JP2002164651A - Method for manufacturing multilayer printed wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a multilayer board, comprising a step of manufacturing a multilayer board by a continuous processing method, in which copper foil surfaces of the multilayer board on which the copper foil surfaces are bonded via insulating layers on both the sides of a circuit board for inner layer can be smoothly formed, and the process control is facilitated. SOLUTION: The method comprises a step of laminating one-side copper-clad laminating sheets 1 on both sides of a circuit board 3 for inner layer to manufacture a multilayer board 20 by laminating two long sheet materials 1, having curable adhesive layers 9 on the insulating material surfaces of long one-side copper-clad laminating sheets, on both the sides of the board 3, by integrating the laminate, and by curing the layers 9.

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 multilayer printed wiring board by a continuous method.

[0002]

2. Description of the Related Art In manufacturing a multilayer printed wiring board, conventionally, a prepreg of a predetermined size is superimposed on a surface of a circuit board for an internal layer of a predetermined size provided with an internal circuit, and a copper foil of a predetermined size is further placed thereon. Alternatively, a single-sided copper-clad laminate is stacked, heated and pressed, laminated and integrated to produce a multilayer board by a batch method, and further processing this multilayer board (also referred to as a shield board) to produce a multilayer printed wiring board. It was common to do. However, in the case of manufacturing a multilayer board by a batch method, it is necessary to set a single layer of a circuit board for an inner layer, a prepreg, and a copper foil (or a single-sided copper-clad laminate) in a molding apparatus and perform molding. However, there was a problem that productivity was poor.

A technique for continuously manufacturing a multilayer board for manufacturing a multilayer printed wiring board is disclosed in Japanese Patent Laid-Open No. 60-11 / 1985.
No. 9796 proposes this. In the method proposed in this publication, a long strip-shaped resin-impregnated base material and a long strip-shaped metal foil are formed on the surface of the inner layer circuit board while continuously supplying the inner layer circuit board provided with the inner layer circuit. A multilayer board for a multilayer printed wiring board is manufactured continuously by heating and continuously transferring these layers.

[0004]

The productivity can be improved by continuously manufacturing a multilayer board for a multilayer printed wiring board as described above. However, since the inner layer circuit board has an inner layer circuit formed on the surface, the surface has an uneven surface where the inner layer circuit is convex and the inner layer circuit is concave, and the surface of the inner layer circuit board is impregnated with resin. When a multilayer board is manufactured by laminating a metal foil (mainly a copper foil) via a base material, these irregularities appear on the surface of the metal foil serving as the surface layer of the multilayer board, impairing the surface smoothness, and as a result, There is a problem that it is difficult to form a fine circuit on the metal foil of the multilayer board.

[0005] For this purpose, Japanese Patent Application Laid-Open Nos. 61-120736 and 7-58453 propose that the surface of an inner layer circuit board is coated with a resin. It is not easy to form a resin layer having a uniform thickness by coating or the like, and there is a difficulty in process management that it is difficult to set various conditions.

The present invention has been made in view of the above points, and an object of the present invention is to provide a method for manufacturing a multilayer printed wiring board including a step of manufacturing a multilayer board by a continuous construction method, wherein the circuit for an inner layer is provided. By providing a method of manufacturing a multilayer printed wiring board in which a copper foil surface of a multilayer board in which copper foil is adhered to both sides of the board via an insulating layer can be formed smoothly and process control is easy. is there.

[0007]

According to a first aspect of the present invention, there is provided a method for manufacturing a multilayer printed wiring board, wherein a copper foil is bonded to an insulating material comprising a sheet-shaped base material and a cured product of a resin composition. The two long members forming the curable adhesive layer on the insulating material surface of the single-sided copper-clad laminate of the length are attached to both sides of the inner layer circuit board provided with the inner layer circuit. After laminating the adhesive layer side toward the inner layer circuit board side and laminating and integrating, by curing the adhesive layer, a single-sided copper-clad laminate is laminated on both sides of the inner layer circuit board to form a multilayer. A method for manufacturing a multilayer printed wiring board, comprising a step of manufacturing a board.

In the method for manufacturing a multilayer printed wiring board according to the present invention, a long material having a curable adhesive layer formed on an insulating material surface of a long single-sided copper-clad laminate is used. Therefore, according to this manufacturing method, the copper foil surface of the multilayer board in which the copper foil is bonded to both sides of the inner layer circuit board via the insulating layer can be formed smoothly, and the adhesive can be formed by one-sided application. Since the layers can be formed, there is an advantage that the process management becomes easier as compared with the case where the resin layers are formed on both sides of the inner layer circuit board.

According to a second aspect of the present invention, in the method of manufacturing a multilayer printed wiring board, the single-sided copper-clad laminate is a single-sided copper-clad laminate having a rough insulating material surface. Item 4. A method for producing a multilayer printed wiring board according to item 1.

In the method for manufacturing a multilayer printed wiring board according to the second aspect of the present invention, a single-sided copper-clad laminate in which the insulating material surface of the single-sided copper-clad laminate is formed as a rough surface is used.
It is possible to manufacture a multilayer printed wiring board having high interlayer adhesion strength.

According to a third aspect of the present invention, in the method for manufacturing a multilayer printed wiring board, a long circuit board for the inner layer is used, and the circuit board for the inner layer is continuously fed. A method for manufacturing a multilayer printed wiring board according to claim 1 or 2.

In the method for manufacturing a multilayer printed circuit board according to the third aspect of the present invention, since a long circuit board is used as the inner layer circuit board, the supply of the inner layer circuit board is simplified, and the multi-layering process is more simplified. There are advantages that can be simplified.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention.
In this embodiment, short internal circuit boards 3 are supplied one by one. Inner layer circuits 5 are provided on both upper and lower surfaces (or one surface) of the inner layer circuit board 3 by etching a copper foil. The inner layer circuit board 3 is made of a substrate portion made of a glass cloth base epoxy resin, a glass cloth base polyester resin, a glass cloth base polyphenylene oxide resin, a glass cloth base polyimide resin, a glass cloth base fluororesin, or the like. An inner layer circuit 5 formed by processing a copper foil of a single-sided copper-clad laminate or a double-sided copper-clad laminate composed of an insulating material) and a copper foil can be used.

In this embodiment, a short circuit board 3 for an inner layer is used.
The long members 1 and 1 are stacked on both sides of the first member, and the long members 1 used are prepared as described below. First, although one or a plurality of resin-impregnated base materials impregnated with a resin composition in a long sheet-like base material such as a glass cloth are continuously fed, a long copper foil is coated on one surface with the other. One side of an insulating material consisting of a sheet-shaped substrate and a cured resin composition by a continuous method by continuously laminating a long release film on the surface while continuously feeding them and curing them by passing them through a heat-curing furnace. To produce a long single-sided copper-clad laminate having a copper foil adhered thereto. As a resin composition to be impregnated into a sheet-like substrate such as a glass cloth, a resin having an unsaturated bond such as an unsaturated polyester resin, a diallyl phthalate resin, or a vinyl ester resin is diluted with a vinyl monomer serving as a crosslinking agent and polymerized. Those prepared by adding an initiator can be used, and those obtained by blending a curing agent and a curing accelerator with a solventless epoxy resin can be used. If necessary, talc, clay, calcium carbonate, aluminum hydroxide,
A filler to which an inorganic powder filler such as silica or a fibrous filler such as glass fiber is added can be used. Since these resin compositions do not generate volatile components such as condensed water, they are suitable for producing a copper-clad laminate by a continuous method. In addition, it is also possible to use what laminated | stacked the long prepreg, the long copper foil, and the long release film as the long material 1, and peeled off the long release film after that. .

Further, as the release film, PE is used.
Films of T, polyimide, polyvinylidene chloride, fluororesin and the like can be used. In this embodiment,
As the release film, a film having a rough contact surface with the resin-impregnated base material is used. Therefore, on the insulating material surface of the single-sided copper-clad laminate obtained by curing through a heat-curing furnace, the fine irregularities of the rough surface formed on the release film are transferred and formed as a roughened surface.

A curable adhesive layer made of, for example, an epoxy resin or the like is formed on the insulating material surface (the surface from which the release film has been peeled) of the single-sided copper-clad laminate. As the adhesive used to form the curable adhesive layer, 80 to 80
At 200 ° C., a temporary curing for 3 to 20 minutes results in a semi-cured state, eliminating the stickiness of the surface, and further melting by reheating at 80 to 150 ° C.,
Further, those having a property of completely curing when heated at 150 to 200 ° C. are desirable. The formation of the adhesive layer on the insulating material surface of the single-sided copper-clad laminate is performed, for example, by applying an adhesive to the insulating material surface of the single-sided copper-clad laminate by a roll coater method, a curtain coating method, etc., and temporarily heating and semi-curing By setting it in a state, it can be formed uniformly to a desired thickness. The thickness of the adhesive layer in a semi-cured state is 20 to
It is preferably 100 μm. If it is less than 20 μm,
This is because it is difficult to fill the uneven surface of the inner layer circuit board 3 and void defects may occur. If the thickness exceeds 100 μm, it tends to be difficult to form an adhesive layer having a uniform thickness. In this way, it is possible to obtain a long material 1 having an adhesive layer formed on the insulating material surface of the single-sided copper-clad laminate, which is wound in a roll shape. Since only one side (insulating material side) of the single-sided copper-clad laminate needs to be provided, there is an advantage that the process management becomes easier as compared with the case of forming on both sides.

Then, as shown in FIG. 1, the leading portions of the long members 1, 1 wound in a roll shape are introduced between a pair of heating rolls 6, 6. At that time, the adhesive layers of the long materials 1 and 1 are inside,
The copper foil is introduced so as to be on the outside, and the inner layer circuit board 3 is supplied between the elongated members 1 and 1 before being introduced between the heating rolls 6 and 6. Then, the long materials 1, 1 and the inner layer circuit board 3 are heated and pressed by the heating rolls 6, 6,
It passes between the heating rolls 6 and 6. At this time, the heating rolls 6 and 6 are preferably heated to, for example, about 100 to 150 ° C., and the pressurization is preferably performed, for example, to about 0.5 MPa of the weight of the upper roll. . Further, it is preferable that the atmosphere in which the heating and pressurization are performed by the heating rolls 6 and 6 is set in a reduced pressure state, since voids are hardly generated in the obtained multilayer board. The reduced pressure state in this case is, specifically, 66.6 kPa (about 500 mmHg) to 93.6 kPa.
It is preferable that the pressure is reduced in the range of 3 kPa (about 700 mmHg).

The adhesive layers are further cured through a heating furnace, if necessary, through the heating rolls 6, 6, which are laminated and integrated. Then, the continuously integrated product is cut into a predetermined size, and heated by a batch-type heating device to completely cure the adhesive layer. The heating and curing conditions after the integration may be determined depending on the type of the adhesive to be used. For example, when the type of the adhesive is an epoxy resin, heating at 160 to 200 ° C. for about 1 to 2 hours. Can be completely cured. The term “completely cured” as used herein refers to a state in which physical properties such as adhesive strength and bending strength do not change even after further heating.

In this manner, the single-sided copper-clad laminate 1 is placed above and below the inner circuit board 3 via the adhesive layer 9 as an insulating layer.
1 can be obtained. By subjecting the multilayer board 20 to processing such as through-hole processing and outer layer circuit formation, a multilayer printed wiring board can be manufactured. In addition, it is also possible to use the obtained multilayer board 20 in which an inner layer circuit is formed on a copper foil as the inner layer circuit board 3 again.

FIG. 2 shows a schematic sectional view of the obtained multilayer board 20. As shown in FIG. 2, the multilayer board 20 has a configuration in which single-sided copper-clad laminates 1 and 1 are laminated above and below an inner circuit board 3 via an adhesive layer 9 which is an insulating layer. The single-sided copper-clad laminates 1 and 1 each have a copper foil 7 adhered to an insulating material 8 composed of a sheet-like base material and a cured product of a resin composition. Is not melted, and the unevenness of the inner layer circuit board 3 is prevented from appearing on the surface of the copper foil 7, and the surface smoothness of the copper foil 7 is not impaired.

Further, in this embodiment, the insulating material surface of the single-sided copper-clad laminate 1 is formed to be rough, and the adhesion between the single-sided copper-clad laminate 1 and the adhesive layer 9 is determined by the rough surface. Thus, a multilayer printed wiring board having high interlayer adhesion strength can be manufactured. As a method of forming the insulating material surface of the single-sided copper-clad laminate 1 as a rough surface, in addition to the method of using the rough surface formed on the release film described above, for example, the insulating material of the single-sided copper-clad laminate 1 is used. It is also possible to form a rough surface by subjecting the surface to a roughening treatment such as a corona discharge treatment, a laser irradiation treatment, or a sanding treatment.

Further, in this embodiment, since the raw materials used in the multi-layering process are as simple as the inner-layer circuit board 3 and the long materials 1 and 1, there is an advantage that the multi-layering process can be simplified.

FIG. 3 shows another embodiment (second embodiment) of the present invention. In this embodiment, a flat plate-shaped heat source is used instead of the heating rolls 6 in the embodiment shown in FIG. A heating press 11 having plates 10 and 10
The short circuit board 3 for the inner layer is heated and pressed to be integrated. At that time, the hot plates 10, 10 are, for example, 100 to 150.
It is preferable to heat to about ° C, and it is preferable to pressurize at a pressure of 0.1 to 0.5 MPa for 30 seconds to 3 minutes. The heating press 11
It is preferable to set the atmosphere for heating and pressurizing under reduced pressure, since voids are less likely to be generated in the obtained multilayer board.
The reduced pressure state in this case is, specifically, 66.6 kPa (about 500 mmHg) to 93.3 kPa (about 700 mmHg).
It is preferable to set the pressure in the range of g).

After that, take out from the heating press 11 and
The integrated product is cut into a predetermined size and heated by a batch-type heating device to completely cure the adhesive layer. The heating and curing conditions may be determined according to the type of the adhesive to be used, as described in the embodiment shown in FIG. 1. For example, when the type of the adhesive is epoxy resin, 1 is set.
By heating at 60 to 200 ° C. for about 1 to 2 hours, it can be completely cured. In this manner, a multilayer board 20 in which the long single-sided copper-clad laminates 1 and 1 are laminated on the upper and lower circuit boards 3 for the inner layer via the adhesive layer 9 as an insulating layer can be continuously obtained. By subjecting the multilayer board 20 to processing such as through-hole processing and outer layer circuit formation, a multilayer printed wiring board can be manufactured.

In the embodiment shown in FIG. 3, since the long members 1 and 1 and the circuit board 3 for the inner layer are integrated by using the heating press 11, the pressing is performed in comparison with the case where the heating rolls 6 and 6 are used. There is an advantage that it is easy to lengthen the time and that it can cope with various adhesives.

FIG. 4 shows still another embodiment (third embodiment) of the present invention. In this embodiment, instead of the short inner-layer circuit board 3 in the embodiment shown in FIG. As shown in FIG. 4, a long circuit board 4 for an inner layer is continuously supplied. Since the long internal circuit board 4 is used in this way, the supply of the internal circuit board is simplified, and the third embodiment has an advantage that the multilayering process can be further simplified. The long inner circuit board 4 can be obtained by continuously forming the inner circuit 5 on a copper foil of a long double-sided copper-clad laminate and forming it into a roll.

[0028]

According to the method for manufacturing a multilayer printed wiring board according to the first aspect of the present invention, a long material having a curable adhesive layer formed on an insulating material surface of a long single-sided copper-clad laminate is used. Therefore, according to this manufacturing method, when a multilayer board is manufactured by the continuous method, the copper foil surface of the multilayer board in which the copper foil is bonded to both sides of the inner layer circuit board via the insulating layer is formed smoothly. And the process management is facilitated.

In the method for manufacturing a multilayer printed wiring board according to the second aspect of the present invention, a single-sided copper-clad laminate in which the insulating material surface of the single-sided copper-clad laminate is formed with a rough surface is used. In addition to the effects of the invention, there is also an effect that a multilayer printed wiring board having high interlayer adhesion strength can be manufactured.

In the method for manufacturing a multilayer printed wiring board according to the third aspect of the present invention, a long circuit board is used as the inner layer circuit board. This also has the effect of simplifying the supply and simplifying the multi-layering process.

[Brief description of the drawings]

FIG. 1 is a schematic diagram for explaining a first embodiment of the present invention.

FIG. 2 is an enlarged schematic cross-sectional view showing a part of the multilayer board manufactured by the above.

FIG. 3 is a schematic diagram for explaining a second embodiment of the present invention.

FIG. 4 is a schematic diagram for explaining a third embodiment of the present invention.

[Description of Signs] 1 Single-sided copper-clad laminate 3 Short inner layer circuit board 4 Long inner layer circuit board 5 Inner layer circuit 6 Heat roll 7 Copper foil 8 Insulating material 9 Adhesive layer 10 Hot platen 11 Heat press 20 Multilayer Board

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5E343 AA03 AA07 BB24 BB67 CC01 DD53 DD54 EE22 GG02 GG11 5E346 AA12 AA15 AA26 CC04 CC09 CC10 CC12 CC14 CC31 CC32 CC41 DD02 DD12 EE02 EE06 EE09 EE12 EE13 GG01 HGG15 GG15

Claims (3)

[Claims] 1. A curable adhesive layer is formed on an insulating material surface of a long single-sided copper-clad laminate in which a copper foil is adhered to an insulating material comprising a sheet-shaped base material and a cured product of a resin composition. The two long members are stacked on both sides of the inner layer circuit board provided with the inner layer circuit, with the adhesive layer side of the long member facing the inner layer circuit board side, and integrated. And then curing the adhesive layer to produce a multilayer board by laminating a single-sided copper-clad laminate on both sides of the circuit board for the inner layer, thereby producing a multilayer printed circuit board. Method. 2. The method according to claim 1, wherein the single-sided copper-clad laminate is a single-sided copper-clad laminate having a rough insulating material surface. 3. The production of a multilayer printed wiring board according to claim 1, wherein a long circuit board for the inner layer is used, and the circuit board for the inner layer is continuously fed. Method.