Substrate, backlight plate, display device and electronic device

Abstract

The present disclosure relates to the technical field of display. Provided are a substrate, a backlight plate, a display device and an electronic device. A bonding pad and a solder mask layer are provided on a surface of the substrate; the bonding pad comprises a first region and a second region, the first region having a first edge and a second edge, the first edge being opposite the second edge in a first direction, at least part of the second region being located on the side of the first edge away from the second edge; and part of the solder mask layer is located on the side of the first edge away from the first region. A lamp bead is less prone to deviating from a preset position, thereby improving the positional accuracy of the lamp bead.

Description

Substrates, backlights, display devices, and electronic devices

[0001] Cross-references to related applications

[0002] This disclosure claims priority to Chinese Patent Application No. 202410832304.8, filed on June 25, 2024, entitled "Substrate, Backlight Panel, Display Device and Electronic Device", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to the field of display technology, and more particularly to a substrate, a backlight panel, a display device, and an electronic device. Background Technology

[0004] Liquid crystal display devices include a backlight panel, on which LED chips are soldered. In the prior art, the LED chips in the backlight panel are prone to tilting, misalignment, and other phenomena. Summary of the Invention

[0005] Embodiments of this disclosure provide a substrate, a backlight panel, a display device, and an electronic device.

[0006] The embodiments of this disclosure adopt the following technical solutions:

[0007] On one hand, a substrate is provided, the surface of which is provided with pads and a solder resist layer. The pads include a first region and a second region. The first region has a first edge and a second edge. The first edge and the second edge are opposite to each other along a first direction. At least a portion of the second region is located on the side of the first edge away from the second edge. A portion of the solder resist layer is located on the side of the first edge away from the first region.

[0008] In some implementations, the first region and the second region are connected as a single structure.

[0009] In some embodiments, the first edge includes a first end and a second end opposite to each other, and the second region includes a first sub-region and a second sub-region, the first sub-region being located at the first end and the second sub-region being located at the second end.

[0010] In some implementations, the first sub-region and the second sub-region are disconnected on the side away from the first region.

[0011] In some implementations, the first sub-region and the second sub-region are connected on the side away from the first region.

[0012] In some embodiments, the first edge includes multiple sub-edges spaced apart along a second direction; the second direction is perpendicular to the first direction.

[0013] In some embodiments, the pad further includes a connection region located between the second region and the first region, the connection region being a connection region between two adjacent sub-edges, through which the second region is connected to the first region.

[0014] In some implementations, the first region is disconnected from the second region.

[0015] In some implementations, the length of the first edge is less than or equal to the length of the second edge.

[0016] In some embodiments, the dimensions of the first region and the second region along the second direction are widths, and the width of the second region is greater than the width of the first region; the second direction is perpendicular to the first direction.

[0017] In some implementations, the width of the pad region gradually increases along the direction toward the second region.

[0018] In some embodiments, a solder resist layer is provided around the pad, and the solder resist layer is disposed in the same layer as the pad.

[0019] In some embodiments, the pads include a first pad and a second pad, the first pad and the second pad being arranged at intervals along the first direction, and the first areas of the first pad and the second pad being disposed opposite to each other.

[0020] On the other hand, a backlight panel is provided, comprising a substrate, solder, and LED chips. The surface of the substrate is provided with pads and a solder resist layer. The pads include a first region and a second region. The first region has a first edge and a second edge, the first edge and the second edge being opposite each other along a first direction. At least a portion of the second region is located on the side of the first edge away from the second edge, and a portion of the solder resist layer is located on the side of the first edge away from the first region. The solder is located on the surfaces of the first region and the second region. The LED chips are provided with pins, the pins being connected to the solder within the first region, and the pins being located between the first edge and the second edge.

[0021] In another aspect, an electronic device is provided, comprising a substrate, solder, and electronic components. The surface of the substrate is provided with pads and a solder resist layer. The pads include a first region and a second region. The first region has a first edge and a second edge, the first edge and the second edge being opposite each other along a first direction. At least a portion of the second region is located on the side of the first edge away from the second edge, and a portion of the solder resist layer is located on the side of the first edge away from the first region. The solder is located on the surfaces of the first region and the second region. The electronic components are provided with pins, the pins being connected to the solder within the first region, and the pins being located between the first edge and the second edge.

[0022] The substrate, backlight panel, and electronic device provided in this disclosure embodiment, during the soldering process between the pins and pads, the liquid solder is confined to the area within the surface of the pad, that is, the liquid solder is confined to the area enclosed by the edge of the pad. When the pin is placed on the pad, since the pin can only float within the area where the liquid solder is located, that is, the pin can only be within the area enclosed by the edge of the pad. The pin is placed in the soldering area, that is, the pin is located between the first edge and the second edge. The pin is confined between the first edge and the second edge, and cannot cross the first edge into the second area, reducing the floating range of the pin, thereby making it less likely for the LED to deviate from the preset position and improving the positional accuracy of the LED. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 is a front view of a display device provided in an embodiment of this disclosure;

[0025] Figure 2 is a simplified cross-sectional structure diagram of a display module provided in an embodiment of this disclosure;

[0026] Figure 3 is a simplified cross-sectional diagram of a type of LED bead;

[0027] Figure 4 illustrates a simplified process for pre-applying solder paste;

[0028] Figure 5 shows a simplified diagram of the substrate after pre-coating with solder paste;

[0029] Figure 6 shows a simplified diagram of the substrate after the LED chips are attached;

[0030] Figure 7 shows a simplified diagram of the LED chip after it has been soldered to the substrate.

[0031] Figure 8 is a simplified diagram of the LED chip and substrate being tilted after welding in the related technology;

[0032] Figure 9 is a schematic diagram of the lamp bead and the substrate after welding in the related technology;

[0033] Figure 10 is another schematic diagram of the lamp bead and substrate after welding in the related technology;

[0034] Figure 11 is a partial structural schematic diagram of a substrate provided in an embodiment of this disclosure;

[0035] Figure 12 is a cross-sectional view of BB in Figure 11;

[0036] Figure 13 is a schematic diagram of a solder pad in an embodiment of this disclosure;

[0037] Figure 14 is a schematic diagram showing the relative positions of the pins and pads in an embodiment of this disclosure;

[0038] Figure 15 is a cross-sectional view of CC in Figure 14;

[0039] Figure 16 is a schematic diagram of the lamp beads and solder pads after being soldered in an embodiment of this disclosure;

[0040] Figure 17 is a schematic diagram of another type of pad in an embodiment of this disclosure;

[0041] Figure 18 is a schematic diagram of another type of pad in an embodiment of this disclosure;

[0042] Figure 19 is a schematic diagram of another type of pad in an embodiment of this disclosure;

[0043] Figure 20 is a schematic diagram of another type of pad in an embodiment of this disclosure. Specific Implementation

[0044] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this disclosure.

[0045] In the embodiments of this disclosure, the use of terms such as "first," "second," "third," and "fourth" to distinguish identical or similar items with essentially the same function and effect is only for the purpose of clearly describing the technical solutions of the embodiments of this disclosure, and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated.

[0046] In embodiments of this disclosure, "a plurality of" means two or more, and "at least one" means one or more, unless otherwise expressly and specifically defined.

[0047] In the embodiments of this disclosure, the terms "upper" and "lower" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this disclosure and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this disclosure.

[0048] Figure 1 is a front view of a display device provided in an embodiment of this disclosure. As shown in Figure 1, some embodiments of this disclosure provide a display device 1000, which can be any device with display functionality. For example, the display device 1000 can be a mobile phone, wireless device, personal data assistant (PDA), handheld or portable computer, GPS receiver / navigator, camera, MP4 video player, camcorder, game console, watch, clock, calculator, television monitor, flat panel display, computer monitor, automotive display (e.g., odometer display, etc.), navigator, cockpit controller and / or display, camera view display (e.g., display of a rearview camera in a vehicle), electronic photograph, electronic billboard or sign, projector, architectural structure, packaging and aesthetic structure (e.g., display of an image of a piece of jewelry), etc. Figure 1 illustrates the display device 1000 as a computer monitor.

[0049] The display device 1000 includes a display module 100, which displays images. Figure 2 is a simplified cross-sectional view of a display module according to an embodiment of the present disclosure. As shown in Figure 2, the display module 100 includes a display panel 110 and a backlight panel 120. The display panel 110 can be a liquid crystal display (LCD), and the backlight panel 120 provides backlighting for the display panel 110.

[0050] When the display panel 110 is a liquid crystal display panel, it can be either a horizontal electric field type liquid crystal display panel or a vertical electric field type liquid crystal display panel. When the display panel 110 is a horizontal electric field type liquid crystal display panel, the display panel 100 can be an in-plane switching (IPS) liquid crystal display panel or an advanced super-dimensional switching (ADS) liquid crystal display panel.

[0051] Referring again to FIG2, the backlight panel 120 includes a substrate 121 and a plurality of LEDs 122 disposed on the substrate 121. For example, the backlight panel 120 includes a plurality of LEDs 122 disposed on the surface of the substrate 121 facing the display panel 110, and the plurality of LEDs 122 are arranged in an array.

[0052] The LED chip 122 can be a light-emitting diode (LED) or a sub-millimeter light-emitting diode (Mini LED). The following description will only use Mini LED as an example.

[0053] Figure 3 is a simplified cross-sectional view of an LED chip 122. As shown in Figure 3, the LED chip 122 includes pins 10, which are electrically connected to a driving circuit. For example, the LED chip 122 includes an anode pin 10 and a cathode pin 10, which are electrically connected to the driving circuit respectively. The driving current flows from the anode pin 10 to the cathode pin 10, thereby causing the LED chip 122 to emit light under the drive of the driving current.

[0054] The substrate 121 has pads 23 on its surface, and the leads 10 of the lamp bead 122 are soldered to the pads 23, thereby fixing the lamp bead 122 and electrically connecting the lamp bead 122 to the driving circuit. That is, the end of the lamp bead 122 with the leads 10 faces the surface of the substrate 121.

[0055] The following describes the process of soldering LED chip 122 onto the surface of substrate 121 using reflow soldering as an example. The reflow soldering process may include multiple steps such as pre-applying solder paste, chip mounting, and reflow soldering.

[0056] Figure 4 illustrates a simplified process for pre-applying solder paste, and Figure 5 illustrates a simplified diagram of the substrate 121 after pre-applying solder paste. Exemplarily, as shown in Figures 4 and 5, the surface of the substrate 121 with pads 23 is the soldering surface. During the pre-applying solder paste process, a template (e.g., a stencil) is placed above the soldering surface. An opening is provided in the area of ​​the template directly opposite the pads 23. Solder paste is pre-applied to the surface of the template away from the substrate 121. A scraper moves from left to right as shown in the figure. Under the action of the scraper, the solder paste adheres to the surface of the pads 23 through the opening, thus obtaining the substrate 121 with solder paste adhered as shown in Figure 5.

[0057] Figure 6 shows a simplified diagram of the LED chip 122 after it has been attached to the substrate 121. As shown in Figure 6, during the mounting process, the end of the LED chip 122 with the lead 10 is oriented toward the soldering surface of the substrate 121, and the lead 10 of the LED chip 122 is brought into contact with the solder paste.

[0058] Figure 7 shows a simplified diagram of the LED 122 after being soldered to the substrate 121. As shown in Figure 7, during the reflow soldering process, the solder in the solder paste melts under high temperature and flows evenly to cover the surface of the pad 23. After the solder cools, it solidifies to fix the solder to the pin 10 and the pad 23 and to achieve electrical connection.

[0059] However, in practical applications, it has been found that after the LED chip 122 is soldered to the substrate 121, the LED chip 122 is prone to tilting at a certain angle relative to the substrate 121. Figure 8 is a simplified diagram of the tilted state of the LED chip 122 after soldering to the substrate 121 in related technologies. For example, Figure 8 is a view from direction A in Figure 7. As shown in Figure 8, when the volume of solder is large, after the solder melts, the thickness of the liquid solder along the vertical direction shown in the figure is relatively thick. The LED chip 122 floats on the liquid solder, which easily causes the LED chip 122 to tilt. After the liquid solder solidifies, the LED chip 122 tilts at a certain angle relative to the substrate 121.

[0060] To prevent the LED chip 122 from tilting relative to the substrate 121 after soldering, one proposed method is to reduce the volume of solder paste pre-coated on the pad 23. With a fixed area of ​​the pad 23, reducing the volume of solder paste reduces the volume of solder within it, thereby reducing the size of the liquid solder along the vertical direction shown in Figure 7. For example, reducing the size of the opening in the stencil reduces the volume of solder paste that passes through the opening. However, the size of the opening in the stencil needs to meet certain requirements. If the opening size is too small, the solder paste will not easily adhere to the surface of the pad 23, preventing the LED chip 122 from being soldered to the pad 23.

[0061] For example, continuing to refer to Figure 4, the width of the opening is w, the thickness of the opening is t, the ratio of the width to the thickness of the opening (w / t) needs to be greater than 1.5, and the ratio of the area of ​​the opening to the area of ​​the sidewall of the opening needs to be greater than 0.66. When the size of the opening cannot meet the above requirements, solder paste will not easily adhere to the surface of the pad 23 through the opening. In practical applications, the area of ​​the opening needs to be compatible with the area of ​​the pad 23. For example, the area of ​​the opening needs to be smaller than the area of ​​the pad 23 to avoid solder paste being pre-applied outside the area of ​​the pad 23 as much as possible and to reduce the volume of solder paste. When the LED 122 is a Mini LED 122, due to the small size of the LED 122 (e.g., 50μm to 200μm), the pin 10 of the LED 122 is also small (e.g., 25μm to 100μm), and correspondingly, the area of ​​the pad 23 is also small. However, in order to meet the requirements of the ratio of the width to the thickness of the opening and the ratio of the area of ​​the opening to the area of ​​the sidewall of the opening, the opening size cannot be further reduced.

[0062] To prevent the LED chip 122 from tilting relative to the substrate 121 after soldering, another method proposed in related technologies is to increase the area of ​​the pad 23. With a fixed solder volume, increasing the area of ​​the pad 23 can reduce the thickness of the solder along the vertical direction shown in Figure 7. However, increasing the area of ​​the pad 23 results in poorer positional accuracy of the LED chip 122 during soldering.

[0063] Specifically, the solder melts to form liquid solder and covers the surface of the welding machine. Due to the good fluidity of the liquid solder, the LED 122 can move within the area covered by the liquid solder along a direction parallel to the substrate 121. Increasing the area of ​​the pad 23 increases the range of movement of the LED 122 on the pad 23, making it easier for the LED 122 to deviate from its preset position. This reduces the light emission uniformity of the backlight panel 120 and may even cause some LEDs 122 to fail to emit light normally. Figure 9 is a schematic diagram of one type of LED 122 after welding to the substrate 121 in the related art, and Figure 10 is another schematic diagram of another type of LED 122 after welding to the substrate 121 in the related art. As shown in Figure 9, the LED 122 deviates from the center of the pad 23 along the left-right direction shown in the figure and is welded to a position slightly to the right of the pad 23, reducing the light emission uniformity of the backlight panel 120. As shown in Figure 10, the LED 122 is only welded to one pad 23 and not to the other, causing this LED 122 to fail to emit light.

[0064] Therefore, the substrate 121 provided in this embodiment employs a novel pad 23, which improves the tilt of the LED bead 122 relative to the substrate 121 while preventing the LED bead 122 from easily deviating from its predetermined position. The substrate 121 provided in this embodiment will now be described in detail with reference to the accompanying drawings.

[0065] Figure 11 is a partial structural schematic diagram of a substrate 121 provided in an embodiment of this disclosure, and Figure 12 is a cross-sectional view of BB in Figure 11. As shown in Figures 11 and 12, the surface of the substrate 121 is provided with pads 23, and the surface of the pads 23 can be exposed to facilitate the soldering of the pads 23 to the LED beads 122.

[0066] Referring again to FIG12, the substrate 121 may further include a substrate 21 and a conductive line 22. The conductive line 22 is disposed on the surface of the substrate 21, and the pad 23 is located on the side of the conductive line 22 away from the substrate 21, and the pad 23 is electrically connected to the conductive line 22.

[0067] The substrate 21 can be a glass substrate 21. In this case, a glass-based semiconductor process can be used to fabricate the substrate 121, for example, to fabricate the conductive lines 22 and the pads 23. Of course, the substrate 21 can also be made of other materials; this embodiment does not limit the material of the substrate 21.

[0068] The material of the conductive line 22 can be a metal, such as copper. For example, a copper conductive layer is formed on the surface of the substrate 21, and then the conductive line 22 is formed in the copper conductive layer by a patterning process.

[0069] The pad 23 is formed on the side of the conductive line 22 away from the substrate 21. For example, the pad 23 is electroless nickel / impression gold (ENIG), also known as immersion nickel gold, electroless nickel gold, or electroless nickel gold. It is formed by chemically replacing palladium on the surface of the conductive line 22, then chemically plating a nickel-phosphorus alloy layer on the palladium core, and then plating a layer of gold on the nickel surface through a substitution reaction. When the pad 23 is electroless nickel gold, the soldering performance of the pad 23 is better. Of course, the embodiments of this disclosure do not limit the material and manufacturing process of the pad 23.

[0070] Referring again to Figures 11 and 12, the substrate 121 may further include a solder resist layer 24, which is located around and surrounds the pad 23. The solder resist layer 24 does not easily adhere to the solder, thereby confining the solder as much as possible to the area where the pad 23 is located.

[0071] For example, the solder mask layer 24 is disposed on the same layer as the pad 23. For instance, along the thickness direction of the pad 23, the surface of the solder mask layer 24 away from the substrate 21 is flush with the surface of the pad 23 away from the substrate 21.

[0072] For example, the main material of the solder mask layer 24 is an acrylic copolymer.

[0073] It should be noted that the embodiments disclosed herein only use the structure of substrate 121 including glass substrate 21 as an example. In actual applications, substrate 121 can also be a printed circuit board (PCB), with pads 23 located on the surface of the PCB. The PCB also has a conductive layer inside, with conductive lines 22 inside the conductive layer, and the conductive lines 22 are electrically connected to the pads 23. In this case, the pads 23 can be electroless nickel-gold, or they can be metals such as copper or aluminum.

[0074] Figure 13 is a schematic diagram of a solder pad 23 according to an embodiment of this disclosure. The area within the dashed frame in Figure 13 is the first region 231, and the area outside the dashed frame is the second region 232. As shown in Figure 13, the solder pad 23 includes the first region 231 and the second region 232. After the solder pad 23 is soldered to the LED bead 122, the surfaces of both the first region 231 and the second region 232 are covered with solder, and the leads 10 of the LED bead 122 are soldered to the first region 231.

[0075] In addition to the first region 231, the pad 23 also has a second region 232, which increases the area of ​​the pad 23. With a fixed volume of solder, increasing the area of ​​the pad 23 reduces the thickness of the solder after melting, making it less likely for the LED 122 to tilt on the liquid solder, thus improving the problem of the LED 122 tilting relative to the substrate 121 after soldering.

[0076] The sum of the areas of the first region 231 and the second region 232 can be calculated based on the volume of the solder paste and the desired thickness of the liquid solder. For example, if the volume of the solder paste is V, the desired thickness of the liquid solder is t1, and the volume ratio of the solder in the solder paste is 50%, then the sum of the areas of the first region 231 and the second region 232 is 50%*V / t1.

[0077] Referring again to Figure 13, the first region 231 has a first edge 1 and a second edge 2, which are opposite each other along a first direction X. At least a portion of the second region 232 is located on the side of the first edge 1 away from the second edge 2. That is, along the first direction X, the first edge 1 is located between the first region 231 and the second region 232.

[0078] Here, the first edge 1 and the second edge 2 are both physical edges of the pad 23, rather than virtual edges defined on the pad 23. For example, the first edge 1 and the second edge 2 are the sides of the electroless nickel-gold alloy.

[0079] A portion of the solder mask 24 is located on the side of the first edge 1 away from the first region 23, and a portion of the solder mask 23 is located on the side of the second edge 2 away from the first region 231. Of course, the pad 23 also includes other edges, and the side of each edge away from the pad 23 may also have a solder mask 24. For example, the solder mask 24 may be in close contact with the first edge 1, the second edge 2, and other edges of the pad, thus confining the liquid solder within the respective edge ranges of the pad 23.

[0080] Because the solder mask layer 24 is provided around the pad 23, the liquid solder is confined to the area on the surface of the pad 23 during the soldering process, that is, the liquid solder is confined to the area enclosed by the edge of the pad 23. When the pin 10 is placed on the pad 23, the pin 10 can only float within the area of ​​the liquid solder, that is, the pin 10 can only be within the area enclosed by the edge of the pad 23.

[0081] Figure 14 is a schematic diagram showing the relative positions of pin 10 and pad 23 in an embodiment of this disclosure. As shown in Figure 14, pin 10 of LED 122 is placed in the soldering area, that is, pin 10 of LED 122 is located between the first edge 1 and the second edge 2. As can be seen from the above, pin 10 of LED 122 is confined between the first edge 1 and the second edge 2, and cannot cross the first edge 1 into the second region 232, reducing the floating range of pin 10, thereby making it less likely for LED 122 to deviate from the preset position and improving the positional accuracy of LED 122.

[0082] Figure 15 is a cross-sectional view of CC in Figure 14. As shown in Figures 14 and 15, when pin 10 moves along the first direction X toward the second region 232 and crosses the first edge 1, pin 10 will move along the direction of the arrow shown in Figure 15 under the action of the surface tension of the liquid solder, and will eventually be confined between the first edge 1 and the second edge 2.

[0083] In practical applications, the distance between the first edge 1 and the second edge 2 can be determined based on the dimension of the pin 10 along the first direction X and the positional accuracy of the pin 10 soldering. For example, when the positional accuracy requirement of the pin 10 along the first direction X is ±30μm, the dimension of the pin 10 along the first direction X plus 60μm equals the distance between the first edge 1 and the second edge 2.

[0084] Referring again to Figure 11, the surface of the substrate 121 may be provided with a plurality of pads 23. Exemplarily, two adjacent pads 23 constitute a group of pads 23, and a group of pads 23 is used to solder to one LED chip 122. The surface of the substrate 121 is provided with a plurality of groups of pads 23. Each group of pads 23 includes a first pad 23 and a second pad 23. The first pad 23 is soldered to the anode pin 10 of the LED chip 122, and the second pad 23 is soldered to the cathode pin 10 of the LED chip 122.

[0085] Referring again to Figure 11, the first pad 23 and the second pad 23 are arranged at intervals along the first direction X, and the first regions 231 of the first pad 23 and the second pad 23 are arranged opposite to each other.

[0086] Figure 16 is a schematic diagram of the LED 122 after being soldered to the pad 23 in an embodiment of this disclosure. As shown in Figure 16, one pin 10 of the LED 122 is defined within the soldering area of ​​the first pad 23, and the other pin 10 of the LED 122 is defined within the soldering area of ​​the second pad 23. The soldering areas of the first pad 23 and the soldering areas of the second pad 23 cooperate to define the position of the LED 122.

[0087] When the LED chip 122 moves toward the first pad 23, the first edge 1 and the second edge 2 of the first pad 23 exert a pulling effect on the pin 10 located on the first pad 23, and the first edge 1 and the second edge 2 of the second pad 23 exert a pulling effect on the pin 10 located on the second pad 23, preventing the LED chip 122 from moving toward the first pad 23 and thus preventing the LED chip 122 from losing contact with the second pad 23. Similarly, when the LED chip 122 moves toward the second pad 23, the first edge 1 and the second edge 2 of the first pad 23 exert a pulling effect on the pin 10 located on the first pad 23, and the first edge 1 and the second edge 2 of the second pad 23 exert a pulling effect on the pin 10 located on the second pad 23, preventing the LED chip 122 from moving toward the second pad 23 and thus preventing the LED chip 122 from losing contact with the first pad 23.

[0088] Compared with the pad 23 shown in Figure 10, both the first pad 23 and the second pad 23 are provided with a first edge 1. When the lamp bead 122 moves along the first direction X, the first edge 1 of the first pad 23 and the first edge 1 of the second pad 23 can both exert a pulling effect on the pin 10, which increases the limiting effect on the position of the pin 10, making it less likely for the lamp bead 122 to deviate to one side of the first pad 23 or the second pad 23.

[0089] Referring again to Figure 13, in some embodiments, the first region 231 and the second region 232 are connected as a single structure, that is, the first region 231 and the second region 232 are connected, so that there is a channel for the flow of liquid solder between the first region 231 and the second region 232. The liquid solder can flow from the first region 231 to the second region 232, thereby reducing the thickness of the liquid solder in the first region 231 and preventing the lamp bead 122 from tilting.

[0090] The thicknesses of the first region 231 and the second region 232 can be the same or different. When the thicknesses of the first region 231 and the second region 232 are the same, the first region 231 and the second region 232 can be prepared in the same process, reducing the difficulty of preparing the pad 23. When the thickness of the first region 231 is greater than the thickness of the second region 232, the liquid solder can flow more easily from the first region 231 to the second region 232, thereby reducing the thickness of the liquid solder in the first region 231.

[0091] Referring again to FIG13, in some embodiments, the first edge 1 includes a first end 11 and a second end 12 opposite to each other. For example, in FIG13, the left end of the first edge 1 is the first end 11, and the right end of the first edge 1 is the second end 12.

[0092] Part of the second region 232 is located at the first end 11, and part of the second region 232 is located at the second end 12. That is, the first edge 1 divides the second region 232 into two parts, one part of which is located to the left of the first edge 1 as shown in Figure 13, and the other part is located to the right of the first edge 1 as shown in Figure 13. These two parts of the second region 232 can be connected or disconnected from each other.

[0093] Along the second direction Y, the first edge 1 is located in the region near the center of the second region 232, making it difficult for the pin 10 to cross the first edge 1 into the second region 232, thus making the first edge 1 better limit the pin 10.

[0094] For example, there is a channel for the flow of liquid solder between the first region 231 and the second region 232, and along the second direction Y, the first edge 1 is located in the region near the center of this channel.

[0095] Referring again to FIG13, in some embodiments, the second region 232 includes a first sub-region 232a and a second sub-region 232b, wherein the first sub-region 232a is located at the first end 11 and the second sub-region 232b is located at the second end 12. For example, the first sub-region 232a may be connected to the left end of the first region 231, and the second sub-region 232b may be connected to the right end of the first region 231. Liquid solder in the first region 231 may flow into the first sub-region 232a from the left end, and liquid solder in the first region 231 may flow into the second sub-region 232b from the right end.

[0096] The first sub-region 232a and the second sub-region 232b are disconnected on the side away from the first region 231. This simplifies the shape of the pad 23, making its fabrication easier. Furthermore, the first region 231 has flow channels between itself and both the first sub-region 232a and the second sub-region 232b, increasing the number of flow channels between them and allowing liquid solder to flow more rapidly from the first region 231 to the second region 232.

[0097] For example, the shape and area of ​​the first sub-region 232a can be equal to the shape and area of ​​the second sub-region 232b. That is, the pads 23 are symmetrically arranged along the center line of the first direction X.

[0098] Referring again to FIG13, in some embodiments, the length of the first edge 1 is less than or equal to the length of the second edge 2. Since the second region 232 is located on the side of the first edge 1 away from the first region 231, and the length of the first edge 1 is less than the length of the second edge 2, a channel for the flow of liquid solder can be formed between the first region 231 and the second region 232.

[0099] Referring again to Figure 13, in some embodiments, the dimensions of the first region 231 and the second region 232 along the second direction Y are the widths, the width of the first region 231 is w1, the width of the second region 232 is w2, and the width of the second region 232 is greater than the width of the first region 231, i.e., w1 < w2.

[0100] For example, the first region 231 has a third edge 3 and a fourth edge 4, which are arranged relative to each other along the second direction Y. The third edge 3 may be recessed inwards by a certain distance relative to the edge of the second region 232, or the fourth edge 4 may be recessed inwards by a certain distance relative to the edge of the second region 232, or both the third edge 3 and the fourth edge 4 may be recessed inwards by a certain distance relative to the edge of the second region 232.

[0101] During the soldering process, when pin 10 is placed in the first region 231, pin 10 is located between the third edge 3 and the fourth edge 4. Since the distance between the third edge 3 and the fourth edge 4 is smaller than the width of the second region 232, the range of motion of pin 10 is reduced while increasing the area of ​​the solder pad 23, thereby making the positional accuracy of pin 10 higher.

[0102] Referring again to Figure 13, when the third edge 3 is recessed by a certain distance relative to the edge of the second region 232, the left side of the third edge 3 is a blank area. Instead of solder pads 23, the blank area is filled with a solder resist layer 24. During pre-applied solder paste, due to limitations in the pre-applied solder paste process precision, some solder paste may be applied to the blank area. When the solder paste in the blank area melts, the solder in this portion of the solder paste is not easily adsorbed onto the solder pads 23, but instead forms solder balls under the surface tension of the liquid solder.

[0103] Similarly, when the fourth edge 4 is recessed by a certain distance relative to the edge of the second region 232, the left side region of the fourth edge 4 is a blank region. Instead of solder pads 23, the blank region is filled with a solder resist layer 24. During pre-applied solder paste, due to limitations in the pre-applied solder paste process precision, some solder paste may be applied to the blank region. When the solder paste in the blank region melts, the solder in this portion of the solder paste is not easily adsorbed onto the solder pads 23, but instead forms solder balls under the surface tension of the liquid solder.

[0104] Figure 16 is a schematic diagram of another type of pad 23 in an embodiment of this disclosure. As shown in Figure 16, the width of the pad 23 region can gradually increase along the direction toward the second region 232. This can reduce the area of ​​the blank regions on both sides of the first region 231. When some solder paste is applied to the blank regions, the solder in the solder paste in the blank regions is more easily adsorbed onto the pad 23, thereby improving the solder ball problem.

[0105] For example, the third edge 3 and / or the fourth edge 4 are inclined at a certain angle relative to the second edge 2. For example, the first region 231 is inverted trapezoidal.

[0106] It should be noted that Figure 16 shows both the third edge 3 and the fourth edge 4 as slanted straight edges. In practical applications, the shapes of the third edge 3 and the fourth edge 4 are not limited to this; they can also be curved edges, zigzag edges, or other irregular edges. For example, the third edge 3 and / or the fourth edge 4 may have sharp corners protruding towards the blank area. Liquid solder in the blank area is more easily adsorbed onto the surface of the pad 23 through the sharp corners, making it less likely for solder balls to form on the substrate 121.

[0107] Figure 17 is a schematic diagram of another type of pad 23 in an embodiment of this disclosure. As shown in Figure 17, in some embodiments, the pad 23 is provided with a cutout area 233, which is located within the area enclosed by the edge of the second area 232, and the edge of the cutout area 233 facing the first area 231 is the first edge 1.

[0108] Compared to the pads 23 shown in Figures 13 and 16, forming the first edge 1 through the cutout area 233 allows for a larger area of ​​the second region 232, thereby reducing the thickness of the liquid solder within the first region 231 and preventing the LED beads 122 from tilting. Furthermore, with a fixed surface area of ​​the pads 23, forming the first edge 1 through the cutout area 233 reduces the overall size of the pads 23, allowing for a more compact arrangement of the LED beads 122 in the backlight panel 120. Additionally, the liquid solder within the second region 232 can flow freely, resulting in a more uniform solder distribution.

[0109] Referring again to Figure 17, the cutout area 233 divides the second area 232 into a first sub-area 232a and a second sub-area 232b. The first sub-area 232a is located at the first end 11, and the second sub-area 232b is located at the second end 12. For example, the first sub-area 232a can be connected to the left end of the first area 231, and the second sub-area 232b can be connected to the right end of the first area 231. Liquid solder in the first area 231 can flow into the first sub-area 232a from the left end, and liquid solder in the first area 231 can flow into the second sub-area 232b from the right end.

[0110] The first sub-region 232a and the second sub-region 232b are connected on the side away from the first region 231, which can make the area of ​​the second region 232 larger, thereby reducing the thickness of the liquid solder in the first region 231 and preventing the lamp bead 122 from tilting.

[0111] Referring again to FIG17, in some embodiments, the length of the first edge 1 is less than or equal to the length of the second edge 2. Since the second region 232 is located on the side of the first edge 1 away from the first region 231, and the length of the first edge 1 is less than the length of the second edge 2, a channel for the flow of liquid solder can be formed between the first region 231 and the second region 232.

[0112] Referring again to Figure 17, in some embodiments, the dimensions of the first region 231 and the second region 232 along the second direction Y are the widths, the width of the first region 231 is w1, the width of the second region 232 is w2, and the width of the second region 232 is greater than the width of the first region 231, i.e., w1 < w2.

[0113] For example, the first region 231 has a third edge 3 and a fourth edge 4, which are arranged relative to each other along the second direction Y. The third edge 3 may be recessed inwards by a certain distance relative to the edge of the second region 232, or the fourth edge 4 may be recessed inwards by a certain distance relative to the edge of the second region 232, or both the third edge 3 and the fourth edge 4 may be recessed inwards by a certain distance relative to the edge of the second region 232.

[0114] Figure 18 is a schematic diagram of another type of pad 23 in an embodiment of this disclosure. As shown in Figure 18, the width of the pad 23 region can gradually increase along the direction toward the second region 232. This can reduce the area of ​​the blank regions on both sides of the first region 231. When some solder paste is applied to the blank regions, the solder in the solder paste located in the blank regions is more easily adsorbed onto the pad 23, thereby improving the solder ball problem.

[0115] For example, the third edge 3 and / or the fourth edge 4 are inclined at a certain angle relative to the second edge 2. For example, the first region 231 is inverted trapezoidal.

[0116] Figure 19 is a schematic diagram of another pad 23 in an embodiment of this disclosure. As shown in Figure 19, in some embodiments, the first edge 1 includes multiple sub-edges, which are spaced apart along the second direction Y. The simultaneous provision of multiple first edge segments 1, arranged along the second direction Y, makes it more difficult for the pin 10 to cross the first edge 1 into the second region 232.

[0117] For example, the first edge 1 includes a first sub-edge 1a and a second sub-edge 1b. The first sub-edge 1a is located on the left side of the first region 231, and the second sub-edge 1b is located on the right side of the first region 231. The first sub-edge 1a located on the left side can restrict the left end of the pin 10 from entering the second region 232, and the second sub-edge 1b located on the right side can restrict the right end of the pin 10 from entering the second region 232.

[0118] Furthermore, relative to the aforementioned pad 23, the first edge 1 includes a first sub-edge 1a and a second sub-edge 1b. When the first sub-edge 1a is located on the left side of the first region 231 and the second sub-edge 1b is located on the right side of the first region 231, the rotation of the pin 10 in the first region 231 can be better restricted, resulting in better positional accuracy of the pin 10.

[0119] Referring again to FIG19, in some embodiments, the pad 23 further includes a connection region 234 located between the second region 232 and the first region 231, and the connection region 234 is located between two adjacent sub-edges, with the second region 232 connected to the first region 231 through the connection region 234. During the pad 23 soldering process, solder in the first region 231 flows into the second region 232 through the connection region 234.

[0120] The second region 232 is connected to the first region 231 through the connecting region 234, thus creating a gap between the first region 231 and the second region 232. During the soldering process, there is no liquid solder in the gap, making it difficult for the pin 10 to cross the gap between the second region 232 and the connecting region 234 and enter the second region 232.

[0121] Figure 20 is a schematic diagram of another pad 23 in an embodiment of this disclosure. As shown in Figure 20, in some embodiments, the first region 231 and the second region 232 are disconnected, that is, the first region 231 and the second region 232 are not connected.

[0122] During pre-application of solder paste, part of the solder paste is located in the first region 231, and part of the solder paste is located in the second region 232. The solder in the first region 231 melts and covers the first region 231, and the solder in the second region 232 melts and covers the second region 232. In practical applications, part of the solder paste can also be located between the second region 232 and the first region 231. The solder in this portion of the solder paste, after melting, can be absorbed into either the second region 232 or the first region 231.

[0123] The first region 231 and the second region 232 are disconnected, creating a certain distance between them. This makes it difficult for the pin 10 located in the first region 231 to easily move from the first region 231 into the second region 232. Furthermore, because the first region 231 and the second region 232 are disconnected, the shape and area of ​​the first region 231 can match the shape and area of ​​the pin 10, thereby improving the positional accuracy of the pin 10 within the first region 231.

[0124] This disclosure also provides an electronic device, which includes a substrate 121, solder, and electronic components. The surface of the substrate 121 is provided with pads 23, each pad including a first region 231 and a second region 232. The surfaces of the first region 231 and the second region 232 are used to connect the solder, and external components are soldered to the first region 231. The first region 231 has a first edge 1 and a second edge 2, which are opposite to each other along a first direction X. At least a portion of the second region 232 is located on the side of the first edge 1 away from the second edge 2. The solder is located on the surfaces of the first region 231 and the second region 232. The electronic components are provided with pins 10, which are connected to the solder within the first region 231, and the pins 10 are located between the first edge 1 and the second edge 2. This disclosure does not limit the type of electronic device.

[0125] The electronic components of the electronic device are connected to the substrate 121 via surface mount technology (SMT). The electronic components have pins 10, which are soldered to pads 23.

[0126] In the electronic device provided in this embodiment, during the soldering process between the pin 10 and the pad 23, the liquid solder is confined to the area within the surface of the pad 23, that is, the liquid solder is confined to the area enclosed by the edge of the pad 23. When the pin 10 is placed on the pad 23, since the pin 10 can only float within the area of ​​the liquid solder, that is, the pin 10 can only be within the area enclosed by the edge of the pad 23. The pin 10 is placed in the soldering area, that is, the pin 10 is located between the first edge 1 and the second edge 2. The pin 10 is confined between the first edge 1 and the second edge 2, and cannot cross the first edge 1 into the second region 232, reducing the floating range of the pin 10, thereby making it less likely for the LED bead 122 to deviate from the preset position and improving the positional accuracy of the LED bead 122.

[0127] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A substrate, characterized in that, The surface of the substrate is provided with: The pad includes a first region and a second region, the first region having a first edge and a second edge, the first edge and the second edge being opposite each other along a first direction, and at least a portion of the second region being located on the side of the first edge away from the second edge; A solder mask layer, a portion of which is located on the side of the first edge away from the first region.

2. The substrate according to claim 1, characterized in that, The first region and the second region are connected as a single structure.

3. The substrate according to claim 2, characterized in that, The first edge includes a first end and a second end opposite to each other, and the second region includes a first sub-region and a second sub-region, wherein the first sub-region is located at the first end and the second sub-region is located at the second end.

4. The substrate according to claim 3, characterized in that, The first sub-region and the second sub-region are separated on the side away from the first region.

5. The substrate according to claim 3, characterized in that, The first sub-region and the second sub-region are connected on the side away from the first region.

6. The substrate according to claim 1, characterized in that, The first edge comprises multiple edge segments, which are spaced apart along a second direction; the second direction is perpendicular to the first direction.

7. The substrate according to claim 6, characterized in that, The pad also includes a connection area located between the second region and the first region. The connection area is located between two adjacent sub-edges, and the second region is connected to the first region through the connection area.

8. The substrate according to claim 1, characterized in that, The first region is disconnected from the second region.

9. The substrate according to any one of claims 1 to 8, characterized in that, The length of the first edge is less than or equal to the length of the second edge.

10. The substrate according to any one of claims 1 to 8, characterized in that, The dimensions of the first region and the second region along the second direction are their widths, with the width of the second region being greater than the width of the first region; the second direction is perpendicular to the first direction.

11. The substrate according to claim 10, characterized in that, The width of the pad area gradually increases along the direction toward the second region.

12. The substrate according to any one of claims 1 to 8, characterized in that, The solder pad is surrounded by a solder resist layer, which is disposed in the same layer as the solder pad.

13. The substrate according to claim 1, characterized in that, The pads include a first pad and a second pad, the first pad and the second pad are arranged at intervals along the first direction, and the first areas of the first pad and the second pad are arranged opposite to each other.

14. A backlight panel, characterized in that, include: A substrate, the surface of which is provided with pads and a solder mask layer, the pads including a first region and a second region, the first region having a first edge and a second edge, the first edge and the second edge being opposite each other along a first direction, at least a portion of the second region being located on the side of the first edge away from the second edge, and a portion of the solder mask layer being located on the side of the first edge away from the first region. Solder, the solder being located on the surfaces of the first region and the second region; The lamp bead has pins that are connected to solder within the first region and are located between the first edge and the second edge.

15. An electronic device, characterized in that, include: A substrate, the surface of which is provided with pads and a solder mask layer, the pads including a first region and a second region, the first region having a first edge and a second edge, the first edge and the second edge being opposite each other along a first direction, at least a portion of the second region being located on the side of the first edge away from the second edge, and a portion of the solder mask layer being located on the side of the first edge away from the first region. Solder, the solder being located on the surfaces of the first region and the second region; An electronic device having pins connected to solder within a first region, the pins being located between the first edge and the second edge.

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