Circuit board, manufacturing method thereof and electronic equipment

Abstract

The invention discloses a circuit board and a manufacturing method thereof, and electronic equipment, and the circuit board comprises at least two core boards which are arranged in a laminated manner, and an interconnection board is arranged between every two adjacent core boards; wherein a first embedding part and a second embedding part are arranged on the two opposite sides, facing the two adjacent core plates connected with the interconnection plate, of the interconnection plate respectively, the two adjacent core plates are provided with a third embedding part and a fourth embedding part corresponding to the first embedding part and the second embedding part respectively, the first embedding part is embedded in the third embedding part, and the second embedding part is embedded in the fourth embedding part. And the two adjacent core plates are connected. According to the mode, the circuit board effectively realizes embedded connection between different core boards through the interconnection board, the interconnection density is remarkably improved, the lamination frequency can be effectively reduced, the technological process is simplified, and the reliability is relatively high, so that the production efficiency and the product quality can be effectively improved.

Description

Technical Field

[0001] The present application relates to the technical field of circuit boards, and particularly to a circuit board, a manufacturing method thereof, and an electronic device. Background Art

[0002] With the development of circuit board products towards miniaturization and multi-function, product design tends to be high-density. This makes the manufacturing of HDI (High Density Interconnector) board parts complex. Especially in the process of multiple laminations, due to the accumulation of layers, the processing flow becomes longer and the yield rate decreases. Summary of the Invention

[0003] The present application provides a circuit board, a manufacturing method thereof, and an electronic device to solve the problem that the manufacturing method of the circuit board in the prior art is complex in the manufacturing of HDI board parts, especially in the process of multiple laminations, due to the accumulation of layers, there are problems such as longer processing flow and lower yield rate.

[0004] To solve the above technical problems, a technical solution adopted by the present application is: providing a circuit board, wherein the circuit board includes: at least two core boards arranged in a stacked manner, and an interconnection board is provided between every two adjacent core boards; wherein, the interconnection board is respectively provided with a first fitting part and a second fitting part on opposite sides facing the two adjacent core boards connected thereto, and the two adjacent core boards are respectively provided with a third fitting part and a fourth fitting part corresponding to the first fitting part and the second fitting part, the first fitting part is fitted into the third fitting part, and the second fitting part is fitted into the fourth fitting part to connect the two adjacent core boards.

[0005] Wherein, the first fitting part includes a first connecting boss, and the third fitting part correspondingly includes a first connecting groove, and the first connecting boss is embedded in the first connecting groove; the second fitting part includes a second connecting boss, and the fourth fitting part correspondingly includes a second connecting groove, and the second connecting boss is embedded in the second connecting groove.

[0006] Wherein, the first fitting part includes a third connecting groove, and the third fitting part correspondingly includes a third connecting boss, and the third connecting boss is embedded in the third connecting groove; the second fitting part includes a fourth connecting groove, and the fourth fitting part correspondingly includes a fourth connecting boss, and the fourth connecting boss is embedded in the fourth connecting groove.

[0007] Wherein, the first fitting part includes a fifth connecting groove and / or a fifth connecting boss, the third fitting part correspondingly includes a sixth connecting groove and / or a sixth connecting boss, the fifth connecting boss is embedded in the sixth connecting groove, and the sixth connecting boss is embedded in the fifth connecting groove; the second fitting part includes a seventh connecting groove and / or a seventh connecting boss, the fourth fitting part correspondingly includes an eighth connecting groove and / or an eighth connecting boss, the seventh connecting boss is embedded in the eighth connecting groove, and the eighth connecting boss is embedded in the seventh connecting groove.

[0008] Among them, the interconnection board includes an insulating layer, a first conductive layer and a second conductive layer provided on opposite sides of the insulating layer. A first fitting portion is provided in the first conductive layer, and a second fitting portion is provided in the second conductive layer.

[0009] Among them, a conductive through hole is further provided in the insulating layer, and the first conductive layer is connected to the second conductive layer through the conductive through hole.

[0010] To solve the above technical problems, another technical solution adopted by this application is: to provide a manufacturing method of a circuit board. Among them, the manufacturing method of the circuit board includes: providing at least two core boards; arranging an interconnection board between every two adjacent core boards; among them, the interconnection board is provided with a first fitting portion and a second fitting portion on opposite sides facing the two adjacent core boards connected thereto, and the two adjacent core boards are respectively provided with a third fitting portion and a fourth fitting portion corresponding to the first fitting portion and the second fitting portion. The first fitting portion is fitted into the third fitting portion, and the second fitting portion is fitted into the fourth fitting portion to connect the two adjacent core boards; laminating the stacked core boards and interconnection boards to obtain a circuit board.

[0011] Among them, after the step of providing at least two core boards and before arranging an interconnection board between every two adjacent core boards, it further includes: providing a substrate, forming a conductive through hole on the substrate; forming a first conductive layer and a second conductive layer on opposite sides of the substrate respectively to obtain an interconnection board; among them, the first conductive layer is connected to the second conductive layer through the conductive through hole, a first fitting portion is provided in the first conductive layer, and a second fitting portion is provided in the second conductive layer.

[0012] Among them, the step of providing a substrate and forming a conductive through hole on the substrate includes: providing a substrate, sequentially performing drilling, etching, flash plating, film pasting, first exposure and development, and pattern electroplating on the substrate to form a conductive through hole on the substrate; the step of forming a first conductive layer and a second conductive layer on opposite sides of the substrate respectively includes: sequentially performing wet film printing, second exposure and development, electroplating, film stripping, and flash etching on the substrate after pattern electroplating to form a first conductive layer and a second conductive layer on opposite sides of the substrate respectively.

[0013] To solve the above technical problems, another technical solution adopted by this application is: to provide an electronic device. Among them, the electronic device includes a housing and a circuit board connected to each other; among them, the circuit board is the circuit board described in any one of the above.

[0014] The beneficial effects of the present application are as follows: Different from the prior art, an interconnection board is provided between every two adjacent core boards in the circuit board provided by the present application. The interconnection board is provided with a first fitting portion and a second fitting portion on opposite sides facing the two adjacent core boards connected thereto. The two adjacent core boards are respectively provided with a third fitting portion and a fourth fitting portion corresponding to the first fitting portion and the second fitting portion. The first fitting portion is fitted into the third fitting portion, and the second fitting portion is fitted into the fourth fitting portion to connect the two adjacent core boards. Thus, a multi-level HDI board can be split into multiple sub-boards with fewer levels, that is, at least two core boards, and an embedded connection between different core boards is realized through the interconnection board, thereby significantly improving the interconnection density, effectively reducing the number of lamination times in the manufacturing process, simplifying the process flow, and having relatively high reliability, so as to effectively improve production efficiency and product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts. Among them:

[0016] Figure 1 is a schematic structural diagram of a first embodiment of the circuit board of the present application;

[0017] Figure 2 is a schematic structural diagram of a second embodiment of the circuit board of the present application;

[0018] Figure 3 is a schematic flowchart of a manufacturing method of the circuit board of the present application;

[0019] Figure 4 is Figure 3 a schematic flowchart of an embodiment corresponding to S32 in;

[0020] Figure 5a is Figure 3 a schematic flowchart of another embodiment corresponding to S32 in;

[0021] Figure 5b - Figure 5l is Figure 5a a schematic structural diagram of an embodiment corresponding to S3211 - S3212 in;

[0022] Figure 6 is a schematic structural diagram of an embodiment of an electronic device of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Apparently, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0024] The terms "first", "second", and "third" in the present application are only used for descriptive purposes, and cannot be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first", "second", and "third" may explicitly or implicitly include at least one of such features. In the description of the present application, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined. All directional indications (such as up, down, left, right, front, back...) in the embodiments of the present application are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally further include unlisted steps or units, or may optionally further include other steps or units inherent to these processes, methods, products, or devices.

[0025] Referring to "embodiments" herein means that specific features, structures, or characteristics described in connection with the embodiments may be included in at least one embodiment of the present application. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein may be combined with other embodiments.

[0026] The present application will be described in detail below with reference to the accompanying drawings and embodiments.

[0027] Please refer to Figure 1 , Figure 1 which is a schematic structural diagram of the first embodiment of the circuit board of the present application. In this embodiment, the circuit board 10 includes: at least two core boards 11 and an interconnection board 12.

[0028] Among them, each core board 11 can specifically be a single-layer patterned copper clad laminate, or can include at least two layers of patterned copper clad laminates. And between every two adjacent copper clad laminates among the at least two copper clad laminates, an insulating dielectric layer is stacked, and connection is achieved through metal vias arranged in the insulating dielectric layer. And the inner core board 11 can specifically further include passive components, such as any reasonable circuit elements like capacitors, resistors, etc., and / or one or more of other any reasonable materials that can be used for manufacturing a circuit board, such as copper plates, electroplated copper layers, conductive posts, heat dissipation plates, thermal conductive adhesives, etc., so as to be able to realize the pre-designed circuit logic through the patterned copper clad laminate, that is, the conductive circuit layer, and circuit units such as conductive posts and buried components. The present application does not make any limitation thereto.

[0029] Specifically, an interconnection board 12 is provided between every two adjacent core boards 11 to be used for realizing electrical connection and mechanical fixation between the two adjacent core boards 11, so that at least two core boards 11 are stacked.

[0030] And specifically, a circuit layer can further be provided inside the interconnection board 12 to realize the pre-designed circuit logic. The present application does not make any limitation thereto.

[0031] Among them, a first fitting portion 1201 and a second fitting portion 1202 are respectively provided on opposite side surfaces of each interconnection board 12, and each core board 11 is respectively provided with a third fitting portion (not shown in the figure) and a fourth fitting portion (not shown in the figure) corresponding to the first fitting portion 1201 and the second fitting portion 1202.

[0032] Specifically, the first fitting portion 1201 is provided on one side of the interconnection board 12 facing a core board 11 connected thereto and is used for fitting into the third fitting portion on the core board 11; the second fitting portion 1202 is provided on one side of the interconnection board 12 facing another core board 11 connected thereto and is used for fitting into the fourth fitting portion on the core board 11; the third fitting portion is provided on an adjacent core board 11 and corresponds to the first fitting portion 1201 of the interconnection board 12 to ensure that the two can be precisely fitted; the fourth fitting portion is provided on another adjacent core board 11 and corresponds to the second fitting portion 1202 of the interconnection board 12 to ensure that the two can be precisely fitted.

[0033] Through the fitting design of the first fitting part 1201, the second fitting part 1202, the third fitting part and the fourth fitting part, the mechanical strength between the core board 11 and the interconnection board 12 is increased, the delamination risk caused by vibration or impact is reduced, and the mechanical stability is enhanced. The fitting design not only provides physical support, but also can fill the fitting part with a conductive material (such as copper) to achieve reliable electrical connection between adjacent core boards 11, reduce contact resistance and signal loss, and improve the reliability of electrical connection. By integrating more circuit layers in a limited space, the overall density and functional complexity of the circuit board 10 are improved, and the space utilization rate is optimized. The clear fitting part design makes the manufacturing process more standardized and controllable, reduces the production cost and improves the production efficiency.

[0034] In the above solution, by splitting the multi-level HDI board parts into multiple sub-boards with fewer levels, that is, at least two core boards 11, and realizing the embedded connection between different core boards 11 through the interconnection board 12, the interconnection density is significantly increased, the number of lamination times in the manufacturing process can be effectively reduced, the process flow is simplified, and the reliability is relatively high, so that the production efficiency and product quality can be effectively improved. And by introducing the fitting part design, a stable mechanical connection and a reliable electrical connection can be achieved between adjacent core boards 11, thereby improving the overall performance and reliability of the multi-layer circuit board 10. This design is not only applicable to high-performance computing devices, communication devices and industrial control devices, but also can be widely applied to various electronic devices that require high density and high reliability. The clear fitting part design simplifies the manufacturing process, reduces the cost, and can flexibly expand the functions of the circuit board 10 according to specific requirements.

[0035] In some embodiments, the first fitting part 1201 on one side of the interconnection board 12 specifically includes a first connecting boss (not shown in the figure), and the third fitting part on one side of a core board 11 connected thereto correspondingly includes a first connecting groove (not shown in the figure). The first connecting boss is used to be embedded into the first connecting groove of the adjacent core board 11 to realize electrical connection and structural connection between one side of the interconnection board 12 and the core board 11.

[0036] And the second fitting part 1202 on the other side of the interconnection board 12 specifically includes a second connecting boss (not shown in the figure), and the fourth fitting part on one side of another core board 11 connected thereto correspondingly includes a second connecting groove (not shown in the figure). The second connecting boss is used to be embedded into the second connecting groove of the adjacent core board 11 to realize electrical connection and structural connection between the other side of the interconnection board 12 and the core board 11, so as to realize electrical connection and structural connection between two adjacent core boards 11 through the interconnection board 12, and the design line logic can also be realized by using the interconnection board 12. By introducing the fitting part design, a stable mechanical connection and a reliable electrical connection can be achieved between adjacent core boards 11, thereby improving the overall performance and reliability of the multi-layer circuit board 10.

[0037] In some embodiments, the interconnection board 12 further specifically includes an insulating layer 121, and a first conductive layer 122 and a second conductive layer 123 disposed on opposite side surfaces of the insulating layer 121.

[0038] Among them, the insulating layer 121 is the core part located at the center of the interconnection board 12, usually made of a material with high insulation, and is used to isolate different conductive layers to prevent short circuits; the first conductive layer 122 is disposed on one side of the insulating layer 121 and includes a first fitting portion 1201 for mechanical and electrical connection with the third fitting portion of the adjacent core board 11; the second conductive layer 123 is disposed on the other side of the insulating layer 121 and includes a second fitting portion 1202 for mechanical and electrical connection with the fourth fitting portion of the adjacent core board 11; the insulating layer 121 is used to provide electrical isolation to ensure that the first conductive layer 122 and the second conductive layer 123 do not come into direct contact, and at the same time support the entire structure of the interconnection board 12.

[0039] In some embodiments, conductive vias are also provided in the insulating layer 121. The conductive vias are small holes passing through the insulating layer 121, and the inside is filled with a conductive material (such as copper), which is used to establish an electrical connection between the first conductive layer 122 and the second conductive layer 123, provide an electrical path from the first conductive layer 122 to the second conductive layer 123, and ensure that current can flow smoothly through the interconnection board 12. Multiple conductive vias can be provided as needed to increase the current-carrying capacity and signal integrity. The design of the conductive vias enables a reliable electrical connection between the first conductive layer 122 and the second conductive layer 123, reduces the contact resistance and signal loss, and improves the performance of the overall circuit.

[0040] Please refer to Figure 2 , Figure 2 , which is a schematic structural diagram of the second embodiment of the circuit board in the present application. The difference between the circuit board in this embodiment and the first embodiment of the circuit board provided in the present application is that the first fitting portion 2201 on one side of the interconnection board 22 in the circuit board 20 specifically includes a fifth connection groove (not shown in the figure) and / or a fifth connection boss (not shown in the figure).

[0041] It can be understood that, in order to realize the connection between different core boards 21, a groove can be specifically provided on the interconnection board 22, and a boss can be provided on the corresponding core board 21, so that by embedding the boss in the groove, the connection between the core boards 21 can be correspondingly realized, and the electrical connection can be realized through each interconnection board 22. Moreover, both a groove and a boss can be provided on the interconnection board 22, and they can cooperate with the fitting structures on the corresponding core boards 21 to effectively utilize each interconnection board 22 to realize the mechanical connection and electrical connection between the core boards 21.

[0042] Specifically, the first fitting portion 2201 on one side of the interconnection board 22 specifically includes a fifth connection groove and / or a fifth connection boss, and the third fitting portion on one side of a core board 21 connected thereto correspondingly includes a sixth connection groove (not shown in the figure) and / or a sixth connection boss (not shown in the figure), corresponding to the first fitting portion 2201. The fifth connection groove is a concave structure for receiving the sixth connection boss from the adjacent core board 21; the fifth connection boss is a convex structure for being embedded into the sixth connection groove of the adjacent core board 21; the sixth connection groove is a concave structure for receiving the fifth connection boss from the interconnection board 22; the sixth connection boss is a convex structure for being embedded into the fifth connection groove of the interconnection board 22.

[0043] When the first fitting portion 2201 includes a fifth connection boss, it will be embedded into the sixth connection groove of the third fitting portion to achieve precise alignment and mechanical fixation. When the third fitting portion includes a sixth connection boss, it will be embedded into the fifth connection groove of the first fitting portion 2201 to equally achieve precise alignment and mechanical fixation. Moreover, while the first fitting portion 2201 realizes structural connection with the third fitting portion, it is also used to electrically connect one side of the interconnection board 22 with the adjacent core board 21.

[0044] The second fitting portion 2202 on the other side of the interconnection board 22 specifically includes a seventh connection groove (not shown in the figure) and / or a seventh connection boss (not shown in the figure), and the fourth fitting portion on one side of the other core board 21 connected thereto correspondingly includes an eighth connection groove (not shown in the figure) and / or an eighth connection boss (not shown in the figure), corresponding to the second fitting portion 2202. The seventh connection groove is a concave structure for receiving the eighth connection boss from the adjacent core board 21; the seventh connection boss is a convex structure for being embedded into the eighth connection groove of the adjacent core board 21; the eighth connection groove is a concave structure for receiving the seventh connection boss from the interconnection board 22; the eighth connection boss is a convex structure for being embedded into the seventh connection groove of the interconnection board 22.

[0045] When the second fitting portion 2202 includes a seventh connection boss, it will be embedded into the eighth connection groove of the fourth fitting portion to achieve precise alignment and mechanical fixation. When the fourth fitting portion includes an eighth connection boss, it will be embedded into the seventh connection groove of the second fitting portion 2202 to equally achieve precise alignment and mechanical fixation. Moreover, while the second fitting portion 2202 realizes structural connection with the fourth fitting portion, it is also used to electrically connect the other side of the interconnection board 22 with the other adjacent core board 21.

[0046] It is understandable that the design of the connection grooves and connection bosses provides multi-point contact, increasing the mechanical strength between the core board 21 and the interconnection board 22 and reducing the risk of delamination caused by vibration or impact. The fitting design not only provides physical support but also enables reliable electrical connection between adjacent core boards 21 by filling the fitting part with a conductive material, reducing contact resistance and signal loss. This design allows for the integration of more circuit layers in a limited space, improving the overall density and functional complexity of the circuit board 20. The clear fitting part design makes the manufacturing process more standardized and controllable, reducing production costs and increasing production efficiency. According to actual requirements, the functions and performance of the circuit board 20 can be flexibly adjusted by increasing or decreasing the number of core board 21 layers, with good scalability.

[0047] In some other embodiments, the first fitting part 2201 on one side of the interconnection board 22 specifically includes a third connection groove (not shown in the figure), and the third fitting part on one side of a core board 21 connected thereto correspondingly includes a third connection boss (not shown in the figure). The third connection boss is used to be embedded in the third connection groove of the adjacent core board 21 to achieve electrical connection and structural connection between one side of the interconnection board 22 and the core board 21.

[0048] And the second fitting part 2202 on the other side of the interconnection board 22 specifically includes a fourth connection groove (not shown in the figure), and the fourth fitting part on one side of another core board 21 connected thereto correspondingly includes a fourth connection boss (not shown in the figure). The fourth connection boss is used to be embedded in the fourth connection groove of the adjacent core board 21 to achieve electrical connection and structural connection between the other side of the interconnection board 22 and the core board 21, so as to achieve electrical connection and structural connection between two adjacent core boards 21 through the interconnection board 22, and the design circuit logic can also be realized by using the interconnection board 22. By introducing the fitting part design, a stable mechanical connection and a reliable electrical connection can be achieved between adjacent core boards 21, thereby improving the overall performance and reliability of the multi-layer circuit board 20.

[0049] In some embodiments, a first conductive adhesive layer 231 is further provided between the first fitting part 2201 of the interconnection board 22 and the third fitting part of an adjacent core board 21, and a second conductive adhesive layer 232 is further provided between the second fitting part 2202 of the interconnection board 22 and the fourth fitting part of another adjacent core board 21, so as to enable the interconnection board 22 to be more closely connected to the two adjacent core boards 21 in terms of structure by using the first conductive adhesive layer 231 and the second conductive adhesive layer 232, and ensure electrical connection at the same time.

[0050] In some embodiments, the first conductive adhesive layer 231 and the second conductive adhesive layer 232 can specifically be any reasonable conductive material with a certain viscosity such as solder paste or copper paste, and the present application does not limit this.

[0051] The present application also provides a method for manufacturing a circuit board. Please refer to Figure 3 , Figure 3 which is a schematic flowchart of an embodiment of the method for manufacturing the circuit board of the present application. This embodiment includes the following steps:

[0052] S31: Provide at least two core boards.

[0053] Wherein, each core board can specifically be a single-layer patterned copper clad laminate, or can include at least two layers of patterned copper clad laminates. And between every two adjacent copper clad laminates of the at least two copper clad laminates, an insulating dielectric layer is stacked, and connection is achieved through metal vias arranged in the insulating dielectric layer; and the inner core board can specifically further include passive components, such as any reasonable circuit elements like capacitors, resistors, etc., and / or one or more of other any reasonable materials that can be used for manufacturing circuit boards, such as copper plates, electroplated copper layers, conductive posts, heat dissipation plates, thermal conductive adhesives, etc., so as to be able to realize the pre-designed circuit logic through the patterned copper clad laminate, that is, the conductive circuit layer, and circuit units such as conductive posts and buried components. The present application does not make any limitations thereto.

[0054] It can be understood that the high-density interconnect board intended to be manufactured can specifically be split into at least two sub-boards with fewer layers, that is, core boards, for separate manufacturing.

[0055] S32: Provide an interconnect board between every two adjacent core boards.

[0056] Furthermore, corresponding to the designed circuit logic and outer shape structure of each core board, manufacture the corresponding number of interconnect boards, so as to provide an interconnect board between every two adjacent core boards, and stack the core boards through this interconnect board, and achieve structural connection and electrical connection.

[0057] Wherein, a first fitting portion and a second fitting portion are respectively provided on opposite side surfaces of each interconnect board, and a third fitting portion and a fourth fitting portion are respectively provided on each core board corresponding to the first fitting portion and the second fitting portion.

[0058] The first fitting portion is provided on one side of the interconnect board facing a core board connected thereto, for fitting into the third fitting portion on this core board; the second fitting portion is provided on one side of the interconnect board facing another core board connected thereto, for fitting into the fourth fitting portion on this core board; the third fitting portion is provided on the adjacent core board, corresponding to the first fitting portion of the interconnect board, to ensure precise fitting between the two; the fourth fitting portion is provided on the other adjacent core board, corresponding to the second fitting portion of the interconnect board, to ensure precise fitting between the two.

[0059] Through the fitting design of the first fitting part, the second fitting part, the third fitting part and the fourth fitting part, the mechanical strength between the core board and the interconnection board is increased, the delamination risk caused by vibration or impact is reduced, and the mechanical stability is enhanced. The fitting design not only provides physical support, but also can fill the fitting part with a conductive material (such as copper) to achieve reliable electrical connection between adjacent core boards, reduce contact resistance and signal loss, and improve the reliability of electrical connection. By integrating more circuit layers in a limited space, the overall density and functional complexity of the circuit board are improved, and the space utilization rate is optimized. The clear fitting part design makes the manufacturing process more standardized and controllable, reduces production costs and improves production efficiency.

[0060] S33: Laminate each core board and each interconnection board of the stacked arrangement to obtain a circuit board.

[0061] Furthermore, through the lamination process, each core board and each interconnection board of the stacked arrangement are laminated to tightly combine multiple core boards and interconnection boards together to form a solid overall structure to obtain a circuit board, while ensuring the reliability of electrical connection and mechanical strength.

[0062] Further, in an embodiment, after the above S31 and before S32, specifically, it further includes: taking at least two provided core boards as N (N is a positive integer) layer boards and M layer boards (M is a positive integer) as an example, on the N layer board, a prepreg is pasted on the surface to be interconnected, and the prepreg is prevented from being completely cured; on the M layer board, a prepreg is pasted on the surface to be interconnected, and the prepreg is prevented from being completely cured; use a laser drill to ablate the prepreg on the N layer board and the M layer board at the positions of the pads that need to connect the upper and lower layers with the laser drill, and burn out laser holes; screen-print solder paste or copper paste at the positions of the laser holes in the N layer board and the M layer board; tear off the protective film on the prepreg.

[0063] It can be understood that the first fitting part and the second fitting part of the interconnection board specifically correspond to the positions where the solder paste or copper paste is screen-printed in the N layer board and the M layer board to achieve structural connection and electrical connection therewith.

[0064] In the above solution, by splitting the multi-level HDI board parts into multiple sub-boards with fewer levels, that is, at least two core boards, and realizing the embedded connection between different core boards through the interconnection board, the interconnection density is significantly improved, the number of lamination times in the manufacturing process can be effectively reduced, the process flow is simplified, and the reliability is also relatively high, thereby effectively improving production efficiency and product quality.

[0065] Please refer to Figure 4 , Figure 4 Yes Figure 3 is a schematic flowchart of an embodiment corresponding to S32 in

[0066] In one embodiment, step S32 may specifically further include the following steps:

[0067] S321: Provide a substrate and form conductive vias on the substrate.

[0068] Among them, the substrate may specifically be a single-sided copper clad laminate, or may include at least two patterned copper clad laminates, and an insulating dielectric layer is stacked between every two adjacent copper clad laminates of the at least two copper clad laminates, and connections are achieved through metal vias provided in the insulating dielectric layer; and the inner core board may specifically further include passive components, such as any reasonable circuit elements such as capacitors and resistors, and / or one or more of other any reasonable materials that can be used for manufacturing circuit boards, such as copper plates, electroplated copper layers, conductive posts, heat dissipation plates, thermal conductive adhesives, etc., so as to be able to realize the pre-designed circuit logic through the patterned copper clad laminate, that is, the conductive circuit layer, and circuit units such as conductive posts and buried components. This application does not make any limitations in this regard.

[0069] Specifically, conductive vias are opened on the substrate by processes such as drilling and etching.

[0070] S322: Form a first conductive layer and a second conductive layer on opposite sides of the substrate respectively to obtain an interconnection board.

[0071] Successively form a first conductive layer and a second conductive layer on opposite sides of the substrate respectively by one or more of any reasonable process steps such as etching, exposure, development, and graphic electroplating to obtain an interconnection board.

[0072] Among them, the first conductive layer is connected to the second conductive layer through the conductive vias, a first fitting portion is provided in the first conductive layer, and a second fitting portion is provided in the second conductive layer.

[0073] In some embodiments, the first fitting portion on one side of the interconnection board specifically includes a first connection boss, and the third fitting portion on one side of a core board connected thereto correspondingly includes a first connection groove. The first connection boss is used to be embedded into the first connection groove of the adjacent core board to achieve electrical connection and structural connection between one side of the interconnection board and the core board.

[0074] And the second fitting portion on the other side of the interconnection board specifically includes a second connection boss, and the fourth fitting portion on one side of another core board connected thereto correspondingly includes a second connection groove. The second connection boss is used to be embedded into the second connection groove of the adjacent core board to achieve electrical connection and structural connection between the other side of the interconnection board and the core board, so as to achieve electrical connection and structural connection between two adjacent core boards through the interconnection board, and the designed circuit logic can also be realized by using the interconnection board. By introducing the fitting portion design, a stable mechanical connection and a reliable electrical connection can be achieved between adjacent core boards, thereby improving the overall performance and reliability of the multi-layer circuit board.

[0075] In some embodiments, the first fitting portion on one side of the interconnection board specifically includes a third connection groove, and the third fitting portion on one side of a core board connected thereto correspondingly includes a third connection boss, which is used to be embedded into the third connection groove of the adjacent core board to achieve electrical connection and structural connection between one side of the interconnection board and the core board.

[0076] And the second fitting portion on the other side of the interconnection board specifically includes a fourth connection groove, and the fourth fitting portion on one side of the other core board connected thereto correspondingly includes a fourth connection boss, which is used to be embedded into the fourth connection groove of the adjacent core board to achieve electrical connection and structural connection between the other side of the interconnection board and the core board, so as to achieve electrical connection and structural connection between two adjacent core boards through the interconnection board, and the design circuit logic can also be realized by using the interconnection board. By introducing the fitting portion design, a stable mechanical connection and a reliable electrical connection can be achieved between adjacent core boards, thereby improving the overall performance and reliability of the multi-layer circuit board.

[0077] In some embodiments, the first fitting portion on one side of the interconnection board specifically includes a fifth connection groove and / or a fifth connection boss, and the third fitting portion on one side of a core board connected thereto correspondingly includes a sixth connection groove and / or a sixth connection boss, corresponding to the first fitting portion. The fifth connection groove is a concave structure for receiving the sixth connection boss from the adjacent core board; the fifth connection boss is a convex structure for being embedded into the sixth connection groove of the adjacent core board; the sixth connection groove is a concave structure for receiving the fifth connection boss from the interconnection board; the sixth connection boss is a convex structure for being embedded into the fifth connection groove of the interconnection board.

[0078] When the first fitting portion includes a fifth connection boss, it will be embedded into the sixth connection groove of the third fitting portion to achieve precise alignment and mechanical fixation. When the third fitting portion includes a sixth connection boss, it will be embedded into the fifth connection groove of the first fitting portion to also achieve precise alignment and mechanical fixation. And while the first fitting portion realizes structural connection with the third fitting portion, it is also used to achieve electrical connection between one side of the interconnection board and the adjacent core board.

[0079] The second fitting portion on the other side of the interconnection board specifically includes a seventh connection groove and / or a seventh connection boss, and the fourth fitting portion on one side of the other core board connected thereto correspondingly includes an eighth connection groove and / or an eighth connection boss, corresponding to the second fitting portion. The seventh connection groove is a concave structure for receiving the eighth connection boss from the adjacent core board; the seventh connection boss is a convex structure for being embedded into the eighth connection groove of the adjacent core board; the eighth connection groove is a concave structure for receiving the seventh connection boss from the interconnection board; the eighth connection boss is a convex structure for being embedded into the seventh connection groove of the interconnection board.

[0080] When the second fitting part includes the seventh connecting boss, it will be embedded into the eighth connecting groove of the fourth fitting part to achieve precise alignment and mechanical fixation. When the fourth fitting part includes the eighth connecting boss, it will be embedded into the seventh connecting groove of the second fitting part to also achieve precise alignment and mechanical fixation. Moreover, while the second fitting part realizes structural connection with the fourth fitting part, it is also used to electrically connect the other side of the interconnection board to another adjacent core board.

[0081] Please refer to Figure 5a - Figure 5l , wherein, Figure 5a is Figure 3 a schematic flow diagram of another embodiment corresponding to S32 in Figure 5b - Figure 5l is Figure 5a a schematic structural diagram of an embodiment corresponding to S3211 - S3212 in

[0082] S3211: Provide a substrate, and successively perform drilling, etching, flash plating, film laminating, primary exposure and development, and pattern electroplating on the substrate to form conductive vias on the substrate.

[0083] Specifically, as Figure 5b - Figure 5h shown, taking the provided substrate 41 as a copper clad laminate, with the surface copper 412 of the copper clad laminate having a thickness of 3 - 5 um (micrometers) and the dielectric layer 411 having a thickness of 0.05 mm - 0.2 mm (millimeters) as an example, it can be known that the manufacturing process of the substrate 41 can specifically be as follows successively:

[0084] Laser drilling: Drill X vias with a hole diameter of about 50 um;

[0085] Etching: Etch the substrate;

[0086] Plasma desmear: Electrochemically remove the resin on the surface of the substrate to roughen the surface of the substrate, increase the surface roughness of the substrate, and enhance the bonding force between the copper surface and the substrate;

[0087] Flash plating: Flash plate about 1 um of electroplated copper 42. The purpose is 1. To metallize the X vias by flash plating to facilitate subsequent pattern electroplating conduction electroplating; among them, flash plating 1 um of bottom copper helps to etch and make small hole pads after pattern thickening;

[0088] Film laminating: Laminate dry film 43;

[0089] Exposure / development: Pattern transfer, expose and develop the pattern area to be bare, prepare for pattern thickening electroplating, the hole pads can be made 80 um, and the pitch is 20 um, that is, a hole pitch of 0.1 mm;

[0090] Pattern electroplating: Fill the X vias with copper, thereby forming conductive vias 44 on the substrate 41.

[0091] S3212: The substrate after pattern electroplating is successively subjected to wet film printing, secondary exposure and development, electroplating, film stripping, and flash etching to form a first conductive layer and a second conductive layer on the opposite side surfaces of the substrate respectively, so as to obtain an interconnected board.

[0092] Further, as Figure 5i - Figure 5l shown, the substrate 41 after pattern electroplating is successively subjected to the following processes:

[0093] Wet film printing: Screen-print a wet film 45 resistant to electroplating;

[0094] Exposure / development: Open small windows on the pads, expose and develop them, aiming to form a copper pillar 46 on the via pads;

[0095] Pattern electroplating: Electroplate another copper pillar 46 with a convex platform on the via pads to form a convex platform copper pillar 46 of 30 um;

[0096] Film stripping: Remove the dry film 43 and the wet film 45 together;

[0097] Flash etching: Quickly etch away about 1 um of the bottom copper to form an arbitrary interconnected structure with pad copper pillars, that is, a first conductive layer and a second conductive layer are respectively formed on the opposite side surfaces of the substrate 41 to obtain an interconnected board.

[0098] This application also provides an electronic device. Please refer to Figure 6 , Figure 6 which is a schematic structural diagram of an embodiment of the electronic device of this application. In this embodiment, the electronic device 50 includes a housing 51 and a circuit board 52 connected to each other.

[0099] It should be noted that the circuit board 52 described in this embodiment is the circuit board 10 or the circuit board 20 as described in any one of the above, and for details, please refer to Figure 1 , Figure 2 and the relevant text content, which will not be elaborated here.

[0100] The beneficial effects of this application are as follows: Different from the prior art, in the circuit board provided by this application, an interconnected board is provided between every two adjacent core boards. The interconnected board is respectively provided with a first fitting part and a second fitting part on the opposite sides facing the two adjacent core boards connected thereto. The two adjacent core boards are respectively provided with a third fitting part and a fourth fitting part corresponding to the first fitting part and the second fitting part. The first fitting part is fitted into the third fitting part, and the second fitting part is fitted into the fourth fitting part to connect the two adjacent core boards. Thus, a multi-level HDI board can be split into multiple sub-boards with fewer levels, that is, at least two core boards, and the embedded connection between different core boards can be realized through the interconnected board, thereby significantly improving the interconnection density, effectively reducing the number of lamination times in the manufacturing process, simplifying the process flow, and having relatively high reliability, so as to effectively improve the production efficiency and product quality.

[0101] The above are only the implementation manners of this application, and do not thus limit the patent scope of this application. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of this application, or directly or indirectly applied in other related technical fields, shall similarly be included within the patent protection scope of this application.

Claims

1. A circuit board, characterized in that, The circuit board includes: At least two core boards arranged in a stacked manner, and an interconnection board is provided between every two adjacent core boards; Wherein, the interconnection board is provided with a first fitting portion and a second fitting portion on opposite sides facing two adjacent core boards connected thereto, and the two adjacent core boards are respectively provided with a third fitting portion and a fourth fitting portion corresponding to the first fitting portion and the second fitting portion, the first fitting portion is fitted into the third fitting portion, and the second fitting portion is fitted into the fourth fitting portion to connect the two adjacent core boards.

2. The circuit board according to claim 1, wherein The first fitting portion includes a first connecting boss, and the third fitting portion correspondingly includes a first connecting groove, and the first connecting boss is fitted into the first connecting groove; The second fitting portion includes a second connecting boss, and the fourth fitting portion correspondingly includes a second connecting groove, and the second connecting boss is fitted into the second connecting groove.

3. The circuit board according to claim 1, wherein The first fitting portion includes a third connecting groove, and the third fitting portion correspondingly includes a third connecting boss, and the third connecting boss is fitted into the third connecting groove; The second fitting portion includes a fourth connecting groove, and the fourth fitting portion correspondingly includes a fourth connecting boss, and the fourth connecting boss is fitted into the fourth connecting groove.

4. The circuit board according to claim 1, wherein The first fitting portion includes a fifth connecting groove and / or a fifth connecting boss, and the third fitting portion correspondingly includes a sixth connecting groove and / or a sixth connecting boss, the fifth connecting boss is fitted into the sixth connecting groove, and the sixth connecting boss is fitted into the fifth connecting groove; The second fitting portion includes a seventh connecting groove and / or a seventh connecting boss, and the fourth fitting portion correspondingly includes an eighth connecting groove and / or an eighth connecting boss, the seventh connecting boss is fitted into the eighth connecting groove, and the eighth connecting boss is fitted into the seventh connecting groove.

5. The circuit board according to any one of claims 1-4, wherein The interconnection board includes an insulating layer and a first conductive layer and a second conductive layer provided on opposite sides of the insulating layer, the first fitting portion is provided in the first conductive layer, and the second fitting portion is provided in the second conductive layer.

6. The circuit board according to claim 5, wherein A conductive through hole is further provided in the insulating layer, and the first conductive layer is connected to the second conductive layer through the conductive through hole.

7. A manufacturing method of a circuit board, characterized in that, The manufacturing method of the circuit board includes: Providing at least two core boards; Arranging an interconnection board between every two adjacent core boards; wherein, the interconnection board is provided with a first fitting portion and a second fitting portion on opposite sides facing two adjacent core boards connected thereto, and the two adjacent core boards are respectively provided with a third fitting portion and a fourth fitting portion corresponding to the first fitting portion and the second fitting portion, the first fitting portion is fitted into the third fitting portion, and the second fitting portion is fitted into the fourth fitting portion to connect the two adjacent core boards; Laminating the stacked core boards and the interconnection boards to obtain the circuit board.

8. The manufacturing method of the circuit board according to claim 7, characterized in that, After the step of providing at least two core boards, before the step of disposing an interconnection board between every two adjacent core boards, the method further includes: providing a substrate and forming conductive vias on the substrate; forming a first conductive layer and a second conductive layer on opposite side surfaces of the substrate respectively to obtain the interconnection board; wherein, the first conductive layer is connected to the second conductive layer through the conductive vias, a first fitting portion is provided in the first conductive layer, and a second fitting portion is provided in the second conductive layer.

9. The manufacturing method of the circuit board according to claim 8, characterized in that, The step of providing a substrate and forming conductive vias on the substrate includes: providing a substrate, and sequentially performing drilling, etching, flash plating, film laminating, first exposure and development, and pattern electroplating on the substrate to form conductive vias on the substrate; The step of forming a first conductive layer and a second conductive layer on opposite side surfaces of the substrate respectively includes: performing wet film printing, second exposure and development, electroplating, film stripping, and flash etching on the substrate after pattern electroplating to form a first conductive layer and a second conductive layer on opposite side surfaces of the substrate respectively.

10. An electronic device, characterized in that, The electronic device includes a housing and a circuit board which are connected to each other; wherein, the circuit board is the circuit board according to any one of claims 1-6.

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