JP3806294B2 - Circuit board manufacturing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a circuit board manufacturing method suitable for manufacturing a circuit board such as a large current circuit board using a relatively thick metal plate as a circuit conductor.
[0002]
[Prior art]
When a relatively thick conductor such as a high-current circuit board or a power circuit is required, for example, as proposed in JP-A-8-181417, it is insulated from a circuit conductor punched out of a copper plate by punching. There is a circuit board in which a substrate is laminated and integrated.
The technique proposed in Japanese Patent Laid-Open No. 8-181417 will be described with reference to FIGS.
As shown in FIG. 5, the circuit conductor 101 that forms a predetermined circuit pattern is formed by punching from a copper plate 100. In order to make the positional relationship of the circuit conductors 101 constant, each circuit conductor 101 is fixed to the edge frame conductor 102 or the adjacent circuit conductor 101 by a thin bridge 103.
[0003]
Further, in order to integrate the circuit conductor 101 and the insulating substrate shown in FIG. 5 into a circuit board, the circuit conductor 101 is embedded and integrated in a thermosetting molding resin.
That is, as shown in FIG. 6, the copper plate 100 is set on the inner surface of the movable mold 110, the mold is closed, and the molding resin is filled from the resin injection hole 111 a formed in the fixed mold 111. As a result, the molding resin passes over the circuit conductor 101 through the groove 111b of the fixed mold 111 and fills the entire cavity 112 (a gap formed between the fixed mold 111 and the movable mold 110). That is, the gap 112a other than the circuit conductor 101 is also filled.
[0004]
Thereafter, the circuit conductor 101 and the insulating substrate are integrated to form a through-hole 104 with a drill at the position of the bridge 103 on the circuit board 120 as shown in FIG. 7, and the bridge 103 is cut. Be electrically independent.
Then, after the bridge 103 is cut, surface treatment such as degreasing and roughening is performed, and then a double-sided circuit board is manufactured using a molding die shown in FIG. That is, the two circuit boards 120 are held by the pins 113b and 114b so that the circuit conductor 101 faces between the fixed mold 114 of the molding die and the inner surfaces 114a and 113a of the movable mold 113.
Then, the molding resin is injected and filled between the fixed mold 114 and the movable mold 113 through the resin injection hole 114 c provided in the fixed mold 113. After the molding resin cools or hardens, the circuit board 120 is taken out, and the unnecessary edge frame conductor 102 is cut away to obtain a double-sided circuit board in which the circuit conductors 101 are embedded on both sides of the resin molding.
[0005]
[Problems to be solved by the invention]
By the way, as described above, in the conventional circuit board manufacturing method, a method of embedding and integrating circuit conductors to be a circuit using a resin molding means is used.
Therefore, although the circuit conductor is fixed by the bridge, the bridge is deformed by the injection pressure when the resin is injected into the mold, the circuit conductor is displaced, and a predetermined conductor pattern cannot be obtained. There was a problem.
[0006]
In the conventional circuit board manufacturing method, after the circuit conductor and the insulating substrate are integrated, the bridge is cut to make each circuit conductor electrically independent.
Therefore, the remaining portion 103a of the bridge 103 remains in the circuit conductor 101 as shown in FIG. The distance between the remaining portions 103a must be at least a distance that does not cause a short circuit. Since the distance between the remaining portions 103a is shorter than the distance between the circuit conductors 103, the distance between the circuit conductors 103 must be increased more than necessary. As a result, the arrangement density of the circuit conductors 103 is reduced. There were technical challenges.
[0007]
The present invention has been made to solve the above technical problem, and it is possible to obtain a predetermined conductor pattern without causing displacement of the circuit conductor, and to improve the arrangement density of the circuit conductor. It aims at providing the manufacturing method of the circuit conductor which can be performed.
[0013]
The present invention has been made to achieve the above object, and a circuit board manufacturing method according to the present invention comprises a circuit conductor made of copper foil laminated on a circuit conductor made of copper plate via a prepreg. A circuit board manufacturing method in which a circuit conductor made of a copper plate is provided inside the board, and a circuit conductor made of copper foil is provided on the upper and lower surfaces of the circuit board, wherein a predetermined circuit pattern is formed on one surface of the copper plate. Placing the formed mask and performing half-etching to form a circuit pattern on one surface of the copper plate ; arranging a first prepreg opposite to the circuit pattern forming surface of the copper plate ; and a circuit pattern forming surface; The first copper foil is placed on the surface of the prepreg opposite to the opposite surface, heated and pressurized by hot pressing, and the copper plate and the first copper foil are fixed and integrated by the first prepreg. Etching a circuit pattern non-forming surface side of the copper plate, separating circuit conductors constituting the circuit pattern, forming a predetermined circuit pattern, and arranging a second prepreg on the circuit pattern of the copper plate Further, a second copper foil is disposed, heated and pressed by hot press, and the circuit pattern of the copper plate and the second copper foil are fixed and integrated, and the first and second copper foils are perforated. And a plating process for forming a copper layer on the surface;
The copper layer, the first copper foil, and a part of the second copper foil are etched to form a copper foil circuit pattern on the upper and lower surfaces, and the upper and lower copper foil circuit patterns are electrically formed by the copper layer. And a connecting step.
Thus, when separating the circuit conductors, the circuit conductors are integrated by the prepreg, so that the circuit conductors can be prevented from being displaced. In addition, since the conventional bridge is not provided, the arrangement density of the circuit conductors can be improved.
Further, it is possible to obtain a circuit board that includes at least a circuit pattern composed of a copper plate and a circuit pattern composed of a copper foil, and includes a through hole that electrically connects both circuit patterns.
[0016]
Furthermore, the present invention has been made in order to achieve the above object, and a circuit board manufacturing method according to the present invention is such that a circuit conductor made of copper foil is laminated on a circuit conductor made of copper plate via a prepreg. A circuit board manufacturing method in which a circuit conductor made of a copper plate is provided inside the circuit board, and a circuit conductor made of a copper foil is provided on the upper and lower surfaces of the circuit board, wherein one surface of the two copper plates has a predetermined And a half-etching step of forming a circuit pattern on one surface of each copper plate, and after the etching, a prepreg is opposed to the circuit pattern formation surfaces of the two copper plates. Placing, heating and pressurizing with a hot press, fixing and integrating the two copper plates with the prepreg, and etching the circuit pattern non-forming side of the two copper plates Separating the circuit conductors constituting the circuit pattern, forming a predetermined circuit pattern, and further arranging a prepreg and a first copper foil on the predetermined circuit pattern by hot pressing Fixing and integrating the first and second copper foils on the upper and lower surfaces by heating and pressurizing, plating the first and second copper foils, and forming a copper layer on the surface; and The copper layer, the first copper foil, and a part of the second copper foil are etched to form a copper foil circuit pattern on the upper and lower surfaces, and the upper and lower copper foil circuit patterns are electrically connected by the copper layer. And a step of performing.
[0017]
Thus, when separating the circuit conductors, the circuit conductors are integrated by the prepreg, so that the circuit conductors can be prevented from being displaced. In addition, since the conventional bridge is not provided, the arrangement density of the circuit conductors can be improved .
In addition, this makes it possible to obtain a circuit board including two circuit patterns made of a copper plate, two circuit patterns made of copper foil, and a through hole for electrically connecting the circuit patterns. it can.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
A circuit board according to a first embodiment of the present invention will be described with reference to FIG.
As shown in FIG. 1A, first, a reference hole 1a is formed in a predetermined position of the copper plate 1 by using a drilling means such as a drill.
As the copper plate 1, a copper plate having a thickness of 150 μm to 500 μm is used. This is because the copper plate 1 having a thickness of 150 μm or less is not preferable as a current circuit conductor or a power circuit conductor, and the copper plate 1 having a thickness exceeding 500 μm is not preferable because it takes a long time for etching described later. In the following description, one surface of the copper plate 1 is referred to as an A surface and the other surface is referred to as a B surface.
[0019]
Next, as shown in FIG. 1B, the B surface 1b of the copper plate 1 is etched. At this time, the reference hole 1a of the copper plate 1 is inserted into a predetermined pin, and using this as a reference, a mask on which a predetermined circuit pattern is formed is placed on the B surface 1b and etching is performed. The etching amount at this time is preferably about half of the thickness of the copper plate 1. In the drawing, a portion 1d indicates an etched portion.
Thereby, a predetermined circuit pattern (circuit conductor 1e) is formed on the B surface 1b of the copper plate 1 (the circuit conductor 1e is connected to the A surface 1c of the copper plate 1).
[0020]
After the etching, the substrate 2 is manufactured on the copper plate 1 by hot pressing. That is, as shown in FIG. 1C, the B surface 1b of the etched copper plate 1 is disposed so as to face an adhesive layer such as a prepreg. Next, the whole is integrated by heating and pressing with a hot press (not shown).
Thereby, the copper plate 1 on which a predetermined circuit pattern (circuit conductor) is formed is fixed and integrated with the base 2 made of an adhesive layer such as a prepreg.
Thereafter, as shown in FIG. 1 (d), the A surface 1c of the copper plate 1 is etched, the circuit conductor 1e is separated, and a predetermined circuit pattern is formed.
[0021]
In this way, etching is performed to form a circuit pattern on one surface of the copper plate, and after the etching step, a base is formed on the circuit pattern forming surface side of the copper plate, and the copper plate is fixed to and integrated with the base, and the circuit pattern is formed by etching. Are separated.
Therefore, when the base is formed, the circuit conductor is not separated and constitutes a copper plate, so that it is possible to prevent the circuit conductor from being displaced. In addition, since the conventional bridge is not provided, the arrangement density of the circuit conductors can be improved. Furthermore, since a part of the circuit conductor is embedded in the base body, the circuit conductor can be firmly fixed to the base body as compared with the case where the circuit conductor is simply bonded to the surface of the base body.
[0022]
A second embodiment of the circuit board according to the present invention will be described with reference to FIG.
As shown in FIG. 2A, first, a reference hole 1a is formed at a predetermined position of the copper plate 1 using a drilling means such as a drill. As the copper plate 1, the thing of 150 micrometers-500 micrometers is used similarly to above-described 1st Embodiment.
Then, as shown in FIG. 2B, the B surface 1b of the copper plate 1 is etched. At this time, the reference hole 1a of the copper plate 1 is inserted into a predetermined pin, and using this as a reference, a mask (not shown) on which a predetermined circuit pattern is formed is placed on the B surface 1b and etching is performed. The etching amount at this time is preferably about half of the thickness of the copper plate 1. Thereby, a predetermined circuit pattern is formed on the B surface 1b of the copper plate 1 (the circuit conductor 1e is connected to the A surface 1c of the copper plate 1).
[0023]
Thereafter, the base 2 is manufactured on the copper plate 1 by hot pressing, and the copper foil 3 is formed on the surface of the base 2 opposite to the surface on the copper plate side.
That is, as shown in FIG. 2C, the B surface 1b of the etched copper plate 1 is disposed so as to face an adhesive layer such as a prepreg. Moreover, the copper foil 3 is arrange | positioned on the surface on the opposite side to the copper plate side surface of adhesive layers, such as a prepreg. Next, the whole is integrated by heating and pressing with a hot press (not shown).
Thereby, the copper plate 1 on which the predetermined circuit pattern is formed is fixed and integrated with the base 2 made of an adhesive layer such as a prepreg. A copper foil 3 is fixed and integrated on the opposite surface of the base 2.
Thereafter, as shown in FIG. 2 (d), the A surface 1c of the copper plate 1 is etched, the circuit conductor 1e is separated, and a predetermined circuit pattern is formed.
[0024]
Further, an adhesive layer such as a prepreg is disposed on the A surface 1c side of the copper plate 1, and the copper foil 4 is disposed on the adhesive layer. Then, the whole is integrated by heating and pressing with a hot press (not shown).
Thereby, the circuit conductor 1e which comprises a predetermined circuit pattern is formed inside, and the circuit board by which the copper foils 3 and 4 were provided in the upper and lower surfaces of the base | substrate 2 is formed.
[0025]
Next, a predetermined circuit pattern is formed on the copper foils 3 and 4 formed on the upper and lower surfaces of the circuit board. The circuit pattern can be formed by a conventionally known method.
First, as shown in FIG. 2 (f), a through hole 2a is formed by drilling at a predetermined position of the base 2 using means such as a drill. Thereafter, as shown in FIG. 2G, copper plating is performed on both surfaces of the base 2 and the inner surface of the through hole 2a (a copper plating layer 5 is formed).
Further, as shown in FIG. 2 (h), a mask on which a predetermined circuit pattern is formed is placed on both surfaces of the substrate, and etching is performed to form a predetermined circuit pattern on both surfaces of the substrate 2.
[0026]
As a result, a circuit board having through holes 6 for electrically connecting both surfaces of the base 2 is formed. The circuit pattern formed inside by the through hole 6 and the circuit pattern formed on the surface of the substrate 2 may be electrically connected.
The circuit conductor provided inside the circuit board is suitable for a power circuit, a large current circuit, etc. because of its thick thickness, and the circuit conductor provided on the upper and lower surfaces of the circuit board is thin. Suitable for signal circuits and the like.
[0027]
A third embodiment of the circuit board according to the present invention will be described with reference to FIG.
As shown in FIG. 3A, first, a copper plate 10 and a copper plate 11 are prepared, and reference holes 10a and 11a are formed at predetermined positions of the copper plate 10 and the copper plate 11 using a drilling means such as a drill. As the copper plates 10 and 11, those having a thickness of 150 μm to 500 μm are used as in the first embodiment.
[0028]
Next, as shown in FIG. 3B, the B surface 10b of the copper plate 10 is etched. At this time, the reference hole 10a of the copper plate 10 is inserted into a predetermined pin, and using this as a reference, a mask (not shown) on which a predetermined circuit pattern is formed is placed on the B surface 10b and etching is performed. The etching amount at this time is preferably about half of the thickness of the copper plate 10.
Similarly, the A surface 11c of the copper plate 11 is etched. At this time, the reference hole 11a of the copper plate 11 is inserted into a predetermined pin, and using this as a reference, a mask (not shown) on which a predetermined circuit pattern is formed is placed on the A surface 11c and etching is performed. The etching amount at this time is preferably about half of the thickness of the copper plate 11.
Thus, a predetermined circuit pattern is formed on the B surface 10b of the copper plate 10 and the A surface 11c of the copper plate 11 (circuit conductors are connected on the A surface 10c side of the copper plate 10 and on the B surface 11b side of the copper plate 11). Circuit conductors are connected).
[0029]
The copper plates 10 and 11 thus configured are opposed to each other with the base 2 such as a prepreg interposed therebetween. That is, the B surface 10b of the copper plate 10 and the A surface 11c of the copper plate 11 are opposed to each other. Then, as shown in FIG.3 (c), it heat-presses with a hot press (not shown), and integrates the whole.
[0030]
Thereafter, as shown in FIG. 3 (d), a predetermined position of the base 12 is drilled to form a through hole 12a. Then, as shown in FIG.3 (e), copper plating is performed to both surfaces of the base | substrate 12, and the through-hole 12a (the copper layer 15 is formed).
Further , as shown in FIG. 3 (f) , a mask on which a predetermined circuit pattern is formed is placed on both surfaces of the substrate 12, and etching is performed to form a predetermined circuit pattern on both surfaces of the substrate 12. . As a result, a circuit board having through holes 16 for electrically connecting circuit patterns formed on both surfaces of the base is formed. Further, since a part of the circuit conductor is embedded in the base body, the circuit conductor can be firmly fixed to the base body as compared with the case where the circuit conductor is simply bonded to the surface of the base body. The circuit conductors provided on the upper and lower surfaces of this circuit board are suitable for power supply circuits, large current circuits, and the like because of their thick thickness.
[0031]
A circuit board according to a fourth embodiment of the present invention will be described with reference to FIG.
As shown in FIG. 4A, first, a copper plate 10 and a copper plate 11 are prepared, and reference holes 10a and 11a are formed at predetermined positions of the copper plate 10 and the copper plate 11 using a drilling means such as a drill. As the copper plates 10 and 11, those having a thickness of 150 μm to 500 μm are used as in the first embodiment.
[0032]
Next, as shown in FIG. 4B, the B surface 10b of the copper plate 10 is etched. At this time, the reference hole 10a of the copper plate 10 is inserted into a predetermined pin, and using this as a reference, a mask (not shown) on which a predetermined circuit pattern is formed is placed on the B surface 10b and etching is performed. The etching amount at this time is preferably about half of the thickness of the copper plate 10.
Similarly, the A surface 11c of the copper plate 11 is etched. At this time, the reference hole 11a of the copper plate 11 is inserted into a predetermined pin, and using this as a reference, a mask (not shown) on which a predetermined circuit pattern is formed is placed on the A surface 11c and etching is performed. The etching amount at this time is preferably about half of the thickness of the copper plate 11.
[0033]
Thus, a predetermined circuit pattern is formed on the B surface 10b of the copper plate 10 and the A surface 11c of the copper plate 11 (circuit conductors are connected on the A surface 10c side of the copper plate 10 and on the B surface 11b side of the copper plate 11). Circuit conductors are connected).
[0034]
The copper plates 10 and 11 thus configured are opposed to each other with a base 12 such as a prepreg interposed therebetween. That is, the B surface 10b of the copper plate 10 and the A surface 11c of the copper plate 11 are opposed to each other. Then, as shown in FIG.4 (c), it heat-presses with a hot press (not shown), and integrates the whole. Thereafter, as shown in FIG. 4D, the A surface 10c of the copper plate 10 and the B surface 11b of the copper plate 11 are etched to separate the circuit conductors 10e and 11e, thereby forming a predetermined circuit pattern.
[0035]
Further, an adhesive layer such as a prepreg is arranged on the A surface 10 c side of the copper plate 10 and the B surface 11 b side of the copper plate 11, and copper foils 13 and 14 are further arranged. Then, the whole is integrated by heating and pressing with a hot press (not shown).
As a result, circuit conductors 10e and 11e constituting a predetermined circuit pattern are formed inside, and a circuit board having copper foils 13 and 14 provided on the upper and lower surfaces of the base is formed.
[0036]
Next, a predetermined circuit pattern is formed on the copper foils 13 and 14 formed on the upper and lower surfaces of the circuit board. The circuit pattern can be formed by a conventionally known method.
First, as shown in FIG. 4F, a predetermined position of the base 12 is drilled to form a through hole 12a. Thereafter, as shown in FIG. 4G, copper plating is performed on both surfaces and the through hole of the substrate (a copper plating layer 15 is formed).
Further, as shown in FIG. 4 (h), a mask on which a predetermined circuit pattern is formed is placed on both surfaces of the substrate 12, and etching is performed to form a predetermined circuit pattern on both surfaces of the substrate 12. .
[0037]
As a result, a circuit board having through holes 16 for electrically connecting both sides of the circuit base is formed. The two-layer circuit conductors 10e and 11e provided inside the circuit board are suitable for a power supply circuit, a large current circuit and the like because the thickness is thick, and the circuit conductors provided on the upper and lower surfaces of the circuit board have a thickness of Because it is thin, it is suitable for signal circuits and the like.
[0038]
In the above embodiment, an adhesive layer such as a prepreg is disposed in order to form a substrate on an etched copper plate or to integrate the etched copper plates, and hot press (not shown) is used. The whole is integrated by heating and pressing.
However, the manufacturing method according to the present invention is not particularly limited to the case where an adhesive layer such as a prepreg is used, and the etched copper plate is accommodated in a mold, and the etched copper plate and the molding resin May be integrated, or two half-etched copper plates may be accommodated in a mold and integrated with a molding resin. At this time, the circuit conductor is formed by so-called half-etching (etching about half the plate thickness) (because it is not connected by a bridge as in the prior art), so the circuit conductor is positioned by the molding resin flowing in the mold. A predetermined circuit pattern can be obtained without causing a shift.
[0039]
Further, as the surface treatment of the circuit conductor 11, in addition to the blackening treatment, means for improving the adhesiveness with the molding resin, such as degreasing and roughening, coupling agent treatment, and application of an adhesive may be applied.
Further, as the molding resin, there are thermoplastic resins such as polyethylene terephthalate, polyphenylene sulfide, and polyetherimide, or thermosetting resins such as epoxy, unsaturated polyester, and diallyl terephthalate, and resins having good heat resistance at the soldering temperature. preferable.
[0040]
Moreover, in the said embodiment, although it demonstrated that about half of the board thickness of a copper plate was desirable as an etching amount of a copper plate, it is not specifically limited to this, The etching amount of a copper plate can be adjusted as needed. it can.
[0041]
Furthermore, in the second and fourth embodiments, the circuit pattern is formed by forming the copper foil on the upper and lower surfaces of the substrate. However, without providing this circuit pattern, the circuit pattern by the copper plate is formed through the prepreg or the molding resin. It is also possible to form the circuit board to form a multilayer.
[0042]
【The invention's effect】
As described above, according to the method for manufacturing a circuit conductor according to the present invention, a predetermined circuit pattern can be obtained without causing the circuit conductor to be displaced, and the arrangement density of the circuit conductor can be improved.
[Brief description of the drawings]
FIG. 1 is a drawing for explaining a first embodiment of a circuit board manufacturing method according to the present invention.
FIG. 2 is a diagram for explaining a second embodiment of a circuit board manufacturing method according to the present invention.
FIG. 3 is a drawing for explaining a third embodiment of a circuit board manufacturing method according to the present invention.
FIG. 4 is a view for explaining a fourth embodiment of a circuit board manufacturing method according to the present invention.
FIG. 5 is a plan view showing a conventional circuit conductor.
FIG. 6 is a diagram illustrating a process of forming a conventional circuit board.
FIG. 7 is a diagram illustrating a process showing cutting of a bridge portion of a conventional circuit conductor.
FIG. 8 is a diagram illustrating a process of manufacturing a double-sided board using a conventional circuit conductor.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Copper plate 1a Reference hole 1b B surface 1c A surface 1d Etching part 1e Circuit conductor 2 Base | substrate 2a Through-hole 3 Copper foil 4 Copper foil 5 Copper layer (copper plating layer)
6 Through hole 10 Copper plate 10a Reference hole 10e Circuit conductor 11 Copper plate 11a Reference hole 11e Circuit conductor 12 Base 12a Through hole 13 Copper foil 14 Copper foil 15 Copper layer (copper plating layer)
16 Through hole

Claims (2)

A circuit conductor made of copper foil is laminated on a circuit conductor made of copper plate via a prepreg, a circuit conductor made of copper plate is provided inside the circuit board, and a circuit conductor made of copper foil on the upper and lower surfaces of the circuit board A method of manufacturing a circuit board provided with
Placing a mask having a predetermined circuit pattern on one surface of the copper plate, and performing half-etching to form a circuit pattern on one surface of the copper plate;
The first prepreg is disposed opposite to the circuit pattern forming surface of the copper plate, and the first copper foil is disposed on the surface of the prepreg opposite to the surface facing the circuit pattern forming surface, and heated and pressed by a hot press. Fixing and integrating the copper plate and the first copper foil by the first prepreg, and
Etching the circuit pattern non-forming surface side of the copper plate, separating circuit conductors constituting the circuit pattern, and forming a predetermined circuit pattern;
A second prepreg is arranged on the circuit pattern of the copper plate, a second copper foil is further arranged, and heated and pressed by a hot press to fix and integrate the circuit pattern of the copper plate and the second copper foil. Process,
Plating step of perforating the first and second copper foils and forming a copper layer on the surface;
The copper layer, the first copper foil, and a part of the second copper foil are etched to form a copper foil circuit pattern on the upper and lower surfaces, and the upper and lower copper foil circuit patterns are electrically formed by the copper layer. Connecting, and
A method for manufacturing a circuit board, comprising: A circuit conductor made of copper foil is laminated on a circuit conductor made of copper plate via a prepreg, a circuit conductor made of copper plate is provided inside the circuit board, and a circuit conductor made of copper foil on the upper and lower surfaces of the circuit board A method of manufacturing a circuit board provided with
Placing a mask having a predetermined circuit pattern on one surface of two copper plates, and performing half-etching to form a circuit pattern on one surface of each copper plate;
After the etching, placing a prepreg opposite to the circuit pattern forming surfaces of the two copper plates, fixing the two copper plates with the prepreg by heating and pressing with a hot press,
Etching the circuit pattern non-forming surface side of the two copper plates, separating circuit conductors constituting the circuit pattern, and forming a predetermined circuit pattern;
A prepreg is further arranged on the predetermined circuit pattern, and first and second copper foils are arranged, and the first and second copper foils are fixed and integrated on the upper and lower surfaces by heating and pressing with a hot press. Process,
Plating step of perforating the first and second copper foils and forming a copper layer on the surface;
The copper layer, the first copper foil, and a part of the second copper foil are etched to form a copper foil circuit pattern on the upper and lower surfaces, and the upper and lower copper foil circuit patterns are electrically formed by the copper layer. Connecting, and
A method for manufacturing a circuit board, comprising:

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