JP2003209363A - Manufacturing method for constituent material of multilayer printed wiring board and double side printed wiring board, constituent material of multilayer printed wiring board and double side printed wiring board obtained by the manufacturing method and multilayer printed wiring board obtained by using them - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a constituent material of a printed wiring board using a multilayer composite material having a structure for which at least a thin first bulk copper layer for forming a circuit pattern, a thick second bulk copper layer for forming a bump for obtaining inter-layer continuity of the printed wiring board and an etching barrier layer positioned between the first bulk copper layer and the second bulk copper layer are stacked. <P>SOLUTION: For the constituent material of the multilayer printed wiring board to be used, a support plate 6 is stuck to the surface of the first bulk copper layer 5 of the multilayer composite material, the bump 8 is formed by using the second bulk copper layer 2, a dielectric sheet is piled up on the formation surface of the bump 8, the constituent resin is softened and pressed and thus the dump 8 is passed through the dielectric sheet and obtained. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a printed wiring board and a printed wiring board obtained by the manufacturing method.

[0002]

2. Description of the Related Art In recent years, due to intensifying international competition in printed wiring board manufacturing, how to reduce manufacturing costs and supply inexpensive and high-quality products will increase the profitability of companies and ensure the survival of their businesses. Is very important in.

Therefore, in order to reduce the manufacturing cost, the technique of omitting the interlayer conductive plating process of the through holes of the double-sided or multi-layered printed wiring board having three or more layers and significantly reducing the production cost of the printed wiring board has become widespread. It was For example, a typical manufacturing method is the B ² it method adopted by Toshiba Corporation. If this B ² it method is simply expressed, it functions like a through hole by using a metal paste such as a copper paste or a silver paste in advance on the bonding surface of the copper foil used for manufacturing the printed wiring board with the insulating resin. The bump shape that will form the interlayer conductive conductor is manufactured by the screen printing method and cured, and in this state, FR-4
By stacking it on a dielectric sheet such as a base material under pressure and laminating, the bump-shaped cured metal paste pierces the dielectric sheet and hits the copper foil surface on the opposite surface to form a conduction path between layers. Of.

Then, as a multilayer composite material used for forming a conductor of a printed wiring board used in such a manufacturing method,
As shown in FIG. 8, the first bulk copper layer 5 for forming the circuit pattern by the rolling method / the roughening treatment layer 3 / the etching barrier metal layer 4 / the bump shape for obtaining the interlayer conduction of the multilayer printed wiring board A material has been proposed in which a second bulk copper layer 2 used to form a layer is laminated in a four-layer structure in order, but due to its manufacturing method, it is used to secure adhesion of the first bulk copper layer to a base material. Since it causes flattening of fine copper particles, it is necessary to provide a manufacturing process such as re-roughening treatment for manufacturing a printed wiring board, and further, the first bulk copper layer of the copper foil layer is set to 18 μm or less. However, it was difficult to form a fine pitch circuit.

Therefore, the present inventors have proposed that the drawbacks of the multilayer composite material obtained by the rolling method can be overcome by using the same multilayer composite material having a four-layer structure by using the electrolytic method.

[0006]

However, the multilayer composite material produced by using this electrochemical method has the following problems.
Although it is easy to make the first bulk copper layer less than 18 μm, the first bulk copper layer is used as an ultrathin copper layer of less than 18 μm, particularly 9 μm or less in consideration of the actual process of manufacturing a printed wiring board. Was difficult. not to mention,
It was completely impossible to have a thickness of about 3 μm, which is said to be necessary for forming an operating circuit of an IC chip.

That is, the multilayer composite material is used as schematically shown in FIGS. 9 to 11 as described below. First, the multilayer composite material 1a shown in FIG.
Is etched so that the second copper layer 2 has the shape of the bump 8 as shown in FIG. 9B. If such a multilayer composite material 1a is used, as shown in FIG. 9B, the second copper layer 2 is formed into the bump 8 by etching and the bump 8 is formed.
The fine copper particles of the roughening treatment layer 3 at the positions where the ridges are not formed disappear. However, the etching barrier layer 4 is not the roughening treatment layer 3.
Since the uneven shape of the fine copper particles is transferred, even if the dielectric sheets P are stacked as shown in FIG. 10C, the dielectric sheet P and the first bulk copper layer 5 are The anchor effect is exhibited at the adhesive interface, and the peeling strength is not impaired. Then, as is apparent from FIGS. 10D-1 and 10D-2, the excess etching barrier layer 4 is not etched with copper when the first bulk copper layer 5 is etched to form the circuit 10. It is possible to remove them at the same time.

The multilayer composite material 1a described above is subjected to circuit etching as shown in FIG. 10 (d-1) and becomes a printed wiring board for build-up. On the other hand, FIG.
-2-), after the copper foils 9 are bonded together, inner layer circuit etching is performed as shown in FIG. 10 (d-2-) to form an inner layer material of the multilayer printed wiring board. Further, by stacking these materials as shown in FIG. 11 and press-working, a so-called four-layer substrate can be obtained.

Since the multilayer composite material is used in the manufacturing method as described above, when the first bulk copper layer becomes thin,
As shown in FIG. 9 (b), the product at the time when the etching is performed with the second copper layer 2 in the bump shape disappears,
A uniform flat surface cannot be maintained, the handling property is significantly impaired, and wrinkle defects occur. Even if dielectric sheets are laminated as shown in FIG. 10C, the bumps have poor positional accuracy. .

Against the background described above, even if the thickness of the first bulk copper layer is less than 18 μm, particularly 9 μm or less,
There has been a demand for a manufacturing method using the multilayer composite material, which enables good manufacturing of printed wiring boards.

[0011]

The inventors of the present invention, as a result of diligent research, have come up with the following method for producing a printed wiring board using the multilayer composite material.
The present invention will be described below.

First, "at least a first bulk copper layer for forming a circuit pattern, a second bulk copper layer for forming bumps for obtaining interlayer conduction of a printed wiring board, a first bulk copper layer and a second bulk copper layer A method of manufacturing a constituent material of a multilayer printed wiring board using a multilayer composite material having a structure in which an etching barrier layer existing between a bulk copper layer and the support board is used, the multilayer composite having a work size. A support plate is attached to the surface of the first bulk copper layer of the material, the second bulk copper layer is etched to form bumps, and a dielectric sheet is overlaid on the surface on which the bumps are formed. The bump is penetrated through the dielectric sheet by softening and pressing, and a bump serving as an interlayer conductive conductor of the multilayer printed wiring board is formed on one side of the first bulk copper layer. For example, a manufacturing method of the constituent materials of the multilayer printed wiring board in a state in which laminated support plate on the other side. "A.

Here, "at least a first bulk copper layer for forming a circuit pattern, a second bulk copper layer for forming bumps for obtaining interlayer conduction of a printed wiring board, and a first bulk copper layer and Multi-layer composite material having a structure in which an etching barrier layer existing between two bulk copper layers is laminated "
Means that the etching barrier layer 4 is present between the first bulk copper layer 5 and the second bulk copper layer 2 as shown in FIG. Various variations can be considered. For example, as shown as variation example 1 and variation example 2 in FIG. 1, fine copper grains are provided between the first bulk copper layer 5 and the etching barrier layer 4, or
Fine copper particles may be provided between the bulk copper layer 2 and the etching barrier layer 4 to obtain an anchor effect for securing the bonding strength with the insulating resin of the printed wiring board. If necessary, a surface treatment layer such as a rust preventive treatment may be provided on any surface. Therefore, the expression "at least ..." Was used. this is,
The same meaning is used in the cases described in other claims. Hereinafter, the present invention will be described, but in order to make the description easier to understand, the following description will be given on the assumption that the most preferable multilayer composite material 1a is used.

In the multilayer composite material used here, a first bulk copper layer (hereinafter simply referred to as "first bulk copper layer") for forming a circuit pattern / etching barrier metal layer / roughening treatment layer / It is preferable to use a four-layer structure of a second bulk copper layer (hereinafter, simply referred to as “second bulk copper layer”) used for forming a bump shape for obtaining interlayer conduction of a multilayer printed wiring board. . In particular, it is more preferable that the first bulk copper layer or the second bulk copper layer is used as a reference layer and another layer is formed thereon by using an electrochemical method. This multilayer composite material 1
A schematic cross-sectional view of a can be seen from Variation Example 1 of FIG. This multilayer composite material 1a has a layer structure of first bulk copper layer 5 / etching barrier metal layer 4 / roughening layer 3 / second bulk copper layer 2.

The decisive difference from the multilayer composite material produced by using the conventional rolling method is that all the layer structures are produced by using the electrochemical method. The point is that the initial shape of the fine copper particles that are electrolytically deposited and deposited can be maintained for a long time without the appropriate unevenness shape being flattened by being crushed. And, the etching barrier metal layer 4 of the multilayer composite material 1a according to the present invention
Can have a shape in which surface irregularities created by the fine copper particles of the roughening treatment layer 3 are transferred. Therefore, as shown in FIG. 3B, after etching the second bulk copper layer 2 into a bump shape, the etching barrier metal layer 4 is removed to eliminate the necessity of re-roughening treatment. It is possible.

The roughening treatment layer 3 according to the present invention deposits fine copper grains as shown in the drawing, or chemically etches the surface of the copper foil which will form the second bulk copper layer. It is formed by, for example, directly roughening. For the sake of caution, the description of the roughening treatment layer 3 in the drawings is made by attaching fine fine copper particles,
For the sake of clearer understanding of the explanation, it is described as being extremely schematic and large, and the dimensions such as the thicknesses of other layers do not correspond to the actual product, but are merely schematic representations. It is a thing.

The etching barrier metal layer 4 of the multi-layer composite material is preferably made of nickel, nickel alloy, tin or tin alloy. By using the alkaline copper etching solution, it is possible to dissolve only the copper component and easily leave it.

Next, the second bulk copper layer 2 has a thickness of 50-150.
It is desirable to configure it as a copper layer with a thickness of μm.
Since the second bulk copper layer 2 is used for forming the bump shape, the thickness of the second bulk copper layer 2 is the height of the bump 8 as it is. Therefore, it is considered that the thickness of the second bulk copper layer 2 may be arbitrarily selected and used according to the thickness of the dielectric sheet P used to form the insulating layer, but the height of the bump 8 is low. If the pressure is too high, the bumps 8 cannot break through the dielectric sheet P and the interlayer conductors cannot be formed even if pressure is applied and press molding is performed. Then, when the dielectric sheet P to be used is a FR-4 base material and its thickness is 25 to 100 μm and formability is taken into consideration, for example, a dielectric sheet P having a nominal thickness of 100 μm is used. When used, it can be judged that the height of the bumps 8 of 100 to 150 μm enables the best product processing. The upper limit value of 150 μm is determined in consideration of the protrusion distance from the dielectric sheet P at the top of the bump 8 when the bump 8 penetrates the dielectric sheet P having a nominal thickness of 100 μm. The lower limit value of 50 μm is set in consideration of the case where the dielectric sheet P has a nominal thickness of 25 μm, which is the minimum thickness of the FR-4 base material in the market.

In the present specification, the dielectric sheet is composed of only a resin material capable of forming an interlayer insulating layer of a printed wiring board, a resin material and a glass cloth or aramid required therefor. It is described as a concept including all that can be used in printed wiring board applications, such as those containing a skeleton material such as a non-woven fabric and those containing a dielectric filler for forming a capacitor layer.

Since the first bulk copper layer 5 is used for manufacturing a signal transmission circuit, a power supply circuit, etc. of a printed wiring board, its thickness is arbitrarily determined in consideration of the wiring density of the circuit to be manufactured. It would be nice. Therefore, it is not necessary to particularly limit the thickness of the first bulk copper layer 5. However, in the case of the multilayer composite material used here, 1
It is easy to use as the first bulk copper layer 5 having a thickness of less than 8 μm.

The multi-layer composite material 1a and the support plate 6 described above are laminated as shown in FIG. 2 (a) and laminated as shown in FIG. 2 (b). In this bonding, the multilayer composite material 1a and the support plate 6 may be entirely bonded by using a metal material such as solder or an adhesive as an insert material. However, if the entire surface is adhered by such a method, the removal work of the insert material is required unless the insert material accompanies the support plate and is simultaneously removed in the subsequent removal work of the support plate 6. There is a drawback that it becomes complicated. Therefore, when a metal material is used as the support plate 6, it is preferable to use a method in which the multilayer composite material 1a and the support plate 6 are overlapped and an ultrasonic welding method is used to join only the outer peripheral edge portion 7. . In the ultrasonic welding method, only the outer peripheral edge portion 7 of the work-size multilayer composite material 1a is pressed and sandwiched by the rotating disk-shaped welding tip C and the roller anvil A similar to those used in continuous seam welding, Apply sonic vibration. At the same time, the rotating disc-shaped welding tip C and the roller anvil A are moved along the outer peripheral edge portion 7 of the work size, and only the outer peripheral edge portion 7 is joined as shown in FIG. 2B. This facilitates the work of removing the support plate 6. Moreover, the ultrasonic welding method has an advantage that the joint strength can be easily controlled and the welding can be performed with an accuracy such that the solution does not penetrate. Further, a method of joining only the outer peripheral edge portion 7 with an adhesive is also very practical.

The support plate 6 used in the present invention is a rigid plate having strength capable of holding its own shape,
A metal material or an organic material can be used as long as it is less likely to be damaged in a later etching process or the like. In particular, the support plate is a stainless steel plate,
It is preferable to use an aluminum plate or an aluminum alloy plate. In particular, aluminum or an aluminum alloy has a great advantage in that it can be repeatedly used without being damaged by an acidic copper etching solution and can be easily handled because it is lightweight. The aluminum plate is made of industrially used pure aluminum, and the aluminum alloy is used as a concept that contains alloy elements such as manganese and chromium. The thickness of the support plate 6 may be the minimum thickness that can serve as a reinforcing material when used as described above, and there is no upper limit in particular. However, considering the transportation work of workers,
Since it is desirable to be lighter in terms of workability and production cost, it is considered that there is no need to make it unnecessarily thick, and it is considered that a thickness of about 0.3 mm to 1 mm is sufficient for use. Be done. Furthermore, as a range in which good welding using the ultrasonic welding method is possible, it is considered that the thickness of the support plate 6 in the case of a metal material is most preferably in the range of 0.3 mm to 0.6 mm.

The state in which the support plate 6 is attached as described above is grasped from the side direction, which is shown as a schematic sectional view in FIG. 3 (a). Then, the second bulk copper layer 2 is etched to form the bumps 8 as shown in FIG.
To make the shape of. The bumps 8 are formed by using an etching method. At this time, the presence of the support plate 6 prevents wrinkles or bending even if the first bulk copper layer 5 is an extremely thin layer having a thickness of about 3 μm.

As a result, it becomes possible to facilitate the work of laminating the dielectric sheets P shown in FIG. 4 (c) and enhance the positional accuracy of the bumps 8. The bonding of the dielectric sheets P is performed by stacking the dielectric sheets P on the surface on which the bumps 8 are formed and softening and pressing the constituent resin of the dielectric sheets P to penetrate the bumps 8 into the dielectric sheets P. To do. At this stage, the resin of the dielectric sheet P is heated and softened by heating at a temperature equal to or lower than the curing temperature of the resin to penetrate the bumps 8, and the resin of the dielectric sheet P is not cured but is in a semi-cured state. Keep it as it is. By leaving the resin of the dielectric sheet P in the semi-cured state in this way, it becomes possible to use it as a constituent material OB of the multilayer printed wiring board as described later.

If the support plate 6 is removed at this stage, it becomes an intermediate material without stiffness. Therefore, with the support plate 6 attached, the constituent material O of the multilayer printed wiring board is kept.
It is used as B. This is the constituent material OB of the multilayer printed wiring board according to the present invention in which the bumps 8 serving as the interlayer conductive conductors of the multilayer printed wiring board are provided on one surface side of the first bulk copper layer 5 and the support board 6 is attached to the other surface side. Is.

Further, in the claim, "a circuit is provided on both sides,
In a method for manufacturing a double-sided printed wiring board having bumps which are interlayer conductive conductors between the circuits on both sides, at least a first bulk copper layer for forming a circuit pattern, and a bump for obtaining interlayer conduction of the double-sided printed wiring board A multilayer composite material having a structure in which a second bulk copper layer for forming a layer and an etching barrier layer existing between the first bulk copper layer and the second bulk copper layer are stacked, and the multilayer composite having a work size is formed. A support plate is attached to the surface of the first bulk copper layer of the material, the second bulk copper layer is etched to form bumps, and a dielectric sheet is overlaid on the surface on which the bumps are formed. By softening and pressing, the resin in the dielectric sheet is maintained in a semi-cured state to allow the bumps to penetrate, and the surface of the dielectric sheet on which the bumps have penetrated faces the copper foil adhesive surface. It is obtained by stacking and pressing to form a copper foil layer, then removing the support plate and etching the first bulk copper layer and the copper foil layer located on both sides to form a circuit. And a method for producing a double-sided printed wiring board having bumps which are interlayer conductive conductors. ".

This is a so-called double-sided printed wiring board in which electrical connection between the double-sided circuits is ensured between the circuits formed on both sides of the cured insulating resin layer of the dielectric sheet by using the bumps located in the insulating layer as interlayer conductive conductors. Is a manufacturing method. Therefore, this double-sided printed wiring board can be used as a core material when manufacturing a multilayer printed wiring board, or can be used as it is as a normal double-sided printed wiring board.

This method for producing a double-sided printed wiring board is based on the above-mentioned method for producing the constituent materials of the multilayer printed wiring board, and further adds manufacturing steps. That is,
Using the multilayer composite material 1b, a support plate 6 is attached to the surface of the first bulk copper layer 5, the second bulk copper layer 2 is etched to form bumps 8, and the surface on which the bumps 8 are formed is dielectric. The steps of stacking the body sheets P, softening the constituent resin of the dielectric sheet P, and penetrating the bumps 8 are common. Then, the surface of the dielectric sheet P having the bumps 8 penetrating through it is laminated with the adhesive surface of the copper foil facing each other and pressed to form the copper foil layer 9 as schematically shown in FIG. 4D. To form. At the stage where this press working is completed, the support plate 6 is removed, and the state becomes as schematically shown in FIG. 4 (e). When the support plate 6 is removed, the first bulk copper layer 5 and the copper foil layer 9 located on both sides are removed.
Then, an etching resist layer is formed, the circuit shape is exposed and developed, and etching is performed to perform the circuit 10 as schematically shown in FIG.
Will be completed.

As described above, since the essential parts of the invention of the method of manufacturing the constituent material OB of the multilayer printed wiring board according to the present invention and the method of manufacturing the double-sided printed wiring board DB are common, the multilayer printed wiring board is obtained. It is possible to directly apply the concept applicable to the constituent material OB. Therefore,
"Thought to be the best as the multilayer composite material" and "Proper thickness of the first bulk copper layer and the second bulk copper layer" described in the description of the method for manufacturing the constituent material OB of the multilayer printed wiring board described above. It is possible to directly apply the concepts of "the most preferable support plate bonding means" and "appropriate constituent material of the support plate".

Using the constituent material OB of the multilayer printed wiring board and the double-sided printed wiring board DB obtained by the manufacturing method described above, the multilayer printed wiring board can be easily manufactured. The multilayer printed wiring board referred to in the present specification is a printed wiring board having three or more circuit layers. Those skilled in the art will consider various combinations of the constituent material OB of the multilayer printed wiring board obtained by the manufacturing method according to the present invention and the double-sided printed wiring board DB, and manufacture the multilayer printed wiring board with various layers. It seems possible. Here, a so-called four-layer printed wiring board manufacturing method will be described so that the manufacturing method of the multilayer printed wiring board can be easily understood.

In order to manufacture a four-layer printed wiring board,
As shown in FIG. 5, using the double-sided printed wiring board DB in which the inner layer circuit is formed as a core material, the tips of the bumps 8 project from both sides of the dielectric sheet P of the constituent material OB of the multilayer printed wiring board. The surfaces thus faced are overlapped with each other so as to face each other, and are pressed with the support plate 6 present.
As a result, the state shown in FIG. 5 (g) is obtained. When the pressing process is completed, the support plates 6 located on both sides are removed at this stage, and the first part derived from the constituent material OB of the multilayer printed wiring board is schematically shown in FIG. 6 (h).
The bulk copper layer 5 is exposed on both sides. Then, an etching resist layer is formed on the surfaces of the first bulk copper layer 5 exposed on both sides, and the outer layer circuit shape is exposed and developed, and is etched, thereby forming a four-layer printed wiring board as shown in FIG. 6 (i). The MLB will be completed. At this time, bump 8
By properly arranging the above arrangement, it is possible to secure electrical conduction between the respective layers without providing a post process for forming a through hole or a via hole.

[0032]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a case of manufacturing a constituent material of a multilayer printed wiring board by using a manufacturing method according to the present invention as an embodiment (hereinafter, described as a first embodiment) and a double-sided printed wiring board A case (hereinafter, described as a second embodiment) will be described, and a case (hereinafter, described as a third embodiment) for manufacturing a four-layer printed wiring board using these will be described.

First Embodiment: In this embodiment, the constituent material OB of the above-mentioned multilayer printed wiring board was manufactured.

First, the multilayer composite material 1a was manufactured as follows. The following description will be given with reference to FIGS. 7, 1 and 2. Although the outer layer surface of the multilayer composite material 1a is subjected to zinc anticorrosion treatment, the illustration of the anticorrosion layer is omitted in the drawings. The multilayer composite material 1a used here uses a rolled copper foil made of oxygen-free copper having a thickness of 120 μm for the second bulk copper layer 2 and having smooth both sides as a starting material,
The manufacturing procedure was according to the flow shown in FIG.
First, the rolled copper foil shown in FIG. 7A was pickled. The inside of the pickling tank for the treatment is filled with a dilute sulfuric acid solution having a concentration of 150 g / l and a liquid temperature of 30 ° C., and the adhering oil and fat components are removed by dipping for 30 seconds to remove excess surface oxide film. It was removed and washed with water.

In the second step, fine copper particles are attached and formed on one surface of the rolled copper foil used as the second bulk copper layer 2 by an electrolytic method, and a roughening treatment layer is formed as shown in FIG. 7 (2). Formed 3. A DSE plate is used as a counter electrode in the solution using a copper electrolytic solution, and the DSE plate is placed in parallel with the surface of the rolled copper foil on which the roughening treatment layer 3 is formed, and the rolled copper foil itself is subjected to cathodic polarization. went. The electrolytic solution and the electrolytic conditions used at this time were 10 g / l copper as a copper sulfate-based solution, 150 g / l sulfuric acid, and a liquid temperature of 25.
C, electrolysis time was 10 seconds, and current density was 20 A / dm ² .

After forming the fine copper particles, overcoating was performed for the purpose of preventing the fine copper particles from falling off and increasing the grain size of the fine copper particles. This overcoating is carried out by using a copper sulfate-based solution to coat fine copper particles under smooth plating conditions of 50 g / l copper, 150 g / l sulfuric acid, liquid temperature 45 ° C., current density 80 A / dm ² , and electrolysis time 15 seconds. Copper was uniformly deposited. The roughening treatment layer 3 was formed as described above and washed with water.

When the formation of the roughening treatment layer 3 was completed, as a third step, the etching barrier layer 4 which was not corroded by the copper etching solution was formed on the roughening treatment layer 3. The etching barrier layer 4 in the present embodiment was formed as a nickel layer having a plane conversion of 8.9 g / m ² . In the solution using a nickel electrolytic solution, a stainless plate was used as a counter electrode, and the stainless plate was placed in parallel with the surface of the rolled copper foil on which the roughening treatment layer 3 was formed, so that the roughening treatment layer 3 was formed. The copper foil itself was cathode-polarized. The nickel electrolytic solution and electrolysis conditions used here are nickel sulfate, nickel concentration 20 g / l, liquid temperature 35 ° C., pH 3, current density 5
The condition was A / dm ² . As described above, FIG.
The etching barrier layer 4 was formed as shown in (3) and washed with water.

When the formation of the etching barrier layer 4 was completed, as a fourth step, the first bulk copper layer 5 having a thickness of 3 μm was formed on the etching barrier layer 4 by an electrolytic method. The formation of the first bulk copper layer 5 was performed using a copper sulfate-based solution under smooth plating conditions. The composition and conditions of the copper sulfate solution used here are such that the concentration is 80 g / l copper,
150g / l sulfuric acid, liquid temperature 50 ℃, current density 50A / dm
² and the electrolysis time was 30 seconds.

As described above, a multi-layer composite material 1a characterized by having a laminated state of a four-layer structure schematically shown in FIG. 7 (4) was obtained. In addition, in the present embodiment,
Anticorrosion treatment was performed using zinc. Here, a soluble anode using a zinc plate was used as the anode electrode to maintain the concentration balance of zinc in the solution.
As electrolysis conditions, a zinc sulfate bath was used, the concentrations of 70 g / l sulfuric acid and 20 g / l zinc were used, the liquid temperature was 40 ° C., and the current density was 15 A / dm ² .

Then, as shown in FIG.
A 1.0 mm thick aluminum plate made of industrial pure aluminum of the same size is used as the support plate 6 on the surface of the first bulk copper layer 5 of the multi-layer composite material 1 a having a size of cm × 50 cm by ultrasonic welding. A method of joining only the outer peripheral edge portion 7 having a width of 3 mm was adopted. In the ultrasonic welding method, only the outer peripheral edge portion 7 of the work-size multilayer composite material 1a is pressed and sandwiched by the rotating disk-shaped welding tip C and the roller anvil A, and ultrasonic vibration of 30 kHz is applied. Rotating disk-shaped welding tip C and roller anvil A
I moved while moving.

When the attachment of the support plates 6 is completed,
A bump 8 was formed by sticking a dry film as an etching resist on the surface of the second bulk copper layer 2, exposing it, developing it, and etching it. Subsequently, a prepreg P having a thickness of 100 μm was superposed on the surface on which the bumps 8 were formed, laminated at a press temperature of 150 ° C., and press-molded to obtain a constituent material OB of the multilayer printed wiring board.

Second Embodiment: The double-sided printed wiring board DB was manufactured by further processing the constituent material OB of the multilayer printed wiring board manufactured in the first embodiment in the following procedure. That is, the adhesive surface of the electrolytic copper foil having a nominal thickness of 12 μm is faced and overlapped with the surface of the prepreg P having the bumps 8 penetrating,
A press forming process was performed at 170 ° C. for 1 hour, and an electrolytic copper foil was laminated to form a copper foil layer 9. As a result, it became as schematically shown in FIG.

After this press working was completed, the support plate 6 was removed. At this time, the support plate 6 was removed by cutting off the joined outer peripheral edge portion 7 of the work size to be in a state schematically shown in FIG. 4 (e).
When the removal of the support plate was completed, an etching resist layer was formed using a dry film on the surfaces of the first bulk copper layer 5 and the copper foil layer 9 located on both sides. Then, the circuit shape is exposed and developed on the etching resist layer, and the etching is performed using an acidic copper etching solution.
The circuit 10 was formed as schematically shown in Fig. 1 to obtain a double-sided printed wiring board DB.

Third Embodiment: A four-layered multilayer printed wiring board MLB was manufactured by using the above-mentioned constituent material OB of the multilayer printed wiring board and the double-sided printed wiring board DB in combination. In order to manufacture a 4-layer printed wiring board MLB,
As schematically shown in FIG. 4F, the double-sided printed wiring board DB having the inner layer circuit formed by etching was used as a core material. Then, the surfaces where the tip portions of the bumps 8 project from the prepreg P of the constituent material OB of the multilayer printed wiring board are overlapped on both sides of the core material so as to face each other, and 170 Pressing was performed at 60 ° C. for 60 minutes.

When the press working is completed, the support plates 6 located on both sides are removed at this stage, and the first bulk derived from the constituent material OB of the multilayer printed wiring board is schematically shown in FIG. 6 (h). The copper layer 5 was exposed on both sides. The support plate 6 was removed by cutting off the connection part of the outer peripheral edge portion 7 in a laminated state.

The first bulk copper layer 5 exposed on both sides
A four-layer printed wiring board MLB as shown in FIG. 6 (i) was obtained by forming an etching resist layer on the surface of the above with a dry film, exposing and developing the outer layer circuit shape, and etching.

[0047]

By employing the manufacturing method using the multilayer composite material according to the present invention, it is possible to obtain a multilayer printed wiring board having a thickness of less than 18 μm, which has been impossible in the conventional copper foil for forming a circuit of the multilayer composite material. It is possible to manufacture the constituent materials and the double-sided printed wiring board, and it is possible to dramatically improve the formation yield and the etching reliability of the fine pitch circuit.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a basic layer configuration of a multilayer composite material and variations thereof.

FIG. 2 is a schematic diagram showing a process of processing a multilayer composite material into a multilayer printed wiring board.

FIG. 3 is a schematic diagram showing a process of processing a multilayer composite material into a multilayer printed wiring board.

FIG. 4 is a schematic diagram showing a process of processing a multilayer composite material into a multilayer printed wiring board.

FIG. 5 is a schematic view showing a process of processing a multilayer composite material into a multilayer printed wiring board.

FIG. 6 is a schematic view showing a process of processing a multilayer composite material into a multilayer printed wiring board.

FIG. 7 is a schematic diagram showing a manufacturing process of a multilayer composite material.

FIG. 8 is a schematic diagram showing a manufacturing process of a conventional multilayer composite material.

FIG. 9 is a schematic view showing a process of processing a conventional multilayer composite material into a multilayer printed wiring board.

FIG. 10 is a schematic diagram showing a process of processing a conventional multilayer composite material into a multilayer printed wiring board.

FIG. 11 is a schematic diagram showing a process of processing a conventional multilayer composite material into a multilayer printed wiring board.

[Explanation of symbols]

1,1a Multilayer composite material 2 Second bulk copper layer 3 Roughening layer 4 Etching barrier layer 5 First bulk copper layer 6 Support plate 7 Outer peripheral edge 8 bumps 9 Copper foil layer 10 circuits P Dielectric sheet (prepreg) C welding tip A Laura Anvil OB Multilayer printed wiring board material MLB Multi-layer printed wiring board (4 layers printed wiring board)

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H05K 3/40 H05K 3/40 Z F term (reference) 4E351 AA01 BB01 BB23 BB24 BB30 BB33 BB38 CC17 DD04 DD19 DD52 DD54 GG06 5E317 AA24 BB01 BB12 BB15 CC52 CD25 CD31 GG14 5E339 AB02 AC01 AD03 AD05 BC01 BC02 BD03 BD06 BD11 BE11 FF02 5E346 AA06 AA12 AA15 AA35 AA43 BB01 CC02 CC08 CC32. Title: Composition material for multilayer printed wiring board, method for manufacturing double-sided printed wiring board, constituent material for multilayer printed wiring board obtained by the manufacturing method, double-sided printed wiring board, and multilayer obtained using them Printed wiring board

Claims (15)

[Claims] 1. A first bulk copper layer for forming at least a circuit pattern, a second bulk copper layer for forming bumps for obtaining interlayer conduction of a printed wiring board, a first bulk copper layer and a second bulk. A method for producing a constituent material for a multilayer printed wiring board using a support board and a multilayer composite material having a structure in which an etching barrier layer existing between a copper layer and the support layer is provided, the multilayer composite material having a work size. A support plate is attached to the surface of the first bulk copper layer, the second bulk copper layer is etched to form bumps, a dielectric sheet is overlaid on the surface on which the bumps are formed, and the constituent resin of the dielectric sheet is softened. Then, by pressing the bumps through the dielectric sheet, a bump serving as an interlayer conductive conductor of the multilayer printed wiring board is provided on one side of the first bulk copper layer, A method for manufacturing a constituent material of a multilayer printed wiring board in which a support board is attached to the other surface side. 2. The multi-layer composite material is for forming bumps for obtaining interlayer conduction of a first bulk copper layer / etching barrier metal layer / roughening treatment layer / double-sided printed wiring board for forming a circuit pattern. The method for producing a constituent material of a multilayer printed wiring board according to claim 1, which is a material having a laminated structure of a second bulk copper layer used. 3. The method for producing a constituent material for a multilayer printed wiring board according to claim 1, wherein the first bulk copper layer is a copper foil layer having a nominal thickness of less than 18 μm. 4. The method for producing a constituent material of a multilayer printed wiring board according to claim 1, wherein the second bulk copper layer is a copper foil layer having a nominal thickness of 50 μm or more. 5. The first of said multi-layer composite material of work size.
The sticking of the support plate to the surface of the bulk copper layer is to overlap a work plate of the multilayer composite material with a support plate of substantially the same size and to bond only the outer peripheral edge portion. A method for manufacturing a constituent material for a multilayer printed wiring board according to any one of claims. 6. The method for manufacturing a constituent material of a multilayer printed wiring board according to claim 1, wherein the support board is an aluminum board. 7. A method of manufacturing a double-sided printed wiring board comprising circuits on both sides and bumps which are interlayer conductive conductors between the circuits on both sides, wherein at least a first bulk copper layer for forming a circuit pattern, both sides. A multilayer composite having a structure in which a second bulk copper layer for forming bumps for obtaining interlayer conduction of a printed wiring board and an etching barrier layer existing between the first bulk copper layer and the second bulk copper layer are laminated. Using a material, a support plate is attached to the surface of the first bulk copper layer of the multilayer composite material having a work size, the second bulk copper layer is etched to form bumps, and a dielectric is formed on the surface on which the bumps are formed. By stacking sheets, softening and pressing the constituent resin of the dielectric sheet, the semi-cured state of the constituent resin of the dielectric sheet was maintained and the bumps were penetrated, and the bumps were penetrated. On the surface of the electric sheet, the adhesive surfaces of the copper foils are faced to each other and pressed to form a copper foil layer, then the support plate is removed, and the first bulk copper layer and the copper foil layer located on both sides are removed. A method for manufacturing a double-sided printed wiring board having bumps, which are interlayer conductive conductors, obtained by etching to form a circuit. 8. The multilayer composite material is for forming bumps for obtaining interlayer conduction of a first bulk copper layer / etching barrier metal layer / roughening treatment layer / double-sided printed wiring board for forming a circuit pattern. The method for manufacturing a double-sided printed wiring board having bumps which are interlayer conductive conductors according to claim 7, which is a multilayer composite material having a laminated structure of a second bulk copper layer used. 9. The method for manufacturing a double-sided printed wiring board having bumps which are interlayer conductive conductors according to claim 7, wherein the first bulk copper layer is a copper foil layer having a nominal thickness of less than 18 μm. 10. The double-sided printed wiring board having bumps, which is an interlayer conductive conductor according to claim 7, wherein the second bulk copper layer is a copper foil layer having a nominal thickness of 50 μm or more. Production method. 11. The first of said multi-layer composite material of work size.
The attachment of the support plate to the surface of the bulk copper layer is performed by stacking a support plate having a size similar to the work size of the multilayer composite material and adhering only the outer peripheral edge portion. A method of manufacturing a double-sided printed wiring board, comprising a bump which is the interlayer conductive conductor according to any one of the claims. 12. A method of manufacturing a double-sided printed wiring board having bumps which are interlayer conductive conductors according to claim 7, wherein the support plate is an aluminum plate. 13. A constituent material for a multilayer printed wiring board obtained by the manufacturing method according to claim 1. 14. A double-sided printed wiring board having bumps, which are interlayer conductive conductors, obtained by the manufacturing method according to claim 7. 15. An outer layer constituting material comprising the interlayer conducting conductor according to claim 13 and a double-sided printed wiring board comprising the interlayer conducting conductor according to claim 14 are combined and laminated to obtain 3. Multi-layer printed wiring board with more layers.