Patent Publication Number: US-11656727-B2

Title: Touch electrode structure and manufacture method thereof, touch panel, and electronic device

Description:
TECHNICAL FIELD 
     Embodiments of the present disclosure relate to a touch electrode structure and a manufacture method thereof, a touch panel, and an electronic device. 
     BACKGROUND 
     A user interface with touch functions is widely used in various electronic devices, and a touch electrode structure has a great influence on the touch sensitivity. 
     SUMMARY 
     At least one embodiment of the present disclosure provides a touch electrode structure, comprising a first touch electrode and a second touch electrode, wherein the first touch electrode extends along a first direction, the second touch electrode extends along a second direction, the first direction intersects with the second direction, and a size of the first touch electrode in the first direction is greater than a size of the second touch electrode in the second direction; the first touch electrode and the second touch electrode are insulated from and intersect with each other to form a mutual capacitance for touch detection; the first touch electrode comprises a first hollow region, the second touch electrode comprises a second hollow region, and a hollow area of the first touch electrode is greater than a hollow area of the second touch electrode; and the touch electrode structure further comprises at least one first dummy electrode, the at least one first dummy electrode is within the first hollow region and is arranged in a same layer as at least part of the first touch electrode, and the at least one first dummy electrode and the at least part of the first touch electrode are insulated from each other. 
     In some embodiments, the first hollow region comprises a plurality of first sub-hollow regions spaced apart from each other, and the touch electrode structure further comprises a plurality of first dummy electrodes which are respectively within the plurality of first sub-hollow regions. 
     In some embodiments, the touch electrode structure according to claim  1 , wherein an area of the second hollow region is 0. 
     In some embodiments, the second hollow region comprises a plurality of second sub-hollow regions spaced apart from each other, and the touch electrode structure further comprises a plurality of second dummy electrodes which are respectively within the plurality of second sub-hollow regions. 
     In some embodiments, areas of the plurality of first sub-hollow regions are identical, and areas of the plurality of second sub-hollow regions are identical. 
     In some embodiments, an amount of the plurality of first sub-hollow regions is identical to an amount of the plurality of second sub-hollow regions, and an area of each first sub-hollow region is greater than an area of each second sub-hollow region. 
     In some embodiments, an amount of the plurality of first sub-hollow regions is greater than an amount of the plurality of second sub-hollow regions, and an area of each first sub-hollow region is identical to an area of each second sub-hollow region. 
     In some embodiments, the first touch electrode comprises a plurality of first touch electrode portions connected in sequence in the first direction, and the second touch electrode comprises a plurality of second touch electrode portions connected in sequence in the second direction; and the plurality of first sub-hollow regions are within the plurality of first touch electrode portions, and the plurality of first dummy electrodes and the plurality of first touch electrode portions are arranged in a same layer and insulated from each other. 
     In some embodiments, the first touch electrode and the second touch electrode form a plurality of touch units at intersections, and each touch unit comprises at least one part of each of two first touch electrode portions connected at the intersections and a part of each of two second touch electrode portions connected at the intersections; and for each touch unit, a total hollow area of the two first touch electrode portions is greater than a total hollow area of the two second touch electrode portions. 
     In some embodiments, for each first touch electrode portion, a ratio of the hollow area to an electrode area of the first touch electrode portion ranges from 0.1 to 1. 
     In some embodiments, each first dummy electrode comprises a plurality of first interdigital structures, and each first interdigital structure and the first touch electrode portion where the first interdigital structure is embedded in are in a same plane. 
     In some embodiments, each first dummy electrode comprises a first body portion connected to the plurality of first interdigital structures, and the first body portion comprises a plurality of edges, and each edge corresponds to at least two first interdigital structures. 
     In some embodiments, at least one first touch electrode portion where the first dummy electrode is located comprises a plurality of second interdigital structures, and the at least one first touch electrode portion is interdigitated with second touch electrode portions adjacent to the at least one first touch electrode portion in the same plane through the plurality of second interdigital structures to form the mutual capacitance. 
     In some embodiments, an extending direction of at least one first interdigital structure of the first dummy electrode and an extending direction of at least one second interdigital structure of the first touch electrode portion where the first dummy electrode is located are parallel to each other. 
     In some embodiments, on each edge of the first body portion of the first dummy electrode, one of two adjacent first interdigital structures points to one of the plurality of second interdigital structures, and the other of the two adjacent first interdigital structures points to a gap between the two adjacent second interdigital structures. 
     In some embodiments, the first touch electrode portion further comprises a second body portion connected to the plurality of second interdigital structures, and the second body portion comprises a plurality of edges, and an amount of second interdigital structures corresponding to each edge ranges from 3 to 10. 
     In some embodiments, an average width of each second interdigital structure ranges from 1/10 to ¼ of a center distance between adjacent first touch electrode portions. 
     In some embodiments, an average length of each second interdigital structure ranges from 1/10 to ⅓ of a center distance between adjacent first touch electrode portions. 
     In some embodiments, a shape of the first interdigital structure is at least one selected from: rectangle, triangle and trapezoid. 
     In some embodiments, adjacent first touch electrode portions are electrically connected through a first connection portion to form the first touch electrode, and adjacent second touch electrode portions are electrically connected through a second connection portion to form the second touch electrode; and the first touch electrode portion, the second touch electrode portion and the first connection portion are arranged in a same layer and made of a same material, and are separated from the second connection portion by an insulating layer, and adjacent first touch electrode portions are electrically connected by the second connection portion through a via in the insulating layer. 
     In some embodiments, the first touch electrode portion and the second touch electrode portion are both made of transparent conductive materials, or both comprise a metal grid structure. 
     At least one embodiment of the present disclosure provides a touch panel, comprising the touch electrode structure as described above. 
     At least one embodiment of the present disclosure provides an electronic device, comprising the touch electrode structure or the touch panel as described above. 
     In some embodiments, further comprising a display panel, wherein the display panel comprises a substrate, a light-emitting element on the substrate, and an encapsulation layer on a side of the light-emitting element away from the substrate; and the touch electrode structure is on a side of the encapsulation layer away from the substrate. 
     At least one embodiment of the present disclosure provides a manufacture method for manufacturing a touch electrode structure, comprising forming a first touch electrode and a second touch electrode, wherein the first touch electrode extends along a first direction, the second touch electrode extends along a second direction, and the first direction intersects with the second direction; a size of the first touch electrode in the first direction is greater than a size of the second touch electrode in the second direction; the first touch electrode and the second touch electrode intersect with each other to form a mutual capacitance for touch detection; the first touch electrode comprises a first hollow region, the second touch electrode comprises a second hollow region, and a hollow area of the first touch electrode is greater than a hollow area of the second touch electrode; and the touch electrode structure further comprises at least one first dummy electrode, the at least one first dummy electrode is within the first hollow region and is arranged in a same layer as at least part of the first touch electrode, and the at least one first dummy electrode and the at least part of the first touch electrode are insulated from each other. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In order to clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings of the embodiments will be briefly described hereinafter. It is obvious that the described drawings are only related to some embodiments of the present disclosure and are not limitative to the present disclosure. 
         FIG.  1    is a schematic diagram of a touch electrode structure provided by embodiments of the present disclosure; 
         FIGS.  2 A- 2 C  are schematic diagrams of dummy electrodes provided by embodiments of the present disclosure; 
         FIG.  3 A  is a schematic diagram of a touch electrode structure provided by other embodiments of the present disclosure; 
         FIG.  3 B  is a sectional view of  FIG.  3 A  taken along a section line A-A′; 
         FIGS.  4 A- 4 D  are schematic diagrams of touch electrode structures and electric field distribution of the touch electrode structures provided by some embodiments of the present disclosure; 
         FIG.  5    is a schematic diagram of a first touch electrode provided by some embodiments of the present disclosure; 
         FIGS.  6 A- 6 B  are schematic diagrams of touch electrode structures provided by still other embodiments of the present disclosure; 
         FIG.  7    is a schematic diagram of a touch panel provided by some embodiments of the present disclosure; 
         FIG.  8 A  is a schematic diagram of an electronic device provided by some embodiments of the present disclosure; and 
         FIG.  8 B  is a schematic diagram of an electronic device provided by other embodiments of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     In connection with the attached drawings, the technical solutions of the embodiments will be clearly and completely described with reference to the non-limiting example embodiments shown in the drawings and detailed in the following description, and the example embodiments of this present disclosure and their various features and advantageous details are more fully explain. It should be noted that the features shown in the figures are not necessarily drawn to scale. This present disclosure omits descriptions of known materials, components, and process techniques so as not to obscure example embodiments of the present disclosure. The examples given are only intended to facilitate understanding of the implementation of the exemplary embodiments of the present disclosure and further enable those skilled in the art to implement the exemplary embodiments. Therefore, these examples should not be understood as limiting the scope of the embodiments of the present disclosure. 
     Unless otherwise defined, the technical terms and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art to which the present disclosure belongs. The terms “first,” “second,” etc., which are used in the present disclosure, are not intended to indicate any sequence, amount or importance, but distinguish various components. Furthermore, in various embodiments of the present disclosure, the same or similar reference numerals refer to the same or similar components. 
     A mutual capacitance type of touch electrode structure includes a touch driving electrode and a touch sensing electrode, the touch driving electrode and the touch sensing electrode form a mutual capacitance for touch detection, the touch driving electrode is used for inputting excitation signals (touch driving signals), and the touch sensing electrode is used for outputting touch sensing signals. By inputting an excitation signal to, for example, a longitudinally extending touch driving electrode and receiving a touch sensing signal from, for example, a transversely extending touch sensing electrode, a capacitance value of a coupling point (for example, an intersection point) of a transverse electrode and a longitudinal electrode can be obtained. In the case where a finger touches the capacitive screen, it affects the coupling between the touch driving electrode and the touch sensing electrode, thus changing the capacitance between the two electrodes. According to the two-dimensional capacitance variation data of a touch screen, coordinates of respective touch points (intersection points) can be calculated. 
     The load (such as resistance-capacitance load) on the touch electrode will directly affect the transmission speed of a signal and the accuracy of a touch signal, thus affecting the touch sensitivity of the touch electrode structure. The inventors found that a touch region is usually rectangular, and one of the touch driving electrode and the touch sensing electrode extends along a length direction of the rectangle, while the other extends along a width direction of the rectangle. The touch electrode extending along the length direction is longer, so the load is larger. In order to improve the touch sensitivity of the touch electrode structure, it is necessary to reduce the load on the touch electrode. 
     Embodiments of the present disclosure provide a touch electrode structure, a first touch electrode includes a first hollow region, and a second touch electrode includes a second hollow region. The touch electrode structure also includes at least one first dummy electrode, which is located within the first hollow region and is arranged on the same layer as at least part of the first touch electrode and insulated from each other. 
     Self-capacitance (parasitic capacitance) on the first touch electrode can be effectively and pertinently reduced by setting a hollow region on the long first touch electrode and setting the hollow region on the first touch electrode greater than a hollow region on the second touch electrode, thereby improving the touch sensitivity of the touch electrode structure. In addition, by arranging the dummy electrode in a same layer as the touch electrode in the hollow region, the uniformity of a film layer can be improved, thereby improving the product yield. 
       FIG.  1    is a touch electrode structure  10  provided by embodiments of the present disclosure. As shown in  FIG.  1   , the touch electrode structure includes a plurality of first touch electrodes  110  (T 1 -Tn) extending along a first direction D 1  and a plurality of second touch electrodes  120  (R 1 -Rn) extending along a second direction D 2 , and the first direction D 1  intersects with the second direction D 2 , for example, the first direction D 1  is perpendicular to the second direction D 2 . A size (length) of the first touch electrode  110  in the first direction D 1  is greater than a size (length) of the second touch electrode  120  in the second direction, so a load of the first touch electrode  110  is greater than a load of the second touch electrode. For example, a length of the first touch electrode  110  is about twice a length of the second touch electrode  120 . The term “about” here means approximately and not exactly, and measurement errors within allowable ranged is permitted. For example, about twice the length may indicate 1.98 or 2.1 times of the length. 
     For example, the first touch electrode  110  is the touch driving electrode, and the second touch electrode  120  is the touch sensing electrode. However, the embodiments of the present disclosure are not limited to this case. In other examples, the first touch electrode  110  may be the touch sensing electrode and the second touch electrode  120  may be the touch driving electrode. 
     Each first touch electrode  110  includes first touch electrode portions  111  arranged in sequence along the first direction D 1  and connected to each other, and each second touch electrode  120  includes second touch electrode portions  121  arranged in sequence along the second direction D 2  and connected to each other. As shown in  FIG.  1   , each first touch electrode portion  111  and each second touch electrode portion  121  is rhombic. In other examples, the first touch electrode portion  111  and the second touch electrode portion  121  can also have other shapes, such as, triangles, strips, and the like. 
     The touch electrode structure  10  further includes a first connection part and a second connection part (not shown), first touch electrode portions  111  which are adjacent in the first direction D 1  are electrically connected through the first connection part, so as to form the first touch electrode  110 , and second touch electrode portions  121  which are adjacent in the second direction D 2  are electrically connected through the second connection part, so as to form the second touch electrode  120 . Details can be referred to the description of  FIG.  3 A  and  FIG.  3 B  provided hereinafter. 
     Each first touch electrode  110  and each second touch electrode  120  are insulated from and intersect with each other to form a plurality of touch units  20  at intersections, and each touch unit includes a part of each of two first touch electrode portions connected at the intersections and at least one part of each of two second touch electrode portions connected at the intersections.  FIG.  1    shows an enlarged schematic diagram of a touch unit  20  on a right side. As shown in the figure, each touch unit  20  includes half regions of two first touch electrode portions  111  adjacent to each other and half regions of two second touch electrode portions  121  adjacent to each other, that is, a region including one first touch electrode portion  111  and one second touch electrode portion  121  on average, and the intersection of the first touch electrode portion  111  and the second touch electrode portion  121  in each touch unit  20  (that is, the intersection of the first connection part and the second connection part) forms a reference point for calculating coordinates. In the case where a finger touches a capacitive screen, it affects the coupling between the first touch electrode and the second touch electrode near a touch point, thus changing the mutual capacitance between the two electrodes. According to the capacitance variation data of the touch screen, the coordinates of each touch point can be calculated based on the reference point. For example, an area of each touch unit  20  is equal to an area where a user&#39;s finger contacts the touch panel. If the area of the touch unit is too large, it may cause a touch blind spot on the panel, and if the area of the touch unit is too small, it may cause a false touch signal. 
     An average edge length of each touch unit  20  is P, which is called a pitch of the touch electrode structure. For example, the pitch P ranges from about 3.7 mm to about 5 mm, for example, about 4 mm; this is because a diameter of the user&#39;s finger in contact with the touch panel is about 4 mm. The term “about” here means approximately and not exactly, and measurement errors within allowable ranged is permitted. For example, about 3.7 mm may include 3.67 mm, and about 5 mm may include 5.02 mm. For example, the pitch is the same as an average edge length of each first touch electrode portion  111  and an average edge length of each second touch electrode portion  121 , and also is the same as a center distance between adjacent first touch electrode portions  111  and a center distance between adjacent second touch electrode portions  121 . 
     As shown in  FIG.  1   , the first touch electrode  110  includes a first hollow region  210 , and the second touch electrode  120  includes a second hollow region  220 . By setting the hollow area, an electrode area (effective area) and parasitic capacitance (self-capacitance) of the touch electrode are reduced, thus reducing the load on the touch electrode. 
     A hollow area of the first touch electrode  110  (that is, a total area of the first hollow region  210 ) is greater than a hollow area of the second touch electrode  120  (that is, a total area of the second hollow region  220 ), because the load on the first touch electrode is greater than the load on the second touch electrode, which directly affects the accuracy of touch signal sensing. 
     In some examples, only the first touch electrode  110  may be provided with a hollow region, and it is not necessary to provide a hollow region on the second touch electrode  120 , that is, the area of the hollow region  220  on the second touch electrode  120  is 0, which can simplify the process. 
     In some examples, for each touch unit  20 , the hollow area of the first touch electrode portion  111  (total hollow area of the two first touch electrode portions  111 ) in the touch unit  20  is greater than that of the second touch electrode portion  121  (total hollow area of the two second touch electrode portions  121 ). 
     For example, hollow areas of respective first touch electrode portions  111  are the same as each other. Hollow areas of respective second touch electrode portions  121  are the same as each other. The hollow area of each first touch electrode portion  111  is greater than the hollow area of the second touch electrode portion  121 . 
     In other examples, for each first touch electrode  110 , hollow regions with different densities may also be arranged in different regions. For example, in the case where the touch electrode structure  10  is applied to a curved touch panel or a flexible touch panel, the region of the first touch electrode  110  corresponding to a bending region can be provided with a higher density of hollow regions than a planar region. Here, the term “density” may indicate how many hollow areas there are per unit area. For example, if a gap between adjacent hollow areas is smaller, then the density of hollow regions is higher, provided that the hollow areas are identical. This is because the bending lengthens the power lines between the touch electrodes forming the mutual capacitance, so that an equivalent distance between the touch electrodes is lengthened, so the capacitance value of the mutual capacitance becomes smaller, which reduces the touch sensitivity of the bending region. By setting a higher density hollow area in the bending region, the touch sensitivity of the touch panel in the bending region can be improved. For example, the hollow area of the first touch electrode portion  111  located within the bending region is greater than the hollow area of the first touch electrode portion  111  located within the plane region. 
     Corresponding to the hollow region, the touch electrode structure  10  further includes at least one first dummy electrode  211 . The at least one first dummy electrode  211  is located within the first hollow region  210  of the first touch electrode  110 , and is arranged in the same layer as at least part of the first touch electrode  110 , and the at least one first dummy electrode  211  and the at least part of the first touch electrode  110  are insulated from each other. For example, the first dummy electrode  211  and a part of the first touch electrode  110  adjacent to the first dummy electrode  211  are arranged in the same layer. For example, each first dummy electrode  211  is insulated from the first touch electrode portion  111  and is in the same layer as the first touch electrode portion  111 . 
     For example, the touch electrode structure  10  may further include at least one second dummy electrode  221 , the at least one second dummy electrode  221  is located within the second hollow region  220  of the second touch electrode  120 , and is arranged in the same layer as at least part of the second touch electrode  120 , and the at least one second dummy electrode  221  and the at least part of the second touch electrode  120  insulated from each other. For example, the second dummy electrode  221  and a part of the second touch electrode  120  adjacent to the second dummy electrode  221  are arranged in the same layer. For example, each second dummy electrode  221  is insulated from and in the same layer as the second touch electrode portion  121 . 
     It should be noted that “arranged in the same layer” in this present disclosure means that two or more structures are formed by the same film layer through the same or different patterning processes, so the materials are the same. 
     For example, the first dummy electrode  211  and the second dummy electrode  221  are in a floating state, for example, they are not electrically connected to other structures or do not receive any electrical signals. 
     For example, as shown in  FIG.  1   , the first hollow region  210  may include a plurality of first sub-hollow regions  212  spaced apart from each other; the plurality of first dummy electrodes  211  are respectively arranged in the plurality of first sub-hollow regions  212  in a one-to-one correspondence. The second hollow region  220  may include a plurality of second sub-hollow regions  222  spaced apart from each other. The plurality of second dummy electrodes  221  are respectively arranged in the plurality of second sub-hollow regions  222  in a one-to-one correspondence. The hollow regions are scattered in multiple regions, so as to avoid the touch blind spot caused by the oversized area of a single hollow region. For example, the arrangements of the first sub-hollow regions  212  in respective first touch electrode portions  111  are the same. For example, the arrangements of the second sub-hollow regions  222  in respective second touch electrode portions  121  are the same. 
     For example, the areas of the first sub-hollow regions  212  are the same, and the areas of the second sub-hollow regions  222  are the same. 
     For example, an amount of the first sub-hollow regions  212  is the same as an amount of the second sub-hollow regions  222 , and the area of each first sub-hollow region  212  is greater than the area of each second sub-hollow region  222 . 
     For example, the amount of the first sub-hollow regions  212  is greater than the amount of the second sub-hollow regions  222 , and the area of each first sub-hollow region  212  is the same as the area of each second sub-hollow region  222 . For example, a total amount of the first sub-hollow regions  212  is 1.5 times, 2 times or 3 times of a total amount of the second sub-hollow regions  222 . For example, for each touch unit  20 , the amount of the first sub-hollow regions  212  is 1.5 times, 2 times or 3 times the amount of the second sub-hollow regions  222 . 
     For example, as shown in  FIG.  1   , the plurality of first sub-hollow regions  212  are distributed within the first touch electrode portion  111 . For example, for each first touch electrode portion  111 , a ratio of the hollow area to the electrode area (effective area) of the first touch electrode portion ranges from 0.1 to 1. If the hollow area is too small, it will not improve the touch sensitivity, while if the hollow area is too large, it will cause touch blind spots and reduce the touch sensitivity. For example, for each first touch electrode portion  111 , the hollow area is the same as the electrode area of the first touch electrode portion  111 . For example, for each first touch electrode portion  111 , the hollow area is slightly less than the electrode area of the first touch electrode portion  111 , for example, the ratio of the hollow area to the electrode area of the first touch electrode portion  111  is 45:55. 
     For example, each dummy electrode has the same outline as the hollow region where the dummy electrode is located, that is, the dummy electrode is embedded in the touch electrode where the dummy electrode is located; a boundary region exists between the dummy electrode and the touch electrode, and the dummy electrode and the touch electrode are insulated from each other by the boundary region. An average size of the boundary region (a average distance between the dummy electrode and the touch electrode) is a minimum size that satisfies the design rule, for example, 3 microns to 6 microns. In this way, the uniformity of the electrode film can be improved and the process yield can be improved. For example, a first boundary region (gap) between each first dummy electrode  211  and the first touch electrode  110  in which the first dummy electrode  211  is embedded has the same size, and a second boundary region between each second dummy electrode  221  and the second touch electrode  120  in which the second dummy electrode  211  is embedded has the same size. For example, the first boundary region and the second boundary region have the same size. 
     For example, the boundary region extends along a curve, that is, the outline of the dummy electrode has a curved structure. For example, the outline includes a sawtooth structure. Such a design enables the region involved by dummy electrodes larger under the same area. Due to the dummy electrodes embedded in the touch electrodes, the region affected by touch electrodes is relatively larger, which can avoid touch blind spots caused by excessive concentration of dummy electrodes. In addition, because the dummy electrode are embedded in the touch electrode, that is, an inner outline of the touch electrode is also a curved structure, this structure can increase a perimeter of the inner outline compared with a straight linear structure, thereby increasing the mutual capacity of the touch electrode. 
       FIGS.  2 A- 2 C  schematically show different examples of enlarged schematic diagrams of dummy electrodes, respectively. Hereinafter, the first dummy electrode  211  will be taken as an example to illustrate the dummy electrode in the present disclosure, and this case is also applicable to the second dummy electrode  221 . As shown in  FIG.  2 A , each first dummy electrode  211  includes a first body portion  213  and a plurality of first interdigital structures  214  connected to the first body portion  213 , and the plurality of first interdigital structures are uniformly arranged around the first body portion  213 . For example, each first interdigital structure  214  may further include a sawtooth structure. As shown in  FIG.  2 B , for example, the first body portion  213  includes a plurality of edges, such as a rectangle, and an amount of first interdigital structures corresponding to each edge is at least 2. For example, the shape of the first interdigital structure  214  includes at least one of rectangle, triangle, and trapezoid. 
     In another example, as shown in  FIG.  2 C , each first dummy electrode  221  includes a plurality of sawtooth strips  216  connected by connection portions  215 , for example, each sawtooth strip is W-shaped. 
     For example, the mutual capacity between the first touch electrode  110  and the second touch electrode  120  can be improved by providing an interdigital structure in the touch electrode portion, thereby improving touch sensitivity. In each touch unit  20 , the first touch electrode  110  and the second touch electrode  120  are coupled at the intersection to form the mutual capacitance, and the first touch electrode  110  and the second touch electrode  120  are also coupled at adjacent (opposite) positions to form the mutual capacitance, which contributes to the touch sensing of the touch unit  20 . Increasing the coupling region between the first touch electrode  110  and the second touch electrode  120 , that is, increasing the edge length of the first touch electrode  110  and the second touch electrode  120  opposite to each other, can effectively improve the mutual capacitance between the first touch electrode  110  and the second touch electrode  120 , thus improving the touch sensitivity. 
       FIG.  3 A  shows a schematic diagram of a touch electrode structure provided by other embodiments of the present disclosure. As shown in  FIG.  3 A , at least one first touch electrode portion  111  includes a plurality of second interdigital structures  112 , and a first touch electrode portion  111  is interdigitated with second touch electrode portions  121  adjacent to the first touch electrode portion  111  in the same plane to form the mutual capacitance. That is, the second touch electrode portion  121  interdigitated with the first touch electrode portion  111  also has an interdigital structure (third interdigital structure)  122 . The interdigital structure can increase the perimeter of the touch electrode part in case of the same area, so the mutual capacitance can be effectively improved without increasing the self-capacitance (parasitic capacitance) of the touch electrode part, thereby improving the touch sensitivity. 
     For example, first touch electrode portions  111  adjacent in the first direction D 1  are connected by the first connection portions (not shown in  FIG.  3 A ) to form the first touch electrodes  110  extending in the first direction D 1 , and second touch electrode portions  121  adjacent in the second direction D 2  are connected by the second connection portions  125  to form the second touch electrodes  120  extending in the second direction D 2 . As shown in  FIG.  3 A , each first touch electrode portion  111  further includes an electrode connection portion  114  for connecting with the first connection portion. 
     For example, the first touch electrode portion  111  and the second touch electrode portion  121  are arranged in the same layer, is arranged in the same layer as one of the first connection part and the second connection part  125 , and are separated from the other by an insulating layer and is electrically connected to the other through a via in the insulating layer. 
       FIG.  3 B  shows an example of the sectional view of  FIG.  3 A  taken along a sectional line A-A′. As shown in  FIG.  3 B , the touch electrode structure  10  is disposed on a base substrate  101 , for example, the base substrate  101  may be a rigid substrate (e.g., a glass substrate) or a flexible substrate (e.g., an organic flexible substrate). The first touch electrode portion  111 , the second touch electrode portion  121  and the second connection portion  125  are arranged in the same layer and made of the same material, and are separated from the first connection portion  115  by the insulating layer  102 . For example, the first connection portion  115  is closer to the base substrate  101  than the second connection portion  125 . The first connection portion  115  is electrically connected to the first touch electrode portion  111  through the via  103  in the insulating layer  102 , thereby electrically connecting the first touch electrode portions  111  adjacent in the first direction D 1  to form the first touch electrode  110 . The second connection portion  125  and the first connection portion  115  overlap each other in a direction perpendicular to the base substrate  101  to form the mutual capacitance for touch detection. 
     In a certain range, the greater the length of the interdigital structures, the higher the distribution density of the interdigital structures will be and the greater the amount of the interdigital structures will be, and the more the edge length increases and the greater the improvement of mutual capacity will be made.  FIGS.  4 A- 4 D  schematically illustrate several touch electrode structures and electric field distribution of the touch electrode structures,  FIG.  4 A  schematically illustrates a touch electrode structure without an interdigital structure, and  FIGS.  4 B- 4 D  schematically illustrate several touch electrode structures provided by embodiments of the present disclosure. For the sake of clarity, only the structure of one edge of the first touch electrode portion  111  and one edge of the second touch electrode portion  121  corresponding the edge of the first touch electrode portion  111  and the electric field coupling between them are shown in the figure. It should be noted that the electrode area of the first touch electrode portion  111  and the electrode area of the second touch electrode portion  121  shown in  FIGS.  4 A- 4 D  are the same, that is, the self-capacitances of the touch electrode parts are basically the same. 
     As shown in  FIG.  4 A , in the case where the edges of the touch electrode parts are not provided with interdigital structures, directions of electric field lines are parallel to each other, and the directions all point from one touch electrode part to another, for example, from the first touch electrode portion  111  to the second touch electrode portion  121 . 
     As shown in  FIG.  4 B , each first touch electrode portion  111  has ten (10) second interdigital structures  112  on an edge, and each second touch electrode portion  121  has eleven (11) third interdigital structures  122  on an edge. Each second interdigital structure  112  and each third interdigital structure  122  are strip-shaped. A length L 1  of each second interdigital structure  112  is about 600 microns. A length of each third interdigital structure  122  is also about 600 microns. A width L 2  of each second interdigital structure  112  is about 400 microns. A width of each third interdigital structure  122  is also about 400 microns. A spacing d between adjacent second interdigital structures  112  is about 250 microns. A spacing d between adjacent third interdigital structures  122  is about 250 microns. The term “about” here means approximately and not exactly, and measurement errors within allowable ranged is permitted. 
     As shown in  FIG.  4 C , each first touch electrode portion  111  has ten (10) eleven (11) second interdigital structures  112  on an edge, and each second touch electrode portion  121  has ten (10) third interdigital structures  122  on an edge. The length L of each second interdigital structure  112  and each third interdigital structure  122  is 500 microns and the width of each second interdigital structure  112  and each third interdigital structure  122  is 400 microns. A spacing d between adjacent second interdigital structures  112  is 250 microns. Compared with the structure shown in  FIG.  4 B , the length of each interdigital structure is reduced in  FIG.  4 C . 
     As shown in  FIG.  4 D , each first touch electrode portion  111  has five (5) second interdigital structures  112  on an edge, and each second touch electrode portion  121  has six (6) third interdigital structures  122  on an edge. The length L of each second interdigital structure  112  and each third interdigital structure  122  is 500 microns and the width of each second interdigital structure  112  and each third interdigital structure  122  is 400 microns. A spacing d between adjacent second interdigital structures  112  is 500 microns. Compared with the structure shown in  FIG.  4 B , the density of the interdigital structure is reduced in  FIG.  4 D . 
     Compared with the touch electrode structure without interdigital structures in  FIG.  4 A , the touch electrode structure shown in  FIGS.  4 B- 4 D  improves the density of electric field lines between the first touch electrode  111  and the second touch electrode  121  because the interdigital structure increases the coupling area between the first touch electrode  111  and the second touch electrode  121  in the same space, thus increasing the mutual capacity between the first touch electrode  111  and the second touch electrode  121 , thus improving the touch sensitivity of the touch electrode structure. 
     Comparing the touch electrode structures shown in  FIG.  4 B  and  FIG.  4 C , it can be known that increasing the length L of the interdigital structure also helps to increase the electric field line density between the first touch electrode portion  111  and the second touch electrode portion  121 , because increasing the interdigital structure helps to increase the coupling area between the first touch electrode  111  and the second touch electrode  121  in the same space, thus increasing the mutual capacity between the first touch electrode  111  and the second touch electrode  121 , thus increasing the touch sensitivity of the touch electrode. 
     Comparing the touch electrode structures shown in  FIG.  4 B  and  FIG.  4 D , it can be known that increasing the density of interdigital structures (i.e., reducing the spacing d between adjacent interdigital structures) is also helpful to increase the electric field line density between the first touch electrode  111  and the second touch electrode  121 , thus improving the touch sensitivity of the touch electrode structure. 
     For example, a length L 1  of each second interdigital structure  112  ranges from 1/10 to ⅓ of a center distance of adjacent first touch electrode portions  111 , that is, a distance between center points of adjacent first touch electrode portions  111 . For example, the center distance is a pitch P of the touch electrode structure. For an irregular interdigital structure, for example, the length L 1  may be an average length, a maximum length or a minimum length of the second interdigital structure  112 . 
     For example, a width L 2  of each second interdigital structure  112  ranges from 1/10 to ¼ of the center distance of the adjacent first touch electrode portions  111 , for example, 1/10-¼ of the pitch P of the touch electrode structure. For an irregular interdigital structure, for example, the width L 2  may be the average width, the maximum width or the minimum width of the second interdigital structure  112 . 
     For example, the spacing d between adjacent second interdigital structures  112  ranges from 1/20 to 1/10 of the pitch P of the touch electrode structure. In case of uneven spacing between adjacent interdigital structures, for example, the spacing d may be an average spacing, a maximum spacing or a minimum spacing of the second interdigital structure  112 . 
     The first touch electrode portion  111  is taken as an example to describe the touch electrode part provided in the embodiment of the present disclosure hereinafter, and such description is also applicable to the second touch electrode portion. 
       FIG.  5    shows an enlarged schematic diagram of a first touch electrode portion  111 . The first touch electrode portion  111  includes a second body portion  113  and a plurality of second interdigital structures  112  connected to the second body portion  113 , and the plurality of second interdigital structures  112  are distributed around the second body portion  113 . The second body portion  113  includes a plurality of edges, for example, the second body portion  113  is rectangular. For example, an amount of the second interdigital structures  112  corresponding to each edge is 3-10, such as 6-10. 
     For example, as shown in  FIG.  5   , the extending directions of at least one first interdigital structure  214  of the first dummy electrode  211  in the first touch electrode portion  111  and at least one second interdigital structure  112  of the first touch electrode portion  111  are parallel to each other. 
     For example, as shown in  FIG.  5   , an extending direction of the first interdigital structure  214  intersects both the first direction D 1  and the second direction D 2 . For example, an extending direction of the second interdigital structure  112  intersects both the first direction D 1  and the second direction D 2 . 
     For example, as shown in  FIG.  5   , on each edge of the first body portion of the first dummy electrode  211 , one of two adjacent first interdigital structures (A) points to one second interdigital structure  112 , and the other (B) points to a gap between two adjacent second interdigital structures  112 . That is to say, a center lines of the first interdigital structure A in the length direction and a center lines of the second interdigital structures  112  in the length direction are basically coincided, and a center line of the first interdigital structure B in the length direction is basically coincided with the center line between two adjacent second interdigital structures  112  (as shown by dashed lines in  FIG.  5   ). 
     For example, the second interdigital structure  112  may have a regular shape or an irregular shape, and may include at least one of rectangle, triangle, and trapezoid. As shown in  FIG.  5   , each second interdigital structure  112  has a convex shape, that is, a combination of two rectangles; this convex shape further increases the edge length of the first touch electrode portion  111  compared with the shape of a single rectangle. 
     As shown in  FIG.  5   , the first touch electrode portion  111  further includes an electrode connection part  114  at a position corresponding to a top corner of the second body portion  113 . For example, the electrode connection parts  114  corresponding to two top corners of the second body portion  113  along the first direction D 1  are electrically connected to the first touch electrode portions  111  adjacent to the first touch electrode portion  111  through the first connection parts to form the first touch electrode  110  along the first direction D 1  (refer to  FIG.  6 A ). 
     For example, the electrode connection part  114  is directly connected to the nearest second interdigital structure  112 . 
       FIG.  6 A  shows a schematic diagram of a touch unit in the touch electrode structure provided by an embodiment of the present disclosure. As shown in  FIG.  6 A , along the first direction D 1 , adjacent first touch electrode portions  111  are electrically connected to each other through the first connection portion  115  to form the first touch electrode  110 ; in the second direction D 2 , adjacent second touch electrode portions  121  are electrically connected to each other through the second connection portion  125  to form the second touch electrode  120 . For example, the first touch electrode portion  111 , the second touch electrode portion  121 , and the second connection portion  125  are located in the same layer and are separated from the first connection portion  115  by an insulating layer. 
     For example, as shown in  FIG.  6 A , the adjacent first touch electrode portions  111  are electrically connected to each other in the first direction D 1  by the first connection part  115 . For example, two first connection portions  115  are arranged between every two adjacent first touch electrode portions  111 , that is, a dual-channel structure is formed, which can effectively improve the product yield. For example, a position where the signal lines intersect is easy to cause short circuit defect due to electrostatic breakdown of the mutual capacitance, in the case where one channel of the two first connection portions  115  is detected to have short circuit defect in the detection process, the channel can be cut off (for example, by laser cutting), and the circuit structure can still work normally through the other channel. 
     For example, both of the second touch electrode  110  and the first touch electrode  120  may be block-shaped and made of transparent conductive materials. Both of them may include a grid structure, which is made of metal conductive materials. 
       FIG.  6 B  shows an enlarged schematic diagram of the touch unit at the intersection F of the first touch electrode portion  111  and the second touch electrode portion  121 . As shown in  FIG.  6 B , both the second touch electrode  110  and the first touch electrode  120  have a grid structure. In this figure, the bright mesh structure shows the first connection parts  115  located in the same layer, and the dark mesh structure shows the second touch electrodes  120  (including the second connection part  125  and the second touch electrode portion  121 ) located around the first connection parts  115  and in a different layer from the first connection parts  115 . Between adjacent first touch electrode portions  111 , two terminals of two first connection portions  115  are connected, for example, in an integrated network structure. The terminals of the first connection portions  115  respectively overlap with the first touch electrode portions  111  which are connected to the terminals of the first connection portions  115  in a direction perpendicular to the plane of the mesh structure and are electrically connected through the vias  103 . 
     The embodiment of the present disclosure also provides a touch panel, which comprises the above touch electrode structure. 
       FIG.  7    is a schematic diagram of a touch panel according to at least one embodiment of the present disclosure. As shown in  FIG.  7   , the touch panel  30  includes a touch region  301  and a non-touch region  302  located outside the touch region  301 , and the touch electrode structure  20  is located in the touch region  301 . For example, the touch region  301  is rectangular, and the length direction of the rectangle is along the first direction D 1  and the width direction is along the second direction D 2 . The first touch electrode  110  extends along the length direction of the rectangle, and the second touch electrode  120  extends along the width direction of the rectangle. For the sake of clarity, the structures of the first touch electrode and the second touch electrode are not shown in detail. 
     For example, as shown in  FIG.  7   , the touch panel  30  further includes a plurality of signal lines  130  located in the non-touch region  302 . Each first touch electrode  110  and each second touch electrode  120  are electrically connected to a signal line  130 , respectively, and are connected to a touch integrated circuit (not shown in the figure) through the signal line. For example, the first touch electrode  110  is a touch driving electrode and the second touch electrode  120  is a touch sensing electrode, but this is not limited by the embodiments of the present disclosure. 
     The touch integrated circuit is, for example, a touch chip, which is used to provide the touch driving signal to the first touch electrode  110  in the touch panel  30 , receive the touch sensing signal from the second touch electrode  120 , and process the touch sensing signal to realize a touch detection function. 
     For example, as shown in  FIG.  7   , an terminal of the plurality of signal lines  130  connected to the touch integrated circuit can be arranged on the same side of the touch region  301  (for example, a lower side in  FIG.  7   ), which can facilitate the connection with the touch integrated circuit. 
     For example, as shown in  FIG.  7   , because the first touch electrode  110  is longer than the second touch electrode  120 , in order to improve the signal transmission speed, a signal line  130  can be respectively arranged at both terminals of one first touch electrode  110 . During operation, the touch integrated circuit can bidirectionally input touch driving signals (bilateral driving) to one first touch electrode  110  through two signal lines  130 , so that the signal loading speed on the first touch electrode  110  can be improved, thereby improving the detection speed. 
     An embodiment of the present disclosure also provides an electronic device, including the touch electrode structure  20  or the touch panel  30 . For example, the electronic device is a touch display panel including a display panel. For example, the touch electrode structure is integrated or arranged outside the display panel. For example, the touch panel and the display panel are integrated in various ways, such as embedded, external, etc. 
       FIG.  8 A  shows a sectional view of an electronic device provided by an embodiment of the present disclosure. For example, the electronic device is a touch display panel  40 , which includes a touch panel  30  and a display panel  31 , and the display panel  31  and the touch panel  30  are stacked. The display panel  31  includes a display region  401  and a non-display region  401 . For example, the display region  401  and the touch region  301  are aligned to correspond to each other, and the non-display region  402  and the non-touch region  302  are aligned to correspond to each other. The display panel  31  and the touch panel  30  are fixed to each other by glue, for example, or integrally formed, that is, the touch panel  30  is directly formed on the display panel  31  with the display panel  31  as a base substrate. 
     For example, the display panel  31  may be a liquid crystal display panel, an organic light-emitting diode display panel, or an electronic paper display panel. 
       FIG.  8 B  shows a cross-sectional view of an electronic device provided by another embodiment of the present disclosure. As shown in  FIG.  8 B , the display panel  31  includes a substrate  50  and a light-emitting element  500  located on the substrate  50 . The light-emitting element  500  is, for example, an organic light-emitting diode display panel. For example, the substrate  50  includes a pixel circuit (not shown) for driving the light-emitting element  500  to emit light. The display panel  31  further includes an encapsulation layer  51  located on a side of the light-emitting element  500  away from the substrate  50 , and the touch electrode structure  20  is located on a side of the encapsulation layer  51  away from the substrate  50 . The encapsulation layer  51  is configured to seal the light-emitting element  500  to prevent external moisture and oxygen from penetrating into the light-emitting element and the driving circuit to cause damage to the device. For example, the encapsulation layer  51  includes an organic thin film or a structure in which organic thin films and inorganic thin films are alternately stacked. 
     For example, the touch electrode structure  20  is directly formed on the encapsulation layer  51 . For example, the first connection portion  115  in the touch electrode structure  20  is in direct contact with the encapsulation layer, and at least one insulating layer may be formed between the first connection portion  115  and the encapsulation layer  51 . 
     For example, as shown in  FIG.  8 B , the display panel  31  further includes a cover plate  50  located on a side of the encapsulation layer  51  away from the substrate  50 , and the cover plate  52  is, for example, a glass cover plate or an organic flexible cover plate. The touch electrode structure  20  is located between the encapsulation layer  51  and the cover plate  52 . 
     In other examples, a transparent protective layer (such as transparent optical adhesive) may be used instead of the cover plate  52  to protect the touch electrode structure  20 . 
     Embodiments of the present disclosure also provide a manufacture method for manufacturing the touch electrode structure  20 . The manufacture method at least comprises forming a first touch electrode and a second touch electrode; the first touch electrode extends along a first direction, and the second touch electrode extends along a second direction, and the first direction intersects with the second direction; a size of the first touch electrode in the first direction is greater than a size of the second touch electrode in the second direction; the first touch electrode and the second touch electrode intersect with each other to form a mutual capacitance for touch detection; the first touch electrode comprises a first hollow region, and the second touch electrode comprises a second hollow region, a hollow area of the first touch electrode is greater than a hollow area of the second touch electrode; the touch electrode structure also includes at least one first dummy electrode, which is located in the first hollow region and is arranged in the same layer as at least part of the first touch electrode, and the at least one first dummy electrode and the at least part of the first touch electrode are insulated from each other. 
     The manufacture method of the touch electrode structure provided by the embodiment of the present disclosure will be exemplarily explained with reference to  FIGS.  3 A- 3 B . 
     In an example, the manufacture method at least includes the following steps S 801 -S 803 . 
     Step S 801 , forming a first connection portion  115  on a base substrate  101 . 
     For example, a first conductive layer is formed on the base substrate  101  and patterned to form the first connection portion  115 . For example, the first conductive layer is made of metal materials or alloy materials, such as aluminum, molybdenum, copper, and silver. For example, the material of the first conductive layer is silver palladium copper alloy (APC). For example, the patterning process is a conventional photolithography process, including the steps of coating, exposing, developing, drying, etching, and the like of photoresist. 
     For example, referring to  FIG.  6 B , the first connection portion  115  may have a mesh structure. 
     For example, the base substrate  101  is a flexible substrate, which can be formed of a plastic material with excellent heat resistance and durability. For example, polyimide (PI), polycarbonate (PC), polyethylene glycol terephthalate (PET), polycarbonate, polyethylene, polyacrylate, polycarbonate, polyarylate, polyetherimide, polyethersulfone, polyethylene glycol terephthalate (PET), polyethylene (PE), polypropylene (PP), polysulfone (PSF), Polymethyl methacrylate (PMMA), cellulose triacetate (TAC), cyclic olefin polymer (COP), cyclic olefin copolymer (COC), and the like. Alternatively, the base substrate  101  may also be the display panel itself, in which case the touch electrodes are directly formed on the surface of the display panel to obtain an integrated touch display panel. 
     Step S 802 : forming an insulating layer  102  on the first conductive layer and form a via  103  in the insulating layer. For example, the via  103  respectively correspond to the first connection portion  115  and expose at least part of the first connection portion  115  respectively. For example, each first connection portion  115  correspondingly forms two vias  103 . 
     For example, the material forming the insulating layer  102  can be an inorganic insulating material, for example, the inorganic insulating material is a transparent material. For example, the inorganic insulating material is silicon oxide, such as silicon oxide, silicon nitride and silicon oxynitride, silicon nitride or silicon oxynitride, or aluminum oxide, titanium nitride and other insulating materials including metal oxynitride. 
     For example, the material forming the insulating layer  102  may also be an organic insulating material to obtain good bending resistance. For example, the organic insulating material is a transparent material. For example, the organic insulating material is OCA optical adhesive. For example, the organic insulating material may include polyimide (PI), acrylate, epoxy resin, polymethyl methacrylate (PMMA), etc. 
     Step S 803 : forming a second conductive layer on the insulating layer  102  and patterning the second conductive layer to form the first touch electrode portion  110  and the second touch electrode  120 . 
     For example, a plurality of spaced first touch electrode portions  111  are formed along the first direction D 1  corresponding to the first connection portion  115 , and second touch electrodes  120  (including second touch electrode portions  121  and second connection portions  125 ) are formed along the second direction D 2 . An orthographic projection of each first connection portion  115  on the base substrate  101  is located between orthographic projections of two adjacent first touch electrode portions  111  on the base substrate  101  in the first direction D 1 . Each first touch electrode portion  111  is electrically connected to the corresponding first connection portion  125  through the via  103  to form the first touch electrode  110  extending along the first direction D 1 . A plurality of first touch electrodes  110  and a plurality of second touch electrodes  120  intersects with each other to form a plurality of touch units. 
     For example, the second conductive layer is patterned to form a first touch electrode portion  111  and a second touch electrode  120  which are insulated from each other, and a first hollow region  210  is formed in the first touch electrode. 
     In other examples, the second conductive layer is patterned to form the first touch electrode portion  111  and the second touch electrode  120  which are insulated from each other, and at least one dummy electrode is formed in the first touch electrode, which is insulated from each other at intervals. That is, the patterning process directly forms the first dummy electrode  210  located in the first hollow region. For example, the patterning process etches the whole conductive block into a first part and a second part which are insulated from each other, and the first part is located in the second part to form the dummy electrode; the second part surrounds the first part and forms the first touch electrode portion  111 . 
     For example, the patterning process may form a plurality of first dummy electrodes  210  spaced apart from each other, that is, the first hollow region  210  may include a plurality of first sub-hollow regions  212  spaced apart from each other; the plurality of first dummy electrodes  211  are respectively formed in a one-to-one correspondence in a plurality of first sub-hollow regions  212 . 
     For example, the first hollow region  210  can be formed in the first touch electrode, while the second hollow region and the second dummy electrode can be formed in the second touch electrode, which will not be described in detail here. 
     For example, the hollow area of the first touch electrode  110  is greater than the hollow area of the second touch electrode  120 . 
     In some examples, the hollow region may be formed only in the first touch electrode and not in the second touch electrode, so that the process may be simplified. 
     For example, the material of the second conductive layer is a transparent conductive material including transparent conductive metal oxide materials, such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), zinc aluminum oxide (AZO), indium gallium zinc oxide (IGZO), etc. 
     For example, the material of the second conductive layer may also be a metal material, such as aluminum, molybdenum, copper, silver and other metal materials or alloy materials. 
     What have been described above merely are specific implementations of the present disclosure, but the protective scope of the present disclosure is not limited to this case. The protective scope of the present disclosure is determined by the appended claims.