Circuit board assembly, light emitting assembly and method of making the same

Abstract

The present application relates to a kind of circuit board assembly, light-emitting assembly and its manufacturing method, light-emitting assembly includes circuit board assembly, circuit board assembly includes the circuit board with multiple chip bonding areas, and be arranged on the circuit board, and form multiple cavities of weakening layer, one chip bonding area corresponds one cavity.In transferring chip to the circuit board, directly grown substrate grown with weakening layer is aligned and adhered with light-emitting chip, and the light-emitting chip needing to be transferred is separated from grown substrate and is carried on the top wall of corresponding cavity, pressure is applied to the top wall to make it break so that light-emitting chip directly falls on corresponding chip bonding area;And because the distance between the side of top wall away from the circuit board to the circuit board is greater than or equal to the height of light-emitting chip, when subsequent still needs to continue to transfer chip to other chip bonding area on the circuit board, the light-emitting chip that has been transferred will not interfere with other chips on grown substrate in subsequent transfer process, and transfer efficiency is higher, and transfer cost is lower.

Description

Technical Field

[0001] This invention relates to the field of light-emitting chips, and more particularly to a circuit board assembly, a light-emitting component, and a method for manufacturing the same. Background Technology

[0002] Micro LED is a next-generation display technology. Compared with existing liquid crystal displays, it has higher photoelectric efficiency, higher brightness, higher contrast, and lower power consumption, and can also be combined with flexible panels to achieve flexible displays.

[0003] A Micro LED display panel comprises several subpixel rendering (SPR) areas, each containing a red, blue, and green Micro LED chip. During the panel fabrication process, these chips need to be transferred from their respective growth substrates (WAFER) to the display backplane. For example, the transfer process for the Micro LED chips is as follows:

[0004] The side of the temporary substrate with the first adhesive layer is attached to the side of the growth substrate on which the red Micro LED chip is grown. Then the growth substrate is peeled off and the red Micro LED chip is transferred to the temporary substrate.

[0005] The side of the transfer substrate with the second adhesive layer is attached to the side of the temporary substrate that carries the red Micro LED chip, thereby selectively picking up the corresponding red Micro LED chip from the temporary substrate.

[0006] The red Micro LED chip picked up by the transfer substrate is transferred to the corresponding chip bonding area on the display backplane.

[0007] The blue Micro LED chip and the green Micro LED chip are also transferred to the display backplane using the same chip transfer process described above.

[0008] In the chip transfer process described above, two adhesive materials need to be selected to make the first adhesive layer and the second adhesive layer respectively. It is also necessary to ensure that the adhesion of the first adhesive layer is lower than that of the second adhesive layer. It is difficult to find suitable materials. In addition, the transfer process requires transferring the Micro LED chip from the growth substrate to the temporary substrate and from the temporary substrate to the transfer substrate. The transfer efficiency is low and it is necessary to prepare the temporary substrate and the transfer substrate. The transfer cost is also high.

[0009] Therefore, improving the transfer efficiency of LED chips and reducing transfer costs are urgent problems that need to be solved. Summary of the Invention

[0010] In view of the shortcomings of the prior art, the purpose of this invention is to provide a circuit board assembly, a light-emitting component and a method for manufacturing the same, in order to solve the problem of how to improve the transfer efficiency of LED chips and reduce the transfer cost in related technologies.

[0011] This invention provides a circuit board assembly, comprising:

[0012] A circuit board having multiple chip bonding areas, each chip bonding area containing pads corresponding to the electrodes of a light-emitting chip, wherein:

[0013] The circuit board assembly also includes a weakening layer disposed on the circuit board and having multiple cavities formed thereon;

[0014] The plurality of cavities are isolated from each other by the weakening layer, and one chip bonding area corresponds to one cavity. The weakening layer forms the sidewall and top wall of each cavity.

[0015] The top wall is used to support the light-emitting chip detached from the growth substrate, and to break under pressure so that the supported light-emitting chip falls onto the corresponding chip bonding area; the distance between the side of the top wall away from the circuit board and the circuit board is greater than or equal to the height of the light-emitting chip.

[0016] The aforementioned circuit board assembly has a weakening layer covering each chip bonding area, and the weakening layer forms cavities corresponding to and isolated from each chip bonding area. When transferring chips to the circuit board, the side of the growth substrate with the light-emitting chip grown can be directly aligned and bonded to the weakening layer, and the light-emitting chip to be transferred can be detached from the growth substrate, so that the light-emitting chip is supported on the top wall of the corresponding cavity. Then, pressure is applied to the top wall to break it, so that the light-emitting chip falls directly onto the corresponding chip bonding area. Since the distance between the side of the top wall away from the circuit board and the circuit board is greater than or equal to the height of the light-emitting chip, when it is necessary to transfer chips to other chip bonding areas on the circuit board in the future, since the already transferred light-emitting chip is located in the cavity, the already transferred light-emitting chip will not interfere with other chips on the growth substrate in the subsequent transfer process, thereby ensuring the normal transfer of subsequent light-emitting chips. It is evident that when transferring light-emitting chips to this circuit board assembly, it is not necessary to transfer the light-emitting chips from the growth substrate to the temporary substrate and then from the temporary substrate to the transfer substrate. Furthermore, it is no longer necessary to prepare temporary substrates and transfer substrates, resulting in higher transfer efficiency and lower transfer costs.

[0017] Based on the same inventive concept, the present invention also provides a light-emitting component, comprising:

[0018] The circuit board assembly as described above;

[0019] The light-emitting chip is located in each of the chip bonding areas. After the light-emitting chip is detached from the growth substrate, it is supported by the top wall. After the top wall is broken by pressure, it falls onto the corresponding chip bonding area. The electrodes of the light-emitting chip are connected to the pads in the chip bonding area.

[0020] The light-emitting component is made using the circuit board assembly. Since the light-emitting chip is transferred to the circuit board assembly, it is not necessary to transfer the light-emitting chip from the growth substrate to the temporary substrate and then from the temporary substrate to the transfer substrate. It is also not necessary to prepare the temporary substrate and the transfer substrate. The chip transfer efficiency is higher and the transfer cost is lower, which makes the manufacturing efficiency of the light-emitting component higher and the manufacturing cost lower.

[0021] Based on the same inventive concept, the present invention also provides a method for manufacturing the circuit board assembly as described above, comprising:

[0022] A sacrificial layer is formed on the circuit board. The sacrificial layer includes a plurality of sacrificial layer units that cover each of the chip bonding regions, and the sacrificial layer units are separated from each other.

[0023] A weakening layer is formed on the circuit board to cover each of the sacrificial layer units;

[0024] The space occupied by each sacrificial layer unit is removed to form the cavity.

[0025] The circuit board assembly produced by the above-mentioned method of manufacturing circuit board assembly has higher chip transfer efficiency and lower transfer cost because when transferring the light-emitting chip to the circuit board assembly, it is no longer necessary to transfer the light-emitting chip from the growth substrate to the temporary substrate and then from the temporary substrate to the transfer substrate, and it is also no longer necessary to prepare the temporary substrate and the transfer substrate.

[0026] Based on the same inventive concept, the present invention also provides a method for manufacturing the light-emitting component as described above, comprising:

[0027] The side of the growth substrate on which the light-emitting chip is grown is aligned and bonded to the weakening layer on the circuit board. After alignment and bonding, the light-emitting chip contacts the top wall.

[0028] The corresponding light-emitting chip on the growth substrate is peeled off from the growth substrate, and the growth substrate is removed. The peeled-off light-emitting chip is carried on the top wall.

[0029] Pressure is applied to the top wall carrying the light-emitting chip to cause it to break, so that the light-emitting chip carried by the top wall falls onto the corresponding chip bonding area;

[0030] Connect the electrodes of the light-emitting chip to the corresponding pads in the chip bonding area.

[0031] The above method for manufacturing light-emitting components eliminates the need to transfer the light-emitting chip from the growth substrate to the temporary substrate and then from the temporary substrate to the transfer substrate when transferring the light-emitting chip to the circuit board assembly. It also eliminates the need to prepare temporary substrates and transfer substrates. The chip transfer efficiency is higher and the transfer cost is lower, resulting in higher manufacturing efficiency and lower manufacturing cost for the light-emitting component. Attached Figure Description

[0032] Figure 1-1 This is a schematic diagram showing the transfer of three colors of Micro LED chips from the growth substrate to the display backplane in the related technology.

[0033] Figure 1-2 This is a schematic diagram illustrating the process of transferring red-light Micro LED chips in related technologies;

[0034] Figure 1-3 This is a schematic diagram of the bonding area between the temporary substrate and the growth substrate in the related technology;

[0035] Figure 1-4 This is a schematic diagram of a temporary substrate carrying a red Micro LED chip in a related technology.

[0036] Figure 1-5 This is a schematic diagram of a temporary substrate after some of the red Micro LED chips have been removed in the related technology.

[0037] Figure 1-6 A schematic diagram of the display backplane after Micro LED chip transfer and bonding;

[0038] Figure 2 A schematic diagram of the circuit board assembly structure provided in an embodiment of the present invention;

[0039] Figure 3 A schematic diagram of the circuit board assembly structure provided in an embodiment of the present invention. Figure 2 ;

[0040] Figure 4 A schematic diagram of the circuit board assembly structure provided in an embodiment of the present invention. Figure 3 ;

[0041] Figure 5 This is a schematic diagram of a circuit board assembly manufacturing method provided in another optional embodiment of the present invention;

[0042] Figure 6 A schematic diagram of the circuit board assembly manufacturing process provided in another optional embodiment of the present invention;

[0043] Figure 7A schematic diagram of the circuit board assembly manufacturing process provided for another optional embodiment of the present invention. Figure 2 ;

[0044] Figure 8 A schematic diagram of the light-emitting component structure provided in another optional embodiment of the present invention;

[0045] Figure 9 A schematic diagram of the light-emitting component structure provided in another optional embodiment of the present invention. Figure 2 ;

[0046] Figure 10 A schematic diagram of the light-emitting component structure provided in another optional embodiment of the present invention. Figure 3 ;

[0047] Figure 11 This is a schematic diagram of a method for manufacturing a light-emitting component according to another optional embodiment of the present invention;

[0048] Figure 12 A schematic diagram of the first light-emitting chip transfer process provided in another optional embodiment of the present invention;

[0049] Figure 13 A schematic diagram of the second light-emitting chip transfer process provided in another optional embodiment of the present invention;

[0050] Figure 14 A schematic diagram of the third light-emitting chip transfer process provided in another optional embodiment of the present invention;

[0051] Explanation of reference numerals in the attached figures:

[0052] 10-Growth substrate, 101-Red Micro LED chip, 102-Chip vacancy, 20-Temporary substrate, 201-First adhesive layer, 30-Transfer substrate, 301-Second adhesive layer, 302-Display backplate, 4-Circuit board, 40-Chip bonding area, 41-Pad, 5-Weakening layer, 50-Cavity, 51-Top wall, 52-Side wall, 6-Light-emitting chip, 60-Electrode, 61-First light-emitting chip, 62-Second light-emitting chip, 63-Third light-emitting chip, 7-Sacrificial layer unit, 81-First growth substrate, 82-Second growth substrate, 83-Third growth substrate. Detailed Implementation

[0053] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0054] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0055] In Micro LED display technology, see Figure 1-1 As shown, the red, blue, and green Micro LED chips need to be transferred from their respective growth substrates to the display backplane. For example, the transfer process for the red Micro LED chip is described in [link to documentation]. Figures 1-2 to 1-5 As shown, it includes:

[0056] S201: The side of the temporary substrate 20 with the first adhesive layer 201 is bonded to the side of the growth substrate 10 on which the red MicroLED chip 101 is grown; see one top view after bonding. Figure 1-3 As shown;

[0057] S202 to S203: The growth substrate 10 is peeled off, and the red Micro LED chip 101 is transferred onto the temporary substrate 20; a top view of the temporary substrate 20 at this time is shown below. Figure 1-4 As shown;

[0058] S204: The side of the transfer substrate 30 with the second adhesive layer 301 is bonded to the side of the temporary substrate 20 carrying the red MicroLED chip 101, thereby selectively picking up the corresponding red MicroLED chip 101 from the temporary substrate 20; see Figure 1-5 As shown, after the red Micro LED chip at the corresponding position on the temporary substrate 20 is picked up, a corresponding chip empty space 102 is left.

[0059] S205: Transfer the red Micro LED chip picked up by the transfer substrate 30 to the corresponding chip bonding area on the display backplate 302.

[0060] The blue and green Micro LED chips were also transferred to the display backplane using the same chip transfer process described above. For the display backplane that completes the transfer of all Micro LED chips, see [link to relevant documentation]. Figure 1-6 As shown.

[0061] In the chip transfer process described above, two adhesive materials need to be selected to make the first adhesive layer 201 and the second adhesive layer 301 respectively. It is also necessary to ensure that the adhesion of the first adhesive layer 201 is lower than that of the second adhesive layer 301. It is difficult to find suitable materials. In addition, the transfer process requires transferring the Micro LED chip from the growth substrate 10 to the temporary substrate 20 and from the temporary substrate 20 to the transfer substrate 30. The transfer efficiency is low and the temporary substrate 20 and the transfer substrate 30 need to be prepared. The transfer cost is also high.

[0062] Based on this, the present invention aims to provide a solution that can solve the above-mentioned technical problems, the details of which will be described in subsequent embodiments.

[0063] This embodiment provides a circuit board assembly, including:

[0064] The circuit board in this embodiment can be a display back panel, or various circuit boards for lighting, and can be a flexible circuit board or a rigid circuit board. When it is a display back panel, the display back panel can be, but is not limited to, a glass back panel or a PCB board.

[0065] In this embodiment, the circuit board has multiple chip bonding areas, each containing pads corresponding to the electrodes of the light-emitting chip. It should be understood that the number of chip bonding areas and their distribution on the circuit board can be flexibly set according to application requirements. For example, the chip bonding areas can be arranged in an array on the circuit board, or flexibly distributed according to other rules, or even flexibly distributed according to requirements. In some application examples, to facilitate the direct transfer of the light-emitting chip from the growth substrate to the circuit board, the distribution of the chip bonding areas on the circuit board can correspond to the layout and position of the corresponding light-emitting chip on the growth substrate.

[0066] It should be understood that the chip bonding area in this embodiment is not limited to bonding with the light-emitting chip. The light-emitting chip can also be replaced with other electronic chips, such as resistor chips, capacitor chips, driver chips, control chips, etc., depending on the application requirements. These will not be described in detail here.

[0067] It should be understood that the light-emitting chip in this embodiment can be a micro-light-emitting chip, such as at least one of Mini LED chips and Micro LED chips, or a common light-emitting chip with a size greater than or equal to 200 micrometers. Furthermore, the light-emitting chip in this embodiment can be a right-mounted chip, a flip-chip chip, or a vertically mounted chip, which can be flexibly configured according to application requirements. In this embodiment, the light-emitting surface of the light-emitting chip grown on the growth substrate is bonded to the growth substrate.

[0068] The circuit board assembly in this embodiment also includes a weakening layer on the circuit board, wherein multiple cavities are formed thereon;

[0069] The weakening layer forms multiple cavities that are isolated from each other, and one chip bonding area corresponds to one cavity. The corresponding area of ​​the weakening layer itself forms the sidewall and top wall of each cavity. The top wall of each cavity is used to support the light-emitting chip that is detached from the growth substrate. When the top wall is subjected to external pressure, it breaks, allowing the light-emitting chip it supports to fall into the cavity and then onto the chip bonding area corresponding to that cavity.

[0070] In this embodiment, to improve the transfer efficiency of the light-emitting chips, the distance H between the top wall of each cavity away from the circuit board and the circuit board is set to be greater than or equal to the height of the light-emitting chip. Therefore, after the first transfer of the light-emitting chip to the circuit board, when subsequent transfers of chips to other chip bonding areas on the circuit board are required, since the previously transferred light-emitting chips are located in the cavities, and the distance H between the top wall of each cavity away from the circuit board and the circuit board is greater than or equal to the height of the light-emitting chip (i.e., the height of the sidewall of each cavity is greater than the height of the light-emitting chip), the previously transferred light-emitting chips will not interfere with other chips on the growth substrate during the subsequent transfer process, thus ensuring the normal transfer of subsequent light-emitting chips. It is evident that when transferring light-emitting chips to this circuit board assembly, it is not necessary to transfer the light-emitting chips from the growth substrate to the temporary substrate and then from the temporary substrate to the transfer substrate, nor is it necessary to prepare temporary substrates and transfer substrates. This results in higher transfer efficiency and lower transfer costs.

[0071] For ease of understanding, the circuit board assembly provided in this embodiment will be illustrated below with reference to the accompanying drawings.

[0072] See an example of a circuit board assembly. Figure 2 As shown, it includes a circuit board 4, on which multiple chip bonding areas 40 are provided, and each chip bonding area 40 has a pad 41 corresponding to the electrode of the light-emitting chip. See also Figure 2 As shown, the circuit board assembly also includes a weakening layer 5 disposed on the circuit board 4. This weakening layer 5 forms a plurality of cavities 50, which are isolated from each other by the weakening layer 5. Corresponding regions of the weakening layer 5 form the top wall 51 and side wall 52 of each cavity 50. Figure 2 As shown, the distance H between the side of the top wall 51 of each cavity away from the circuit board 4 and the circuit board 4 is greater than or equal to the height of the light-emitting chip. In this embodiment, when there are light-emitting chips of different heights among the light-emitting chips transferred to the circuit board 4, the height of the light-emitting chip in this embodiment is taken as the maximum height value among these light-emitting chips.

[0073] exist Figure 2 In the circuit board assembly shown, the sidewalls 52 of each cavity 50 are separated from each other; however, it should be understood that in this embodiment, the sidewalls 52 of each cavity 50 can also be connected together. For example, see [example description missing]. Figure 3As shown. In some application examples, some sidewalls 52 can be connected together, while some sidewalls 52 can be separated.

[0074] Furthermore, it should be understood that the shape of the cavity 50 in this embodiment can be flexibly set, for example, it can be set to... Figure 2 and Figure 3 The rectangle shown can be replaced with regular shapes such as arcs and trapezoids, or irregular shapes as needed, which will not be elaborated here.

[0075] In some examples, the height of the cavity 50 can be greater than or equal to the height of the light-emitting chip; of course, it can also be slightly less than the height of the light-emitting chip. As long as it can be ensured that after the top wall 51 of the cavity 50 breaks, the light-emitting chip can fall through the cavity 50 onto the corresponding chip bonding area 40, that is, as long as the size of the cavity 50 matches the size of the light-emitting chip, the above purpose can be achieved.

[0076] In some examples of this embodiment, the top wall 51 of the cavity 50 breaks when the light-emitting chip is transferred to the circuit board, but the side wall 52 of the cavity 50 can be retained as needed. When the side wall of the cavity 50 is retained, the weakening layer 5 can be an opaque light-blocking layer. In this case, the side wall of the cavity 50 can also serve as a light-blocking layer, thereby preventing light crosstalk interference between light-emitting chips in adjacent chip bonding areas 40 on the circuit board 4 and improving the display or lighting effect. For example, in some application scenarios, the weakening layer 5 can be set as a black adhesive layer.

[0077] It should be understood that, in some examples of this embodiment, the areas where the weakening layer 5 forms the top wall 51 and side wall 52 of the cavity 50 can be made of the same material, for example, see [reference needed]. Figures 2-3 As shown. However, in other application examples, different materials may also be used, for example, see [link to example]. Figure 4 As shown, the side wall 52 can be made of a material that is not very light, and the top wall 51 can be made of a light-transmitting material or an opaque material.

[0078] In addition, it should be understood that in this embodiment, one light-emitting chip can be set in a chip bonding area 40, or multiple light-emitting chips can be set as needed. When multiple light-emitting chips are set, these multiple light-emitting chips are transferred in one chip transfer process.

[0079] In some examples of this embodiment, the weakening layer 5 can be a hot melt adhesive layer, such as, but not limited to, pyrolytic adhesive or non-conductive adhesive. This way, during the subsequent heating of the electrodes of the light-emitting chip to solder them to the corresponding pads, any adhesive fragments that break off and fall into the cavity 50 can melt and accumulate in the solder-free area, without affecting the soldering of the electrodes to the pads or the light emission of the light-emitting chip. Alternatively, in some examples, the weakening layer 5 can also be a sacrificial material that can be subsequently removed. This sacrificial material can be a non-conductive material, and the weakening layer can be removed after the electrodes of the light-emitting chip are soldered to the corresponding pads.

[0080] In one example of this embodiment, the hot melt adhesive layer may be provided with a certain degree of viscosity, so that when the top wall 51 carries the light-emitting chip from the growth substrate, the light-emitting chip is fixed by the viscosity, which facilitates the separation of the light-emitting chip from the growth substrate and makes the light-emitting chip more stably carried on the top wall 51.

[0081] In some examples of this embodiment, after the light-emitting chip is transferred to the circuit board 4, when the sidewalls 52 of each cavity 50 are retained, at least one of the outer and inner sides of the sidewall 52 can be set as a reflective surface. That is, the cavity 50 and its sidewall 52 can form a reflective cup, thereby improving the light emission efficiency of the light-emitting chip.

[0082] In this embodiment, the thickness and material of the top wall 51 of each cavity 50 can be flexibly selected and configured under the condition that the top wall 51 can support the light-emitting chip and that applying pressure F to it will cause it to break without damaging the light-emitting chip. For example, in one application example, when the weakening layer 5 is made of hot melt adhesive, the thickness of the formed top wall 51 can be less than or equal to 5 micrometers, such as 5 micrometers, 4 micrometers, 3 micrometers, etc.

[0083] As can be seen, the circuit board assembly provided in this embodiment, when transferring chips to the circuit board 4, can directly align and bond the side of the growth substrate with the light-emitting chip to the weakening layer 5, and detach the light-emitting chip to be transferred from the growth substrate, so that the light-emitting chip is supported on the top wall 51 of the corresponding cavity 50. Then, pressure F is applied to the top wall 51 to break it, so that the light-emitting chip falls directly onto the corresponding chip bonding area 40. Since the distance between the side of the top wall 51 away from the circuit board 4 and the circuit board is greater than or equal to the height of the light-emitting chip, when it is necessary to continue transferring chips to other chip bonding areas on the circuit board 4, since the already transferred light-emitting chip is located in the cavity 50, it will not interfere with other chips on the growth substrate during the subsequent transfer process, thus ensuring the normal transfer of subsequent light-emitting chips. The entire chip transfer process no longer requires transferring the light-emitting chip from the growth substrate to the temporary substrate and then from the temporary substrate to the transfer substrate, and there is no longer a need to prepare temporary substrates and transfer substrates, resulting in higher transfer efficiency and lower transfer cost.

[0084] Another alternative embodiment:

[0085] For ease of understanding, this embodiment will now be described using an example manufacturing method of the aforementioned circuit board assembly. (See attached image.) Figure 5 As shown, it includes, but is not limited to:

[0086] S501: A sacrificial layer is formed on the circuit board. The sacrificial layer includes multiple sacrificial layer units that cover the bonding areas of each chip respectively, and the sacrificial layer units are separated from each other.

[0087] In this embodiment, the size and shape of each sacrificial layer unit basically determine the size and shape of the cavity subsequently formed on the circuit board. Therefore, for the setting of the shape and size of the sacrificial layer unit, please refer to the above description of the shape and size of the cavity, which will not be repeated here.

[0088] In this embodiment, the formation method and specific material of the sacrificial layer unit can be flexibly selected. For example, in some examples, the sacrificial layer unit can be, but is not limited to, a photoresist layer unit or a polyvinyl alcohol layer unit. As long as it can be removed after a weakening layer is subsequently formed on it.

[0089] S502: A weakening layer is formed on the circuit board that covers each sacrificial layer unit.

[0090] In this embodiment, the weakening layer does not completely cover each sacrificial layer unit, that is, at least one side of each sacrificial layer unit is not covered by the weakening layer, so as to serve as a clearing channel for subsequent clearing of the sacrificial layer unit.

[0091] S503: Remove each sacrificial layer unit, and the space occupied by each sacrificial layer unit forms a cavity.

[0092] For example, when photoresist is used in the sacrificial layer unit, the photoresist can be washed away to form a cavity, that is, to form a hollow structure.

[0093] For ease of understanding, the following sections will use the weakening layer as the hot melt adhesive layer and the sacrificial layer unit as the photoresist layer unit to illustrate the fabrication process. Figure 2 and Figure 3 The process of assembling the circuit board shown is illustrated as an example.

[0094] Production Figure 2 See one example of the circuit board assembly shown. Figure 6 As shown, it includes, but is not limited to:

[0095] S601: Sacrificial layer units 7 are formed on circuit board 4 to cover the bonding areas of each chip respectively.

[0096] S602: A weakening layer, i.e., a hot melt adhesive layer, is formed on the circuit board 4 to cover each sacrificial layer unit 7; in this embodiment, the weakening layer covering each sacrificial layer unit 7 is discontinuous. Fabrication Figure 4 When assembling the circuit board shown, a top wall 51 and a side wall 52 are respectively provided on the top and side surfaces of each sacrificial layer unit 7.

[0097] S603: After the weakening layer 5 is cured, each sacrificial layer unit 7 is cleaned away, and the space originally occupied by the sacrificial layer unit 7 forms a cavity 50.

[0098] Production Figure 3 See one example of the circuit board assembly shown. Figure 7 As shown, it includes, but is not limited to:

[0099] S701: Sacrificial layer units 7 are formed on circuit board 4 to cover the bonding areas of each chip respectively.

[0100] S702: A weakening layer, i.e. a hot melt adhesive layer, is formed on the circuit board 4 to cover each sacrificial layer unit 7. In this embodiment, the coverage between each sacrificial layer unit 7 is continuous, i.e., the weakening layer fills the gap between adjacent sacrificial layer units. The weakening layer is a whole hot melt adhesive layer.

[0101] S703: After the weakening layer 5 is cured, each sacrificial layer unit 7 is cleaned away, and the space originally occupied by the sacrificial layer unit 7 forms a cavity 50.

[0102] As can be seen, the circuit board assembly manufacturing method provided in this embodiment is simple, convenient, and highly efficient. When transferring the light-emitting chip to the obtained circuit board assembly, it is no longer necessary to transfer the light-emitting chip from the growth substrate to the temporary substrate and then from the temporary substrate to the transfer substrate, nor is it necessary to prepare the temporary substrate and the transfer substrate. The chip transfer efficiency is higher and the transfer cost is lower.

[0103] Another alternative embodiment:

[0104] This embodiment provides a light-emitting component, which includes the circuit board assembly shown in the above embodiments, and also includes light-emitting chips located in each chip bonding area. When these light-emitting chips are transferred to the circuit board, they are detached from the growth substrate and supported on the top wall of the corresponding area. After the top wall is broken by pressure, they fall onto the corresponding chip bonding area. The electrodes of each light-emitting chip are connected to the pads in the chip bonding area.

[0105] In one example of this embodiment, the light-emitting component can be a display panel, and the circuit board is a display backplane. The light-emitting chip can be a single-color chip, such as a blue chip, which is then combined with a corresponding light conversion layer (e.g., a quantum dot film) to produce red and green light, thereby forming a color display. In this example, the light-emitting chip can also include a first, second, and third chip emitting different colors, including red, green, and blue; for example, the first chip is a red chip emitting red light, the second chip is a blue chip emitting blue light, and the third chip is a green chip emitting green light, etc.

[0106] To facilitate understanding, the following examples of light-emitting components are provided for illustration.

[0107] See an example of a light-emitting component. Figure 8 As shown, it includes a circuit board 4, light-emitting chips 6 located on the circuit board 4 and falling into each cavity 50, and the electrodes 60 of the light-emitting chips 6 are electrically connected to the pads 41 in the corresponding chip bonding area 40. For example, the electrical connection can be achieved by welding, conductive glue, etc. Figure 8 The light-emitting component shown retains the sidewalls 52 of each cavity 50, which can serve at least one of the functions of blocking light, reflecting light, and refraction. Figure 8 In the light-emitting component shown, each side 52 is separated from the others.

[0108] See another example of a light-emitting component. Figure 9 As shown, it is similar to Figure 8 Compared to the light-emitting component shown, the main difference is that it includes a first light-emitting chip 61, a second light-emitting chip 62, and a third light-emitting chip 63, and the sidewall 52 fills the gap between adjacent chip bonding areas 40. This sidewall 52 can also serve at least one of the functions of blocking light, reflecting light, and refracting light.

[0109] See another example of a light-emitting component. Figure 10 As shown, it is similar to Figure 8 and Figure 9 Compared to the light-emitting components shown, the main difference is that after the electrodes of the light-emitting chip 6 are bonded to the corresponding pads 41, the weakening layer is removed, which means that the sidewall 52 is also removed.

[0110] The light-emitting component provided in this embodiment is made using the aforementioned circuit board assembly. During the manufacturing process, when transferring the light-emitting chip to the circuit board, it is not necessary to transfer the light-emitting chip from the growth substrate to the temporary substrate and then from the temporary substrate to the transfer substrate. It is also not necessary to prepare temporary substrates and transfer substrates. The chip transfer efficiency is higher and the transfer cost is lower, which makes the manufacturing efficiency of the light-emitting component higher and the manufacturing cost lower.

[0111] Another alternative embodiment:

[0112] For ease of understanding, this embodiment will be described below using the manufacturing method of the light-emitting component shown in the above embodiment as an example. See [link to documentation]. Figure 11 As shown, it includes, but is not limited to:

[0113] S1101: The side of the growth substrate on which the light-emitting chip is grown is aligned and bonded to the weakening layer on the circuit board. After alignment and bonding, the light-emitting chip contacts the top wall (that is, the area where the weakening layer forms the top wall).

[0114] S1102: Peel the corresponding light-emitting chip on the growth substrate from the growth substrate (for example, laser peeling can be used, but is not limited to), and remove the growth substrate. The peeled light-emitting chip is carried on the top wall; the light-emitting chip that is not peeled is removed together with the growth substrate.

[0115] S1103: Apply pressure to the top wall carrying the light-emitting chip to break it, so that the light-emitting chip carried by the top wall falls onto the corresponding chip bonding area;

[0116] S1104: Connect the electrodes of the light-emitting chip to the corresponding pads in the chip bonding area.

[0117] As can be seen, in the fabrication of light-emitting components, the side of the growth substrate with the light-emitting chip grown can be directly aligned and bonded to the weakening layer. The light-emitting chip to be transferred is then detached from the growth substrate and placed on the top wall of the corresponding cavity. Pressure is then applied to the top wall to cause it to break, allowing the light-emitting chip to fall directly onto the corresponding chip bonding area. Since the distance between the side of the top wall away from the circuit board and the circuit board is greater than or equal to the height of the light-emitting chip, when it is necessary to transfer chips to other chip bonding areas on the circuit board in the future, the already transferred light-emitting chip will not interfere with other chips on the growth substrate during the subsequent transfer process because it is located in the cavity. Therefore, the entire chip transfer process no longer requires a temporary substrate, transfer substrate, or transfer head, resulting in higher manufacturing efficiency and lower manufacturing cost.

[0118] In the field of Micro LED displays, the number of Micro LED chips transferred to the display backplane is typically in the tens of thousands or higher. Therefore, after the Micro LED chips are transferred, it is difficult to detect defects on the display backplane, and even if defects are detected, they are difficult to repair, and the repair process is complex. Furthermore, existing methods of Micro LED chip transfer involve laser peeling of the entire surface of the Micro LED chips on the growth substrate, transferring all Micro LED chips to a temporary substrate. This results in uncontrollable chip quality in the final Micro LED display device, leading to high repair costs. Additionally, because the emission wavelength of the Micro LED chips cannot be pre-selected, the final display device exhibits poor light emission uniformity. To address this issue, in this embodiment, before transferring the light-emitting chips from the growth substrate to the circuit board, for example, before aligning and bonding the side of the growth substrate with the light-emitting chips to the weakening layer on the circuit board, the following steps are also included:

[0119] Each light-emitting chip on the growth substrate is inspected, and any unqualified chips are removed from the growth substrate. This ensures that only qualified chips remain on the growth substrate, minimizing the possibility of defects in the chips transferred to the circuit board. Consequently, subsequent defect detection and repair are reduced, improving product quality and lowering maintenance costs.

[0120] In this embodiment, the detection of each light-emitting chip on the growth substrate may include, but is not limited to, at least one of the following:

[0121] Inspect the appearance of each light-emitting chip;

[0122] The optical characteristics of each light-emitting chip are tested.

[0123] For example, in one instance, mapping data can be generated in advance based on the optical characteristics and appearance quality of the light-emitting chips on the growth substrate, without being limited to Micro PL / AOI detection, thereby identifying unqualified light-emitting chips and removing them from the growth substrate.

[0124] In some examples of this embodiment, the detection of the optical characteristics of each light-emitting chip may include, but is not limited to: detecting the main wavelength of each light-emitting chip, and determining that the light-emitting chip whose main wavelength differs from the preset standard main wavelength by more than the preset difference is an unqualified light-emitting chip, thereby making the main wavelength of the light-emitting chips retained on the growth substrate more consistent, thereby improving the light emission uniformity of the light-emitting component and making its display effect or lighting effect better.

[0125] To facilitate understanding, this embodiment will be described below using an application scenario as an example. In this example, the growth substrate includes a first growth substrate, a second growth substrate, and a third growth substrate on which a first light-emitting chip (e.g., a red light-emitting chip), a second light-emitting chip (e.g., a green light-emitting chip), and a third light-emitting chip (e.g., a blue light-emitting chip) are respectively grown. In this example, aligning and bonding the side of the growth substrate on which the light-emitting chips are grown with the weakening layer on the circuit board includes:

[0126] One of the first growth substrate, the second growth substrate, and the third growth substrate is sequentially aligned and bonded to the weakening layer on the circuit board. After the light-emitting chip on the previously aligned and bonded growth substrate falls into the corresponding chip bonding area, the current growth substrate is then aligned and bonded to the weakening layer on the circuit board.

[0127] The connection between the electrodes of the light-emitting chip and the pads in the chip bonding area includes, but is not limited to, the following two methods:

[0128] Method 1: After the first, second, and third light-emitting chips are respectively placed on their corresponding chip bonding areas, the electrodes of each first, second, and third light-emitting chip are soldered to their corresponding pads in a single soldering process.

[0129] Method 2: After the light-emitting chip (e.g., the first light-emitting chip) on the previous aligned and bonded growth substrate falls to the corresponding chip bonding area, before aligning and bonding the current growth substrate with the weakening layer on the circuit board, the method further includes: soldering the electrodes (e.g., the first light-emitting chip) of each light-emitting chip that has fallen to the chip bonding area to the corresponding pads of each electrode.

[0130] The following example illustrates the process of sequentially transferring the first, second, and third light-emitting chips to the circuit board.

[0131] See the process of transferring the first light-emitting chip to the circuit board. Figure 12 As shown, it includes:

[0132] S1201: The side of the first growth substrate 81 on which the first light-emitting chip 61 is grown is aligned and bonded to the weakening layer 5 on the circuit board 4. After alignment and bonding, the area where the first light-emitting chip 61 and the weakening layer 5 form the top wall 51 is in contact.

[0133] S1202: Peel off the corresponding first light-emitting chip 61 on the first growth substrate 81 (e.g., laser peeling at 248 nm or 266 nm) and remove the first growth substrate 81. The peeled first light-emitting chip 61 is supported on the top wall 51; the unpeeled first light-emitting chip 61 is removed together with the first growth substrate 81.

[0134] S1203: Apply pressure F to the top wall 51 that carries the first light-emitting chip 61 to cause it to rupture.

[0135] S1204: After the top wall 51 breaks, the first light-emitting chip 61 carried by the top wall 51 falls onto the corresponding chip bonding area.

[0136] In this step, the electrodes of the first light-emitting chip 61 can be soldered to the pads 41 in the chip bonding area, or they can be left unsoldered and soldered together after the other light-emitting chips are transferred.

[0137] See the process of transferring the second light-emitting chip to the circuit board. Figure 13 As shown, it includes:

[0138] S1301: The side of the second growth substrate 82 where the second light-emitting chip 62 is grown is aligned and bonded to the weakening layer 5 on the circuit board 4. After alignment and bonding, the second light-emitting chip 62 contacts the area where the weakening layer 5 forms the top wall 51. In this step, the previously transferred first light-emitting chip 61 is located inside the cavity 50 and will not obstruct or interfere with the second light-emitting chip 62 on the second growth substrate 82.

[0139] S1302: Peel off the corresponding second light-emitting chip 62 on the second growth substrate 82 and remove the second growth substrate 82. The peeled second light-emitting chip 62 is supported on the top wall 51; the second light-emitting chip 62 that is not peeled off is removed together with the second growth substrate 82.

[0140] S1303: Apply pressure F to the top wall 51 that carries the second light-emitting chip 62 to cause it to rupture.

[0141] S1304: After the top wall 51 breaks, the second light-emitting chip 62 carried by the top wall 51 falls onto the corresponding chip bonding area.

[0142] In this step, the electrodes of the second light-emitting chip 62 can be soldered to the pads 41 in the chip bonding area, or they can be left unsoldered and soldered together after the other light-emitting chips are transferred.

[0143] See the process of transferring the third light-emitting chip to the circuit board. Figure 14 As shown, it includes:

[0144] S1401: The side of the third growth substrate 83 where the third light-emitting chip 63 is grown is aligned and bonded to the weakening layer 5 on the circuit board 4. After alignment and bonding, the third light-emitting chip 63 and the weakening layer 5 form contact in the area where the top wall 51 is formed. In this step, the previously transferred first light-emitting chip 61 and second light-emitting chip 62 are located in their respective cavities 50, and will not obstruct or interfere with the third light-emitting chip 63 on the third growth substrate 83.

[0145] S1402: Peel off the corresponding third light-emitting chip 63 on the third growth substrate 83 and remove the third growth substrate 83. The peeled third light-emitting chip 63 is supported on the top wall 51; the third light-emitting chip 63 that is not peeled off is removed together with the third growth substrate 83.

[0146] S1403: Apply pressure F to the top wall 51 that carries the third light-emitting chip 63 to cause it to rupture.

[0147] S1404: After the top wall 51 breaks, the third light-emitting chip 63 carried by the top wall 51 falls onto the corresponding chip bonding area.

[0148] In this step, the electrodes of the first light-emitting chip 61, the second light-emitting chip 62, and the third light-emitting chip 63 can be soldered to the pads 41 in the chip bonding area in one go, thereby improving the soldering efficiency and soldering effect.

[0149] As can be seen, in the above chip transfer process, it is not necessary to transfer the light-emitting chip from the growth substrate to the temporary substrate and then from the temporary substrate to the transfer substrate. There is also no need to prepare temporary substrates and transfer substrates. The chip transfer efficiency is higher and the transfer cost is lower, which makes the manufacturing efficiency of the light-emitting component higher and the manufacturing cost lower.

[0150] This embodiment also provides a display screen, which can be a flexible display screen or a rigid display screen, and can be a regular-shaped display screen, such as rectangular, circular, or elliptical, or an irregularly shaped display screen. The display screen includes a display screen frame and a display panel as shown in the examples above. The display panel is made of the aforementioned light-emitting components and is fixed within the display screen frame. It should be understood that the display screen in this embodiment can be applied to various electronic devices, such as monitors, computers, mobile phones, smartwatches, in-vehicle devices, billboards, etc. This display screen has higher manufacturing efficiency, lower cost, better yield, higher light emission efficiency, and better display effect.

[0151] It should be understood that the application of the present invention is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A circuit board assembly, characterized in that, include: A circuit board having multiple chip bonding areas, each chip bonding area containing pads corresponding to the electrodes of a light-emitting chip, wherein: The circuit board assembly also includes a weakening layer disposed on the circuit board and having multiple cavities formed thereon; The plurality of cavities are isolated from each other by the weakening layer, and one chip bonding area corresponds to one cavity. The weakening layer forms the sidewall and top wall of each cavity. The top wall is used to support the light-emitting chip detached from the growth substrate, and to break under pressure so that the supported light-emitting chip falls onto the corresponding chip bonding area; the distance between the side of the top wall away from the circuit board and the circuit board is greater than or equal to the height of the light-emitting chip.

2. The circuit board assembly as claimed in claim 1, characterized in that, The weakening layer is a hot melt adhesive layer.

3. The circuit board assembly as described in claim 2, characterized in that, The hot melt adhesive layer is viscous.

4. The circuit board assembly as described in any one of claims 1-3, characterized in that, The thickness of the top wall is less than or equal to 5 micrometers.

5. A light-emitting component, characterized in that, include: The circuit board assembly as described in any one of claims 1-4; The light-emitting chip is located in each of the chip bonding areas. After the light-emitting chip is detached from the growth substrate, it is supported by the top wall. After the top wall is broken by pressure, it falls onto the corresponding chip bonding area. The electrodes of the light-emitting chip are connected to the pads in the chip bonding area.

6. The light-emitting component as described in claim 5, characterized in that, The circuit board is a display back panel, and the light-emitting chip includes a first light-emitting chip, a second light-emitting chip, and a third light-emitting chip with different light-emitting colors, including red, green, and blue.

7. A method for manufacturing a circuit board assembly as described in any one of claims 1-4, characterized in that, include: A sacrificial layer is formed on the circuit board. The sacrificial layer includes a plurality of sacrificial layer units that cover each of the chip bonding regions, and the sacrificial layer units are separated from each other. A weakening layer is formed on the circuit board to cover each of the sacrificial layer units; The space occupied by each sacrificial layer unit is removed to form the cavity.

8. A method for manufacturing a light-emitting component as described in claim 5 or 6, characterized in that, include: The side of the growth substrate on which the light-emitting chip is grown is aligned and bonded to the weakening layer on the circuit board. After alignment and bonding, the light-emitting chip contacts the top wall. The corresponding light-emitting chip on the growth substrate is peeled off from the growth substrate, and the growth substrate is removed. The peeled-off light-emitting chip is carried on the top wall. Pressure is applied to the top wall carrying the light-emitting chip to cause it to break, so that the light-emitting chip carried by the top wall falls onto the corresponding chip bonding area; Connect the electrodes of the light-emitting chip to the corresponding pads in the chip bonding area.

9. The method for manufacturing a light-emitting component as described in claim 8, characterized in that, Before aligning and bonding the side of the growth substrate where the light-emitting chip is grown with the weakening layer on the circuit board, the process further includes: Each of the light-emitting chips on the growth substrate is inspected; Remove the light-emitting chip that fails the test from the growth substrate; The detection of each of the light-emitting chips on the growth substrate includes at least one of the following: The appearance of each of the light-emitting chips is inspected; The optical characteristics of each of the light-emitting chips are tested.

10. The method for manufacturing a light-emitting component as described in claim 8 or 9, characterized in that, The growth substrate includes a first growth substrate, a second growth substrate, and a third growth substrate on which a first light-emitting chip, a second light-emitting chip, and a third light-emitting chip are respectively grown. The first light-emitting chip, the second light-emitting chip, and the third light-emitting chip emit different colors, including red, green, and blue. The step of aligning and bonding the side of the growth substrate where the light-emitting chip is grown with the weakening layer on the circuit board includes: One of the first growth substrate, the second growth substrate, and the third growth substrate is sequentially aligned and bonded to the weakening layer on the circuit board. After the light-emitting chip on the previously aligned and bonded growth substrate falls into the corresponding chip bonding area, the current growth substrate is then aligned and bonded to the weakening layer on the circuit board.

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