JP2004281437A - Double-sided metal-clad laminated board with filled via hole and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a double-sided metal-clad laminated board with filled via hole that can cope with the increases of the density of a circuit and the mounting density of components without lowering the reliability of the interlayer connection. <P>SOLUTION: In the double-sided metal-clad laminated board with filled via hole having insulating layers and conductive foil layers on its both surfaces, holes formed in an insulating layer provided on lower conductors are plated and electrically connected to upper conductors. The holes have filled via hole structures constituted by filling the holes with conductors and, when the filled via holes are formed, no plating is made on the surfaces of the conductor foil layers provided on both surfaces of the insulating layer. A method of manufacturing the double-sided metal-clad laminated board with filled via hole includes a step of masking the conductive foil layers with protective films from the metal-clad laminated board having the conductive foil layers on both surfaces, a step of forming the holes, and a step of forming the filled via holes by plating. The method also includes a step of peeling the protective film. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【００１３】
【発明の効果】
本発明に従うと層間接続の信頼性を低下させることなく、回路と部品実装の高密度化に対応した、フィルドビア付き両面金属張積層板を提供することができる。
【図面の簡単な説明】
【図１】一般の層間接続について説明するための断面図をしめす。
【図２】本発明のフィルドビア付き両面金属張積層板を説明するための断面図をしめす。
【符号の説明】
１：導電はく
２：絶縁層
３：貫通穴
４：スルーホールめっき
５：ドライフィルムレジスト
６：スルーホールめっき穴
７：スルーホールランド
８：両面プリント回路基板
９：保護フィルム
１０：フィルドビア用穴
１１：フィルドビア
１２：フィルドビア付き両面金属張積層板
１３：フィルドビア付きプリント回路基板[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a double-sided metal-clad laminate with a filled via for a printed wiring board used as a component of an electronic device, and a method for manufacturing the same.
[0002]
[Prior art]
With the recent increase in the density of electronic devices, printed wiring boards have become finer, and high-density circuit wiring is required, and applications are expanding.
[0003]
In the case of a double-sided metal-clad laminate that is a metal-clad laminate that is a material of a conventional printed wiring board, the double-sided metal-clad laminate has a configuration in which an insulating layer and conductive foil are laminated on both surfaces thereof.
FIG. 1 is a cross-sectional view for explaining a general interlayer connection.
Generally, the electrical connection between the layers is made by drilling a through hole in the double-sided metal-clad laminate with a drill or a laser, and then performing through-hole plating to make the electrical connection. (FIGS. 1 (a) to 1 (c)) However, in this method, plating is formed not only on the wall surface of the through-hole hole but also on both surfaces, so that the thickness of the conductive foil increases. Would. (FIG. 1- (c) -4) Therefore, there is a problem that it is not possible to produce a fine pitch conductor circuit with good yield. In addition, a conductor circuit cannot be provided in the through-hole hole portion (FIG. 1- (e) -6), and restrictions on circuit design are increased. Also, as the number of through-holes increases, the area of the through-hole land required around the through-hole also increases, so that the component mounting density and the circuit density cannot be increased (FIG. 1- (e) -7).
[0004]
[Non-patent document 1]
Kenshi Numakura, "Introduction to High Density Flexible Substrates", First Edition, Nikkan Kogyo Shimbun, December 24, 1998, pp. 117-135.
[Problems to be solved by the invention]
The present invention is intended to solve the problem of high density in a double-sided metal-clad laminate for a printed wiring board. The object of the present invention is to secure double-sided metal with filled vias while ensuring the reliability of interlayer connection. To produce a laminated laminate.
[0006]
[Means for Solving the Problems]
The present invention
(1) A double-sided metal-clad laminate having an insulating layer and conductive foils on both sides thereof, wherein a hole formed in the insulating layer on the lower conductor is plated to be electrically connected to the upper conductor. In the double-sided metal-clad laminate with a filled via having a filled via structure in which the hole is filled with a conductor, and having no structure on the double-sided conductive foil when forming the filled via,
(2) a step of masking a conductive foil layer with a protective film from a metal-clad laminate having conductive foils on both sides, a step of drilling, a step of forming a filled via by plating, and a step of peeling off the protective film A method for manufacturing a double-sided metal-clad laminate with filled vias,
(3) A double-sided metal-clad laminate with filled vias, which is obtained by the method for producing a double-sided metal-clad laminate with filled vias according to (2).
(4) a double-sided printed wiring board with filled vias obtained by using the double-sided metal-clad laminate with filled vias according to item 1 or 3;
It is.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described, but these are not limited at all.
FIG. 2 is a cross-sectional view illustrating a double-sided metal-clad laminate with filled vias of the present invention.
As a method for processing a double-sided metal-clad laminate with filled vias, a double-sided metal-clad laminate having a resin such as polyimide or epoxy on an insulating layer having conductive foils on both sides is prepared (FIG. 2- (a)). The conductive foil is masked with a protective film on the double-sided metal-clad laminate. In this case, the material used for the protective film is laminated with a dry film resist. However, as long as the conductive foil has an effect of not being plated, there is no problem if it is formed by printing with ink or the like instead of a film (see FIG. 2- (b)).
Next, a hole is drilled up to the conductive foil insulating layer surface on the opposite side from the protective film surface. When a laser method is used in the drilling step, an opening can be easily formed and a small diameter can be formed (FIG. 2- (c)). Next, it is preferable to remove the resin or resin residue remaining in the holes by a method of wet desmear using an aqueous potassium permanganate solution or an aqueous sodium permanganate solution or dry desmear using plasma, thereby improving the reliability of interlayer connection, which is preferable. .
Next, plating is applied to the inside of the hole to establish conduction. To fill the hole, plating is performed until the hole is filled (FIG. 2- (d)). Then, the protective film is peeled off. By using this double-sided metal-clad laminate with filled vias (FIG. 2- (e), the conductive foil layer is left as it was at the beginning, and the double-sided metal-clad laminate with filled vias in a thin conductive foil state is used. A fine circuit can be created, and the density of component mounting can be increased by providing a component mounting pad on the via (FIG. 2- (f)).
The above is the preparation of the double-sided metal-clad laminate with filled vias. Examples will be described below.
[0008]
【Example】
(Example 1)
As an example, preparation of a double-sided metal-clad laminate with filled vias will be described.
Double-sided copper-clad laminate: NEX-23FE (25T) [manufactured by Mitsui Chemicals, Inc.] Double-sided copper foil 12 μm thick,
A polyimide film having a thickness of 25 μm was laminated with a dry film resist: HR140 (Tokyo Ohka Kogyo Co., Ltd.) as a protective film to protect the copper foil, and a hole having a diameter of φ75 μm was formed from the surface of the protective film by a UV laser. Opening and dry desmear treatment were performed. After the hole was formed, the inside of the hole was subjected to electrolytic copper plating until copper filled the hole. Next, the protective film was peeled off to obtain a double-sided metal-clad laminate with filled vias.
[0009]
(Example 2)
Double-sided copper-clad laminate: NEX-23FE (25T) [manufactured by Mitsui Chemicals, Inc.] Double-sided copper foil 12 μmm thick
Then, a copper foil as a protective film was laminated on a peelable carrier sheet after UV irradiation on a polyimide film having a thickness of 25 μm, a hole having a diameter of φ75 μm was formed from the surface of the protective film by a UV laser, and dry desmear treatment was performed. Thereafter, the inside of the hole was subjected to electrolytic copper plating by the same method as in Example 1 until copper filled the hole. Next, the protective film was peeled off by UV treatment to obtain a double-sided metal-clad laminate with filled vias.
[0010]
(Comparative example)
Plating is performed without using the protective film described in FIG. 2- (b) -11, and the plating is formed on both sides of the conductive foil, and is the same as that of Example 1 except that the thickness of the conductive foil is increased. Double-sided metal-clad laminate with filled vias obtained by the method described above.
[0011]
Table 1 shows the results obtained according to Examples and Comparative Examples.
In the double-sided metal-clad laminates with filled vias of Examples 1 and 2 and Comparative Example, the metal-to-metal connection was reliably bonded at the interlayer connection portion. In the temperature cycle test, there was no disconnection failure and the metal bonding portion was bonded. And the conduction resistance after the temperature cycle test did not change. Thermal shock test: 260 ° C. oil / room temperature oil 100 cycles or more without disconnection and less than 10% change in resistance.
Regarding the circuit density, in Examples 1 and 2, the double-sided metal-clad laminate with filled vias could be formed with a circuit width and a circuit interval (L / S) of 40 μm and 40 μm μm. However, in the case of the comparative example, since the copper foil of FIG. Fine circuit processing could not be performed as compared with the example.
[0012]
[Table 1]

[0013]
【The invention's effect】
According to the present invention, it is possible to provide a double-sided metal-clad laminate with filled vias, which is compatible with high-density circuit and component mounting without lowering the reliability of interlayer connection.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view for explaining a general interlayer connection.
FIG. 2 is a cross-sectional view for explaining a double-sided metal-clad laminate with filled vias of the present invention.
[Explanation of symbols]
1: Conductive foil 2: Insulating layer 3: Through hole 4: Through hole plating 5: Dry film resist 6: Through hole plating hole 7: Through hole land 8: Double-sided printed circuit board 9: Protective film 10: Filled via hole 11 : Filled via 12: Double-sided metal-clad laminate with filled via 13: Printed circuit board with filled via

Claims (4)

An insulating layer, a double-sided metal-clad laminate having conductive foils on both surfaces thereof, in which a hole formed in the insulating layer on the lower conductor is plated and electrically connected to the upper conductor, A double-sided metal-clad laminate with filled vias, having a filled via structure in which the holes are filled with a conductor, and having a structure in which plating is not applied on the double-sided conductive foil when forming the filled vias. It comprises a step of masking a conductive foil layer with a protective film from a metal-clad laminate having conductive foils on both sides, a step of drilling, a step of forming a filled via by plating, and a step of peeling off the protective film. For producing a double-sided metal-clad laminate with filled vias. A double-sided metal-clad laminate with filled vias, which is obtained by the method for producing a double-sided metal-clad laminate with filled vias according to claim 2. A double-sided printed wiring board obtained by using the double-sided metal-clad laminate with a filled via according to claim 1 or 3.

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