阅读说明：本技术 具有内埋电子元件的线路板及其制作方法 (Circuit board with embedded electronic element and manufacturing method thereof ) 是由 李卫祥 于 2020-05-29 设计创作，主要内容包括：一种具有内埋电子元件的线路板的制作方法,包括以下步骤：提供线路基板,线路基板包括内层线路基板、第一中间线路层和第二中间线路层,线路基板中开设有一收容槽,收容槽的底部对应第二中间线路层；在收容槽中放置电子元件,电子元件包括电极；在第一中间线路层一侧形成第一可剥胶及第一外层线路层,第一外层线路层内嵌埋有至少一导电块,与第一可剥胶粘接的部分第一外层线路层为一第一待移除区；以及切割第一外层线路层并剥离第一可剥胶以及与第一可剥胶相粘接的第一外层线路层以形成第一开口,从而使得电子元件裸露出来,以得到具有内埋电子元件的线路板。本申请还提供一种具有内埋电子元件的线路板。(A method for manufacturing a circuit board with a buried electronic element comprises the following steps: providing a circuit substrate, wherein the circuit substrate comprises an inner layer circuit substrate, a first middle circuit layer and a second middle circuit layer, a containing groove is formed in the circuit substrate, and the bottom of the containing groove corresponds to the second middle circuit layer; placing an electronic component in the accommodating groove, wherein the electronic component comprises an electrode; forming a first peelable glue and a first outer layer circuit layer on one side of the first middle circuit layer, embedding at least one conductive block in the first outer layer circuit layer, wherein the part of the first outer layer circuit layer bonded with the first peelable glue is a first region to be removed; and cutting the first outer layer circuit layer and stripping the first peelable glue and the first outer layer circuit layer bonded with the first peelable glue to form a first opening, so that the electronic element is exposed to obtain the circuit board with the embedded electronic element. The application also provides a circuit board with the embedded electronic element.)

1. A method for manufacturing a circuit board with an embedded electronic element is characterized by comprising the following steps:

providing a circuit substrate, wherein the circuit substrate comprises an inner layer circuit substrate, and a first intermediate circuit layer and a second intermediate circuit layer which are formed on two opposite surfaces of the inner layer circuit substrate, an accommodating groove is formed in the circuit substrate, the accommodating groove penetrates through the first intermediate circuit layer and the inner layer circuit substrate, and the bottom of the accommodating groove corresponds to the second intermediate circuit layer;

placing an electronic component in the accommodating groove, wherein the electronic component comprises at least one electrode which protrudes out of the first intermediate circuit layer;

forming a first peelable glue and a first outer layer circuit layer on one side of the first middle circuit layer, so that the electrode is embedded in the first outer layer circuit layer, at least one conductive block is embedded in the first outer layer circuit layer, each conductive block corresponds to one electrode, and the conductive block is rectangular in shape and is used for electrically connecting the first outer layer circuit layer and the electrode, and the part of the first outer layer circuit layer bonded with the first peelable glue is a first region to be removed; and

and cutting the first outer layer circuit layer and peeling the first peelable glue and the first outer layer circuit layer bonded with the first peelable glue to form a first opening, so that the electronic element is exposed, and the circuit board with the embedded electronic element is obtained.

2. The method of claim 1, wherein the step of forming a first peelable adhesive and a first outer circuit layer on one side of the first middle circuit layer comprises the steps of:

providing a first copper foil layer and an insulating layer, wherein the first peelable glue is bonded on one surface of the insulating layer;

pressing the insulating layer and the first copper foil layer on one side of the first intermediate circuit layer, wherein the first peelable glue corresponds to the electronic element and is positioned between the first intermediate circuit layer and the insulating layer;

forming an opening in a portion of the first copper foil layer and the insulating layer corresponding to each of the electrodes such that the electrodes are exposed to the opening, the opening having a rectangular shape;

forming the conductive block in the opening; and

etching the first copper foil layer to form the first outer circuit layer.

3. The method of claim 2, wherein the step of forming the opening includes:

linearly cutting the first copper foil layer and the insulating layer along a direction perpendicular to the side wall of the electronic component to form the opening,

and the width of the opening is larger than that of the electrode adjacent to the opening along the extension direction of the circuit board.

4. The method according to claim 1, wherein a second peelable adhesive and a third peelable adhesive are provided in the circuit board, the second peelable adhesive is located between the inner circuit board and the first middle circuit layer, the second peelable adhesive is located between the inner circuit board and the second middle circuit layer, a portion of the first middle circuit layer bonded to the second peelable adhesive is a second region to be removed, and a portion of the second middle circuit layer bonded to the third peelable adhesive is a third region to be removed; the manufacturing method of the circuit board with the embedded electronic element further comprises the following steps:

removing the second region to be removed and the second peelable glue to form a second opening; and

and removing the third region to be removed and the third peelable glue to form a third opening.

5. The method for manufacturing a wiring board having an embedded electronic component according to claim 4, further comprising, before forming the second opening and the third opening:

forming a second outer circuit layer on one side of the second middle circuit layer, which is far away from the inner circuit substrate;

forming a first solder mask layer on one side of the first outer circuit layer, which is far away from the inner circuit substrate;

forming a second solder mask layer on one side of the second outer circuit layer, which is far away from the inner circuit substrate; and

after forming the second opening and the third opening, further comprising:

and forming a reinforcing plate on the second solder mask layer.

6. A wiring board having a buried electronic component, comprising:

the circuit board comprises an inner layer circuit board, a first middle circuit layer and a second middle circuit layer, wherein the first middle circuit layer and the second middle circuit layer are formed on two opposite surfaces of the inner layer circuit board;

the electronic element is positioned in the accommodating groove and comprises at least one electrode, and the electrode protrudes out of the first intermediate circuit layer; and

the first outer layer circuit layer is formed on one side of the first middle circuit layer, at least one conductive block is embedded in the first outer layer circuit layer, each conductive block is arranged corresponding to one electrode to be electrically connected with the first outer layer circuit layer and the electrode, a first opening is formed in the position, corresponding to the electronic element, of the first outer layer circuit layer, and penetrates through the first outer layer circuit layer to expose the electronic element.

7. The wiring board with embedded electronic components according to claim 6, wherein the wiring board with embedded electronic components further comprises:

the conductive block is rectangular and extends to the peripheral area of the electronic element perpendicular to the side wall of the electronic element, and the width of the conductive block is larger than that of the electrode adjacent to the conductive block along the extending direction of the circuit board.

8. The circuit board of claim 7, wherein the periphery of the electronic component provided with the electrodes is embedded in the first outer circuit layer, and the surface of the electronic component surrounded by the periphery is exposed to the first opening.

9. The wiring board with embedded electronic components as claimed in claim 6, wherein the wiring board with embedded electronic components further has a second opening and a third opening, the second opening penetrates through the first outer layer circuit layer and the first middle circuit layer, the bottom of the second opening corresponds to the inner layer circuit substrate, the third opening penetrates through the second middle circuit layer, and the bottom of the third opening corresponds to the inner layer circuit substrate.

10. The wiring board with embedded electronic components according to claim 9, wherein the wiring board with embedded electronic components further comprises:

a second outer layer circuit layer located on one side of the second middle circuit layer;

the first solder mask layer is positioned on one side of the outer circuit layer;

the second solder mask layer is positioned on one side of the first outer layer circuit layer; and

and the reinforcing plate is formed on the second welding-proof layer.

Technical Field

The invention relates to the technical field of circuit boards, in particular to a circuit board with an embedded electronic element and a manufacturing method thereof.

Background

The rigid-flex board (R-F) is designed by combining a rigid circuit board (PCB) and a flexible circuit board (FPC), and has the advantages of thinness, lightness, easy assembly, better electrical signal transmission and product reliability, etc. Currently, a sensor in a camera module is electrically connected to a pad of an R-F module by a wire bonding (gold bonding) method. However, the flatness of the bonding pad surface or the process parameters of the bonding wire affect the robustness of the bonding wire connection, which may cause the wire to break and fall off. In addition, the bonding pads are usually surface treated prior to wire bonding, which adds to some extent to the cost of production.

Disclosure of Invention

In view of the above, the present invention provides a method for manufacturing a circuit board with embedded electronic components, which can prevent gold wires from breaking and falling off, and can reduce the production cost.

In addition, it is necessary to provide a circuit board with embedded electronic components that can prevent the gold wires from breaking and falling off.

A method for manufacturing a circuit board with a buried electronic element comprises the following steps:

providing a circuit substrate, wherein the circuit substrate comprises an inner layer circuit substrate, and a first intermediate circuit layer and a second intermediate circuit layer which are formed on two opposite surfaces of the inner layer circuit substrate, an accommodating groove is formed in the circuit substrate, the accommodating groove penetrates through the first intermediate circuit layer and the inner layer circuit substrate, and the bottom of the accommodating groove corresponds to the second intermediate circuit layer;

placing an electronic component in the accommodating groove, wherein the electronic component comprises at least one electrode which protrudes out of the first intermediate circuit layer;

forming a first peelable glue and a first outer layer circuit layer on one side of the first middle circuit layer, so that the electrode is embedded in the first outer layer circuit layer, at least one conductive block is embedded in the first outer layer circuit layer, each conductive block corresponds to one electrode, and the conductive block is rectangular in shape and is used for electrically connecting the first outer layer circuit layer and the electrode, and the part of the first outer layer circuit layer bonded with the first peelable glue is a first region to be removed; and

and cutting the first outer layer circuit layer and peeling the first peelable glue and the first outer layer circuit layer bonded with the first peelable glue to form a first opening, so that the electronic element is exposed, and the circuit board with the embedded electronic element is obtained.

A circuit board with an embedded electronic component comprises a circuit substrate, an electronic component and a first outer circuit layer. The circuit substrate comprises an inner layer circuit substrate, a first middle circuit layer and a second middle circuit layer, wherein the first middle circuit layer and the second middle circuit layer are formed on two opposite surfaces of the inner layer circuit substrate; the electronic element is positioned in the accommodating groove and comprises at least one electrode, and the electrode protrudes out of the first intermediate circuit layer; the first outer layer circuit layer is formed on one side of the first middle circuit layer, at least one conductive block is embedded in the first outer layer circuit layer, each conductive block is arranged corresponding to one electrode to electrically connect the first outer layer circuit layer and the electrode, the first outer layer circuit layer is provided with a first opening corresponding to the electronic element, and the first opening penetrates through the first outer layer circuit layer to expose the electronic element.

According to the invention, the conductive block is formed in the electrode area of the electronic element, so that the conductive block is electrically connected with the first outer layer circuit layer and the electrode, and the problems of gold wire breakage and falling after gold wire bonding are avoided. Meanwhile, the step of carrying out surface treatment on the welding pad of the conducting circuit layer is omitted, and the production cost is favorably reduced.

Drawings

Fig. 1 is a schematic structural diagram of a circuit substrate according to a preferred embodiment of the invention.

Fig. 2 is a schematic view showing a structure after electronic components are mounted in the housing tub shown in fig. 1.

Fig. 3 is a schematic structural view illustrating a first copper foil layer, a third insulating layer, the circuit substrate shown in fig. 2, a fourth insulating layer and a second copper foil layer sequentially stacked according to a preferred embodiment of the present invention.

Fig. 4 is a schematic structural view of the first copper foil layer, the third insulating layer, the circuit substrate, the fourth insulating layer and the second copper foil layer shown in fig. 3 after lamination.

Fig. 5 is a schematic view of the structure of fig. 4 after the opening is filled with the conductive paste.

Fig. 6 is a schematic structural diagram of a circuit board with embedded electronic components, which is obtained by forming a first solder mask layer and a second solder mask layer on the first outer circuit layer and the second outer circuit layer shown in fig. 5, respectively, and opening the cover and forming a reinforcing plate.

Description of the main elements

Wiring board 100 with embedded electronic component

Circuit board 10

Inner layer circuit board 11

First base layer 111

First inner wiring layer 112

First cover film 113

First glue layer 1131

First cover layer 1132

Second inner wiring layer 114

Second coverlay film 115

Second glue layer 1151

Second cladding layer 1152

First intermediate circuit substrate 12

First insulating layer 121

First intermediate circuit layer 122

Second intermediate circuit board 13

Second insulating layer 131

Second intermediate circuit layer 132

Receiving groove 14

Third conductive part 15

A fourth conductive part 16

A fifth conductive part 17

Second peelable glue 20

Third peelable glue 21

First peelable glue 22

First region to be removed 23

Second region to be removed 24

Third region to be removed 25

Electronic component 30

Electrode 301

First copper foil layer 40

Second copper foil layer 41

First outer circuit layer 42

Pad 421

Second outer wiring layer 43

Third insulating layer 50

Fourth insulating layer 51

Opening 52

Conductive block 53

First blind hole 60

Second blind hole 61

First conductive part 62

Second conductive part 63

First solder mask layer 70

Second solder mask layer 71

First opening 80

Second opening 81

Third opening 82

Reinforcing plate 90

Third adhesive layer 91

Soft board area I

Hardboard zone II

The following detailed description will further illustrate the invention in conjunction with the above-described figures.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

To further explain the technical means and effects of the present invention adopted to achieve the intended purpose, the present invention will be described in detail with reference to the accompanying drawings and preferred embodiments.

The preferred embodiment of the invention provides a method for manufacturing a circuit board with an embedded electronic element, which comprises the following steps:

in step S11, please refer to fig. 1, a circuit substrate 10 is provided.

In the present embodiment, the wiring substrate 10 includes an inner layer wiring substrate 11 and a first intermediate wiring substrate 12 and a second intermediate wiring substrate 13 formed on opposite surfaces of the inner layer wiring substrate 11. The inner circuit substrate 11 is a flexible circuit board, and the first intermediate circuit substrate 12 and the second intermediate circuit substrate 13 are both rigid circuit boards.

In this embodiment, the inner circuit board 11 includes a first base layer 111, a first inner circuit layer 112 and a first cover film 113 sequentially formed on one surface of the first base layer 111, and a second inner circuit layer 114 and a second cover film 115 sequentially formed on the other surface of the first base layer 111. The first cover film 113 includes a first adhesive layer 1131 formed on the first inner circuit layer 112 and a first cover layer 1132 formed on the first adhesive layer 1131. The second coverlay film 115 includes a second glue layer 1151 formed on the second inner wiring layer 114 and a second cover layer 1152 formed on the second glue layer 1151.

The material of the first base layer 111, the first cover layer 1132 and the second cover layer 1152 may be selected from one of Polyimide (PI), Liquid Crystal Polymer (LCP), Polyethylene Terephthalate (PET), Polyethylene Naphthalate (PEN), and other resins. The first glue layer 1131 and the second glue layer 1151 may be conventional pure glue.

In this embodiment, the first base layer 111 is made of polyimide, the first adhesive layer 1131 and the second adhesive layer 1151 are both made of acrylic hot melt adhesive, and the first cover layer 1132 and the second cover layer 1152 are both made of polyimide.

The first intermediate circuit substrate 12 includes a first insulating layer 121 and a first intermediate circuit layer 122 sequentially formed on the first cover layer 1132. The second intermediate wiring substrate 13 includes a second insulating layer 131 and a second intermediate wiring layer 132 sequentially formed on the second cover layer 1152.

The material of the first insulating layer 121 and the second insulating layer 131 may be at least one selected from polypropylene (PP), Polyethylene Terephthalate (PET), Polyethylene Naphthalate (PEN), and other resins.

In this embodiment, the first insulating layer 121 and the second insulating layer 131 are made of polypropylene.

The circuit substrate 10 is provided with a receiving groove 14. In this embodiment, the receiving groove 14 penetrates the first intermediate circuit board 12 and the inner layer circuit board 11, and the bottom of the receiving groove 14 corresponds to the second insulating layer 131.

In the present embodiment, the wiring substrate 10 is further provided with a third conductive portion 15, a fourth conductive portion 16, and a fifth conductive portion 17. The third conductive part 15 is used to electrically connect the first inner circuit layer 112 and the first middle circuit layer 122, the fourth conductive part 16 is used to electrically connect the first inner circuit layer 112 and the second inner circuit layer 114, and the fifth conductive part 17 is used to electrically connect the second inner circuit layer 114 and the second middle circuit layer 132.

The circuit substrate 10 is further provided with a second peelable glue 20 and a third peelable glue 21. The second peelable glue 20 is adhered between the first insulating layer 121 and the inner circuit board 11, and the third peelable glue 21 is adhered between the second insulating layer 131 and the inner circuit board 11.

Of course, in other embodiments, the number of conductive line layers in the circuit substrate 10 may be changed according to actual circumstances.

In step S12, referring to fig. 2, the electronic component 30 is mounted in the accommodating cavity 14, and the electronic component 30 includes at least one electrode 301. Wherein the electrode 301 protrudes from the first intermediate wiring layer 122.

Specifically, the electronic component 30 may be a photosensitive chip in a lens module. The photosensitive chip includes a photosensitive region (not shown) located at the center of the photosensitive chip. The electrodes 301 are disposed around the photosensitive area.

In step S13, please refer to fig. 3, a first copper foil layer 40, a second copper foil layer 41, a third insulating layer 50 and a fourth insulating layer 51 are provided.

The first peelable glue 22 is adhered to one surface of the third insulating layer 50. The materials of the third insulating layer 50 and the fourth insulating layer 51 can be the same as those of the first insulating layer 121 and the second insulating layer 131, and are not described in detail herein.

In step S14, referring to fig. 4, the third insulating layer 50 and the first copper foil layer 40 are laminated on one side of the first middle circuit layer 122, such that the first peelable glue 22 corresponds to the electronic component 30 and is located between the third insulating layer 50 and the electronic component 30, and the fourth insulating layer 51 and the second copper foil layer 41 are laminated on one side of the second middle circuit layer 132.

Step S15, forming an opening 52 in a portion of the first copper foil layer 40 and the third insulating layer 50 corresponding to each of the electrodes 301, wherein the first copper foil layer 40 and the third insulating layer 50 are linearly cut along a direction perpendicular to a sidewall of the electronic component 30 on a surface of the first copper foil layer 40 away from the inner circuit substrate 11 to form the opening 52, so that the electrode 301 is exposed to the opening 52. Wherein the electrode 301 is embedded in the third insulating layer 50 and the first copper foil layer 40.

The opening 52 is rectangular in shape. The width of the opening 52 is defined as the dimension of the opening 52 along the extending direction of the circuit substrate 10. In this embodiment, the width of the opening 52 is larger than the width of the electrode 301 adjacent to the opening 52, and one sidewall (not shown) of the opening 52 is flush with one sidewall (not shown) of the electrode 301.

In this embodiment, the bottom of the opening 52 is flush with the surface of the electrode 301 adjacent to the opening 52. It is understood that the opening 52 extends through the first copper foil layer 40 and does not extend through the third insulating layer 50.

Wherein the opening 52 may be formed by laser cutting. In this embodiment, the apertures 52 are formed by CO2 laser linear cutting.

Step S16 is to form a first blind via 60 in the first copper foil layer 40 and the third insulating layer 50, and form a second blind via 61 in the second copper foil layer 41 and the fourth insulating layer 51.

The first blind via 60 penetrates the first copper foil layer 40 and the third insulating layer 50, and the second blind via 61 penetrates the second copper foil layer 41 and the fourth insulating layer 51. In the present embodiment, the first blind hole 60 and the second blind hole 61 each have a substantially trapezoidal cross section.

Wherein the first blind hole 60 and the second blind hole 61 can be formed by laser cutting. In the present embodiment, the first blind hole 60 and the second blind hole 61 are both filled with CO₂Laser diffraction is performed.

In step S17, referring to fig. 5, a conductive block 53 is formed in the opening 52, and a first conductive portion 62 and a second conductive portion 63 are formed in the first blind via 60 and the second blind via 61, respectively.

Specifically, the conductive block 53 is formed by plating copper or filling conductive paste in the opening 52, and the first conductive portion 62 and the second conductive portion 63 are formed by plating copper in the first blind via 60 and the second blind via 61, respectively. The conductive blocks 53 are connected to the first outer layer circuit layer 42 and embedded in the first outer layer circuit layer 42, and each conductive block 53 corresponds to one of the electrodes 301. It will be appreciated that the width of the conductive block 53 corresponds to the width of the opening 52.

In this embodiment, the opening 52 is filled with a conductive paste. The conductive paste can be copper paste or tin paste. Specifically, the conductive paste in the opening 52 is solder paste.

It is understood that, in this embodiment, the conductive paste in the opening 52 is bonded not only to the electrode 301 but also to the bottom of the opening 52 (i.e., the third insulating layer 50). That is, the width of the bottom of the conductive paste in the opening 52 is larger than the width of the electrode 301 adjacent thereto. This is advantageous for enhancing the adhesion between the conductive paste and the electrode 301.

The conductive block 53 is used to electrically connect the first copper foil layer 40 and the electrode 301, the first conductive part 62 is used to electrically connect the first copper foil layer 40 and the first intermediate circuit layer 122, and the second conductive part 63 is used to electrically connect the second copper foil layer 41 and the second intermediate circuit layer 132.

In step S18, the first copper foil layer 40 and the second copper foil layer 41 are etched to form a first outer circuit layer 42 and a second outer circuit layer 43, respectively.

The first outer circuit layer 42 and the second outer circuit layer 43 can be formed by etching through exposure and development.

It is understood that the conductive block 53 is used to electrically connect the first outer layer circuit layer 42 and the electrode 301, the first conductive part 62 is used to electrically connect the first outer layer circuit layer 42 and the first middle circuit layer 122, and the second conductive part 63 is used to electrically connect the second outer layer circuit layer 43 and the second middle circuit layer 132.

A portion of the third insulation layer 50 and a portion of the first outer circuit layer 42 adhered to the first peelable adhesive 22 are a first region to be removed 23. A portion of the first insulating layer 121, a portion of the first middle circuit layer 122, a portion of the third insulating layer 50, and a portion of the first outer circuit layer 42 adhered to the second peelable adhesive 20 is a second region to be removed 24. A portion of the second insulating layer 131, a portion of the second middle circuit layer 132, a portion of the fourth insulating layer 51, and a portion of the second outer circuit layer 43 adhered to the third peelable glue 21 is a third region to be removed 25.

In step S19, referring to fig. 6, a first solder mask layer 70 and a second solder mask layer 71 are formed on the first outer circuit layer 42 and the second outer circuit layer 43, respectively.

A portion of the first outer circuit layer 42 is exposed to the first solder mask layer 70 to form a pad 421.

The first solder mask layer 70 and the second solder mask layer 71 can be made of solder mask ink, such as green oil.

Step S20, peeling the first peelable glue 22 and the first area to be removed 23 adhered to the first peelable glue 22 to form a first opening 80, peeling the second peelable glue 20 and the second area to be removed 24 adhered to the second peelable glue 20 to form a second opening 81, and peeling the third peelable glue 21 and the third area to be removed 25 adhered to the third peelable glue 21 to form a third opening 82.

The second opening 81 and the third opening 82 are both used for exposing a part of the inner circuit substrate 11, and the positions of the second opening 81 and the third opening 82 on two sides of the inner circuit substrate 11 correspond to each other. The exposed inner layer circuit substrate 11 forms a flexible board area I of the rigid-flexible combined board, and two sides of the flexible board area I are rigid board areas II.

In step S21, a reinforcing plate 90 is formed on the second solder resist layer 71, thereby obtaining the wiring board 100 with embedded electronic components.

The reinforcing plate 90 is bonded to the second solder mask layer 71 through a third adhesive layer 91. The reinforcing plate 90 and the third glue layer 91 are both provided with fourth openings (not shown) corresponding to the third openings 82.

The reinforcing plate 90 is used to enhance the stability of the circuit board 100 with embedded electronic components. Specifically, the reinforcing plate 90 is used for supporting the electronic component 30. The material of the reinforcing plate 90 may be metal, such as iron metal. The material of the third adhesive layer 91 may be the same as the material of the first adhesive layer 1131 and the second adhesive layer 1151, and is not described in detail herein.

In the present embodiment, the wiring board 100 having the embedded electronic component is a rigid-flex board. In other embodiments, the wiring board 100 with embedded electronic components may also be a flexible board.

It should be noted that, in step S13, the number of the second copper foil layer 41 and the fourth insulating layer 51 is not limited to one, and a larger number of the second copper foil layer 41 and the fourth insulating layer 51 may be provided, so that the circuit board 100 with the embedded electronic component manufactured later has a larger number of conductive trace layers.

Referring to fig. 6, a circuit board 100 with embedded electronic components is further provided in the preferred embodiment of the present invention, where the circuit board 100 with embedded electronic components includes a circuit substrate 10, an electronic component 30, a third insulating layer 50, a first outer circuit layer 42, a fourth insulating layer 51, a second outer circuit layer 43, a first solder mask layer 70, a second solder mask layer 71, and a reinforcing plate 90.

In the present embodiment, the wiring substrate 10 includes an inner layer wiring substrate 11 and a first intermediate wiring substrate 12 and a second intermediate wiring substrate 13 formed on opposite surfaces of the inner layer wiring substrate 11. The inner circuit substrate 11 is a flexible circuit board, and the first intermediate circuit substrate 12 and the second intermediate circuit substrate 13 are both rigid circuit boards.

In this embodiment, the inner circuit board 11 includes a first base layer 111, a first inner circuit layer 112 and a first cover film 113 sequentially formed on one surface of the first base layer 111, and a second inner circuit layer 114 and a second cover film 115 sequentially formed on the other surface of the first base layer 111. The first cover film 113 includes a first adhesive layer 1131 formed on the first inner circuit layer 112 and a first cover layer 1132 formed on the first adhesive layer 1131. The second coverlay film 115 includes a second glue layer 1151 formed on the second inner wiring layer 114 and a second cover layer 1152 formed on the second glue layer 1151.

In this embodiment, the first base layer 111 is made of polyimide, the first adhesive layer 1131 and the second adhesive layer 1151 are both made of acrylic hot melt adhesive, and the first cover layer 1132 and the second cover layer 1152 are both made of polyimide.

The first intermediate circuit substrate 12 includes a first insulating layer 121 and a first intermediate circuit layer 122 sequentially formed on the first cover layer 1132. The second intermediate wiring substrate 13 includes a second insulating layer 131 and a second intermediate wiring layer 132 sequentially formed on the second cover layer 1152.

In this embodiment, the first insulating layer 121 and the second insulating layer 131 are made of polypropylene.

In the present embodiment, the wiring substrate 10 is further provided with a third conductive portion 15, a fourth conductive portion 16, and a fifth conductive portion 17. The third conductive part 15 is used to electrically connect the first inner circuit layer 112 and the first middle circuit layer 122, the fourth conductive part 16 is used to electrically connect the first inner circuit layer 112 and the second inner circuit layer 114, and the fifth conductive part 17 is used to electrically connect the second inner circuit layer 114 and the second middle circuit layer 132.

Of course, in other embodiments, the number of conductive line layers in the circuit substrate 10 may be changed according to actual circumstances.

The electronic component 30 is mounted in the housing groove 14. In this embodiment, the receiving groove 14 penetrates the first intermediate circuit board 12 and the inner layer circuit board 11, and the bottom of the receiving groove 14 corresponds to the second insulating layer 131.

In the present embodiment, the electronic component 30 includes at least one electrode 301. Wherein the electrode 301 protrudes from the first intermediate wiring layer 122. Specifically, the electronic component 30 may be a photosensitive chip in a lens module. The photosensitive chip includes a photosensitive region (not shown) located at the center of the photosensitive chip. The electrodes 301 are disposed around the photosensitive area.

The third insulating layer 50 and the first outer-layer wiring layer 42 are sequentially formed on one side of the first intermediate wiring layer 122.

The material of the third insulating layer 50 may be the same as the material of the first insulating layer 121 and the second insulating layer 131, and will not be described in detail herein.

The third insulating layer 50 and the first outer circuit layer 42 have openings 52 at positions corresponding to the electrodes 301. The electrode 301 is exposed to the opening 52.

Wherein the opening 52 is rectangular in shape. The width of the opening 52 is defined as the dimension of the opening 52 along the extending direction of the circuit substrate 10. In this embodiment, the width of the opening 52 is larger than the width of the electrode 301 adjacent to the opening 52, and one sidewall (not shown) of the opening 52 is flush with one sidewall (not shown) of the electrode 301. The electrode 301 is embedded in the third insulating layer 50.

In this embodiment, the bottom of the opening 52 is flush with the surface of the electrode 301 adjacent to the opening 52. The opening 52 extends through the first copper foil layer 40 and does not extend through the third insulating layer 50.

The openings 52 are filled with a conductive material to form conductive bumps 53. Wherein, the conductive material can be a copper plating material or a conductive paste. In this embodiment, the opening 52 is filled with a conductive paste. The conductive paste can be copper paste or tin paste. Specifically, the conductive paste in the opening 52 is solder paste. The conductive block 53 is used for electrically connecting the first outer circuit layer 42 and the electrode 301.

The conductive bumps 53 are rectangular, and the conductive bumps 53 extend perpendicular to the side walls of the electronic component 30 toward the peripheral area of the electronic component 30, that is, at least one conductive bump 53 is partially disposed on the surface of the electronic component 30, and the rest of the conductive bumps 53 protrude from the electronic component 30. In addition, when the number of the conductive bumps 53 is plural, the plural conductive bumps 53 surround the electronic component 30 and the periphery of the first opening 80.

Further, the periphery of the electronic element 30 provided with the electrode 301 is embedded in the first outer circuit layer 42, the surface of the electronic element 30 surrounded by the periphery is exposed to the first opening 80, and the electrode 301 is not exposed to the first opening 80. Referring to fig. 6 again, it can be understood that the distance between the electrodes 301 disposed on the two opposite sides of the electronic element 30 is greater than or equal to the width of the first opening 80 in the same direction.

The conductive blocks 53 are connected to the first outer circuit layer 42 and embedded in the first outer circuit layer 42, and each conductive block 53 corresponds to one of the electrodes 301. It is understood that, in this embodiment, the conductive paste in the opening 52 is bonded not only to the electrode 301 but also to the bottom of the opening 52 (i.e., the third insulating layer 50). That is, the width of the bottom of the conductive paste in the opening 52 is larger than the width of the electrode 301 adjacent thereto. This is advantageous for enhancing the adhesion between the conductive paste and the electrode 301.

The third insulating layer 50 and the first outer circuit layer 42 have first openings 80 at positions corresponding to the electronic components 30. Specifically, the first opening 80 corresponds to the photosensitive region of the electronic component 30. The first opening 80 penetrates the third insulating layer 50 and the first outer circuit layer 42.

The fourth insulating layer 51 and the second outer-layer wiring layer 43 are sequentially formed on the second intermediate wiring layer 132 side.

The material of the fourth insulating layer 51 may be the same as the material of the first insulating layer 121 and the second insulating layer 131, and will not be described in detail herein.

The wiring board 100 with embedded electronic components is further provided with a second opening 81 and a third opening 82. The second opening 81 penetrates through the first outer circuit layer 42, the third insulating layer 50, and the first intermediate circuit board 12, and the bottom of the second opening 81 corresponds to the inner circuit board 11. The third opening 82 penetrates through the second outer circuit layer 43, the fourth insulating layer 51 and the second intermediate circuit substrate 13, and the bottom of the third opening 82 corresponds to the inner circuit substrate 11.

The second opening 81 and the third opening 82 are both used for exposing a part of the inner circuit substrate 11, and the positions of the second opening 81 and the third opening 82 on two sides of the inner circuit substrate 11 correspond to each other. The exposed inner layer circuit substrate 11 forms a flexible board area I of the rigid-flexible combined board, and two sides of the flexible board area are hard board areas II.

The wiring board 100 having the embedded electronic component is further provided with a first conductive part 62 and a second conductive part 63. The first conductive part 62 is used to electrically connect the first outer circuit layer 42 and the first middle circuit layer 122, and the second conductive part 63 is used to electrically connect the second outer circuit layer 43 and the second middle circuit layer 132. In the present embodiment, the cross sections of the first conductive portion 62 and the second conductive portion 63 are substantially trapezoidal.

The first solder mask layer 70 and the second solder mask layer 71 are formed on the first outer circuit layer 42 and the second outer circuit layer 43, respectively. The first solder mask layer 70 and the second solder mask layer 71 can be made of solder mask ink, such as green oil. A portion of the first outer circuit layer 42 is exposed to the first solder mask layer 70 to form a pad 421.

The reinforcing plate 90 is bonded to the second solder mask layer 71 through a third adhesive layer 91. The reinforcing plate 90 and the third glue layer 91 are both provided with fourth openings (not shown) corresponding to the third openings 82.

The reinforcing plate 90 is used to enhance the stability of the circuit board 100 with embedded electronic components. Specifically, the reinforcing plate 90 is used for supporting the electronic component 30. The material of the reinforcing plate 90 may be metal, such as iron metal. The material of the third adhesive layer 91 may be the same as the material of the first adhesive layer 1131 and the second adhesive layer 1151, and is not described in detail herein.

In the present embodiment, the wiring board 100 having the embedded electronic component is a rigid-flex board. In other embodiments, the wiring board 100 with embedded electronic components may also be a flexible board.

It should be noted that a greater number of conductive circuit layers may be disposed between the second intermediate circuit layer 132 and the second outer circuit layer 43, so that the resulting circuit board 100 with embedded electronic components has a greater number of conductive circuit layers.

According to the invention, the opening 52 is formed by cutting in the area of the electrode 301 of the electronic element 30, and the conductive block 53 is formed by plating copper or filling conductive paste in the opening 52, so that the conductive block 53 is electrically connected with the first outer layer circuit layer 42 and the electrode 301, and the problem that a gold wire is likely to break and fall off after gold wire bonding is avoided. Meanwhile, the step of carrying out surface treatment on the welding pad of the conducting circuit layer is omitted, and the production cost is favorably reduced.

The above description is only an optimized embodiment of the present invention, but the present invention is not limited to this embodiment in practical application. Other modifications and variations to the technical concept of the present invention should be apparent to those skilled in the art, and they should be construed as within the scope of the present invention.