TWI819313B - Circuit board and method for manufacturing the same - Google Patents

Abstract

A circuit board includes a wiring board which includes a substrate layer, a first conductive wiring layer, a second conductive wiring layer, a first conductor layer, a first insulation layer, and a second conductor layer. The first and second conductive wiring layers are disposed on opposite surfaces of the substrate layer. The wiring board defines a first groove penetrating through the substrate layer and the first conductive wiring layer. The second conductive wiring layer is exposed from the first groove. The first conductor is disposed in the first groove and is connected to the first and second conductive wiring layers. The first conductor layer defines a second groove, the first insulation layer is disposed in the second groove and defines a third groove. The second conductor layer is disposed in the third groove. A method for manufacturing the circuit board is further disclosed.

Description

Circuit board and method of making the same

The present application relates to the field of circuit electronics technology, and in particular to a circuit board and a manufacturing method thereof.

In order to meet the development needs of high integration and miniaturization of electronic products, circuit boards are also developing towards the trend of thinning, lightness and miniaturization. One existing solution is to design multi-layer circuit boards. However, as the conductor layers are added, the thickness of the circuit board increases.

In view of this, it is necessary to provide a circuit board and a manufacturing method thereof that can solve the above technical problems.

This application provides a circuit board, including a circuit substrate. The circuit substrate includes a base material layer, a first conductive circuit layer, a second conductive circuit layer, a first conductor layer, a first insulating layer and a second conductor layer. The first conductive circuit layer and the second conductive circuit layer are provided on two opposite surfaces of the base material layer, and the circuit substrate is provided with a first conductive circuit layer penetrating the base material layer and the first conductive circuit layer. Groove, the second conductive circuit layer is exposed from the first groove, the first conductor layer is disposed in the first groove and connected with the first conductive circuit layer and the second conductive circuit The layers are connected, the first conductor layer is provided with a second groove, the first insulating layer is provided in the second groove and has a third groove, the second conductor layer is provided in the in the third groove.

This application also provides a method for manufacturing a circuit board, which includes the following steps: A double-sided copper clad laminate is provided, the double-sided copper clad laminate comprising a base material layer and a first copper foil layer and a second copper foil layer disposed on two opposite surfaces of the base material layer; A first groove is formed on the double-sided cover plate. The first groove penetrates the base material layer and the first copper foil layer, and part of the second copper foil layer is exposed from the first groove; Fill the first groove with a first conductive material, and remove part of the first conductive material to form a second groove to obtain a first conductor layer; Fill the second groove with a first insulating material, and remove part of the first insulating material to form a third groove to obtain a first insulating layer; Fill the third groove with a second conductive material, and remove part of the second conductive material to form a fourth groove to obtain a second conductor layer; Fill the fourth groove with a second insulating material, and remove part of the second insulating material to form a fifth groove to obtain a second insulating layer; Fill the fifth groove with a third conductive material to obtain a third conductor layer; Conduct circuit fabrication on the first copper foil layer and the second copper foil layer to form a first conductive circuit layer and a second conductive circuit layer to obtain a circuit substrate.

The circuit board and its manufacturing method of the present application, by opening a first groove on the double-sided circuit substrate and arranging a plurality of conductor layers in the first groove, make the double-sided circuit substrate have the effect of a multi-layer circuit substrate and reduce the cost of the circuit board. The thickness of the circuit board is conducive to thinning.

The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

It should be noted that, unless otherwise defined, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the technical field belonging to the present invention. The terminology used in the embodiments of the present invention is for the purpose of describing particular embodiments only and is not intended to limit the present invention.

An embodiment of the present application provides a method for manufacturing a circuit board, which includes the following steps.

In step S1, please refer to Figure 1 to provide a double-sided copper clad board 10. The double-sided copper-clad laminate 10 includes a base material layer 11 and a first copper foil layer 13 and a second copper foil layer 14 disposed on two opposite surfaces of the base material layer 11 .

In some embodiments, the material of the base material layer 11 is selected from the group consisting of polyimide (PI), polyethylene terephthalate (PET), and polyethylene naphthalate. At least one of polyethylene naphthalate (PEN) and polyethylene (PE).

In step S2, please refer to FIG. 2 to form a first groove 101 on the double-sided copper clad board 10. The first groove 101 penetrates the base material layer 11 and the first copper foil layer 13 , and part of the second copper foil layer 14 is exposed from the first groove 101 . In this embodiment, a portion of the first copper foil layer 13 and a portion of the base material layer 11 are removed by laser cutting to form the first groove 101 . In other embodiments, part of the first copper foil layer 13 and part of the base material layer 11 may also be removed through other methods.

In some embodiments, the cross-sectional shape of the first groove 101 is U-shaped.

Step S3, please refer to FIG. 3 , filling the first groove 101 with the first conductive material 20 . The first conductive material 20 completely fills the first groove 101 . In this embodiment, the first conductive material 20 is filled into the first groove 101 by printing. In other embodiments, the first conductive material 20 can be filled in the first groove 101 in other ways.

In step S4, please refer to FIG. 4, part of the first conductive material 20 is removed to form the second groove 21, so as to obtain the first conductor layer 22. The removed portion of the first conductive material 20 serves as the first conductor layer 22 , and the space where the removed portion of the first conductive material 20 resides serves as the second groove 21 . In this embodiment, part of the first conductive material 20 is removed by laser cutting. In other embodiments, other methods may be used to remove part of the first conductive material 20 .

In some embodiments, the cross-sectional shape of the second groove 21 is U-shaped, that is, the cross-sectional shape of the first conductor layer 22 is U-shaped.

Step S5 , please refer to FIG. 5 , filling the first insulating material 30 in the second groove 21 . The first insulating material 30 fills the second groove 21 . In this embodiment, the first insulating material 30 is filled into the second groove 21 by printing.

In step S6 , please refer to FIG. 6 , part of the first insulating material 30 is removed to form a third groove 31 to obtain the first insulating layer 32 . The removed portion of the first insulating material 30 serves as the first insulating layer 32 , and the space where the removed portion of the first insulating material 30 is located serves as the third groove 31 . In this embodiment, part of the first insulating material 30 is removed by laser cutting.

In some embodiments, the cross-sectional shape of the third groove 31 is U-shaped, that is, the cross-sectional shape of the first insulating layer 32 is U-shaped.

Step S7, please refer to FIG. 7, filling the third groove 31 with the second conductive material 40. The second conductive material 40 fills the third groove 31 . In this embodiment, the second conductive material 40 is filled into the third groove 31 by printing.

In step S8 , please refer to FIG. 8 , part of the second conductive material 40 is removed to form a fourth groove 41 to obtain a second conductor layer 42 . The removed portion of the second conductive material 40 serves as the second conductor layer 42 , and the space where the removed portion of the second conductive material 40 is located serves as the fourth groove 41 . In this embodiment, part of the second conductive material 40 is removed by laser cutting.

In some embodiments, the cross-sectional shape of the fourth groove 41 is U-shaped, that is, the cross-sectional shape of the second conductor layer 42 is U-shaped.

In step S9 , please refer to FIG. 9 , filling the fourth groove 41 with the second insulating material 50 . The second insulating material 50 fills the fourth groove 41 . In this embodiment, the second insulating material 50 is filled into the fourth groove 41 by printing.

In step S10 , please refer to FIG. 10 , part of the second insulating material 50 is removed to form a fifth groove 51 to obtain a second insulating layer 52 . The removed portion of the second insulating material 50 serves as the second insulating layer 52 , and the space where the removed portion of the second insulating material 50 is located serves as the fifth groove 51 . In this embodiment, part of the second insulating material 50 is removed by laser cutting.

In some embodiments, the cross-sectional shape of the fifth groove 51 is U-shaped, that is, the cross-sectional shape of the second insulating layer 52 is U-shaped.

In step S11 , please refer to FIG. 11 , filling the fifth groove 51 with a third conductive material to obtain a third conductor layer 60 . After the third conductive material filled in the fifth groove 51 is solidified, the third conductor layer 60 is formed. In this embodiment, the third conductive material is filled into the fifth groove 51 by printing.

The third conductor layer 60 is located approximately in the center of the first groove 101 . The third conductor layer 60 has a substantially rectangular cross-sectional shape. The two side walls of the first conductor layer 22 are connected to the first copper foil layer 13 respectively, and the bottom wall of the first conductor layer 22 is connected to the second copper foil layer 14 .

The first conductor layer 22 has an exposed surface 221 exposed outside the double-sided copper clad laminate 10 , the first insulating layer 32 has an exposed surface 321 exposed outside the double-sided copper clad laminate 10 , and the second The conductor layer 42 has an exposed surface 421 exposed outside the double-sided copper clad laminate 10 , the second insulating layer 52 has an exposed surface 521 exposed outside the double-sided copper clad laminate 10 , and the third conductor layer 60 has The exposed surfaces 61 exposed outside the double-sided copper clad laminate 10 are flush with the surface of the first copper foil layer 13 away from the base material layer 11 .

In some embodiments, the first conductive material 20 , the second conductive material 40 and the third conductive material are selected from at least one of conductive copper paste or conductive silver paste.

In some embodiments, the first insulating material 30 and the second insulating material 50 are both made of high-frequency materials, such as liquid crystal polymer (LCP), polytetrafluoroethylene (PTFE) , polyetheretherketone (poly-ether-ether-ketone, PEEK), polyphenylene oxide (polyphenylene oxide, PPO), etc.

It can be understood that the number of conductor layers located in the first groove 101 can be set according to actual needs, and adjacent conductor layers are separated by an insulating layer.

Step S12, please refer to FIG. 12. Circuit fabrication is performed on the first copper foil layer 13 and the second copper foil layer 14 to form a first conductive circuit layer 131 and a second conductive circuit layer 141, thereby obtaining the circuit substrate 100.

The first conductive circuit layer 131 is connected to the two side walls of the first conductor layer 22 located in the first groove 101, and the second conductive circuit layer 141 is connected to the bottom wall of the first conductor layer 22. connected.

In this embodiment, circuit production is performed on the first copper foil layer 13 and the second copper foil layer 14 through image transfer technology.

Referring to FIG. 13a, in some embodiments, the circuit substrate 100 further includes exposed surfaces formed on at least two of the first conductor layer 22, the second conductor layer 42, and the third conductor layer 60. conductive layer 110 on the conductor layer 110 to connect the corresponding conductor layer. As shown in FIG. 13a , the conductive layer 110 is formed on the exposed surfaces of the first conductor layer 22 , the first insulating layer 32 , and the second conductor layer 42 to connect the first conductor layer 22 and the second conductor layer 42. As shown in FIG. 13b , the conductive layer 110 is formed on the exposed surfaces of the second conductor layer 42 , the second insulating layer 52 and the third conductor layer 60 to connect the second conductor layer 42 and the third conductor layer 60 . As shown in FIG. 13c , the conductive layer 110 is formed on the first conductor layer 22 , the first insulating layer 32 , the second conductor layer 42 , the second insulating layer 52 and the third conductor. The exposed surface of the layer 60 is connected to the first conductor layer 22 , the second conductor layer 42 and the third conductor layer 60 .

Step S13, please refer to FIG. 14, when the first conductive circuit layer 131, the first conductor layer 22, the second conductor layer 42 and the third conductor layer 60 are away from the second conductive circuit layer 141 A patterned metal layer 70 is formed on the surface.

The patterned metal layer 70 includes a plurality of connection pads 71 arranged at intervals, and each connection pad 71 is provided on the corresponding first conductive circuit layer 131 , the first conductor layer 22 , the second conductor layer 42 and the Third conductor layer 60. In this embodiment, the material of the metal layer 70 is tin.

Step S14, please refer to FIG. 15, filling the insulating material in the gap between the line gaps of the first conductive line layer 131 and the adjacent connection pads 71 to form a third insulating layer 80, and forming a third insulating layer 80 in the second conductive line layer 131. The side of 141 facing away from the first conductive circuit layer 131 is covered with a covering film 90 to obtain a laminated structure 200 . In this embodiment, the insulating material is filled in the circuit gaps of the first conductive circuit layer 131 and the gaps of the patterned metal layer 70 by printing.

The third insulating layer 80 is made of at least one material selected from LCP, PTFE, PEEK, and PPO.

Step S15 , please refer to FIG. 16 , provide another laminated structure 200 , and connect the other laminated structure 200 to the side of the metal layer 70 away from the base material layer 11 to obtain a circuit board 300 . Two covering films 90 are located outside the circuit board 100 .

In the two-layer structure 200, the two first conductor layers 22 are in corresponding positions and are connected through corresponding connection pads 71, the two second conductor layers 42 are in corresponding positions and are connected through corresponding connection pads 71, and the two third conductor layers are in corresponding positions and are connected through corresponding connection pads 71. The layers 60 are positioned correspondingly and connected through corresponding connection pads 71 to form a "loop" type transmission line.

In some embodiments, the first conductor layer 22, the second conductor layer 42, and the third conductor layer 60 are coaxially arranged, the third conductor layer 60 is a high-frequency transmission line, and the second conductor layer 42 is a mask layer, and the first conductor layer 22 is a transmission line or a power line. The two connected second conductor layers 42 are arranged around the two connected third conductor layers 60 to form a full coverage mask.

In other embodiments, the second conductor layer 42 is a transmission line, and the first conductor layer 22 is a mask layer, so that the circuit board 300 has two independent transmission lines without interfering with each other.

Please refer to FIG. 16 again. An embodiment of the present application provides a circuit board 300 including two circuit substrates 100 and a metal layer 70 and a third insulating layer 80 disposed between the two circuit substrates 100 .

Each circuit substrate 100 includes a base material layer 11, a first conductive circuit layer 131, a second conductive circuit layer 141, a first conductor layer 22, a first insulating layer 32, a second conductive layer 42, a second insulating layer 52 and a third Three conductor layers 60. The first conductive circuit layer 131 and the second conductive circuit layer 141 are respectively disposed on two opposite surfaces of the base material layer 11 . The circuit substrate 100 is provided with a first groove 101 that penetrates the base material layer 11 and the first conductive circuit layer 131. The second conductive circuit layer 141 is formed from the first conductive circuit layer 131. Groove 101 is exposed.

The first conductor layer 22 is disposed in the first groove 101 and connected to the first conductive circuit layer 131 and the second conductive circuit layer 141 . The first conductor layer 22 has a second groove 21 , and the first insulating layer 32 is disposed in the second groove 21 . The first insulating layer 32 has a third groove 31 , and the second conductor layer 42 is disposed in the third groove 31 . The second conductor layer 42 has a fourth groove 41 , and the second insulating layer 52 is disposed in the fourth groove 41 . The second insulating layer 52 has a fifth groove 51 , and the third conductor layer 60 is disposed in the fifth groove 51 .

In some embodiments, the first groove 101, the first conductor layer 22, the second groove 21, the first insulating layer 32, the third groove 31, the second The conductor layer 42 , the fourth groove 41 , the second insulating layer 52 and the fifth groove 51 all have a U-shaped cross-section, and the third conductor layer 60 has a rectangular cross-section.

The first conductor layer 22 has an exposed surface 221 exposed outside the circuit substrate 100 , the first insulating layer 32 has an exposed surface 321 exposed outside the circuit substrate 100 , and the second conductor layer 42 has The second insulating layer 52 has an exposed surface 421 exposed outside the circuit substrate 100 , and the third conductor layer 60 has an exposed surface 421 exposed outside the circuit substrate 100 . The exposed surfaces 61 are flush with the surface of the first conductive circuit layer 131 facing away from the base material layer 11 .

The metal layer 70 includes a plurality of connection pads 71 arranged at intervals, and each connection pad 71 is provided on the corresponding first conductive circuit layer 131 , the first conductor layer 22 , the second conductor layer 42 and the second conductor layer 42 . The exposed surface of the three-conductor layer 60 .

The third insulating layer 80 is filled in the circuit gap of the first conductive circuit layer 131 and the gap between adjacent connection pads 71 .

In the two circuit substrates 100 , the two first conductor layers 22 are in corresponding positions and are connected through corresponding connection pads 71 , the two second conductor layers 42 are in corresponding positions and are connected through corresponding connection pads 71 , and the two third conductor layers are in corresponding positions and are connected through corresponding connection pads 71 . The layers 60 are positioned correspondingly and connected through corresponding connection pads 71 to form a "loop" type transmission line.

Covering films 90 are provided on two opposite surfaces of the circuit board 300 . The cover film 90 includes an adhesive layer 91 and a cover layer 92 arranged in a stack. The adhesive layer 91 covers the second conductive circuit layer 141 . The adhesive layer 91 is made of a common adhesive, and the covering layer is made of PET.

The circuit board 300 and its manufacturing method provided by this application are by opening a first groove 101 on the double-sided circuit substrate and arranging multiple conductor layers in the first groove 101, so that the double-sided circuit substrate has a multi-layer circuit substrate. The effect is to reduce the thickness of the circuit substrate, which is conducive to thinning.

In addition, those skilled in the art can also make other changes within the spirit of the present invention. Of course, these changes made based on the spirit of the present invention should be included in the scope of protection claimed by the present invention.

10:Double-sided copper clad laminate 11:Substrate layer 13: First copper foil layer 14: Second copper foil layer 101: First groove 20: First conductive material 21: Second groove 22: First conductor layer 30:The first insulating material 31:Third groove 32: First insulation layer 40: Second conductive material 41:Fourth groove 42: Second conductor layer 50: Second insulation material 51:Fifth groove 52: Second insulation layer 60:Third conductor layer 221, 321, 421, 521, 61: exposed surface 131: First conductive circuit layer 141: Second conductive circuit layer 110: Conductive layer 70:Metal layer 71:Connection pad 80:Third insulation layer 90: Covering film 200:Laminated structure 91: Adhesive layer 92: Covering layer 300:Circuit board 100:Circuit substrate

Figure 1 is a cross-sectional view of a double-sided copper-clad laminate provided by an embodiment of the present application.

Figure 2 is a cross-sectional view after forming grooves on the double-sided copper-clad board shown in Figure 1.

FIG. 3 is a cross-sectional view after forming the first conductive material in the groove shown in FIG. 2 .

FIG. 4 is a cross-sectional view after removing part of the first conductive material shown in FIG. 3 to form a first conductor layer.

FIG. 5 is a cross-sectional view after forming the first insulating material on the first conductor layer shown in FIG. 4 .

FIG. 6 is a cross-sectional view after removing the first insulating layer formed on the part of the insulating material shown in FIG. 5 .

FIG. 7 is a cross-sectional view after forming the first conductive material on the first insulating layer shown in FIG. 6 .

FIG. 8 is a cross-sectional view after removing part of the first conductive material shown in FIG. 7 to form a second conductor layer.

Figure 9 is a cross-sectional view after forming the first insulating material on the second conductor layer.

FIG. 10 is a cross-sectional view after removing part of the first insulating material shown in FIG. 9 to form a second insulating layer.

FIG. 11 is a schematic cross-sectional view after forming a third conductor layer on the second insulating layer shown in FIG. 10 .

Figure 12 is a schematic cross-sectional view of the structure shown in Figure 11 after circuit production.

Figure 13a is a schematic cross-sectional view of a circuit substrate provided by an embodiment of the present application.

Figure 13b is a schematic cross-sectional view of a circuit substrate provided by another embodiment of the present application.

Figure 13c is a schematic cross-sectional view of a circuit substrate provided by another embodiment of the present application.

FIG. 14 is a schematic cross-sectional view after forming a metal layer on the surface of the conductive layer shown in FIG. 12 .

FIG. 15 is a schematic cross-sectional view after a third insulating layer and a cover film are provided on the structure shown in FIG. 14 .

Figure 16 is a schematic cross-sectional view of a circuit board provided by an embodiment of the present application.

without

11:Substrate layer

101: First groove

21: Second groove

22: First conductor layer

31:Third groove

32: First insulation layer

41:Fourth groove

42: Second conductor layer

51:Fifth groove

52: Second insulation layer

60:Third conductor layer

221, 321, 421, 521, 61: exposed surface

131: First conductive circuit layer

141: Second conductive circuit layer

100:Circuit substrate

Claims (10)

A circuit board, which includes a circuit substrate, the circuit substrate includes a base material layer, a first conductive circuit layer, a second conductive circuit layer, a first conductor layer, a first insulating layer and a second conductor layer, the first The conductive circuit layer and the second conductive circuit layer are provided on two opposite surfaces of the base material layer, and the circuit substrate is provided with a first groove penetrating the base material layer and the first conductive circuit layer, so The second conductive circuit layer is exposed from the first groove, and the first conductor layer is disposed in the first groove and connected with the first conductive circuit layer and the second conductive circuit layer, The first conductor layer is provided with a second groove, the first insulating layer is provided in the second groove and has a third groove, and the second conductor layer is provided in the third groove. middle. The circuit board of claim 1, wherein the circuit board further includes a second insulating layer and a third conductor layer, the second conductor layer is provided with a fourth groove, and the second insulating layer is disposed on the A fifth groove is formed in the fourth groove, and the third conductor layer is disposed in the fifth groove. The circuit board of claim 2, wherein the first conductor layer, the first insulating layer, the second conductor layer, the second insulating layer, and the third conductor layer all have surfaces exposed on Each of the exposed surfaces outside the circuit substrate is flush with the surface of the first conductive circuit layer facing away from the base material layer. The circuit board according to claim 2, wherein the cross-sectional shape of the first conductor layer and the second conductor layer is U-shaped, and the cross-sectional shape of the third conductor layer is rectangular. The circuit board according to claim 2, wherein a conductive layer is provided on the exposed surfaces of at least two of the first conductor layer, the second conductor layer and the third conductor layer. The circuit board according to claim 2, wherein the circuit board includes two circuit substrates arranged in a stack, and the two first conductor layers, the two second conductor layers and the two third conductor layers in the two circuit substrates are respectively connected. The circuit board of claim 6, wherein the circuit board further includes a metal layer disposed between two circuit substrates, and the two first conductor layers, the two second conductor layers and the two third conductor layers pass through the respective The metal layers are connected. The circuit board according to claim 1, wherein a covering film is provided on a surface of the second conductive circuit layer facing away from the base material layer. A method for manufacturing a circuit board as described in any one of claims 1-8, including the following steps: A double-sided copper clad laminate is provided, the double-sided copper clad laminate comprising a base material layer and a first copper foil layer and a second copper foil layer disposed on two opposite surfaces of the base material layer; A first groove is formed on the double-sided copper-clad board, the first groove penetrates the base material layer and the first copper foil layer, and part of the second copper foil layer is formed from the first groove. exposed in the trough; Fill the first groove with a first conductive material, and remove part of the first conductive material to form a second groove to obtain a first conductor layer; Fill the second groove with a first insulating material, and remove part of the first insulating material to form a third groove to obtain a first insulating layer; Fill the third groove with a second conductive material, and remove part of the second conductive material to form a fourth groove to obtain a second conductor layer; Fill the fourth groove with a second insulating material, and remove part of the second insulating material to form a fifth groove to obtain a second insulating layer; Fill the fifth groove with a third conductive material to obtain a third conductor layer; Conduct circuit fabrication on the first copper foil layer and the second copper foil layer to form a first conductive circuit layer and a second conductive circuit layer to obtain a circuit substrate. The production method as described in request item 9, which also includes the following steps: The two circuit substrates are butted together, wherein the two first conductor layers, the two first insulating layers, the two second conductor layers, the two second insulating layers and the two third conductor layers are respectively connected.

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