Circuit substrate, manufacturing method and electronic equipment

Abstract

The invention discloses a circuit substrate, a manufacturing method and electronic equipment, and relates to the technical field of circuit board processing. The circuit substrate manufacturing method comprises the following steps: providing an electrolytic copper foil, and arranging a glue layer on one side of the electrolytic copper foil; etching the electrolytic copper foil to prepare a plurality of buried copper sheets; a glass fiber plate is provided, and a plurality of through grooves are formed in the glass fiber plate; the buried copper sheets are arranged in the through grooves in a one-to-one correspondence mode, and gaps are formed between the buried copper sheets and the inner walls of the through grooves; the gap is filled with colloid; and removing the adhesive layer. According to the circuit substrate manufacturing method provided by the invention, the circuit substrate can be made thinner, and the application range is wider.

Description

Technical Field

[0001] This application relates to the field of circuit board processing technology, and in particular to a circuit board, a manufacturing method, and an electronic device. Background Technology

[0002] A copper-embedded circuit board, or simply an embedded copper circuit board, allows the heat generated by the chips and other structures connected to the circuit board during operation to be dissipated to the outside through the copper block.

[0003] In related technologies, the thickness of circuit boards with embedded copper blocks can only be made to be greater than 0.4mm. The method of embedding copper blocks cannot be applied to ultra-thin circuit boards, and its application range is narrow. Summary of the Invention

[0004] This application provides a circuit board, a manufacturing method, and an electronic device, enabling the circuit board to be made thinner and its applications to be wider.

[0005] In a first aspect, this application provides a method for fabricating a circuit board, comprising: An electrolytic copper foil is provided, and an adhesive layer is disposed on one side of the electrolytic copper foil; The electrolytic copper foil is etched to obtain multiple embedded copper sheets; A fiberglass board is provided, and a plurality of through grooves are formed on the fiberglass board; The plurality of embedded copper sheets are arranged one-to-one in the plurality of through slots, and a gap is formed between the embedded copper sheets and the inner wall of the through slots; The gap is filled with colloid; Remove the adhesive layer.

[0006] In some possible implementations, filling the gap with a colloid includes: A release film is provided on the side of the fiberglass board away from the adhesive layer, and the release film has an opening communicating with the gap; A coated copper foil is disposed on the side of the release film away from the electrolytic copper foil, with the adhesive on the coated copper foil facing the release film. The coated copper foil is subjected to rapid pressing, causing the adhesive on the coated copper foil to fill the gap and form a colloid; Remove the release film and the coated copper foil.

[0007] In some possible implementations, the gap is arranged around the embedded copper sheet, with the opening partially opposite the gap and avoiding the embedded copper sheet.

[0008] In some possible implementations, the gap comprises four structural segments connected in sequence, with two of the structural segments arranged opposite each other corresponding to two different openings.

[0009] In some possible implementations, etching the electrolytic copper foil to produce multiple embedded copper sheets includes: A dry film is disposed on the side of the electrolytic copper foil opposite to the adhesive layer; The dry film is exposed and developed; The electrolytic copper foil is etched to obtain the plurality of embedded copper sheets; Remove the dry film.

[0010] In some possible implementations, the adhesive layer is tacky on the side facing the electrolytic copper foil and non-tacky on the side away from the electrolytic copper foil.

[0011] In some possible implementations, the thickness h of the adhesive layer is set to 1 mm ≤ h ≤ 2 mm.

[0012] Secondly, this application also provides a circuit board, which is manufactured by the circuit board manufacturing method described in the above embodiments.

[0013] Thirdly, this application also provides an electronic device, including the circuit board described in the above embodiments.

[0014] In some possible implementations, electrical components are disposed on the circuit board, and the electrical components are in contact with the embedded copper sheet.

[0015] The beneficial effects of this application are as follows: The circuit board manufacturing method provided by this application can embed copper sheets made of electrolytic copper foil into the circuit board, making the embedded copper structure in the circuit board thinner. This allows for the application in thinner circuit boards, making the resulting circuit boards suitable for thinner and lighter electronic devices. This effectively solves the heat dissipation problem of thin and light electronic devices, has a wider range of application prospects, ensures the smooth operation of various electrical components on the circuit board, extends their service life, and thus extends the service life of electronic devices. Furthermore, there is no need to set up a separate heat dissipation structure on the circuit board in electronic devices, which can further reduce the size of electronic devices and save costs. In addition, the embedded copper sheets in the circuit board can enhance the local mechanical strength of the circuit board. The embedded copper sheets can better integrate into the circuit board, providing more stable support for connectors or heat sinks that bear weight, and improving the integration of the embedded copper sheets with the circuit board, reducing the possibility of damage. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 A flowchart illustrating the circuit board fabrication method in some embodiments is shown; Figure 2 Schematic diagrams of the electrolytic copper foil and adhesive layer in some embodiments are shown; Figure 3 A flowchart of step S200 in some embodiments is shown; Figure 4 Schematic diagrams of the etched electrolytic copper foil structure are shown in some embodiments; Figure 5 A schematic diagram of the structure after the fiberglass board groove is shown in some embodiments; Figure 6 A flowchart of step S500 in some embodiments is shown; Figure 7 Schematic diagrams of structures with release films in some embodiments are shown; Figure 8 Schematic diagrams of structures with coated copper foil are shown in some embodiments; Figure 9 Schematic diagrams of the structure during fast pressing are shown in some embodiments; Figure 10 Schematic diagrams of the embedded copper core board in some embodiments are shown.

[0018] Explanation of key component symbols: 1000- Embedded copper core board; 100 - Electrolytic copper foil; 110 - Embedded copper sheet; 200 - Release film; 210 - Window opening; 300 - Coated copper foil; 310 - Colloid; 400 - Adhesive layer; 500-dry film; 600 - Fiberglass board; 610 - Through groove; 700-gap. Detailed Implementation

[0019] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0020] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0021] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0022] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0023] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0024] The embodiment provides a method for manufacturing a circuit board, which can be used to manufacture a circuit board and can achieve rapid heat dissipation of electrical components on the circuit board.

[0025] like Figures 1 to 3 As shown, in some embodiments, the circuit board fabrication method may include: S100, providing an electrolytic copper foil 100, and depositing an adhesive layer 400 on one side of the electrolytic copper foil 100.

[0026] In some embodiments, the electrolytic copper foil 100 may be an electrolytic copper foil 100 with a preset thickness. Specifically, the thickness of the electrolytic copper foil 100 can be set according to the design requirements of the circuit board.

[0027] In this embodiment, an adhesive layer 400 can be adhered to one side of the electrolytic copper foil 100. The side of the adhesive layer 400 facing the electrolytic copper foil 100 is adhesive, enabling bonding with the electrolytic copper foil 100. The side of the adhesive layer 400 away from the electrolytic copper foil 100 is non-adhesive, i.e., non-adhesive, preventing the adhesive layer 400 from bonding with other structures and detaching from the electrolytic copper foil 100.

[0028] In some embodiments, the thickness h of the adhesive layer 400 can be set to 1 mm ≤ h ≤ 2 mm, which can provide stable and reliable bonding and support for the electrolytic copper foil 100, and ensure the relative fixation between multiple embedded copper sheets 110 during subsequent processing, thereby improving processing efficiency and accuracy. Exemplarily, the thickness h of the adhesive layer 400 can be set to 1 mm, 1.2 mm, 1.5 mm, 1.75 mm, 1.9 mm, 2 mm, or any other dimension from 1 mm to 2 mm.

[0029] S200, etching is performed on the electrolytic copper foil 100 to form multiple embedded copper sheets 110.

[0030] In this embodiment, multiple embedded copper sheets 110 can be spaced apart from each other, and the multiple embedded copper sheets 110 can be distributed according to the design of the circuit board, corresponding one-to-one in multiple preset positions. In this embodiment, the multiple embedded copper sheets 110 are pasted on the same adhesive layer 400, and the adhesion of the adhesive layer 400 prevents the embedded copper sheets 110 from moving, thus keeping each embedded copper sheet 110 in its corresponding preset position, and also keeping the embedded copper sheets 110 relatively fixed.

[0031] like Figures 2 to 4 As shown, in some embodiments, the electrolytic copper foil 100 is etched, and step S200 may specifically include the following operations: S210, a dry film 500 is provided on the side of the electrolytic copper foil 100 away from the adhesive layer 400.

[0032] S220 is used to expose and develop the dry film 500.

[0033] Thus, a portion of the dry film 500 at the position corresponding to the interval between two adjacent embedded copper sheets 110 can be removed.

[0034] S230, etching is performed on the electrolytic copper foil 100 to produce multiple embedded copper sheets 110.

[0035] In the embodiment, the portion of the electrolytic copper foil 100 exposed relative to the dry film 500 can be etched, and the electrolytic copper foil 100 at a preset position can be retained, thereby forming a buried copper sheet 110 at the preset position.

[0036] In some embodiments, when exposing and developing the dry film 500, the dry film 500 can be patterned according to the shape and preset position of the plurality of embedded copper sheets 110.

[0037] S240, remove dry film 500.

[0038] In the embodiment, the dry film 500 remaining on the surface of the embedded copper sheet 110 can be removed by processes such as dry stripping or wet stripping.

[0039] S300 provides a fiberglass board 600, and a plurality of through grooves 610 are formed on the fiberglass board 600.

[0040] like Figure 5 As shown, in this embodiment, multiple through slots 610 can be processed on the fiberglass board 600 by means of milling or other methods. That is, the through slots 610 can penetrate the fiberglass board 600 along its thickness direction. Furthermore, each of the multiple through slots 610 corresponds one-to-one with a multiple embedded copper sheet 110. Accordingly, when milling the fiberglass board 600, the milling positions of the fiberglass board 600 can be patterned according to the patterned design of the electrolytic copper foil 100. In addition, the single-sided dimension of the through slot 610 can be larger than the single-sided dimension of the embedded copper sheet 110; for example, the single-sided dimension of the through slot 610 can be 0.2 mm larger than the single-sided dimension of the embedded copper sheet 110.

[0041] S400, multiple embedded copper sheets 110 are arranged one-to-one in multiple through grooves 610, and a gap 700 is formed between the embedded copper sheets 110 and the inner wall of the through grooves 610.

[0042] like Figure 7 As shown in the embodiment, multiple embedded copper sheets 110 are attached to the same adhesive layer 400, thereby allowing multiple embedded copper sheets 110 to be simultaneously inserted into corresponding through slots 610 and their positions adjusted. The adhesive layer 400 can be confined to one side of the fiberglass board 600. On the one hand, this facilitates the placement of the embedded copper sheets 110 into the corresponding through slots 610; on the other hand, it improves the assembly efficiency of the embedded copper sheets 110 and the fiberglass board 600, thereby improving the processing efficiency of the circuit board.

[0043] In this embodiment, the sidewall of the embedded copper sheet 110 may be spaced apart from the inner wall of the through groove 610, forming a gap 700. In some embodiments, the gap 700 may be arranged around the embedded copper sheet 110, that is, the gap 700 may be in the form of a ring structure.

[0044] In other embodiments, part of the sidewall of the embedded copper sheet 110 may fit against the inner wall of the through groove 610, and the gap 700 may be a non-closed annular structure.

[0045] S500, fill the gap 700 with colloid 310.

[0046] like Figure 1 , Figures 6 to 10 In this embodiment, the gap 700 can be filled with colloid 310, thereby achieving relative fixation between the embedded copper sheet 110 and the fiberglass board 600, and also improving the fusion effect between the embedded copper sheet 110 and the fiberglass board 600. In some embodiments, step S500 may include: S510, a release film 200 is provided on the side of the fiberglass board 600 away from the adhesive layer 400, and the release film 200 has an opening 210 communicating with the gap 700.

[0047] In some embodiments, the release film 200 can be opened 210 according to the setting requirements of the through groove 610 on the fiberglass board 600 and the setting requirements of the embedded copper sheet 110. In the embodiments, the release film 200 can be cut by laser cutting or mechanical cutting to open 210 in the release film 200.

[0048] Afterwards, the release film 200 after the window is opened can be adhered to the side of the fiberglass board 600 away from the adhesive layer 400, and the gap 700 can be connected to at least one window 210. In addition, the side of the embedded copper sheet 110 away from the adhesive layer 400 can be covered by the release film 200.

[0049] In some embodiments, the embedded copper sheet 110 may be quadrilateral. Correspondingly, the gap 700 may also be a quadrilateral ring structure with four structural segments that are connected in sequence. In the embodiments, two opposite structural segments may be connected to two different openings 210 in a one-to-one correspondence.

[0050] In other embodiments, the embedded copper sheet 110 may also be circular or elliptical in shape. The gap 700 may be connected to one or three equal numbers of openings 210. That is, a portion of the structural segment of the gap 700 may be connected to an opening.

[0051] In other embodiments, after the release film 200 is adhered to the side of the fiberglass board 600 away from the adhesive layer 400, a window is then made in the release film 200.

[0052] S520, a coated copper foil 300 is provided on the side of the release film 200 away from the electrolytic copper foil 100, and the adhesive on the coated copper foil 300 is directed toward the side of the release film 200.

[0053] In this embodiment, the coated copper foil 300 can be single-sided coated, meaning that one side of the copper foil is coated with adhesive while the other side is not, thereby preventing adhesion between the coated copper foil 300 and the high-speed press. In this embodiment, the coated copper foil 300 can be adhered to the side of the release film 200 away from the embedded copper sheet 110, with the adhesive on the copper foil facing towards the release film 200. Correspondingly, the adhesive on the coated copper foil 300 can be opposite to the opening 210 on the release film 200. In some embodiments, the adhesive on the coated copper foil 300 can be polypropylene (PP) adhesive.

[0054] S530, the coated copper foil 300 is pressed quickly so that the adhesive on the coated copper foil 300 fills the gap 700 and forms a colloid 310.

[0055] In this embodiment, the coated copper foil 300 can be pressed quickly using a high-speed press or similar equipment, so that the adhesive on the coated copper foil 300 melts and flows into the gaps 700 through the opening 210, filling each gap 700 with adhesive. After the adhesive cures, a colloid 310 can be formed in the gaps 700, thus achieving the bonding and fixation of the embedded copper sheet 110 and the fiberglass board 600, and fusing the embedded copper sheet 110 into the fiberglass board 600.

[0056] In the embodiment, the release film 200 can act as an isolator between the embedded copper sheet 110 and the coated copper foil 300, preventing the adhesive on the coated copper foil 300 from adhering to the surface of the embedded copper sheet 110 and affecting the thermal conductivity of the embedded copper sheet 110.

[0057] In addition, in some embodiments, both structural segments of the gap 700 are connected to the opening 210, which can improve the efficiency of filling the gap 700 with adhesive, thereby improving the processing efficiency of the circuit board.

[0058] S540, remove release film 200 and coated copper foil 300.

[0059] In this embodiment, the release film 200 can be removed to separate the release film 200 from the embedded copper sheet 110. At the same time as removing the release film 200, the coated copper foil 300 on the release film 200 can also be removed, exposing the side of the embedded copper sheet 110 away from the adhesive layer 400.

[0060] S600, remove adhesive layer 400.

[0061] In the embodiment, the adhesive layer 400 can be separated from the embedded copper sheet 110 and the adhesive 310 by peeling, so that the side surface of the embedded copper sheet 110 facing the adhesive layer 400 and the side surface of the adhesive 310 facing the adhesive layer 400 are exposed, so as to obtain the embedded copper core board 1000.

[0062] In some embodiments, the method for manufacturing a circuit board further includes: S700, polishing.

[0063] In this embodiment, the surface of the embedded copper core board 1000 facing the release film 200 can be polished to make the surface of the colloid 310 facing away from the adhesive layer 400, the surface of the embedded copper sheet 110 facing away from the adhesive layer 400, and the surface of the fiberglass board 600 facing away from the adhesive layer 400 flush. Alternatively, the surfaces of the colloid 310 facing the adhesive layer 400, the surface of the embedded copper sheet 110 facing the adhesive layer 400, and the surface of the fiberglass board 600 facing the adhesive layer 400 can also be flush.

[0064] In this embodiment, step S500 may be performed after step S400 or before step S400.

[0065] It is understandable that circuit boards may also include structural layers such as prepreg and circuit layers. Circuit board fabrication methods may also include steps such as drilling, copper plating, and lamination, which will not be detailed here.

[0066] In this application, the electrolytic copper foil 100 has a tensile strength of 220 MPa to 260 MPa and a hardness of ≥60 HV. Compared to pure copper, the electrolytic copper foil 100 has higher tensile strength, and its hardness and flexibility are comparable to those of ultra-thin circuit boards. It also exhibits good heat and low-temperature resistance. This allows the embedded copper sheet 110 in the circuit board to integrate more harmoniously with other structures of the circuit board, reducing the possibility of damage. Simultaneously, it can be used to manufacture thinner circuit boards, with a thickness as low as 0.05 mm. This allows the resulting circuit boards to be used in thinner and lighter electronic devices, effectively solving the heat dissipation problem of thin and light electronic devices, and has a wider range of application prospects. It ensures the smooth operation of various electrical components on the circuit board, extending their service life and thus extending the service life of the electronic devices. Furthermore, it eliminates the need for a separate heat dissipation structure on the circuit board in electronic devices, further reducing the size of the electronic devices and saving costs. In addition, the embedded copper sheet 110 in the circuit board can enhance the local mechanical strength of the circuit board. The embedded copper sheet 110 can be better integrated into the circuit board, providing more stable support for connectors or heat sinks that bear weight.

[0067] The embodiment also provides a circuit board, which can be manufactured by the circuit board manufacturing method provided in the embodiment. The circuit board may include structural layers such as a buried copper core board 1000, a prepreg, and circuit layers, and these structural layers can be laminated together. The buried copper sheet 110 can be used to conduct heat in the circuit board, quickly transferring the heat generated by the electrical components connected to the circuit board to a heat sink on the other side or the outside environment, thus achieving rapid heat dissipation of the electrical components.

[0068] The embodiment also provides an electronic device, which may include the circuit board provided in the embodiment and electrical components disposed on the circuit board, the electrical components being in contact with the embedded copper sheet 110.

[0069] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0070] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A method for manufacturing a circuit board, characterized in that, include: An electrolytic copper foil (100) is provided, and an adhesive layer (400) is provided on one side of the electrolytic copper foil (100). The electrolytic copper foil (100) is etched to obtain a plurality of embedded copper sheets (110). A fiberglass board (600) is provided, and a plurality of through grooves (610) are formed on the fiberglass board (600). The plurality of embedded copper sheets (110) are arranged one-to-one in the plurality of through grooves (610), and a gap (700) is formed between the embedded copper sheets (110) and the inner wall of the through grooves (610). The gap (700) is filled with colloid (310); Remove the adhesive layer (400).

2. The method for fabricating a circuit board according to claim 1, characterized in that, The filling of the gap (700) with colloid (310) includes: A release film (200) is provided on the side of the fiberglass board (600) away from the adhesive layer (400), and the release film (200) has an opening (210) communicating with the gap (700). A coated copper foil (300) is provided on the side of the release film (200) away from the electrolytic copper foil (100), and the adhesive on the coated copper foil (300) is directed toward the release film (200). The coated copper foil (300) is subjected to rapid pressing, so that the adhesive on the coated copper foil (300) fills the gap (700) and forms a colloid (310). Remove the release film (200) and the coated copper foil (300).

3. The method for fabricating a circuit board according to claim 2, characterized in that, The gap (700) is arranged around the embedded copper sheet (110) for a period of time, and the window (210) is partially opposite to the gap (700) and avoids the embedded copper sheet (110).

4. The method for fabricating a circuit board according to claim 3, characterized in that, The gap (700) includes four structural segments connected in sequence, and two of the structural segments arranged opposite to each other are connected to two different windows (210).

5. The method for fabricating a circuit board according to claim 1, characterized in that, The etching of the electrolytic copper foil (100) to produce a plurality of embedded copper sheets (110) includes: A dry film (500) is provided on the side of the electrolytic copper foil (100) opposite to the adhesive layer (400). The dry film (500) is exposed and developed; The electrolytic copper foil (100) is etched to obtain the plurality of embedded copper sheets (110). Remove the dry film (500).

6. The method for fabricating a circuit board according to claim 1, characterized in that, The adhesive layer (400) is tacky on the side facing the electrolytic copper foil (100), and the adhesive layer (400) is non-tacky on the side away from the electrolytic copper foil (100).

7. The method for manufacturing a circuit board according to any one of claims 1 to 6, characterized in that, The thickness h of the adhesive layer (400) is set to 1mm≤h≤2mm.

8. A circuit board, characterized in that, It is manufactured by the circuit board fabrication method as described in any one of claims 1 to 7.

9. An electronic device, characterized in that, Includes the circuit board as described in claim 8.

10. The electronic device according to claim 9, characterized in that, Electrical components are disposed on the circuit board, and the electrical components are in contact with the embedded copper sheet (110).

Images