CN115226304A - Circuit board and method for manufacturing the same - Google Patents

Circuit board and method for manufacturing the same Download PDF

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Publication number
CN115226304A
CN115226304A CN202110426798.6A CN202110426798A CN115226304A CN 115226304 A CN115226304 A CN 115226304A CN 202110426798 A CN202110426798 A CN 202110426798A CN 115226304 A CN115226304 A CN 115226304A
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CN
China
Prior art keywords
layer
circuit
circuit board
groove
metal layer
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Pending
Application number
CN202110426798.6A
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Chinese (zh)
Inventor
李卫祥
王浩
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Avary Holding Shenzhen Co Ltd
Qing Ding Precision Electronics Huaian Co Ltd
Original Assignee
Avary Holding Shenzhen Co Ltd
Qing Ding Precision Electronics Huaian Co Ltd
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Application filed by Avary Holding Shenzhen Co Ltd, Qing Ding Precision Electronics Huaian Co Ltd filed Critical Avary Holding Shenzhen Co Ltd
Priority to CN202110426798.6A priority Critical patent/CN115226304A/en
Publication of CN115226304A publication Critical patent/CN115226304A/en
Pending legal-status Critical Current

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    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K3/00—Apparatus or processes for manufacturing printed circuits
    • H05K3/0011—Working of insulating substrates or insulating layers
    • H05K3/0017—Etching of the substrate by chemical or physical means
    • H05K3/0026—Etching of the substrate by chemical or physical means by laser ablation
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K1/00—Printed circuits
    • H05K1/02—Details
    • H05K1/0277—Bendability or stretchability details
    • H05K1/0283—Stretchable printed circuits
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K3/00—Apparatus or processes for manufacturing printed circuits
    • H05K3/40—Forming printed elements for providing electric connections to or between printed circuits
    • H05K3/4007—Surface contacts, e.g. bumps
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K3/00—Apparatus or processes for manufacturing printed circuits
    • H05K3/40—Forming printed elements for providing electric connections to or between printed circuits
    • H05K3/4038—Through-connections; Vertical interconnect access [VIA] connections

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  • Engineering & Computer Science (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Manufacturing & Machinery (AREA)
  • Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Printing Elements For Providing Electric Connections Between Printed Circuits (AREA)

Abstract

A method of manufacturing a circuit board, the method comprising the steps of: providing a copper-clad plate, wherein the copper-clad plate comprises a base layer, a first metal layer and a second metal layer; forming a groove penetrating through the first metal layer and the base layer by laser drilling; filling the groove with conductive paste, forming a conductive column by the conductive paste in the groove, and forming a bonding pad by the conductive paste protruding out of the surface of the first metal layer; forming through holes penetrating through the bonding pads, the conductive columns and the second metal layer through laser drilling; and respectively manufacturing the first metal layer and the second metal layer into a first circuit layer and a second circuit layer, wherein the first circuit layer and the second circuit layer both comprise welding areas, and the welding pads are arranged on the first circuit layer positioned on the welding areas to obtain the circuit board. The manufacturing method of the circuit board provided by the invention can ensure the smoothness of the bonding pad and also ensure the good flexibility of the circuit board. In addition, the invention also provides a circuit board.

Description

Circuit board and method for manufacturing the same
Technical Field
The present invention relates to printed circuit board technology, and more particularly, to a printed circuit board and a method for manufacturing the same.
Background
The two circuit boards are connected by a traditional method of reflow soldering. However, the reflow soldering method needs to heat the whole circuit board, and generally the reflow soldering temperature is high, which is likely to damage some parts or electronic components that are not high temperature resistant or sensitive to heat; also, signal transmission loss of the circuit board may increase.
At present, two circuit boards are mostly connected by laser welding. In order to ensure that the surface of the circuit board is smooth and beneficial to laser welding, the circuit board needs to be plated with copper on the whole surface, namely, the copper is plated at other positions besides a bonding pad formed by plating copper on the surface of the through hole. However, plating copper over the entire surface can affect the flexibility of the circuit. If the circuit is well bent, copper is only selected and plated on the surface of the through hole, but the copper selection and plating cannot ensure the surface smoothness of the circuit board.
Disclosure of Invention
In view of the above, in order to solve at least one of the above-mentioned drawbacks, it is necessary to provide a method for manufacturing a circuit board.
In addition, the invention also provides a circuit board manufactured by the manufacturing method.
The invention provides a manufacturing method of a circuit board, which comprises the following steps:
the copper-clad plate comprises a base layer, and a first metal layer and a second metal layer which are arranged on two opposite surfaces of the base layer.
The first metal layer and the second metal layer are respectively manufactured into a first circuit layer and a second circuit layer, the first circuit layer and the second circuit layer both comprise welding areas, and first groove portions are formed in the first circuit layer positioned on the welding areas.
And forming a second groove part in the base layer in a laser drilling mode, wherein the first groove part and the second groove part form a groove together.
And filling conductive paste in the groove, wherein the conductive paste is also protruded out of the surface of the first circuit layer in the welding area, the conductive paste in the groove forms a conductive column, and the conductive paste protruded out of the surface of the first circuit layer forms a welding pad.
And forming a through hole penetrating through the welding pad, the conductive column and the second circuit layer in a laser drilling mode to obtain the circuit board.
In an embodiment of the present application, along an extending direction of the circuit board, a size of the second groove portion is larger than a size of the through hole and smaller than or equal to a size of the first groove portion.
In an embodiment of the present application, after forming the through hole, the method further includes:
in an embodiment of the present application, the second groove portion further penetrates through the second circuit layer.
The invention also provides a manufacturing method of the circuit board, which comprises the following steps:
the copper-clad plate comprises a base layer, a first metal layer and a second metal layer, wherein the first metal layer and the second metal layer are arranged on two opposite surfaces of the base layer.
And forming a groove penetrating through the first metal layer and the base layer in a laser drilling mode.
And filling a conductive paste in the groove, wherein the conductive paste also protrudes out of the surface of the first metal layer, the conductive paste in the groove forms a conductive column, and the conductive paste protruding out of the surface of the first metal layer forms a bonding pad.
And forming through holes penetrating through the bonding pads, the conductive columns and the second metal layer in a laser drilling mode.
And respectively manufacturing the first metal layer and the second metal layer into a first circuit layer and a second circuit layer, wherein the first circuit layer and the second circuit layer both comprise welding areas, and the welding pads are arranged on the first circuit layer positioned on the welding areas to obtain the circuit board.
In the embodiment of the application, along the extending direction of the circuit board, the size of the groove is larger than that of the through hole.
In an embodiment of the present application, after the first circuit layer and the second circuit layer are manufactured, the method further includes:
in this embodiment, the groove further penetrates through the second circuit layer.
The invention also provides a circuit board, which comprises a base layer, a first circuit layer, a second circuit layer groove, a conductive column, a welding disc and a through hole, wherein the first circuit layer is arranged on one surface of the base layer, the second circuit layer is arranged on the other surface of the base layer far away from the first circuit layer, the first circuit layer and the second circuit layer both comprise welding areas, and the first circuit layer and the base layer positioned on the welding areas are provided with grooves; the conductive posts are arranged in the grooves; the bonding pad protrudes out of the surface of the first circuit layer of the welding area and is electrically connected with the conductive column; the through hole penetrates through the welding disc, the conductive column and the second circuit layer.
In the embodiment of the application, along the extending direction of the circuit board, the size of the groove is larger than that of the through hole.
In the embodiment of the present application, the circuit board further includes a surface treatment layer disposed on an inner wall of the through hole, and the surface treatment layer further covers the pad and the first and second circuit layers located in the pad.
In the embodiment of the present application, the groove further penetrates through the second circuit layer.
Compared with the prior art, the manufacturing method of the circuit board provided by the invention has the advantages that the groove is formed firstly through a laser hole forming method, the groove is filled with the conductive paste, the conductive paste protrudes out of the surface of the first circuit layer to form the bonding pad, and the bonding pad is used for laser welding between subsequent circuit boards. In the process of forming the bonding pad by the conductive paste, the flatness of the bonding pad and the thickness difference between the bonding pad and the peripheral circuit layer are easy to control, so that the subsequent laser welding between circuit boards is facilitated. And then, forming a through hole on the conductive paste in a laser hole forming mode, and further curing the conductive paste at high temperature in the laser forming process of the through hole to ensure that the conductive paste has no fluidity, so that the hardness of the conductive paste can be improved by further irreversible curing, and the surface smoothness of the bonding pad cannot be influenced in the laser forming process of the through hole. In addition, laser welding between the circuit boards is realized by adopting a mode of locally forming the welding pads and the through holes on the circuit boards, the whole circuit board does not need to be electroplated, and good flexibility and flexibility of the circuit board can be ensured.
Drawings
Fig. 1 is a schematic diagram of a copper-clad plate according to an embodiment of the present invention.
Fig. 2 is a schematic diagram of a protective film attached to the copper-clad plate shown in fig. 1.
Fig. 3 is a schematic view of forming an opening on the protective film shown in fig. 2.
Fig. 4 is a schematic diagram of forming a third groove on the copper-clad plate shown in fig. 3.
Fig. 5 is a schematic view of filling the third groove shown in fig. 4 with a conductive paste.
Fig. 6 is a schematic view of forming a via hole in the conductive paste shown in fig. 5.
Fig. 7 is a schematic diagram of forming a circuit layer from the metal layer shown in fig. 6.
Fig. 8 is a schematic view of forming a surface treatment layer in the through-hole shown in fig. 7.
Fig. 9 is a schematic structural diagram of a circuit formed on the copper-clad plate shown in fig. 1.
Fig. 10 is a schematic diagram of a protective film attached on the first circuit layer shown in fig. 9.
Fig. 11 is a schematic view of forming a second groove on the base layer shown in fig. 10.
Fig. 12 is a schematic view of filling the conductive paste in the first and second grooves shown in fig. 11.
Fig. 13 is a schematic view of the formation of a via in the conductive paste of fig. 12.
Fig. 14 is a schematic view of forming a surface treatment layer in the through-hole shown in fig. 13.
Fig. 15 is a schematic structural diagram of a circuit board according to still another embodiment of the present invention.
Fig. 16 is a schematic structural diagram of a circuit board according to a fourth embodiment of the present invention.
Description of the main elements
Circuit boards 100, 200, 300, 400
Copper-clad plate 10
Base layer 11
First metal layer 12
Second metal layer 13
First circuit layers 14, 16
Second wiring layers 15, 17
First groove part 18
Second groove portions 19, 20
Protective film 2
Opening 21
Grooves 3, 5
Conductive paste 4
Conductive post 41
Bonding pad 42
Through-hole 6
Surface treatment layer 7
Solder mask layer 8
Weld zone A
Non-welded area B
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.
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.
An embodiment of the present invention provides a method for manufacturing a circuit board 100, which specifically includes the following steps:
step S11, please refer to fig. 1, providing a copper-clad plate 10, where the copper-clad plate 10 includes a base layer 11, and a first metal layer 12 and a second metal layer 13 disposed on two opposite surfaces of the base layer 11.
In the present embodiment, the base layer 11 is made of an insulating resin, and specifically, the base layer 11 may be made of one selected from epoxy resin (epoxy resin), prepreg (PP), BT resin, polyphenylene Oxide (PPO), polyimide (PI), polyethylene Terephthalate (PET), polyethylene Naphthalate (PEN), and the like.
In step S12, referring to fig. 2, a protective film 2 is covered on the first metal layer 12.
In the present embodiment, the protective film 2 may be a PET film.
In step S13, referring to fig. 3, an opening 21 is formed on the protection film 2, and a portion of the first metal layer 12 is exposed from the opening 21.
In this embodiment, the dimension a of the opening 21 along the extending direction of the copper-clad plate 10 can be set according to the dimension of the required bonding pad.
In the present embodiment, the opening 21 is formed by CO 2 Laser ablation method.
Step S14, referring to fig. 4, a groove 3 is formed in the opening 21 along the thickness direction of the copper-clad plate 10 by laser drilling, and the groove 3 penetrates through the first metal layer 12 and the base layer 11. The recess 3 does not extend through the second metal layer 13. Along the extending direction of the copper-clad plate 10, the size b of the groove 3 is smaller than the size a of the opening 21.
In the present embodiment, after the formation of the open groove 3, the opening 21 and the groove 3 are also treated by plasma (plasma) to remove CO 2 Carbide remains on the surface of the openings 21 and the grooves 3 after laser ablation and laser drilling.
In this embodiment, the groove 3 may be circular, square or other shapes.
In step S15, referring to fig. 5, the groove 3 and the opening 21 are filled with a conductive paste 4. The conductive paste 4 disposed in the recess 3 forms a conductive pillar 41, and a portion of the conductive paste 4 disposed in the opening 21 forms a pad 42.
In the present embodiment, the pad 42 fills the opening 21.
In this embodiment, the conductive paste 4 may be, but not limited to, a copper paste.
In this embodiment, after the conductive paste 4 is filled, the method further includes curing the conductive paste 4.
In step S16, referring to fig. 6, the protective film 2 is removed, and a through hole 6 penetrating through the bonding pad 42, the conductive pillar 41, and the second metal layer 13 is opened by laser drilling.
Form through-hole 6 on electrically conductive cream 4 through the mode of laser beam drilling, the heat that produces in the laser beam drilling process can further solidify electrically conductive cream 4 simultaneously, can provide electrically conductive cream 4's chemical stability and guarantee electric connection's stability, and simultaneously, the metal level that forms after electrically conductive cream 4 solidifies is attached to the inner wall at through-hole 6 more firmly, the firm in connection nature when improving follow-up laser welding.
In this embodiment, along the extending direction of the copper-clad plate 10, the size c of the through hole 6 is smaller than the size b of the groove 3. The opening 21 is filled with the conductive paste 4 to form the bonding pad 42, so that the flatness of the surface of the bonding pad 42 can be ensured, and the subsequent laser welding is facilitated. In addition, the solder pads 42 are bonded to the small-diameter through holes 6 for subsequent laser welding, thereby ensuring good flexibility of the circuit board 100.
Step S17, referring to fig. 7, a circuit is formed on the first metal layer 12 and the second metal layer 13, specifically, a first circuit layer 14 and a second circuit layer 15 are respectively formed through processes of film pressing, exposure, development, etching, film removal, and the like, the first circuit layer 14 and the second circuit layer 15 both include a welding area a and a non-welding area B except the welding area a, and the bonding pad 42 is disposed on the welding area a.
Step S18, referring to fig. 8, forming solder masks 8 on the first circuit layer 14 and the second circuit layer 15 on the non-bonding area B, and forming a surface treatment layer 7 on the inner wall of the through hole 6, where the surface treatment layer 7 further covers the bonding pad 42 and the first circuit layer 14 and the second circuit layer 15 in the bonding area a, so as to obtain the circuit board 100.
In this embodiment, the surface treatment layer 7 includes, but is not limited to, a electroless nickel plating layer or an electroless gold plating layer. Through surface treatment, the inner wall of the through hole 6, the surface of the bonding pad 42 and the first circuit layer 14 and the second circuit layer 15 in the welding area A are covered by the surface treatment layer 7, so that the chemical stability of the bonding pad 42 and the conductive column 41 is improved, the stability of electrical connection is ensured, the stability of combination between the bonding pad 42 and the first circuit layer 14 and the second circuit layer 15 is enhanced, and the connection strength of subsequent laser welding is further improved.
Referring to fig. 15, in another embodiment, the groove 5 may further penetrate through the second metal layer 13, which is shown in fig. 15, and the groove 5 penetrates through the second circuit layer 15. The groove 5 penetrates through the base layer 11 and the second metal layer 13, the manufacturing process is relatively simple, meanwhile, the adhesion area of the subsequent conductive paste 4 in the groove 5 can be increased, the adhesion force is increased, the firmness degree of the conductive column 41 and the bonding pad 42 is enhanced, and therefore the connection strength during subsequent laser welding is improved.
Referring to fig. 1, 9 to 14, a method for manufacturing a circuit board 200 according to another embodiment of the present invention is different from the method for manufacturing a circuit board 200 according to the first embodiment in that the steps of forming the first circuit layer 16 and the second circuit layer 17 are different. In this embodiment, the method specifically includes the steps of:
step S21, please refer to fig. 1 again, providing a copper-clad plate 10, where the copper-clad plate 10 includes a base layer 11, and a first metal layer 12 and a second metal layer 13 disposed on two opposite surfaces of the base layer 11.
In the present embodiment, the base layer 11 is made of an insulating resin, and specifically, the base layer 11 may be made of one selected from epoxy resin (epoxy resin), prepreg (PP), BT resin, polyphenylene Oxide (PPO), polyimide (PI), polyethylene Terephthalate (PET), polyethylene Naphthalate (PEN), and the like.
In step S22, referring to fig. 9, the first metal layer 12 and the second metal layer 13 are etched to form a first circuit layer 14 and a second circuit layer 15, respectively. The first wiring layer 16 and the second wiring layer 17 each include a land a and a non-land B other than the land a, and the first wiring layer 16 located in the land a is provided with a first groove portion 18.
In the present embodiment, the first circuit layer 16 and the second circuit layer 17 are fabricated by processes such as film pressing, exposure, development, etching, and film removal.
In step S23, referring to fig. 10, a protective film 2 is covered on the surface of the first circuit layer 16.
In the present embodiment, the protective film 2 may be a PET film.
Step S24, please refer to fig. 11, an opening 21 is formed on the protective film 2, and the first groove portion 18 and a portion of the first circuit layer 16 are exposed from the opening 21.
In this embodiment, along the extending direction of the copper-clad plate 10, the size a of the opening 21 can be set according to the size of the required bonding pad.
In this embodiment, the opening 21 is through CO 2 Laser ablation method.
Referring to fig. 11 again, in step S25, a second groove portion 19 communicated with the first groove portion 18 is opened in the base layer 11 from the opening 21 in a laser drilling manner, and the first groove portion 18 is communicated with the second groove portion 19 to form a groove 3.
In this embodiment, along the extending direction of the copper-clad plate 10, the dimension e of the second groove portion 19 is smaller than or equal to the dimension d of the first groove portion 18.
In the present embodiment, after the second groove portion 19 is formed, the opening 21 and the groove 3 are also treated by plasma (plasma) to remove CO 2 After laser ablation and laser drillingCarbide remains on the surfaces of the openings 21 and the grooves 3.
In this embodiment, the second groove 19 may be circular, square or other shapes.
In step S26, referring to fig. 12, the groove 3 and the opening 21 are filled with the conductive paste 4. A conductive pillar 41 is formed on a portion of the conductive paste 4 disposed in the recess 3, and a pad 42 is formed on a portion of the conductive paste 4 disposed in the opening 21.
In the present embodiment, the pad 42 fills the opening 21.
In this embodiment, the conductive paste 4 may be, but not limited to, a copper paste.
In this embodiment, after the conductive paste 4 is filled, the method further includes curing the conductive paste 4.
In step S27, referring to fig. 13, the protective film 2 is removed, and a through hole 6 penetrating through the pad 42, the conductive post 41 and the second circuit layer 17 is opened by laser drilling.
Form through-hole 6 on electrically conductive cream 4 through the mode of laser beam drilling, the heat that produces in the laser beam drilling process can further solidify electrically conductive cream 4 simultaneously, can provide electrically conductive cream 4's chemical stability and guarantee electric connection's stability, and simultaneously, the metal level that forms after electrically conductive cream 4 solidifies is attached to the inner wall at through-hole 6 more firmly, the firm in connection nature when improving follow-up laser welding.
In this embodiment, along the extending direction of the copper-clad plate 10, the size c of the through hole 6 is smaller than the size e of the second groove portion 19. The second groove portion 19 and the first groove portion 18 are filled with the conductive paste 4 to form a conductive column 41, and the opening 21 is filled with the conductive paste 4 to form a bonding pad 42, so that flatness of the bonding pad 42 can be guaranteed, and subsequent laser welding is facilitated. In addition, the solder pads 42 are bonded to the small-diameter through holes 6 for subsequent laser welding, thereby ensuring good flexibility of the circuit board 200.
Step S28, referring to fig. 14, forming solder masks 8 on the first circuit layer 16 and the second circuit layer 17 on the non-bonding area B, and forming a surface treatment layer 7 on the inner wall of the through hole 6, wherein the surface treatment layer 7 further covers the bonding pad 42 and the first circuit layer 16 and the second circuit layer 17 in the bonding area a, so as to obtain the circuit board 200.
In the present embodiment, the surface treatment layer 7 includes, but is not limited to, a electroless nickel plating layer or an electroless gold plating layer. Through surface treatment, the inner wall of the through hole 6, the surface of the bonding pad 42 and the first circuit layer 16 and the second circuit layer 17 in the welding area A are covered by the surface treatment layer 7, so that the chemical stability of the bonding pad 42 and the conductive column 41 is improved, the stability of electric connection is ensured, the stability of combination between the bonding pad 42 and the first circuit layer 16 and the second circuit layer 17 is enhanced, and the connection strength of subsequent laser welding is further improved.
According to the two circuit board preparation methods of the invention, the bonding pad 42 and the through hole 6 can be formed before the circuit is manufactured, and the bonding pad 42 and the through hole 6 can also be formed after the circuit is manufactured. Therefore, the preparation method of the circuit board has wide application range, is not limited by specific manufacturing procedures, and can form the bonding pad 42 and the through hole 6 before and after the circuit layer is formed so as to meet the requirement of subsequent laser welding connection with other circuit boards.
Referring to fig. 8, the present invention further provides a circuit board 100 manufactured by using the manufacturing method of the circuit board 100, where the circuit board 100 includes a base layer 11, a first circuit layer 14, a second circuit layer 15, a groove 3, a conductive pillar 41, a pad 42, and a through hole 6, the first circuit layer 14 and the second circuit layer 15 are disposed on two opposite surfaces of the base layer 11, each of the first circuit layer 14 and the second circuit layer 15 includes a welding area a, and the groove 3 is formed on the first circuit layer 14 and the base layer 11 located on the welding area a; the conductive posts 41 are arranged in the grooves 3; the bonding pad 42 protrudes from the surface of the first circuit layer 14 at the bonding pad a, and is electrically connected to the conductive pillar 41; the through hole 6 is disposed through the pad 42, the conductive pillar 41, and the second circuit layer 15.
In the present embodiment, the dimension b of the groove 3 is larger than the dimension c of the through hole 6 along the extending direction of the circuit board 100. The size of the groove 3 is larger to fill the conductive paste 4 to form the conductive post 41 and the pad 42, which meets the requirement of the subsequent laser welding, so the size of the groove 3 is larger. In addition, by forming the through hole 6, electrical conduction can be formed. The groove 3 on the circuit board 100 is filled with the conductive paste 4 to form the conductive column 41, and further protrudes out of the first circuit layer 14 to form the pad 42, and in the process of forming the pad 42 by using the conductive paste, the flatness of the pad 42 and the thickness difference between the pad 42 and the surrounding circuit layer are easy to control, so that the flatness of the pad 42 can be ensured, and the subsequent laser welding is facilitated. In addition, the conductive paste 4 is combined with the small-diameter through hole 6 to perform local laser welding connection of the circuit board, and good flexibility of the circuit board 100 can be ensured.
In this embodiment, the circuit board 100 further includes a non-soldering area other than the soldering area a, the first circuit layer 14 and the second circuit layer 15 on the non-soldering area B are provided with solder masks 8, the inner wall of the through hole 6 is provided with a surface treatment layer 7, and the surface treatment layer 7 further covers the soldering pad 42 and the first circuit layer 14 and the second circuit layer 15 in the soldering area a.
In the present embodiment, the surface treatment layer 7 includes, but is not limited to, a electroless nickel plating layer or an electroless gold plating layer. Through surface treatment, the surface treatment layer 7 can be added on the inner wall of the through hole 6 and the surface of the bonding pad 42, so that the chemical stability of the bonding pad 42 and the conductive column 41 is improved, the stability of electrical connection is ensured, and meanwhile, the connection strength of subsequent laser welding can be improved.
In the present embodiment, the base layer 11 is made of an insulating resin, and specifically, the base layer 11 may be made of one selected from epoxy resin (epoxy resin), prepreg (PP), BT resin, polyphenylene Oxide (PPO), polyimide (PI), polyethylene Terephthalate (PET), polyethylene Naphthalate (PEN), and the like.
Referring to fig. 15, another embodiment of the invention further provides a circuit board 300. The difference from the circuit board 100 is that the groove 5 penetrates through the base layer 11 and the second circuit layer 15, meanwhile, the conductive paste 4 is attached to the inner wall of the groove 5 to form a conductive column 41, and the through hole 6 penetrates through the pad 42 and the conductive column 41, so as to obtain the circuit board 300. Through running through basic unit 11 and second circuit layer 15 and forming recess 5, the processing procedure is simple relatively, simultaneously, can improve the adhesion area of follow-up conductive paste 4 in recess 5, improves adhesive force, strengthens leading the firm degree of electrical pillar 41 and pad 42 to joint strength when improving follow-up laser welding.
Referring to fig. 14, the present invention further provides a circuit board 200 manufactured by the method for manufacturing the circuit board 200, wherein the circuit board 200 includes: the circuit board comprises a base layer 11, a first circuit layer 16, a second circuit layer 17, a groove 3, a conductive column 41, a pad 42 and a through hole 6, wherein the first circuit layer 16 and the second circuit layer 17 are arranged on two opposite surfaces of the base layer 11; the first circuit layer 16 and the second circuit layer 17 both include a welding area a, a first groove portion 18 is formed on the first circuit layer 16 located at the welding area a, a second groove portion 19 is formed on the base layer 11 located at the welding area a, and the first groove portion 18 and the second groove portion 19 are communicated and form the groove 3 together; the conductive posts 41 are arranged in the grooves 3; the bonding pad 42 protrudes from the surface of the first circuit layer 16 at the bonding pad a, and is electrically connected to the conductive pillar 41; the through hole 6 is disposed through the pad 42, the conductive pillar 41, and the second circuit layer 17.
In the present embodiment, the dimension e of the second groove portion 19 is smaller than or equal to the dimension d of the first groove portion 18 in the extending direction of the circuit board 200. When the first groove portion 18 and the second groove portion 19 have the same size, the structure of the circuit board 100 is the same. The size of the first groove portion 18 is larger than that of the second groove portion 19, and the first groove portion and the second groove portion form a stepped groove 3, and the stepped groove 3 is beneficial to improving the adhesion stability of the conductive paste 4. In the process of forming the bonding pad 42 by the conductive paste 4, the flatness of the bonding pad 42 and the thickness difference between the bonding pad 42 and the surrounding circuit layer are easy to control, so that the flatness of the bonding pad 42 can be ensured, and the subsequent laser welding is facilitated. In addition, the conductive paste 4 is combined with the small-diameter through hole 6 to perform local laser welding connection of the circuit board, and good flexibility of the circuit board 200 can be ensured.
In this embodiment, the circuit board 200 further includes a non-soldering area other than the soldering area a, the first circuit layer 16 and the second circuit layer 17 on the non-soldering area B are provided with solder masks 8, the inner wall of the through hole 6 is provided with a surface treatment layer 7, and the surface treatment layer 7 further covers the soldering pad 42 and the first circuit layer 16 and the second circuit layer 17 in the soldering area a.
In the present embodiment, the surface treatment layer 7 includes, but is not limited to, a electroless nickel plating layer or an electroless gold plating layer. Through surface treatment, the surface treatment layer 7 can be added on the inner wall of the through hole 6 and the surface of the bonding pad 42, so that the chemical stability of the bonding pad 42 and the conductive column 41 is improved, the stability of electric connection is ensured, and the connection strength of subsequent laser welding can be improved.
In the present embodiment, the material of the base layer 11 is an insulating resin, and specifically, the material of the base layer 11 may be one selected from epoxy resin (epoxy resin), prepreg (PP), BT resin, polyphenylene Oxide (PPO), polyimide (PI), polyethylene Terephthalate (PET), polyethylene Naphthalate (PEN), and the like.
Referring to fig. 16, another embodiment of the invention further provides a circuit board 400. The difference from the circuit board 200 is that the second groove portion 20 is disposed through the base layer 11 and the second circuit layer 17, and at the same time, the conductive paste 4 is attached to the inner wall of the second groove portion 20 to form a conductive column 41, and the through hole 6 penetrates through the pad 42 and the conductive column 41, so that the circuit board 400 is obtained. By penetrating through the base layer 11 and the second circuit layer 17 to form the second groove portion 20, the manufacturing process is relatively simple, and meanwhile, the adhesion area of the subsequent conductive column 41 in the second groove portion 20 can be increased, the adhesion force is increased, the firmness of the conductive column 41 and the bonding pad 42 is enhanced, and therefore the connection strength during subsequent laser welding is increased.
In summary, in the manufacturing method of the circuit board provided by the invention, the groove (referred to as the second groove or the third groove) is formed first by a laser hole-forming method, the groove is filled with the conductive paste, the conductive paste protrudes out of the surface of the first circuit layer to form the bonding pad, and the bonding pad is used for laser welding between subsequent circuit boards. In the process of forming the bonding pad by the conductive paste, the flatness of the bonding pad and the thickness difference between the bonding pad and the surrounding circuit layer are easy to control, and the subsequent laser welding between circuit boards is facilitated. And then, a through hole is formed on the conductive paste in a laser hole forming mode, and the conductive paste is further cured at high temperature in the laser forming process of the through hole, so that the conductive paste does not have fluidity. In addition, laser welding between the circuit boards is realized by adopting a mode of locally forming the welding pads and the through holes of the circuit boards, the whole circuit board does not need to be electroplated, and the good flexibility of the circuit board can be ensured.

Claims (10)

1. A method of manufacturing a circuit board, comprising the steps of:
providing a copper-clad plate, which comprises a base layer, a first metal layer and a second metal layer, wherein the first metal layer and the second metal layer are arranged on two opposite surfaces of the base layer;
respectively manufacturing the first metal layer and the second metal layer into a first circuit layer and a second circuit layer, wherein the first circuit layer and the second circuit layer both comprise a welding area, and the first circuit layer positioned on the welding area is provided with a first groove part;
forming a second groove part communicated with the first groove part in the base layer in a laser drilling mode, wherein the first groove part and the second groove part jointly form a groove;
filling a conductive paste in the groove, wherein the conductive paste also protrudes out of the surface of the first circuit layer of the welding area, the conductive paste in the groove forms a conductive column, and the conductive paste protruding out of the surface of the first circuit layer forms a welding pad; and
and forming a through hole penetrating through the welding pad, the conductive column and the second circuit layer in a laser drilling mode to obtain the circuit board.
2. The method for manufacturing a circuit board according to claim 1, wherein a size of the second groove portion is larger than a size of the through hole and smaller than or equal to a size of the first groove portion in an extending direction of the circuit board.
3. The method for manufacturing a circuit board according to claim 1, wherein the second groove portion further penetrates the second wiring layer.
4. A method of manufacturing a circuit board, comprising the steps of:
providing a copper-clad plate, which comprises a base layer, a first metal layer and a second metal layer, wherein the first metal layer and the second metal layer are arranged on two opposite surfaces of the base layer;
forming a groove penetrating through the first metal layer and the base layer in a laser drilling mode;
filling a conductive paste in the groove, wherein the conductive paste also protrudes out of the surface of the first metal layer, the conductive paste in the groove forms a conductive column, and the conductive paste protruding out of the surface of the first metal layer forms a bonding pad;
forming a through hole penetrating through the bonding pad, the conductive post and the second metal layer in a laser drilling mode; and
and respectively manufacturing the first metal layer and the second metal layer into a first circuit layer and a second circuit layer, wherein the first circuit layer and the second circuit layer both comprise welding areas, and the welding pads are arranged on the first circuit layer positioned on the welding areas to obtain the circuit board.
5. The method for manufacturing a circuit board according to claim 4, wherein a size of the groove is larger than a size of the through hole in an extending direction of the circuit board.
6. The method for manufacturing a circuit board according to claim 4, wherein the groove further penetrates the second metal layer.
7. A circuit board, comprising:
a base layer;
the first circuit layer is arranged on one surface of the base layer;
the second circuit layer is arranged on the other surface of the base layer, which is far away from the first circuit layer, the first circuit layer and the second circuit layer both comprise welding areas, and grooves are formed in the first circuit layer and the base layer which are positioned in the welding areas;
the conductive column is positioned in the groove;
the bonding pad protrudes out of the surface of the first circuit layer of the welding area and is electrically connected with the conductive column; and
and the through hole penetrates through the welding pad, the conductive column and the second circuit layer.
8. The circuit board of claim 7, wherein a dimension of the recess is larger than a dimension of the through hole in an extending direction of the circuit board.
9. The circuit board of claim 7, further comprising a surface treatment layer disposed on an inner wall of the via, the surface treatment layer further covering the pad and the first and second wiring layers within the land.
10. The circuit board of claim 7, wherein the recess is further disposed through the second circuit layer.
CN202110426798.6A 2021-04-20 2021-04-20 Circuit board and method for manufacturing the same Pending CN115226304A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202110426798.6A CN115226304A (en) 2021-04-20 2021-04-20 Circuit board and method for manufacturing the same

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202110426798.6A CN115226304A (en) 2021-04-20 2021-04-20 Circuit board and method for manufacturing the same

Publications (1)

Publication Number Publication Date
CN115226304A true CN115226304A (en) 2022-10-21

Family

ID=83605702

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202110426798.6A Pending CN115226304A (en) 2021-04-20 2021-04-20 Circuit board and method for manufacturing the same

Country Status (1)

Country Link
CN (1) CN115226304A (en)

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