Three-dimensional touch device and manufacturing method thereof

Abstract

A three-dimensional touch device includes a flexible circuit board structure and an in-mold film. The flexible circuit board structure includes a flexible circuit substrate and a touch electrode. The flexible circuit substrate has an outer surface and an inner surface. The touch electrode is disposed on the outer surface. The flexible circuit substrate includes a plurality of fold lines. At least two of the fold lines are not parallel to each other. The outer contour of the flexible circuit board structure is formed by bending the flexible circuit substrate. The outer contour of the flexible circuit board structure is adapted to have a main body portion and a plurality of bent portions. The bent portions are connected to the main body portion by the fold lines. The in-mold film covers the inner surface, the outer surface, and the touch electrode. The in-mold film includes an appearance film layer covering the outer surface and the touch electrode. The outer contour of the flexible circuit board structure approaches the partial contour of the appearance film layer. A manufacturing method of a three-dimensional touch device is also provided.

Description

Technical Field

[0001] This invention relates to a touch device, and more particularly to a method for manufacturing a three-dimensional touch device with high touch sensitivity. Background Technology

[0002] Compared to traditional physical buttons, touch devices are more convenient to use, allowing users to directly slide their fingers across the screen to input various commands. Therefore, touch devices are widely used in various electronic devices, such as mobile phones, digital cameras, and tablets.

[0003] Currently common touch devices, such as touch buttons or indicator lights, achieve their touch functionality by having a touch circuit board flatly attached to the inside of the product casing. However, these products, where the touch circuit board can be flatly attached to the inside of the casing, typically have a flat structure or a simple 2D curved surface. If the product's structure is 3D curved, it's impossible to achieve touch functionality using the same method of attaching the touch circuit board flatly to the inside of the casing. Summary of the Invention

[0004] This invention provides a stereoscopic touch device and its manufacturing method. The stereoscopic touch device can achieve a 3D flexible printed circuit board (FPC) structure that approximates the appearance of complex curved surface products, thereby giving the stereoscopic touch device better touch sensitivity.

[0005] The three-dimensional touch device provided by the present invention includes: a first flexible circuit board structure and an in-mold molding film. The first flexible circuit board structure includes a first flexible circuit substrate and a first touch electrode. The first flexible circuit substrate has an outer surface and an inner surface, and the first touch electrode is disposed on the outer surface. The first flexible circuit substrate includes multiple fold lines, at least two of which are not parallel to each other. The outer contour of the first flexible circuit board structure is formed by bending the first flexible circuit substrate and is adapted to have a main body and multiple bent portions, which are connected to the main body by fold lines. The in-mold molding film covers the inner surface, the outer surface and the first touch electrode. The in-mold molding film includes an outer film layer covering the outer surface and the first touch electrode, wherein the outer contour of the first flexible circuit board structure is close to the first part of the outer film layer contour.

[0006] In one embodiment of the present invention, a through hole is formed on the first flexible circuit substrate, and the in-mold molded film further includes an inner film layer and a reinforcing pillar. The inner film layer covers the inner surface, and the reinforcing pillar is filled in the through hole and connects the outer film layer and the inner film layer.

[0007] In one embodiment of the present invention, the above-mentioned stereoscopic touch device further includes a second flexible circuit board structure, which is spliced ​​together with the first flexible circuit board structure, and the outline of the second flexible circuit board structure is close to the outline of the second part of the outer film layer.

[0008] In one embodiment of the present invention, the above-mentioned second flexible circuit board structure includes a second flexible circuit substrate and a second touch electrode. The second touch electrode is disposed on the second flexible circuit substrate and is electrically connected to at least one of the touch electrodes.

[0009] In one embodiment of the present invention, the second flexible circuit substrate is spliced ​​to the first flexible circuit substrate by means of a snap-fit ​​connection.

[0010] In one embodiment of the present invention, the main body of the first flexible circuit board structure described above has multiple edges, and the bent portions extend from the edges respectively, with each edge serving as a fold line.

[0011] In one embodiment of the present invention, the above-mentioned outer film layer has a curved surface, wherein a sub-fold line is formed on each bend, and the bend bends along the sub-fold line to adapt to approach the curved surface.

[0012] In one embodiment of the present invention, the above-mentioned three-dimensional touch device is a spherical touch button, wherein the outer film layer has a hemispherical shell structure with a peripheral side and a top, wherein the main body is flat and faces the top, the bent part is elongated, and each bent part is bent along a sub-fold line to be divided into multiple sub-regions, and the multiple sub-regions are adapted to approach the peripheral side.

[0013] In one embodiment of the present invention, the first touch electrode described above is disposed on the sub-region and the main body respectively.

[0014] In one embodiment of the present invention, the above-mentioned stereoscopic touch device further includes a second flexible circuit board structure, which is spliced ​​together with the main body, and the outline of the second flexible circuit board structure is close to the outline of the top.

[0015] In one embodiment of the present invention, the above-mentioned second flexible circuit board structure includes a second flexible circuit substrate and a second touch electrode. The second touch electrode is disposed on the second flexible circuit substrate, wherein the second flexible circuit substrate is bent into a conical shape, and the bottom edge of the conical shape is spliced ​​to the main body.

[0016] In one embodiment of the present invention, the main body portion is provided with a slot and a snap-fit ​​hole, and the second flexible circuit substrate is provided with a snap-fit ​​structure, which is suitable for snapping into the snap-fit ​​hole respectively.

[0017] The present invention provides a method for manufacturing a three-dimensional touch device, comprising: providing a first flexible circuit board structure, comprising a first flexible circuit substrate and a first touch electrode, the first flexible circuit substrate having opposing outer and inner surfaces, the first touch electrode being disposed on the outer surface, the first flexible circuit substrate comprising a plurality of fold lines, at least two of which are not parallel to each other, the outer contour of the first flexible circuit board structure being bent from the first flexible circuit substrate and adapted to have a main body and a plurality of bent portions, each bent portion being connected to the main body by a fold line; placing the first flexible circuit board structure into a first mold cavity and performing a first injection molding process to form an inner film layer covering the inner surface; and placing the first flexible circuit board structure covered with the inner film layer into a second mold cavity and performing a second injection molding process to form an outer film layer covering the outer surface and the first touch electrode, wherein the outer contour of the first flexible circuit board structure approximates a first portion of the outer contour of the outer film layer.

[0018] In one embodiment of the present invention, a through-hole is formed on the first flexible circuit substrate. During the first injection molding process, a portion of the internal film layer fills the through-hole to serve as a reinforcing pillar. In another embodiment of the present invention, the external film layer is connected to the reinforcing pillar.

[0019] In one embodiment of the present invention, the method for manufacturing the above-mentioned stereoscopic touch device further includes providing a second flexible circuit board structure, and splicing the second flexible circuit board structure and the first flexible circuit board structure together by means of snap-fit ​​connection, wherein the outer contour of the second flexible circuit board structure is close to the second part of the outer film layer contour.

[0020] In one embodiment of the present invention, the manufacturing method of the above-mentioned stereoscopic touch device further includes a welding process to weld the first flexible circuit board structure and the second flexible circuit board structure that are spliced ​​together.

[0021] In one embodiment of the present invention, the main body of the first flexible circuit board structure described above has multiple edges, and the bent portions extend from the edges respectively, with each edge serving as a fold line.

[0022] In one embodiment of the present invention, the above-mentioned outer film layer has a curved surface, wherein a sub-fold line is formed on each bend, and each bend bends along the sub-fold line to adapt to approach the curved surface.

[0023] In one embodiment of the present invention, the first injection process and the second injection process described above use the same plastic.

[0024] This invention utilizes a flexible circuit substrate bending method to achieve a 3D flexible circuit board structure with a near-curved product appearance. It selectively employs the splicing of multiple flexible circuit substrates to achieve a 3D flexible circuit board structure with a near-complex curved product appearance, allowing for greater design freedom and flexibility. Furthermore, the method for manufacturing a 3D touch device in this invention combines a 3D flexible circuit board structure with in-mold injection molding technology. Besides achieving a 3D product appearance for aesthetic and ergonomic purposes, the touch electrodes are positioned very close to the product's surface, resulting in improved touch sensitivity for the 3D touch device.

[0025] To make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments are described below in conjunction with the accompanying drawings for detailed explanation. Attached Figure Description

[0026] Figure 1 This is a cross-sectional schematic diagram of a stereoscopic touch device according to a first embodiment of the present invention.

[0027] Figure 2 This is a schematic diagram of the unfolded planar structure of the first flexible circuit board according to a first embodiment of the present invention.

[0028] Figure 3 It is along Figure 1 A cross-sectional diagram of line segment AA.

[0029] Figure 4 This is a planar schematic diagram of the first flexible circuit board structure of a stereoscopic touch device according to a second embodiment of the present invention.

[0030] Figure 5 This is a partial cross-sectional schematic diagram of a stereoscopic touch device according to a second embodiment of the present invention.

[0031] Figure 6 This is a cross-sectional schematic diagram of a stereoscopic touch device according to a third embodiment of the present invention.

[0032] Figure 7A and Figure 7B The figures shown are unfolded planar schematic diagrams of the first flexible circuit board structure and the second flexible circuit board structure according to a third embodiment of the present invention.

[0033] Figure 8 This is a schematic diagram illustrating the application of a snap-fit ​​structure and snap-fit ​​hole according to an embodiment of the present invention.

[0034] Figure 9 This is a side view of the first flexible circuit board structure and the second flexible circuit board structure after splicing according to a fourth embodiment of the present invention.

[0035] Figure 10A and Figure 10BThe figures shown are unfolded planar schematic diagrams of the first flexible circuit board structure and the second flexible circuit board structure according to the fourth embodiment of the present invention.

[0036] Figure 11 The diagram shown is a schematic of a stereoscopic touch control device applied to a steering wheel touch button according to an embodiment of the present invention.

[0037] Figures 12A to 12E The diagram shown is a flow chart of a method for manufacturing a stereoscopic touch device according to an embodiment of the present invention.

[0038] In the attached figures, the following labels are used:

[0039] 10, 10A, 10B: 3D Touchscreen Device

[0040] 12, 12A, 12B, 12C, 52, 62: First flexible circuit board structure

[0041] 14, 64: In-mold forming film

[0042] 141, 641: External film layer

[0043] 141a: Peripheral portion

[0044] 141b: Top

[0045] 142, 642: Inner membrane layer

[0046] 143, 643: Reinforcing columns

[0047] 16, 16A, 16B, 16C, 56, 66: First flexible circuit substrate

[0048] 161, 661: Outer surface

[0049] 162, 662: Inner surface

[0050] 163, 163a, 163b, 561, 661: Broken lines

[0051] 164: Through hole

[0052] 18: First touch electrode

[0053] 20, 58, 68: Main body

[0054] 22, 60, 70: Bending section

[0055] 221, 601: Sub-line

[0056] 222, 602: Subregions

[0057] 24: LED components

[0058] 26: Microcontroller

[0059] 28, 28A: Second flexible circuit board structure

[0060] 30: Grooving

[0061] 32, 32A: Fastening holes

[0062] 34, 34A: Second flexible circuit substrate

[0063] 341: Groove

[0064] 36: Second touch electrode

[0065] 38, 38A, 38B: Snap-fit ​​structure

[0066] 40: Conductive circuit

[0067] 42, 44: Parts to be connected

[0068] 46: Neck retraction

[0069] 48: Fastening hole

[0070] 481: Wide slot

[0071] 482: Narrow slot

[0072] 50: Welding point

[0073] 62a: Connecting part

[0074] 80: First mold cavity

[0075] 82: First master mold

[0076] 821: Inner side

[0077] 84: First public mold

[0078] 86: First inlet

[0079] 88: Second mold cavity

[0080] 90: Second master mold

[0081] 901: Inner side

[0082] 92: Second public mold

[0083] 921: Inner side

[0084] 94: Second glue inlet

[0085] 96: Reserved space Detailed Implementation

[0086] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the present invention.

[0087] Figure 1 This is a cross-sectional schematic diagram of a first embodiment of the stereoscopic touch device of the present invention, as shown below. Figure 1 As shown, the 3D touch device 10 includes a first flexible circuit board structure 12 and an in-mold molding film 14. The first flexible circuit board structure 12 includes a first flexible circuit substrate 16 and a first touch electrode 18. The first flexible circuit substrate 16 has an outer surface 161 and an inner surface 162. The first touch electrode 18 is disposed on the outer surface 161. In one embodiment, electronic components, such as LED elements 22, microcontrollers 26, and conductive lines (not shown), may also be disposed on the first flexible circuit substrate 16. The outer contour of the first flexible circuit board structure 12 can be formed by bending the first flexible circuit substrate 16. Figure 2 This is a schematic planar view of the first flexible circuit board structure according to a first embodiment of the present invention, in which the drawing of electronic components is omitted. Please refer to the accompanying document. Figure 1 and Figure 2 As shown, the first flexible circuit substrate 16 includes multiple fold lines 163, wherein two fold lines 163 (e.g., fold lines 163a and 163b) are not parallel to each other. The first flexible circuit substrate 16 is bent along the fold lines 163. The first flexible circuit board structure 12 is adapted to have a main body portion 20 and multiple bent portions 22, and the bent portions 22 are connected to the main body portion 20 by fold lines 163. In one embodiment, the first touch electrode 18 is disposed, for example, in the main body portion 20 and the bent portions 22.

[0088] Continuing from the above explanation, as Figure 1 As shown, the in-mold molding film 14 covers the inner surface 161, outer surface 162, and first touch electrode 18 of the first flexible circuit substrate 16. In an embodiment not shown, a portion of the first flexible circuit substrate 16 is exposed outside the in-mold molding film 14 for electrical connection with an external electronic device. The in-mold molding film 14 includes an outer surface film 141 covering the outer surface 161 and the first touch electrode 18. The outline of the first flexible circuit board structure 12 approximates a first portion of the outline of the outer surface film 141. In other words, the curved outline of the outer surface film 141 determines the curved appearance of the product using this stereoscopic touch device 10. The first flexible circuit substrate 16 is bent to approximate the curved appearance of the product, making the outer surface 161 of the first flexible circuit substrate 16 and the first touch electrode 18 thereon extremely close to the curved appearance of the product, which is more conducive to achieving touch functionality.

[0089] Figure 3 It is along Figure 1A cross-sectional view of line segment AA is shown, wherein the in-mold molded film 14 further includes an inner film layer 142 covering the inner surface 162 of the first flexible circuit substrate 16. In one embodiment, the material of the inner film layer 142 is the same as that of the outer film layer 141, but the thickness of the inner film layer 142 may be different from that of the outer film layer 141. Furthermore, the inner film layer 142 is not limited to following the curved surface of the product, and holes or grooves may be pre-drilled on the inner film layer 142 for subsequent integration with other components or devices of the product.

[0090] Figure 4 This is a schematic planar view of the first flexible circuit board structure of a second embodiment of the stereoscopic touch device of the present invention. Figure 5 This is a partial cross-sectional schematic diagram of a stereoscopic touch device according to a second embodiment of the present invention. Figure 4 As shown, the main difference between the first flexible circuit board structure 12A and the first flexible circuit board structure 12 shown in the first embodiment is that through holes 164 are formed on the first flexible circuit substrate 16A and distributed among the first touch electrodes 18. Figure 5 As shown, when the in-mold molded film 14 covers the upper surface 161 and lower surface 162 of the first flexible circuit substrate 16A, the in-mold molded film 14 has an outer film layer 141, an inner film layer 142, and reinforcing pillars 143. The reinforcing pillars 143 are filled in the through holes 164 (marked in...). Figure 4 It connects the outer film layer 141 located on the outer surface 161 and the inner film layer 142 located on the inner surface 162. The diameter of the through hole 164 is, for example, 1 millimeter (mm) or more, and the area of ​​the through hole 164 is, for example, 0.8 square millimeters (mm²) or more. By filling the through hole 164 with reinforcing pillars 143, the bonding strength between the outer film layer 141 and the inner film layer 142 is increased, thereby improving the overall structural strength of the 3D touch device 10.

[0091] Please continue reading. Figure 1 As shown, the stereoscopic touch device 10 uses a spherical touch button as an example. The outer film layer 141 is pre-designed as a hemispherical shell structure, having a curved peripheral portion 141a and a curved top portion 142b. To more closely approximate the curved surface of the outer film layer 14 and provide better touch sensitivity to the stereoscopic touch device 10, the first flexible circuit board structure 12 has sub-fold lines 221 formed on each bend 22. Each bend 22 bends along the sub-fold lines 221 to better approximate the curved surface. In one embodiment, please also refer to... Figure 2As shown, the main body 20 of the first flexible circuit board structure 12 is flat, preferably a regular polygon, such as a regular octagon; the bent portion 22 unfolds into a long strip, and the number of bent portions 22 corresponds to the number of edges of the main body 20. The bent portions 22 are connected to the edges of the main body 20 by fold lines 163, and each bent portion 22 can be divided into, for example, two sub-regions 222 via sub-fold lines 221. It can be understood that the more bent sub-regions 222 there are, the closer the surface of the outer film layer 141 is to the curve. Figure 1 As shown, in the stereoscopic touch device 10 (spherical touch button), the main body 20 faces, for example, the top 141b of the outer film layer 141, and the sub-regions 222 of each bend 22 approach the peripheral side 141a. In one embodiment, a plurality of first touch electrodes 18 are respectively disposed on each sub-region 222 and the main body 20.

[0092] Furthermore, the first flexible circuit board structure 12, which is formed by bending a single piece of first flexible circuit substrate 16, is difficult to achieve a complete appearance film layer 141 with a complex shape. Therefore, in one embodiment of the present invention, multiple flexible circuit substrates can be bent into a predetermined shape to form a flexible circuit board structure, and these multiple flexible circuit board structures can be spliced ​​together. The circuit connection between each flexible circuit board structure can be achieved by connector docking, snap-fit ​​connection, and / or direct soldering. By splicing the flexible circuit board structures, a complex 3D curved surface can be achieved, which is beneficial for the appearance film layer to be closer to the outline when it is inserted into the mold cavity for injection molding.

[0093] Figure 6 This is a cross-sectional schematic diagram of a third embodiment of the stereoscopic touch device of the present invention, as shown below. Figure 6 As shown, the stereoscopic touch device 10A still uses a spherical touch button as an example. The stereoscopic touch device 10A includes a first flexible circuit board structure 12B, a second flexible circuit board structure 28, and an in-mold molding film 14. The outer film layer 141 of the in-mold molding film 14 is preset to have a hemispherical shell structure, with a curved peripheral side portion 141a and a curved top portion 141b. For example... Figure 6 As shown, the bending profile of the bending portion 22 of the first flexible circuit board structure 12B approaches the first part of the profile of the outer film layer 141, for example, it approaches the profile of the peripheral side portion 141a of the curved surface. A second flexible circuit board structure 28 can be spliced ​​between the main body portion 20 of the first flexible circuit board structure 12B and the top 141b of the curved surface, and the outer profile of the second flexible circuit board structure 28 approaches the second part of the profile of the outer film layer 141, for example, it approaches the profile of the top 141b of the curved surface.

[0094] Following the above explanation, Figure 7A and Figure 7BThe figures shown are unfolded planar schematic diagrams of the first and second flexible circuit board structures according to a third embodiment of the present invention, wherein the electronic components are omitted. Figure 7A As shown, the main difference between the first flexible circuit board structure 12B and the first flexible circuit board structure 12 shown in the first embodiment is that the main body 20 has a slot 30 and multiple fastening holes 32, and the first touch electrodes 18 are all disposed in the sub-region 222, and not on the main body 20. Furthermore, as... Figure 7B As shown, the second flexible circuit board structure 28 includes a second flexible circuit substrate 34 and a second touch electrode 36, the second touch electrode 36 being disposed on the second flexible circuit substrate 34; the outer contour of the first flexible circuit board structure 12B is formed by bending the first flexible circuit substrate 16B, and the outer contour of the second flexible circuit board structure 28 is formed by bending the second flexible circuit substrate 34, as shown. Figure 6 As shown, the second flexible circuit board structure 28 is spliced ​​with the first flexible circuit board structure 12B, and the second touch electrode 36 is electrically connected to one of the first touch electrodes 18.

[0095] In one embodiment, such as Figure 6 , Figure 7A and Figure 7B As shown, the second flexible circuit substrate 34 is, for example, a circular plate with a groove 341, and the periphery of the circular plate has, for example, multiple snap-fit ​​structures 38. The second flexible circuit substrate 34 can be bent into a conical shape, and the multiple snap-fit ​​structures 38 are adapted to be distributed on the bottom edge of the conical shape. The second flexible circuit board structure 28 is disposed on the main body 20 of the first flexible circuit board structure 12B, and the multiple snap-fit ​​structures 38 are respectively engaged with the multiple fastening holes 32 of the main body 20, thereby splicing the second flexible circuit board structure 28 and the first flexible circuit board structure 12B together. The outline of the 3D flexible circuit board structure formed by splicing the first flexible circuit board structure 12B and the second flexible circuit board structure 28 can more closely resemble the appearance film layer 14 of a hemispherical shell structure. In one embodiment, solder joints can be provided at the splicing point to strengthen the bonding strength between the first flexible circuit board structure 12B and the second flexible circuit board structure 28 using a direct butt welding method.

[0096] In one embodiment, conductive lines 40 may also be provided on the second flexible circuit substrate 34. For example, some of the conductive lines 40 may be provided along one of the snap-fit ​​structures 38, and through the snap-fit ​​structure 38 engaging with the snap-fit ​​hole 32, the conductive lines 40 are electrically connected to the first flexible circuit board structure 12B. Furthermore, the inner film layer 142 of the in-mold molded film 14, in addition to covering the inner surface 161 of the first flexible circuit substrate 16, also fills the slot 30 of the main body 20 and covers the inner surface of the second flexible circuit substrate 34.

[0097] Figure 8 This is a schematic diagram illustrating the application of a snap-fit ​​structure and snap-fit ​​hole according to an embodiment of the present invention. The snap-fit ​​structure 38A, for example, has a necked-down portion 46 formed on the portion 42 to be connected of a flexible circuit substrate, and a snap-fit ​​hole 48 formed on the portion 44 to be connected of another flexible circuit substrate. The snap-fit ​​hole 48 is, for example, a T-shaped groove with a wide groove 481 and a narrow groove 482 that are connected. The width of the necked-down portion 46 corresponds, for example, to the width of the wide groove 481. By engaging the necked-down portion 46 with the wide groove 481, the portions 42 and 44 to be connected of the two flexible circuit substrates are overlapped and spliced ​​together. Furthermore, in one embodiment, multiple welding points 50 can be provided at the overlap to strengthen the connection strength of the two portions 42 and 44 by directly welding the welding points 50. Furthermore, the implementation of the snap-fit ​​structure 38A and the snap-fit ​​hole 48 is not limited to this. Specifically, by setting the snap-fit ​​structure 38A and the snap-fit ​​hole 48, two flexible circuit substrates bent into a preset contour can be spliced ​​and snapped together in advance to prevent them from springing back, so as to facilitate the subsequent soldering process.

[0098] Figure 9 This is a side view schematic diagram of the first flexible circuit board structure and the second flexible circuit board structure after splicing according to a fourth embodiment of the present invention. Figure 10A and Figure 10B The figures shown are unfolded planar schematic diagrams of the first and second flexible circuit board structures according to a fourth embodiment of the present invention. Figure 9 As shown, the stereoscopic touch device 10B still uses a spherical touch button as an example, but the in-mold molded film is not shown; among them, as Figure 10A As shown, the main difference between the first flexible circuit board structure 12C and the first flexible circuit board structure 12 shown in the first embodiment is that a snap-fit ​​structure 38B is provided on both sides of the end of each bend 22; also, as Figure 10B As shown, the second flexible circuit board structure 28A includes a second flexible circuit substrate 34A and a second touch electrode 36, the second touch electrode 36 being disposed on the second flexible circuit substrate 34A; the second flexible circuit board structure 28A is formed by bending the second flexible circuit substrate 34A; as shown... Figure 9 As shown, the second flexible circuit board structure 28A is spliced ​​with the first flexible circuit board structure 12C, and the second touch electrode 36 is electrically connected to one or more of the first touch electrodes 18.

[0099] Continuing from the above explanation, as Figure 10BAs shown, in the fourth embodiment, the unbent second flexible circuit substrate 34A is, for example, elongated. Multiple fastening holes 32A are formed on the second flexible circuit substrate 34A. After the first flexible circuit substrate 16C is bent into a first flexible circuit board structure 12C, the second flexible circuit substrate 34A encircles the outer ends of the multiple bent portions 22 of the first flexible circuit board structure 12C together. The snap-fit ​​structure 38B at the end of each bent portion 22 is fastened to the fastening hole 32A. This reinforces the bending effect of the bent portion 22, preventing it from turning inward or deforming due to the flow of plastic during the subsequent injection molding process.

[0100] In the above embodiments, a spherical touch button is used as an example of a stereoscopic touch device, but it is not limited to this. Figure 11 The diagram illustrates a 3D touch control device applied to a steering wheel touch button according to an embodiment of the present invention. Only the first flexible circuit board structure 52 is shown. The first flexible circuit board structure 52 is formed by bending a first flexible circuit substrate 56 and is adapted to have a main body 58 and multiple bent portions 60. The bent portions 60 are connected to the main body 58 by fold lines 561. Furthermore, a sub-fold line 601 can be formed on one of the bent portions 60 to divide the bent portion 60 into multiple sub-regions 602. This facilitates the first flexible circuit board structure 52 to approximate the contour of the outer film layer during subsequent injection molding of the outer film layer, allowing the touch button to have a 3D three-dimensional appearance, achieving both aesthetic and ergonomic effects.

[0101] Figures 12A to 12E The diagram shown is a cross-sectional flowchart illustrating a method for manufacturing a stereoscopic touch device according to an embodiment of the present invention. Figure 12A As shown, a first flexible circuit board structure 62 is provided. The first flexible circuit board structure 62 is formed by bending a first flexible circuit substrate 66 and is adapted to have a main body portion 68 and a bent portion 70. The bent portion 70 and the main body portion 68 are connected by a fold line 661. Different structural forms have been disclosed, for example, in the above embodiments and will not be repeated here. Optionally, a through hole 164 may be formed on the first flexible circuit substrate. In embodiments not shown, a 3D flexible circuit board structure composed of two or more flexible circuit board structures can also be provided for subsequent processes to meet complex appearance requirements.

[0102] Next, as Figure 12BAs shown, the first flexible circuit board structure 62 is placed into the first mold cavity 80 for the first injection molding process. In one embodiment, the first mold cavity 80 is constructed from a first female mold 82 and a first male mold 84. The first male mold 84 is provided with a first injection port 86 for plastic injection. The outer surface 661 of the first flexible circuit board structure 62 is attached to the inner surface 821 of the first female mold 82, and the connection portion 62a of the first flexible circuit board structure 62, which is pre-designed to be electrically connected to an external electronic device, is exposed outside the first mold cavity 80. Figure 12C As shown, an inner film layer 642 is formed on the inner surface 662 of the first flexible circuit board structure 62 through the first injection process; wherein, since the plastic injected through the first injection port 86 also flows into the through hole 164, a portion of the formed inner film layer 642 will fill the through hole 164 as a reinforcing pillar 643.

[0103] Next, as Figure 12D As shown, a first flexible circuit board structure 62 covered with an inner film layer 642 is placed into a second mold cavity 88 for a second injection molding process. In one embodiment, the second mold cavity 88 is constructed from a second female mold 90 and a second male mold 92, and the second male mold 92 is provided with a second injection port 94 for plastic injection. During the second injection molding process, the inner film layer 642 adheres to the inner surface 921 of the second male mold 92, and the connection portion 62a of the first flexible circuit board structure 62, which is pre-designed to be electrically connected to an external electronic device, is exposed outside the second mold cavity 88. A reserved space 96 is provided between the outer surface 661 of the first flexible circuit board structure 62 and the inner surface 901 of the second female mold 90. The outline of the reserved space 96 corresponds to the outline of the first flexible circuit board structure 62. The second injection port 94 on the second male mold 92 communicates with this reserved space 96. Ideally, the distance between the outer surface 661 of the first flexible circuit board structure 62 and the inner surface 901 of the second female mold 90 is approximately equal at each position within the reserved space 96, which facilitates the subsequent molding of the outer film layer 641 (illustrated in…). Figure 12E The thickness of the material is relatively uniform, which is beneficial for achieving touch functionality. In one embodiment, the same plastic is used in both the first and second injection processes.

[0104] Continuing from the above explanation, as Figure 12E As shown, through a second injection molding process, an outer film layer 641 is formed on the first flexible circuit board structure 62 to cover the outer surface 661 and the first touch electrode (shown in the diagram). Figure 1The outer film layer 641, the inner film layer 642, and the reinforcing pillar 643 are connected to the reinforcing pillar 643; thus, the outer film layer 641, the inner film layer 642, and the reinforcing pillar 643 constitute the in-mold molding film 64. The bending profile of the first flexible circuit board structure 62 approximates the profile (first part profile) of the outer film layer 641. Optionally, depending on complex appearance requirements, a 3D flexible circuit board structure composed of two or more flexible circuit board structures can be provided for a first injection molding process and a second injection molding process to respectively form the inner film layer and the outer film layer covering the inner and outer surfaces of the 3D flexible circuit board structure.

[0105] In one embodiment, the 3D flexible circuit board structure is formed by splicing a first flexible circuit board structure and a second flexible circuit board structure together using a snap-fit ​​connection method, and the outer contour of the second flexible circuit board structure approximates the second part of the contour of the outer film layer. Preferably, the method for manufacturing the 3D touch device further includes a soldering process to weld the spliced ​​first flexible circuit board structure and the second flexible circuit board structure together.

[0106] Based on the above, the method for manufacturing a 3D touch device according to embodiments of the present invention achieves a 3D flexible circuit board structure with a curved surface appearance by bending a flexible circuit substrate. It also selectively supplements this with the splicing of multiple flexible circuit substrates to achieve a 3D flexible circuit board structure with a complex curved surface appearance, allowing for greater design freedom and flexibility. In this embodiment, the bending portions created by multiple non-parallel fold lines in the flexible circuit board structure are difficult to attach to the inside of the product casing using traditional bonding methods. Therefore, the method for manufacturing a 3D touch device according to embodiments of the present invention combines a 3D flexible circuit board structure with in-mold injection molding technology. This not only achieves a 3D product appearance, resulting in aesthetic and ergonomic effects, but also, because the touch electrodes are very close to the product's surface, the 3D touch device has better touch sensitivity.

[0107] Although the present invention has been disclosed above by way of embodiments, it is not intended to limit the present invention. Those skilled in the art to which this invention pertains may make some modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A stereoscopic touch device, characterized in that, Include: A first flexible circuit board structure includes a first flexible circuit substrate and a plurality of first touch electrodes. The first flexible circuit substrate has an outer surface and an inner surface facing each other. The first touch electrodes are disposed on the outer surface. The first flexible circuit substrate includes a plurality of fold lines, at least two of which are not parallel to each other. The outline of the first flexible circuit board structure is formed by bending the first flexible circuit substrate and is adapted to have a main body and a plurality of bent portions. Each of the bent portions is connected to the main body by each of the fold lines. An in-mold forming film covers the inner surface, the outer surface, and the first touch electrodes. The in-mold forming film includes an outer surface film layer covering the outer surface and the first touch electrodes. The outline of the first flexible circuit board structure approximates at least a first portion of the outline of the outer surface film layer.

2. The stereoscopic touch device as described in claim 1, characterized in that, At least one through hole is formed on the first flexible circuit substrate, and the in-mold molded film further includes an inner film layer and at least one reinforcing post. The inner film layer covers the inner surface, and the at least one reinforcing post is filled in the at least one through hole and connects the outer film layer and the inner film layer.

3. The stereoscopic touch device as described in claim 1, characterized in that, It further includes a second flexible circuit board structure, which is spliced ​​together with the first flexible circuit board structure, and the outline of the second flexible circuit board structure is close to at least a second part of the outline of the outer film layer.

4. The stereoscopic touch device as described in claim 3, characterized in that, The second flexible circuit board structure includes a second flexible circuit substrate and at least one second touch electrode. The at least one second touch electrode is disposed on the second flexible circuit substrate and is electrically connected to at least one of the first touch electrodes.

5. The stereoscopic touch device as described in claim 4, characterized in that, The second flexible circuit substrate is spliced ​​to the first flexible circuit substrate by means of a snap-fit ​​connection.

6. The stereoscopic touch device as described in claim 1, characterized in that, The main body of the first flexible circuit board structure has multiple edges, and the bent portions extend from these edges respectively, with each edge serving as a fold line.

7. The stereoscopic touch device as described in claim 6, characterized in that, The outer film layer has a curved surface, wherein at least one sub-fold line is formed on each of the bending portions, and each of the bending portions bends along the at least one sub-fold line to adapt to approach the curved surface.

8. The stereoscopic touch device as described in claim 7, characterized in that, It is a spherical touch button, wherein the outer film layer has a hemispherical shell structure with a periphery and a top, wherein the main body is flat facing the top, the bending portions are elongated, and each of the bending portions bends along the at least one sub-fold line to divide into at least two sub-regions, the at least two sub-regions being adapted to approach the periphery.

9. The stereoscopic touch device as described in claim 8, characterized in that, The first touch electrodes are respectively disposed on each of the at least two sub-regions and the main body.

10. The stereoscopic touch device as described in claim 8, characterized in that, It further includes a second flexible circuit board structure, which is spliced ​​together with the main body, and the outline of the second flexible circuit board structure is similar to the outline of the top.

11. The stereoscopic touch device as described in claim 10, characterized in that, The second flexible circuit board structure includes a second flexible circuit substrate and at least one second touch electrode. The at least one second touch electrode is disposed on the second flexible circuit substrate. The second flexible circuit substrate is bent into a conical shape, and the bottom edge of the conical shape is spliced ​​to the main body.

12. The stereoscopic touch device as described in claim 11, characterized in that, The main body has a slot and multiple snap-fit ​​holes, and the second flexible circuit substrate has multiple snap-fit ​​structures that are suitable for snapping together with the snap-fit ​​holes respectively.

13. A method for manufacturing a stereoscopic touch device, characterized in that, Include: A first flexible circuit board structure is provided, comprising a first flexible circuit substrate and a plurality of first touch electrodes. The first flexible circuit substrate has an outer surface and an inner surface opposite to each other. The first touch electrodes are disposed on the outer surface. The first flexible circuit substrate includes a plurality of fold lines, at least two of which are not parallel to each other. The outline of the first flexible circuit board structure is formed by bending the first flexible circuit substrate and is adapted to have a main body and a plurality of bent portions. Each of the bent portions is connected to the main body by each of the fold lines. The first flexible circuit board structure is placed into a first mold cavity and subjected to a first injection molding process to form an internal film layer covering the inner surface; and The first flexible circuit board structure covered with the inner film layer is placed into a second mold cavity and subjected to a second injection molding process to form an outer film layer covering the outer surface and the first touch electrodes, wherein the outer contour of the first flexible circuit board structure is close to at least a first portion of the outer contour of the outer film layer.

14. The method for manufacturing a stereoscopic touch device as described in claim 13, characterized in that, At least one through hole is formed on the first flexible circuit substrate. During the first injection molding process, part of the internal film layer is filled into the at least one through hole to serve as at least one reinforcing pillar.

15. The method for manufacturing a stereoscopic touch device as described in claim 14, characterized in that, The outer membrane layer is connected to the at least one reinforcing column.

16. The method for manufacturing a stereoscopic touch device as described in claim 13, characterized in that, It further includes providing a second flexible circuit board structure, which is spliced ​​together with the first flexible circuit board structure by means of a snap-fit ​​connection, wherein the outline of the second flexible circuit board structure is close to at least a second part of the outline of the outer film layer.

17. The method for manufacturing a stereoscopic touch device as described in claim 16, characterized in that, It also includes a welding process to weld the first flexible circuit board structure and the second flexible circuit board structure together.

18. The method for manufacturing a stereoscopic touch device as described in claim 13, characterized in that, The main body of the first flexible circuit board structure has multiple edges, and the bent portions extend from these edges respectively, with each edge serving as a fold line.

19. The method for manufacturing a stereoscopic touch device as described in claim 18, characterized in that, The outer film layer has a curved surface, wherein at least one sub-fold line is formed on each of the bending portions, and each of the bending portions bends along the at least one sub-fold line to adapt to approach the curved surface.

20. The method for manufacturing a stereoscopic touch device as described in claim 13, characterized in that, The first injection molding process and the second injection molding process both use the same plastic.

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