Display module and manufacturing method thereof

Abstract

The present application provides a display module and a method for preparing the same. The display module includes a display module, a circuit board, and a conductive adhesive layer. The circuit board includes a first outer circuit layer, a first insulating adhesive layer, a support sheet, a second insulating adhesive layer, and a second outer circuit layer stacked in sequence. An opening is provided in the support sheet, and the second insulating adhesive layer is also filled in the opening to form a filling adhesive portion. A first blind hole is also provided in the circuit board, sequentially passing through the second insulating adhesive layer, the filling adhesive portion, and the first insulating adhesive layer. The bottom of the first blind hole corresponds to the first outer circuit layer. A first conductive portion is provided in the first blind hole, and the first outer circuit layer and the second outer circuit layer are electrically connected at least through the first conductive portion. The conductive adhesive layer is used to bond the display module to the first outer circuit layer.

Description

Technical Field

[0001] The present application relates to the field of display, and in particular to a display module and a method for preparing the same. Background Art

[0002] TFT display modules are the mainstream display devices for electronic products such as laptops and desktops. Each liquid crystal pixel in this type of display module is driven by a thin-film transistor (TFT) integrated behind the pixel, powered by a driver chip. However, if the display module requires additional electronic components, the only option is to place anisotropic conductive adhesive (ACF) on the back of the TFT and then mount the electronic components on top of the ACF. This mounting method significantly limits process flexibility.

[0003] To increase process flexibility, a circuit board can be laminated onto the display module. Electronic components can then be mounted on the circuit board using mainstream placement techniques, allowing the circuit board to serve as a bridge between the display module's thin-film transistors and the electronic components. However, uneven pressure during lamination not only results in an uneven surface finish, but also makes it difficult to ensure proper electrical continuity between the display module and the circuit board. Summary of the Invention

[0004] In view of the above, it is necessary to propose a display module and a manufacturing method thereof.

[0005] The present application provides a method for preparing a display module, comprising the following steps: providing a circuit board, the circuit board comprising a first outer circuit layer, a first insulating adhesive layer, a support sheet, a second insulating adhesive layer, and a second outer circuit layer stacked in sequence, the support sheet being provided with an opening, the second insulating adhesive layer further filling the opening to form a filling adhesive portion, the circuit board further being provided with a first blind hole sequentially penetrating the second insulating adhesive layer, the filling adhesive portion, and the first insulating adhesive layer, the bottom of the first blind hole corresponding to the first outer circuit layer, the first blind hole being provided with a first conductive portion, the first outer circuit layer and the second outer circuit layer being electrically connected at least via the first conductive portion; and sequentially laminating a conductive adhesive layer and a display module on the first outer circuit layer, the conductive adhesive layer being made of a conductive resin, the conductive resin being electrically conductive along the thickness direction of the circuit board and electrically insulated along an extension plane of the circuit board, so that the display module is bonded to the first outer circuit layer through the conductive adhesive layer, thereby manufacturing the display module.

[0006] In some possible implementations, an isolation layer is further provided in the first insulating adhesive layer, and the isolation layer is made of polyimide or glass fiber.

[0007] In some possible implementations, the circuit board further includes a first dielectric layer and an intermediate circuit layer disposed between the second insulating adhesive layer and the second outer circuit layer, the first blind hole also passes through the intermediate circuit layer and the first dielectric layer, and the intermediate circuit layer is electrically connected to the first outer circuit layer through the first conductive portion.

[0008] In some possible implementations, the method for preparing the circuit board includes the following steps: providing a copper foil substrate, the copper foil substrate including a first copper foil layer; etching the first copper foil layer into the first outer circuit layer; sequentially pressing the first insulating adhesive layer and the support sheet on the first outer circuit layer; opening the opening in the support sheet; sequentially pressing the second insulating adhesive layer, the first dielectric layer and the third copper foil layer on the support sheet having the opening; opening the first blind hole that sequentially passes through the third copper foil layer, the first dielectric layer, the second insulating adhesive layer, the filling adhesive portion and the first insulating adhesive layer, and electroplating the first conductive portion in the first blind hole; and forming the second outer circuit layer on the intermediate circuit layer through a build-up process.

[0009] In some possible implementations, the pressing includes: providing a pressing jig, the pressing jig including an upper mold and a lower mold, the upper mold and the lower mold being arranged relative to each other and surrounding to form a receiving cavity; placing an intermediate formed by stacking the display module, the conductive adhesive layer and the circuit board in sequence in the receiving cavity, and making the display module and the second outer circuit layer face the upper mold and the lower mold respectively; pressing the upper mold and the lower mold.

[0010] In some possible implementations, the circuit board further includes electronic components mounted on the second outer circuit layer, and the lower mold is provided with a avoidance groove connected to the accommodating cavity, and the avoidance groove is used to accommodate the electronic components during the pressing.

[0011] The present application also provides a display module, comprising a display module. The display module also includes a circuit board and a conductive adhesive layer. The circuit board includes a first outer circuit layer, a first insulating adhesive layer, a support sheet, a second insulating adhesive layer, and a second outer circuit layer stacked in sequence. The support sheet is provided with an opening, and the second insulating adhesive layer is also filled in the opening to form a filling adhesive portion. The circuit board is also provided with a first blind hole that passes through the second insulating adhesive layer, the filling adhesive portion, and the first insulating adhesive layer in sequence. The bottom of the first blind hole corresponds to the first outer circuit layer. The first blind hole is provided with a first conductive portion, and the first outer circuit layer and the second outer circuit layer are electrically connected at least through the first conductive portion. The conductive adhesive layer is used to bond the display module to the first outer circuit layer. The conductive adhesive layer is made of a conductive resin. The conductive resin is electrically conductive along the thickness direction of the circuit board and electrically insulated along the extended plane of the circuit board.

[0012] In some possible implementations, an isolation layer is further provided in the first insulating adhesive layer, and the isolation layer is made of polyimide or glass fiber.

[0013] In some possible implementations, the circuit board further includes a first dielectric layer and an intermediate circuit layer disposed between the second insulating adhesive layer and the second outer circuit layer, the first blind hole also passes through the intermediate circuit layer and the first dielectric layer, and the intermediate circuit layer is electrically connected to the first outer circuit layer through the first conductive portion.

[0014] In some possible implementations, the circuit board further includes a covering layer and electronic components, the covering layer is provided on the second outer circuit layer, and a portion of the second outer circuit layer is exposed from the covering layer, and the electronic components are mounted on the second outer circuit layer exposed from the covering layer.

[0015] In this application, the display module is connected to the first outer circuit layer of the circuit board via conductive adhesive, thereby integrating the two and achieving electrical connection. Since the support sheet can be made of a highly rigid metal, the support sheet ensures more uniform pressure during lamination using a laminating jig, improving the flatness of the display module after lamination and ensuring good electrical continuity between the display module and the first outer circuit layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A cross-sectional view of a copper foil substrate provided in one embodiment of the present application.

[0017] Figure 2 For the general Figure 1 The cross-sectional view of the copper foil substrate after the first copper foil layer is etched into the first circuit layer is shown.

[0018] Figure 3 For Figure 2 The figure shows a cross-sectional view of the first circuit layer after the first insulating adhesive layer and the supporting sheet are laminated.

[0019] Figure 4 For Figure 3 A cross-sectional view of the support sheet after an opening is opened is shown.

[0020] Figure 5 For Figure 4 The figure shows a cross-sectional view of the support sheet after the second insulating adhesive layer, the first dielectric layer and the third copper foil layer are laminated onto the support sheet.

[0021] Figure 6 For Figure 5 A cross-sectional view of the product after the first conductive portion is provided and the third copper foil layer is etched into the second circuit layer.

[0022] Figure 7 For Figure 6 A cross-sectional view of the second circuit layer after a third circuit layer and a covering layer are formed on the second circuit layer is shown.

[0023] Figure 8 For the general Figure 7 A cross-sectional view showing the second copper foil layer removed.

[0024] Figure 9 For the general Figure 8 A cross-sectional view after the resist layer is removed is shown.

[0025] Figure 10 For Figure 9 The cross-sectional views of the first circuit layer and the third circuit layer after surface treatment are shown.

[0026] Figure 11 For Figure 10 A cross-sectional view of a circuit board obtained after electronic components are mounted on the third circuit layer is shown.

[0027] Figure 12 To press the display module onto the Figure 11 A cross-sectional view of the back of the circuit board is shown.

[0028] Figure 13 To remove Figure 12 A cross-sectional view of the display module obtained after the jig is pressed together is shown.

[0029] Description of main component symbols

[0030] Circuit board 1

[0031] Pressing fixture 2

[0032] Upper mold 2a

[0033] Lower mold 2b

[0034] Accommodation cavity 2c

[0035] Avoidance slot 2d

[0036] Copper foil substrate 10

[0037] First copper foil layer 11

[0038] Resist layer 12

[0039] Second copper foil layer 13

[0040] First circuit layer 14

[0041] First insulating rubber layer 20

[0042] Support sheet 21

[0043] Isolation layer 22

[0044] Second insulating rubber layer 30

[0045] First dielectric layer 31

[0046] The third copper foil layer 32

[0047] Second circuit layer 33

[0048] First blind hole 34

[0049] First conductive portion 35

[0050] The third insulating rubber layer 40

[0051] Second dielectric layer 41

[0052] The third circuit layer 43

[0053] Second blind hole 44

[0054] Second conductive portion 45

[0055] Covering layer 50

[0056] Electronic components 60

[0057] Circuit board 100

[0058] Connection port 140

[0059] Second surface treatment layer 141

[0060] Display module 200

[0061] Conductive adhesive layer 201

[0062] Opening 210

[0063] Display module 300

[0064] Filling rubber part 301

[0065] Connection pad 430

[0066] First surface treatment layer 431

[0067] The following specific implementation methods will further illustrate the present application in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0068] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments.

[0069] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application.

[0070] One embodiment of the present application provides a method for manufacturing a display module. The order of the steps of the manufacturing method can be changed according to different requirements, and some steps can be omitted or combined. The manufacturing method includes the following steps:

[0071] Step 1, see Figure 1 , providing a copper foil substrate 10, including a first copper foil layer 11, an anti-etching layer 12 and a second copper foil layer 13 stacked in sequence.

[0072] In some embodiments, the anti-etching layer 12 may be a nickel layer, a nickel / chromium layer, or a nickel / phosphorus layer.

[0073] Step 2, please refer to Figure 2 , the first copper foil layer 11 is etched into a first circuit layer 14 .

[0074] In some embodiments, the first circuit layer 14 can be formed by etching using a subtractive process. Etching can be performed using an alkaline etchant, such as a copper-ammonia chloride etchant. The resist layer 12 is insoluble in the alkaline etchant and, therefore, is not etched during the etching process of the first copper foil layer 11.

[0075] Step 3, please refer to Figure 3 , the first insulating adhesive layer 20 and the supporting sheet 21 are sequentially pressed onto the first circuit layer 14 .

[0076] In some embodiments, the support sheet 21 is made of a metal with high rigidity, such as steel, and has a thickness of 0.03 mm to 0.2 mm.

[0077] The first insulating adhesive layer 20 may be in a semi-cured state and fill the gaps between the circuits of the first circuit layer 14 during lamination. The first insulating adhesive layer 20 may be made of a viscous insulating resin, such as at least one of epoxy resin, polypropylene, polyurethane, phenolic resin, urea-formaldehyde resin, melamine-formaldehyde resin, and polyimide.

[0078] In some embodiments, the first insulating adhesive layer 20 is further provided with an isolation layer 22 for ensuring electrical isolation between the first circuit layer 14 and the support sheet 21. The isolation layer 22 may be made of polyimide or glass fiber with high insulation performance.

[0079] Step 4, please refer to Figure 4 , a plurality of openings 210 are opened in the support sheet 21 .

[0080] In some embodiments, the opening 210 may be etched by a metal etching process, which may include dry etching and wet etching processes.

[0081] Step 5, please refer to Figure 5 , the second insulating adhesive layer 30 , the first dielectric layer 31 and the third copper foil layer 32 are sequentially laminated on the support sheet 21 having the opening 210 .

[0082] The second insulating adhesive layer 30 may be in a semi-cured state and may fill the opening 210 during lamination to form a filling adhesive portion 301. The second insulating adhesive layer 30 may be made of a viscous insulating resin, such as at least one of epoxy resin, polypropylene, polyurethane, phenolic resin, urea-formaldehyde resin, melamine-formaldehyde resin, and polyimide.

[0083] In some embodiments, the material of the first dielectric layer 31 can be selected from polyimide (PI), liquid crystal polymer (LCP), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and the like.

[0084] Step 6, please refer to Figure 6 A plurality of first blind vias 34 are formed, sequentially penetrating the third copper foil layer 32, the first dielectric layer 31, the second insulating adhesive layer 30, the filler portion 301, and the first insulating adhesive layer 20. The bottoms of the first blind vias 34 correspond to the first circuit layer 14. Then, first conductive portions 35 are formed by electroplating in the first blind vias 34, and the third copper foil layer 32 is etched to form the second circuit layer 33. In this way, the second circuit layer 33 is electrically connected to the first circuit layer 14 via the first conductive portions 35.

[0085] In some embodiments, the second circuit layer 33 may be formed by etching using a subtractive process. The etching may be performed using an alkaline etchant, such as ammonium copper chloride etchant.

[0086] In some embodiments, the first blind hole 34 may be formed by laser drilling or mechanical drilling.

[0087] Step 7, please refer to Figure 7 At least one third circuit layer 43 electrically connected to the second circuit layer 33 is formed on the second circuit layer 33 through a build-up process, and a covering layer 50 is formed on the outermost third circuit layer 43, with a portion of the third circuit layer 43 exposed from the covering layer 50 to form a connection pad 430.

[0088] Specifically, the third circuit layer 43 can be formed by a method similar to steps 5 and 6. The formation of a third circuit layer 43 is described as an example. Figure 7 As shown, a third insulating adhesive layer 40, a second dielectric layer 41, and a fourth copper foil layer (not shown) are sequentially laminated onto the second circuit layer 33. A plurality of second blind vias 44 are formed, sequentially penetrating the fourth copper foil layer, the second dielectric layer 41, and the third insulating adhesive layer 40. The bottoms of the second blind vias 44 correspond to the second circuit layer 33. Second conductive portions 45 are then electroplated in the second blind vias 44, and the fourth copper foil layer is etched to form the third circuit layer 43. The third circuit layer 43 is electrically connected to the second circuit layer 33 via the second conductive portions. In the vertical direction (i.e., the thickness direction of the resulting circuit board 100), the second conductive portions are staggered with the first conductive portions.

[0089] The material of the third insulating adhesive layer 40 can be the same as that of the second insulating adhesive layer 30 , and the material of the second dielectric layer 41 can be the same as that of the first dielectric layer 31 .

[0090] It is understandable that Figure 7 As shown, after at least one third wiring layer 43 is formed on the second wiring layer 33 in step seven, the first wiring layer 14 serves as the first outer wiring layer, the outermost third wiring layer 43 serves as the second outer wiring layer, and the second wiring layer 33 and the other third wiring layers 43 serve as intermediate wiring layers. The number of third wiring layers 43 can be set according to the total number of wiring layers required.

[0091] In other embodiments, step seven may be omitted. In this case, the first circuit layer 14 serves as the first outer circuit layer, and the second circuit layer 33 serves as the second outer circuit layer.

[0092] In some embodiments, the cover layer 50 may be a solder resist or a coverlay film (CVL).

[0093] Step 8, see Figure 8, the second copper foil layer 13 is etched away to expose the anti-etching layer 12.

[0094] In some embodiments, the second copper foil layer 13 can be etched by an alkaline etching solution. Since the resist layer 12 is insoluble in the alkaline etching solution, the resist layer 12 will not be etched simultaneously during the etching process of the second copper foil layer 13.

[0095] Step 9, please refer to Figure 9 The resist layer 12 is removed to expose the first circuit layer 14. The first circuit layer 14 includes a plurality of connection ports 140 (I / O ports) for subsequent electrical connection with the display module.

[0096] For step 10, please refer to Figure 10 Surface treatment is performed on the connection pad 430 and the connection port 140 to obtain a first surface treatment layer 431 and a second surface treatment layer 141. At this point, the circuit substrate 1 is obtained.

[0097] The first surface treatment layer 431 is used to prevent oxidation on the surface of the connection pad 430, and the second surface treatment layer 141 is used to prevent oxidation on the surface of the connection port 140, which could affect its electrical performance. In some embodiments, the first surface treatment layer 431 or the second surface treatment layer 141 can be a chemically plated layer formed by methods such as chemical gold plating or chemical nickel plating, or can also be an organic solder resist (OSP).

[0098] In some embodiments, in order to ensure that the subsequent display module 200 (see Figure 12 and Figure 13 ) to ensure uniformity of display, prevent problems such as ripples and color difference, and at the same time, in order to ensure good conductivity between the connection port 140 and the display module 200, the thickness of the second surface treatment layer 141 does not exceed 1 micron.

[0099] For step 11, please refer to Figure 11 , electronic components 60 are mounted on the connection pads 430 to obtain the circuit board 100.

[0100] In some embodiments, the electronic component 60 may be mounted by surface mount technology (SMT). The electronic component 60 may be a chip, a resistor, or a capacitor.

[0101] Since the support sheet 21 is made of metal with high rigidity, it can provide support when the electronic component 60 is installed.

[0102] In some embodiments, the circuit board 100 may be a hard board or a soft board.

[0103] For step 12, please refer to Figure 12 and Figure 13, provide a pressing jig 2, which includes an upper mold 2a and a lower mold 2b. The upper mold 2a and the lower mold 2b are arranged relative to each other and surround a receiving cavity 2c. Then, the intermediate body formed by stacking the display module 200, the conductive adhesive layer 201 and the circuit board 100 in sequence is placed in the receiving cavity 2c, and the display module 200 and the electronic component 60 are respectively facing the upper mold 2a and the lower mold 2b. Then, the upper mold 2a and the lower mold 2b are pressed together so that the display module 200 is adhered to the second surface treatment layer 141 through the conductive adhesive layer 201. Remove the pressing jig 2 to obtain the display module 300.

[0104] In some embodiments, the conductive adhesive layer 201 is made of a conductive resin with resistive properties that provide electrical continuity in the Z-axis direction (i.e., the thickness direction of the circuit board 100) and electrical insulation in the XY plane (i.e., the extended plane of the circuit board 100). Thus, the conductive adhesive layer 201 can connect the display module 200 and the connection port 140 of the circuit board 100, ensuring electrical continuity, while also preventing adjacent connection ports 140 from being connected. In some specific embodiments, the conductive adhesive layer 201 is made of anisotropic conductive paste (ACF).

[0105] In some embodiments, the lower mold 2b is provided with a relief groove 2d that communicates with the receiving cavity 2c. When the circuit board 100 with the display module 200 is placed in the receiving cavity 2c, the electronic component 60 can be received in the relief groove 2d, thereby preventing damage to the electronic component 60 during the pressing process.

[0106] Furthermore, it is understood that because the support sheet 21 is made of a highly rigid metal, the presence of the support sheet 21 during lamination using a laminating jig ensures more uniform pressure during lamination, thereby improving the flatness of the display module 300 after lamination. Furthermore, even if the presence of the relief grooves 2d prevents pressure from being applied to the electronic components 60, the presence of the support sheet 21 ensures more uniform pressure across the connection ports 140 of the first circuit layer 14, thereby ensuring good electrical connectivity between the display module 200 and the connection ports 140.

[0107] In some embodiments, the display module 200 includes a display screen and thin film transistors stacked in sequence. The thin film transistors are used to drive each pixel of the display screen to operate normally.

[0108] See also Figure 13 One embodiment of the present application further provides a display module 300 , including a circuit board 100 and a display module 200 .

[0109] Circuit board 100 includes a first circuit layer 14, a first insulating adhesive layer 20, a support sheet 21, a second insulating adhesive layer 30, a first dielectric layer 31, a second circuit layer 33, a third insulating adhesive layer 40, a second dielectric layer 41, a third circuit layer 43, a cover layer 50, and electronic components 60, stacked in sequence. First insulating adhesive layer 20, made of a viscous insulating resin, fills the gaps between the circuits of first circuit layer 14. Support sheet 21 has a plurality of openings 210 defined therein, and second insulating adhesive layer 30 fills these openings 210 to form a filling adhesive portion 301.

[0110] Circuit board 100 also includes multiple first blind vias 34 that sequentially penetrate second circuit layer 33, first dielectric layer 31, second insulating adhesive layer 30, filler adhesive portion 301, and first insulating adhesive layer 20. The bottoms of first blind vias 34 correspond to first circuit layer 14. First conductive portions 35 are provided in first blind vias 34, electrically connecting second circuit layer 33 to first circuit layer 14 via first conductive portions 35. Circuit board 100 also includes multiple second blind vias 44 that sequentially penetrate third circuit layer 43, second dielectric layer 41, and third insulating adhesive layer 40. The bottoms of second blind vias 44 correspond to second circuit layer 33. Second conductive portions 45 are provided in second blind vias 44, electrically connecting third circuit layer 43 to second circuit layer 33 via second conductive portions.

[0111] A portion of the third circuit layer 43 is exposed from the cover layer 50 to form a connection pad 430 . The electronic component 60 is mounted on the connection pad 430 .

[0112] The first circuit layer 14 includes a plurality of connection ports 140, to which the display module 200 is bonded via a conductive adhesive layer 201. In some embodiments, the conductive adhesive layer 201 is made of a conductive resin having resistive properties that provide electrical continuity in the Z-axis direction (i.e., the thickness direction of the circuit board 100) and electrical insulation in the XY plane (i.e., the plane along which the circuit board 100 extends). Thus, the conductive adhesive layer 201 connects the display module 200 to the connection ports 140 of the circuit board 100, ensuring electrical continuity while preventing adjacent connection ports 140 from connecting. In some specific embodiments, the conductive adhesive layer 201 is made of anisotropic conductive paste (ACF).

[0113] In some embodiments, the support sheet 21 is made of a metal with high rigidity, such as steel, and has a thickness of 0.03 mm to 0.2 mm.

[0114] In some embodiments, the first insulating adhesive layer 20 is further provided with an isolation layer 22 for ensuring electrical isolation between the first circuit layer 14 and the support sheet 21. The isolation layer 22 may be made of polyimide or glass fiber with high insulation performance.

[0115] The present application connects the display module 200 to the connection port 140 of the circuit board 100 through conductive glue, thereby integrating the two and achieving electrical connection. Since the material of the support sheet 21 is a metal with high rigidity, the setting of the support sheet 21 can make the pressure more uniform during the pressing process using a pressing jig, thereby improving the flatness of the display module 300 after pressing and the good conduction between the display module 200 and the connection port 140. On the other hand, the present application also installs an electronic component 60 on the connection pad 430 of the circuit board 100, so that the circuit board 100 can serve as a bridge connecting the thin film transistor of the display module 200 and the electronic component 60. The installation of the electronic component 60 can adopt the mainstream surface mounting process and is not limited to the use of ACF installation, thereby improving the flexibility of the process.

[0116] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and are not intended to limit the present application. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present application.

Claims

1. A method for preparing a display module, characterized in that: The steps include: A circuit board is provided, comprising a first outer circuit layer, a first insulating adhesive layer, a support sheet, a second insulating adhesive layer, and a second outer circuit layer stacked in sequence, the support sheet having an opening, the second insulating adhesive layer further filling the opening to form a filling adhesive portion, the circuit board further having a first blind hole sequentially extending through the second insulating adhesive layer, the filling adhesive portion, and the first insulating adhesive layer, the bottom of the first blind hole corresponding to the first outer circuit layer, the first blind hole having a first conductive portion, the first outer circuit layer and the second outer circuit layer being electrically connected at least via the first conductive portion, and the circuit board further comprising an electronic component mounted on a side of the second outer circuit layer facing away from the second insulating adhesive layer; A conductive adhesive layer and a display module are sequentially laminated on the first outer circuit layer. The conductive adhesive layer is made of conductive resin. The conductive resin is electrically conductive along the thickness direction of the circuit board and electrically insulated along the extended plane of the circuit board. The display module is adhered to the first outer circuit layer through the conductive adhesive layer, thereby producing the display module.

2. The method for preparing a display module according to claim 1, wherein: An isolation layer is further provided in the first insulating adhesive layer, and the isolation layer is made of polyimide or glass fiber.

3. The method for preparing a display module according to claim 1, wherein: The circuit board also includes a first dielectric layer and an intermediate circuit layer arranged between the second insulating glue layer and the second outer circuit layer. The first blind hole also penetrates the intermediate circuit layer and the first dielectric layer. The intermediate circuit layer is electrically connected to the first outer circuit layer through the first conductive portion.

4. The method for preparing a display module according to claim 3, wherein: The method for preparing the circuit board comprises the following steps: Providing a copper foil substrate, the copper foil substrate comprising a first copper foil layer; Etching the first copper foil layer into the first outer circuit layer; Laminating the first insulating adhesive layer and the supporting sheet in sequence on the first outer circuit layer; opening the opening in the support sheet; sequentially pressing the second insulating adhesive layer, the first dielectric layer and the third copper foil layer on the support sheet having the opening; The first blind hole is opened, which sequentially passes through the third copper foil layer, the first dielectric layer, the second insulating adhesive layer, the filling adhesive portion, and the first insulating adhesive layer, and the first conductive portion is formed by electroplating in the first blind hole. The second outer circuit layer is formed on the middle circuit layer through a build-up process.

5. The method for preparing a display module according to claim 1, wherein: The pressing comprises: Providing a pressing jig, the pressing jig comprising an upper die and a lower die, the upper die and the lower die being arranged opposite to each other and surrounding a receiving cavity; Placing an intermediate body formed by sequentially stacking the display module, the conductive adhesive layer, and the circuit board into the receiving cavity, with the display module and the second outer circuit layer facing the upper mold and the lower mold respectively; The upper mold and the lower mold are pressed together.

6. The method for preparing a display module according to claim 5, wherein: The lower mold is provided with a relief groove communicated with the receiving cavity, and the relief groove is used to receive the electronic component during the pressing.

7. A display module, comprising a display module, characterized in that: The display module further includes: A circuit board comprising a first outer circuit layer, a first insulating adhesive layer, a support sheet, a second insulating adhesive layer, and a second outer circuit layer stacked in sequence, the support sheet having an opening, the second insulating adhesive layer further filling the opening to form a filling adhesive portion, the circuit board further having a first blind hole sequentially extending through the second insulating adhesive layer, the filling adhesive portion, and the first insulating adhesive layer, the bottom of the first blind hole corresponding to the first outer circuit layer, the first blind hole having a first conductive portion, the first outer circuit layer and the second outer circuit layer being electrically connected at least via the first conductive portion, the circuit board further comprising an electronic component mounted on a side of the second outer circuit layer facing away from the second insulating adhesive layer; The conductive adhesive layer is used to bond the display module to the first outer circuit layer. The conductive adhesive layer is made of conductive resin. The conductive resin is electrically conductive along the thickness direction of the circuit board and electrically insulated along the extension plane of the circuit board.

8. The display module according to claim 7, wherein: An isolation layer is further provided in the first insulating adhesive layer, and the isolation layer is made of polyimide or glass fiber.

9. The display module according to claim 7, wherein: The circuit board also includes a first dielectric layer and an intermediate circuit layer arranged between the second insulating glue layer and the second outer circuit layer. The first blind hole also penetrates the intermediate circuit layer and the first dielectric layer. The intermediate circuit layer is electrically connected to the first outer circuit layer through the first conductive portion.

10. The display module according to claim 7, wherein: The circuit board further includes a covering layer, which is disposed on the second outer circuit layer, and a portion of the second outer circuit layer is exposed from the covering layer. The electronic component is mounted on the second outer circuit layer exposed from the covering layer.

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