Embedded resistor structure and manufacturing method thereof

Abstract

The invention provides an embedded resistor structure and a manufacturing method thereof, and the manufacturing method comprises the steps: providing a substrate with a thickness direction, and enabling the substrate to be provided with a through hole in a penetrating manner; depositing a resistance material on the side wall of the through hole to form a plurality of resistor discs which are arranged at intervals and are not conducted mutually; filling resin in the through hole to form an insulator; removing part of the resistor material at the two opposite ends of the resistor disc to form a resistor structure; a first circuit layer and a second circuit layer are formed on the two opposite sides of the substrate respectively, the first circuit layer comprises a plurality of first electrodes, the first electrodes are partially embedded into the through holes and connected with one end of the resistor structure, the second circuit layer comprises a plurality of second electrodes, and the second electrodes are partially embedded into the through holes and electrically connected with the other end of the resistor structure. According to the embedded resistor structure, the connection reliability of the resistor structure and the electrode is high, and the resistor has good electrical environment and chemical corrosion resistance.

Description

Technical Field

[0001] The present application relates to the field of circuit board manufacturing, and in particular to an embedded resistor structure and a manufacturing method thereof. Background Art

[0002] The existing technology of embedding resistors in circuit boards mainly forms resistors by making patterns or printing on the surface of the circuit board. This technology occupies a large space on the circuit board surface, which is not conducive to integration and miniaturization. In addition, the electrodes at both ends of the resistor are directly connected horizontally, and the connection reliability is poor. In addition, the resistor material is exposed or only protected by coating solder mask ink, and the electrical environment and chemical corrosion resistance are poor. Summary of the invention

[0003] In view of this, it is necessary to provide an embedded resistor structure and a manufacturing method thereof to reduce the space occupied by the resistor, improve the connection reliability of the electrodes at both ends of the resistor, and increase the protection of the resistor.

[0004] An embodiment of the present application provides a method for manufacturing an embedded resistor structure, comprising the steps of:

[0005] Providing a substrate, wherein the substrate has a thickness direction, and the substrate is provided with a through hole along the thickness direction;

[0006] Depositing a resistor material at least on the sidewall of the through hole to form a plurality of resistor sheets that are spaced apart and not conductive to each other;

[0007] Filling the through hole with resin to form an insulator;

[0008] Along the thickness direction, removing part of the resistor material at two opposite ends of the resistor sheet to expose part of the through hole to form a resistor structure;

[0009] A first circuit layer and a second circuit layer are respectively formed on opposite sides of the substrate, wherein the first circuit layer includes a plurality of first electrodes, wherein the first electrode portions are embedded in the through holes and connected to one end of the resistor structure, and the second circuit layer includes a plurality of second electrodes, wherein the second electrode portions are embedded in the through holes and electrically connected to the other end of the resistor structure, thereby obtaining the embedded resistor structure.

[0010] Optionally, the step of “depositing a resistor material at least on the sidewall of the through hole to form a plurality of resistor sheets that are spaced apart and not conductive to each other” includes:

[0011] Electroplating and depositing a resistance material on the sidewall of the through hole to form a resistance material layer;

[0012] A plurality of spacing holes are formed through the substrate to remove a portion of the resistance material layer to form the resistance sheet, and the spacing holes are connected to the through holes to form a receiving hole;

[0013] The step of “filling the through hole with resin to form an insulator” also includes:

[0014] The insulator is formed by filling the receiving hole with resin.

[0015] Optionally, the substrate has a width direction and a length direction, and the step of “depositing a resistor material at least on the sidewall of the through hole to form a plurality of resistor sheets that are spaced apart and not conductive to each other” comprises:

[0016] Resistive material is deposited on the sidewall of the through hole to form two groups of resistance patterns, the two groups of resistance patterns are arranged opposite to each other along the width direction, each group of resistance patterns includes a plurality of resistance sheets arranged to extend along the length direction at intervals, and the two ends of each resistance sheet are respectively connected to one of the first electrodes and one of the second electrodes to form a resistor.

[0017] Optionally, the step of “removing part of the resistor material at two opposite ends of the resistor sheet along the thickness direction to expose part of the through hole to form a resistor structure” includes:

[0018] Part of the resistor material at two opposite ends of the resistor sheet is etched along the thickness direction to a target depth to form the resistor structure with two ends being concave.

[0019] Optionally, the step of “forming a first circuit layer and a second circuit layer on opposite sides of the substrate respectively” includes:

[0020] The first circuit layer and the second circuit layer are respectively electroplated and patterned on opposite sides of the substrate, and a plurality of resistors are connected through the first circuit layer and the second circuit layer to form a series or parallel structure.

[0021] Optionally, the substrate comprises a base layer and a first metal layer and a second metal layer provided on two opposite surfaces of the base layer;

[0022] The step of “respectively electroplating and patterning the first circuit layer and the second circuit layer on opposite sides of the substrate” includes:

[0023] Electroplating the first metal layer to form a first plating layer, and electroplating the second metal layer to form a second plating layer;

[0024] The first plating layer and the corresponding first metal layer are patterned to form the first circuit layer, and the second plating layer and the corresponding second metal layer are patterned to form the second circuit layer.

[0025] Optionally, the step of “depositing a resistor material at least on the sidewall of the through hole to form a plurality of resistor sheets that are spaced apart and not conductive to each other” includes:

[0026] Depositing a resistive material on the sidewall of the through hole, on at least a portion of the surface of the first metal layer, and on at least a portion of the surface of the second metal layer to form the resistor;

[0027] After the step of "filling the through hole with resin to form an insulator", the method further includes:

[0028] The portions of the resistor and the insulator protruding from the surface of the substrate are removed by grinding.

[0029] The present application also proposes an embedded resistor structure, which has a thickness direction, and includes a second circuit layer, a base layer and a first circuit layer stacked in sequence along the thickness direction, the base layer is provided with a receiving hole along the thickness direction, the hole wall of the receiving hole is provided with a plurality of resistor structures that are spaced apart and not conductive to each other, and the receiving hole is filled with an insulator; the first circuit layer includes a plurality of first electrodes, each of which is partially embedded in the receiving hole and electrically connected to one end of the resistor structure, the second circuit layer includes a plurality of second electrodes, each of which is partially embedded in the receiving hole and electrically connected to the other end of the resistor structure, and each of the first electrode, the resistor structure and the second electrode constitute a resistor.

[0030] Optionally, a plurality of the resistors are connected through the first circuit layer and the second circuit layer to form a series or parallel structure.

[0031] Optionally, the embedded resistor structure has a length direction and a width direction, and the embedded resistor structure includes a first row of resistors and a second row of resistors spaced apart along the width direction, and the first row of resistors and the second row of resistors respectively include a plurality of resistors spaced apart along the length direction.

[0032] Compared with the prior art, the method for manufacturing the embedded resistor structure provided by the present application has at least the following beneficial effects:

[0033] (1) By vertically embedding the resistor into the board, the horizontal board space can be saved, the integration of the circuit board can be improved, and it is conducive to miniaturization and thinning;

[0034] (2) By opening a through hole and depositing a resistor material on the side wall of the through hole, the size of the resistor can be precisely controlled by controlling the thickness and width of the resistor material and the number and arrangement of the resistor sheets.

[0035] (3) By vertically embedding the resistor structure, embedding the first electrode and the second electrode into the board to electrically connect the two ends of the resistor structure, and providing an insulator for protection, the resistor structure is completely non-contacted with the board surface, which has better electrical environment and chemical corrosion resistance. In addition, the connection between the first electrode and the second electrode and the resistor structure is located in the board, firmly protected by the resin material, not easy to separate, and has high connection reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A schematic cross-sectional view of a substrate provided in accordance with an embodiment of the present application.

[0037] Figure 2 for Figure 1 A top view of the buried barrier region of the substrate is shown.

[0038] Figure 3 For Figure 1 The cross-sectional schematic diagram of the substrate after a through hole is opened is shown.

[0039] Figure 4 for Figure 3 A top view of the buried barrier region of the substrate is shown.

[0040] Figure 5 for Figure 3 A side view of the buried blocking region is shown.

[0041] Figure 6 For Figure 3 The cross-sectional schematic diagram shown is after the through hole is provided with the resistance material layer.

[0042] Figure 7 for Figure 6 A top view of the buried barrier region of the substrate is shown.

[0043] Figure 8 for Figure 6 A side view of the buried blocking region is shown.

[0044] Fig. 9 For the general Figure 6 The cross-sectional schematic diagram of the resistor material layer after forming a plurality of resistor sheets arranged at intervals is shown.

[0045] Fig.10 for Fig. 9 A top view of the buried blocking area is shown.

[0046] Fig.11 for Fig. 9 A side view of the buried blocking region is shown.

[0047] Fig.12 For Fig. 9 The schematic cross-sectional view of the receiving hole after being filled with resin to form an insulator is shown.

[0048] Fig.13 for Fig.12 A top view of the buried blocking area is shown.

[0049] Fig.14 for Fig.12 A side view of the buried blocking region is shown.

[0050] Fig.15 For the general Fig.12 The cross-sectional view is shown after the redundant parts of the resistor and the insulator are removed.

[0051] Fig.16 For the general Fig.15 The cross-sectional view of the resistor structure is shown after a portion of the resistor sheet is removed.

[0052] Fig.17 for Fig.16 A side view of the buried blocking region is shown.

[0053] Fig.18 For Fig.16 The schematic cross-sectional view shows surfaces of the first metal layer and the second metal layer after being electroplated to form a first plated layer and a second plated layer, respectively.

[0054] Fig.19 for Fig.18 A side view of the buried blocking region is shown.

[0055] Fig. 20 For the general Fig.18 The cross-sectional schematic diagram is shown after the first plating layer and the second plating layer are patterned to form the first circuit layer and the second circuit layer respectively.

[0056] Fig.21 for Fig. 20 A top view of the buried blocking area is shown.

[0057] Fig. 22 for Fig. 20 A side view of the buried blocking region is shown.

[0058] Fig.23 A cross-sectional schematic diagram of an embedded resistor structure provided in one embodiment of the present application.

[0059] The following specific implementation methods will further illustrate the present application in conjunction with the above-mentioned drawings.

[0060] Main component symbols

[0061] Embedded resistor structure 100

[0062] Substrate 10

[0063] Base 11

[0064] The first metal layer 12

[0065] The second metal layer 13

[0066] Through hole 15

[0067] Side wall 151

[0068] Resistive material layer 20

[0069] Spacing hole 21

[0070] Resistor pattern 22

[0071] Resistor 221

[0072] Receiving hole 25

[0073] Insulator 30

[0074] Resistor structure 40

[0075] First plating layer 42

[0076] Second plating layer 44

[0077] The first circuit layer 50

[0078] First electrode 502

[0079] Second circuit layer 52

[0080] Second electrode 522

[0081] Intermediate 55

[0082] Resistor 60

[0083] First row resistance 70

[0084] Second row resistance 72

[0085] First copper clad laminate 80

[0086] First insulating layer 801

[0087] First copper layer 802

[0088] Second copper clad laminate 82

[0089] The second insulating layer 821

[0090] The second copper layer 822

[0091] Buried resistance area R

[0092] Thickness direction Z

[0093] Length direction Y

[0094] Width direction X DETAILED DESCRIPTION

[0095] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0096] See also Figures 1 to 23 An embodiment of the present application provides a method for manufacturing an embedded resistor structure 100, comprising the following steps:

[0097] Step S1, see Figure 1 and Figure 2 , a substrate 10 is provided, including a base layer 11 and a first metal layer 12 and a second metal layer 13 arranged on opposite sides of the base layer 11.

[0098] The cross section of the substrate 10 is substantially rectangular, and the substrate 10 has a thickness direction Z, a length direction Y, and a width direction X. The second metal layer 13, the base layer 11, and the first metal layer 12 are stacked in sequence along the thickness direction Z. In this embodiment, a buried resistance region R is defined in the substrate 10, i.e., a region to be processed.

[0099] In this embodiment, the material of the base layer 11 can be one of polyimide (PI), polyethylene (PE), Teflon (Teflon), liquid crystal polymer (LCP), polyvinyl chloride polymer (PVC) and the like. In other embodiments, the material of the base layer 11 can also be polyethylene terephthalate (PET), polyethylene naphthalate (PEN) or other resin hard materials. It is understandable that a plurality of circuit layers (not shown) arranged at intervals can also be provided in the base layer 11.

[0100] The first metal layer 12 and the second metal layer 13 may be used as seed layers for subsequent electroplating. In this embodiment, the first metal layer 12 and the second metal layer 13 are copper foils.

[0101] Step S2, see Figure 3 , Figure 4 and Figure 5 At least one through hole 15 is formed through the substrate 10 along the thickness direction Z.

[0102] The through hole 15 may be formed through the buried blocking region R of the substrate 10 by mechanical drilling, laser drilling or the like. The through hole 15 has a side wall 151 corresponding to the base layer 11 .

[0103] In this embodiment, the cross section of the through hole 15 is substantially rectangular. In other embodiments, the through hole 15 may also be in any other shape such as a circle or a polygon.

[0104] It can be understood that the number of the through holes 15 can be determined according to the required resistance value of the embedded resistor.

[0105] Step S3, see Figure 6 , Figure 7 and Figure 8 , a resistance material layer 20 is formed at least on the sidewall 151 of the through hole 15 .

[0106] Specifically, a resistor material is deposited on the sidewall 151 by electroplating to form the resistor material layer 20 , and the size of the resistor can be controlled by controlling the thickness and width of the electroplated resistor material.

[0107] The main components of the resistance material layer 20 are nickel, chromium, tungsten, nickel-phosphorus alloy, titanium-tungsten alloy, etc., and opposite ends of the resistance material layer 20 are electrically connected to the first metal layer 12 and the second metal layer 13 respectively.

[0108] In this embodiment, the resistance material layer 20 is not only formed on the sidewall 151 , but also partially formed on the surface of the first metal layer 12 away from the base layer 11 and the surface of the second metal layer 13 away from the base layer 11 .

[0109] Step S4, see Fig. 9 , Fig.10 and Fig.11 , a portion of the resistance material layer 20 is removed to form a plurality of resistance sheets 221 that are spaced apart and not conductive to each other.

[0110] Specifically, a plurality of spacing holes 21 are formed in the substrate 10 along the thickness direction Z, and the spacing holes 21 are connected with the through hole 15 to form a receiving hole 25, so as to remove part of the resistive material layer 20, thereby dividing the resistive material layer 20 into a plurality of resistor sheets 221 arranged at intervals. In this embodiment, the plurality of spacing holes 21 divide the resistive material layer 20 into two groups of resistor patterns 22 arranged oppositely along the width direction X, and each group of the resistor patterns 22 includes a plurality of resistor sheets 221 arranged at intervals and not connected to each other. The spacing holes 21 can be formed adjacent to the side wall 151 by mechanical drilling, laser drilling, etc. It can be understood that the number and arrangement of the resistor sheets 221 can be flexibly set according to the required resistance size.

[0111] In this embodiment, the number of the spacing holes 21 is four, and each group of resistance patterns 22 includes three electrically isolated resistance sheets 221 .

[0112] It can be understood that the method of providing the spacing holes 21 in this embodiment is only an example. In other embodiments, any other method can be used as long as the resistance material layer 20 can be divided into a plurality of resistance sheets 221 that are spaced apart and not conductive to each other.

[0113] Step S5, see Fig.12 , Fig.13 and Fig.14 , resin is filled into the receiving hole 25 to form an insulator 30 .

[0114] Specifically, a vacuum plugging process may be used to fill epoxy resin, phenolic resin or BT resin (Bismaleimide Triazine) in the receiving hole 25 , and the insulator 30 is formed after being cured.

[0115] See also Fig.15 In some embodiments, step S5 further includes: grinding and removing a portion of the insulator 30 and a portion of the resistor 221 protruding from the surface of the substrate 10 .

[0116] After grinding, one end of the resistor 221 and the insulator 30 is flush with the surface of the first metal layer 12 away from the base layer 11 , and the other end is flush with the surface of the second metal layer 13 away from the base layer 11 .

[0117] Step S6, see Fig.16 and Fig.17 , along the thickness direction Z, remove part of the resistance material at the opposite ends of the resistance sheet 221 to form a resistance structure 40.

[0118] Specifically, an etching method may be adopted to control the etching amount to reach a target depth, thereby forming a concave resistor structure 40 and exposing a portion of the receiving hole 25 .

[0119] Step S7, see Fig.18 and Fig.19 A first plating layer 42 is formed by electroplating on the surface of the first metal layer 12, and a portion of the first plating layer 42 is filled into the receiving hole 25 to connect one end of the resistor structure 40. A second plating layer 44 is formed by electroplating on the surface of the second metal layer 13, and a portion of the second plating layer 44 is filled into the receiving hole 25 to connect the other end of the resistor structure 40.

[0120] The first plating layer 42 and the second plating layer 44 further cover the insulator 30 .

[0121] Step S8, see Fig. 20 , Fig.21 and Fig. 22 , patterning the first plating layer 42 and the corresponding first metal layer 12 to form a first circuit layer 50 , and patterning the second plating layer 44 and the corresponding second metal layer 13 to form a second circuit layer 52 , to obtain an intermediate 55 .

[0122] The first circuit layer 50 includes a plurality of first electrodes 502, each of which is partially embedded in the base layer 11 to electrically connect one end of the resistor structure 40. The second circuit layer 52 includes a plurality of second electrodes 522, each of which is partially embedded in the base layer 11 to electrically connect the other end of the resistor structure 40.

[0123] Each of the first electrodes 502, the resistor structure 40 and the second electrode 522 forms a vertical resistor 60. In this embodiment, the number of the resistors 60 is six, of which three resistors 60 are arranged along the length direction Y to form a first row of resistors 70, and the other three resistors 60 are arranged along the length direction Y to form a second row of resistors 72, and the first row of resistors 70 and the second row of resistors 72 are arranged oppositely and spaced along the width direction X. Multiple resistors 60 can be connected through the first circuit layer 50 and the second circuit layer 52 to form a series or parallel structure.

[0124] In the present application, by opening a through hole 15 and removing part of the resistive material layer 20, a plurality of spaced resistor sheets 221 are vertically formed on the hole wall, and the concave resistor structure 40 is formed by etching, and then the first and second electrodes 502 and 522 are formed horizontally at both ends of the resistor structure 40 by plane electroplating, thereby forming a vertical resistor 60. Among them, the resistor structure 40 is embedded in the base layer 11, and is filled and protected by the insulator 30, and has no contact with the surface, so as to have a good electrical environment and chemical corrosion resistance. In addition, by forming a concave resistor structure 40, the first electrode 502 and the second electrode 522 are embedded and electrically connected to the resistor structure 40, so that the connection between the resistor structure 40 and the first electrode 502 and the second electrode 522 is in the board, and is firmly protected by the resin material (i.e., the insulator 30). Compared with the surface connection method in the prior art, the board connection method in the present application is not easy to separate, which effectively improves the connection reliability, while reducing the contact between the resistor material and the surface and increasing the protection. In addition, the resistor 60 vertically embedded in the board can reduce the horizontal size of the circuit board, and series-parallel resistors can be designed according to needs. Compared with the series-parallel resistors on the existing board, the board area is smaller, and the thickness of the circuit board does not need to be increased due to the margin of the board thickness.

[0125] Step S9, see Fig.23 , adding layers on opposite sides of the intermediate body 55 to obtain an embedded resistor structure 100.

[0126] Specifically, a first copper clad plate 80 and a second copper clad plate 82 are respectively pressed on opposite sides of the intermediate body 55, wherein the first copper clad plate 80 includes a first insulating layer 801 and a first copper layer 802, wherein the first insulating layer 801 covers the first circuit layer 50 and the insulator 30. The second copper clad plate 82 includes a second insulating layer 821 and a second copper layer 822, wherein the second insulating layer 821 covers the second circuit layer 52 and the insulator 30.

[0127] It can be understood that in other embodiments, the embedded resistor structure 100 can be multiplied as needed.

[0128] See also Fig.21 , Fig. 22 and Fig.23One embodiment of the present application also provides an embedded resistor structure 100 manufactured by the above manufacturing method, wherein the embedded resistor structure 100 includes a base layer 11 and a first circuit layer 50 and a second circuit layer 52 arranged on opposite sides of the base layer 11, wherein the base layer 11 is penetrated by a receiving hole 25, and a plurality of resistor structures 40 arranged at intervals and not conducting to each other are arranged on the hole wall of the receiving hole 25, and an insulator 30 is arranged in the receiving hole 25. The first circuit layer 50 includes a plurality of first electrodes 502, which are partially embedded in the receiving hole 25, and each of the first electrodes 502 is electrically connected to one end of the resistor structure 40. The second circuit layer 52 includes a plurality of second electrodes 522, which are partially embedded in the receiving hole 25, and each of the second electrodes 522 is electrically connected to the other end of the resistor structure 40. Each of the first electrodes 502, the resistor structure 40 and the second electrode 522 constitute a vertical resistor 60.

[0129] The embedded resistor structure 100 has a thickness direction Z, a length direction Y and a width direction X, and the receiving hole 25 penetrates the base layer 11 along the thickness direction Z. The hole wall of the receiving hole 25 is provided with a first row of resistors 70 and a second row of resistors 72 which are arranged oppositely along the width direction X. The first row of resistors 70 and the second row of resistors 72 both include a plurality of resistors 60 which are arranged to extend at intervals along the length direction Y. The plurality of resistors 60 can be connected through the first circuit layer 50 and the second circuit layer 52 to form a series or parallel structure.

[0130] In some embodiments, the embedded resistor structure 100 further includes a first copper clad laminate 80 and a second copper clad laminate 82, wherein the first copper clad laminate 80 includes a first insulating layer 801 and a first copper layer 802, wherein the first insulating layer 801 covers the first circuit layer 50 and the insulator 30. The second copper clad laminate 82 includes a second insulating layer 821 and a second copper layer 822, wherein the second insulating layer 821 covers the second circuit layer 52 and the insulator 30.

[0131] Those skilled in the art should recognize that the above implementation modes are only used to illustrate the present application and are not used as limitations on the present application. As long as they are within the essential spirit of the present application, appropriate changes and modifications made to the above embodiments should fall within the scope of protection claimed in the present application.

Claims

1. A method for manufacturing an embedded resistor structure, characterized in that: Includes steps: Providing a substrate, wherein the substrate has a thickness direction, and the substrate is provided with a through hole along the thickness direction; Depositing a resistor material at least on the sidewall of the through hole to form a plurality of resistor sheets that are spaced apart and not conductive to each other; Filling the through hole with resin to form an insulator; Along the thickness direction, removing part of the resistor material at two opposite ends of the resistor sheet to expose part of the through hole to form a resistor structure; A first circuit layer and a second circuit layer are respectively formed on opposite sides of the substrate, wherein the first circuit layer includes a plurality of first electrodes, wherein the first electrode portions are embedded in the through holes and connected to one end of the resistor structure, and the second circuit layer includes a plurality of second electrodes, wherein the second electrode portions are embedded in the through holes and electrically connected to the other end of the resistor structure, thereby obtaining the embedded resistor structure.

2. The method according to claim 1, characterized in that: The step of "depositing a resistor material at least on the sidewall of the through hole to form a plurality of resistor sheets that are spaced apart and not connected to each other" includes: Electroplating and depositing a resistance material on the sidewall of the through hole to form a resistance material layer; A plurality of spacing holes are formed through the substrate to remove a portion of the resistance material layer to form the resistance sheet, and the spacing holes are connected to the through holes to form a receiving hole; The step of "filling the through hole with resin to form an insulator" also includes: The insulator is formed by filling the receiving hole with resin.

3. The method according to claim 1, characterized in that: The substrate has a width direction and a length direction, and the step of "depositing a resistor material at least on the sidewall of the through hole to form a plurality of resistor sheets that are spaced apart and not connected to each other" includes: Resistive material is deposited on the sidewall of the through hole to form two groups of resistance patterns, the two groups of resistance patterns are arranged opposite to each other along the width direction, each group of resistance patterns includes a plurality of resistance sheets arranged to extend along the length direction at intervals, and the two ends of each resistance sheet are respectively connected to one of the first electrodes and one of the second electrodes to form a resistor.

4. The method according to claim 3, characterized in that: The step of "removing part of the resistor material at two opposite ends of the resistor sheet along the thickness direction to expose part of the through hole to form a resistor structure" includes: Part of the resistor material at two opposite ends of the resistor sheet is etched along the thickness direction to a target depth to form the resistor structure with two ends being concave.

5. The method according to claim 4, characterized in that: The step of "forming a first circuit layer and a second circuit layer on opposite sides of the substrate respectively" includes: The first circuit layer and the second circuit layer are respectively electroplated and patterned on opposite sides of the substrate, and a plurality of resistors are connected through the first circuit layer and the second circuit layer to form a series or parallel structure.

6. The method according to claim 5, characterized in that: The substrate comprises a base layer and a first metal layer and a second metal layer disposed on two opposite surfaces of the base layer; The step of "respectively electroplating and patterning the first circuit layer and the second circuit layer on opposite sides of the substrate" includes: Electroplating the first metal layer to form a first plating layer, and electroplating the second metal layer to form a second plating layer; The first plating layer and the corresponding first metal layer are patterned to form the first circuit layer, and the second plating layer and the corresponding second metal layer are patterned to form the second circuit layer.

7. The method according to claim 6, characterized in that: The step of "depositing a resistor material at least on the sidewall of the through hole to form a plurality of resistor sheets that are spaced apart and not connected to each other" includes: Depositing a resistive material on the sidewall of the through hole, on at least a portion of the surface of the first metal layer, and on at least a portion of the surface of the second metal layer to form the resistor; After the step of "filling the through hole with resin to form an insulator", the method further includes: The portions of the resistor and the insulator protruding from the surface of the substrate are removed by grinding.

8. An embedded resistor structure, characterized in that: The embedded resistor structure has a thickness direction, and the embedded resistor structure includes a second circuit layer, a base layer and a first circuit layer stacked in sequence along the thickness direction, the base layer is provided with a receiving hole along the thickness direction, the hole wall of the receiving hole is provided with a plurality of resistor structures that are spaced apart and not conductive to each other, and the receiving hole is filled with an insulator; the first circuit layer includes a plurality of first electrodes, each of which is partially embedded in the receiving hole and electrically connected to one end of the resistor structure, the second circuit layer includes a plurality of second electrodes, each of which is partially embedded in the receiving hole and electrically connected to the other end of the resistor structure, and each of the first electrode, the resistor structure and the second electrode constitute a resistor.

9. The embedded resistor structure according to claim 8, characterized in that: A plurality of resistors are connected through the first circuit layer and the second circuit layer to form a series or parallel structure.

10. The embedded resistor structure according to claim 8, characterized in that: The embedded resistor structure has a length direction and a width direction, and includes a first row of resistors and a second row of resistors spaced apart along the width direction, and the first row of resistors and the second row of resistors respectively include a plurality of resistors spaced apart along the length direction.

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