresponding to the aforementioned dimensions may increase the conductive area between the engagement segment 133b and the engagement pad 151, but it reduces pitch stability during winding. Therefore, by keeping the number of teeth P within the aforementioned range, a better balance between "pitch stability" and "conductive area" can be achieved in another way.

[0081] As shown in Figure 8, in some embodiments, the joining segments 133b of two adjacent signal transmission paths 133 are misaligned in the length direction DL. In other words, the joining segments 133b of two adjacent signal transmission paths 133 are not aligned in the width direction DW. This effectively utilizes space and avoids the overall footprint of the signal transmission paths 133 being too large.

[0082] Please refer to Figure 10, which is a schematic diagram illustrating some of the mating pads 151' according to one embodiment of this disclosure. As shown in Figure 10, the mating pads 151' are arranged in three rows, corresponding to the layout of the mating segment 133b in Figure 8. However, this disclosure is not limited thereto, and in practical applications, the mating pads 151' may also be configured with other numbers of rows (e.g., a single row) according to actual design requirements.

[0083] In some embodiments, as shown in Figure 10, each bonding pad 151' has a pointed tip 151a. Thereby, during the laser welding process, the pointed tip 151a of the bonding pad 151' can serve as an alignment mark when the image recognition device performs alignment.

[0084] Returning to Figure 6, in some embodiments, the metal layer 152 on the bonding pad 151 is solder paste with a thickness T of approximately 3 µm to approximately 11 µm. It should be noted that if the thickness T is less than 3 µm, the soldering yield between the bonding pad 151 and the bonding segment 133b may be reduced. Conversely, if the thickness T is greater than 11 µm, material spattering may occur in the metal layer 152 during laser soldering, which may also affect product yield.

[0085] From the detailed description of the specific embodiments disclosed above, it is evident that in the touch assembly of this disclosure, by using a trace design where the joint segments of each bent conductor formed in the peripheral area are repeatedly bent within a certain width direction, the conductive area between the joint segments and the bonding pads of the flexible circuit board can be increased. This not only effectively improves the process yield of laser soldering the joint segments of bent conductors to the bonding pads (especially small and medium-sized bonding pads), but also effectively solves the peeling problem that easily occurs when using die-casting technology.

[0086] Although the present disclosure has been described above with reference to embodiments, it is not intended to limit the present disclosure. Anyone skilled in the art may make various modifications and refinements without departing from the spirit and scope of the present disclosure. Therefore, the scope of protection of the present disclosure shall be determined by the appended claims.

[0087] 100, 200: Touch panel assembly 110: Protective cover plate 111: Visible Area 112: Surrounding Area 120: First adhesive layer 13L: Conductor Layer 130: Bending wire 130A: Enamelled wire 131: Conductive inner core 132: Outer cladding 133: Signal transmission path 133a: Line segment 133b: Joint section 140: Second adhesive layer 140A: Water-based adhesive 150: Flexible Circuit Board 151,151': Joint pad 151a: Pointed head 152: Metal layer 910: Winding machine 920: Glue applicator 930: Welding machine 940: Pressure Plate 950: Roller 960: Cutting machine DL: Length direction DW: Width direction EW: Pre-embedded wire G1: First group of conductors G2: Second group of conductors L1, L2: Length P: Teeth P1, P2: Hypotenuse RF1, RF2, RF3: Release film S: Spacing S110, S120, S130, S140, S210, S220, S230, S240: Steps T: Thickness W: Width θ1, θ2: included angle

Claims

1. A touch assembly comprising: a protective cover plate including a visible area and a peripheral area; a first adhesive layer disposed in the visible area of ​​the protective cover plate; a conductive layer including a plurality of bent conductive lines disposed on the first adhesive layer, the bent conductive lines including a first group of conductive lines extending along a first direction and a second group of conductive lines extending along a second direction and overlapping the first group of conductive lines, wherein each of the bent conductive lines includes a conductive inner core and an outer cover layer, the conductive layer being used for touch sensing; a second adhesive layer covering the bent conductive lines and the first adhesive layer; and a flexible circuit board including a plurality of bonding pads, wherein each of the bent conductive lines extends from the visible area to the peripheral area to form a signal transmission path, the signal transmission path including a trace segment and a bonding segment, the trace segment extending in a length direction, and the bonding segment bending repeatedly within a certain range in a width direction and bonding with a corresponding bonding pad.

2. The touch assembly as described in claim 1, wherein the engagement segment is repeatedly bent in a serrated shape.

3. The touch assembly as claimed in claim 2, wherein the engagement segment comprises a plurality of teeth connected in sequence, and an included angle between adjacent teeth is 10 to 16 degrees.

4. The touch assembly as claimed in claim 2, wherein the engagement segment comprises a plurality of teeth connected in sequence, and the number of such teeth is 4 to 6.

5. The touch assembly as claimed in claim 2, wherein the engagement segment comprises a plurality of teeth connected in sequence, the teeth being inclined to the same side relative to the width direction, each of the teeth comprising two connected bevels, the longest of the bevels of the teeth having a length of 0.5 mm to 1.1 mm.

6. The touch assembly as claimed in claim 1, wherein the junction segments of two adjacent signal transmission paths are misaligned in the length direction.

7. The touch assembly as described in claim 1, wherein the bonding pads are arranged in at least one row.

8. The touch assembly as claimed in claim 1, wherein each of the contact pads has a pointed tip.

9. The touch assembly as claimed in claim 1, wherein each of the bonding pads has a width of 0.3 mm to 0.7 mm and a length of 0.1 mm to 6 mm, and a spacing between adjacent bonding pads is 0.3 mm to 1.1 mm.

10. The touch assembly as claimed in claim 1, wherein the thickness of a metal layer on the bonding pads is 3 µm to 11 µm.

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