WO2001062055A1

WO2001062055A1 - Method of manufacturing wiring board

Info

Publication number: WO2001062055A1
Application number: PCT/JP2001/000776
Authority: WO
Inventors: Hiroyuki Watanabe
Original assignee: Ibiden Co., Ltd.; Adachi, Shinji
Priority date: 2000-02-15
Filing date: 2001-02-02
Publication date: 2001-08-23
Also published as: JP2001230547A

Abstract

The invention provides a method of manufacturing a wiring board, in which conductor patterns are formed with high positional and dimensional accuracy. Aluminum foil (4) is fixed to a stainless steel support board (1), and a conductor layer (6) (copper patterns 6A and 6B) is formed on the aluminum foil (4). Such structures are stacked and hot-pressed with insulating layers (10) in between. Via holes are provided in the insulating layers (10).

Description

Description Wiring board manufacturing method Technical field

The present invention relates to a method for manufacturing a wiring board formed by laminating a conductor layer and an insulating layer. More specifically, the present invention relates to a method for manufacturing a wiring board with an improvement in the position and dimensional accuracy of a pattern of a conductor layer. Background art

Conventionally, multilayer wiring boards have been manufactured by build-up. In other words, a core substrate having conductor layers on both sides of the resin is prepared, and the conductor layers are patterned. Then, an interlayer insulating layer and a conductor layer are successively laminated on the outside. Also, via holes and the like are appropriately provided between the conductor layer and other conductor layers as necessary. However, the above-mentioned method of manufacturing a wiring board has a problem that the positional accuracy of the conductor layer pattern and the via hole is low. Since the core substrate is made of resin, if the core substrate is subjected to thermal treatment such as pressing, the core substrate expands and contracts due to thermal expansion. In this state, patterning of the conductor layer and via holes in the interlayer insulating layer occur. Is formed.

Accordingly, an object of the present invention is to provide a method of manufacturing a wiring board that can form a pattern of a conductor layer with high positional and dimensional accuracy. Disclosure of the invention

SUMMARY OF THE INVENTION An object of the present invention, which has been made to solve this problem, is a method for manufacturing a wiring board in which a conductor pattern and an interlayer insulating layer are alternately laminated, the method comprising: A step of laminating the conductor pattern and the interlayer insulating layer on the holding plate using a heating and pressing process (1), and a step of separating the holding plate and the laminate after the step (1) (2). Contains. Here, a material having rigidity refers to a material having a higher mechanical strength than a resin or the like. Specifically, metallic materials such as stainless steel and ordinary steel are applicable. This kind of material generally has not only excellent mechanical strength but also a small coefficient of thermal expansion and excellent dimensional stability as compared with resin material.

In this method, the lamination of the conductor pattern and the interlayer insulating layer is performed on a rigid holding plate, so that the dimensional accuracy is stable even with a heating and pressing process such as a hot press. Therefore, a wiring board with high position and dimensional accuracy of the conductor pattern and interlayer connection structure is manufactured. Note that the holding plate itself does not form a part of the wiring board, and is removed later.

Further, in the method for manufacturing a wiring board according to the present invention, the step (1) includes the steps of: placing a conductor pattern fixedly held on two rigid holding plates on opposite sides with an interlayer insulating layer interposed therebetween; It is desirable to perform it. By doing so, each conductor pattern is formed with high positional accuracy on the holding plate, and the high positional accuracy is maintained even in the heating and pressing process.

Further, in the method of manufacturing a wiring board of the present invention, a conductor is used as a holding plate, holes are formed in the laminated interlayer insulating layer, and holes are filled by electric plating using the holding plate as a current supply path. To form an interlayer connection structure. In this way, when filling the holes, current is supplied to each of the attachment points via the entire holding plate. For this reason, the plating results are excellent in uniformity of plating thickness and excellent in flatness. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a cross-sectional view showing a state where a conductor layer is formed on a holding plate. Fig. 2 is a cross-sectional view illustrating the situation where two sets of the components shown in Fig. 1 are pressed together.

FIG. 3 is a cross-sectional view showing a state where a second conductor layer is laminated.

FIG. 4 is a cross-sectional view showing a state in which a via hole is formed in the interlayer insulating layer.

FIG. 5 is a cross-sectional view showing a state where a third conductor layer is laminated.

FIG. 6 is a cross-sectional view showing a state in which a via hole is formed in the interlayer insulating layer.

FIG. 7 is a cross-sectional view showing a state where the manufactured wiring board is removed from the holding plate. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, an embodiment of a method of manufacturing a wiring board according to the present invention will be described in detail with reference to the accompanying drawings.

First, a 1 mm-thick holding plate 1 made of stainless steel is prepared. Guide holes 1A, 1A (5 mm0) are formed in the holding plate 1 at both ends in FIG. In addition, an inlet 1B is opened slightly inside the guide hole 1A on the left side of the figure. Guide pins 12 and 12 (5 mm φ, stainless steel) are passed through guide holes 1A and 1A of this holding plate 1, and aluminum foil 4 (20 / m thick) is placed on holding plate 1. I do. Of course, aluminum foil 4 is also pre-drilled at the same position as guide holes 1A, 1A. Then, air is sucked in from inlet 1B. Then, the aluminum foil 4 is fixed in close contact with the holding plate 1.

Next, the conductor layer 6 is laminated on the aluminum foil 4. This lamination is performed as follows. That is, a plating resist 6E (20 zm thick) is formed on the surface of the aluminum foil 4, and then electrolytic copper is applied. At this time, holding plate 1 and Energize with aluminum foil 4. Then, copper patterns 6A and 6B (20 µm thick) are formed in portions where the plating resist 6E is not formed. Thus, the conductor layer 6 is laminated on the aluminum foil 4 as shown in FIG. The copper patterns 6A and 6B thus formed are substantially fixed to the holding plate 1, and have excellent positional and dimensional accuracy. In addition, since the entire holding plate 1 and aluminum foil 4 are widely used as the current supply path, the thickness uniformity is excellent even when plating is performed under conditions of high plating speed. Then, prepare another one that is the same as that shown in Fig. 1 (excluding the conductor layer pattern). Then, as shown in Fig. 2, hot pressing is performed with the two conductor layers 6, 9 facing each other while sandwiching an epoxy resin interlayer adhesive insulating sheet 10 (100m thick). At this time, since the conductor layers 6 and 9 are fixed to the holding plates 1 and 7, respectively, the positional and dimensional accuracy is maintained regardless of the heating and pressing at the time of pressing. Then, when the upper holding plate 7 and aluminum foil 5 are removed, the state shown in Fig. 3 is obtained. At this time, the blank 9C in the conductor layer 9 is located above the pattern 6A in the conductor layer 6.

Next, a via hole that makes electrical connection between pattern 6A and pattern 9A is formed. This is performed as follows. That is, a hole in the interlayer insulation layer 1 0 by laser processing to the blank 9 C and co informal mask (C 0 ₂ laser or the like), to fill the hole by electrically plated with copper. At this time, the holding plate 1 and the aluminum foil 4 are used as current supply paths. Thus, a via hole 12 is formed as shown in FIG. Here, since the current is uniformly supplied through the entire holding plate 1 and the aluminum foil 4, the plating can be performed at high speed and the in-plane uniformity of the plating thickness is high. For this reason, even when there are a plurality of via holes 12, the problem of unevenness depending on the location is unlikely to occur. Also, there is no need to perform chemical plating before electrical plating. The holes for forming the via holes 12 are not limited to the conformal mask method but may be a large window method or a copper direct method. Furthermore, an etching method that does not use a laser may be used. In plating, it is desirable to form a film to protect pattern 9A from corrosion by the plating solution before drilling.

Next, the interlayer insulating layer 11 and the conductor layer 14 are laminated on the conductor layer 9 (Fig. 5). This lamination is performed by hot pressing the same one as shown in Fig. 1, as in the case of laminating the interlayer insulating layer 10 and the conductor layer 9 on the conductor layer 6. In the state of Fig. 5, the copper pattern 14A of the conductor layer 14 is located above the copper pattern 9A of the conductor layer 9, and the conductor layer 14 is located above the copper layer 6B of the conductor layer 6. The copper pattern 14 B is located. In addition, a blank 14C is provided in the copper pattern 14A, and a blank 14D is provided in the copper pattern 14B.

Next, a via hole 16 for electrically connecting the copper pattern 9A and the copper pattern 14A and a via hole 17 for electrically connecting the copper pattern 6B and the copper pattern 14B are formed. (Fig. 6). The via holes 16 and 17 are formed by laser processing and electric plating in the same manner as when the via holes 12 were formed. Finally, remove the guide pins 1 2 and 1 2 and remove them from the holding plate 1, and peel off the aluminum foil 4 from the conductor layer 6. Thus, the wiring board shown in Fig. 7 is manufactured.

As described above in detail, in the present embodiment, each conductor layer is formed while being fixed on a stainless steel holding plate, and is laminated by hot pressing while being fixed on the holding plate. are doing. For this reason, due to the rigidity and low thermal expansion of the holding plate, wiring boards with high positional accuracy of the copper plate and each via hole in each conductor layer are manufactured. Also, when forming copper patterns and filling via holes, the entire holding plate is used as a current supply path. Therefore, high-speed plating is possible and the uniformity of thickness is excellent. Thus, a method of manufacturing a wiring board that can form a conductor layer pattern and the like with good positional and dimensional accuracy has been realized.

The present embodiment is merely an example, and does not limit the present invention in any way. Therefore, naturally, the present invention can be variously improved and modified without departing from the gist thereof.

For example, different materials may be used as long as they are suitable for the purpose. In particular, for the holding plate made of stainless steel in this embodiment, other materials may be used as long as they have the required mechanical strength and a certain degree of low thermal expansion. Plain steel is one of the candidates, but stainless steel is better for corrosion resistance when used repeatedly. Amber alloy (also referred to as invar or invar) is a promising candidate if attention is paid to its low thermal expansion, but stainless steel is superior in terms of supply stability.

Also, the number of layers in the stack may be different. The stacking method may be the ordinary build-up method for the second and higher layers (conductor layers 9 and 14 in Fig. 6). It is also conceivable to use copper foil instead of the aluminum foil that is first attached to the holding plate, and use this as the conductor layer in the wiring board. In that case, the first copper foil should be patterned after the last removal from the holding plate.

Furthermore, in this embodiment, the batch processing method using a flat holding plate has been described, but continuous processing by the reel to reel method is also possible. In other words, a roll of long material is used for each material, and the single-press method is used for pressing. In this case, a stainless steel strip with a thickness of about 0.1 mm may be used as the holding plate. Industrial applicability

As is clear from the above description, according to the present invention, the position and dimensional accuracy There has been provided a method of manufacturing a wiring board that can form a pattern of a conductor layer or the like well.

Claims

The scope of the claims

1. In a method of manufacturing a wiring board in which conductor patterns and interlayer insulating layers are alternately laminated,

(1) laminating a conductor pattern and an interlayer insulating layer on a rigid holding plate using a heating and pressing process;

A method for manufacturing a wiring board, comprising: a step (2) of separating the holding plate and the laminate after the step (1).

2. In the method for manufacturing a wiring board according to claim 1,

The above-mentioned step (1) is carried out by conducting a conductor pattern fixedly held on two rigid holding plates, respectively, with the interlayer insulating layer interposed therebetween. Production method.

3. In the method for manufacturing a wiring board according to claim 1 or 2,

Using a conductor as the holding plate,

Forming a hole in the laminated interlayer insulating layer and filling the hole by electric plating using the holding plate as a current supply path to form an interlayer connection structure. Production method.