Circuit boards and electronic devices

Abstract

To provide a circuit board and an electronic apparatus which can extend the service life of a steel mesh when printing tin paste on the circuit board.SOLUTION: A metal layer 20 on a substrate 10 is divided by a first slit 21 into at least two first regions 221 and second regions 222 which are alternately distributed in the row and column directions and insulated from each other, and each row-direction second slit 212 in the first region 221 is divided by a first extension portion A1 extending in the column direction from at least a portion of the metal sheet in the first region 221, and each column-direction second slit 212 in the second region 222 is divided by a second extension portion A2 extending in the row direction from at least a portion of the metal sheet in the second region 222.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] This application relates to the field of chip packaging technology, and more particularly to circuit boards and electronic devices. [Background technology]

[0002] SMT (Surface Mounted Technology) is the most widespread technology and process in the electronic packaging industry. It is a circuit mounting connection technology in which leadless or short-lead surface mount components (abbreviated as SMC (Surface Mounted Components) / SMD (Surface Mounted Devices)) are mounted on the surface of a PCB (Printed Circuit Board) or other substrate and soldered using methods such as reflow soldering or dip soldering. As electronic devices have become increasingly miniaturized, SMT has become widely used in electronic device manufacturing.

[0003] The steel mesh is a special mold for surface mount technology, whose main function is to assist in the deposition of tin paste, transferring precise amounts of tin paste to corresponding pad locations on a printed circuit board. Conventional printed circuit board structures typically involve slits in the metal layer of the board, dividing the metal layer into multiple metal sheets insulated from each other to form corresponding traces, and then providing pads and a solder resist layer covering the traces (with the pads exposed through the solder resist layer) at corresponding locations on the traces. Specifically, as shown in Figure 1, the printed circuit board has a horizontally extending slit C1 and a vertically extending slit C2. Here, the vertically extending slits C2 continuously span multiple metal sheets in the vertical direction, forming long vertical slits. In the process of printing solder on a printed circuit board, after solder is applied to the steel mesh, when a knife is moved over the steel mesh, the steel mesh will deform and sink as it passes through the vertical slits C2 due to its lack of strong supporting force, and will adhere to the surface of the board. If the depression in the steel mesh is too large, it will easily be damaged. If the steel mesh is damaged during the soldering process, the accuracy of solder application cannot be ensured. Summary of the Invention

[0004] In view of the disadvantages of the above-mentioned conventional techniques, the object of the present application is to provide a circuit board and an electronic device that can reduce the depressions in the steel mesh when printing tin paste on the circuit board, thereby extending the service life of the steel mesh.

[0005] In order to achieve the object of the application, the present application provides the following technical means.

[0006] The present application relates to a circuit board comprising at least one substrate and a metal layer disposed on the front and / or rear surface of the substrate, wherein the metal layer has a region array including at least two first regions and at least two second regions separated by a first slit, the first regions and the second regions being alternately distributed in both the row and column directions of the region array and insulated from each other; Each of the first area and the second area has at least two metal sheets insulated from each other and formed by dividing them by a second slit, and pads for connecting to one electronic component are provided corresponding to two adjacent metal sheets in each of the first area and the second area, and the pads in each of the first area and the second area are arranged in an array of a plurality of rows and columns on the substrate to form a pad array; The present invention provides a circuit board in which at least a portion of the metal sheet in each of the first regions has a first extension portion extending in the column direction of the pad array, and the second slits are divided by the first extension portion in each row direction of the pad array in each of the first regions, and at least a portion of the metal sheet in each of the second regions has a second extension portion extending in the row direction of the pad array, and the second slits are divided by the second extension portion in each column direction of the pad array in each of the second regions.

[0007] Based on the same inventive concept, the present application provides an electronic device including a circuit board as described above and electronic components provided on the circuit board and soldered to the corresponding pads. [Effects of the Invention]

[0008] In the circuit board provided by the present application, at least a portion of the metal sheet in each of the first regions has a first extension portion extending in the column direction of the pad array, and the second slits are divided by the first extension portion in each row direction of the pad array in each of the first regions, and at least a portion of the metal sheet in each of the second regions has a second extension portion extending in the row direction of the pad array, and the second slits are divided by the second extension portion in each column direction of the pad array in each of the second regions.

[0009] The metal layer on the substrate is divided by a first slit into at least two first regions and two second regions that are alternately arranged in the row and column directions and are insulated from each other, forming an area array; the metal layer in each of the first and second regions is divided by a second slit into at least two metal sheets that are insulated from each other, and pads for connecting to one electronic component are provided correspondingly on two adjacent metal sheets to form wiring on the circuit board, which is simple and efficient in forming wiring; The pads in each of the first and second regions are arranged on the substrate in an array of a plurality of rows and columns to form a pad array, and at least a portion of the metal sheet in each of the first regions has a first extension portion extending in the column direction of the pad array, and in each row direction of the pad array in each of the first regions, second slits are divided by the first extension portion to form support points that support the steel mesh in each row direction, and at least a portion of the metal sheet in each of the second regions has a second extension portion extending in the row direction of the pad array, and in each column direction of the pad array in each of the second regions, second slits are divided by the first extension portion to form support points that support the steel mesh in each column direction. The second slits are interrupted by the second extensions to form support points for supporting the second slits, thereby ensuring sufficient support points in both the row and column directions of the pad array, thereby minimizing the degree of deformation of the steel mesh at the positions of the second slits during solder printing, for example minimizing the degree of depression of the steel mesh at the positions of the second slits, extending the service life of the steel mesh, improving the accuracy of solder coating, and reducing steel mesh loss and costs.Furthermore, the present application only requires sophisticated improvements to the distribution of the second slits, without the need to add any other parts or processes, making it easy to manufacture, versatile, and low-cost.

[0010] The present application provides an electronic device using the circuit board, in which the distribution of second slits on the circuit board can reduce the degree of deformation of the steel mesh at the positions of the second slits during solder printing, thereby minimizing damage to the steel mesh due to excessive depression at the positions of the second slits, and further ensuring the accuracy of the solder printed using the steel mesh, thereby improving the reliability and yield of the circuit board and electronic device. [Brief explanation of the drawings]

[0011] In order to more clearly describe the embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings used in the description of the embodiments or the prior art. Of course, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can further obtain other drawings based on these drawings without any creative work. [Figure 1] FIG. 1 is a diagram illustrating the configuration of a conventional printed circuit board. [Figure 2] 1 is a top view of the surface of a circuit board provided by an embodiment of the present application. [Figure 3] 1 is a schematic cross-sectional view of a circuit board provided by an embodiment of the present application. [Figure 4] 2 is a schematic cross-sectional view of a circuit board provided by an embodiment of the present application. [Figure 5] 3 is a schematic cross-sectional view of a circuit board provided by an embodiment of the present application. [Figure 6] 2 is a top view 2 of the surface of a circuit board provided by an embodiment of the present application. [Figure 7] 3 is a top view of the surface of a circuit board provided by an embodiment of the present application. [Figure 8] 1 is a top view of an LED chip mounted on a circuit board provided according to an embodiment of the present application. DETAILED DESCRIPTION OF THE INVENTION

[0012] To facilitate understanding of the present application, the present application will now be described more fully with reference to the accompanying drawings. The drawings illustrate preferred embodiments of the present application. However, the present application is not limited to the embodiments set forth herein, and may be embodied in various forms. On the contrary, these embodiments are provided to provide a more complete understanding of the subject matter disclosed herein.

[0013] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0014] Hereinafter, the technical solutions in the embodiments of the present application will be described clearly and completely with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without creative work also fall within the protection scope of the present application.

[0015] 2 and 3 are schematic diagrams of a circuit board provided by this embodiment, where FIG. 2 is a top view of the surface of the circuit board, and FIG. 3 is a schematic cross-sectional view of two adjacent metal sheets in FIG. 2 . This embodiment provides a circuit board including a substrate 10 and a metal layer 20 disposed on the substrate 10. While FIGS. 2 and 3 show the metal layer disposed on the surface of the substrate, it should be understood that the metal layer 20 may be disposed on the back surface of the substrate 10, or that the metal layer 20 may be disposed on both the front and back surfaces of the substrate 10. For ease of understanding, the following description will be given using an example in which the metal layer 20 is disposed on the front surface of the substrate 10. The substrate 10 in this embodiment is an insulating substrate, and the material of the substrate 10 may be determined depending on the application scenario of the circuit board. For example, if the circuit board needs to be bent, the substrate 10 may be made of a flexible material such as epoxy resin, which has good heat dissipation properties, is thin, can be bent, folded, and rolled, and can be freely moved and expanded in three-dimensional space, allowing for the formation of a three-dimensional circuit board. When the circuit board is required to have a certain level of support, the substrate 10 can be made of a rigid material such as a ceramic substrate having a certain level of mechanical strength.

[0016] In this embodiment, the metal layer 20 may be a conductive layer such as copper foil or aluminum foil, and the metal layer 20 has slits 21 formed therein. The slits 21 include first slits 211 that divide the metal layer 20 into at least two first regions 221 and at least two second regions 222. The first slits 211 penetrate the front and back surfaces of the metal layer 20 (i.e., the bottom of the first slit 211 is the front surface of the substrate 10. Note that the first slits are not specifically shown in FIG. 2 , and the reference numeral 211 in FIG. 2 indicates an example of the location where the first slits are provided). The formed at least two first regions 221 and at least two second regions 222 constitute a region array of the metal layer 20. As shown in FIG. 2 , the first regions 221 and the second regions 222 are alternately distributed in both the row direction (X direction in FIG. 2 , hereinafter also referred to as the horizontal direction) and the column direction (Y direction in FIG. 2 , hereinafter also referred to as the vertical direction) of the region array, and are insulated from each other. 2, for example, the region array is a 2*2 array, in which the first row of the region array is sequentially provided with the first region 221 and the second region 222, the second row of the region array is sequentially provided with the second region 222 and the first region 221, the first column of the region array is sequentially provided with the first region 221 and the second region 222, and the second column of the region array is sequentially provided with the second region 222 and the first region 221, and adjacent first regions 221 and second regions 222 are separated and insulated from each other by first slits 21. It should be understood that the region array shown in FIG. 2 is merely an example for ease of understanding, and in actual applications, it may be configured as an N*M array, where N and M are 2 or more, and the values ​​of N and M may be equal or unequal.

[0017] 2, in this embodiment, the slit 21 further includes a second slit 212 that divides the metal layer 20 into at least two metal sheets 22 in each of the first region 221 and the second region 222. The second slit 212 also penetrates the front and back surfaces of the metal layer 20 (i.e., the bottom of the second slit 212 is the front surface of the substrate 10, and the reference numeral 212 in FIG. 2 indicates an example of the planar structure of the second slit), insulating adjacent metal sheets 22 from each other. One pad 23 is provided corresponding to each of the two adjacent metal sheets 22 in each of the first region 221 and the second region 222, so that the two adjacent metal sheets 22 are located on both sides of the second slit 212. For example, one pad 23 can be provided corresponding to each of the edges or regions near the edges of the two adjacent metal sheets 22. The two corresponding pads 23 may be a positive electrode pad and a negative electrode pad, respectively, and are used to connect the positive electrode lead and the negative electrode lead of the same electronic component. 2, in this embodiment, the pads 23 in each of the first region 221 and the second region 222 are combined into a pad array with multiple rows and columns on the substrate 10. In the example shown in FIG. 2, the array of pads 23 formed in each of the first region 221 and the second region 222 is a 12*8 array, i.e., 12 rows and 8 columns. It should be understood that the pad array shown in FIG. 2 is also just an example for ease of understanding, and in actual applications, the pad array may be set to an n*m array, where n and m are 2 or more, and the values ​​of n and m may be equal or unequal.

[0018] As shown in FIG. 2 , in this embodiment, at least a portion of the metal sheet 22 in each first region 221 has a first extension portion A1 extending in the column direction of the pad array, and in each row direction of the pad array in each first region 221, the second slits 212 are divided by the first extension portion A1, so that in each row direction, the first extension portion A1 forms a support point for supporting the steel mesh; and at least a portion of the metal sheet 22 in each second region 222 has a second extension portion A2 extending in the row direction of the pad array, and in each column direction of the pad array in each second region 222, the second slits 212 are divided by the second extension portion A2, so that Therefore, in each column direction, the second extension portions A2 form support points for supporting the steel mesh, thereby ensuring that the steel mesh is supported by sufficient support points in both the row and column directions of the pad array, thereby minimizing the degree of deformation of the steel mesh during printing solder at the position of the second slits 212, extending the service life of the steel mesh, improving the accuracy of solder coating, and reducing steel mesh loss and costs. In the example shown in Figure 2, by simply adjusting the distribution of the second slits 212, no additional parts or processes are required, resulting in simple manufacturing, good versatility, and low cost.

[0019] In some examples of this embodiment, at least one of the first slit 211 and the second slit 212 may be formed by etching the metal layer 20, but is not limited to this, and the etching process is simple, mature, and has high efficiency and yield.

[0020] In some examples of this embodiment, the pads 23 formed at positions corresponding to the edges of two adjacent metal sheets 22 in each of the first region 221 and the second region 222 may be arranged symmetrically in the X direction, thereby being arranged in a plurality of rows and columns. However, it should be understood that in this embodiment, the pads 23 correspondingly arranged on two adjacent metal sheets 22 are not limited to being arranged symmetrically and may be arranged asymmetrically as necessary. In this embodiment, the number of pads 23 included in each of the first region 221 and the second region 222 is equal. Of course, it should be understood that the number of pads 23 included in each of the first region 221 and the second region 222 may be different.

[0021] In this embodiment, in the same column direction Y, the second slits 212 in the second region 222 are divided by the metal sheets 22 of the second region 222 along the second extension portions A2 in the row direction, so that the length D2 of one second slit 212 in the same column direction Y is shorter than the length D1 of one second slit 212 in the first region 221 in the same column direction Y (here, D1 and D2 are, as shown in Figure 2, in Figure 2, the second slits 212 extending along the column direction in the first region 221 span multiple metal sheets 22). By arranging a configuration in which the length D1 of the second slit 212 in the first region 221 and the length D2 of the second slit 212 in the second region 222 are different (i.e., in each column direction, the second slit 212 in the second region 222 is divided along the second extension portion A2 in the row direction by the metal sheet 22 in the second region 222, and the second slit 212 in the first region 221 spans multiple metal sheets 22) in the same column direction Y, when printing solder using the steel mesh, the support strength in the same straight line direction in the column direction of the steel mesh is increased, with each second extension portion A2 serving as a support point. Similarly, in the same row direction X, the second slits 212 in the first region 221 are divided by the metal sheets 22 in the first region 221 along the first extension portions A1 in the column direction, so the length D3 in the same row direction X of one second slit 212 in the second region 222 is shorter than the length D4 in the same row direction X of one second slit 212 in the second region 222 (here, D3 and D4 are, as shown in Figure 2, the second slits 212 extending in the row direction of the second region 222 span multiple metal sheets 22).By arranging a configuration in which the length D3 of the second slits 212 in the first region 221 and the length D4 of the second slits 212 in the second region 222 are different (i.e., in each row direction, the second slits 212 in the first region 221 are separated by the metal sheet 22 in the first region 221 along the first extension portion A1 in the column direction, but the second slits 212 in the second region 222 are formed across multiple metal sheets 22) in the same row direction X, when printing solder using the steel mesh, each first extension portion A1 serves as a support point, and the support strength in the same straight line direction in the row direction of the steel mesh is increased, thereby reducing the depression of the steel mesh when printing solder in both the row direction and the column direction, and extending the service life of the steel mesh.

[0022] As can be appreciated, in other embodiments, the length D1 of the second slits 212 in the first region 221 may be shorter than the length D2 of the second slits 212 in the second region 222, and the length D3 of the second slits 212 in the first region 221 may be longer than the length D4 of the second slits 212 in the second region 222. For example, FIG. 6 shows a configuration in which the alternating arrangement of the first region 221 and the second region 222 shown in FIG. 2 is reversed.

[0023] As can be understood, the row direction and column direction in this embodiment are two relative concepts, such that the rows in Fig. 2 become the columns in Fig. 7 and the columns in Fig. 2 become the rows in Fig. 7, as in the case where the circuit board shown in Fig. 2 is rotated to obtain Fig. 7. That is, in another embodiment, when the column direction in Fig. 2 is rotated and converted into the row direction in Fig. 7, in Fig. 7, the length D5 (corresponding to D1 in Fig. 2) of the second slit 212 in the first region 221 in the same row direction X is longer than the length D6 (corresponding to D2 in Fig. 2) of the second slit 212 in the second region 222, and the length D7 (corresponding to D3 in Fig. 2) of the second slit 212 in the first region 221 in the same column direction Y is shorter than the length D8 (corresponding to D4 in Fig. 2) of the second slit 212 in the second region 222.

[0024] 2 and 3, in the same column direction Y, the second slits 212 in the second region 222 are divided by the metal sheet 22 in the second region 222 along the second extending portion A2 extending in the row direction, and therefore the number of second slits 212 extending in the column direction Y in the first region 221 is smaller than the number of second slits 212 extending in the column direction Y in the second region 222. In the example shown in FIG. 2, in the same column direction Y (taking the first column from left to right as an example), the number of second slits 212 in the first region 221 (see K1 in FIG. 2) is 1, and the number of second slits 212 in the second region 222 (see K2, K3, and K4 in FIG. 2) is 3.

[0025] 2, the second slits 212 in the first region 221 and the second region 222 include a plurality of trunk slits extending linearly in the row direction X or the column direction Y, and a plurality of branch slits connecting to the trunk slits by separating the pads 23 between adjacent metal sheets 22, and each trunk slit is connected to at least two branch slits. The trunk slits in the first region 221 are not parallel to the extending direction of the trunk slits in the second region 222. Specifically, as shown in Figure 2, the first region 221 has six trunk slits Z11, Z12, Z13, Z14, Z15, and Z16 extending in the column direction Y, and each trunk slit has three branch slits connected to one side thereof. For example, the three branch slits connected to trunk slit Z16 are x11, x12, and x13, respectively, and at least a portion of each branch slit is perpendicular to the trunk slit. The second region 222 has four trunk slits Z21, Z22, Z23, and Z24 extending in the row direction X, and each trunk slit has three branch slits connected to one side thereof. For example, the three branch slits connected to trunk slit Z24 are X21, X22, and X23, respectively, and each branch slit has a portion parallel to the trunk slit and a portion perpendicular to the trunk slit, and a bending angle is formed at the connection point between the portion parallel to the trunk slit and the portion perpendicular to the trunk slit. As can be seen from FIG. 2, the trunk slits in the first region 221 are perpendicular to the extension direction of the trunk slits in the second region 222, and there are more support points in the extension direction of the trunk slits between the first region 221 and the second region 222, which reduces the degree of depression of the steel mesh when printing tin paste on the circuit board and extends the service life of the steel mesh.

[0026] In this embodiment, for example, as shown in FIG. 2, a support region 24 is provided between adjacent first and second regions 221 and 222. When the knife moves over the steel mesh and passes through the region between the adjacent first and second regions 221 and 222, a force is applied to the steel mesh in a vertical downward direction of the substrate 10. The support region 24 can support the steel mesh so as to reduce the degree to which the steel mesh is depressed and deformed in the region between the adjacent first and second regions 221 and 222, thereby better preventing damage to the steel mesh and extending the useful life of the steel mesh.

[0027] In this embodiment, for a single first region 221, the first slit 211 is located at the edge of the first region 221, and the second slit 212 is located inside the first region 221, with the first slit 211 and the second slit 212 being connected to each other so as to surround the first region 221. The first slit 211 isolates the first region 221 from an external circuit outside the first region 221, and the second slit 212 isolates two adjacent metal sheets in the first region 221. For a single second region 222, the first slit 211 is located at the edge of the second region 222, and the second slit 212 is located inside the second region 222, with the first slit 211 and the second slit 212 being connected to each other so as to surround the second region 222. The first slit 211 isolates the second region 222 from an external circuit outside the second region 222 , and the second slit 212 isolates two adjacent metal sheets in the second region 222 .

[0028] In this embodiment, the width of the second slits 212 located within the first region 221 and the second region 222 can be determined according to the spacing between the pins of the electronic device to be soldered to the pads 23 on both sides thereof and the size of the metal sheet 22, and the width of the first slits 211 located on the edges of the first region 221 and the second region 222 can be set according to actual needs (e.g., voltage, current, etc. on the circuit board). In this embodiment, the width of the first slits 211 is smaller than the width of the second slits 212. By providing the first slits 211 at the edges of the first region 221 and the second region 222, the wiring in the first region 221 and the second region 222 can be isolated from the external circuits of the first region 221 and the second region 222. By providing the second slits 212 inside the first region 221 and the second region 222, adjacent metal sheets can be isolated to form desired circuits. In addition, the direction and width of the first slits 211 and the second slits 212 can be rationally designed according to the needs of the circuits, thereby maximizing the supporting effect of the metal layer 20 and achieving the purpose of further reducing the degree of depression of the steel mesh.

[0029] In some examples of this embodiment, the extension direction of at least one of the first slits 211 and the second slits 212 shown in Fig. 2 is the same as the row direction and column direction of the pad array, which may be understood to be the same as the X direction and Y direction shown in Fig. 2. In the example shown in Fig. 2, the second slit 212 extends in a serpentine manner. For example, the second slit 212 extends in a serpentine manner in the row direction X and the column direction Y, and forms right angles at the corners of the extension path (of course, rounded corners or other types of corners may be used instead). By making the second slit 212 serpentine in the row direction X and the column direction Y so that the multiple metal sheets 22 or a combination of multiple metal sheets 22 form a rectangle, the layout design of the electronic component during packaging becomes easier.

[0030] As can be appreciated, in other embodiments, the second slits 212 may extend in a serpentine manner in other directions to divide the metal layer 20 into metal sheets of other shapes, such as circular, trapezoidal, diamond, triangular, etc., to accommodate electronic components of different shapes or sizes.

[0031] 2, the first slits 211 also extend in a serpentine manner, and the first slits 211 extend in a serpentine manner in the row direction X and the column direction Y, surrounding the plurality of metal sheets 22 with rectangular first regions 221 and second regions 222, which facilitates the layout design of the electronic components during packaging. As can be appreciated, in other embodiments, the first slits 211 may extend in other directions following the extension path of the second slits 212, and together with the second slits 212, form the first regions 221 and second regions 222 in any shape, such as a circle, a trapezoid, a rhombus, a triangle, etc.

[0032] In another example of this embodiment, referring to FIG. 3 , the slits 21 (i.e., the first slits 211 and the second slits 212) are filled with a solder resist layer 30, and the height of the solder resist layer 30 is lower than the height of the metal sheet 22 in a direction perpendicular to the substrate 10. The solder resist layer 30 serves both as an insulator and as a solder resist. For example, in this embodiment, the material of the solder resist layer 30 is solder resist ink. However, in other embodiments, the solder resist layer 30 may be made of solder resist, solder resist, or the like. Furthermore, in the circuit board mounting process, the pads 23 for fixing electronic components to the pads 23 require tin plating. Since the spacing between adjacent pads 23 is narrow, filling the slits 21 with the solder resist layer 30 that separates the different metal sheets 22 can prevent mutual interference between the electronic components due to solder bridging between adjacent pads 23. The solder resist layer 30 also serves to prevent solder from spilling out and shorting during the reflow soldering process. Furthermore, by providing the solder resist layer 30, even if the steel mesh is dented at the positions of the first slit 211 and the second slit 212, the most dented part will only overlap the solder resist layer 30, and the degree of denting of the steel mesh can be further reduced compared to a configuration in which the solder resist layer 30 is not provided at the first slit 211 and the second slit 212, thereby extending the service life of the steel mesh.

[0033] In yet another example of this embodiment, a metal layer may be provided on both the front and back surfaces of the substrate, and the metal layers provided on both the front and back surfaces may be the metal layer 20 shown in FIG. 2, or only one of the metal layers may be the metal layer 20 shown in FIG. 2. For example, as shown in FIG. 4 (FIG. 4 is also a schematic cross-sectional view including two adjacent metal sheet portions), the front surface of the substrate 10 is a first surface 11, and the back surface of the substrate 10 is a second surface 12. It should be understood that the front and back surfaces of the substrate 10 are relative to each other. A first metal layer 201 is provided on the first surface 11, and a second metal layer 202 is provided on the second surface 12. Circuits are provided on the first surface 11 and the second surface 12 on the opposite side of the substrate 10, and electronic components are mounted on them, and the configuration of at least one of the first metal layer 201 and the second metal layer 202 is the same as the metal layer 20 shown in FIG. 2. For example, if the configurations of the first metal layer 201 and the second metal layer 202 are the same as the configuration of the metal layer 20 shown in FIG. 2 , the purpose of reducing dents in the steel mesh on both the front and back surfaces of the circuit board when solder is printed thereon can be achieved. As can be understood, the term "the structure of at least one of the first metal layer 201 and the second metal layer 202 is the same as the structure of the metal layer 20" specifically includes the following: the structure of only the first metal layer 201 is the same as the structure of the metal layer 20 provided by the embodiment of the present application; the structure of only the second metal layer 202 is the same as the structure of the metal layer 20 provided by the embodiment of the present application; or the structure of both the first metal layer 201 and the second metal layer 202 are the same as the structure of the metal layer 20 provided by the embodiment of the present application. In this example, there may be no circuit connection between the first metal layer 201 and the second metal layer 202, or a circuit connection may be made as needed. For example, referring to the example of Figure 4, the substrate 10 has a via 13 penetrating the first surface 11 and the second surface 12 of the substrate 10, and the first metal layer 201 and the second metal layer 202 are connected by the via 13 (i.e., the metal layers on the front and back surfaces of the substrate 10 are electrically connected by the via 13).It should be understood that various methods can be used to connect the circuits on the first metal layer 201 and the second metal layer 202 using the via 13. For example, the circuits on both sides of the via 13 may be electrically connected by electroless plating and re-plating, a conductive wire may be passed through the via 13 to connect the circuits on both sides of the via 13, or a conductive material may be filled in the via 13 and contact the first metal layer 201 and the second metal layer 202 simultaneously to achieve electrical connection. Examples of conductive materials include conductive paste, conductive ink, solder, etc. By opening the via 13 in the substrate 10 to connect the circuits on the first metal layer 201 and the second metal layer 202, it is possible to simplify the circuit configuration, avoid wiring routing, and save space.

[0034] In another example of this embodiment, the circuit board includes at least two laminated substrates, each having a metal layer. That is, in this example, the circuit board may have a multi-layer circuit board structure having at least two substrates and metal layers provided on the substrates. It should be understood that in this example, all of the metal layers provided on each substrate may have the configuration of metal layer 20 shown in FIG. 2, or some of the metal layers may have the configuration of metal layer 20 shown in FIG. 2, or some may have a different configuration.

[0035] In this example, when the circuit board has at least two stacked substrates, the adjacent substrates may be bonded by, but not limited to, an adhesive layer, and the bonding means is simple and reliable. It should be understood that in this example, the metal layers on each substrate do not need to have a direct electrical connection, and at least some of the metal layers between the substrates may be electrically connected as needed, and the electrical connection method may be, but is not limited to, providing corresponding vias in the substrates or providing connecting lines on the surface of the substrates or outside the substrates.

[0036] For ease of understanding, this example will be described with reference to a multilayer circuit board structure shown in FIG. 5 (a schematic cross-sectional view including two adjacent metal sheet portions as shown in FIG. 5), in which two substrates 10, referred to here as a first substrate 101 and a second substrate 102, are bonded together by an adhesive layer 40. The first substrate 101 is provided with a first metal layer 201 and pads 23 to form a first sub-circuit board, and the second substrate 102 is provided with a second metal layer 202 and pads 23 to form a second sub-circuit board, and at least one of the first metal layer 201 and the second metal layer 202 has the structure of the metal layer 20 shown in FIG. 2. That is, the circuit board shown in FIG. 5 includes two substrates 10 and an adhesive layer 40 that bonds the two substrates 10 together, and the metal layer shown in FIG. 2 is provided on each of the two substrates 10 on the side away from the adhesive layer 40. The circuit board shown in FIG. 5 further includes a via 13 that penetrates at least the first substrate 101, the adhesive layer 4, and the second substrate 102, and the via 13 electrically connects the first metal layer 201 and the second metal layer 202.

[0037] It should be understood that when there is a high demand for multi-functionality in electronic devices, a large number of wiring layers is also required, but by providing a circuit board structure consisting of at least two substrates 10 and at least two metal layers 20, interference of transmission signals between different wiring in the multi-layer wiring structure can be avoided, and applying the circuit board provided by the present application to a multi-layer circuit board can contribute to reducing manufacturing costs in the steel mesh printing process. It should also be understood that in other examples, the number of substrates 10 and metal layers 20 may be other combinations and is not limited here.

[0038] An embodiment of the present application provides an electronic device including electronic components and the circuit board described above. The electronic components are mounted on the circuit board and soldered to corresponding pads. For example, the electronic components may be directly soldered to pads 23. The electronic components in this embodiment may be at least one of a capacitor, a resistor, an LED chip, etc., and may be electronic components having positive and negative leads. The positive and negative leads may be fixed to pads 23 by printing tin paste on pads 23 using a steel mesh and then soldering the tin paste (which may be an alternative to fixing with a conductive adhesive). By using a circuit board provided by an embodiment of the present application, the distribution of second slits on the circuit board can reduce the degree of deformation of the steel mesh at the positions of the second slits during solder printing, thereby minimizing damage to the steel mesh due to excessive depressions at the positions of the second slits. This also ensures the accuracy of the solder printed using the steel mesh, improving the reliability and yield of the circuit board and electronic device, and reducing the manufacturing cost of the electronic device.

[0039] The circuit board provided by this embodiment is a circuit board used in the display panel of an electronic device as a backlight for the display panel. In this application scenario, LED chips can be soldered to each pad in each first region and second region on the circuit board, and all LED chips in each first region and second region are connected in series. The LED chips in one first region are combined into one LED chip array, and the LED chips in one second region are also combined into one LED chip array, and the LED chips in each first region and each second region are combined into one large LED chip array on the board. For ease of understanding, the following description will use an example of soldering an LED chip L to the circuit board shown in FIG. 2. However, as shown in FIG. 8, the LED chip L is soldered to the pads 23 in each first region 221 and each second region 222 on the circuit board. 8, in the LED chip array consisting of the LED chips L in the first region 221, the pad at the upper right corner is a positive electrode pad H+ and the pad at the lower left corner is a negative electrode pad H-. Each LED chip L in the first region 221 forms a series circuit with each metal sheet 22 in the first region 221. For the current flow in the series circuit, see the dashed line indicated by I1 in Fig. 8. In the LED chip array consisting of the LED chips L in the second region 222, the pad at the upper right corner is a positive electrode pad H+ and the pad at the lower left corner is a negative electrode pad (not shown). Each LED chip L in the second region 222 forms a series circuit with each metal sheet 22 in the second region 222. For the current flow in the series circuit, see the dashed line indicated by I2 in Fig. 8.

[0040] 2, at least two first regions 221 and two second regions 222 are provided alternately in both the horizontal and vertical directions on the circuit board, and the display panel can be divided into at least two sub-regions. Therefore, the LED chips in the same region (e.g., in a certain first region 221 or a certain second region 222) can be controlled simultaneously, and the LED chips in the same region can be controlled individually as a whole. That is, the brightness of a certain sub-region of the display panel can be adjusted by individually controlling the brightness of the LED chips in a certain region, thereby realizing the effect of partial region dimming and improving the display effect of the display panel.

[0041] What has been disclosed above is merely a preferred embodiment of the present application, and of course, this does not limit the scope of the present application. Those skilled in the art can realize all or part of the flow of the above-mentioned embodiment, and understand that equivalent modifications to the scope of the present application will fall within the scope of the present application.

Claims

1. A circuit board comprising: an insulating substrate made of at least one flexible material and capable of being bent; and a metal layer disposed on a front surface and / or a back surface of the insulating substrate, wherein the metal layer has a region array, the region array being an N×M array where N and M are both 2 or greater, the region array including at least two first regions and at least two second regions divided by first slits, the first regions and the second regions being alternately distributed in both the row direction and the column direction of the region array and insulated from each other; Each of the first area and the second area has at least two metal sheets that are insulated from each other and are divided by a second slit, and pads for connecting to one electronic component are provided so as to correspond to two adjacent metal sheets in each of the first area and the second area, and the pads in each of the first area and the second area are arranged in an array of a plurality of rows and a plurality of columns on the insulating substrate to form a pad array, and the pad array is an n x m array, and both n and m are 2 or more, A circuit board characterized in that at least a portion of the metal sheet in each of the first regions has a first extension portion extending in the column direction of the pad array, and the second slits are divided by the first extension portion in each row direction of the pad array in each of the first regions, and at least a portion of the metal sheet in each of the second regions has a second extension portion extending in the row direction of the pad array, and the second slits are divided by the second extension portion in each column direction of the pad array in each of the second regions.

2. A circuit board as described in claim 1, characterized in that the first slit and / or the second slit are formed by etching the metal layer.

3. A circuit board as described in claim 1, characterized in that the pads corresponding to two adjacent metal sheets in each of the first region and the second region are arranged symmetrically.

4. A circuit board as described in claim 1, characterized in that the first slit and / or the second slit extend in a serpentine manner and form right angles or rounded corners at the corners of the extension path.

5. A circuit board as described in claim 1, characterized in that the number of second slits extending in the column direction in the first region is less than the number of second slits extending in the column direction in the second region.

6. The circuit board described in claim 1, characterized in that the metal sheet, the first region, and the second region are rectangular.

7. The circuit board described in claim 1, characterized in that the metal layer is a copper foil layer or an aluminum foil layer.

8. The circuit board described in Claim 1, characterized in that the circuit board includes at least two insulating substrates arranged in a stacked manner, each of the insulating substrates is provided with the metal layer, and the metal layers on at least some of the insulating substrates are electrically connected.

9. An electronic device that is a display panel, characterized in that it includes a circuit board as described in claim 1 and electronic components that are provided on the circuit board and soldered to the corresponding pads.

10. The electronic device described in Claim 9, characterized in that the electronic component is at least one of a resistor, a capacitor, and an LED chip.

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