Circuit board and manufacturing method thereof

Abstract

A circuit board includes a circuit substrate and solder, wherein the circuit substrate includes a connection pad, and the solder is disposed on the surface of the connection pad. The circuit board also includes a surrounding portion, which is disposed on the surface of the connection pad provided with the solder, and the surrounding portion cooperates with the connection pad to form a groove to accommodate the solder; the surrounding portion is disposed around the solder and is spaced apart from the solder. The present invention also relates to a method for manufacturing a circuit board. In the circuit board and its manufacturing method, the tin block can be precisely disposed on the metal pad, and the solder is spaced apart from the surrounding portion, providing sufficient accommodation space for the solder when it subsequently melts, thereby reducing the risk of the solder overflowing and contacting other circuits.

Description

Technical Field

[0001] The present invention relates to the field of circuit boards, and in particular to a circuit board with solder and a manufacturing method thereof. Background Art

[0002] Due to the rapid development of circuit boards, their applications are becoming more and more widespread. As electronic products develop towards high integration, miniaturization, and micro-miniaturization, the line width and line spacing of circuits on circuit boards are becoming smaller and smaller, making the connection pads connecting the circuit boards to external components smaller and smaller. When connecting external components to the connection pads, solder is usually applied to the surface of the connection pads first, and then the external components are soldered using the solder. However, as the connection pads become smaller and the line spacing becomes smaller, it becomes increasingly difficult to accurately apply the solder, and it is easy for the solder to be misaligned with the connection pads, poor contact, and solder to overflow onto other circuits. Summary of the Invention

[0003] In view of this, the present invention provides a circuit board that solves the above technical problems.

[0004] Also provided is a method for manufacturing a circuit board that solves the above technical problem.

[0005] A circuit board includes a circuit substrate and solder, the circuit substrate includes a connection pad, the solder is arranged on the surface of the connection pad, the circuit board also includes a surrounding portion, the surrounding portion is arranged on the surface of the connection pad provided with the solder, and the surrounding portion cooperates with the connection pad to form a groove to accommodate the solder; the surrounding portion is arranged around the solder and is spaced apart from the solder.

[0006] A method for manufacturing a circuit board, comprising the following steps:

[0007] Laminating and pressing a resin layer and a composite substrate along a first direction;

[0008] Embedding solder and a surrounding portion on a side of the resin layer away from the composite substrate, wherein the solder and the surrounding portion respectively penetrate at least the resin layer, and the surrounding portion is disposed around the solder and spaced apart from the solder;

[0009] A circuit substrate is formed on one side of the composite board where the solder and the surrounding portion are embedded, wherein the circuit substrate includes a connection pad, the connection pad is arranged corresponding to the surrounding portion and the solder, and seals one side of the surrounding portion to cooperate with the surrounding portion to form a groove, and the solder is located in the groove; and

[0010] The composite substrate is removed, and the portion of the resin layer located in the groove is removed.

[0011] In the circuit board and its manufacturing method of the present application, the solder can be precisely placed in the groove, which helps to improve the stability of the connection between the solder and the connection pad. At the same time, the spacing between the solder and the surrounding portion provides sufficient space for the solder when it subsequently melts, reducing the risk of the solder overflowing and contacting other circuits. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figures 1 to 9 A schematic cross-sectional view of a circuit board manufacturing process according to an embodiment of the present application.

[0013] Description of main component symbols

[0014]

[0015]

[0016] The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments.

[0018] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application.

[0019] The following describes some embodiments of the present application in detail with reference to the accompanying drawings. In the absence of conflict, the following embodiments and features of the embodiments may be combined or replaced with each other.

[0020] See also Figures 1 to 8 In one embodiment of the present application, a method for manufacturing a circuit board 100 is provided, which includes the following steps:

[0021] Step S21, please refer to Figure 1 , providing a composite substrate 10, wherein the composite substrate 10 includes a carrier plate 11 and a peelable film 13 stacked along a first direction X.

[0022] The material of the carrier plate 11 may include but is not limited to at least one of metal, hard resin, glass, etc. For example, the carrier plate 11 may be a metal plate or a glass plate.

[0023] Step S22, see Figure 2A resin layer 15 is laminated on the side of the peelable film 13 facing away from the carrier plate 11 , and a first opening 161 is formed along the first direction X, penetrating the resin layer 15 and the peelable film 13 . Part of the carrier plate 11 is exposed from the first opening 161 .

[0024] Step S23, please refer to Figure 3 , fill the first opening 161 with solder 20 .

[0025] Preferably, the solder 20 can fill the first opening 161 , and the surface of the solder 20 facing away from the carrier board 11 can be flush with the surface of the resin layer 15 facing away from the carrier board 11 .

[0026] The solder 20 may be, but is not limited to, tin paste, copper paste, etc.

[0027] Step S24, please refer to Figure 4 A second opening 163 is opened around the solder 20 along the first direction X and passes through the resin layer 15, the second opening 163 is spaced from the solder 20, and metal is plated in the second opening 163 to form a surrounding portion 17 arranged around the solder 20, wherein the surrounding portion 17 is spaced from the solder 20.

[0028] Preferably, a second opening 163 surrounding the solder 20 may be opened with the center of the solder 20 as the center point.

[0029] Step S25, please refer to Figure 5 and Figure 6 A circuit substrate 30 is formed on the side of the resin layer 15 facing away from the carrier board 11. The circuit substrate 30 includes a first circuit layer 31 bonded to the surface of the resin layer 15 facing away from the carrier board 11. The first circuit layer 31 includes connection pads 313 corresponding to the surrounding portion 17 and the solder 20. The connection pads 313 seal one side of the surrounding portion 17 to form a groove 301 with the surrounding portion 17. The solder 20 is located in the groove 301.

[0030] The first circuit layer 31 may further include at least one signal line 311 spaced apart from the connection pad 313 .

[0031] The circuit substrate 30 can be a single-layer circuit board, a double-layer circuit board or a multi-layer circuit board. Figure 6, the circuit substrate 30 is described as a double-layer circuit board. Specifically, the circuit substrate 30 may further include a dielectric layer 33 and a second circuit layer 35. The second circuit layer 35 is stacked and spaced apart from the first circuit layer 31 along the first direction X. The second circuit layer 35 is electrically connected to the first circuit layer 31, with the dielectric layer 33 interposed therebetween.

[0032] Step S26, see Figure 7 , peeling off the composite substrate 10 and removing the portion of the resin layer 15 located in the groove 301 .

[0033] The height of the solder 20 exceeds the depth of the groove 301 , thereby facilitating electrical connection with an external electronic component (not shown).

[0034] The portion of the resin layer 15 located in the groove 301 may be removed by, but not limited to, laser ablation followed by plasma removal of smear.

[0035] Step S27, please refer to Figure 8 , the remaining portion of the resin layer 15 outside the groove 301 is removed, thereby manufacturing the circuit board 100.

[0036] In some embodiments, the above step S27 may be omitted, and the resin layer 15 may serve as a protective layer of the circuit board 100 a to protect the first circuit layer 31 , thereby eliminating the need for an additional solder mask layer.

[0037] In some embodiments, before step S25 , the method for manufacturing the circuit board may further include roughening the surface of the solder 20 facing away from the carrier board 11 to increase the bonding force between the connection pad 313 and the solder 20 when the connection pad 313 is subsequently formed.

[0038] In some embodiments, the circuit substrate 30 can be manufactured by, but not limited to, the following methods:

[0039] Step S251, please refer to Figure 9 A first dielectric layer 331 is laminated on the surface of the resin layer 15 facing away from the carrier board 11, and the first dielectric layer 331 is patterned. The patterned first dielectric layer 331 includes third openings 332 corresponding to the surrounding portion 17 and the solder 20. The surrounding portion 17 and the solder 20 are exposed through the third openings 332.

[0040] The patterned first dielectric layer 331 may further include a circuit opening 334 spaced apart from the third opening 332 .

[0041] Step S252, please refer to Figure 5 The first dielectric layer 331 is patterned to form a first circuit layer 31 embedded in the first dielectric layer 331 , wherein the first circuit layer 31 includes a connection pad 313 embedded in the third opening 332 .

[0042] The first circuit layer 31 may further include a signal line 311 embedded in the circuit opening 334 .

[0043] Step S253, please refer to Figure 6 A second dielectric layer 335 is laminated onto the first circuit layer 31 and the patterned first dielectric layer 331 on a side facing away from the carrier board 11, and a second circuit layer 35 is disposed on a side of the second dielectric layer 335 facing away from the carrier board 11. The second circuit layer 35 is electrically connected to the first circuit layer 31. The first dielectric layer 331 and the second dielectric layer 335 constitute the dielectric layer 33.

[0044] In this embodiment, the second circuit layer 35 may be electrically connected to the connection pad 313 through a conductive via 36 .

[0045] In some embodiments, the depth of the first opening 161 may be less than or equal to the depth of the second opening 163. The formation of the solder 20 and the surrounding portion 17 are not limited to the above methods. However, in the present application, it is preferred that the depth of the first opening 161 is greater than the depth of the second opening 163.

[0046] See also Figure 8 A circuit board 100a according to one embodiment of the present application includes a circuit substrate 30, a surrounding portion 17, and solder 20. The circuit substrate 30 includes a first circuit layer 31. The first circuit layer 31 includes a connection pad 313. The solder 20 and the surrounding portion 17 are disposed on the surface of the connection pad 313. The surrounding portion 17 cooperates with the connection pad 313 to form a groove 301 for accommodating the solder 20. The surrounding portion 17 surrounds the solder 20 and is spaced apart from the solder 20.

[0047] In some embodiments, the height of the solder 20 may be preferably greater than the depth of the groove 301 , thereby facilitating subsequent electrical connection with external electronic components. In some embodiments, the height of the solder 20 may also be less than or equal to the depth of the groove 301 .

[0048] The surface of the solder 20 facing the connection pad 313 may be roughened, thereby facilitating improvement of the bonding strength between the solder 20 and the connection pad 313 .

[0049] In some embodiments, see Figure 7The circuit board 100 may further include a resin layer 17 , which is disposed on a side of the circuit substrate 30 where the solder 20 is disposed, and covers an area of ​​the first circuit layer 31 except the connection pad 313 .

[0050] The side of the resin layer 17 facing away from the first circuit layer 31 may be flush with the side of the surrounding portion 17 facing away from the first circuit layer 31 .

[0051] The circuit substrate 30 can be a single-layer circuit board, a double-layer circuit board, or a multi-layer circuit board. In this embodiment, a double-layer circuit board is used as an example. The circuit substrate 30 further includes a dielectric layer 33 and a second circuit layer 35. The first circuit layer 31 is embedded in the dielectric layer 33 from one side of the dielectric layer 33. The second circuit layer 35 is disposed on the side of the dielectric layer 33 facing away from the first circuit layer 31, and the second circuit layer 35 is electrically connected to the first circuit layer 31.

[0052] In some embodiments, the second circuit layer 15 may be electrically connected to the connection pad 313 through a conductive via 36 .

[0053] In the circuit board and its manufacturing method of the present application, the solder 20 can be precisely placed in the groove 301, which helps to improve the stability of the connection between the solder 20 and the connection pad 313. At the same time, the spacing between the solder 20 and the surrounding portion 17 provides sufficient space for the solder 20 when it is subsequently melted, reducing the risk of the solder 20 overflowing and contacting other circuits.

[0054] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any technician familiar with this profession can make some changes or modifications to equivalent embodiments of the technical content disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for manufacturing a circuit board, comprising the following steps: Laminating and pressing a resin layer and a composite substrate along a first direction; Embedding solder and a surrounding portion on a side of the resin layer away from the composite substrate, wherein the solder and the surrounding portion respectively penetrate at least the resin layer, and the surrounding portion is disposed around the solder and spaced apart from the solder; forming a circuit substrate on one side of the composite substrate in which the solder and the surrounding portion are embedded, wherein the circuit substrate includes a connection pad, the connection pad being arranged corresponding to the surrounding portion and the solder and sealing one side of the surrounding portion to cooperate with the surrounding portion to form a groove, the solder being located in the groove; and The composite substrate is removed, and the portion of the resin layer located in the groove is removed.

2. The method for manufacturing a circuit board according to claim 1, wherein: The composite substrate includes a carrier plate and a peelable film stacked along the first direction, and the resin layer is combined with a side of the peelable film facing away from the carrier plate.

3. The method for manufacturing a circuit board according to claim 2, wherein: The step of "embedding solder and a surrounding portion from a side of the resin layer facing away from the composite substrate, wherein the solder and the surrounding portion respectively penetrate at least the resin layer, and the surrounding portion is disposed around the solder and spaced apart from the solder" specifically includes: A first opening is opened along the first direction and passes through the resin layer and the peelable film, wherein a portion of the carrier plate is exposed from the first opening; filling solder into the first opening; and A second opening is opened around the solder along the first direction and penetrates the resin layer, the second opening is spaced from the solder, and metal is plated in the second opening to form a surrounding portion surrounding the solder, wherein the surrounding portion is spaced from the solder.

4. The method for manufacturing a circuit board according to claim 1 or 3, wherein: The method for manufacturing a circuit board further includes, after the step of "removing the composite substrate and removing the portion of the resin layer located in the groove": The remaining portion of the resin layer outside the groove is removed.

5. The method for manufacturing a circuit board according to claim 1, wherein: Before forming the circuit substrate, the method for manufacturing the circuit board further includes: A surface of the solder facing away from the composite substrate is roughened.

6. The method for manufacturing a circuit board according to claim 3, wherein: “Opening a second opening around the solder and penetrating the resin layer along the first direction” specifically means: A second opening is opened around the solder with the center of the solder as the center point.

7. The method for manufacturing a circuit board according to claim 1, wherein: The circuit substrate is a single-layer circuit board, a double-layer circuit board or a multi-layer circuit board.

8. A circuit board, characterized in that: The circuit board is manufactured by the circuit board manufacturing method according to any one of claims 1 to 7, the circuit board includes a circuit substrate and solder, the circuit substrate includes a connection pad, the solder is arranged on the surface of the connection pad, the circuit board also includes a surrounding portion, the surrounding portion is arranged on the surface of the connection pad where the solder is provided, and the surrounding portion cooperates with the connection pad to form a groove to accommodate the solder; the surrounding portion is arranged around the solder and is spaced apart from the solder.

9. The circuit board according to claim 8, wherein: The height of the solder is greater than the depth of the groove.

10. The circuit board according to claim 8, wherein The circuit board further includes a resin layer, which covers an area on a side of the circuit substrate where the solder is provided except for the connection pad.

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