A circuit board assembly and chip transfer method

Abstract

The present application relates to a kind of circuit board assembly and chip transfer method, circuit board assembly includes circuit board and support layer, circuit board is equipped with multiple chip bonding area, chip bonding area is equipped with pad corresponding with the electrode of light-emitting chip in;Support layer includes the support unit respectively in each chip bonding area, adjacent support unit is separated from each other;Support unit is used to carry light-emitting chip, and after being heated, it changes from solid to liquid, so that its carrying light-emitting chip falls in the chip bonding area where it is located.Due to the support layer with specific heat melting performance on the circuit board, the support layer can be used to temporarily adhere light-emitting chip at a certain height, while light-emitting chip falls on the pad of circuit board with the support layer heated and melted;It is beneficial to guarantee the consistency of chip angle when light-emitting chip is transferred from the carrying substrate to the circuit board, so as to effectively avoid the problem of deviation when chip is transferred.

Description

Technical Field

[0001] This invention relates to the field of display technology, and more particularly to a circuit board assembly and a chip transfer method. Background Technology

[0002] Currently, in the manufacturing process of display panels, red, green, and blue light-emitting chips need to be transferred sequentially from their respective carrier substrates to a circuit board. During chip transfer, to prevent chips already transferred to the circuit board from obstructing the transfer of subsequent chips, an appropriate gap needs to be maintained between the carrier substrate and the circuit board. Because a relatively large gap must be maintained between the carrier substrate and the circuit board, misalignment can easily occur during the process of the light-emitting chips being peeled off the carrier substrate and falling onto the circuit board.

[0003] Therefore, how to prevent the light-emitting chip from shifting during the transfer process from the carrier substrate to the circuit board is an urgent problem to be solved. Summary of the Invention

[0004] In view of the shortcomings of the above-mentioned related technologies, the purpose of this application is to provide a circuit board assembly and a chip transfer method, which aims to solve the technical problem of misalignment that occurs during the transfer of light-emitting chips from a carrier substrate to a circuit board in the prior art.

[0005] This application provides a circuit board assembly, including:

[0006] A circuit board having multiple chip bonding areas, each chip bonding area having pads corresponding to the electrodes of a light-emitting chip;

[0007] The support layer includes support units respectively disposed in each of the chip bonding areas, and adjacent support units are separated from each other; the support unit is used to support the light-emitting chip, and changes from solid to liquid after being heated, so that the light-emitting chip it supports falls into the chip bonding area where it is located.

[0008] The aforementioned circuit board assembly features a support layer with specific heat-melting properties. This support layer can be used to temporarily adhere the light-emitting chip at a certain height, making the distance between the light-emitting chip and the support layer on the circuit board during chip transfer less than the distance between the light-emitting chip and the pads on the circuit board in the prior art. Simultaneously, the light-emitting chip falls onto the pads on the circuit board as the support layer melts due to heat. This helps ensure the consistency of the chip angle when the light-emitting chip is transferred from the support substrate to the circuit board, thereby effectively avoiding the problem of chip misalignment during transfer.

[0009] Optionally, the support unit includes at least two support pillars distributed within the chip bonding area, with adjacent support pillars separated from each other.

[0010] Optionally, the support pillar includes a first support pillar disposed on the pad within the chip bonding area.

[0011] Optionally, the support pillar further includes a second support pillar disposed between the pads within the chip bonding area.

[0012] Optionally, at least one of the first support column and the second support column includes a plurality of sub-support columns, with adjacent sub-support columns separated from each other.

[0013] Optionally, the support pillar includes a third support pillar disposed within the chip bonding area; the third support pillar is located in the area outside the area where the solder pad is located within the chip bonding area.

[0014] Optionally, the support layer further includes a fourth support pillar disposed between adjacent chip bonding areas.

[0015] Optionally, the height of the support column is greater than the sum of the height of the light-emitting chip and the height of the pad.

[0016] Optionally, the support layer is a thermoplastic resin layer.

[0017] Based on the same inventive concept, this application also provides a chip transfer method, the method being used to transfer a chip from the circuit board assembly described above, comprising:

[0018] This includes transferring light-emitting chips to circuit board assemblies as described above;

[0019] The process of transferring the light-emitting chip to the circuit board assembly includes:

[0020] The support layer is disposed on the side of the carrier substrate on which the light-emitting chip is carried;

[0021] The target light-emitting chip to be transferred on the carrier substrate is peeled off from the carrier substrate, the peeled target light-emitting chip is carried on the support layer, and the carrier substrate is removed.

[0022] The target area of ​​the support layer carrying the target light-emitting chip is heated to change it from a solid state to a liquid state, so that the target light-emitting chip falls into the chip bonding area where the target area is located;

[0023] The corresponding pads are heated so that the target light-emitting chip is soldered onto the circuit board.

[0024] The chip transfer method described above involves first transferring the target light-emitting chip to the support layer of the circuit board, and then the light-emitting chip melts as the support layer is heated and falls onto the pads of the circuit board. This helps to ensure the consistency of the chip angle when the light-emitting chip is transferred from the carrier substrate to the circuit board, thereby effectively avoiding the problem of chip misalignment during transfer. Attached Figure Description

[0025] Figure 1 This is a flowchart illustrating an existing chip transfer method.

[0026] Figure 2-1 This is a schematic diagram of the circuit board assembly in an embodiment of the present invention. Figure 1 Top view;

[0027] Figure 2-2 This is a schematic diagram of the circuit board assembly in an embodiment of the present invention. Figure 1 A sectional view;

[0028] Figure 3 This is a second schematic diagram of the circuit board assembly in an embodiment of the present invention;

[0029] Figure 4 This is a schematic diagram of the circuit board assembly in an embodiment of the present invention. Figure 3 ;

[0030] Figure 5 This is a schematic diagram of the circuit board assembly in an embodiment of the present invention. Figure 4 ;

[0031] Figure 6 This is a schematic diagram of the circuit board assembly in an embodiment of the present invention. Figure 5 ;

[0032] Figure 7 This is a schematic diagram of the circuit board assembly in an embodiment of the present invention. Figure 6 ;

[0033] Figure 8 This is a schematic diagram of the circuit board assembly in an embodiment of the present invention. Figure 7 ;

[0034] Figure 9 This is a schematic diagram of the circuit board assembly in an embodiment of the present invention. Figure 8 ;

[0035] Figure 10 This is a schematic diagram of the method for transferring light-emitting chips to a circuit board assembly in an embodiment of the present invention;

[0036] Figure 11 This is a schematic diagram illustrating the process of transferring the light-emitting chip to the circuit board assembly in an embodiment of the present invention;

[0037] 11-First carrier substrate; 12-Second carrier substrate; 13-Third carrier substrate; 21-Red light-emitting chip; 22-Green light-emitting chip; 23-Blue light-emitting chip; 3-Circuit board; 31-Chip bonding area; 301-Pad; 302-Support unit; 3021-First support post; 3022-Second support post; 3023-Third support post; 3024-Fourth support post. Detailed Implementation

[0038] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings. Preferred embodiments of this application are shown in the drawings. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this application.

[0039] 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 application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application.

[0040] Micro LED (Micro Light Emitting Diode Display) is a next-generation display technology. Compared to existing LCD displays, it offers higher photoelectric efficiency, higher brightness, higher contrast, and lower power consumption, and can also be combined with flexible panels to achieve flexible displays.

[0041] A Micro LED display panel comprises several pixel areas, each containing a red, blue, and green light-emitting chip. During the panel's fabrication, these chips need to be transferred from their respective substrates to a circuit board. Please refer to [link to relevant documentation]. Figure 1 , Figure 1 This is a flowchart illustrating an existing chip transfer method, which includes the following steps:

[0042] S101: A first carrier substrate 11 is provided, on which a plurality of red light-emitting chips 21 are carried. The red light-emitting chips 21 to be transferred are selectively peeled off from the first carrier substrate 11 using a laser.

[0043] S102: A second carrier substrate 12 is provided, on which a plurality of green light-emitting chips 22 are carried. To prevent the red light-emitting chips 21, already transferred to the circuit board, from obstructing the transfer of the green light-emitting chips 22, a distance d1 needs to be maintained between the second carrier substrate 12 and the circuit board. This distance d1 is greater than the sum of the height of the red light-emitting chips 21, the height of the green light-emitting chips 22, and the height of the pads on the circuit board. The green light-emitting chips 22 to be transferred are selectively peeled off from the second carrier substrate 12 using a laser.

[0044] S103: A third carrier substrate 13 is provided, on which a plurality of blue light-emitting chips 23 are carried. The third carrier substrate 13 needs to maintain a distance d2 between itself and the circuit board. The distance d2 is greater than the sum of the height of the larger of the red light-emitting chip 21 and the green light-emitting chip 22, the height of the blue light-emitting chip 23, and the height of the pads on the circuit board. The blue light-emitting chips 23 to be transferred are selectively peeled off from the third carrier substrate 13 using a laser.

[0045] When a large gap must be maintained between the carrier substrate and the circuit board, the chip is prone to misalignment during the process of being peeled off the carrier substrate and falling onto the circuit board.

[0046] Therefore, this application aims to provide a solution that can solve the above-mentioned technical problems, the details of which will be described in subsequent embodiments.

[0047] Embodiments of the present invention

[0048] Please see Figures 2-1 to 2-2 , Figures 2-1 to 2-2 This is a schematic diagram of the circuit board assembly in an embodiment of the present invention. Figure 1 The circuit board assembly includes, but is not limited to:

[0049] Circuit board 3, circuit board 3 is provided with multiple chip bonding areas 31, and chip bonding areas 31 are provided with pads 301 corresponding to the electrodes of the light-emitting chip.

[0050] The support layer includes support units 302 respectively disposed in each chip bonding area 31, and adjacent support units 302 are separated from each other; the support unit 302 is used to support the light-emitting chip, and changes from solid to liquid after being heated, so that the light-emitting chip it supports falls into the chip bonding area 31 where it is located.

[0051] The aforementioned circuit board assembly features a support layer with specific heat-melting properties. This support layer can be used to temporarily adhere the light-emitting chip at a certain height, making the distance between the light-emitting chip and the support layer on the circuit board during chip transfer less than the distance between the light-emitting chip and the pads on the circuit board in the prior art. Simultaneously, the light-emitting chip falls onto the pads on the circuit board as the support layer melts due to heat. This helps ensure the consistency of the chip angle when the light-emitting chip is transferred from the support substrate to the circuit board, thereby effectively avoiding the problem of chip misalignment during transfer.

[0052] In this embodiment of the invention, the structure of the support layer and the area of ​​the support layer on the circuit board can be flexibly set according to actual needs. For ease of understanding, the structure of the support layer is further described below through some embodiments:

[0053] In some embodiments, the support layer may be located only within the chip bonding region 31. The support layer includes support units 302 respectively disposed within each chip bonding region 31, with adjacent support units 302 separated from each other. Each support unit 302 includes at least two support pillars distributed within the chip bonding region 31, with adjacent support pillars separated from each other. The present invention can also flexibly set the number of support pillars and their area within the chip bonding region 31. Depending on the different areas of the support pillars within the chip bonding region 31, it can be divided into, but is not limited to, first support pillars 3021, second support pillars 3022, and third support pillars 3023. The support unit 302 may include one or more of the first support pillar 3021, second support pillar 3022, or third support pillar 3023. Further explanation is provided below through some examples:

[0054] As an example, please see Figure 3 , Figure 3 The second schematic diagram of the circuit board assembly in this embodiment of the invention shows that the support pillars include a first support pillar 3021 disposed on the pad 301 within the chip bonding area 31. In this case, the support unit 302 includes two first support pillars 3021. The first support pillars 3021 may fully or partially cover the end face of the pad 301 away from the end of the circuit board 3.

[0055] As another example, see Figure 4 , Figure 4 This is a schematic diagram of the circuit board assembly in an embodiment of the present invention. Figure 3 The support pillars include second support pillars 3022 disposed between pads 301 within the chip bonding area 31. In this case, the support unit 302 includes two first support pillars 3021 and one second support pillar 3022.

[0056] At least one of the first support column 3021 and the second support column 3022 includes a plurality of sub-support columns, with adjacent sub-support columns being separated from each other. That is, the first support column 3021 and / or the second support column 3022 can be composed of a plurality of separate sub-support columns. See also... Figure 5 , Figure 5 This is a schematic diagram of the circuit board assembly in an embodiment of the present invention. Figure 4 The first support column 3021 and the second support column 3022 are both multiple sub-support columns arranged at intervals.

[0057] As another example, see Figure 6 , Figure 6 This is a schematic diagram of the circuit board assembly in an embodiment of the present invention. Figure 5 The support pillar includes a third support pillar 3023 disposed within the chip bonding area; the third support pillar 3023 is located in the area outside the area where the solder pads are located within the chip bonding area. In this case, the support unit 302 includes two third support pillars 3023. Each third support pillar 3023 may include multiple sub-support pillars, with adjacent sub-support pillars separated from each other.

[0058] In some embodiments, the support layer can be located both within the chip bonding area 31 on the circuit board and in areas other than the chip bonding area 31 on the circuit board. In this case, the support layer includes support units 302 respectively disposed within each chip bonding area 31, and support pillars disposed in the non-chip bonding areas. The support units 302 disposed within each chip bonding area 31 have been described above and will not be repeated here. The present invention can also flexibly configure the number and structure of support pillars in the non-chip bonding areas, which will be further illustrated below with some examples:

[0059] The support layer also includes fourth support pillars 3034 disposed between adjacent chip bonding regions. In some examples, a fourth support pillar 3034 is provided between each adjacent chip bonding region. See also Figure 7 , Figure 7 This is a schematic diagram of the circuit board assembly in an embodiment of the present invention. Figure 6 Support pillars are provided within each chip bonding area and between adjacent chip bonding areas on the circuit board. In some other examples, a fourth support pillar 3034 is provided between some adjacent chip bonding areas. Please refer to [link to relevant documentation]. Figure 8 , Figure 8 This is a schematic diagram of the circuit board assembly in an embodiment of the present invention. Figure 7 Each chip bonding area on the circuit board is provided with a support pillar, and some adjacent chip bonding areas are also provided with support pillars.

[0060] The aforementioned fourth support column 3034 may include multiple sub-support columns, with adjacent sub-support columns being separate from each other. That is, the fourth support column 3034 can be composed of multiple separate sub-support columns. Please refer to [link / reference]. Figure 9 , Figure 9 This is a schematic diagram of the circuit board assembly in an embodiment of the present invention. Figure 8 The fourth support column 3034 consists of multiple sub-support columns arranged at intervals.

[0061] In this embodiment of the invention, the height of the support pillars on the circuit board can be flexibly set according to actual application requirements. The height of the support pillar can be understood as the distance between the end face of the support pillar furthest from the circuit board and the end face of the circuit board. To ensure that the support pillars within the support unit can be used to support the light-emitting chips, the height of the support pillars is greater than the height of the pads. When it is necessary to transfer light-emitting chips of different colors to the circuit board, to prevent the light-emitting chips already transferred to the circuit board from obstructing the transfer of subsequent light-emitting chips, the height of the support pillars can be set to be greater than the sum of the height of the light-emitting chips and the height of the pads. If the heights of the light-emitting chips of different colors are not the same, the height of the support pillars can be set to the sum of the maximum height of the light-emitting chips and the height of the pads. For example, the light-emitting chips of different colors include, but are not limited to, red, green, and blue light-emitting chips; in this case, the maximum height of the light-emitting chips is the maximum height among the red, green, and blue light-emitting chips.

[0062] In practical applications, considering that the chip angle will not change within a certain distance after the light-emitting chip is peeled from the carrier substrate, when transferring the light-emitting chip to the circuit board assembly, the side of the carrier substrate carrying the light-emitting chip can be positioned opposite the support layer on the circuit board. That is, the side of the carrier substrate carrying the light-emitting chip can contact the support layer on the circuit board, or maintain a certain distance to ensure that the light-emitting chip does not shift when falling this distance. In this case, the height of the support pillar can also be less than the sum of the height of the light-emitting chip and the height of the pad.

[0063] Furthermore, in practical applications, considering that the carrier substrate carrying the light-emitting chip may warp, in order to prevent the carrier substrate from contacting the circuit board during chip transfer, it is necessary to control the distance between the end face of the carrier substrate carrying the light-emitting chip and the end face of the circuit board with the pad to be no less than a preset value. If, due to the limitations of existing conditions, this preset value is much greater than the sum of the height of the two light-emitting chips and the height of the pad, the height of the support column can be set to be no less than this preset value minus the difference between the height of one light-emitting chip and the height of the pad.

[0064] In this embodiment of the invention, the support layer is a thermoplastic resin layer. The thermoplastic resin layer is solid at room temperature and becomes liquid when heated. When the thermoplastic resin layer changes from solid to liquid upon heating, it tends to flow under the gravity of the light-emitting chip it supports, thereby allowing the light-emitting chip to fall into its chip bonding area. The material of the thermoplastic resin layer includes, but is not limited to, polyurethane or polysiloxane.

[0065] This invention also provides a chip transfer method for transferring chips from the circuit board assembly described above. Please refer to... Figure 10 , Figure 10 This is a schematic flowchart illustrating a method for transferring a light-emitting chip to a circuit board assembly according to an embodiment of the present invention. The chip transfer method includes, but is not limited to, the following steps:

[0066] S201: A support layer is provided on the side of the substrate that carries the light-emitting chip, facing the circuit board.

[0067] S202: The target light-emitting chip to be transferred on the carrier substrate is peeled off from the carrier substrate. The peeled target light-emitting chip is carried on the support layer, and the carrier substrate is removed.

[0068] S203: The target area on which the target light-emitting chip is supported by the support layer is heated to change it from solid to liquid, so that the target light-emitting chip falls into the chip bonding area where the target area is located;

[0069] S204: Heat the corresponding pads to solder the target light-emitting chip onto the circuit board.

[0070] The chip transfer method described above involves first transferring the target light-emitting chip to the support layer of the circuit board, and then the light-emitting chip melts as the support layer is heated and falls onto the pads of the circuit board. This helps to ensure the consistency of the chip angle when the light-emitting chip is transferred from the carrier substrate to the circuit board, thereby effectively avoiding the problem of chip misalignment during transfer.

[0071] In embodiments of the present invention, the carrier substrate includes, but is not limited to, a carrier substrate, a transient substrate (or temporary substrate) or a transfer substrate during mass transfer.

[0072] In the field of Micro LED displays, the number of Micro LED chips transferred onto circuit boards 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 circuit board, and even if defects are detected, they are difficult to repair, and the repair process is complex. Furthermore, while existing methods selectively laser-peel the Micro LED chips on the carrier substrate during Micro LED chip transfer, the inability to distinguish between good and bad chips results in uncontrollable chip quality in the final Micro LED display device, leading to high repair costs. Additionally, the inability to pre-select the emission wavelength of the Micro LED chips results in poor light uniformity in the final display device. To address this issue, this embodiment includes the following step: Before transferring the light-emitting chips from the carrier substrate to the circuit board, for example, before setting the support layer on the side of the carrier substrate carrying the light-emitting chips onto the circuit board:

[0073] Each light-emitting chip on the carrier substrate is inspected, and any unqualified chips are removed from the carrier substrate. This ensures that only qualified chips remain on the carrier substrate, minimizing the possibility of defects in the chips transferred to the circuit board. Consequently, it reduces the need for subsequent defect detection and repair, improves product quality, and lowers maintenance costs.

[0074] In this embodiment, the detection of each light-emitting chip on the carrier substrate may include, but is not limited to, at least one of the following:

[0075] Inspect the appearance of each light-emitting chip;

[0076] The optical characteristics of each light-emitting chip are tested.

[0077] For example, in one instance, by first assessing the optical characteristics and appearance quality of the light-emitting chips on the carrier substrate using methods not limited to Micro PL / AOI inspection, corresponding mapping data can be generated in advance, thereby identifying unqualified light-emitting chips and removing them from the carrier substrate.

[0078] 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 carrier substrate more consistent, thereby improving the light emission uniformity of the light-emitting component and making its display effect or lighting effect better.

[0079] For ease of understanding, this embodiment will be described below using an application scenario as an example. In this example, the carrier substrate includes a first carrier substrate, a second carrier substrate, and a third carrier substrate, which respectively carry 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). In this example, the support layer on the side of the carrier substrate carrying the light-emitting chips facing the circuit board includes:

[0080] The light-emitting chip on one of the first carrier substrate, the second carrier substrate, and the third carrier substrate is sequentially aligned and bonded to the support layer on the circuit board. After the target light-emitting chip on the previous aligned and bonded carrier substrate falls into the chip bonding area where the target area is located, the light-emitting chip on the current carrier substrate is aligned and bonded to the support layer on the circuit board.

[0081] or,

[0082] The light-emitting chips on one of the first, second, and third carrier substrates are sequentially aligned with the support layer on the circuit board at a preset distance. After the target light-emitting chip on the previously aligned carrier substrate falls into the chip bonding area where the target region is located, the light-emitting chip on the current carrier substrate is then aligned with the support layer on the circuit board at the preset distance. It is understood that after the target light-emitting chip is peeled from the carrier substrate, its angle remains consistent as it falls at this preset distance, preventing chip skew.

[0083] When heating the target area on the support layer that carries the target light-emitting chip to change it from a solid to a liquid state, the target area can be heated by laser irradiation on the side of the circuit board that carries the target light-emitting chip; alternatively, the target area can be heated by laser irradiation on the side of the circuit board that is away from the side that carries the target light-emitting chip.

[0084] In this example, the corresponding pads are heated to solder the target light-emitting chip onto the circuit board, including but not limited to the following two methods:

[0085] 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.

[0086] Method 2: After the light-emitting chip (e.g., the first light-emitting chip) on the previous aligned carrier substrate falls to the corresponding chip bonding area, before aligning the light-emitting chip on the current carrier substrate with the support layer on the circuit board, the method further includes: soldering the electrodes (e.g., the first light-emitting chip) of each light-emitting chip currently falling to the chip bonding area to the corresponding pads of each electrode.

[0087] Please see Figure 11 , Figure 11 This is a schematic diagram of the process of transferring light-emitting chips to a circuit board assembly in an embodiment of the present invention. The following description uses the process of sequentially transferring red light-emitting chips, green light-emitting chips, and blue light-emitting chips to the circuit board as an example.

[0088] S301: Align and bond the side of the first carrier substrate 11 that carries the red light-emitting chip 21 with the support layer on the circuit board 3.

[0089] S302: The red light-emitting chip 21 to be transferred on the first carrier substrate 11 is peeled off from the first carrier substrate 11 (for example, by selective peeling with laser at 248 nm or 266 nm), and the first carrier substrate 11 is removed; the peeled red light-emitting chip is carried on the support layer; the red light-emitting chip 21 that has not been peeled off is removed together with the carrier substrate 11.

[0090] S303: The target area on which the red light-emitting chip 21 is supported is heated to change it from solid to liquid (e.g., by irradiation with a 1064 nm laser), so that the red light-emitting chip 21 falls into the chip bonding area where the target area is located.

[0091] In this step, the electrodes of the red light-emitting chip 21 can be soldered to the pads in the chip bonding area, or they can be left unsoldered and soldered together after the other light-emitting chips are transferred.

[0092] S304: Align and bond the side of the second carrier substrate 12 that carries the green light-emitting chip 22 with the support layer on the circuit board 3.

[0093] S305: The green light-emitting chip 22 to be transferred on the second carrier substrate 12 is peeled off from the second carrier substrate 12 (for example, by selective laser peeling at 248 nm or 266 nm), and the second carrier substrate 12 is removed; the peeled green light-emitting chip 22 is supported on the support layer; the green light-emitting chip 22 that has not been peeled off is removed together with the second carrier substrate 12.

[0094] S306: The target area on which the green light-emitting chip 22 is supported is heated to change it from solid to liquid (e.g., by irradiation with a 1064 nm laser), so that the green light-emitting chip 22 falls into the chip bonding area where the target area is located.

[0095] In this step, the electrodes of the green light-emitting chip 22 can be soldered to the pads in the chip bonding area, or they can be left unsoldered and soldered together after the other light-emitting chips are transferred.

[0096] S307: The side of the third carrier substrate 13 that carries the blue light-emitting chip 23 is aligned and bonded to the support layer on the circuit board 3.

[0097] S308: The blue light-emitting chip 23 to be transferred on the third carrier substrate 13 is peeled off from the third carrier substrate 13 (for example, by selective laser peeling at 248 nm or 266 nm), and the third carrier substrate 13 is removed; the peeled blue light-emitting chip 23 is supported on the support layer; the blue light-emitting chip 23 that is not peeled off is removed together with the third carrier substrate 13.

[0098] S309: The target area on which the blue light-emitting chip 23 is supported is heated to change it from solid to liquid (e.g., by irradiation with a 1064 nm laser), so that the blue light-emitting chip 23 falls into the chip bonding area where the target area is located.

[0099] In this step, the electrodes of the red light-emitting chip 21, the green light-emitting chip 22, and the blue light-emitting chip 23 can be soldered to the pads in the chip bonding area in one go, thereby improving the soldering efficiency and soldering effect.

[0100] 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 having pads corresponding to the electrodes of a light-emitting chip; A support layer includes support units disposed in each of the chip bonding areas, with adjacent support units separated from each other; the support unit is used to support the light-emitting chip and changes from solid to liquid after being heated, so that the light-emitting chip it supports falls into the chip bonding area where it is located; The support unit includes at least two support pillars distributed within the chip bonding area, with adjacent support pillars separated from each other; The support pillar includes a first support pillar disposed on the pad within the chip bonding area; The support pillar also includes a second support pillar disposed between the pads within the chip bonding area.

2. The circuit board assembly as claimed in claim 1, characterized in that, At least one of the first support column and the second support column includes a plurality of sub-support columns, with adjacent sub-support columns separated from each other.

3. The circuit board assembly as claimed in claim 1, characterized in that, The support pillar includes a third support pillar disposed within the chip bonding area; the third support pillar is located in the area outside the area where the solder pad is located within the chip bonding area.

4. The circuit board assembly as described in any one of claims 1-3, characterized in that, The support layer also includes a fourth support pillar disposed between adjacent chip bonding areas.

5. The circuit board assembly as described in any one of claims 1-3, characterized in that, The height of the support column is greater than the sum of the height of the light-emitting chip and the height of the pad.

6. The circuit board assembly as described in any one of claims 1-3, characterized in that, The support layer is a thermoplastic resin layer.

7. A chip transfer method, said method being used to transfer a light-emitting chip to a circuit board assembly as described in any one of claims 1-6, characterized in that, include; A support layer is disposed on the side of the substrate on which the light-emitting chip is carried; The target light-emitting chip to be transferred on the carrier substrate is peeled off from the carrier substrate, the peeled target light-emitting chip is carried on the support layer, and the carrier substrate is removed. The target area of ​​the support layer carrying the target light-emitting chip is heated to change it from solid to liquid, so that the target light-emitting chip falls into the chip bonding area where the target area is located; The corresponding pads are heated so that the target light-emitting chip is soldered onto the circuit board.

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