CN117812821A

CN117812821A - Circuit board and manufacturing method thereof

Info

Publication number: CN117812821A
Application number: CN202211175052.3A
Authority: CN
Inventors: 陈伯元
Original assignee: Avary Holding Shenzhen Co Ltd; Qing Ding Precision Electronics Huaian Co Ltd
Current assignee: Avary Holding Shenzhen Co Ltd; Qing Ding Precision Electronics Huaian Co Ltd
Priority date: 2022-09-26
Filing date: 2022-09-26
Publication date: 2024-04-02

Abstract

The invention provides a circuit board and a manufacturing method thereof. The method comprises filling a first silicon rubber material in a first shielding layer, and coating a first conductive blind hole connected with a first circuit layer; and filling a second silicon rubber material in the second shielding layer, and cladding the second conductive blind holes connected with the second circuit layer, wherein the first shielding layer and the second shielding layer respectively comprise a low-frequency shielding layer and a high-frequency shielding layer. Because the silicone rubber material can be used as a shielding material for electromagnetic radiation, the circuit board of the invention can effectively shield electromagnetic radiation in the signal-derived path.

Description

Circuit board and manufacturing method thereof

Technical Field

The present invention relates to a circuit board and a method for manufacturing the same, and more particularly, to a circuit board with electromagnetic shielding effect and a method for manufacturing the same.

Background

The signals generated by the electronic device comprise a high-frequency signal and a low-frequency signal, and both signals generate electromagnetic waves. Electromagnetic waves generated by each electronic device may interfere with each other, so-called electromagnetic interference (electromagnetic interference, EMI). Furthermore, with miniaturization of electronic equipment products, interference of radiation electromagnetic fields generated by the electronic equipment products is more serious. Therefore, in order to reduce the problem of electromagnetic interference, the electromagnetic shielding effect of the electronic component needs to be improved.

Disclosure of Invention

In one aspect, the present invention provides a method for manufacturing a circuit board, which includes disposing a plurality of silicone rubber materials on a circuit layer to shield electromagnetic radiation generated by signals.

Another aspect of the present invention is to provide a circuit board, which is manufactured by the method of the above aspect.

According to one aspect of the present invention, a method for manufacturing a circuit board is provided, which includes forming a recess in an insulating substrate; placing an electronic element in the groove, wherein the electronic element comprises a first circuit layer; forming a first shielding layer on the insulating substrate and the electronic element, wherein the first shielding layer comprises a first low-frequency shielding layer and a first high-frequency shielding layer; forming a plurality of first openings in the first shielding layer to expose the first circuit layer; filling a plurality of first silicone rubber materials in the plurality of first openings; forming a plurality of first conductive blind holes in the plurality of first silicon rubber materials, wherein the plurality of first conductive blind holes are electrically connected with the first circuit layer; forming a composite layer on the first shielding layer and the plurality of first silicon rubber materials, wherein the composite layer comprises a graphene layer and a metal layer; patterning the composite layer to form a second circuit layer; forming a second shielding layer on the second circuit layer, wherein the second shielding layer comprises a second low-frequency shielding layer and a second high-frequency shielding layer; forming a plurality of second openings on the second shielding layer to expose the second circuit layer; filling a plurality of second silicone rubber materials in the plurality of second openings; and forming a plurality of second conductive blind vias in the plurality of second silicone rubber materials.

According to an embodiment of the present invention, before forming the second shielding layer, the method further includes forming a plurality of conductive vias in the second circuit layer, wherein the plurality of conductive vias are electrically connected to the plurality of first conductive blind vias, respectively.

According to an embodiment of the present invention, the step of forming the composite layer includes forming an insulating layer over the first shielding layer and the plurality of first silicone rubber materials; forming the graphene layer on the insulating layer; and forming the metal layer on the graphene layer.

According to an embodiment of the present invention, the method further includes forming at least one third opening on the second shielding layer and between the plurality of second openings to expose the insulating layer; and filling a third silicone rubber material in the at least one third opening.

According to an embodiment of the present invention, the step of patterning the composite layer includes removing the metal layer; and patterning the graphene layer with a plasma.

According to an embodiment of the present invention, before the electronic component is placed in the recess, the method further includes forming an adhesive layer at a bottom of the recess; and placing the electronic component on the bonding layer.

According to an embodiment of the present invention, the step of forming the first shielding layer includes forming a first dielectric layer on the insulating substrate and the electronic component; forming the first low-frequency shielding layer on the first dielectric layer; and forming the first high-frequency shielding layer on the first low-frequency shielding layer.

According to an embodiment of the present invention, the step of forming the second shielding layer forms a second dielectric layer on the second circuit layer; forming the second low-frequency shielding layer on the second dielectric layer; forming the second high-frequency shielding layer on the second low-frequency shielding layer; and forming a third dielectric layer on the second high-frequency shielding layer.

According to another aspect of the present invention, there is provided a circuit board including an insulating substrate having a recess, an electronic component disposed in the recess, a first wiring layer disposed on a top surface of the electronic component, a first shielding layer disposed on the insulating substrate and the electronic component, a plurality of first silicone rubber materials disposed in the first shielding layer, a second wiring layer disposed on the first shielding layer, a second shielding layer disposed on the second wiring layer, a plurality of second silicone rubber materials disposed in the second shielding layer, and a plurality of second conductive blind holes disposed in the plurality of second conductive blind holes. The first shielding layer overlaps the electronic component. The first conductive blind hole is electrically connected with the first circuit layer, and the second conductive blind hole is electrically connected with the second circuit layer.

According to an embodiment of the present invention, the first shielding layer includes a first dielectric layer disposed on the insulating substrate and the electronic component, a first low-frequency shielding layer disposed on the first dielectric layer, and a first high-frequency shielding layer disposed on the first low-frequency shielding layer.

According to an embodiment of the present invention, the second shielding layer includes a second dielectric layer disposed on the second wiring layer, a second high-frequency shielding layer disposed on the second low-frequency shielding layer, and a third dielectric layer disposed on the second high-frequency shielding layer.

According to an embodiment of the present invention, the circuit board further includes a plurality of conductive vias disposed in the second circuit layer. The plurality of conductive holes are respectively and electrically connected with the plurality of first conductive blind holes.

According to an embodiment of the present invention, the second circuit layer includes at least one of graphene and copper.

According to an embodiment of the present invention, the circuit board further includes a third silicone rubber material disposed in the second shielding layer and between the plurality of second silicone rubber materials.

The circuit board and the manufacturing method thereof utilize the silicon rubber material as the shielding material of electromagnetic radiation and combine the low-frequency shielding layer and the high-frequency shielding layer to shield the electromagnetic radiation in the signal guiding-out route more effectively.

Drawings

The aspects of the invention are best understood from the following detailed description when read with the accompanying drawing figures. It should be noted that as is standard in the industry, many features are not drawn to scale. In fact, the dimensions of many of the features may be arbitrarily scaled for clarity of discussion.

Fig. 1A-1M are cross-sectional views illustrating intermediate stages in the fabrication of a circuit board according to some embodiments of the invention.

Fig. 2A to 2C are cross-sectional views illustrating intermediate stages in the manufacturing process of a circuit board according to other embodiments of the present invention.

Fig. 3A to 3C are cross-sectional views illustrating intermediate stages in the manufacturing process of a circuit board according to other embodiments of the present invention.

Detailed Description

The invention is capable of many different embodiments or examples for implementing different features of the invention. Specific examples of components and arrangements are described below to simplify the present disclosure. These are of course merely examples and are not intended to be limiting. For example, descriptions of first features being formed on or over second features include embodiments where the first and second features are in direct contact, and also include embodiments where other features are formed between the first and second features such that the first and second features are not in direct contact. In addition, the present invention repeats the reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed.

Further, spatially relative terms, such as "below (beacon)", "below (below)", "below (lower)", "above (above)", "above (upper)", and the like, may be used for ease of description of the relationship of the parts or features and other parts or features depicted in the drawings. Spatially relative terms may be intended to encompass different orientations of the element in use or operation in addition to the orientation depicted in the figures. The device may be otherwise oriented (rotated 90 degrees or in other directions), and the spatially relative descriptions used in the present invention may be interpreted as such.

As used herein, "about", "near" or "substantially" generally means within 20 percent, or within 10 percent, or within 5 percent of the stated value or range.

The existing common method for shielding electromagnetic radiation is to seal the outside of the circuit board by using shielding conductive materials, and most of the shielding conductive materials are metal, but the shielding conductive materials have the defects of high price and difficult processing and forming. Therefore, the present invention provides a circuit board and a method of manufacturing the same, which uses a silicone rubber material as a shielding material for electromagnetic radiation, and combines a low frequency shielding layer and a high frequency shielding layer to more effectively shield electromagnetic radiation in a signal-guiding path.

Fig. 1A-1M illustrate cross-sectional views of intermediate stages in the fabrication of a circuit board 100 according to some embodiments of the invention. First, referring to fig. 1A, an insulating substrate 110 is provided, and a recess R1 is formed in the insulating substrate 110. Next, referring to fig. 1B, the electronic component 120 is placed in the recess R1, and the first circuit layer 125 is formed on the electronic component 120. In some embodiments, an adhesive layer 115 is formed on the bottom of the recess R1, and the electronic component 120 is placed on the adhesive layer 115.

Referring to fig. 1C, a first shielding layer 130 is formed on the insulating substrate 110 and the electronic device 120. In other words, the first shielding layer 130 overlaps the electronic component 120. In some embodiments, the first shield layer 130 includes a first dielectric layer 135, a first low frequency shield layer 140, and a first high frequency shield layer 145. Therefore, the step of forming the first shielding layer 130 includes forming the first dielectric layer 135 on the insulating substrate 110 and the electronic component 120, forming the first low frequency shielding layer 140 on the first dielectric layer 135, and then forming the first high frequency shielding layer 145 on the first low frequency shielding layer 140. It should be noted that the first dielectric layer 135 is also partially formed in the recess R1 (refer to fig. 1B) and on the adhesive layer 115.

In some embodiments, the first dielectric layer 135 includes an insulating line and a shielding layer to protect the first line layer 125. In some embodiments, the first low frequency shielding layer 140 comprises a carbon fiber composite material to shield electromagnetic radiation in the low frequency range. In some embodiments, the first high frequency shielding layer 145 comprises an alloy mesh, which may be nickel, chromium, copper, silver, gold, and any combination of the foregoing metallic materials, to shield electromagnetic radiation in the high frequency range. In some embodiments, the first high frequency shielding layer 145 may be formed using electroless plating, physical vapor deposition (physical vapor deposition, PVD) (e.g., evaporation or sputtering), chemical vapor deposition (chemical vapor deposition, CVD), or electroplating.

Referring to fig. 1D, a first opening O1 is formed in the first shielding layer 130. In some embodiments, the first opening O1 passes through the first high frequency shielding layer 145 and the first dielectric layer 135 to expose the first circuit layer 125. Next, referring to fig. 1E, the first silicone rubber material 150 is filled in the first opening O1 (refer to fig. 1D). In some embodiments, the bottom of the first silicone rubber material 150 contacts the first wiring layer 125, and the top of the first silicone rubber material 150 is flush with the top surface 145T of the first high frequency shielding layer 145. The first silicone rubber material 150 is mainly used for shielding electromagnetic waves, and compared with the existing shielding conductive material (i.e. metal), the silicone rubber composite material contained in the first silicone rubber material 150 can not only effectively inhibit electromagnetic radiation, but also prevent interference of external electromagnetic radiation on the circuit board, and can also reduce material cost.

Referring to fig. 1F, a hole is drilled in the first silicone rubber material 150 to form an opening (not shown). It should be noted that the width of the opening is smaller than the first opening O1. Then, the openings are filled with a conductive material to form first conductive blind holes 155 in the first silicone rubber material 150 and electrically connected to the first circuit layer 125. In some embodiments, the first conductive blind via 155 may be formed using electroplating and electroless plating methods to fill with a conductive material. In one embodiment, the first conductive blind via 155 comprises copper.

Referring to fig. 1G, a composite layer 165 is formed on the first shielding layer 130 and the first silicone rubber material 150. In some embodiments, the composite layer 165 includes an insulating layer 160, a graphene layer 161, and a metal layer 163. Thus, the step of forming the composite layer 165 includes forming the insulating layer 160 on the first shielding layer 130 and the first silicone rubber material 150, forming the graphene layer 161 on the insulating layer 160, and then forming the metal layer 163 on the graphene layer 161. In one embodiment, metal layer 163 comprises copper.

Fig. 1H to 1M illustrate an example of manufacturing a circuit board 100 having a low frequency signal line. Referring to fig. 1H, the composite layer 165 (see fig. 1G) is patterned to form a second circuit layer 170. First, the metal layer 163 (see fig. 1G) is exposed and developed to form a metal wiring layer 168 on the graphene layer 161 (see fig. 1G). Next, the graphene layer 161 is etched using oxygen plasma to form a graphene wiring layer 166 on the insulating layer 160. In some embodiments, as shown in fig. 1H, the second wire layer 170 includes a metal wire layer 168 and a graphene wire layer 166.

Referring to fig. 1I, the second circuit layer 170 and the insulating layer 160 may be drilled to form an opening (not shown) extending from the second circuit layer 170 to the insulating layer 160, wherein the opening may partially expose one end of the first conductive via 155. Next, a conductive material is filled into the opening to form a conductive via 175 through the second circuit layer 170 and the insulating layer 160, and electrically connected to the first conductive via 155. In some embodiments, the conductive holes 175 may be formed by filling conductive material using electroplating and electroless plating methods. In one embodiment, the conductive via 175 comprises copper.

Referring to fig. 1J, a second shielding layer 180 is formed on the second circuit layer 170. In some embodiments, the second shield layer 180 includes a second dielectric layer 182, a second low frequency shield layer 184, a second high frequency shield layer 186, and a third dielectric layer 188. Therefore, the step of forming the second shielding layer 180 includes forming the second dielectric layer 182 on the second circuit layer 170 and the insulating layer 160, forming the second low frequency shielding layer 184 on the second dielectric layer 182, forming the second high frequency shielding layer 186 on the second low frequency shielding layer 184, and forming the third dielectric layer 188 on the second high frequency shielding layer 186.

In some embodiments, the second dielectric layer 182 includes an insulating line and a shielding layer to protect the first line layer 125. In some embodiments, the second low frequency shielding layer 184 comprises a carbon fiber composite material to shield electromagnetic radiation in the low frequency range. In some embodiments, the second high frequency shielding layer 186 comprises an alloy mesh, which may be nickel, chromium, copper, silver, gold, and any combination of the foregoing metallic materials, to shield electromagnetic radiation in the high frequency range. In some embodiments, the second high frequency shield layer 186 may be formed using electroless plating, physical vapor deposition (physical vapor deposition, PVD) (e.g., evaporation or sputtering), chemical vapor deposition (chemical vapor deposition, CVD), or electroplating. The third dielectric layer 188 is used to protect the second high frequency shielding layer 186 and the second low frequency shielding layer 184.

Referring to fig. 1K, a second opening O2 is formed in the second shielding layer 180 to expose the metal wiring layer 168 of the second wiring layer 170. In some embodiments, the second opening O2 extends from the third dielectric layer 188 into a portion of the second dielectric layer 182. In some embodiments, the third opening O3 may be selectively formed to expose the insulating layer 160. In some embodiments, the third opening O3 is between at least two second openings O2. In some embodiments, the third opening O3 extends from the third dielectric layer 188 to the top of the insulating layer 160 and exposes the sidewalls of the second wiring layer 170. Therefore, the depth of the third opening O3 is greater than the depth of the second opening O2.

Referring to fig. 1L, a second silicone rubber material 190 is filled in the second opening O2 (see fig. 1K). In some embodiments, the bottom of the second silicon rubber material 190 contacts the second wiring layer 170 (or the metal wiring layer 168), and the top of the second silicon rubber material 190 is flush with the top surface 188T of the third dielectric layer 188. In some embodiments of forming the third opening O3 described above (referring to fig. 1K), the third silicone rubber material 192 may be filled within the third opening O3. In this embodiment, the bottom of the third silicon rubber material 192 contacts the insulating layer 160 and the top of the third silicon rubber material 192 is flush with the top surface 188T of the third dielectric layer 188. In some embodiments, the first silicone rubber material 150, the second silicone rubber material 190, and the third silicone rubber material 192 comprise the same silicone rubber composite. Therefore, the second silicone rubber material 190 and the third silicone rubber material 192 are also used for shielding electromagnetic waves.

Referring to fig. 1M, a second conductive via 195 is formed in the second silicone rubber material 190 to electrically connect the second wiring layer 170 (or the metal wiring layer 168). In some embodiments, a pad 195A may be formed on top of the second conductive blind via 195. In some embodiments, forming the second conductive blind via 195 includes forming an opening (not shown) in the second silicone rubber material 190 and then filling (e.g., electroplating) the conductive material into the opening. Note that no conductive blind via is formed in the third silicone rubber material 192. As shown in fig. 1M, the circuit board 100 manufactured according to the above steps mainly uses the metal wiring layer 168 to transmit low-frequency signals.

Referring to fig. 2A-2C, cross-sectional views of intermediate stages of a manufacturing process of a circuit board 200 according to some embodiments of the invention are shown. Fig. 2A to 2C illustrate a circuit board 200 having high frequency signal lines. The following manufacturing process of the circuit board 200 may be explained beginning with the structure of fig. 1G. Referring to fig. 2A, the entire metal layer 163 is removed. In other words, the composite layer 165 in fig. 1G may not include the metal layer 163, and the step of removing the metal layer 163 may be omitted. Accordingly, the structure shown in fig. 2A includes an insulating substrate 110, an electronic component 120 on the insulating substrate 110, a first wiring layer 125 on the electronic component 120, a first shielding layer 130 on the insulating substrate 110 and the electronic component 120, a first silicone rubber material 150 in the first shielding layer 130, a first conductive blind via 155 in the first silicone rubber material 150, an insulating layer 160 on the first shielding layer 130, and a graphene layer 161 on the insulating layer 160.

Referring to fig. 2B, the graphene layer 161 (refer to fig. 2A) is patterned to form a second circuit layer 270. In some embodiments, the graphene layer 161 is etched using an oxygen plasma to form a second line layer (or graphene line layer) 270 on the insulating layer 160.

Next, referring to fig. 2C, similar steps to those of fig. 1I to 1L are performed on the structure of fig. 2B, in which a conductive hole 175 is formed through the second circuit layer 270 and the insulating layer 160; forming a second shielding layer 180 on the second line layer 270; a second silicone rubber material 190 and a third silicone rubber material 192 are formed. Then, a second conductive blind via 195 is formed in the second silicone rubber material 190 to electrically connect the second wiring layer (or the graphene wiring layer) 270, thereby manufacturing the circuit board 200 as shown in fig. 2C. The circuit board 200 manufactured according to the above steps mainly uses the graphene circuit layer (i.e., the second circuit layer 270) to transmit the high-frequency signal.

Referring to fig. 3A-3C, cross-sectional views of intermediate stages of a manufacturing process of a circuit board 300 according to some embodiments of the invention are shown. Fig. 3A to 3C illustrate a circuit board 300 having a high frequency signal line and a low frequency signal line. The following manufacturing process of the circuit board 300 may be explained beginning with the structure of fig. 1G. Referring to fig. 3A, an exposure and development process is performed to pattern the metal layer 163 (see fig. 1G) to form a metal circuit layer 368. It should be noted that the pattern of the metal wiring layer 368 is different from that of the metal wiring layer 168, and the metal wiring layer 368 is only above a portion of the first wiring layer 125 and not above other portions of the first wiring layer 125.

The structure shown in fig. 3A includes an insulating substrate 110, an electronic component 120 on the insulating substrate 110, a first wiring layer 125 on the electronic component 120, a first shielding layer 130 on the insulating substrate 110 and the electronic component 120, a first silicone rubber material 150 in the first shielding layer 130, a first conductive blind via 155 in the first silicone rubber material 150, an insulating layer 160 on the first shielding layer 130, a graphene layer 161 on the insulating layer 160, and a metal wiring layer 368 on the graphene layer 161.

Referring to fig. 3B, the graphene layer 161 (see fig. 3A) is patterned to form a graphene line layer 366. In some embodiments, the graphene layer 161 is etched using an oxygen plasma to form a graphene line layer 366. In some embodiments, as shown in fig. 3B, the second wire layer 370 includes a metal wire layer 368 and a graphene wire layer 366. In contrast to the graphene line layer 166 of the second line layer 170 being completely covered by the metal line layer 168, a portion of the graphene line layer 366 of the second line layer 370 shown in fig. 3B is not covered by the metal line layer 368.

Next, referring to fig. 3C, similar steps to those of fig. 1I to 1L are performed on the structure of fig. 3B, in which a conductive hole 175 is formed through the second circuit layer 370 and the insulating layer 160; forming a second shielding layer 180 on the second line layer 370; a second silicone rubber material 190 and a third silicone rubber material 192 are formed. Then, a second conductive blind via 195 is formed in the second silicone rubber material 190 to electrically connect the second circuit layer 370, thereby obtaining the circuit board 300 shown in fig. 3C. The circuit board 300 manufactured according to the above steps can mainly utilize the graphene circuit layer 366 to transmit high-frequency signals and the metal circuit layer 368 to transmit low-frequency signals.

As described above, the present invention provides a circuit board and a method for manufacturing the same, which uses a silicone rubber material as a shielding material for electromagnetic radiation, and the silicone rubber material is disposed around a conductive blind hole, and combines a low frequency shielding layer and a high frequency shielding layer to shield electromagnetic radiation generated by signals of each circuit.

While the present invention has been described with reference to several embodiments, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention, and it is intended that the invention be limited only by the terms of the appended claims.

[ symbolic description ]

100 circuit board

110 insulating substrate

115 adhesive layer

120 electronic component

125 first line layer

130 first shielding layer

135 first dielectric layer

140 first low frequency shielding layer

145 first high-frequency shielding layer

145T top surface

150 first Silicone rubber Material

155 first conductive blind via

160 insulating layer

161 graphene layer

163 Metal layer

165 composite layer

166 graphene circuit layer

168 metal wiring layer

170 second circuit layer

175 conductive holes

180 second shielding layer

182 second dielectric layer

184 second Low frequency Shielding layer

186 second high frequency shielding layer

188 third dielectric layer

188T top surface

190 second Silicone rubber Material

192 third Silicone rubber Material

195 second conductive blind via

195A liner

200 circuit board

270 second circuit layer

300 circuit board

366 graphene circuit layer

368 Metal Circuit layer

370 second circuit layer

O1 first opening

O2-second opening

O3 third opening

R1 is a groove.

Claims

1. A method of manufacturing a circuit board, comprising:

forming a groove in the insulating substrate;

placing an electronic element in the groove, wherein the electronic element comprises a first circuit layer;

forming a first shielding layer on the insulating substrate and the electronic element, wherein the first shielding layer comprises a first low-frequency shielding layer and a first high-frequency shielding layer;

forming a plurality of first openings in the first shielding layer to expose the first circuit layer;

filling a plurality of first silicone rubber materials in the plurality of first openings;

forming a plurality of first conductive blind holes in the plurality of first silicon rubber materials, wherein the plurality of first conductive blind holes are electrically connected with the first circuit layer;

forming a composite layer on the first shielding layer and the plurality of first silicon rubber materials, wherein the composite layer comprises a graphene layer and a metal layer;

patterning the composite layer to form a second circuit layer;

forming a second shielding layer on the second circuit layer, wherein the second shielding layer comprises a second low-frequency shielding layer and a second high-frequency shielding layer;

forming a plurality of second openings on the second shielding layer to expose the second circuit layer;

filling a plurality of second silicone rubber materials in the plurality of second openings; and

a plurality of second conductive blind vias are formed in the plurality of second silicone rubber materials.

2. The method of manufacturing a circuit board according to claim 1, further comprising, before forming the second shield layer:

and forming a plurality of conductive holes in the second circuit layer, wherein the conductive holes are respectively and electrically connected with the first conductive blind holes.

3. The method of manufacturing a circuit board according to claim 1, wherein the step of forming the composite layer comprises:

forming an insulating layer on the first shielding layer and the plurality of first silicone rubber materials;

forming the graphene layer on the insulating layer; and

and forming the metal layer on the graphene layer.

4. The method of manufacturing a circuit board according to claim 3, further comprising:

forming at least one third opening on the second shielding layer and between the plurality of second openings to expose the insulating layer; and

filling a third silicone rubber material in the at least one third opening.

5. The method of manufacturing a circuit board of claim 1, wherein patterning the composite layer comprises:

removing the metal layer; and

the graphene layer is patterned using a plasma.

6. The method of manufacturing a circuit board according to claim 1, further comprising, prior to placing the electronic component in the recess:

forming an adhesive layer at the bottom of the groove; and

and placing the electronic element on the bonding layer.

7. The method of manufacturing a circuit board according to claim 1, wherein the step of forming the first shielding layer includes:

forming a first dielectric layer on the insulating substrate and the electronic element;

forming the first low-frequency shielding layer on the first dielectric layer; and

the first high-frequency shielding layer is formed on the first low-frequency shielding layer.

8. The method of manufacturing a circuit board according to claim 1, wherein the step of forming the second shielding layer includes:

forming a second dielectric layer on the second circuit layer;

forming the second low-frequency shielding layer on the second dielectric layer;

forming the second high-frequency shielding layer on the second low-frequency shielding layer; and

a third dielectric layer is formed on the second high frequency shield layer.

9. A circuit board, comprising:

an insulating substrate having a groove;

an electronic component disposed in the recess;

a first circuit layer disposed on a top surface of the electronic component;

a first shielding layer disposed on the insulating substrate and the electronic component, wherein the first shielding layer overlaps the electronic component;

a plurality of first silicone rubber materials disposed in the first shielding layer;

the first conductive blind holes are arranged in the first silicon rubber materials and are electrically connected with the first circuit layer;

the second circuit layer is arranged on the first shielding layer;

the second shielding layer is arranged on the second circuit layer;

a plurality of second silicone rubber materials disposed in the second shielding layer; and

the second conductive blind holes are arranged in the second conductive blind holes and are electrically connected with the second circuit layer.

10. The circuit board of claim 9, wherein the first shielding layer comprises:

the first dielectric layer is arranged on the insulating substrate and the electronic element;

the first low-frequency shielding layer is arranged on the first dielectric layer; and

a first high-frequency shielding layer disposed on the first low-frequency shielding layer.

11. The circuit board of claim 9, wherein the second shielding layer comprises:

the second medium layer is arranged on the second circuit layer;

the second low-frequency shielding layer is arranged on the second dielectric layer;

a second high-frequency shielding layer disposed on the second low-frequency shielding layer; and

and the third dielectric layer is arranged on the second high-frequency shielding layer.

12. The circuit board of claim 9, further comprising:

the plurality of conductive holes are arranged in the second circuit layer and are respectively and electrically connected with the plurality of first conductive blind holes.

13. The circuit board of claim 9, wherein the second wiring layer comprises at least one of graphene and copper.

14. The circuit board of claim 9, further comprising:

and a third silicone rubber material disposed in the second shielding layer and between the plurality of second silicone rubber materials.