Circuit board with embedded electronic components and method of manufacturing the same
By using localized heating to solder electronic components to the connecting pads and filling the gaps with dielectric layers, the problem of exposed inner layer circuitry on circuit boards with embedded electronic components is solved, thus improving reliability.
Patent Information
- Application Number
- CN202111211916.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2021-10-18
- Publication Date
- 2025-11-28
- Estimated Expiration
- 2041-10-18
AI Technical Summary
Existing circuit boards with embedded electronic components have the problem of exposed inner layer circuitry, leading to reliability risks.
Electronic components are pressed into the second dielectric layer by local heating and soldered to the tin layer on the internal connection pad. The thermal fluidity of the second dielectric layer is used to increase the filling of the gap between the electronic components and the connection pad, forming an embedded structure.
This improves the reliability of the circuit board and avoids reliability risks caused by exposed internal structures.
Smart Images
Figure CN115996526B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the field of circuit board, in particular to a circuit board with embedded electronic components and a manufacturing method thereof. BACKGROUND
[0002] With the increasing demand for size and light and thin appearance of application products, especially in the demand for supporting portable and mobile applications, highly integrated assembly, thinner packaging becomes more and more critical. As the main connecting component in electronic products, flexible circuit board occupies a large space of electronic products. The compact and thin packaging between flexible substrate and electronic components is conducive to the development trend of light, thin, short and small electronic products.
[0003] However, the existing circuit board with embedded electronic components often has the problem of exposed inner layer circuit, which easily leads to reliability risk. SUMMARY
[0004] Therefore, the present application provides a circuit board with embedded electronic components and a manufacturing method thereof, which is beneficial to improve the reliability of the product.
[0005] As one of the schemes of the present application, the manufacturing method of the circuit board with embedded electronic components comprises the following steps:
[0006] A first circuit substrate is provided, which comprises a first metal foil, a first dielectric layer and a first circuit layer arranged in sequence, and the first circuit layer comprises a plurality of connection pads;
[0007] A gold layer is formed on the surface of the plurality of connection pads away from the first metal foil, and a tin layer is formed on the gold layer;
[0008] The first circuit substrate provided with the tin layer, an adhesive layer and a single-sided metal substrate are laminated and pressed in sequence to obtain a first intermediate structure; the adhesive layer is bonded to the first circuit layer and is provided with a first opening corresponding to the plurality of connection pads, and the single-sided metal substrate comprises a thermoplastic second dielectric layer bonded to the adhesive layer and a second metal foil arranged on the side of the second dielectric layer away from the adhesive layer;
[0009] The first intermediate structure is subjected to circuit manufacturing to form a second circuit layer corresponding to the first metal foil, a third circuit layer corresponding to the second metal foil, and the third circuit layer is provided with a window corresponding to the first opening to expose the second dielectric layer;
[0010] A plurality of second openings are formed in the second dielectric layer, each of the second openings penetrates the second dielectric layer along the stacking direction and corresponds to one of the connection pads, so that the first intermediate structure after circuit manufacturing corresponds to a second intermediate structure;
[0011] An electronic component provided with a plurality of solder pads is pressed into the pre-heated second intermediate structure from the second dielectric layer by a heating head, wherein each of the solder pads corresponds to one of the connection pads and is soldered through the second dielectric layer and the tin layer on the corresponding connection pad to electrically connect, and the second dielectric layer increases in fluidity after being heated to fill the first openings and fill the gaps between the electronic component and the connection pads.
[0012] As an aspect of the present application, a manufacturing method of a circuit board with embedded electronic components includes the following steps:
[0013] A first circuit substrate is provided, which includes a first metal foil, a first dielectric layer and a first circuit layer arranged in sequence, and the first circuit layer includes a plurality of connection pads;
[0014] A gold layer is formed on the surface of the connection pads away from the first metal foil, and a tin layer is formed on the gold layer;
[0015] The first circuit substrate provided with the tin layer, an adhesive layer and a single-sided metal substrate are laminated and pressed in sequence to obtain a first intermediate structure; the adhesive layer is bonded to the first circuit layer and provided with first openings corresponding to the plurality of connection pads, and the single-sided metal substrate includes a thermoplastic second dielectric layer bonded to the adhesive layer and a second metal foil arranged on the side of the second dielectric layer away from the adhesive layer;
[0016] Circuit manufacturing is performed on the first intermediate structure to form a second circuit layer corresponding to the first metal foil, a third circuit layer corresponding to the second metal foil, and the third circuit layer is provided with an opening corresponding to the first opening to expose the second dielectric layer;
[0017] The area of the second dielectric layer corresponding to the first opening is thinned to form a second intermediate structure corresponding to the first intermediate structure after circuit manufacturing;
[0018] An electronic component provided with a plurality of solder pads is pressed into the pre-heated second intermediate structure from the second dielectric layer by a heating head, wherein each of the solder pads corresponds to one of the connection pads and is soldered through the second dielectric layer and the tin layer on the corresponding connection pad to electrically connect, and the second dielectric layer increases in fluidity after being heated to fill the first openings and fill the gaps between the electronic component and the connection pads.
[0019] As one aspect of this application, a circuit board with embedded electronic components includes a circuit board and electronic components. The circuit board includes a first outer circuit layer, an inner circuit layer, and a second outer circuit layer stacked sequentially and spaced apart along the thickness direction. The inner circuit layer includes a plurality of connection pads, and each connection pad has a gold plating layer and a tin layer sequentially disposed on the surface opposite to the first outer circuit layer. The first outer circuit layer and the inner circuit layer are bonded together by a first dielectric layer. An adhesive layer is disposed between the inner circuit layer and the second outer circuit layer, and the adhesive layer has an opening corresponding to the plurality of connection pads. The electronic components are disposed corresponding to the opening and soldered to the tin layer via solder pads. A second dielectric layer is further disposed between the adhesive layer and the second outer circuit layer, and the second dielectric layer fills the opening and fills the gap between the electronic components and the connection pads.
[0020] The circuit board with embedded electronic components and its manufacturing method disclosed in this application presses the electronic components into the second dielectric layer by local heating to solder them to the tin layer on the internal connection pad. At the same time, the second dielectric layer becomes more fluid when heated to fill the space between the electronic components and the connection pad, thereby avoiding the risk of reliability issues caused by the exposure of the inner layer structure of the circuit board. Attached Figure Description
[0021] Figure 1 This is a cross-sectional schematic diagram of a first circuit board according to an embodiment of this application.
[0022] Figure 2 In order to be in Figure 1 The diagram shows a cross-sectional view of the first circuit substrate having a gold plating layer and a tin layer.
[0023] Figure 3 This is a cross-sectional schematic diagram of the first intermediate structure according to an embodiment of this application.
[0024] Figure 4 for Figure 3 The diagram shows a cross-sectional view of the first intermediate structure after circuit fabrication.
[0025] Figure 5 This is a cross-sectional schematic diagram of the second intermediate structure according to an embodiment of this application.
[0026] Figure 6 To press electronic components through the heating head towards Figure 5 The diagram shows a cross-sectional view of the second intermediate structure.
[0027] Figure 7 for Figure 6 The diagram shows a cross-sectional view of the electronic component after it has been pressed together with the second intermediate structure.
[0028] Figure 8A cross-sectional view of a second intermediate structure according to another embodiment of the present application.
[0029] Figure 9 A cross-sectional view of a circuit board with embedded electronic components according to an embodiment of the present application.
[0030] Explanation of main element symbols
[0031] First circuit substrate 10
[0032] First metal foil 11
[0033] First dielectric layer 13
[0034] First circuit layer 15
[0035] Connection pad 151
[0036] Plating layer 21
[0037] Tin layer 23
[0038] Adhesion layer 30
[0039] Single-sided metal substrate 40
[0040] First intermediate structure 50
[0041] Second dielectric layer 41
[0042] Second metal foil 43
[0043] First opening, opening 31
[0044] Second circuit layer 110
[0045] Third circuit layer 430
[0046] Window 431
[0047] Second opening 410
[0048] Second intermediate structure 53
[0049] Solder pan 61
[0050] Electronic component 60
[0051] Heating head 70
[0052] Circuit board with embedded electronic components 100
[0053] Circuit substrate 100a
[0054] First outer circuit layer 101
[0055] Inner circuit layer 102
[0056] the second outer layer circuit layer 103
[0057] The following detailed description will further describe the present application in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION
[0058] The technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all of the embodiments of the present application.
[0059] Unless otherwise defined, 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 application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.
[0060] Some embodiments of the present application will be described in detail in conjunction with the drawings. The following embodiments and features in the embodiments can be combined with each other without conflict.
[0061] Referring to Figures 1 to 7 An embodiment of the present application provides a manufacturing method of a circuit board with embedded electronic components, which comprises the following steps:
[0062] Step S1, referring to Figure 1 A first circuit substrate 10 is provided, which comprises a first metal foil 11, a first dielectric layer 13 and a first circuit layer 15 which are sequentially stacked. The first circuit layer 15 comprises a plurality of connection pads 151.
[0063] In some embodiments, the first circuit substrate 10 can further comprise at least one inner layer circuit layer (not shown in the figure), which is located between the first metal foil 11 and the first circuit layer 15 and is spaced apart from the first metal foil 11 and the first circuit layer 15 in the stacking direction, respectively.
[0064] In the present embodiment, the first circuit layer 15 can be electrically connected with the first metal foil 11. The inner layer circuit layer can also be electrically connected with the first metal foil 11 and / or the first circuit layer 15.
[0065] Step S2, referring to Figure 2 A gold layer 21 is formed on the surface of the plurality of connection pads 151 away from the first metal foil 11, and a tin layer 23 is formed on the gold layer 21.
[0066] The tin layer 23 can be formed by, but not limited to, brushing tin, spraying tin and the like.
[0067] Step S3, referring toFigure 3 The first circuit substrate 10 provided with the tin layer 23, an adhesive layer 30, and a single-sided metal substrate 40 are sequentially laminated and compressed to obtain a first intermediate structure 50. The adhesive layer 30 is adhered to the first circuit layer 15 and provided with first openings 31 corresponding to the connection pads 151. The single-sided metal substrate 40 includes a second dielectric layer 41 adhered to the adhesive layer 30 and a second metal foil 43 provided on the side of the second dielectric layer 41 away from the adhesive layer 30.
[0068] The second dielectric layer 41 is made of a thermoplastic resin, which can include but is not limited to at least one of liquid crystal polymer (LCP), acrylonitrile-butadiene-styrene copolymer (ABS), polypropylene (PP), polytetrafluoroethylene (PTFE), polyether ether ketone (PEEK), and polyphenylene oxide (PPO).
[0069] Step S4, referring to Figure 3 and Figure 4 The first intermediate structure 50 is subjected to circuit fabrication to form a second circuit layer 110 corresponding to the first metal foil 11, a third circuit layer 430 corresponding to the second metal foil 43, and a window 431 provided in the third circuit layer 430 corresponding to the first openings 31 to expose the second dielectric layer 41.
[0070] Preferably, in any direction perpendicular to the lamination direction, the width of the window 431 is greater than the width of the first opening 31.
[0071] Step S5, referring to Figure 5 A plurality of second openings 410 are formed in the second dielectric layer 41, each of which penetrates the second dielectric layer 41 along the lamination direction and corresponds to a connection pad 151, so that the first intermediate structure 50 after circuit fabrication corresponds to a second intermediate structure 53.
[0072] Each of the second openings 410 can have a cross-section perpendicular to the lamination direction in the form of but not limited to a regular shape such as a circle, a square, a diamond, a hexagon, or any irregular shape.
[0073] Each of the second openings 410 can be formed by but not limited to laser cutting, mechanical cutting, or etching.
[0074] Step S6, referring to Figure 6 and Figure 7, providing an electronic component 60 with a plurality of solder pads 61, and pressing the electronic component 60 into the pre-heated second intermediate structure 53 from the side of the second dielectric layer 41 away from the first dielectric layer 13 by a heating head 70, wherein each of the solder pads 61 corresponds to a connection pad 151 and is soldered to the tin layer 23 on the corresponding connection pad 151 through the second dielectric layer 41 to be electrically connected, and the second dielectric layer 41 flows to fill the first opening 31 and the gap between the electronic component 60 and the connection pad 151 after being heated.
[0075] The electronic component 60 can be partially embedded in the second intermediate structure 53, or completely embedded in the second intermediate structure 53.
[0076] In some embodiments, step S5 can be replaced by step S5'. Specifically, step S5' is as follows: Figure 8 Thinning the region of the second dielectric layer 41 corresponding to the first opening 31.
[0077] The thinning of the second dielectric layer 41 can be formed by, but not limited to, laser cutting, mechanical cutting, or etching, etc.
[0078] Please refer to Figure 9 The circuit board 100 with an embedded electronic component according to an embodiment of the present application includes a circuit substrate 100a and an electronic component 60. The circuit substrate 100a includes a first outer layer circuit layer 101, an inner layer circuit layer 102, and a second outer layer circuit layer 103 which are sequentially stacked in the thickness direction with intervals. The inner layer circuit layer 102 includes a plurality of connection pads 151, and each of the connection pads 151 is provided with a gold layer 21 and a tin layer 23 in sequence on the surface away from the first outer layer circuit layer 101. The first outer layer circuit layer 101 and the inner layer circuit layer 102 are combined by a first dielectric layer 13. A bonding layer 30 is provided between the inner layer circuit layer 102 and the second outer layer circuit layer 103, and the bonding layer 30 has an opening 31 to correspond to a plurality of the connection pads 151. The electronic component 60 is arranged corresponding to the opening 31 and is soldered to the tin layer 23 by a solder pad 61. A second dielectric layer 41 is further provided between the bonding layer 30 and the second outer layer circuit layer 103, and the second dielectric layer 41 fills the opening 31 and fills the gap between the electronic component 60 and the connection pad 151.
[0079] The material of the second dielectric layer 41 is thermoplastic resin, which can include, but not limited to, at least one of liquid crystal polymer (LCP), acrylonitrile-butadiene-styrene copolymer (ABF), polypropylene (PP), polytetrafluoroethylene (PTFE), polyether ether ketone (PEEK), and polyphenylene oxide (PPO).
[0080] The electronic component 60 can be partially embedded or completely embedded in the circuit substrate 100a.
[0081] The inner layer circuit layer 102 can be electrically connected to the first outer layer circuit layer 101 and the second outer layer circuit layer 103, respectively.
[0082] The circuit substrate 100a can further include other inner layer circuit layers (not shown) between the first outer layer circuit layer 101 and the second outer layer circuit layer 103.
[0083] The circuit board with embedded electronic components and the manufacturing method thereof of the present application press the electronic component 60 into the second dielectric layer 41 by local heating to weld the tin layer 23 on the connecting pad 151, and the second dielectric layer 41 increases in flowability under heat to fill the space between the electronic component 60 and the connecting pad 151, thereby avoiding the reliability risk caused by the exposure of the inner layer structure of the circuit board.
[0084] The above description is only the preferred embodiments of the present application, and is not intended to limit the present application in any form. Although the preferred embodiments of the present application have been disclosed as above, the present application is not intended to be limited thereto. Any person skilled in the art can make some changes or modifications to the above disclosed technical contents without departing from the technical solution of the present application, and any simple modification, equivalent change and modification made according to the technical essence of the present application to the above embodiments shall still fall within the scope of the technical solution of the present application.
Claims
1. A method for manufacturing a circuit board with embedded electronic components, comprising the steps of: providing a first circuit substrate including a first metal foil, a first dielectric layer, and a first circuit layer stacked in sequence, the first circuit layer including a plurality of connection pads; forming a gold layer on surfaces of the plurality of connection pads facing away from the first metal foil, and forming a tin layer on the gold layer; laminating the first circuit substrate with the tin layer, an adhesive layer, and a single-sided metal substrate in sequence to obtain a first intermediate structure, the adhesive layer being bonded to the first circuit layer and having first openings corresponding to the plurality of connection pads, the single-sided metal substrate including a thermoplastic second dielectric layer bonded to the adhesive layer, and a second metal foil disposed on a side of the second dielectric layer facing away from the adhesive layer; performing circuit fabrication on the first intermediate structure to form a second circuit layer corresponding to the first metal foil, a third circuit layer corresponding to the second metal foil, and the third circuit layer having openings corresponding to the first openings to expose the second dielectric layer; forming a plurality of second openings in the second dielectric layer, each of the second openings penetrating the second dielectric layer along a stacking direction and corresponding to one of the connection pads, so that the first intermediate structure after the circuit fabrication corresponds to a second intermediate structure; providing an electronic component having a plurality of solder pads, and pressing the electronic component into the preheated second intermediate structure through a heating head, wherein each of the solder pads corresponds to one of the connection pads and is soldered to the tin layer on the corresponding connection pad through the second dielectric layer to electrically connect, and the second dielectric layer flows to fill the first openings and gaps between the electronic component and the connection pads after being heated. In any direction perpendicular to the stacking direction, a width of the openings is greater than a width of the first openings. The second dielectric layer is made of at least one of liquid crystal polymer, acrylonitrile-butadiene-styrene copolymer, polypropylene, polytetrafluoroethylene, polyether ether ketone, and polyphenylene oxide. The electronic component is partially or completely embedded in the second intermediate structure. 5.A method for manufacturing a circuit board with embedded electronic components, comprising the steps of: providing a first circuit substrate including a first metal foil, a first dielectric layer, and a first circuit layer stacked in sequence, the first circuit layer including a plurality of connection pads; forming a gold layer on surfaces of the plurality of connection pads facing away from the first metal foil, and forming a tin layer on the gold layer; laminating the first circuit substrate with the tin layer, an adhesive layer, and a single-sided metal substrate in sequence to obtain a first intermediate structure, the adhesive layer being bonded to the first circuit layer and having first openings corresponding to the plurality of connection pads, the single-sided metal substrate including a thermoplastic second dielectric layer bonded to the adhesive layer, and a second metal foil disposed on a side of the second dielectric layer facing away from the adhesive layer; 2. The method of manufacturing a circuit board with embedded electronic components as recited in claim 1, wherein, 3. The method of manufacturing a circuit board with embedded electronic components as recited in claim 1, wherein, 4. The method of manufacturing a circuit board with embedded electronic components as recited in claim 1, wherein, The first intermediate structure is subjected to circuit fabrication, so that the first metal foil corresponds to form a second circuit layer, the second metal foil corresponds to form a third circuit layer, and the third circuit layer is provided with an opening corresponding to the first opening to expose the second dielectric layer; The region of the second dielectric layer corresponding to the first opening is thinned, so that the first intermediate structure after circuit fabrication corresponds to form a second intermediate structure; An electronic component provided with a plurality of solder pads is provided, and the electronic component is pressed into the preheated second intermediate structure from the second dielectric layer by a heating head, wherein each solder pad corresponds to a connection pad and is welded with the tin layer on the corresponding connection pad through the second dielectric layer to be electrically connected, and the second dielectric layer has increased fluidity after being heated to fill the first opening and fill the gap between the electronic component and the connection pad.
6. The method of manufacturing a circuit board with embedded electronic components as recited in claim 5, wherein, In any direction perpendicular to the stacking direction, the width of the opening is greater than the width of the first opening.
7. The method of manufacturing a circuit board with embedded electronic components as recited in claim 5, wherein, The material of the second dielectric layer includes at least one of liquid crystal polymer material, acrylonitrile-butadiene-styrene copolymer, polypropylene, polytetrafluoroethylene, polyether ether ketone and polyphenylene oxide.
8. The method of manufacturing a circuit board with embedded electronic components as recited in claim 5, wherein, The electronic component is partially or completely embedded in the second intermediate structure.
Citation Information
Patent Citations
Printed wiring board with built-in component and its manufacturing method
US20120080221A1