Circuit board and electronic apparatus

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 mounting technology, and in particular 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, and 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 by methods such as reflow soldering or dip soldering. As electronic devices become smaller, SMT has become widely used in the manufacture of electronic devices.

[0003] The steel mesh is a special mold for surface mounting technology, which has the main function of assisting the deposition of tin paste, so as to transfer a precise amount of tin paste to the corresponding pad position on the printed circuit board. For the structure of a conventional printed circuit board, a slit is usually provided in the metal layer of the board, the metal layer is divided into a number of metal sheets insulated from each other to form corresponding wiring, and a solder resist layer (with the pad exposed in the solder resist layer) covering the pad and wiring is provided at the corresponding position on the wiring. Specifically, as shown in FIG. 1, the printed circuit board has a slit C1 extending in the horizontal direction and a slit C2 extending in the vertical direction. Here, the vertically extending slits C2 span multiple metal sheets in a vertical direction in succession, forming long vertical slits. In the process of printing solder on a printed circuit board, after the solder is applied to the steel mesh, in the process of moving the knife over the steel mesh, when passing through the vertical slits C2, the steel mesh will deform and sink 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 in 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 technology, the object of the present application is to provide a circuit board and an electronic device that can reduce the depression 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 a front surface and / or a rear surface of the substrate, the metal layer having 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 direction and the column direction of the region array and insulated from each other, Each of the first region and the second region has at least two mutually insulated metal sheets formed by dividing them 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 region and the second region, and the pads in each of the first region and the second region 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, wherein at least a portion of the metal sheet in each of the first regions has a first extension portion extending in a 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. Effect of the Invention

[0008] The circuit board provided by the present application has at least a portion of the metal sheet in each of the first regions having 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 having 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] a metal layer on a substrate is divided by a first slit into at least two first regions and second regions which are alternately arranged in row and column directions and insulated from each other to form a region array; the metal layer in each of the first and second regions is divided by a second slit into at least two metal sheets which are insulated from each other; and pads for connecting to one electronic component are provided correspondingly on two adjacent metal sheets to form wiring for a circuit board; and the formation of wiring is simple and efficient; Also, the pads in each of the first and second regions are arranged in an array of a plurality of rows and columns on the substrate to form a pad array, at least a portion of the metal sheet in each of the first regions has a first extension portion extending in a column direction of the pad array, and in each row direction of the pad array in each of the first regions, a second slit is divided by the first extension portion to form a support point for supporting 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, the second slit is divided by the first extension portion to form a support point for supporting the steel mesh in each column direction. The second slits are interrupted by the second extensions to form support points for supporting the steel mesh in both the row direction and the column direction of the pad array, thus ensuring sufficient support points in both the row direction and the column direction of the pad array, whereby the degree of deformation of the steel mesh at the position of the second slits is reduced as much as possible during solder printing, for example, the degree of dent of the steel mesh at the position of the second slits is reduced as much as possible, the service life of the steel mesh is extended, the accuracy of solder coating is improved, and the loss and cost of the steel mesh is reduced. In addition, the present application only requires sophisticated improvements in the distribution of the second slits, and does not require the addition of 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 the second slits on the circuit board can reduce the degree of deformation of the steel mesh at the position of the second slits during solder printing, thereby avoiding damage to the steel mesh caused by excessive depression at the position of the second slits as much as possible, 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 description 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 briefly introduces 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 creative labor. [Figure 1] FIG. 1 is a diagram illustrating a configuration of a conventional printed circuit board. [Diagram 2] 1 is a top view of a surface of a circuit board provided according to an embodiment of the present application. [Diagram 3] 1 is a schematic cross-sectional view of a circuit board provided according to an embodiment of the present application. [Figure 4] 2 is a schematic cross-sectional view of a circuit board provided according to an embodiment of the present application. [Diagram 5] 3 is a schematic cross-sectional view of a circuit board provided according to an embodiment of the present application. [Figure 6] 2 is a top view 2 of a surface of a circuit board provided according to an embodiment of the present application. [Figure 7] 3 is a top view of a surface of a circuit board provided according to an embodiment of the present application. [Figure 8] FIG. 2 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 PREFERRED EMBODIMENTS

[0012] In order to facilitate the understanding of the present application, the present application will now be described more fully with reference to the accompanying drawings, in which: The drawings show preferred embodiments of the present application; However, the present application is not limited to the embodiments set forth herein, but may be embodied in various forms; On the contrary, the purpose of providing these embodiments is 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 terms used in the present specification are for the purpose of describing specific embodiments only and are not intended to be limiting of the present specification.

[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 labor also belong to the protection scope of the present application.

[0015] 2 and 3 are schematic diagrams of the circuit board provided by this embodiment, in which FIG. 2 is a top view of the surface of the circuit board, and FIG. 3 is a schematic cross-sectional view including two adjacent metal sheet portions in FIG. 2. This embodiment provides a circuit board including a substrate 10 and a metal layer 20 provided on the substrate 10, and although FIGS. 2 and 3 show that a metal layer is provided on the surface of the substrate, it should be understood that the metal layer 20 may be provided on the back surface of the substrate 10, or the metal layer 20 may be provided on both the front and back surfaces of the substrate 10. For ease of understanding, the following description will be given taking the metal layer 20 provided on the front surface of the substrate 10 as an example. The substrate 10 in this embodiment is an insulating substrate, and the material of the substrate 10 may be determined according to the application scene of the circuit board. For example, when the substrate 10 needs to be folded, a flexible material such as epoxy resin may be selected, which has good heat dissipation, is thin, can be bent, folded, and rolled, and can be moved and expanded arbitrarily in three-dimensional space, so that a three-dimensional circuit board in three-dimensional space can be formed. When the substrate 10 is required to have a certain level of support for the circuit board, it can be supported by selecting a rigid material such as a ceramic substrate having a certain level of mechanical strength.

[0016] The metal layer 20 in this embodiment may be a conductive layer having electrical conductivity such as copper foil or aluminum foil, and the metal layer 20 is provided with slits 21. Here, the slits 21 include a first slit 211 that divides the metal layer 20 into at least two first regions 221 and at least two second regions 222, and the first slit 211 penetrates the front and back surfaces of the metal layer 20 (that is, the bottom of the first slit 211 is the front surface of the substrate 10, and the first slit is not specifically shown in FIG. 2, and the reference numeral 211 in FIG. 2 is an example of the position where the first slit is 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, and 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 provided with the first region 221 and the second region 222 in sequence, the second row of the region array is provided with the second region 222 and the first region 221 in sequence, the first column of the region array is provided with the first region 221 and the second region 222 in sequence, and the second column of the region array is provided with the second region 222 and the first region 221 in sequence, and the first region 221 and the second region 222 adjacent to each other are separated and insulated from each other by the first slit 21. It should be understood that the region array shown in FIG. 2 is merely an example for easy understanding, and in actual applications, it 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.

[0017] As shown in FIG. 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, and 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 shows an example of the planar structure of the second slit), and insulates the 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 they 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 positive and negative pads, respectively, and are used to connect the positive and negative leads of the same electronic component. As shown in Fig. 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 the pads 23 formed in each of the first region 221 and the second region 222 is a 12*8 array, that is, 12 rows and 8 columns. It should be understood that the pad array shown in Fig. 2 is also just an example for easy understanding, and in actual application, 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; 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 portion A2 forms a support point for supporting the steel mesh, thus ensuring that the steel mesh is supported by sufficient support points in both each row direction and each column direction of the pad array, thereby reducing the degree of deformation of the steel mesh during printing solder at the position of the second slits 212 as much as possible, extending the service life of the steel mesh, improving the accuracy of solder coating, and reducing the loss and cost of the steel mesh. In the example shown in FIG. 2, by simply adjusting the distribution of the second slits 212, no other parts or processes need to be added, which is simple to manufacture, versatile 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 thereto, 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 the two adjacent metal sheets 22 in each of the first region 221 and the second region 222 may be arranged in a plurality of rows and columns by being arranged symmetrically in the X direction. However, it should be understood that in this embodiment, the pads 23 correspondingly arranged on the two adjacent metal sheets 22 are not limited to being arranged symmetrically, and may be asymmetrical 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 sheet 22 of the second region 222 along the second extension portion 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 slit 212 extending along the column direction in the first region 221 spans 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 sheet 22 in the first region 221 along the first extension portion A1 in the column direction, so that the length D3 in the same row direction X of one second slit 212 in the same row direction X 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, 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 slit 212 in the first region 221 and the length D4 of the second slit 212 in the second region 222 are different (i.e., in each row direction, the second slit 212 in the first region 221 is divided by the metal sheet 22 in the first region 221 along the first extension portion A1 in the column direction, but the second slit 212 in the second region 222 is formed across multiple metal sheets 22) in the same row direction X, when solder is printed using the steel mesh, the support strength in the same straight line direction in the row direction of the steel mesh is increased with each first extension portion A1 as a support point, thereby reducing the depression of the steel mesh when solder is printed in both the row direction and column direction, and the service life of the steel mesh can be extended.

[0022] As can be understood, in other embodiments, the length D1 of the second slit 212 in the first region 221 may be shorter than the length D2 of the second slit 212 in the second region 222, and the length D3 of the second slit 212 in the first region 221 may be longer than the length D4 of the second slit 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 the column direction in this embodiment are two relative concepts, such that the rows in Fig. 2 become columns in Fig. 7, and the columns in Fig. 2 become 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 to 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 extension portion A2 extending in the row direction, so that the number of the second slits 212 extending in the column direction Y in the first region 221 is smaller than the number of the 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 the second slits 212 (see K1 in FIG. 2) in the first region 221 is 1, and the number of the second slits 212 (see K2, K3, and K4 in FIG. 2) in the second region 222 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 separating the pads 23 between adjacent metal sheets 22 and connecting to the trunk slits, and one 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 FIG. 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 part parallel to the trunk slit and a part perpendicular to the trunk slit, and a bending angle is formed at the connection point between the part parallel to the trunk slit and the part 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 can reduce the degree of dent of the steel mesh when printing tin paste on the circuit board and extend 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 further extending the practical life of the steel mesh.

[0027] In this embodiment, the first slit 211 is located at the edge of the single first region 221, the second slit 212 is located inside the first region 221, and the first slit 211 and the second slit 212 are 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. 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, and the first slit 211 and the second slit 212 are 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 of the pins of the electronic device to be soldered to the pads 23 on both sides 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 a desired circuit. In addition, the direction, width, etc. of the first slits 211 and the second slits 212 can be rationally designed according to the needs of the circuit, 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 slit 211 and the second slit 212 shown in Fig. 2 is the same as the row direction and column direction of the pad array, and 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 meandering manner, for example, the second slit 212 extends in a meandering manner in the row direction X and the column direction Y, and forms a right angle at the corner of the extension path (of course, rounded corners or other types of corners may be substituted). By making the second slit 212 meander in the row direction X and the column direction Y so that the multiple metal sheets 22 or a combination of the multiple metal sheets 22 form a rectangle, the layout design of the electronic component at the time of packaging is facilitated.

[0030] As can be appreciated, in other embodiments, the second slits 212 may extend in other serpentine directions to divide the metal layer 20 into metal sheets of other shapes, such as circles, trapezoids, diamonds, triangles, 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 to surround the multiple metal sheets 22 with rectangular first and second regions 221 and 222, which facilitates the layout design of the electronic components during packaging. As can be understood, in other embodiments, the first slits 211 may extend in other directions following the extension path of the second slits 212 to form the first and second regions 221 and 222 of any shape, such as a circle, a trapezoid, a rhombus, a triangle, etc., together with the second slits 212.

[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 the direction perpendicular to the substrate 10. The solder resist layer 30 has the role of insulation and solder resist. For example, in this embodiment, the material of the solder resist layer 30 is solder resist ink, but in other embodiments, the solder resist layer 30 may be made of solder resist, solder resist, etc. In addition, in the circuit board mounting process, the pads 23 for fixing electronic components to the pads 23 need to be tin-plated, and the interval between adjacent pads 23 is narrow, so that the slits 21 are filled with the solder resist layer 30 that isolates different metal sheets 22, thereby preventing mutual influence between electronic components due to solder bridges between adjacent pads 23. In addition, the solder resist layer 30 also has the role of preventing solder from overflowing and preventing short circuits in 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 only falls on 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, both the front and back surfaces of the substrate may be provided with metal layers, 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 them 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 the first surface 11, and the back surface of the substrate 10 is the second surface 12, and it should be understood that the front surface and the back surface of the substrate 10 are relative to each other. The first surface 11 is provided with a first metal layer 201, the second surface 12 is provided with a second metal layer 202, and the first surface 11 and the second surface 12 on the opposite side of the substrate 10 are provided with circuits and electronic components are mounted, 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, when 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 the dents of the steel mesh on both the front and back sides of the circuit board when solder is printed on the circuit board can be achieved. As can be understood, the structure of at least one of the first metal layer 201 and the second metal layer 202 being the same as the structure of the metal layer 20 may specifically include that 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, or that 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 that both the structures of 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 embodiment, 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 necessary. For example, referring to the example of FIG. 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 there are various methods for connecting 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 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 the conductive material may contact the first metal layer 201 and the second metal layer 202 at the same time to realize the conductive action. Here, the conductive material includes 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, save space, etc.

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

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

[0036] For ease of understanding, in this example, as shown in FIG. 5 (a schematic cross-sectional view including two adjacent metal sheet portions as shown in FIG. 5), two substrates 10, here called the first substrate 101 and the second substrate 102, are bonded by an adhesive layer 40, and a multilayer circuit board structure will be described for ease of understanding. The first substrate 101 is provided with a first metal layer 201 and a pad 23 to form a first sub-circuit board, and the second substrate 102 is provided with a second metal layer 202 and a pad 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 the surfaces of the two substrates 10 that are 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 the demand for multi-functionality of electronic devices is high, a large number of wiring layers are 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 wirings in the multi-layer wiring structure can be avoided, and by applying the circuit board provided by the present application to a multi-layer circuit board, it can contribute to reducing the manufacturing cost 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] The embodiment of the present application provides an electronic device including an electronic component and the circuit board described above, and the electronic component is provided on the circuit board and soldered to the corresponding pad. For example, the electronic component may be directly soldered to the pad 23. The electronic component in this embodiment is at least one of a capacitor, a resistor, and an LED chip, and may be an electronic component having a positive electrode lead and a negative electrode lead. The positive electrode lead and the negative electrode lead may be fixed to the pad 23 by printing a tin paste on the pad 23 using a steel mesh and then soldering the tin paste (which may be replaced with fixing by a conductive adhesive). By using the circuit board provided by the embodiment of the present application, the distribution of the second slits on the circuit board can reduce the degree of deformation of the steel mesh at the position of the second slit during solder printing, so that the damage of the steel mesh due to the excessive degree of depression at the position of the second slit can be avoided as much as possible, and the accuracy of the solder printed using the steel mesh can be guaranteed, thereby improving the reliability and yield of the circuit board and the 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 scene, an LED chip can be soldered to each pad in each first region and second region on the circuit board, and all the 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 the LED chips in each second region are combined into one large LED chip array on the board. In the following, for ease of understanding, an example of soldering an LED chip L to the circuit board shown in FIG. 2 will be described, but 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. Here, as shown in Fig. 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 of 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 of the series circuit, see the dashed line indicated by I2 in Fig. 8.

[0040] 2, at least two first regions 221 and 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 individually controlled as a whole, that is, the brightness of the LED chips in a certain region can be individually controlled to adjust the brightness of a certain sub-region of the display panel, 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 can understand that equivalent modifications to the scope of the present application fall within the scope of the present application.

Claims

1. A circuit board comprising at least one substrate and a metal layer disposed on a front surface and / or a rear surface of the substrate, the metal layer having 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 direction and the column direction of the region array and insulated from each other; Each of the first region and the second region has at least two mutually insulated metal sheets formed by dividing them 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 region and the second region, and the pads in each of the first region and the second region are arranged in an array of a plurality of rows and columns on the substrate to form a pad array; 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 a column direction of the pad array, and the second slit is 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 slit is divided by the second extension portion in each column direction of the pad array in each of the second regions.

2. 2. The circuit board according to claim 1, wherein the extending direction of the first slits and / or the second slits is the same as the row direction and column direction of the pad array.

3. The circuit board according to claim 1 , wherein a width of the first slit is smaller than a width of the second slit.

4. 2. The circuit board of claim 1, wherein the number of pads in the first area and the number of pads in the second area are equal.

5. The circuit board according to claim 1 , wherein the first slit and / or the second slit extends in a serpentine manner.

6. 2. The circuit board according to claim 1, wherein the first slit and the second slit are filled with a solder resist layer, and a height of the solder resist layer in a direction perpendicular to the substrate is lower than a height of the metal sheet.

7. 2. The circuit board according to claim 1, wherein the metal layer is provided on both the front and back surfaces of the board.

8. 8. The circuit board according to claim 7, further comprising a via penetrating the substrate from its front surface to its rear surface, electrically connecting the metal layers on the front surface and the rear surface.

9. 2. The circuit board according to claim 1, comprising at least two substrates arranged in a stacked manner, each of the substrates being provided with the metal layer.

10. 10. The circuit board according to claim 9, wherein the circuit board includes two of the substrates and an adhesive layer that bonds the two substrates to each other, and the metal layer is provided on both sides of the two substrates away from the adhesive layer.

11. 11. The circuit board of claim 10, further comprising vias penetrating the two substrates and the adhesive layer, the metal layers on the two substrates being electrically connected through the vias.

12. 2. The circuit board according to claim 1, further comprising a support region between the first region and the second region adjacent to each other.

13. 2. The circuit board of claim 1, wherein the second slits in the first and second regions include trunk slits extending in a row or column direction of the pad array and branch slits separating the pads between adjacent metal sheets and connected to the trunk slits, wherein one trunk slit is connected to each of a plurality of branch slits, and the trunk slits in the first region are perpendicular to the extension direction of the trunk slits in the second region.

14. 2. An electronic device comprising: the circuit board according to claim 1; and an electronic component provided on the circuit board and soldered to the corresponding pad.

15. The electronic device according to claim 14 , wherein the electronic component includes an LED chip.

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