Patent Publication Number: US-2023144835-A1

Title: Touch device

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a Continuation of U.S. patent Ser. No. 17/249,738 filed Mar. 11, 2021 and entitled “TOUCH DEVICE”, which is a Continuation of U.S. patent Ser. No. 16/162,468, filed Oct. 17, 2018 and entitled “TOUCH DEVICE” (now U.S. Pat. No. 10,976,880, issued on Apr. 13, 2021), which is a Continuation of pending U.S. patent application Ser. No. 14/830,014, filed Aug. 19, 2015 and entitled “TOUCH DEVICE” (now U.S. Pat. No. 10,133,425, issued on Nov. 20, 2018), which claims priority of Taiwan Patent Application No. 104109150, filed on Mar. 23, 2015, the entirety of which is incorporated by reference herein. 
    
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to a touch device, and in particular to an electrode design of the touch device. 
     Description of the Related Art 
     First electrodes of a bonding area of a conventional touch display panel are utilized to be electrically connected to second electrodes on a circuit substrate aligned in a specific direction. Conventionally, the first electrodes are fully corresponding to the second electrodes. A first right angle is formed on an edge of the first electrode, and a second right angle is formed on an edge of the second electrode. When the first and second electrodes are fully connected to each other, the first right angle collides with the second right angle, and the first and second right angles are fragmented due to stress concentration problems. Additionally, when the first electrodes and the second electrodes are fully connected, bubbles between the first electrodes and the second electrodes are difficult to remove. The conventional touch display panel therefore has poor adhesion, and has electrode corrosion problems. 
     BRIEF SUMMARY OF THE INVENTION 
     In one embodiment, a substrate assembly is provided, including a first substrate and a circuit substrate. The first substrate comprising an edge. An active element layer is disposed on the first substrate. A plurality of first electrodes are disposed on the first substrate and between the edge and an edge of the active element layer, and arranged along a first direction. At least one of the plurality of first electrodes is electrically connected to the active element layer, a first register mark is disposed on the first substrate. The circuit substrate is partially overlapping the first substrate in a vertical projection direction, a plurality of second electrodes is disposed on the circuit substrate, an offset distance is formed between one of the plurality of second electrodes and one of the plurality of first electrodes in the first direction, and a width of the one of the plurality of first electrodes is different from a width of the one of the plurality of second electrodes. 
     In one embodiment, a touch device is provided. The touch device includes a first substrate and a circuit substrate. The first substrate includes a touch sensing structure and a plurality of first conductive pads. At least a portion of the touch sensing structure is disposed on the first substrate. The first conductive pads are arranged along a first direction. A space area is formed between the two adjacent first conductive pads. A minimum distance between the two adjacent first conductive pads is a gap distance. A plurality of second conductive pads formed on the circuit substrate. At least one of the second conductive pads is partially overlapping a space area in a vertical projection direction of the first conductive pads. An offset distance is formed between an outline of at least one of the second conductive pads and an outline of one of the two adjacent first conductive pads in the first direction, and the offset distance is smaller than half of the gap distance. 
     A first right angle is formed on an edge of the first electrode, and a second right angle is formed on an edge of the second electrode. When the first electrode is connected to the second electrode, the first right angle is corresponding to a flat portion of the second electrode rather than the second right angle. The second right angle is corresponding to a flat portion of the first electrode rather than the first right angle. Therefore, while the first electrode is attached to the second electrode, the first right angle is prevented from colliding with the second right angle, and the stress concentration problem and fragmentation problem are avoided. Additionally, when the first electrode is connected to the second electrode, there are increased exhausting gaps formed between the first electrode and the second electrode in the first direction and the second direction. The bubbles between the first electrode and the second electrode can be exhausted smoothly through the exhausting gaps. The touch display panel of the embodiment of the invention has improved adhesion, and the electrode corrosion problem is prevented. 
     A detailed description is given in the following embodiments with reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein: 
         FIG.  1    shows a touch device of a first embodiment of the invention; 
         FIG.  2 A  is a sectional view in  2 A- 2 A′ direction of  FIG.  1   ; 
         FIG.  2 B  is a top view of the main portions of the touch device of  FIG.  1   ; 
         FIG.  3    shows a modified embodiment of the first embodiment; 
         FIG.  4    shows a touch device of a second embodiment of the invention; 
         FIG.  5 A  shows a capacitive touch device of an embodiment of the invention, wherein the first electrodes, the second electrodes and the touch sensing structure of both sides of the substrate are shown; 
         FIG.  5 B  is a top view of the embodiment of  FIG.  5 A ; 
         FIG.  6 A  shows a capacitive touch device of an embodiment of the invention, wherein the first electrodes, the second electrodes and the touch sensing structure of both sides of the substrate are shown; 
         FIG.  6 B  is a sectional view along B-B and C-C lines of  FIG.  6 A ; 
         FIG.  7    shows a capacitive touch device of an embodiment of the invention, wherein the touch sensing structure incorporated on the display is shown; and 
         FIG.  8    shows a capacitive touch device of an embodiment of the invention, wherein the touch sensing structure incorporated on the display is shown. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG.  1    shows a touch device  1  of a first embodiment of the invention, including a first substrate  10  and a circuit substrate  20 . The first substrate includes a touch sensing structure  11  (only schematically) and a plurality of first electrodes  12 . The touch sensing structure  11  is disposed on the first substrate  10 . The first electrodes  12  are electrically connected to the touch sensing structure  11 . A circuit board may include the circuit substrate  20  and a plurality of second electrodes  22 . That is to said, the plurality of second electrodes  22  are formed on the circuit substrate  20 . The circuit board can be a flexible printed circuit board. 
     The touch sensing structure  11  of the invention can be capacitive, pressure sensitive, electromagnetic, or another touch sensing structure. The capacitive touch sensing structure can utilize mutual capacitive technology or self-capacitive technology or both self-capacitive and mutual capacitive technology. For a mutual capacitive touch sensing structure, for example, the touch sensing structure  11  includes a driving electrode and a receiving electrode (not shown). The driving electrode and the receiving electrode are insulated from each other, but there is coupling capacitance therebetween. The touch sensing structure  11  is electrically connected to the first electrode  12  with a plurality of traces, wherein the traces comprise traces  112  connected to the driving electrodes and the traces  114  connected to the receiving electrodes. A ground line  116  can be disposed between the traces  112  and the traces  114  to decrease noise therebetween. A ground line  118  surrounds the traces  114  to provide static electricity protection. The first electrode  12  disposed outermost may be provided with a first electrode extending portion  122 , which can be two elongated shapes as shown in  FIG.  1   , or other shapes such as register marks when the circuit substrate  20  is attached to the first substrate  10 . 
       FIG.  2 A  is a sectional view in  2 A- 2 A′ direction of  FIG.  1   .  FIG.  2 B  is a top view of the main portions of the touch device of  FIG.  1   . With reference to  FIGS.  2 A and  2 B , a first gap G 1  is formed between two adjacent first electrodes  12 . A minimum distance between the two adjacent first electrodes  12  is a gap distance d 1  of the first gap G 1 . The gap distance d 1  is defined as the minimized straight distance between the opposite side edges of the two adjacent first electrodes  12 . The circuit substrate  20  partially overlaps the first substrate  10  in a vertical projection direction (third direction Z) of the first substrate  10 . In other words, if we look at the circuit substrate  20  and the first substrate  10  from the vertical projection direction that is perpendicular to the first substrate  10 , the circuit substrate  20  would partially overlaps the first substrate  10 . A plurality of second gaps G 2  are formed between the two adjacent second electrodes  22  (a second gap G 2  is formed between each two adjacent second electrodes  22 ). At least one of the first electrodes  12  has an offset distance d 2  with at least one of the corresponding second electrodes  22  in a first direction X. The offset distance d 2  is greater than zero and smaller than half of the corresponding gap distance d 1 . In one embodiment, the offset distance d 2  is greater than zero and smaller than one third of the corresponding gap distance d 1 . In other words, as shown in  FIG.  2 B , the two adjacent first electrodes respectively have a first electrode side edge  131  and a first electrode side edge  132  facing each other. The minimized gap distance d 1  is formed between first electrode side edges  131  and  132 . The two adjacent second electrodes  22  are electrically connected to the two corresponding first electrodes  12  by a conductive glue layer  30 . A touch sensing signal travels from the first electrodes  12  to the second electrodes  22 . One of the two second electrodes  22  has a second electrode side edge  231  located between the first electrode side edges  131  and  132 . The second electrode side edge  231  corresponds the shortest distance d 2  of the first electrode side edge  131  of the first electrode  12  in the X direction electrically connected thereto, which is smaller than half or one third of the gap distance d 1 . A gap distance d 3  is formed between a second electrode side edge  232  of another second electrode  22  and a corresponding first electrode side edge  133  in the X direction as shown in  FIG.  2 B . The value of the gap distance d 3  can be the same or close to the value of the gap distance d 2 , and the difference therebetween can be within 10% of the gap distance d 2 . 
     In one embodiment, the roughness of the first electrode side edge  131 ,  132  or  133  can be different to the roughness of the second electrode side edge  231  or  232 . Increased roughness increases attachment between the conductive glue layer  30  and the first electrode  12  or the second electrode  22 . In another embodiment, one of the first electrodes comprises a first electrode extending portion  122  as a register mark when the circuit substrate  20  is attached to the first substrate  10 . The circuit board can comprise a corresponding register mark (not shown) formed on the circuit substrate  20 . The second electrode  22  partially covers the first electrode extending portion  122 , which also improves the attachment between the conductive glue layer  30  and the first electrode  12  or the second electrode  22 , and increases the electrical connection area between the first electrode  12  and the second electrode  22 . 
     With reference to  FIG.  3   , in another embodiment, when the shape of the first electrode  12  and the shape of the second electrode  22  are symmetrical shapes (for example, rectangular, oval, etc.), each first electrode  12  comprises a first central axis  14 , and each second electrode  22  comprises a second central axis  24 . The central axis means a symmetrical central axis of the electrode. An offset distance d 2  is formed between the first central axis  14  and the corresponding second central axis  24 . 
     With reference to  FIG.  2 A , in one embodiment, a first right angle  15  is formed on an edge of the first electrode  12 , and a second right angle  25  is formed on an edge of the second electrode  22 . When the first electrode  12  is connected to the second electrode  22 , the first right angle  15  is corresponding to a flat portion of the second electrode  22  rather than the second right angle  25 . The second right angle  25  is corresponding to a flat portion of the first electrode  12  rather than the first right angle  15 . Therefore, while the first electrode  12  is attached to the second electrode  22 , the first right angle  15  is prevented from colliding with the second right angle  25 , and the stress concentration problem and fragmentation problem are avoided. 
     With reference to  FIGS.  2 A and  2 B , when the first electrode  12  is connected to the second electrode  22 , there are increased exhausting gaps formed between the first electrode  12  and the second electrode  22  in the first direction X and the second direction Y. The bubbles between the first electrode  12  and the second electrode  22  can be exhausted smoothly through the exhausting gaps. The touch display panel of the embodiment of the invention has improved adhesion, and the electrode corrosion problem is prevented. 
     With reference to  FIG.  2 A , in one embodiment, the conductive glue layer  30  contacts at least portions of the first electrode  12  and the second electrode  22  to electrically connect the first electrode  12  and the second electrode  22 . The first electrode  12  can be partially or fully electrically connected to the second electrode  22  via the conductive glue layer  30 . 
     With reference to  FIG.  2 B , in one embodiment, each first electrode  12  has a tapered portion  16 . The tapered portion  16  is not corresponding to the second electrode  22  in the vertical projection direction. The tapered portion  16  improves impedance matching and design flexibility of the trances. 
     With reference to  FIG.  3   , in one embodiment, the width of each first electrode  12  is the same as or different from the width of each second electrode  22 . The ratio between the width of each first electrode  12  and the width of each second electrode  22  is 0.8 to 1.3. The width of each first electrode  12  can be the same as the width of each second electrode  22 . 
       FIG.  4    shows a touch device  2  of a second embodiment of the invention, including a first substrate  10  and touch sensing structure  20 . The first substrate  10  comprises a touch sensing structure  11  and a plurality of first conductive pads  12 . The touch sensing structure  11  is disposed on the first substrate  10 . The first conductive pads  12  are arranged along a first direction X, wherein a space area G is formed between the two adjacent first conductive pads  12 , and a minimum distance between the two adjacent first conductive pads  12  is a gap distance d 1 . A plurality of second conductive pads  22  are formed on the circuit substrate  20 . At least one of the second conductive pads  22  partially overlaps a space area G in a vertical projection direction of the first conductive pads  12 . In other words, if we look at the second conductive pads  22  and the first substrate  10  from the vertical projection direction that is perpendicular to the second conductive pads  22 , the circuit substrate  20  would partially overlaps the space area G. An offset distance d 2  is formed between an outline of at least one of the second conductive pads  22  and an outline of one of the two adjacent first conductive pads  12  in the first direction X, and the offset distance d 2  is smaller than half of the gap distance d 1 . In other words, as viewed in the vertical projection direction, a portion of the outline of one of the two adjacent second conductive pads  22  is located in the space area G of the corresponding (electrically connected) two adjacent first conductive pads  12 . The minimum distance d 2  between the outline of the second conductive pads  22  and the outline of the corresponding (electrically connected) first conductive pads  12  in the X direction is smaller than half or one third of the gap distance d 1 . 
     In the second embodiment, when the first electrode  12  is connected to the second electrode  22 , there are increased exhausting gaps (offset) formed between the first electrode  12  and the second electrode  22  in the first direction X and the second direction Y. The bubbles between the first electrode  12  and the second electrode  22  can be exhausted smoothly through the exhausting gaps. 
     The embodiments above can be utilized in various touch devices. In the following examples, several touch devices are described, wherein the elements with the same functions follow the same labels, and the function description thereof are omitted. 
       FIGS.  5 A and  5 B  show a capacitive touch device  3  of an embodiment of the invention. A touch sensing structure  32  is disposed on two sides of a first substrate  300 , and comprises patterned driving electrodes  322  and patterned receiving electrodes  324 . A plurality of first electrodes  12  are divided into two groups respectively provided on both sides of the first substrate  300  and the two groups are respectively electrically connected to the patterned driving electrodes  322  and the patterned receiving electrodes  324 . The second electrodes  22  are formed on both sides of the circuit substrate  20 , wherein the circuit board may be a flexible printed circuit board (FPCB). A display  34  can be disposed under the capacitive touch device  3 , and a cover lens  36  can be attached to the top surface of the capacitive touch device  3 . The display  34  can be a liquid-crystal display (LCD), an organic light-emitting diode display (OLED), an electro-phoretic display (EPD), an electrode-wetting display (EWD) or a quantum dot display (QD). 
       FIGS.  6 A and  6 B  show a capacitive touch device  4  of an embodiment of the invention, wherein  FIG.  6 B  is a sectional view along lines A-A and B-B of  FIG.  6 A . The touch sensing electrode structure  44  comprises patterned driving electrodes  442  and patterned receiving electrodes  444 . The driving electrodes  442  are disposed on the first substrate  41 , and the patterned receiving electrodes  444  are disposed on the second substrate  42 . A plurality of first electrodes  12  are divided into two groups respectively disposed on the first substrate  41  and second substrate  42 , and the two groups are respectively electrically connected to the patterned driving electrodes  442  and the patterned receiving electrodes  444 . The second electrodes  22  are formed on one side of the circuit substrate  20 , and are electrically connected to the first electrodes  12 . The thickness of the first substrate  41  may be greater than or equal to the thickness of the second substrate  42 . In this embodiment, the thickness of the first substrate  41  is between 150 μm˜50 μm, the thickness of the second substrate  42  is between 110 μm˜10 μm. For example, the first substrate  41  and the second substrate  42  are plastic substrates or polymer film substrates (for example, made of polyimide). The thickness of the first substrate  41  (70 μm˜120 μm) is greater than the thickness of the second substrate  42  (10 μm˜60 μm). The thickness of the second substrate  42  is smaller, and therefore the same piece of circuit substrate  20  (such as a flexible printed circuit substrate) can be docked. A conductive glue layer (for example, anisotropy conductive film, ACF, not shown) can be disposed between the substrates  41 ,  42 , and the substrate (FPC substrate)  20  to electrically connect the first electrodes  12  to the second electrodes  22 . The substrates  41  and  42  and the circuit substrate  20  are flexible. Therefore the off difference of 10 μm˜60 μm does not decrease bonding effect. Thus, the second electrodes  22  can be simultaneously coupled to the first electrodes  12  of the substrates  41  and  42  through only one circuit substrate  20  and one bonding process. A display  464  can be disposed under the capacitive touch device  4 , and a cover lens  48  can be attached to the top surface of the capacitive touch device  4  to form a touch display device. The display  46  can be a liquid-crystal display, an organic light-emitting diode display, an electro-phoretic display, an electrode-wetting display or a quantum dot display. 
       FIG.  7    shows a capacitive touch device  5  of an embodiment of the invention. A display  50  comprises a first substrate  51  and a second substrate  52 . An active element layer  53  (e.g., a patterned stacked layer with TFT elements) is disposed on the first substrate  51 . The display  50  can be a liquid-crystal display (LCD), an organic light-emitting diode display (OLED), an electro-phoretic display (EPD), an electrode-wetting display (EWD) or a quantum dot display (QD). The touch sensing electrode structure  54  comprises patterned driving electrodes  542  and patterned receiving electrodes  544 . The driving electrodes  542  are disposed on the substrate  51 . The receiving electrodes  544  are disposed on the substrate  52 . The substrate  52  can be a color filter substrate of LCD or an upper package cover of OLED. A plurality of first electrodes  12  are divided into two groups respectively disposed on the first substrate  51  and second substrate  52 , and the two groups are respectively electrically connected to the patterned driving electrodes  542  and the patterned receiving electrodes  544 . The second electrodes  22  are formed on one side of the circuit substrate  20 , and are electrically connected to the first electrodes  12  by, for example, anisotropy conductive film (ACF). The driving electrodes  542  can be formed by any conductive layer of the active element layer  53  (for example, a metal layer with scanning lines or data lines), or formed by a separated patterned conductive layer. The driving electrodes  542  can be formed by patterned anodes or patterned cathodes of OLED element (not shown). A decorative layer  561  is provided on a cover lens  56  to shield the circuit substrate  20 , the first electrodes  12 , the second electrodes  22  and the other metal traces should be hidden (not shown). 
     A further embodiment can be derived from the embodiment of  FIG.  7   . The driving electrodes  542  can be omitted from the touch sensing structure  54 . The receiving electrodes  544  are no longer only for receiving sensing signals. According to the design of the electrode pattern, mutual capacitive sensing technology or self-capacitive sensing technology can be utilized. For example, the patterns of a part of the receiving electrodes  544  are amended to have driving function. In another example, each receiving electrodes  544  are amended to have driving and receiving functions. 
       FIG.  8    shows a capacitive touch device  6  of an embodiment of the invention. A display  60  comprises a first substrate  61  and a second substrate  62 . An active element layer  63  (e.g., a patterned stacked layer with TFT elements) is disposed on the first substrate  61 . The display  60  can be a liquid-crystal display (LCD), an organic light-emitting diode display (OLED), an electro-phoretic display (EPD), an electrode-wetting display (EWD) or a quantum dot display (QD). The touch sensing structure  64  can be a single layer or a multi-layer patterned electrode layer with the functions of receiving electrodes and driving electrodes. The substrate  62  can be a color filter substrate of LCD or an upper package cover of OLED. The cover lens  66  is attached to the second substrate  62  by optical glue layer  68 , and a light-shielding layer  661  on the cover lens  66  shields the circuit substrate  20  and the electrodes  12  and  22  therebelow. 
     The substrates (including the first and second substrates) mentioned above can be general glass substrates, alkali-free glass substrates (e.g. LCD substrate), chemically or physically treated strengthen glass substrates (e.g. cover lens), or plastic substrates such as polyethylene terephthalate (PET) substrate, polycarbonate (PC) substrate, polymethyl methacrylate (PMMA) substrate or cycloolefin polymer (COP) substrate. 
     The material of the electrodes of the touch sensing structures  11 ,  32 ,  44 ,  54  and  64  can be transparent conductive materials such as indium tin oxide (ITO) or indium zinc oxide (IZO), or metal material such as Ag, Cu, Al, Mo, Nd, Au, Cr or alloy thereof, or other materials such as graphene, silicon alkenyl, or nano silver. The first electrodes and the second electrodes  22  can utilize the material mentioned above. The touch sensing structures  11 ,  32 ,  44 ,  54  and  64  (including the first electrode traces  122  and the second electrode traces  222 ) can be single layer patterned electrodes or multi-layered patterned electrodes stacked with insulating layers. When the electrode material is metal materials, patterned metal electrodes can be constituted by thin metal traces. The width of the thin metal trace is between 0.05 μm˜6 μm, preferably between 0.08 μm˜4 μm. The aperture ratio of the patterned metal electrode in a unit area is between 85% and 99%. The first electrode  12 , the second electrode  22 , the first electrode traces  122  and second electrode traces  222  can be formed by patterned metal electrodes. 
     In the embodiments, the first electrode  12  is the first conductive pads  12 , and the second electrode  22  is the second conductive pads  22 , which are the same elements with same functions and different names. 
     The cover lenses  36 ,  48 ,  56  and  66  in the embodiments described above can be physically or chemically treated tempered glass substrates, e.g., chemically ion exchange treated glass substrate or physical heat treated glass substrate. The cover lenses  36 ,  48 ,  56  and  66  can also be a polarizing sheet (linear or circular polarizing sheet) to replace the cover lenses  6 ,  48 ,  56  and  66 . Multi-functional film (single layer or multi-layer) is coated or plated on the surface of the polarizing sheet to provide a function such as anti-reflective, anti-glare, anti-pollution, or improving light transmittance. 
     Use of ordinal terms such as “first”, “second”, “third”, etc., in the claims to modify a claim element does not by itself connote any priority, precedence, or order of one claim element over another or the temporal order in which acts of a method are performed, but are used merely as labels to distinguish one claim element having a certain name from another element having the same name (but for use of the ordinal term). 
     While the invention has been described by way of example and in terms of the preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. On the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.