JPH0632386B2 - Multilayer printed wiring board and manufacturing method thereof - Google Patents

Description

TECHNICAL FIELD The present invention relates to a multilayer printed wiring board and a method for manufacturing the same, and in particular, a so-called build in which conductor layers and insulating layers made of a resin having excellent heat resistance are alternately laminated. The present invention relates to an up method multilayer printed wiring board and a method for manufacturing the same.

(Prior Art) In recent years, with the progress of electronic technology, higher densities or higher speeds of arithmetic functions for electronic devices such as large computers have been promoted. As a result, also in the printed wiring board, a multilayer printed wiring board in which wiring circuits are formed in multiple layers is used for the purpose of increasing the density.

Conventionally, as a multilayer printed wiring board, for example, a plurality of circuit boards on which inner layer circuits are formed are laminated by using a prepreg as an insulating layer, heat-pressed and integrated, and then a multilayer printed wiring board is used to connect the layers to each other for conduction. The wiring board was used.

However, in such a multilayer printed wiring board, if an attempt is made to increase the density by increasing the number of layers, the number of through holes for interlayer connection increases, and the space for forming the increased through holes is increased. Therefore, it is difficult to form a complicated wiring circuit to achieve high density or high speed because the degree of freedom for passing the conductor pattern is reduced.

As a multilayer printed wiring board capable of overcoming such difficulties, a build-up method multilayer printed wiring board in which conductor circuits and organic insulating layers are alternately laminated has been actively developed recently. This build-up method multilayer printed wiring board is considered to be the most suitable for ultra-high density and high speed due to its constituent materials and structure, but it does not improve the adhesion between the conductor circuit and the organic insulating layer. It is a big problem to secure and to secure the conduction reliability between the conductor circuits. That is, there are two points: the adhesion between the organic insulating layer and the conductor circuit formed on the organic insulating layer, and the certainty of proper electrical conduction between the conductor circuits formed by sandwiching the organic insulating layer. If the reliability of electrical continuity is not ensured, it is not preferable in terms of reliability of the multilayer printed wiring board, that is, the wiring structure.

Based on this recognition, as a technique already proposed in the past, there is a "wiring structure and its manufacturing method" as disclosed in Japanese Patent Laid-Open No. 59-106136. The wiring structure disclosed in this publication is "a first polymer resin insulating film provided on a substrate,
A lower wiring conductor layer extending on the polymer resin insulation film of
A second polymer resin insulation film covering the first polymer resin insulation film and the underlying wiring conductor layer and having an opening at a predetermined position; and a second polymer resin insulation film on the second polymer resin insulation film. In the wiring structure having at least a portion of the upper wiring conductor which is in contact with the lower wiring conductor through the opening, the first polymer resin film and the second polymer resin insulating film are substantially A wiring structure having the same chemical composition, and the width of the wiring conductor in the lower layer is substantially equal to or smaller than the dimension of the opening. , Which is roughly as follows. That is, as shown in FIG. 4, the wiring structure disclosed in Japanese Unexamined Patent Publication No. 59-106136 has a lower wiring conductor (3) formed on the first polymer resin insulating film (2). ) And the second
Upper layer wiring conductor formed on the polymer resin insulation film (4) of
(6) and the opening formed in the second polymer resin insulation film (4)
(5) is used for electrical continuity. When forming the opening (5), the first polymer resin insulation film (2) is completely cured and the second polymer resin insulation film (4) is semi-cured. As a result, only the second polymer resin insulating film (4) is etched to form the opening (5). In this way, the opening (5) having a required size can be formed without affecting the others, so that the multilayer printed wiring board suitable for high-density wiring can be obtained.

However, in the wiring structure disclosed in JP-A-59-106136, the wiring conductor (6) in the upper layer and the second polymer resin insulating film (4) located on the plate are formed. There is no intention of ensuring adhesion reliability or reliability of electrical continuity between the upper layer wiring conductor (6) and the lower layer wiring conductor (3). Even if it is possible to achieve higher density or higher speed to some extent, the adhesion between the organic insulating layer and the conductor circuit formed on the organic insulating layer,
It has not been possible to reliably ensure the electrical continuity reliability between the conductor circuits formed by sandwiching the organic insulating layer.

Therefore, the inventors of the present invention can form a complicated wiring circuit to realize high density or high speed, and of course, to improve the adhesion between the organic insulating layer and the conductor circuit formed on the organic insulating layer. , As a result of earnest research to provide a multilayer printed wiring board that can secure the electrical continuity reliability between conductor circuits formed by sandwiching an organic insulating layer, as a result of devising the composition of the insulating layer, The inventors have newly discovered that good results can be produced by devising a method of forming a conductor pattern to be connected later to the formed conductor pattern, and completed the present invention.

(Problems to be Solved by the Invention) The present invention has been made based on the above circumstances,
The problems to be solved are a lack of reliability of adhesion between layers in a conventional multilayer printed wiring board and a lack of reliability of electrical connection between conductor patterns.

The object of the present invention is to improve the composition of the insulating layer and to devise a method of forming a conductor pattern to be connected later with respect to the conductor pattern previously formed, thereby forming a complicated wiring circuit. Of course, it is possible to realize high density or high speed, and of course, the adhesiveness between the organic insulating layer and the conductor circuit formed on the organic insulating layer and the inter-conductor circuit formation between the organic insulating layers. It is an object of the present invention to provide a multilayer printed wiring board capable of ensuring electrical conduction reliability and a method for manufacturing the same.

(Means for Solving the Problems) In order to solve the above problems, the means adopted by the present invention is, “A first conductor composed of a plurality of conductor patterns (12a) formed on a substrate (11)”. A layer (12), an insulating layer (14) made of a resin having excellent heat resistance formed thereon while protecting the first conductor layer (12), and further formed on the insulating layer (14) A multilayer printed wiring board comprising: a second conductor layer (13) composed of a plurality of conductor patterns (13a), wherein the second conductor layer (13) and the insulating layer (14) are alternately formed. The insulating layer (14) on the conductor layer (12) is a filler which is a heat-resistant resin fine powder which is pre-cured and has high solubility in an oxidant as compared with a cured product of a photosensitive resin having excellent heat resistance. (A) and a filler which is a heat-resistant fine powder having a lower solubility in the oxidizing agent than the cured product of the photosensitive resin having excellent heat resistance. -(B) and a photosensitive resin having excellent heat resistance, and by treating the surface of the insulating layer (14) with an oxidant, a recess due to dissolution of the filler (A), The printed wiring board has a roughened surface (14a) on which a convex portion made of the remaining filler (B) is formed, and the first conductor layer (12) or the second conductor layer of the printed wiring board.
Part of the conductor pattern that composes (13) (12a) or (13a)
The opening (15) that exposes the whole of the conductor pattern (12
a) is formed on the insulating layer (14) that protects it, and the conductor pattern (12a) in this opening (15) is brought into contact with a part of the second conductor layer (13) formed by electroless plating. This is a multilayer printed wiring board (10) ".

That is, in the multilayer printed wiring board (10) according to the present invention, the multilayer printed wiring board (10) is a first conductor layer (12a) consisting of a plurality of conductor patterns (12a) formed on the substrate (11). 1
2), an insulating layer (14) formed on the first conductor layer (12) while protecting the first conductor layer (12) and made of a resin having excellent heat resistance, and a plurality of insulating layers (14) further formed on the insulating layer (14). Conductor pattern (13
and a second conductor layer (13) consisting of a), in which the second conductor layer (13) and the insulating layer (14) are alternately formed, and which has the following two requirements Is.

As the insulating layer (14), the surface thereof is treated with an oxidizing agent to form a roughened surface (a convex portion formed of the remaining filler (B) and a concave portion formed by melting the filler (A) ( 14a) having a part of the conductor pattern (12a) constituting the first conductor layer (12)
The opening (15) that exposes the whole of the conductor pattern (12
It is possible to form a part of the second conductor layer (13) formed by electroless plating on the conductor pattern (12a) in this opening (15) by forming it on the insulating layer (14) that protects a). That is the requirement.

It is necessary for each insulating layer (14) employed in the multilayer printed wiring board (10) according to the present invention to have a roughened surface (14a) formed on the surface of the insulating layer (14). When forming the next second conductor layer (13) on the upper side, this second conductor layer (1
This is for ensuring the close contact between 3) and the insulating layer (14) by the roughened surface (14a). That is, if the surface of the insulating layer (14) is simply a flat surface, the so-called anchor effect of the second conductor layer (13) formed by electroless plating is not sufficient. In general, the adhesion strength between the resin and the plated metal is very weak, and unless the anchor is positively formed in any state, the adhesion strength of the second conductor layer (13) to the insulating layer (14) will be reduced. It cannot be secured.

Further, for example, it is necessary to form an opening (15) that exposes the entire part of the conductor pattern (12a) forming the first conductor layer (12) in the insulating layer (14) that protects the conductor pattern (12a). The reason is that it is necessary to secure electrical continuity between the second conductor layer (13) to be plated next and the conductor pattern (12a) through the opening (15). That is, the second conductor layer (13) to be plated and the conductor pattern (1
In order to ensure electrical conduction with 2a), it is better to have more parts (area) that are in electrical contact with each other, but this is because the opening (15) of the conductor pattern (12a) This is ensured by exposing the whole.

Furthermore, in order to further ensure electrical conduction between the second conductor layer (13) to be plated and the conductor pattern (12a) or (13a) located therebelow, these conductor pattern (13a)
(12a) or (13a) may be configured as follows. That is, a portion of the conductor pattern (12a) or (13a) that directly contacts the substrate (11) or the first conductor layer (12) is formed by a general metal layer, and at least the portion formed by this metal layer is formed. By forming the composite plating layer (16) on the upper surface, the conductor pattern (12a) or (13a) has a so-called double structure. As a result, the metal layer is firmly adhered to the substrate (11) or the first conductor layer (12), etc., and the composite plating layer (16) on this metal layer is then plated or formed on the composite plating layer (16). This ensures the adhesion of the insulating layer (14).

Then, in order to manufacture such a multilayer printed wiring board (10), "a first conductor layer (12) composed of a plurality of conductor patterns (12a) formed on a substrate (11) and the first conductor layer (12) A first layer consisting of an insulating layer (14) formed on the layer (12) while protecting the layer (12) and made of a resin having excellent heat resistance, and a plurality of conductor patterns (13a) further formed on the insulating layer (14). A multilayer printed wiring board (10) comprising two conductor layers (13) and alternatingly forming these second conductor layers (13) and insulating layers (14) is prepared as described in (a) to (e) below.
The method for manufacturing a multilayer printed wiring board, which is characterized in that it is formed through at least one step.

(A) A filler (A) which is a heat-resistant resin fine powder that has been pre-cured and has a higher solubility in an oxidizing agent than a cured product of a photosensitive resin having excellent heat resistance; The photosensitive resin excellent in heat resistance, which contains a heat-resistant fine powder (B) which is less soluble in the oxidizing agent than the cured product of the photosensitive resin, is added to the multilayer printed wiring board (1).
0) a step of applying the composition on the upper side of the first conductor layer (12) to form a photosensitive resin layer; (b) exposing a predetermined portion of the photosensitive resin layer, and then developing the photosensitive resin layer; A step of forming an insulating layer (14) in a state where an opening (15) exposing at least a part of the conductor pattern (12a) forming at least the first conductor layer (12) of the plate (10) is formed; By dissolving and removing the filler (A) present on the surface portion of the insulating layer (14) using the above-mentioned oxidant to form a concave portion, the filler (B) is left to form a convex portion. A step of roughening the surface of the insulating layer (14); (d) a second conductor layer formed on the insulating layer (14) by electroless plating
Step of forming (13); (e) Step of forming an insulating layer (14) on the surface of the second conductor layer (13). Is adopted.

In this method, first, a filler (B) insoluble in the oxidizing agent
It is necessary to form a photosensitive resin by applying a photosensitive resin having excellent heat resistance, which contains a filler (A) soluble in an oxidant, to the upper side of the second conductor layer (12) to form the photosensitive resin. This is because it is necessary to ensure the adhesion between the one conductor layer (12) or the second conductor layer (13) and each insulating layer (14). That is, as a result, the insulating layer (14) has a recess in which the filler (A) is dissolved and removed,
In addition, the roughened surface (1) having a convex portion with the filler (B) remaining
It is necessary to have 4a).

In the present invention, as the photosensitive resin excellent in heat resistance,
Examples thereof include a photosensitive epoxy resin, a photosensitive polyimide resin, a photosensitive epoxy acrylate resin, and a photosensitive urethane acrylate resin, and those having excellent heat resistance and electrical insulation and stable to ordinary chemicals are preferable. Also, this photosensitive resin does not necessarily have to be completely cured by light,
It does not matter even if it includes a portion that is cured by heat curing.

The filler (A) is a heat-resistant resin fine powder that is pre-cured and has a higher solubility in an oxidant than the cured product of the photosensitive resin. The material of this filler (A) is excellent in heat resistance and electric insulation, stable to ordinary chemicals,
By pre-curing treatment, it becomes difficult to dissolve the photosensitive resin liquid or the dissolution that dissolves this resin,
Furthermore, any resin can be used as long as it has the property of being dissolved by an oxidizing agent such as chromic acid. Particularly, epoxy resin, polyester resin, bismaleimide
At least one selected from the triazine resins is preferable.

The filler (B) is a heat-resistant fine powder having a lower solubility in an oxidizing agent than the cured product of the photosensitive resin. The material of this filler (B) is resin fine powder or inorganic fine powder which is excellent in heat resistance and electrical characteristics and stable to ordinary chemicals.
Any compound having a low solubility in an oxidizing agent such as chromic acid can be used, and at least one selected from fine benzoguanamine resin powder, silica, and alumina is particularly preferable.

Examples of the oxidizer include chromic acid, chromate, permanganate, ozone and the like.

Next, with respect to the material of the conductor layer, materials that are normally used in printed wiring boards such as copper and nickel can be used.

As the first conductor layer, a copper foil such as a same-strength laminated sheet may be used, but a conductor circuit may be directly formed on the insulating layer by plating.

The second conductor layer can be electroless plated or a combination of electroless plated and electrolytic plated.

In addition, such a photosensitive resin layer is added to the multilayer printed wiring board.
(10) is formed on the upper side of the first conductor layer (12) with the opening (15) exposing at least the entire part of the conductor pattern (12a) forming at least the first conductor layer (12) formed. This is necessary because it is necessary to ensure electrical continuity between the second conductor layer (13) to be subsequently plated and the conductor pattern (12a) through the opening (15). That is, the second conductor layer (13) to be plated and the conductor pattern located below it.
In order to ensure electrical continuity with (12a), the more the portion (area) that is in electrical contact, the better, but this is because the opening (15) has a conductive pattern (12a). This is because it is necessary to secure the entire structure by exposing it.

(Operation of the Invention) In the multilayer printed wiring board (10) according to the first aspect, as shown in FIG.
(14) is a rough surface (1) in which a convex portion made of the remaining filler (B) and a concave portion due to the dissolution of the filler (A) are formed by treating the surface with an oxidizing agent.
It has 4a). Therefore, as shown in FIG. 1 (c), an insulating layer having this roughened surface (14a)
By forming the second conductor layer (13) for (14),
The second conductor layer (13) is located below the second conductor layer (13) due to the anchor effect of the convex portion made of the remaining filler (B) and the concave portion caused by the dissolution of the filler (A).
Alternatively, it is surely adhered to the insulating layer (14).

Also, each insulating layer (14) has a first conductor layer (12) or a second conductor layer.
Part of the conductor pattern that composes (13) (12a) or (13a)
Since the opening (15) for exposing the whole of the above is formed, when the second conductor layer (13) is formed by plating on the upper side of the insulating layer (14), this plating causes a part of the conductor pattern (12a ) Or (13a) is formed so as to enclose the whole, and this part of the conductor pattern (12a) or (13a) and the second conductor layer
The adhesion with (13) is strong.

Therefore, in the multilayer printed wiring board (10) according to the first aspect, the adhesiveness between the insulating layer (14) and the conductor circuit formed on the insulating layer (14) and the insulating layer (14) are sandwiched. The certainty of electrical conduction between the conductor circuits is ensured.

The multilayer printed wiring board (10) having the above operation,
The method according to the second claim facilitates its manufacture.

(Example) Next, a multilayer printed wiring board (10) according to the present invention and a method for manufacturing the same will be described in detail based on examples.

Example 1 (1) Glass epoxy copper clad laminate (manufactured by Toshiba Chemical Co., Ltd., trade name: Toshiba Tecolite MEL-4) (this is the substrate (11)
Is laminated with a dry film (manufactured by DuPont: trade name: Liston 1015) and exposed to ultraviolet light through a mask film on which a desired conductor circuit pattern is drawn to print an image. Then, the film is developed with 1.1.1-trichloroethane, the copper in the non-conductor portion is removed using a cupric chloride etching solution, and then the dry film is peeled off with methylene chloride. This allows multiple conductor patterns (1
A first conductor layer (12) consisting of 2a) is formed. [This state is shown in (a) of FIG. (2) 100 parts by weight of 75% acrylate of polyfunctional epoxy resin (made by Yuka Shell, trade name: Epikote 1031S), 25 parts by weight of dipentaerythritol hexaacrylate, benzyl alkyl ketal (made by Ciba Geigy,
Trade name: Irgacure 651) 5 parts by weight, imidazole (manufactured by Shikoku Kasei, trade name: 2P4MHZ) 3 parts by weight, fine silica powder (manufactured by Nippon Shokubai Kagaku Kogyo, trade name: NS Silica X)
-05, average particle size 0.5 μm) 25 parts by weight, epoxy resin fine powder (manufactured by Toray, trade name: Trepearl EP-B, average particle size 0.5 μm) 35 parts by weight, and then while adding butyl cellosolve, Viscosity 2 with a homodisper stirrer
The solution of the photosensitive resin composition was adjusted to 50 cps and then kneaded with three rolls to prepare a solution of the photosensitive resin composition. (3) Then, the solution of the photosensitive resin composition was placed on the wiring board obtained in (1) with a knife coater. Apply using
After leaving it in a horizontal state for 20 minutes, it was dried by touch at 70 ° C. to form a photosensitive resin layer with a thickness of about 50 μm. (4) Then, a black circle of 100 μmφ (this was opened (15 Corresponding to)) is adhered to a photomask film formed on the surface of the photomask, and a
It was exposed to 0 mj / cm ² . By ultrasonically developing this with a mixed solution of chlorocene / butyl cellosolve in an equal amount, an opening that becomes a via hole of 100 μmφ is formed on the wiring board.
(15) was formed. Next, this wiring board is exposed to an ultra-high pressure mercury lamp for about 300 mj / cm ² and further heat-treated at 100 ° C. for 1 hour and then at 150 ° C. for 10 hours to obtain an opening (excellent in dimensional accuracy equivalent to a photomask film) An interlayer insulating layer (14) having 15) was obtained.

At this time, the via hole portion, that is, the lower layer conductor pattern (12a) exposed in the opening (15) has a line width smaller than the diameter of the via hole, and the distance between the conductor pattern (12a) and other conductor patterns is small. Each conductor pattern (1
The effect of increasing the wiring density between 2a) is great.

(5) Then, the interlayer insulating layer (14) is roughened by treating it with a chromic acid aqueous solution having a temperature of 70 ° C. and a concentration of 500 g / min for 15 minutes to neutralize the solution (made by Shipley, trade name: PM95.
Soak in 0) and wash with water.

[This state is shown in Fig. 1 (b). ] Since the interlayer insulating layer (14) contains fine silica particles insoluble in chromic acid and fine epoxy resin particles soluble in chromic acid,
By treating the surface of the interlayer insulating layer (14) with chromic acid, a roughened surface (14a) with a very complicated shape is formed, and the interlayer insulating layer (14)
The feature is that a high adhesion can be obtained when a conductor is formed on the top.

(6) An interlayer insulating layer (14) is prepared by applying a palladium catalyst (manufactured by Zypree, trade name: Cataposit 44) as a pretreatment for electroless plating on a wiring board having a roughened surface of the interlayer insulating layer (14).
After activating its surface and immersing it in an electroless copper plating solution having the composition and conditions shown in Table 1 for 15 minutes, copper having a thickness of about 20 μm is deposited by an electrolytic copper plating solution having the composition and conditions shown in Table 2. It was This forms the second conductor layer (13). [This state is shown in Fig. 1 (c). ] The second conductor layer (13) and the first conductor layer thus formed
(12) is connected to the first conductor layer (1
2) Since it is connected in such a way that it wraps around the first conductor layer
Even if the connection part of (12) is a thin wire, high connection reliability is ensured.

(7) Next, after repeating the steps (1) to (6) twice, and further performing the step (1), the wiring layer shown in FIG. Build-up multilayer wiring board (1
0).

The feature of the present embodiment is that when connecting conductor layers through via holes, high connection reliability can be ensured even if the lower layer conductor portion of the connection portion has a line width smaller than the via hole diameter. The point is that there is no need for pads or the like, and it is possible to make the lower conductor wiring finer and more dense.

Example 2 (1) A glass-epoxy copper-clad laminate (manufactured by Toshiba Chemical Co., Ltd., trade name: Toshiba Tecolite MEL-4) was dipped in an electrolytic copper plating solution whose composition and conditions are shown in Table 3 to remove epoxy resin particles and copper. Approximately 1 composite plating layer (16) on the copper foil surface
It was formed to a thickness of 0 μm.

(2) The formed composite plating layer (16) is immersed in a sulfuric acid-hydrogen peroxide aqueous solution and etched by about 1 μm, and then the temperature is adjusted to 7
By immersing in an aqueous chromic acid solution at 0 ° C. and a concentration of 500 g / minute for 10 minutes, fine particles of epoxy resin (Toray,
Trade name: Trepal EP-B, average particle size 2 μm, etched and neutralized solution (made by Shipley, trade name: PM
950) and then wash with water. [This state is shown in Fig. 2 (a). (3) A dry film (manufactured by DuPont, trade name: Liston 1015) is laminated on the copper clad laminate having the composite plating layer (16) with the surface thus roughened, to obtain a desired conductor. The image is printed by exposing it to ultraviolet light through a mask film on which a circuit pattern is drawn. Then
After developing with 1.1.1-trichloroethane and using a cupric chloride etching solution to remove the composite plating layer (16) and the copper plating layer on the lower surface thereof from the epoxy resin fine particles and copper of the non-conductive portion, Peel off the dry film with methylene chloride. [This state is shown in Fig. 2 (b). (4) By performing the same operations as (2), (3), (4) and (5) in Example 1, interlayer insulation having a via hole at a desired position on a substrate having a first layer conductor wiring. Forming a layer (14),
The surface was roughened. [This state is shown in Fig. 2 (c). ] The interlayer insulating layer (14) thus formed and the first conductor layer
At the interface with (12), the resin solution for the interlayer insulating layer (14) is cured in the recess of the composite plating layer (16) formed on the surface of the first conductor layer (12). Therefore, high adhesion is secured.

(5) Then, the same operation as in (6) of Example 1 was performed to form the second conductor layer (13) so as to wrap the first conductor layer (12) through the via hole. . [This state is shown in FIG. 2 (d)] The second conductor layer (13) and the first conductor layer thus formed
The connection with (12) is made by interposing the composite plating layer (16) on one surface, but by interposing the composite plating layer (16) on the other two surfaces only by the copper plating layer. There is no concern about the increase in conduction resistance, and the conductor layers (12) (1
The connection reliability between 3) is extremely high.

(6) Next, after repeating the steps (1) to (5) twice, and further performing the step (3), the conductor layer (12) shown in (e) of FIG. 2 is obtained. (13) was a four-layer build-up multilayer wiring board (10).

The feature of this embodiment is that the adhesion between the conductor layer (12) or (13) and the interlayer insulating layer (14) formed thereon is not limited to the composite plating layer (16).
Since it is cured by, it is possible to secure high adhesion strength even under extremely severe conditions.

Example 3 (1) By performing the same operation as in (1) of Example 1,
A first conductor layer (12) is formed. [This state is shown in Fig. 3 (a).
Shown in. (2) Next, this wiring board is dipped in an electroless nickel plating solution whose composition and conditions are shown in Table 4, and a composite plating layer (16) made of acrylonitrile butadiene rubber and nickel and the conductor of (1) above. It was formed on the circuit to a thickness of about 20 μm.

(3) The formed composite plating layer (16) is immersed in a dimethylformamide solution for 10 minutes and etched for about 1 μm, and then immersed in a chromic acid aqueous solution having a temperature of 70 ° C. and a concentration of 500 g / for 10 minutes to coexist on the front and back. Acrylonitrile butadiene rubber fine particles (manufactured by Nippon Zeon Co., Ltd., trade name: Nip
O1 Lx531B, average particle size 0.3 μm is etched, and a neutralization solution (manufactured by Shipley, trade name: PM95) is used.
Soak in 0) and wash with water. [This state is shown in FIG.
Shown in (b). (4) Then, the same operation as (2) (3) (4) (5) of Example 1 is performed to form a via hole at a desired position on the substrate having the first conductor layer (12). Interlayer insulation layer with (14)
Was formed and the surface was roughened. [This state is shown in (c) of FIG. 3. ] The interlayer insulating layer (14) thus formed and the first conductor layer
At the interface with (12), the concave portion of the composite plating layer (16) formed on the entire surface of the first conductor layer (12) is cured with the resin liquid for the interlayer insulating layer (14) entering. Therefore, extremely high adhesion is secured.

(5) Next, the same operation as in (6) of Example 1 was performed to form a ninth conductor layer so as to wrap the first conductor layer (12) through the via hole. [This state is shown in FIG. 3 (d). ] The second conductor layer (13) and the first conductor layer thus formed
Since the connection with (12) is made along the entire surface with the composite plating layer (16) interposed, the increase in conduction resistance is unavoidable, but the connection reliability is secured under any condition.

(6) Next, after repeating the steps (1) to (5) twice, and further performing the step (1), the wiring layer shown in (e) of FIG. 3 has four layers. Build-up multilayer wiring board (1
0).

The feature of the present embodiment is that the adhesion with the interlayer insulating layer (14) formed on the conductor layer is strengthened by the composite plating layer (16) over the entire interface, so that extremely severe conditions are required. This is also a point that a high adhesion strength can be secured.

(Effects of the Invention) As described in detail above, according to the present invention, first, the multilayer printed wiring board (10) according to the first claim thereof is provided with "a plurality of conductor patterns formed on the substrate (11)". (12a) consisting of a first conductor layer (12), an insulating layer (14) made of a resin having excellent heat resistance formed on the first conductor layer (12) while protecting the first conductor layer (12), and this insulating layer ( 14) a multi-layered print further comprising a second conductor layer (13) composed of a plurality of conductor patterns (13a) further formed on the second conductor layer (13) and the insulating layer (14) In the wiring board, at least the insulating layer (14) on the first conductor layer (12) is provided with, for example, silica fine particles insoluble in an oxidizing agent such as chromic acid, and, for example, epoxy resin fine particles soluble in an oxidizing agent such as chromic acid. Made of a resin with excellent heat resistance, including
By subjecting the surface of (14) to treatment with an oxidizing agent such as chromic acid, a roughened surface (14a) is formed, in which residual convex portions made of, for example, silica fine particles and concave portions caused by, for example, dissolution of epoxy resin fine particles are formed. ), And the first conductor layer (12) or the second conductor layer of this printed wiring board.
Part of the conductor pattern that composes (13) (12a) or (13a)
The opening (15) that exposes the whole of the conductor pattern (12
a) is formed on the insulating layer (14) that protects it, and the conductor pattern (12a) in this opening (15) is brought into contact with a part of the second conductor layer (13) formed by electroless plating. “There is a feature in the structure.” Therefore, it is possible to form a complicated wiring circuit to realize high density or high speed, and of course, the organic insulating layer and the conductor circuit formed on the organic insulating layer. Thus, it is possible to provide a multilayer printed wiring board that can secure the adhesion and the reliability of electrical conduction between conductor circuits formed by sandwiching an organic insulating layer.

Further, according to the manufacturing method of the second aspect, it is possible to easily manufacture the multilayer printed wiring board (10) having the above effects by using the conventional apparatus as it is.

[Brief description of drawings]

(A) to (d) of FIG. 1 are partially enlarged cross-sectional views sequentially showing a multilayer printed wiring board and a method for manufacturing the same according to the first embodiment of the present invention, and (a) to (e) of FIG. Is the second of the present invention
FIG. 3A to FIG. 3E are partially enlarged cross-sectional views sequentially showing a multilayer printed wiring board and a method for manufacturing the same according to an embodiment.
FIG. 4 is a partially enlarged cross-sectional view showing, in order, a multilayer printed wiring board according to a third embodiment of the present invention and a method for manufacturing the same, and FIG. 4 is a partially enlarged cross-sectional view showing a conventional multilayer printed wiring board. Explanation of symbols 10 ... Multilayer printed wiring board, 11 ... Substrate, 12 ... First conductor layer, 12a ... Conductor pattern, 13 ... Second conductor layer, 13a ...
… Conductor pattern, 14… Insulation layer, 14a… Roughened surface, 15…
… Aperture, 16 …… Composite plating layer.

Claims (2)

[Claims] 1. A first conductor layer made of a plurality of conductor patterns formed on a substrate, and an insulating layer made of a resin excellent in heat resistance formed thereon while protecting the first conductor layer.
A multilayer printed wiring board comprising a second conductor layer formed of a plurality of conductor patterns further formed on the insulating layer, wherein the second conductor layer and the insulating layer are alternately formed, at least on the first conductor layer. The insulating layer is made of a photosensitive resin having excellent heat resistance, which contains the following filler (A) and the following filler (B), and the surface of the insulating layer is treated with an oxidant, The printed wiring board has a roughened surface on which a concave portion formed by melting the filler (A) and a convex portion formed by the remaining filler (B) are formed. An opening that exposes the entire part of the conductor pattern that forms the conductor layer is formed in an insulating layer that protects the conductor pattern, and the conductor pattern in the opening is formed by electroless plating. Multilayer printed wiring board, characterized in that contacting the part of the two conductor layers. Filler (A): Pre-cured heat-resistant resin fine powder having a higher solubility in the oxidizing agent than the cured product of the photosensitive resin having excellent heat resistance; Filler (B): For the heat resistance A heat-resistant fine powder having a lower solubility in the oxidizing agent than that of a cured product of an excellent photosensitive resin. 2. A first conductor layer made of a plurality of conductor patterns formed on a substrate, and an insulating layer made of a resin excellent in heat resistance formed thereon while protecting the first conductor layer.
A multilayer printed wiring board further comprising a second conductor layer formed of a plurality of conductor patterns further formed on the insulating layer, wherein the second conductor layer and the insulating layer are alternately formed. The method of manufacturing a multilayer printed wiring board, which is characterized in that the step (1) is performed at least once. (A) A filler (A) which is a heat-resistant resin fine powder that has been pre-cured and has a higher solubility in an oxidizing agent than a cured product of a photosensitive resin having excellent heat resistance; The photosensitive resin excellent in heat resistance, which contains heat-resistant fine powder filler (B) having a lower solubility in the oxidant than the cured product of the photosensitive resin, is added to the multilayer printed wiring board described above. A step of forming a photosensitive resin layer by coating on the upper side of the first or second conductor layer; (b) exposing a predetermined portion of the photosensitive resin layer, then developing, and at least the multilayer printed wiring board; A step of forming an insulating layer in a state in which an opening exposing the entire part of the conductor pattern forming the first or second conductor layer is formed; (c) existing on the surface portion of the insulating layer by using the oxidizing agent The filler (A) that has The step of roughening the surface of the insulating layer by forming the projections by leaving the filler (B) at the same time as forming the second conductive layer formed by electroless plating on the insulating layer. Step of forming; (e) Step of forming the insulating layer on the surface of the second conductor layer.