JP2004146666A - Multilayered circuit board and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multilayered circuit board having a columnar conductor for interlayer conduction wherein an interlayer insulating layer uses an electrodeposition resin by the electrodeposition method, and to provide a manufacturing method thereof. <P>SOLUTION: A precipitation mask at the electrodeposition is formed at a part on a copper foil 1 of the part acting like an interlayer connection part 2 by a conventional exposure development process by using a dry film resist 3, and the electrodeposition resin serving as the interlayer insulating layer 4 is precipitated on the exposed face of the copper foil 1 by the electrodeposition method. At that stage, the dry film resist 3 is exfoliated to from the opened interlayer connection part 2. Then, after the columnar conductor 5 is formed on the interlayer connection part 2 by the plating method by using the interlayer insulating layer 4 for a mask, a copper foil 6 is uniformly layered on the interlayer insulating layer 4 and the columnar conductor 5, and required wiring layers 7, 8 are simultaneously formed to the copper foils 1, 6 on both sides by the subtractive method. Then the interlayer insulating layer attached copper foil with the columnar conductor formed by the method above is layered from both sides, and other required wiring layers 9, 10 are formed by the subtractive method to manufacture the multilayered circuit board. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a circuit board and a manufacturing method therefor, and more specifically, the present invention has a columnar conductor for interlayer conduction, and uses an electrodeposition resin by an electrodeposition method for an interlayer insulating layer. The present invention relates to a multilayer circuit board and a method for manufacturing the same.
[0002]
[Conventional technology and its problems]
Due to the demand for further reduction in size and weight of electric and electronic devices, the density of wiring on circuit boards has been increasing year by year. In order to meet this demand, single-sided wiring, double-sided wiring, and further multilayering are being promoted.
[0003]
In recent years, in order to obtain electrical continuity with the wiring in the inner layer of a multilayer circuit board, projecting conductors are formed on the wiring or metal foil by etching, plating, printing, or the like, and the insulating resin is laminated here. There is a method in which the protruding conductor penetrates the resin by performing the heat treatment, and furthermore, a metal foil is laminated to obtain conduction between layers through the protruding conductor.
[0004]
However, the penetration of the protruding conductor into the resin is not always stable. If the penetration is insufficient, there is a possibility that poor conduction between layers may occur.
[0005]
[Means for Solving the Problems]
The electrodeposition method is a method of depositing a resin on a current-carrying part, and can be applied to insulation between wirings of a circuit board by selecting an appropriate resin.
[0006]
Therefore, in the present invention, an electrodeposition resin formed by an electrodeposition method is applied as an interlayer insulating layer of a multilayer circuit board, and a multilayer circuit board which does not have a possibility of causing a conduction failure between layers due to a penetration failure is provided. .
[0007]
An electrodeposition resin is formed as an interlayer insulating layer on a metal foil by an electrodeposition technique, and an opening is formed in the electrodeposition resin by pre-processing or post-processing, and the opening is electrolytically or electrolessly plated or a conductive paste. Is filled with a conductor by an appropriate method such as printing.
[0008]
In addition, a columnar conductor is formed on a metal foil by an appropriate method such as plating, etching, transfer, or printing, and the tip of the columnar conductor is formed of a non-conductive material such as a photoresist as necessary, as disclosed in Japanese Patent Application No. 2001-369645. Mask and form an insulating film by electrodeposition.
[0009]
As the electrodeposition resin used for the interlayer insulating layer, a resin having a surface on which a wiring layer is to be formed later adheres to the wiring layer metal is used. Alternatively, if necessary, an adhesive resin layer may be formed between the interlayer insulating layer and the wiring layer metal.
[0010]
If the tip of the columnar conductor is buried with resin, the tip of the columnar conductor may be exposed by polishing. Thus, a metal foil with an interlayer insulating layer having a columnar conductor is formed.
[0011]
Thereafter, a wiring layer is formed on the surface of the interlayer insulating layer facing the metal foil on which the electrodeposition resin is deposited. At this time, as a method for forming the wiring layer, a subtractive method can be applied by bonding a metal foil on the interlayer insulating layer. In this case, wiring can be formed simultaneously with the metal foil on which the electrodeposition resin is deposited.
[0012]
Other methods for forming the wiring include laminating thin metal foil or forming a wet conductive layer by dry or electroless plating such as sputtering or vacuum deposition, and using this as a seed layer, which is semi-additive. Wiring can also be formed by a method.
[0013]
Alternatively, a desired wiring is formed on a peelable substrate, and the wiring is formed by positioning and transferring the wiring to the interlayer insulating layer, or the desired wiring is inverted on the interlayer insulating layer using a photoresist or the like. A full-additive method in which a formed shape is formed and a wiring is formed by electroless plating or the like using this as a mask can also be applied.
[0014]
A required wiring can be formed using the metal foil of the wiring layer and the metal foil with an interlayer insulating layer obtained in this manner.
[0015]
In addition, as another method of forming the wiring, the metal foil is entirely removed, and a thin metal foil is laminated, or a wet conductive layer formed by dry or electroless plating such as sputtering or vacuum deposition is used. It is also possible to form a wiring by using this as a seed layer by a semi-additive method.
[0016]
Alternatively, the metal foil is entirely removed, a desired wiring is separately formed on a peelable substrate, and the wiring is formed by aligning and transferring this with an interlayer insulating layer, or similarly. A full additive method in which the metal foil is entirely removed, a desired wiring is formed on the interlayer insulating layer using a photoresist or the like, and the wiring is formed by electroless plating or the like using the mask as a mask, can also be applied.
[0017]
A circuit board having wiring layers on both surfaces is formed by the above method. On this circuit board, a metal foil with an interlayer insulating layer having a columnar conductor formed by the above method is laminated, and a desired wiring layer is repeatedly formed on the laminated metal foil surface by the above method. Can be manufactured.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be further described with reference to the illustrated embodiments. FIG. 1 is a manufacturing process diagram of a multilayer circuit board according to one embodiment of the present invention.
[0019]
First, as shown in FIG. 1A, a deposition mask for electrodeposition is formed with a dry film resist 3 on a copper foil 1 at a position to be an interlayer connection portion 2 by a normal exposure and development process. Next, an electrodeposition resin to be the interlayer insulating layer 4 is deposited on the exposed surface of the copper foil 1 as shown in FIG.
[0020]
Further, as shown in FIG. 3 (3), the dry film resist 3 is peeled off to form an open interlayer connection portion 2. Therefore, as shown in FIG. 4D, the columnar conductor 5 is formed in the interlayer connection part 2 by plating using the interlayer insulating layer 4 as a mask. Next, a copper foil 6 is uniformly laminated on the interlayer insulating layer 4 and the columnar conductor 5 as shown in FIG.
[0021]
Next, the required wiring layers 7 and 8 are simultaneously formed on the copper foils 1 and 6 on both sides by a subtractive method as shown in FIG. Further, a copper foil with an interlayer insulating layer having a columnar conductor formed by the method of FIGS. 1 to 4 is laminated from both sides, and other necessary wiring is formed by a subtractive method as shown in FIG. The layers 9, 10 are formed to produce a multilayer circuit board. By repeating these steps, the number of layers can be further increased.
[0022]
FIG. 2 is a manufacturing process diagram of a multilayer circuit board according to another embodiment of the present invention. In this embodiment, first, as shown in FIG. 1A, a copper foil 11 having a desired columnar conductor height is formed on a surface of a copper foil 12, and a dry film resist is laminated on the copper foil 11. Then, it is formed by a usual exposure and development process so that a dry film resist 13 serving as an etching mask is left at a predetermined interlayer connection portion.
[0023]
Next, as shown in FIG. 2B, the copper foil 11 is subjected to an etching process to form the columnar conductor 14. Therefore, as shown in FIG. 3C, the interlayer insulating layer 15 is formed by an electrodeposition technique without removing the dry film resist 13 at the tip of the columnar conductor 14.
[0024]
Further, at the stage where the dry film resist 13 is peeled off as shown in FIG. 4D, a copper foil 16 is uniformly laminated on the surface of the interlayer insulating layer 15 and the columnar conductor 14, and as shown in FIG. At the same time, required wiring layers 17 and 18 are formed by a subtractive method.
[0025]
Then, copper foil with an interlayer insulating layer having a columnar conductor obtained by peeling off the dry film resist 13 through the steps of FIGS. 1A to 3C is laminated from both sides, and as shown in FIG. Other required wiring layers 19 and 20 are formed by the active method to manufacture a multilayer circuit board. By repeating these steps, the number of layers can be further increased.
[0026]
【The invention's effect】
According to the present invention, it is not necessary for the columnar conductor to penetrate the resin, so that it is possible to manufacture a multilayer circuit board having no risk of poor interlayer connection.
[Brief description of the drawings]
FIG. 1 is a manufacturing process diagram of a multilayer circuit board according to an embodiment of the present invention.
FIG. 2 is a manufacturing process diagram of a multilayer circuit board according to another embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Copper foil 2 Interlayer connection part 3 Dry film resist 4 Interlayer insulating layer 5 Columnar conductor 6 Copper foil 7 Wiring layer 8 Wiring layer 9 Wiring layer 10 Wiring layer

Claims (7)

A multilayer circuit board, wherein an interlayer insulating layer having a columnar conductor for interlayer conduction is formed of an electrodeposition resin using an electrodeposition technique. 2. The multilayer circuit board according to claim 1, wherein an adhesive resin is interposed between the wiring layer and the electrodeposition resin. A desired wiring layer is formed on the metal foil of the laminate having the wiring layer and the metal foil with an interlayer insulating layer to form a double-sided circuit board, and another metal foil with an interlayer insulating layer is further laminated on the double-sided circuit board. 3. The multilayer circuit board according to claim 1, wherein another wiring layer is formed on said metal foil. In the production of a multilayer circuit board, an opening for obtaining conduction between layers is formed by pre-processing or post-processing on an interlayer insulating layer formed by electrodeposition on a metal foil, and a columnar conductor for interlayer conduction is formed in the opening. Forming a multilayer circuit board. 5. The method according to claim 4, wherein the columnar conductor for interlayer conduction is formed in the interlayer insulating layer by masking a tip portion of the columnar conductor, forming an interlayer insulating layer by an electrodeposition method, and then removing the mask. Manufacturing method of multilayer circuit board. 6. The method for manufacturing a multilayer circuit board according to claim 4, wherein a tip portion of said columnar conductor is polished as required. 7. The method of manufacturing a multilayer circuit board according to claim 4, wherein another metal foil is attached to a side of the interlayer insulating layer facing the metal foil, and another wiring layer is formed on the metal foil.

Images