Preparation method of circuit board and circuit board
By forming patterned grooves on a conductive metal substrate and embedding conductive patterned bumps, the problem of insufficient adhesion between the copper block and the substrate is solved, thereby improving the reliability of the copper embedding process and the product yield.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- NANTONG SHENNAN CIRCUIT CO LTD
- Filing Date
- 2026-01-05
- Publication Date
- 2026-04-17
AI Technical Summary
In existing technologies, the bonding force between the copper block and the substrate is insufficient, and it is prone to displacement during the lamination process, resulting in abnormal continuity of internal circuits and reducing the reliability of the copper embedding process and product yield.
By forming patterned grooves on a conductive metal substrate and embedding conductive patterned bumps in the metallized grooves of the substrate to be treated, the bonding force is improved by utilizing the interlocking effect of the patterned grooves and conductive patterned bumps.
It improves the embedding stability of conductive metal substrates, enhancing the reliability of copper embedding processes and product yield.
Smart Images
Figure CN121888486A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of circuit board processing technology, and in particular to methods for preparing circuit boards and circuit boards themselves. Background Technology
[0002] With the development of 5G and microelectronics technologies, the application of high-frequency PCBs (Printed Circuit Boards) is becoming increasingly widespread. The higher the power consumption inside a high-frequency PCB, the greater the demand for heat dissipation.
[0003] In related technologies, local copper embedding is commonly used to improve the heat dissipation performance of PCBs. This involves embedding copper blocks in the area where high-power devices are located to dissipate heat from the high-power devices, thereby improving the stability and lifespan of the equipment.
[0004] However, due to insufficient bonding force between the copper block and the substrate, the copper block is prone to displacement during the lamination process, resulting in abnormal continuity of internal circuits, which reduces the reliability of the copper embedding process and consequently reduces product yield. Summary of the Invention
[0005] The main technical problem addressed by this application is to provide a method for fabricating a circuit board and the circuit board itself, which can solve the problem that related technologies cannot improve the stability of metal substrate embedding.
[0006] To solve the above-mentioned technical problems, the first technical solution adopted in this application is to provide a method for manufacturing a circuit board, including: obtaining a conductive metal substrate with patterned grooves on its surface; obtaining a board material to be processed with metallized grooves on its surface; wherein, conductive patterned bumps are provided at the bottom of the metallized grooves, and the conductive patterned bumps correspond to the patterned grooves; the size of the metallized grooves is greater than or equal to the size of the conductive metal substrate; placing the conductive metal substrate in the metallized grooves of the board material to be processed, and making the patterned grooves and conductive patterned bumps fit together.
[0007] The step of obtaining a substrate with metallized grooves on its surface includes: obtaining a substrate to be processed; wherein the thickness of the substrate to be processed is greater than the height of the conductive metal base, and the cross-sectional dimension of the substrate to be processed is greater than the cross-sectional dimension of the conductive metal base; performing controlled-depth milling on the substrate to be processed based on the dimensions of the conductive metal base until the bottom of the controlled-depth groove is an insulating dielectric layer with a preset thickness; wherein the depth of the controlled-depth groove is less than the height of the conductive metal base, and the sum of the preset thickness of the insulating dielectric layer and the depth of the controlled-depth groove is greater than or equal to the height of the conductive metal base; performing laser ablation on the insulating dielectric layer based on the morphology of the patterned grooves to form patterned bumps in the remaining insulating dielectric layer; and performing copper plating followed by electroplating on the substrate to be processed to obtain conductive patterned bumps and metallized grooves, thereby obtaining the substrate to be processed; wherein the depth of the metallized grooves is greater than or equal to the height of the conductive metal base.
[0008] The step of obtaining the material to be processed includes: obtaining a high-frequency material core board; wherein the high-frequency material core board has a first surface and a second surface arranged opposite to each other; the cross-sectional dimension of the high-frequency material core board is larger than the cross-sectional dimension of the conductive metal substrate; pressing a pre-set semi-cured sheet and a single-layer core board onto the first surface of the high-frequency material core board, and pressing a pre-set semi-cured sheet and a single-layer core board onto the second surface of the high-frequency material core board; wherein the thickness of the pre-set semi-cured sheet is greater than that of the semi-cured sheet; continuing to press a pre-set semi-cured sheet and a single-layer core board onto at least the first surface of the high-frequency material core board until the height difference between the surface of the outermost core board on the first surface and the first surface is greater than or equal to the height of the conductive metal substrate, and then stopping the layering to obtain the material to be processed.
[0009] The step of controlling the depth of the material to be processed based on the dimensions of the conductive metal substrate until the bottom of the controlled depth groove is an insulating dielectric layer with a certain thickness includes: slotting the material to be processed based on the cross-sectional dimensions of the conductive metal substrate; controlling the depth of the material to be processed based on the height of the conductive metal substrate, milling to the interior of the preset prepreg, until the preset prepreg has only a preset thickness remaining; wherein the preset thickness is 50~100 micrometers.
[0010] The step of laser ablation of the insulating dielectric layer based on the morphology of the patterned grooves to form patterned bumps in the remaining insulating dielectric layer includes: ablation of the insulating dielectric layer based on the distribution of multiple grooves in the patterned grooves and the cross-sectional dimensions of the multiple grooves, removing part of the insulating dielectric layer until the first surface of the high-frequency material core board is exposed, and forming patterned bumps in the remaining insulating dielectric layer; wherein the first surface of the high-frequency material core board is the bottom of the metallized groove.
[0011] The step of controlling the depth of the material to be processed based on the size of the conductive metal base until the bottom of the controlled depth groove is an insulating dielectric layer with a preset thickness further includes: drilling holes in the material to be processed to obtain at least one hole; and electroplating the material to be processed after copper plating to obtain conductive patterned bumps and metallized grooves to obtain the material to be processed. The step further includes: forming a conductive film on the hole wall by copper plating, and then forming a conductive layer on the conductive film by electroplating to obtain a metallized hole.
[0012] The step of obtaining a conductive metal substrate with patterned grooves on its surface includes: obtaining a metal substrate to be processed; performing controlled-depth milling on one side of the surface of the metal substrate to be processed based on a preset pattern to form patterned grooves, thereby obtaining a conductive metal substrate.
[0013] The step of placing the conductive metal substrate in the metallized groove of the substrate to be treated and fitting the patterned groove with the conductive patterned bump includes filling the gap between the conductive metal substrate and the conductive patterned bump with a conductive adhesive.
[0014] The step of filling the gap between the conductive metal base and the conductive patterned bumps with conductive adhesive includes: preparing a circuit pattern on the side surface of the board to be processed where the conductive metal base is embedded, and forming a solder resist layer on the outer surface of the circuit pattern to obtain a circuit board.
[0015] To solve the above-mentioned technical problems, the second technical solution adopted in this application is to provide a circuit board, which is manufactured by the above-mentioned circuit board preparation method; wherein, the circuit board includes a metallized groove, and a conductive patterned bump is provided at the bottom of the metallized groove, and the conductive patterned bump is fitted and connected to a conductive metal base with a patterned groove on its surface.
[0016] The beneficial effects of this application are as follows: Unlike the prior art, this application provides a method for manufacturing a circuit board and a circuit board. By obtaining a conductive metal substrate with patterned grooves on its surface and a substrate to be processed with metallized grooves on its surface, and a conductive patterned bump is provided at the bottom of the metallized groove, the conductive patterned bump corresponds to the patterned groove, and the conductive metal substrate is placed in the metallized groove of the substrate to be processed, and the patterned groove and the conductive patterned bump are fitted together, the bonding force between the conductive metal substrate and the substrate to be processed can be improved through the fitting effect between the patterned groove and the conductive patterned bump, so as to reduce the probability of the conductive metal substrate shifting, thereby improving the embedding stability of the conductive metal substrate, and thus improving the reliability of the copper embedding process and the product yield. Attached Figure Description
[0017] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0018] Figure 1 This is a schematic flowchart of the first embodiment of the method for manufacturing the circuit board of this application; Figure 2 This is a schematic flowchart of the second embodiment of the method for manufacturing the circuit board of this application; Figure 3 This is a top view of one embodiment of the conductive metal substrate obtained in S22; Figure 4 This is a schematic diagram of the structure of the sheet material to be processed obtained in S23 according to one embodiment; Figure 5 This is a schematic diagram of the structure of the sheet material to be processed obtained in S24 according to one embodiment; Figure 6 This is a schematic diagram of the structure of one embodiment of the plate to be processed obtained in S25; Figure 7 This is a schematic diagram of the structure of the plate to be processed obtained in S26 according to one embodiment; Figure 8 This is a schematic diagram of the structure of the plate material to be processed obtained in S27 according to one embodiment; Figure 9 This is a schematic diagram of one embodiment of the circuit board of this application. Detailed Implementation
[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0020] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to limit the application. The singular forms “a,” “said,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms, unless otherwise clearly indicated above. “Multiple” generally includes at least two, but does not exclude the inclusion of at least one.
[0021] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.
[0022] It should be understood that the terms "comprising," "including," or any other variations used herein are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.
[0023] In related technologies, local copper embedding is commonly used to improve the heat dissipation performance of PCBs. This involves embedding copper blocks in the area where high-power devices are located to dissipate heat from the high-power devices, thereby improving the stability and lifespan of the equipment.
[0024] However, due to insufficient bonding force between the copper block and the substrate, the copper block is prone to displacement during the lamination process, resulting in abnormal continuity of internal circuits, which reduces the reliability of the copper embedding process and consequently reduces product yield.
[0025] Based on the above, this application provides a method for manufacturing a circuit board and a circuit board that can solve the problem that related technologies cannot improve the stability of metal substrate embedding.
[0026] The present application will now be described in detail with reference to the accompanying drawings and embodiments.
[0027] Please see Figure 1 , Figure 1 This is a schematic flowchart of the first embodiment of the circuit board fabrication method of this application. In this embodiment, the fabrication method includes: S11: Obtain a conductive metal substrate with patterned grooves on its surface.
[0028] In this embodiment, the conductive metal substrate includes a copper block.
[0029] In some embodiments, the conductive metal substrate is a cube with a preset length, width and height, and its cross-section is rectangular, with the cross-sectional dimensions being the length and width.
[0030] In this embodiment, the patterned groove includes multiple grooves arranged in a preset pattern.
[0031] In some implementations, multiple groove arrays are distributed on the surface of a conductive metal substrate.
[0032] In some implementations, multiple grooves have the same dimensions. Here, the dimensions of a groove refer to its cross-sectional dimensions and its depth.
[0033] In some specific implementations, the groove is rectangular, and the cross-sectional dimensions are the length and width.
[0034] In other specific embodiments, the groove is circular, and the cross-sectional dimension is the radius.
[0035] S12: Obtain a substrate with a metallized groove on its surface; wherein, a conductive patterned bump is provided at the bottom of the metallized groove, and the conductive patterned bump corresponds to the patterned groove; the size of the metallized groove is greater than or equal to the size of the conductive metal base.
[0036] In this embodiment, the size of the metallized groove being greater than or equal to the size of the conductive metal base means that the cross-sectional size of the metallized groove is equal to the cross-sectional size of the conductive metal base, or the cross-sectional size of the metallized groove is slightly larger than the cross-sectional size of the conductive metal base, and the depth of the metallized groove is equal to the height of the conductive metal base, or the depth of the metallized groove is slightly larger than the height of the conductive metal base.
[0037] Understandably, the size of the metallized groove must be greater than or equal to the size of the conductive metal base in order to accommodate the conductive metal base through the metallized groove.
[0038] In this embodiment, a conductive layer is formed on the sidewall of the metallized groove.
[0039] Understandably, since both the conductive metal base and the conductive layer are metals, the interface difference between the conductive metal base and the metallized groove is small, and the interface thermal resistance is also small, which is beneficial to improving the heat transfer efficiency.
[0040] In this embodiment, the conductive patterned bumps are patterned insulating dielectric layers with a conductive layer on their surface.
[0041] In some implementations, conductive patterned bumps are disposed on a high-frequency material core plate, that is, the bottom of the metallized groove is a high-frequency material core plate.
[0042] Understandably, by setting conductive patterned bumps on the high-frequency material core board, the high-frequency material core board can be cooled by the subsequently embedded conductive metal substrate, thereby meeting the heat dissipation requirements of high-frequency PCBs.
[0043] In this embodiment, the height of the conductive patterned bump can be equal to the depth of the patterned groove, or slightly greater or slightly less than the depth of the patterned groove.
[0044] Understandably, the height of the conductive patterned bump is equal to that of the patterned groove, which enables the conductive patterned bump and the patterned groove to form a zero-gap fit, thereby improving the fit accuracy and fit stability.
[0045] Understandably, the height of the conductive patterned bump is slightly larger or slightly smaller than the patterned groove, which allows the conductive patterned bump and the patterned groove to form a gap fit, thereby reducing the processing difficulty of the conductive patterned bump and the patterned groove.
[0046] S13: Place the conductive metal base in the metallized groove of the plate to be treated, and make the patterned groove fit into the conductive patterned bump.
[0047] In this embodiment, the engagement between the patterned groove and the conductive patterned bump depends on the depth of the patterned groove and the height of the conductive patterned bump.
[0048] In some implementations, if the height of the conductive patterned bump is equal to the depth of the patterned groove, the conductive patterned bump and the patterned groove are fully engaged, that is, the top of the conductive patterned bump contacts the bottom of the patterned groove, and the bottom of the conductive patterned bump contacts the surface of the patterned groove.
[0049] In other embodiments, the height of the conductive patterned bump is slightly greater than the depth of the patterned groove, so that most of the conductive patterned bump is embedded in the patterned groove, that is, the top of the conductive patterned bump contacts the bottom of the patterned groove, and a small gap is left between the bottom of the conductive patterned bump and the surface of the patterned groove.
[0050] In some other embodiments, the height of the conductive patterned bump is slightly less than the depth of the patterned groove, so that the conductive patterned bump is completely embedded in the patterned groove, that is, the bottom of the conductive patterned bump is in contact with the surface of the patterned groove, and a small gap is left between the top of the conductive patterned bump and the bottom of the patterned groove.
[0051] Understandably, by making the patterned grooves and conductive patterned bumps fit together well, the bonding force between the conductive metal substrate and the substrate to be treated can be greatly improved.
[0052] Unlike related technologies, this embodiment obtains a conductive metal substrate with patterned grooves on its surface and a substrate to be processed with metallized grooves on its surface. Conductive patterned bumps are provided at the bottom of the metallized grooves, and the conductive patterned bumps correspond to the patterned grooves. The conductive metal substrate is placed in the metallized grooves of the substrate to be processed, and the patterned grooves and conductive patterned bumps are fitted together. The bonding force between the conductive metal substrate and the substrate to be processed can be improved through the fitting effect between the patterned grooves and the conductive patterned bumps, thereby reducing the probability of conductive metal substrate displacement, improving the embedding stability of the conductive metal substrate, and thus improving the reliability of the copper embedding process and the product yield.
[0053] Please see Figure 2 , Figure 2 This is a schematic flowchart of a second embodiment of the method for fabricating the circuit board according to this application. In this embodiment, the fabrication method includes: S21: Obtain the metal substrate to be processed.
[0054] In this embodiment, the metal substrate to be processed is a cubic copper block with a preset length, width and height.
[0055] S22: Based on a preset pattern, perform controlled-depth milling on one side of the surface of the metal substrate to be processed to form a patterned groove, thereby obtaining a conductive metal substrate.
[0056] In this embodiment, the preset pattern refers to multiple regular patterns arranged in an array.
[0057] The regular shapes can be rectangles, circles, or triangles.
[0058] In this embodiment, the patterned groove includes multiple grooves arranged in a preset pattern.
[0059] In some implementations, multiple grooves are arranged in an array.
[0060] In this embodiment, the multiple grooves are of the same size.
[0061] In some implementations, the multiple grooves are all rectangular and have the same depth.
[0062] In some implementations, the depth of the multiple grooves is 50 to 100 micrometers.
[0063] Specifically, please refer to Figure 3 , Figure 3 This is a top view of one embodiment of the conductive metal substrate obtained in S22.
[0064] In this embodiment, one side surface of the conductive metal substrate 10 includes patterned grooves, which include a plurality of grooves 16 arranged in an array. The depth of the grooves 16 is 80 micrometers.
[0065] S23: Obtain the material to be processed; wherein the thickness of the material to be processed is greater than the height of the conductive metal base, and the cross-sectional dimensions of the material to be processed are greater than the cross-sectional dimensions of the conductive metal base.
[0066] In this embodiment, a high-frequency material core board is first obtained. The high-frequency material core board has a first surface and a second surface disposed opposite to each other, and the cross-sectional dimension of the high-frequency material core board is larger than the cross-sectional dimension of the conductive metal substrate.
[0067] The high-frequency material core board has circuit patterns on its first and second surfaces.
[0068] In this high-frequency material core board, the first and second surfaces are copper foil layers, and the space between the first and second surfaces is a dielectric layer.
[0069] Furthermore, a pre-prepared semi-cured sheet and a single-layer core board are pressed onto the first surface of the high-frequency material core board, and a pre-prepared semi-cured sheet and a single-layer core board are pressed onto the second surface of the high-frequency material core board. The thickness of the pre-prepared semi-cured sheet is greater than that of the pre-prepared semi-cured sheet.
[0070] The thickness of the pre-cured sheet ranges from 120 micrometers to 200 micrometers.
[0071] Furthermore, at least on the first surface of the high-frequency material core board, the prepreg and the single-layer core board are pressed together until the height difference between the surface of the outermost core board on the first surface and the first surface is greater than or equal to the height of the conductive metal base. Then, the layering is stopped to obtain the board to be processed.
[0072] The single-layer core board includes a dielectric layer and copper layers disposed on both sides of the dielectric layer.
[0073] Understandably, continuing to press the prepreg and single-layer core board onto the first surface of the high-frequency material core board until the height difference between the surface of the outermost core board on the first surface and the first surface is greater than or equal to the height of the conductive metal base can ensure that the depth of the subsequently formed metallized groove is greater than or equal to the height of the conductive metal base.
[0074] In some implementations, a prepreg and a single-layer core board can be further laminated onto the second surface of the high-frequency material core board to obtain the required number of layers.
[0075] Specifically, please refer to Figure 4 , Figure 4 This is a schematic diagram of one embodiment of the material to be processed obtained in S23.
[0076] In this embodiment, the substrate 100 to be processed includes a high-frequency material core board 20 and multilayer core boards 11 disposed on both sides of the high-frequency material core board 20. Each core board 11 includes a dielectric layer 13 and copper layers 14 disposed on both sides of the dielectric layer 13. The high-frequency material core board 20 includes a first surface 21 and a second surface 22 disposed opposite to each other. The first surface 21 and the second surface 22 are copper foil layers, and the dielectric layer 13 is located between the first surface 21 and the second surface 22. The first surface 21 is bonded to adjacent core boards 11 by a pre-set prepreg 30, and the second surface 22 is bonded to adjacent core boards 11 by a prepreg 12. Adjacent core boards 11 are bonded together by prepreg 12. The thickness of the pre-set prepreg 30 is greater than the thickness of the prepreg 12. Specifically, the thickness of the pre-set prepreg 30 is 150 micrometers. The height difference between one outer surface 101 of the substrate 100 and the first surface 21 of the high-frequency material core board 20 is equal to the thickness of the conductive metal substrate 10.
[0077] S24: Based on the dimensions of the conductive metal base, perform controlled depth milling on the material to be processed until the bottom of the controlled depth groove is an insulating dielectric layer with a preset thickness; wherein, the depth of the controlled depth groove is less than the height of the conductive metal base, and the sum of the preset thickness of the insulating dielectric layer and the depth of the controlled depth groove is greater than or equal to the height of the conductive metal base.
[0078] In this embodiment, a groove is cut into the substrate to be processed based on the cross-sectional dimensions of the conductive metal substrate, and controlled-depth milling is performed on the substrate to be processed based on the height of the conductive metal substrate, milling into the interior of a preset prepreg until the preset prepreg has only a preset thickness remaining. The preset thickness is 50-100 micrometers.
[0079] Understandably, by milling into the interior of the pre-set prepreg and stopping the milling when the insulating dielectric layer formed by the prepreg has only a pre-set thickness remaining, it is possible to ensure that a certain thickness of insulating dielectric layer remains at the bottom of the controlled depth groove. This not only allows the insulating dielectric layer to be processed to form patterned bumps, but also ensures that the high-frequency material core board is completely undamaged during the milling process, thereby improving the reliability of the high-frequency board.
[0080] In some embodiments, the step of controlling the depth of the material to be processed based on the dimensions of the conductive metal substrate until the bottom of the controlled depth groove is an insulating dielectric layer with a preset thickness further includes: drilling a hole in the material to be processed to obtain at least one hole.
[0081] The number of holes can be set according to actual needs. The number of holes can be one, two or more, and this application does not limit it.
[0082] The hole can be a through hole or a blind hole; this application does not limit this.
[0083] Specifically, please refer to Figure 5 , Figure 5 This is a schematic diagram of one embodiment of the material to be processed obtained in S24.
[0084] In this embodiment, the substrate 100 to be processed includes a high-frequency material core board 20 and multilayer core boards 11 disposed on both sides of the high-frequency material core board 20. The high-frequency material core board 20 includes a first surface 21 and a second surface 22 disposed opposite to each other. The first surface 21 is bonded to the adjacent core board 11 by a pre-set prepreg 30, and the second surface 22 is bonded to the adjacent core board 11 by a prepreg 12. Adjacent core boards 11 are bonded together by a prepreg 12. The thickness of the pre-set prepreg 30 is greater than the thickness of the prepreg 12. The thickness of the pre-set prepreg 30 is 150 micrometers. The height difference between one outer surface 101 of the substrate 100 and the first surface 21 of the high-frequency material core board 20 is equal to the thickness of the conductive metal base 10. The substrate 100 to be processed includes at least one through hole 50.
[0085] Among them, a depth control groove 40 is formed on the outer surface 101 of the material to be processed 100. The bottom of the depth control groove 40 is the interior of the preset semi-cured sheet 30, and the thickness of the insulating dielectric layer 31 formed by the remaining preset semi-cured sheet 30 corresponding to the bottom of the depth control groove 40 is 80 micrometers.
[0086] S25: Laser ablation is performed on the insulating dielectric layer based on the morphology of the patterned grooves to form patterned bumps in the remaining insulating dielectric layer.
[0087] In this embodiment, the morphology of the patterned grooves refers to the distribution of multiple grooves and the cross-sectional dimensions of the multiple grooves.
[0088] In this embodiment, the insulating dielectric layer is ablated based on the distribution of multiple grooves in the patterned grooves and the cross-sectional dimensions of the multiple grooves, removing part of the insulating dielectric layer until the first surface of the high-frequency material core board is exposed, and the remaining insulating dielectric layer is formed into patterned bumps. The first surface of the high-frequency material core board serves as the bottom of the subsequently formed metallized groove.
[0089] The patterned bumps consist of multiple separate bumps, and the distribution of these multiple separate bumps is consistent with the distribution of the multiple grooves in the patterned grooves. The cross-sectional dimensions of the multiple bumps are also consistent with the cross-sectional dimensions of the multiple grooves.
[0090] Understandably, laser ablation of the insulating dielectric layer based on the morphology of the patterned grooves can make the resulting patterned bumps match the patterned grooves.
[0091] In this embodiment, after removing part of the insulating dielectric layer until the first surface of the high-frequency material core board is exposed, a first groove is formed on the basis of the depth control groove. The bottom of the first groove is the first surface of the high-frequency material core board. The depth of the first groove is the sum of the depth of the depth control groove and the preset thickness of the insulating dielectric layer. The depth of the first groove is greater than or equal to the height of the conductive metal base.
[0092] Specifically, please refer to Figure 6 , Figure 6 This is a schematic diagram of one embodiment of the sheet material to be processed obtained in S25.
[0093] In this embodiment, the substrate 100 to be processed includes a high-frequency material core board 20 and multilayer core boards 11 disposed on both sides of the high-frequency material core board 20. The high-frequency material core board 20 includes a first surface 21 and a second surface 22 disposed opposite to each other. The first surface 21 is bonded to the adjacent core board 11 by a pre-set prepreg 30, and the second surface 22 is bonded to the adjacent core board 11 by a prepreg 12. Adjacent core boards 11 are bonded together by a prepreg 12. The thickness of the pre-set prepreg 30 is greater than the thickness of the prepreg 12. The height difference between one outer surface 101 of the substrate 100 to be processed and the first surface 21 of the high-frequency material core board 20 is equal to the thickness of the conductive metal base 10. A first groove 41 is formed on the outer surface 101 of the substrate 100 to be processed. The bottom of the first groove 41 is the first surface 21 of the high-frequency material core board 20. Patterned bumps are formed on the bottom of the first groove 41. The patterned bumps include a plurality of separate bumps 32. The height of the bump 32 is 80 micrometers. The substrate 100 to be processed includes at least one through hole 50.
[0094] S26: After copper plating, the substrate to be processed is electroplated to obtain conductive patterned bumps and metallized grooves to obtain the substrate to be processed; wherein, the depth of the metallized groove is greater than or equal to the height of the conductive metal base.
[0095] In this embodiment, the substrate to be processed is subjected to copper plating to deposit a conductive thin film on the bottom and sidewalls of the first groove and the top and sidewalls of the patterned bumps. Then, the substrate to be processed is electroplated to form a conductive layer on the conductive thin film, thereby obtaining conductive patterned bumps and metallized grooves.
[0096] In some embodiments, a conductive film is formed on the hole wall of the board to be processed by copper plating, and a conductive layer is formed on the corresponding conductive film on the hole wall by electroplating, thereby obtaining a metallized hole.
[0097] Specifically, please refer to Figure 7 , Figure 7 This is a schematic diagram of the structure of the material to be processed obtained in S26 according to one embodiment.
[0098] In this embodiment, the substrate 200 to be processed includes a high-frequency material core board 20 and multilayer core boards 11 disposed on both sides of the high-frequency material core board 20. The high-frequency material core board 20 includes a first surface 21 and a second surface 22 disposed opposite to each other. The first surface 21 is bonded to the adjacent core board 11 by a pre-set prepreg 30, and the second surface 22 is bonded to the adjacent core board 11 by a prepreg 12. Adjacent core boards 11 are bonded together by a prepreg 12. The thickness of the pre-set prepreg 30 is greater than the thickness of the prepreg 12. The height difference between one outer surface 101 of the substrate 200 and the first surface 21 of the high-frequency material core board 20 is equal to the thickness of the conductive metal base 10. The substrate 200 to be processed has a metallized groove 42 formed on its outer surface 101. The bottom of the metallized groove 42 is the first surface 21 of the high-frequency material core board 20. Conductive patterned bumps are formed on the bottom of the metallized groove 42. The conductive patterned bumps include multiple separate bumps 32. A conductive layer 60 is formed on the top and sidewalls of the bumps 32. A conductive layer 60 is also formed on the sidewalls of the metallized groove 42. The height of the bumps 32 is 80 micrometers. The substrate 200 to be processed includes at least one metallized through-hole 51. A conductive layer 60 is formed on the sidewalls of the metallized through-hole 51.
[0099] S27: Place the conductive metal substrate in the metallized groove of the substrate to be treated, and make the patterned groove fit into the conductive patterned bump.
[0100] Specifically, please refer to Figure 8 , Figure 8 This is a schematic diagram of the structure of the material to be processed obtained in S27 according to one embodiment.
[0101] In this embodiment, the substrate 200 to be processed includes a high-frequency material core board 20 and multilayer core boards 11 disposed on both sides of the high-frequency material core board 20. The high-frequency material core board 20 includes a first surface 21 and a second surface 22 disposed opposite to each other. The first surface 21 is bonded to the adjacent core board 11 by a pre-set prepreg 30, and the second surface 22 is bonded to the adjacent core board 11 by a prepreg 12. Adjacent core boards 11 are bonded together by a prepreg 12. The thickness of the pre-set prepreg 30 is greater than the thickness of the prepreg 12. The height difference between one outer surface 101 of the substrate 200 and the first surface 21 of the high-frequency material core board 20 is equal to the thickness of the conductive metal base 10. The metallized groove 42 is formed on the outer surface 101 of the substrate 200 to be processed. The bottom of the metallized groove 42 is the first surface 21 of the high-frequency material core board 20. Conductive patterned bumps are formed on the bottom of the metallized groove 42. The conductive patterned bumps include multiple separate bumps 32. A conductive layer 60 is formed on the top and sidewall of the bumps 32. A conductive layer 60 is formed on the sidewall of the metallized groove 42. The substrate 200 to be processed includes at least one metallized through hole 51. A conductive layer 60 is formed on the sidewall of the metallized through hole 51. A conductive metal base 10 is accommodated in the metallized groove 42. A patterned groove is provided on one side surface of the conductive metal base 10. The patterned groove includes multiple grooves 16 distributed in an array. The multiple grooves 16 are fitted one by one with the multiple separate bumps 32 in the conductive patterned bumps.
[0102] S28: Fill the gap between the conductive metal base and the conductive patterned bumps with conductive adhesive.
[0103] In this embodiment, the conductive adhesive includes at least one of conductive heat dissipation copper paste, conductive resin, and conductive copper powder.
[0104] Understandably, since there may be dimensional deviations between the patterned grooves and the conductive patterned bumps, that is, the gaps formed between the patterned grooves and the conductive patterned bumps, the gaps between the patterned grooves and the conductive patterned bumps can be filled by filling with conductive adhesive, so as to make the fit between the conductive metal substrate and the metallized groove more secure, thereby further improving the embedding stability of the conductive metal substrate.
[0105] S29: Prepare a circuit pattern on one side surface of the board material to be processed, where a conductive metal base is embedded, and form a solder resist layer on the outer surface of the circuit pattern to obtain a circuit board.
[0106] Understandably, by forming a solder resist layer on the outer surface of the side of the board material to be processed where the conductive metal substrate is embedded, the circuit pattern and the conductive metal substrate can be protected by the solder resist layer, thereby improving the reliability and stability of the circuit board.
[0107] Specifically, please refer to Figure 9 , Figure 9 This is a schematic diagram of one embodiment of the circuit board of this application.
[0108] In this embodiment, the circuit board 300 includes a high-frequency material core board 20 and multilayer core boards 11 disposed on both sides of the high-frequency material core board 20. The high-frequency material core board 20 includes a first surface 21 and a second surface 22 disposed opposite to each other. The first surface 21 is bonded to the adjacent core board 11 by a pre-set prepreg 30, and the second surface 22 is bonded to the adjacent core board 11 by a prepreg 12. Adjacent core boards 11 are bonded together by a prepreg 12. The thickness of the pre-set prepreg 30 is greater than the thickness of the prepreg 12. A metallized groove 42 is formed on the outer surface 101 of the circuit board 300. The bottom of the metallized groove 42 is the first surface 21 of the high-frequency material core board 20. Conductive patterned bumps are formed on the bottom of the metallized groove 42. The conductive patterned bumps include multiple separate bumps 32. A conductive layer 60 is formed on the top and sidewall of each bump 32. A conductive layer 60 is also formed on the sidewall of the metallized groove 42. The circuit board 300 includes at least one metallized through-hole 51. The conductive metal base 10 is housed in the metallized groove 42, and the depth of the metallized groove 42 is equal to the height of the conductive metal base 10. A patterned groove is formed on one side surface of the conductive metal base 10. The patterned groove includes a plurality of grooves 16 arranged in an array, and the plurality of grooves 16 are fitted into a plurality of separate bumps 32 in the conductive patterned bumps. The space between the plurality of grooves 16 and the plurality of bumps 32 is filled with conductive adhesive (not shown). A circuit pattern 102 is formed on the outer surface 101 of the circuit board 300, and a solder resist layer 70 is formed on the outer surface of the circuit pattern 102.
[0109] Unlike related technologies, this application obtains a conductive metal substrate with patterned grooves on its surface and a substrate to be processed with metallized grooves on its surface. Conductive patterned bumps are provided at the bottom of the metallized grooves, and the conductive patterned bumps correspond to the patterned grooves. The conductive metal substrate is placed in the metallized grooves of the substrate to be processed, and the patterned grooves and conductive patterned bumps are fitted together. The interlocking effect between the patterned grooves and conductive patterned bumps can improve the bonding force between the conductive metal substrate and the substrate to be processed, thereby reducing the probability of conductive metal substrate displacement, improving the embedding stability of the conductive metal substrate, and thus improving the reliability of the copper embedding process and the product yield.
[0110] The above description is merely an embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.
Claims
1. A method for manufacturing a circuit board, characterized in that, include: A conductive metal substrate with patterned grooves on its surface was obtained; A substrate with metallized grooves on its surface is obtained; wherein, a conductive patterned bump is provided at the bottom of the metallized groove, and the conductive patterned bump corresponds to the patterned groove; the size of the metallized groove is greater than or equal to the size of the conductive metal base; The conductive metal base is placed in the metallized groove of the plate to be treated, and the patterned groove is fitted with the conductive patterned bump.
2. The preparation method according to claim 1, characterized in that, The step of obtaining the plate to be processed with metallized grooves on its surface includes: A material to be processed is obtained; wherein the thickness of the material to be processed is greater than the height of the conductive metal base, and the cross-sectional dimension of the material to be processed is greater than the cross-sectional dimension of the conductive metal base; Based on the dimensions of the conductive metal base, the material to be processed is subjected to controlled-depth milling until the bottom of the controlled-depth groove is an insulating dielectric layer with a preset thickness; wherein, the depth of the controlled-depth groove is less than the height of the conductive metal base, and the sum of the preset thickness of the insulating dielectric layer and the depth of the controlled-depth groove is greater than or equal to the height of the conductive metal base; The insulating dielectric layer is laser-ablated based on the morphology of the patterned grooves to form patterned bumps in the remaining insulating dielectric layer. The substrate to be processed is subjected to copper plating followed by electroplating to obtain the conductive patterned bumps and the metallized grooves, thereby obtaining the substrate to be processed; wherein the depth of the metallized grooves is greater than or equal to the height of the conductive metal base.
3. The preparation method according to claim 2, characterized in that, The step of obtaining the material to be processed includes: A high-frequency material core board is obtained; wherein the high-frequency material core board has a first surface and a second surface disposed opposite to each other; the cross-sectional dimension of the high-frequency material core board is larger than the cross-sectional dimension of the conductive metal substrate; A pre-cured sheet and a single-layer core board are pressed together on the first surface of the high-frequency material core board, and a pre-cured sheet and the single-layer core board are pressed together on the second surface of the high-frequency material core board; wherein, the thickness of the pre-cured sheet is greater than that of the pre-cured sheet. At least on the first surface of the high-frequency material core board, the prepreg and the single-layer core board are pressed together until the height difference between the surface of the outermost core board on the first surface and the first surface is greater than or equal to the height of the conductive metal base. Then, the layering is stopped to obtain the material to be processed.
4. The preparation method according to claim 3, characterized in that, The step of controlling the depth of the plate to be processed based on the dimensions of the conductive metal base until the bottom of the controlled depth groove is an insulating dielectric layer of a certain thickness includes: Grooving is performed on the plate to be processed based on the cross-sectional dimensions of the conductive metal substrate; Based on the height of the conductive metal base, the material to be processed is subjected to controlled-depth milling until it reaches the interior of the preset semi-cured sheet, until the preset semi-cured sheet has only the preset thickness remaining; wherein the preset thickness is 50~100 micrometers.
5. The preparation method according to claim 4, characterized in that, The step of laser ablation of the insulating dielectric layer based on the morphology of the patterned grooves to form patterned bumps in the remaining insulating dielectric layer includes: Based on the distribution of multiple grooves in the patterned grooves and the cross-sectional dimensions of the multiple grooves, the insulating dielectric layer is ablated to remove part of the insulating dielectric layer until the first surface of the high-frequency material core plate is exposed, and the remaining insulating dielectric layer forms the patterned bumps; wherein, the first surface of the high-frequency material core plate is the bottom of the metallized groove.
6. The preparation method according to claim 2, characterized in that, The step of controlling the depth of the plate to be processed based on the dimensions of the conductive metal base until the bottom of the controlled depth groove is an insulating dielectric layer with a preset thickness further includes: Drill holes in the material to be processed to obtain at least one hole; The step of performing copper plating followed by electroplating on the substrate to be processed to obtain the conductive patterned bumps and the metallized grooves, thereby obtaining the substrate to be processed, further includes: After forming a conductive thin film on the hole wall by copper plating, a conductive layer is formed on the conductive thin film by electroplating, thus obtaining a metallized hole.
7. The preparation method according to claim 1, characterized in that, The step of obtaining a conductive metal substrate with patterned grooves on its surface includes: Obtain the metal substrate to be processed; Based on a preset pattern, one side surface of the metal substrate to be processed is subjected to controlled-depth milling to form the patterned groove, thereby obtaining the conductive metal substrate.
8. The preparation method according to claim 1, characterized in that, After the step of placing the conductive metal substrate in the metallized groove of the substrate to be treated and engaging the patterned groove with the conductive patterned bump, the method includes: The gap between the conductive metal base and the conductive patterned bumps is filled with a conductive adhesive.
9. The preparation method according to claim 8, characterized in that, After the step of filling the gap between the conductive metal substrate and the conductive patterned bumps with conductive adhesive, the method includes: A circuit pattern is prepared on one side surface of the substrate to be processed, where the conductive metal base is embedded, and a solder resist layer is formed on the outer surface of the circuit pattern to obtain the circuit board.
10. A circuit board, characterized by The circuit board is manufactured by the circuit board preparation method according to any one of claims 1 to 9; wherein the circuit board includes a metallized groove, and a conductive patterned bump is provided at the bottom of the metallized groove, and the conductive patterned bump is fitted and connected to a conductive metal base with a patterned groove on its surface.