Embedded circuit board and method of manufacturing the same

Abstract

A manufacturing method of an embedded circuit board, comprising the following steps: providing an inner layer circuit substrate, which is provided with a through groove; attaching a bearing plate to the inner layer circuit substrate to seal one end of the through groove; providing an electronic component module, which comprises a body, at least one electronic component, a first adhesive layer and a second adhesive layer, the body is provided with a recess, the at least one electronic component is fixed to the bottom wall of the recess through the first adhesive layer, and the second adhesive layer is filled in the recess and covers the at least one electronic component together with the first adhesive layer; placing the electronic component module in the through groove; pressing a first base layer on one side of the inner layer circuit substrate; removing the bearing plate; and pressing a second base layer on the other side of the inner layer circuit substrate, wherein the first base layer and the second base layer fill the through groove and cover the electronic component module together. The application also provides an embedded circuit board manufactured by the above method.

Description

Technical Field

[0001] This application relates to the field of circuit board technology, and in particular to an embedded circuit board and its manufacturing method. Background Technology

[0002] In recent years, electronic products have been widely used in daily work and life, and the demand for miniaturization, multifunctionality, and high performance is increasing. As a major component of electronic products, the circuit board occupies a large space, so its size greatly affects the size of the electronic product. Embedding electronic components (such as resistors and capacitors) inside the circuit board helps reduce the overall thickness of the circuit board, thereby reducing the thickness of the electronic product.

[0003] The typical procedure for embedding electronic components is as follows: First, an inner circuit board is fabricated, and a groove is formed on the inner circuit board; then, the electronic component is placed in the groove, and additional layers are added. However, during the addition of layers, the electronic component is prone to irregular misalignment, which increases the difficulty of precise alignment between the subsequent blind vias and soldered terminals. Summary of the Invention

[0004] In view of this, it is necessary to provide an embedded circuit board that can solve the above-mentioned technical problems and a method for manufacturing the same.

[0005] The first aspect of this application provides a method for manufacturing an embedded circuit board, comprising the following steps:

[0006] An inner circuit board is provided, the inner circuit board including a first surface and a second surface disposed opposite to each other;

[0007] A through groove is formed on the inner circuit board, the through groove connecting the first surface and the second surface;

[0008] A support plate is attached to the second surface to seal one end of the through groove;

[0009] An electronic component module is provided, the electronic component module including a body, at least one electronic component, a first adhesive layer and a second adhesive layer, the body having a groove, the at least one electronic component being fixed to the bottom wall of the groove by the first adhesive layer, and the second adhesive layer filling the groove and together with the first adhesive layer covering the at least one electronic component;

[0010] The electronic component module is placed in the through groove, wherein the electronic component module is bonded to the carrier plate;

[0011] A first base layer is pressed onto the first surface;

[0012] Remove the support plate;

[0013] A second base layer is pressed onto the second surface, wherein the first base layer and the second base layer fill the through groove and together cover the electronic component module;

[0014] A first conductive line layer is formed on the surface of the first base layer opposite to the first surface to obtain a first circuit substrate, and a second conductive line layer is formed on the surface of the second base layer opposite to the second surface to obtain a second circuit substrate.

[0015] A second aspect of this application provides an embedded circuit board, including an inner circuit board, an electronic component module, a first circuit board, and a second circuit board. The inner circuit board includes a first surface and a second surface disposed opposite to each other and has a through groove passing through the first surface and the second surface. The electronic component module is housed in the through groove. The electronic component module includes a body, at least one electronic component, a first adhesive layer, and a second adhesive layer. The body has a groove. The at least one electronic component is fixed to the bottom wall of the groove by the first adhesive layer, and the second adhesive layer fills the groove and together with the first adhesive layer covers the at least one electronic component. The first circuit board includes a first base layer and a first conductive line layer stacked together. The second circuit board includes a second base layer and a second conductive line layer stacked together. The first base layer covers the first surface, the second base layer covers the second surface, and the first base layer and the second base layer fill the through groove to jointly cover the electronic component module.

[0016] In the embedded circuit board and its manufacturing method provided in this application, the electronic component module is pre-bonded and positioned on the carrier plate, reducing the risk of displacement caused by dielectric material flow during the subsequent bonding process; and the electronic component is pre-fixed in the groove by the first adhesive layer, further reducing the risk of displacement caused by adhesive flow during the subsequent filling process. Furthermore, integrating multiple electronic components into the electronic component module simplifies the process flow. Attached Figure Description

[0017] Figure 1 This is a cross-sectional schematic diagram of an inner layer circuit board provided in one embodiment of this application.

[0018] Figure 2 In order to be in Figure 1 The diagram shows a cross-section of the inner circuit board after a through slot has been created.

[0019] Figure 3 In order to be in Figure 1 A schematic cross-sectional view of one surface of the inner circuit board after the carrier plate is attached.

[0020] Figure 4 This is a top view of an insulating plate provided according to one embodiment of this application.

[0021] Figure 5 for Figure 4 A schematic cross-sectional view of the insulating plate shown.

[0022] Figure 6 In order to be in Figure 5 The diagram shows a cross-section of the body after a groove has been formed.

[0023] Figure 7 To house electronic components Figure 6 A schematic diagram of the cross-section of the groove shown.

[0024] Figure 8 In order to be in Figure 7 A schematic diagram of the cross-section after the groove is filled with glue.

[0025] Figure 9 For separation Figure 8 The diagram shows a cross-sectional view of the insulating board after multiple electronic component modules have been assembled.

[0026] Figure 10 To be Figure 8 The electronic component module shown is placed in Figure 3 A schematic diagram of the cross-section after passing through the groove.

[0027] Figure 11 In order to be in Figure 10 A schematic cross-sectional view of the inner circuit board after the first base layer is pressed onto the side away from the carrier plate shown.

[0028] Figure 12 To remove Figure 11 The diagram shows a cross-section behind the bearing plate.

[0029] Figure 13 In order to be in Figure 12 The diagram shows a cross-sectional view of the inner circuit board after the second base layer is pressed onto the side away from the first base layer.

[0030] Figure 14 In order to be in Figure 13 A schematic diagram of the cross-section after a blind hole is formed on the structure shown.

[0031] Figure 15 In order to be in Figure 14 A schematic cross-sectional view of the blind hole after the first conductive structure has been formed.

[0032] Figure 16 In order to be in Figure 15 The diagram shows a cross-sectional view after the first conductive line layer and the second conductive line layer are formed on the first base layer and the second base layer, respectively.

[0033] Figure 17 In order to be in Figure 16 The diagram shows a cross-sectional view after the third and fourth circuit substrates are formed on the first and second conductive lines, respectively.

[0034] Explanation of main component symbols

[0035] Inner circuit board 10

[0036] First surface 11

[0037] Second surface 12

[0038] Through slot 101

[0039] Bearing plate 20

[0040] Insulating board 31

[0041] Ontology 311

[0042] Groove 301

[0043] First adhesive layer 32

[0044] Electronic Components 33

[0045] Second adhesive layer 35

[0046] Electronic component module 30

[0047] First grassroots level 41

[0048] Second grassroots level 51

[0049] Blind hole 110

[0050] First metal layer 42

[0051] Second metal layer 52

[0052] First conductive circuit layer 43

[0053] Second conductive circuit layer 53

[0054] First circuit board 40

[0055] Second circuit board 50

[0056] Third circuit board 60

[0057] Third grassroots level 61

[0058] Third conductive layer 63

[0059] Fourth circuit board 70

[0060] Fourth grassroots level 71

[0061] Fourth conductive layer 73

[0062] Second conductive structure 113

[0063] Embedded circuit board 100

[0064] The following detailed description, in conjunction with the accompanying drawings, will further illustrate this application. Detailed Implementation

[0065] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0066] One embodiment of this application provides a method for manufacturing an embedded circuit board, which includes the following steps.

[0067] Step S1, please refer to Figure 1 An inner layer circuit board 10 is provided. The inner layer circuit board 10 includes a first surface 11 and a second surface 12 disposed opposite to each other.

[0068] The inner circuit board 10 is a circuit board with conductive lines formed thereon. The inner circuit board 10 includes at least one conductive line layer and at least one dielectric layer. Each dielectric layer is disposed between two adjacent conductive line layers. A first conductive structure is formed in each dielectric layer, and two adjacent conductive line layers are electrically connected to each other through the first conductive structure.

[0069] The dielectric layer can be made of a rigid insulating material, such as FR-4 grade polyimide, polypropylene, liquid crystal polymer, polyetheretherketone, polyethylene terephthalate, and polyethylene naphthalate. Alternatively, the dielectric layer can be made of a flexible insulating material, such as polyimide, polypropylene, liquid crystal polymer, polyetheretherketone, polyethylene terephthalate, and polyethylene naphthalate. The conductive circuit layer can be made of, but is not limited to, copper, gold, and silver.

[0070] The inner circuit board 10 can be manufactured using existing circuit board manufacturing methods. For example, a core layer board can be manufactured first, and then layers can be added to both sides of the core layer board to obtain the inner circuit board.

[0071] For step S2, please refer to [link / reference]. Figure 2 A through groove 101 is formed on the inner circuit board 10.

[0072] The through groove 101 extends through the first surface 11 and the second surface 12. The through groove 101 can be formed by mechanical drilling or laser drilling.

[0073] Step S3, please refer to Figure 3 A carrier plate 20 is attached to the second surface 12 of the inner circuit board 10 to seal one end of the through groove 101.

[0074] The surface of the carrier plate 20 that contacts the inner circuit board 10 is provided with an adhesive layer for adhering the component to be embedded. In this embodiment, the carrier plate 20 is an adhesive tape, which is adhered to the surface of the inner circuit board 10 and seals one end of the through groove 101.

[0075] For step S4, please refer to [link / reference]. Figure 4 and Figure 5 An insulating plate 31 is provided. The insulating plate 31 includes a plurality of bodies 311 arranged in a matrix. The plurality of bodies 311 are interconnected to form the insulating plate 31.

[0076] The material of the body 311 has the properties of heat resistance to pressing and laser melting. The material of the body 311 may be, but is not limited to, dielectric materials commonly used in the art, such as polyimide, epoxy resin, etc.

[0077] Step S5, please refer to Figure 6 A groove 301 is formed on each body 311, and a first adhesive layer 32 is formed at the bottom of the groove 301.

[0078] The groove 301 extends through one surface of the body 311. The groove 301 can be formed by mechanical drilling or laser drilling.

[0079] The first adhesive layer 32 may be formed on the bottom wall of the groove 301 by means of printing, coating or dispensing. In this embodiment, the first adhesive layer 32 completely covers the bottom wall of the groove 301.

[0080] For step S6, please refer to [link / reference]. Figure 7 At least one electronic component 33 is mounted on the first adhesive layer 32 located in the groove 301.

[0081] The at least one electronic component 33 is placed on and bonded to the first adhesive layer 32 to position the at least one electronic component 33. The at least one electronic component 33 includes at least one of an active component and a passive component. In this embodiment, one active component and two passive components are housed in the groove 301. It is understood that the number of active and passive components housed in the groove 301 can be adjusted according to actual needs.

[0082] For step S7, please refer to [link / reference]. Figure 8 Glue is filled into the groove 301 to form a second adhesive layer 35, thereby obtaining the electronic component module 30.

[0083] The second adhesive layer 35 covers the exposed surface of the electronic component 33 outside the first adhesive layer 32 and is connected to the first adhesive layer 32. The second adhesive layer 35 and the first adhesive layer 32 together encapsulate the electronic component 33, such that the electronic component 33 is embedded in the adhesive layer formed by the second adhesive layer 35 and the first adhesive layer 32.

[0084] The surface of the second adhesive layer 35 exposed outside the groove 301 is flush with the surface of the body 311 where the groove 301 is provided, that is, the second adhesive layer 35 and the body 311 have the same height level without step difference.

[0085] When the glue is filled into the groove 301 to form the second glue layer 35, since the electronic component 33 is fixed in the groove 301 by the first glue layer 32, the risk of the electronic component 33 shifting due to glue flow can be reduced.

[0086] The materials of the first adhesive layer 32 and the second adhesive layer 35 may be, but are not limited to, room temperature curing adhesives.

[0087] Step S8, please refer to Figure 9 Multiple electronic component modules 30 are separated along the boundary lines between the multiple bodies 311. The multiple electronic component modules 30 can be separated by mechanical cutting or laser cutting, etc.

[0088] For step S9, please refer to [link / reference]. Figure 10 The electronic component module 30 is placed in the through groove 101.

[0089] The electronic component module 30 is supported on the carrier plate 20 and is bonded to the carrier plate 20 to position the electronic component module 30.

[0090] In this embodiment, the electronic component module 30 is flipped and placed in the through groove 101, so that the adhesive layer of the electronic component module 30 is bonded to the carrier plate 20, thereby improving the bonding strength between the electronic component module 30 and the carrier plate 20.

[0091] In this embodiment, the height of the electronic component module 30 is equal to the depth of the through groove 101.

[0092] Step S10, please refer to Figure 11 A first base layer 41 is pressed onto the first surface 11 of the inner circuit substrate 10.

[0093] The first base layer 41 covers the first surface 11 of the inner circuit board 10 and the exposed surface of the electronic component module 30, and fills the gap between the electronic component module 30 and the sidewall of the through groove 101.

[0094] The material of the first base layer 41 can be a dielectric material commonly used in the field, such as polyimide, epoxy resin, etc.

[0095] Step S11, please refer to Figure 12 Remove the carrier plate 20 to expose the second surface 12 of the inner circuit board 10.

[0096] The support plate 20 can be removed by tearing or other means.

[0097] Step S12, please refer to Figure 13 A second base layer 51 is pressed onto the second surface 12 of the inner circuit substrate 10.

[0098] The second base layer 51 covers the second surface 12 of the inner circuit board 10 and the surface of the electronic component module 30 exposed outside the first base layer 41, and is connected to the first base layer 41. The first base layer 41 and the second base layer 51 together cover the electronic component module 30, such that the electronic component module 30 is embedded in the base layer formed by the first base layer 41 and the second base layer 51.

[0099] The material of the second base layer 51 can be a dielectric material commonly used in the field, such as polyimide, epoxy resin, etc.

[0100] Step S13, please refer to Figure 14 This forms blind holes 110 that expose the solder terminals of the electronic component 33.

[0101] The position and number of the blind holes 110 can be adapted according to the type and number of the electronic components 33, and this application does not impose any limitations. In this embodiment, a plurality of blind holes 110 are formed corresponding to a plurality of electronic components 33, wherein some blind holes 110 penetrate the second base layer 51 and the second adhesive layer 35, and other blind holes 110 penetrate the first base layer 41, the body 311 and the first adhesive layer 32.

[0102] The blind hole 110 can be formed by mechanical drilling or laser drilling.

[0103] Step S14, please refer to Figure 15 A first metal layer 42 and a second metal layer 52 are formed on the surface of the first base layer 41 opposite to the first surface 11 and the surface of the second base layer 51 opposite to the second surface 12, respectively, and a first conductive structure 112 is formed in the blind hole 110.

[0104] The first metal layer 42 completely covers the surface of the first base layer 41 facing away from the first surface 11 of the inner circuit board 10, and the second metal layer 52 completely covers the surface of the second base layer 51 facing away from the second surface 12 of the inner circuit board 10. The first metal layer 42 and the second metal layer 52 are electrically connected to the solder terminals of the corresponding electronic components 33 through corresponding first conductive structures 112. The first conductive structure 112 can be a conductive hole or a conductive post.

[0105] The first metal layer 42, the second metal layer 52, and the first conductive structure 112 can be formed by electroplating, printing, or other methods. In this embodiment, the first metal layer 42, the second metal layer 52, and the first conductive structure 112 can be formed by electroplating, and the first conductive structure 112 is a conductive hole.

[0106] Step S15, please refer to Figure 16 Circuitry is fabricated on the first metal layer and the second metal layer to form a first conductive circuit layer 43 and a second conductive circuit layer 53, respectively.

[0107] The first conductive line layer 43 and the second conductive line layer 53 can be formed using image transfer and etching processes.

[0108] The first conductive line layer 43 and the first base layer 41 together constitute the first circuit board 40. The second conductive line layer 53 and the second base layer 51 together constitute the second circuit board 50. The first conductive line layer 43 and the second conductive line layer 53 are respectively electrically connected to the corresponding electronic components 33 through corresponding first conductive structures 112.

[0109] Step S16, please refer to Figure 17 A third circuit board 60 and a fourth circuit board 70 are formed on the surfaces of the first conductive line layer 43 and the second conductive line layer 53, respectively, to obtain an embedded circuit board 100.

[0110] The third circuit board 60 includes a third base layer 61 and a third conductive line layer 63 stacked together. The third base layer 61 covers the first conductive line layer 43 and fills the gaps in the lines of the first conductive line layer 43 to connect with the first base layer 41. The third conductive line layer 63 is located on the side of the third base layer 61 opposite to the first conductive line layer 43.

[0111] The fourth circuit board 70 includes a fourth base layer 71 and a fourth conductive line layer 73 stacked together. The fourth base layer 71 covers the second conductive line layer 53 and fills the gaps in the lines of the second conductive line layer 53 to connect with the second base layer 51. The fourth conductive line layer 73 is located on the side of the fourth base layer 71 opposite to the second conductive line layer 53.

[0112] The materials of the third base layer 61 and the fourth base layer 71 can be dielectric materials commonly used in the art, such as polyimide, epoxy resin, etc.

[0113] The embedded circuit board 100 also includes a plurality of second conductive structures 113. Some of the second conductive structures 113 are electrically connected to the first conductive line layer 43 and the third conductive line layer 63, and other second conductive structures 113 are electrically connected to the second conductive line layer 53 and the fourth conductive line layer 73. The second conductive structure 113 can be a conductive via or a conductive post.

[0114] Please see Figure 17 The present application also provides an embedded circuit board 100, including an inner circuit board 10, an electronic component module 30, a first circuit board 40, a second circuit board 50, a third circuit board 60 and a fourth circuit board 70.

[0115] The inner circuit board 10 includes a first surface 11 and a second surface 12 disposed opposite to each other, and a through groove 101 is formed through the first surface 11 and the second surface 12. The electronic component module 30 is housed in the through groove 101. The first circuit board 40 includes a first base layer 41 and a first conductive line layer 43 stacked together. The second circuit board 50 includes a second base layer 51 and a second conductive line layer 53 stacked together. The first base layer 41 covers the first surface 11, the second base layer 51 covers the second surface, and the first base layer 41 and the second base layer 51 fill the through groove 101 to jointly cover the electronic component module 30.

[0116] The electronic component module 30 includes a body 311, at least one electronic component 33, a first adhesive layer 32, and a second adhesive layer 35. The body 311 has a groove 301. The at least one electronic component 33 is fixed to the bottom wall of the groove 301 by the first adhesive layer 32, and the second adhesive layer 35 fills the groove 301 and together with the first adhesive layer 32 covers the at least one electronic component 33.

[0117] In the embedded circuit board 100 and its manufacturing method provided in this application, the electronic component module 30 is pre-bonded and positioned on the carrier plate 20, reducing the risk of displacement caused by dielectric material flow in the subsequent bonding layer process; and the electronic component 33 is pre-fixed in the groove 301 by the first adhesive layer 32, further reducing the risk of displacement caused by adhesive flow in the subsequent filling process. In addition, by integrating multiple electronic components 33 into the electronic component module 30, the process flow can be simplified.

[0118] The above-disclosed embodiments are merely preferred embodiments of this application and should not be construed as limiting the scope of this application. Therefore, any equivalent variations made in accordance with this application are still within the scope of this application.

Claims

1. A method for manufacturing an embedded circuit board, characterized in that, Includes the following steps: An inner circuit board is provided, the inner circuit board including a first surface and a second surface disposed opposite to each other; A through groove is formed on the inner circuit board, the through groove connecting the first surface and the second surface; A support plate is attached to the second surface to seal one end of the through groove; An electronic component module is provided, the electronic component module including a body, at least one electronic component, a first adhesive layer and a second adhesive layer, the body having a groove, the at least one electronic component being fixed to the bottom wall of the groove by the first adhesive layer, and the second adhesive layer filling the groove and together with the first adhesive layer covering the at least one electronic component, the surface of the second adhesive layer exposed outside the groove being flush with the surface of the body having the groove; The electronic component module is placed in the through groove, wherein the electronic component module is bonded to the support plate, and the height of the electronic component module is equal to the depth of the through groove; A first base layer is pressed onto the first surface; Remove the support plate; A second base layer is pressed onto the second surface, wherein the first base layer and the second base layer fill the through groove and together cover the electronic component module; A first conductive line layer is formed on the surface of the first base layer opposite to the first surface to obtain a first circuit substrate, and a second conductive line layer is formed on the surface of the second base layer opposite to the second surface to obtain a second circuit substrate.

2. The method for manufacturing an embedded circuit board as described in claim 1, characterized in that, The steps for "providing an electronic component module" include: A body is provided, and a groove is formed on the body; A first adhesive layer is formed at the bottom of the groove; At least one electronic component is mounted on the first adhesive layer; Glue is filled into the groove to form a second adhesive layer, wherein the second adhesive layer and the first adhesive layer together cover the at least one electronic component.

3. The method for manufacturing an embedded circuit board as described in claim 1, characterized in that, When the electronic component module is placed in the through groove, the second adhesive layer is bonded to the carrier plate.

4. The method for manufacturing an embedded circuit board as described in claim 1, characterized in that, It also includes the following steps: A third circuit board and a fourth circuit board are formed on the surfaces of the first conductive line layer and the second conductive line layer, respectively.

5. The method for manufacturing an embedded circuit board as described in claim 1, characterized in that, The at least one electronic component includes at least one of an active component and a passive component.

6. An embedded circuit board, characterized in that, The system includes an inner circuit board, an electronic component module, a first circuit board, and a second circuit board. The inner circuit board includes a first surface and a second surface disposed opposite to each other and has a through groove passing through the first surface and the second surface. The electronic component module is housed in the through groove, and the height of the electronic component module is equal to the depth of the through groove. The electronic component module includes a body, at least one electronic component, a first adhesive layer, and a second adhesive layer. The body has a groove, and the at least one electronic component is fixed to the bottom wall of the groove by the first adhesive layer. The second adhesive layer fills the groove and, together with the first adhesive layer, covers the at least one electronic component. The surface of the second adhesive layer exposed outside the groove is flush with the surface of the body with the groove. The first circuit board includes a first base layer and a first conductive line layer stacked together. The second circuit board includes a second base layer and a second conductive line layer stacked together. The first base layer covers the first surface, and the second base layer covers the second surface. The first base layer and the second base layer fill the through groove to jointly cover the electronic component module.

7. The embedded circuit board as described in claim 6, characterized in that, The embedded circuit board also includes a third circuit board and a fourth circuit board respectively disposed on the surfaces of the first conductive line layer and the second conductive line layer.

8. The embedded circuit board as described in claim 6, characterized in that, The at least one electronic component includes at least one of an active component and a passive component.

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