Circuit board, display module and display device

Abstract

The present application relates to a circuit board, a display module and a display device. The circuit board includes a circuit board body, a pad arrangement area is provided on the circuit board body, a plurality of pad groups are arranged in an array in the pad arrangement area, and the pad groups are used for soldering chips; at least two pad groups located at the edge of the pad arrangement area are respectively provided with extension parts, the extension parts are located on one side of the at least two pad groups close to the edge of the pad arrangement area, and the extension parts are used for detecting the alignment of the chips and the pad groups. In this way, during mass transfer, the positional relationship between the extension parts and the chips (such as whether the extension parts are exposed or whether the extension parts are parallel to the chips, etc.) can be detected by auxiliary means to obtain the alignment situation of the chips and the pad groups, which is convenient for correcting the alignment of the two, improving the alignment defect of the chips and the pad groups, and improving the mass transfer yield.

Description

Technical Field

[0001] The present application relates to the field of display technologies, and particularly to a circuit board, a display module, and a display device. Background Art

[0002] In the manufacturing process of displays such as Mini-LED displays and Micro-LED displays with a number of small-sized chips, it is usually necessary to transfer micro-chips such as Micro-LEDs or Mini-LEDs grown on a substrate to a driving circuit board by means of mass transfer.

[0003] In the related art, as shown in Figure 1 and Figure 2 , a commonly used mass transfer method is to first align chip 1 with circuit board 4. Specifically, align chip pad 2 with circuit board pad 5, and then heat the tin layer 3 between chip pad 2 and circuit board pad 5 by laser to weld and bond chip pad 2 and circuit board pad 5. However, due to the very small size of chip 1, as shown in Figure 3 , chip pad 2 cannot be accurately aligned with circuit board pad 5, resulting in poor welding between chip pad 2 and circuit board pad 5 and a low mass transfer yield. Summary of the Invention

[0004] Based on this, it is necessary to provide a circuit board, a display module, and a display device for solving the problem of low mass transfer yield of chips in the traditional technology.

[0005] A first aspect of an embodiment of the present application provides a circuit board, including a circuit board body, where a pad arrangement area is provided on the circuit board body, and a plurality of pad groups are arranged in an array in the pad arrangement area, and the pad groups are used for welding chips;

[0006] At least two pad groups located at the edge of the pad arrangement area are respectively provided with extension parts, the extension parts are located on the side of the at least two pad groups close to the edge of the pad arrangement area, and the extension parts are used for detecting the alignment of the chips and the pad groups.

[0007] In the above circuit board, by providing extension parts on at least two pad groups located at the edge of the pad arrangement area, during mass transfer, the positional relationship between the extension parts and the chips (such as whether the extension parts are exposed or whether the extension parts are parallel to the chips) can be detected by auxiliary means to obtain the alignment situation of the chips and the pad groups, which is convenient for correcting their alignment, improving the misalignment between the chips and the pad groups, and increasing the mass transfer yield. In addition, even when the chip pitch is small, the above arrangement can also be used to assist in detecting the alignment situation of the chips and the pad groups, ensuring the alignment yield.

[0008] In one embodiment, the multiple pad groups are arranged in an array along a first direction and a second direction, wherein the first direction is perpendicular to the second direction;

[0009] A first positioning edge and a second positioning edge are provided on the extension portion; wherein, the extending direction of the first positioning edge is parallel to the first direction; the extending direction of the second positioning edge is parallel to the second direction.

[0010] In one embodiment, the number of both the first positioning edge and the second positioning edge is two;

[0011] Wherein, the two first positioning edges are spaced apart in the second direction, and the distance between the two first positioning edges is equal to the length of the chip in the second direction; the two second positioning edges are spaced apart in the first direction, and the distance between the two second positioning edges is equal to the length of the chip in the first direction.

[0012] In one embodiment, the pad group includes at least two first pad groups; one side of the first pad group in the first direction and one side of the first pad group in the second direction are both located at the edge of the pad arrangement area;

[0013] The extension portion is provided on one side of the first pad group along the first direction close to the edge of the pad arrangement area and on one side of the first pad group along the second direction close to the edge of the pad arrangement area.

[0014] In one embodiment, at least two of the first pad groups are arranged along the diagonal of the pad arrangement area.

[0015] In one embodiment, the first pad group includes a first sub-pad and a second sub-pad arranged at intervals in the first direction;

[0016] One side of the first sub-pad in the first direction and one side of the first sub-pad in the second direction are both located at the edge of the pad arrangement area;

[0017] One side of the second sub-pad in the second direction is located at the edge of the pad arrangement area.

[0018] In one embodiment, a first extension portion is provided on one side of the first sub-pad along the first direction close to the edge of the pad arrangement area; the two side edges of the first extension portion in the second direction are the first positioning edges;

[0019] The first sub-pad and the second sub-pad are both provided with a second extension portion on one side close to the edge of the pad arrangement area along the second direction; and two sides of the two second extension portions facing away from each other in the first direction are the second positioning edges.

[0020] In one embodiment, the length of the first positioning edge in the first direction is not less than 40 μm;

[0021] And / or, the length of the second positioning edge in the second direction is not less than 40 μm.

[0022] A second aspect of the embodiments of the present application provides a display module, comprising a plurality of chips and the circuit board as described in the first aspect, wherein the plurality of chips are soldered to the plurality of solder pad groups in a one-to-one correspondence;

[0023] The orthographic projection of the extension portion on the circuit board body does not overlap with the orthographic projection of the chip on the circuit board body.

[0024] The display module described above, by providing extensions on at least two pad groups located at the edge of the pad arrangement area, allows for auxiliary means to detect the positional relationship between the extensions and the chip (such as whether the extensions are exposed or whether the extensions are parallel to the chip) during mass transfer, thereby obtaining the alignment of the chip and the pad group. This facilitates correction of the alignment between the two, improves poor alignment between the chip and the pad group, and increases the mass transfer yield, thereby improving the yield rate of the display module. Furthermore, even when the chip spacing is small, the above-mentioned arrangement can assist in detecting the alignment of the chip and the pad group, ensuring the alignment yield rate.

[0025] In one embodiment, the side of the chip in the first direction is flush with the second positioning edge of the extension portion; the side of the chip in the second direction is flush with the first positioning edge of the extension portion; wherein the first direction is perpendicular to the second direction.

[0026] A third aspect of an embodiment of the present application provides a display device, comprising the display module of the second aspect.

[0027] The above-mentioned display device, by arranging extensions on at least two pad groups located at the edge of the pad arrangement area, allows auxiliary means to be used to detect the positional relationship between the extension and the chip (such as whether the extension is exposed or whether the extension is parallel to the chip, etc.) during mass transfer, to obtain the alignment of the chip and the pad group, thereby facilitating correction of the alignment between the two, improving poor alignment between the chip and the pad group, and improving the mass transfer yield, thereby improving the manufacturing yield of the display device. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0029] Figure 1 Schematic diagram of chip mass transfer in the prior art;

[0030] Figure 2 Schematic diagram of laser application during mass transfer in the prior art;

[0031] Figure 3 Schematic diagram of poor alignment between the chip and the circuit board in the prior art;

[0032] Figure 4 Schematic diagram of chip mass transfer in the related art;

[0033] Figure 5 For Figure 4 Top view;

[0034] Figure 6 Schematic diagram of chip arrangement in the related art;

[0035] Figure 7 Schematic diagram of the structure of the circuit board provided by an embodiment of the present application;

[0036] Figure 8 Top view of a circuit board and a chip after welding provided by an embodiment of the present application;

[0037] Figure 9 For Figure 8 Detailed schematic diagram of part I in

[0038] Figure 10 For Figure 8 Detailed schematic diagram of part II in

[0039] Figure 11 Top view of another circuit board and a chip after welding provided by an embodiment of the present application;

[0040] Figure 12 Top view of yet another circuit board and a chip after welding provided by an embodiment of the present application;

[0041] Figure 13 Top view of yet another circuit board and a chip after welding provided by an embodiment of the present application;

[0042] Figure 14 Top view of yet another circuit board and a chip after welding provided by an embodiment of the present application;

[0043] Figure 15 Another structural schematic diagram of an extension part and a pad group provided by an embodiment of the present application;

[0044] Figure 16 Yet another structural schematic diagram of an extension part and a pad group provided by an embodiment of the present application;

[0045] Figure 17 Still another structural schematic diagram of an extension part and a pad group provided by an embodiment of the present application.

[0046] Reference numerals:

[0047] 1 - Chip; 2 - Chip pad; 3 - Tin layer; 4 - Circuit board; 5 - Circuit board pad;

[0048] 100 - Circuit board; 110 - Circuit board body; 111 - Pad arrangement area; 120 - Pad group; 121 - First pad group; 1211 - First sub - pad; 1212 - Second sub - pad; 122 - Second pad group; 130 - Extension part; 130a - First positioning edge; 130b - Second positioning edge; 131 - First extension part; 132 - Second extension part;

[0049] 200 - Chip; Detailed implementation manners

[0050] To make the above - mentioned objects, features, and advantages of the present application more obvious and understandable, the following describes the detailed implementation manners of the present application with reference to the accompanying drawings. Many specific details are set forth in the following description in order to fully understand the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present application. Therefore, the present application is not limited by the specific embodiments disclosed below.

[0051] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present application.

[0052] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of this application, "a plurality of" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0053] In this application, unless otherwise clearly defined and limited, terms such as "mounted", "connected", "coupled", "fixed", etc. shall be construed in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0054] In this application, unless otherwise clearly defined and limited, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0055] It should be noted that when an element is referred to as "fixed to" or "disposed on" another element, it may be directly on the other element or there may also be an intermediate element. When an element is considered to be "connected" to another element, it may be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "above", "below", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only embodiments.

[0056] As used herein, the singular forms "a", "an" and "the" may also include the plural forms unless the context clearly dictates otherwise. It should also be understood that the terms "comprises / comprising" or "has / including" etc. specify the presence of the stated features, wholes, steps, operations, components, parts or combinations thereof, but do not preclude the presence or addition of one or more other features, wholes, steps, operations, components, parts or combinations thereof. At the same time, in this specification, the term "and / or" includes any and all combinations of the related listed items.

[0057] Referring to Figure 4 and Figure 5 As shown, in the related art, in order to improve the alignment accuracy between the chip pad 2 and the circuit board pad 5, the surface area of the circuit board pad 5 is increased by enlarging the size of the circuit board pad 5. In this way, when the chip pad 2 on the chip 1 is aligned with the circuit board pad 5 on the circuit board 4, even if the position of the chip 1 shifts slightly, the alignment accuracy between the chip pad 2 and the circuit board pad 5 can be ensured. At the same time, the tin layer 3 can also be in good contact with the circuit board pad 5, improving the soldering yield between the chip pad 2 and the circuit board pad 5.

[0058] However, referring to Figure 6 As shown, in a high-resolution display, since the distance L between the chips 1 is small and the space on the circuit board 4 is limited. Therefore, it is impossible to improve the alignment accuracy between the chip pad and the circuit board pad by enlarging the size of the circuit board pad.

[0059] In view of this, in order to solve at least one problem in the background art and the related art, an embodiment of the present application provides a circuit board, a display module and a display device.

[0060] In a first aspect, an embodiment of the present application provides a circuit board 100, which can be a printed circuit board (PCB). A plurality of signal lines are arranged on the printed circuit board to drive the chip 200.

[0061] As Figure 7 described, the circuit board 100 includes a circuit board body 110. A pad arrangement area 111 is provided on the circuit board body 110. A plurality of pad groups 120 are arranged in an array in the pad arrangement area 111. The pad groups 120 are used for soldering the chip 200. It can be understood that the pad arrangement area 111 is a virtual area for arranging the pad groups 120. After the circuit board 100 is soldered to the chip 200, a display module can be formed. The display module has a display area, and the pad arrangement area 111 can correspond to the display area.

[0062] Specifically, extension parts 130 are respectively arranged on at least two pad groups 120 located at the edge of the pad arrangement area 111. The extension parts 130 are located on one side of the at least two pad groups 120 close to the edge of the pad arrangement area 111, and the extension parts 130 are used to detect the alignment between the chip 200 and the pad groups 120.

[0063] It can be understood that in the outermost pad groups 120, at least one side of each pad group 120 is an open area (i.e., near the edge of the pad arrangement area 111). At least two pad groups 120 are selected from these pad groups 120, and extension parts 130 are respectively arranged on the at least two pad groups 120, and the extension parts 130 are located on one side of the "open area" of the pad groups 120.

[0064] It should be noted that when detecting the alignment between the detection chip 200 and the pad group 120, a CCD (Charge Coupled Device) camera can be used for detection. The detection method can be any one of the following listed, for example: whether the expected exposed part of the extension part 130 is exposed; whether the size of the exposed part of the extension part 130 conforms to the expected size; and whether a specific part of the extension part 130 is parallel to the chip 200, etc.

[0065] It should be noted that optical positioning holes are also arranged on the circuit board body 110, and the optical positioning holes are located outside the pad arrangement area 111. Before mass transfer, first measure the positions of the optical positioning holes on the circuit board 100, calculate the positions where each chip 200 is to be placed, and then preliminarily align the chip 200 and the circuit board 100 according to the calculated positions. Secondly, detect the alignment between the chip 200 and the pad group 120 in the above manner to facilitate correcting their alignment and improving the poor alignment between the chip 200 and the pad group 120.

[0066] For the above circuit board 100, by arranging the extension parts 130 on at least two pad groups 120 located at the edge of the pad arrangement area 111, during mass transfer, the positional relationship between the extension parts 130 and the chip 200 can be detected by auxiliary means (such as whether the extension parts 130 are exposed or whether the extension parts 130 are parallel to the chip 200, etc.) to obtain the alignment situation between the chip 200 and the pad group 120, which is convenient for correcting their alignment, improving the poor alignment between the chip 200 and the pad group 120, and increasing the mass transfer yield. In addition, since the extension parts 130 are arranged on the outermost pad groups 120 and are located on the side of the outermost pad groups 120 close to the edge of the pad arrangement area 111, the arrangement of the chips 200 will not be affected. That is: even when the chip pitch is small, the alignment situation between the chip 200 and the pad group 120 can also be detected. The problem that it is difficult to detect the alignment between the chip 200 and the pad group 120 due to the small chip pitch is solved.

[0067] It can be understood that the minimum number of pad groups 120 provided with the extension parts 130 is two, because when detecting two extension parts 130, the alignment situation between all the chips 200 and the pad groups 120 can be relatively accurately obtained.

[0068] In one embodiment, referring to Figure 7 , Figure 8 and Figure 9 as shown, a plurality of pad groups 120 are arranged in an array along a first direction a and a second direction b, wherein the first direction a is perpendicular to the second direction b. The extension portion 130 is provided with a first positioning edge 130a and a second positioning edge 130b; wherein, the extending direction of the first positioning edge 130a is parallel to the first direction a; the extending direction of the second positioning edge 130b is parallel to the second direction b.

[0069] In this way, when detecting the alignment of the detection chip 200 with the pads, by detecting whether the side of the detection chip 200 in the first direction a is parallel or flush with the second positioning edge 130b, and whether the side of the chip 200 in the second direction b is parallel or flush with the first positioning edge 130a, it is possible to obtain whether the alignment of the chip 200 with the pad group 120 is accurate.

[0070] In one embodiment, referring to Figure 10 as shown, the number of both the first positioning edge 130a and the second positioning edge 130b is two. Among them, the two first positioning edges 130a are arranged at intervals in the second direction b, and the distance W2 between the two first positioning edges 130a is equal to the length of the chip 200 in the second direction b. At the same time, the two second positioning edges 130b are arranged at intervals in the first direction a, and the distance W1 between the two second positioning edges 130b is equal to the length of the chip 200 in the first direction a.

[0071] In this way, by detecting whether the two first positioning edges 130a are flush with the two sides of the chip 200 in the second direction b, it is possible to obtain whether the alignment of the chip 200 with the pad group 120 in the second direction b is accurate. By detecting whether the two second positioning edges 130b are flush with the two sides of the chip 200 in the first direction a, it is possible to obtain whether the alignment of the chip 200 with the pad group 120 in the first direction a is accurate.

[0072] In one embodiment, referring to Figure 7 as shown, the pad group 120 includes at least two first pad groups 121; one side of the first pad group 121 in the first direction a and one side of the first pad group 121 in the second direction b are both located at the edge of the pad arrangement area 111. One side of the first pad group 121 close to the edge of the pad arrangement area 111 in the first direction a and one side of the first pad group 121 close to the edge of the pad arrangement area 111 in the second direction b are both provided with an extension portion 130. In the embodiments of the present application, all the pad groups 120 provided with the extension portion 130 are the first pad groups 121.

[0073] That is to say, if the circuit board 100 and the pad arrangement area 111 are rectangular, the first pad group 121 is located at the "corner" of the pad arrangement area 111. It can be understood that both sides of the first pad group 121 located at the "corner" are "open areas". In this way, extension parts 130 can be arranged on the two sides of the first pad group 121 facing the "open areas", so that the number of extension parts 130 arranged on the first pad group 121 is larger, which is convenient for detecting the alignment of the chip 200 and the pad group 120. It can be understood that with reference to Figure 8 as shown, the rectangular circuit board 100 has four "corners", and any two of the four "corners" can be set as the first pad group 121, or as shown in Figure 11 , all the pad groups 120 at the four "corners" can be set as the first pad group 121.

[0074] In addition, if the circuit board 100 is circular, as shown in Figure 12 , any two pad groups 120 with two "open areas" can be set as the first pad group 121. Preferably, the positions of the two first pad groups 121 can be opposite, that is, they are located on the same virtual diagonal line.

[0075] In a preferred embodiment, as shown in Figure 13 , four first pad groups 121 can also be arranged. The four first pad groups 121 are opposite to each other in pairs and are respectively located on two intersecting virtual diagonal lines.

[0076] In addition, if the circuit board 100 is irregular, as shown in Figure 14 , the pad groups 120 at multiple "corners" can be set as the first pad group 121. It can be understood that due to the different shapes of the circuit board 100, there are also many arrangement ways of the first pad group 121, and the embodiments of the present application will not list them one by one.

[0077] In one of the embodiments, as shown in Figure 10 , the first pad group 121 includes a first sub-pad 1211 and a second sub-pad 1212 arranged at intervals along the first direction a. Among them, the first sub-pad 1211 can be a positive electrode pad, and the second sub-pad 1212 can be a negative electrode pad.

[0078] Specifically, with reference to Figure 8 and Figure 10As shown, one side of the first sub-pad 1211 in the first direction a and one side in the second direction b are both located at the edge of the pad arrangement area 111, that is, one side of the first sub-pad 1211 in the first direction a and one side in the second direction b are both facing the "open area". One side of the second sub-pad 1212 in the second direction b is located at the edge of the pad arrangement area 111, that is, one side of the second sub-pad 1212 in the second direction b faces the "open area".

[0079] Specifically, a first extension portion 131 is provided on one side of the first sub-pad 1211 along the first direction a, close to the edge of the pad arrangement area 111. The two side edges of the first extension portion 131 in the second direction b serve as first positioning edges 130a. Thus, providing a first extension portion 131 allows for detection of the alignment of the chip 200 and the pad group 120 in the second direction b.

[0080] A second extension portion 132 is provided on each of the first sub-pad 1211 and the second sub-pad 1212 along the second direction b, near the edge of the pad arrangement area 111. The two sides of the two second extension portions 132, which are facing away from each other in the first direction a, serve as second positioning edges 130b. Thus, the alignment of the chip 200 and the pad group 120 in the first direction a can be detected using the two second extension portions 132.

[0081] In one embodiment, the length L1 of the first positioning edge 130a in the first direction a is not less than 40 μm; the length L2 of the second positioning edge 130b in the second direction b is not less than 40 μm. It is understood that the longer the lengths of the first positioning edge 130a and the second positioning edge 130b, the more conducive it is to detecting the flushness of the side edges of the chip 200 with the first positioning edge 130a and the second positioning edge 130b.

[0082] like Figure 15 and Figure 16 As shown, the shapes of the first extension portion 131 and the second extension portion 132 are not limited to rectangles, but can also be other irregular shapes. It is only necessary to ensure that the extension direction of the first positioning edge 130a of the first extension portion 131 is parallel to the first direction a, and the extension direction of the second positioning edge 130b of the second extension portion 132 is parallel to the second direction b.

[0083] In the embodiment of the present application, the pad groups 120 that are not provided with the extension portion 130 are all second pad groups 122. The second pad group 122 also includes two sub-pads, and the sub-pads of the second pad group 122 can be the same as the first sub-pad 1211 (or the second sub-pad 1212) of the first pad group 121. At the same time, the shape of the first sub-pad 1211 can be various shapes, such as Figure 17As shown, the outer contour of the first sub-pad 1211 may not coincide with the outer contour of the chip 200.

[0084] In the second aspect of the embodiments of the present application, a display module is provided. Referring to Figure 8 and Figure 9 As shown, the display module includes a plurality of chips 200 and a circuit board 100 as in the first aspect. The plurality of chips 200 are soldered to a plurality of pad groups 120 one by one. The orthographic projection of the extension part 130 on the circuit board body 110 does not coincide with the orthographic projection of the chip 200 on the circuit board body 110.

[0085] The chips in the embodiments of the present application may be mini light-emitting diodes (Mini-LEDs), micro light-emitting diodes (Micro-LEDs), light-emitting diodes (LEDs), or nano-scale LEDs. The embodiments of the present application do not limit this, and the designs of the circuit boards in the above embodiments can be used to achieve good alignment yield and soldering yield.

[0086] In the above display module, by providing extension parts on at least two pad groups at the edge of the pad arrangement area, during mass transfer, the positional relationship between the extension part and the chip (such as whether the extension part is exposed or whether the extension part is parallel to the chip) can be detected by auxiliary means to obtain the alignment situation between the chip and the pad group, which is convenient for correcting their alignment, improving the misalignment between the chip and the pad group, increasing the mass transfer yield, and thus improving the preparation yield of the display module. In addition, when the chip pitch is small, the alignment situation between the chip and the pad group can also be detected, solving the problem that it is difficult to detect the alignment between the chip and the pad group due to the small chip pitch.

[0087] In one of the embodiments, referring to Figure 9 and Figure 10 As shown, the side of the chip 200 in the first direction a is flush with the second positioning edge 130b of the extension part 130; the side of the chip 200 in the second direction b is flush with the first positioning edge 130a of the extension part 130; wherein, the first direction a is perpendicular to the second direction b. In this way, it can be ensured that the chip 200 is accurately aligned with the pad group in the first direction a and the second direction b.

[0088] In the third aspect of the embodiments of the present application, a display device is provided, including the display module of the second aspect.

[0089] The display device may be a terminal such as a television, a monitor, or a mobile phone in the field of display backlighting, or may be a floor lamp, a table lamp, a lighting lamp, a ceiling lamp, a downlight, or a projection lamp in the field of lighting, or may also be various decorative lamps in the field of decoration, such as various colored lights, landscape lighting lamps, or advertising lights.

[0090] In the above display device, by providing extension portions on at least two pad groups located at the edge of the pad arrangement area, during mass transfer, the positional relationship between the extension portions and the chips can be detected by auxiliary means (such as whether the extension portions are exposed or whether the extension portions are parallel to the chips, etc.) to obtain the alignment situation between the chips and the pad groups, facilitating the correction of their alignment, improving the misalignment between the chips and the pad groups, increasing the mass transfer yield, and thus improving the preparation yield of the display device.

[0091] In the description of this specification, the description with reference to terms such as "some embodiments", "other embodiments", "ideal embodiments", etc. means that the specific features, structures, materials, or features described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic description of the above terms does not necessarily refer to the same embodiment or example.

[0092] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features of the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered to be within the scope described in this specification.

[0093] The above-described embodiments only represent several implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the appended claims.

Claims

1. A circuit board, characterized in that, The circuit board comprises a main body, wherein a pad arrangement area is provided on the main body, a plurality of pad groups are arranged in an array in the pad arrangement area, and the pad groups are used for soldering chips; An extension portion is provided on each of at least two pad groups located at an edge of the pad arrangement area. The extension portion is located on a side of the at least two pad groups close to the edge of the pad arrangement area, and the extension portion is used to detect the alignment of the chip and the pad group. The plurality of pad groups are arranged in an array along a first direction and a second direction, wherein the first direction is perpendicular to the second direction; The extension portion is provided with a first positioning edge and a second positioning edge; wherein the extension direction of the first positioning edge is parallel to the first direction; and the extension direction of the second positioning edge is parallel to the second direction; The number of the first positioning edges and the number of the second positioning edges are both two; Among them, the two first positioning edges are arranged at intervals in the second direction, and the distance between the two first positioning edges is equal to the length of the chip in the second direction; the two second positioning edges are arranged at intervals in the first direction, and the distance between the two second positioning edges is equal to the length of the chip in the first direction.

2. The circuit board according to claim 1, wherein The pad group includes at least two first pad groups; one side of the first pad group in the first direction and one side of the first pad group in the second direction are both located at the edge of the pad arrangement area; The extension portion is provided on one side of the first pad group close to the edge of the pad arrangement area along the first direction, and on one side of the first pad group close to the edge of the pad arrangement area along the second direction.

3. The circuit board according to claim 2, wherein, At least two of the first pad groups are arranged along a diagonal line of the pad arrangement area.

4. The circuit board according to claim 2, wherein The first pad group includes first sub-pads and second sub-pads arranged at intervals along the first direction; One side of the first sub-pad in the first direction and one side of the first sub-pad in the second direction are both located at the edge of the pad arrangement area; One side of the second sub-pad in the second direction is located at an edge of the pad arrangement area.

5. The circuit board according to claim 4, characterized in that, A first extension portion is provided on one side of the first sub-pad close to the edge of the pad arrangement area along the first direction; two side edges of the first extension portion in the second direction are the first positioning edges; The first sub-pad and the second sub-pad are both provided with a second extension portion on one side close to the edge of the pad arrangement area along the second direction; and two sides of the two second extension portions facing away from each other in the first direction are the second positioning edges.

6. The circuit board according to claim 1, wherein The length of the first positioning edge in the first direction is not less than 40 μm; And / or, the length of the second positioning edge in the second direction is not less than 40 μm.

7. A display module, characterized in that, comprising a plurality of chips and a circuit board according to any one of claims 1 to 6, wherein the plurality of chips are soldered on the plurality of pad groups in a one-to-one correspondence; The orthographic projection of the extension portion on the circuit board body does not overlap with the orthographic projection of the chip on the circuit board body.

8. The display module according to claim 7, wherein, The side of the chip in the first direction is flush with the second positioning edge of the extension; the side of the chip in the second direction is flush with the first positioning edge of the extension; wherein, the first direction is perpendicular to the second direction.

9. A display device, characterized in that, Comprising the display module according to claim 7 or 8.

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