JPH1168315A - Manufacture of multilayer printed wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely protect a Cu-Ni-P needle alloy layer and a conductor circuit from dissolution to be caused by a local galvanic reaction by a method wherein a roughened layer is formed on the surface of the conductor circuit provided to a board, and subjected to a thermal treatment, and then an interlayer insulating film is formed thereon. SOLUTION: A copper foil is laminated on both sides of a glass epoxy resin board 1 respectively for the formation of a copper-plated laminated board, a through-hole 9 is provided to the copper-plated laminated board, and an inner copper pattern 4 is formed on both the surfaces of the board 1 by etching the copper foils. A roughened layer 11 is formed on all the surfaces of the inner copper patterns 4 and the through-hole 9, and resin filler 10 is filled into the through-hole 9. The surface part of the resin filler 10 and the roughened layer 11 are removed to make the surface of the board 1 smooth, an insulator layer 2a and an adhesive layer 2b are formed on both the surfaces of the board 1 respectively so as to form interlayer resin insulating layers 2 of two-layered structure.

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, and more particularly to a method for manufacturing a multilayer printed wiring board. A method for manufacturing a multilayer printed wiring board that can suppress disconnection and the like is proposed.

[0002]

2. Description of the Related Art In recent years, so-called build-up multilayer wiring boards have been receiving attention due to a demand for higher density of the multilayer wiring boards. This build-up multilayer wiring board is manufactured by a method disclosed in, for example, Japanese Patent Publication No. 4-55555. That is, an interlayer resin insulating layer made of a photosensitive electroless plating adhesive is applied on the core substrate, dried, exposed and developed to form an interlayer resin insulating layer having a via hole opening. Then, after the surface of the interlayer resin insulating layer is roughened by treatment with an oxidizing agent or the like, a plating resist obtained by exposing and developing a photosensitive resin layer on the roughened surface is provided. A conductive circuit pattern including via holes is formed by applying electroless plating to the non-resist-formed portions, and such a process is repeated a plurality of times to obtain a multi-layered build-up wiring board by the additive method.

[0003]

In a multilayer printed wiring board manufactured by such a method, the inner-layer conductive circuit formed on the substrate secures close contact with the interlayer resin insulating layer on the conductive circuit. In order to do so, the surface is subjected to a roughening treatment. For example, Japanese Patent Application Laid-Open No. 6-283860 discloses a method in which a copper conductor pattern is coated with a needle-like alloy made of Cu-Ni-P to roughen the conductor surface.

However, in the roughening process of applying a needle-shaped alloy plating made of Cu-Ni-P to a copper conductor pattern, if an opening for a via hole is provided in an interlayer resin insulating layer in a later step, Cu-Ni-P is removed from the opening. The Ni-P needle-like alloy plating layer is exposed. Therefore, when manufacturing a printed wiring board, when the interlayer resin insulation layer is roughened with an acid or an oxidizing agent, or when the wiring board is treated with a soft etching solution,
There has been a problem that the conductor circuit comes into contact with such an acid, an oxidizing agent or a soft etching solution, and the Cu-Ni-P needle-like alloy plating layer and the conductor circuit are dissolved.

[0005] Techniques that can overcome such problems include:
The inventors have previously disclosed in Japanese Patent Application Laid-Open No. 9-130050
A method was proposed in which the surface of a needle-like alloy layer made of -Ni-P was tin-substituted and the roughened layer was covered with a tin layer.

[0006]

However, even with such a coating with a tin layer, rarely, Cu-Ni-
A phenomenon in which the P needle-shaped alloy layer and the conductor circuit were melted was observed. This phenomenon is particularly noticeable in the semi-additive method where the conductor circuit is composed of an electrolytic plating film and an electroless plating film.
The voids were large and caused the connection reliability of the wiring board to deteriorate.

A main object of the present invention is to provide a method of manufacturing a multilayer printed wiring board capable of reliably preventing melting of a Cu-Ni-P needle-like alloy layer or a conductor circuit due to a local battery reaction and suppressing defects such as disconnection. It is to propose.

[0008]

Means for Solving the Problems The present inventors have made intensive studies to realize the above object. As a result, the cause of dissolution of the Cu-Ni-P needle-like alloy layer and the conductor circuit is that the crystallinity of the needle-like alloy made of Cu-Ni-P is low, and the needle-like alloy surface of Cu-Ni-P It is presumed that factors such as an oxide film that hinder the substitution reaction between copper and tin exist. That is, the needle-shaped alloy made of Cu-Ni-P is easily dissolved because of its low crystallinity, and is dissolved by contacting an acid, an oxidizing agent and a soft etching solution to cause a local battery reaction,
In addition, the needle-shaped alloy made of Cu-Ni-P has a factor on the surface thereof such as an oxide film that hinders the substitution reaction between copper and tin, so that the tin substitution becomes insufficient, and the acid, oxidizing agent and It was thought that a local battery reaction was caused by contact with the soft etching solution to cause dissolution. Based on such an estimate,
The inventors formed a roughened layer made of a crystalline alloy on the surface of a conductive circuit, and improved the crystallinity of the roughened layer by heat treatment so that the roughened layer was hardly melted. By removing the oxide film and the like on the surface of the roughened layer by acid treatment, the metal coating layer is more completely formed on the roughened layer surface, and by suppressing the local battery reaction that dissolves the conductor circuit, The inventors have found that the above-mentioned problem can be solved, and have arrived at the present invention.

That is, the gist of the present invention is as follows. (1) In manufacturing a multilayer printed wiring board, a multilayer printed circuit is characterized in that a roughened layer is formed on the surface of a conductor circuit provided on a substrate, a heat treatment is performed, and then an interlayer insulating layer is formed. This is a method for manufacturing a wiring board. (2) After forming a roughened layer on the surface of the conductor circuit provided on the substrate, an interlayer insulating layer is formed, an opening for a via hole is provided in the interlayer insulating layer, and Forming a conductive circuit on the substrate, thereby electrically connecting the conductive circuit on the substrate and the conductive circuit on the interlayer insulating layer via the roughened layer exposed from the opening. The method for manufacturing a multilayer printed wiring board, wherein the roughening layer is subjected to a heat treatment.

[0010] In the manufacturing method according to the above (1) or (2), a roughened layer made of a needle-like alloy of copper, nickel and phosphorus is formed on the surface of the conductor circuit provided on the substrate. preferable. In addition, the heat treatment is performed at 100 to 150 ° C.
For 30 minutes to 3 hours.

(3) In manufacturing a multilayer printed wiring board, after forming a roughened layer on the surface of a conductor circuit provided on a substrate, the roughened layer surface is subjected to an acid treatment, and then the roughened layer surface is formed. Forming a metal coating layer made of a metal or a noble metal containing at least one metal having a higher ionization tendency than copper and not more than titanium, and further forming an interlayer insulating layer. is there. (4) After forming a roughened layer on the surface of the conductor circuit provided on the substrate, an interlayer insulating layer is formed, and an opening for a via hole is provided in the interlayer insulating layer. Forming a conductive circuit on the substrate, thereby electrically connecting the conductive circuit on the substrate and the conductive circuit on the interlayer insulating layer via the roughened layer exposed from the opening. The roughened layer, after acid-treating its surface,
A method for producing a multilayer printed wiring board, characterized by being coated with a metal coating layer made of a metal or a noble metal containing at least one metal having a higher ionization tendency than copper and not more than titanium.

In the manufacturing method according to the above (3) or (4), a roughened layer made of an acicular alloy of copper, nickel and phosphorus is formed on a surface of the conductor circuit provided on the substrate,
It is preferable to form a tin film after the acid treatment. In the acid treatment, it is preferable to use at least one aqueous solution selected from sulfuric acid, nitric acid, borofluoric acid and carboxylic acid.

(5) In manufacturing a multilayer printed wiring board, a roughened layer is formed on the surface of a conductor circuit provided on a substrate, and after heat treatment, the surface of the roughened layer is acid-treated. Next, a metal coating layer made of a metal or a noble metal containing at least one metal having a higher ionization tendency than copper and not more than titanium is formed on the surface of the roughened layer, and an interlayer insulating layer is further formed. This is a method for manufacturing a wiring board. (6) After forming a roughened layer on the surface of the conductor circuit provided on the substrate, an interlayer insulating layer is formed, an opening for a via hole is provided in the interlayer insulating layer, and Forming a conductive circuit on the substrate, thereby electrically connecting the conductive circuit on the substrate and the conductive circuit on the interlayer insulating layer via the roughened layer exposed from the opening. The roughened layer is subjected to a heat treatment, and after the surface thereof is subjected to an acid treatment, is coated with a metal coating layer made of a metal or a noble metal containing at least one metal having a higher ionization tendency than copper and not more than titanium. A method for manufacturing a multilayer printed wiring board.

In the manufacturing method according to the above (5) or (6), a roughened layer made of a needle-like alloy of copper, nickel and phosphorus is formed on a surface of the conductor circuit provided on the substrate,
It is preferable to form a tin film after the acid treatment. In the acid treatment, it is preferable to use at least one aqueous solution selected from sulfuric acid, nitric acid, borofluoric acid and carboxylic acid. Further, the heat treatment is performed by:
The treatment is preferably carried out at a temperature of about 150 ° C. for 30 minutes to 3 hours.

[0015]

According to the production method according to the present invention described in the above (1) and (2), a crystalline roughened layer such as a needle-shaped alloy layer made of copper, nickel and phosphorus is heated. The treatment improves the crystallinity, and the acid, oxidizing agent,
The resistance of the roughened layer to the soft etching solution can be improved. This makes it difficult for the roughened layer to dissolve, thereby suppressing a local battery reaction.

According to the production method of the present invention described in the above (3) and (4), after the surface of the roughened layer is subjected to an acid treatment, a metal coating layer of tin or the like is formed. The coating can be completely covered, hindering the progress of the local battery reaction, and suppressing the dissolution of the roughened layer itself and the conductor circuit.

According to the manufacturing method of the present invention described in the above (5) and (6), since the roughened layer is subjected to the acid treatment after the heat treatment, the oxide film formed on the surface of the roughened layer by the heat treatment is obtained. Can be advantageously removed, and a metal coating layer of tin or the like can be easily formed. As a result, according to this method, both the improvement of the crystallinity of the roughened layer and the complete coverage of the roughened layer can be achieved, which is particularly advantageous in suppressing the dissolution of the roughened layer and the conductor circuit due to the local battery reaction. is there.

In such a method of the present invention, a layer made of an acicular alloy of copper, nickel and phosphorus is most suitable as the roughened layer formed on the surface of the conductor circuit provided on the substrate. The reason is that such a needle-shaped alloy has excellent adhesion to the interlayer resin insulating layer. Here, the composition of a Cu—Ni—P alloy capable of forming an acicular alloy is shown in a ternary triangular diagram (see FIG. 1). As is clear from this triangular diagram, the composition that can form an acicular alloy is (Cu, Ni, P) = (100,
(0, 0), (90, 10, 0) and (90, 0, 10).

Since this needle-shaped alloy is a crystalline alloy, its crystallinity can be improved by heat treatment (so-called annealing). The heat treatment is
The heat treatment is preferably performed at 100 to 150 ° C. for 30 minutes to 3 hours. The reason for this is that if the heat treatment temperature is too low, the effect of annealing is low, while if the heat treatment temperature is too high, oxidation of the copper-nickel-phosphorus alloy proceeds.

The roughened layer made of a needle-like alloy such as copper-nickel-phosphorus is left in the air or heat-treated as described above to form an oxide film on its surface. In the present invention,
Such an oxide film can be removed by an acid treatment. This makes it possible to easily form a metal coating layer of tin or the like on the surface of the roughened layer made of the copper-nickel-phosphorus needle-like alloy by displacement plating or the like.

Therefore, according to the present invention, by subjecting the roughened layer made of the acicular alloy to heat treatment and / or acid treatment, the crystallinity of the acicular alloy can be improved and / or the surface coating of the acicular alloy can be surely performed. Can inhibit the local battery reaction,
The dissolution of the copper-nickel-phosphorus needle-like alloy and the conductor circuit can be suppressed.

In the present invention, the metal coating layer is formed of one metal having an ionization tendency greater than that of copper and equal to or less than titanium.
It is a metal or noble metal layer containing more than one kind. Here, as the metal having an ionization tendency larger than copper and equal to or less than titanium, at least one selected from titanium, aluminum, zinc, iron, indium, thallium, cobalt, nickel, tin, lead, and bismuth is used. Can be. In addition, gold, silver, platinum, and palladium can be used as the noble metal. In particular, the use of tin is advantageous in that a thin layer following the roughened layer can be formed by electroless displacement plating. It is desirable that the thickness of the metal coating layer be 0.1 to 2 μm.

In the present invention, the acid treatment is carried out by dipping in at least one kind of an aqueous acid solution selected from sulfuric acid, nitric acid, borofluoric acid, and carboxylic acid, or by spraying the aqueous acid solution. The concentration of this aqueous acid solution is 1 to 20% by weight for sulfuric acid, and 0.05% for borofluoric acid.
About 1.0 mol%.

In the method of the present invention, a coating layer may be formed between the conductor circuit and the roughened layer. This coating layer is made of nickel,
It is desirable to be made of at least one selected from cobalt or a copper-nickel-phosphorus alloy, and particularly a copper-nickel-phosphorus alloy is optimal. The reason for this is that the coating layer is desirably the same metal as the roughened layer from the viewpoint of preventing a local battery reaction. That is, the copper-nickel-phosphorus alloy is optimal as the coating layer because the copper-nickel-phosphorus needle-like alloy is optimal as the roughened layer.

When a coating layer is formed between the conductor circuit and the roughened layer, the thickness of the roughened layer is preferably 1 to 5 μm, and the thickness of the coating layer is preferably 1 to 10 μm. The reason for this is that if the coating layer is too thin, uncovered portions may be formed on the surface of the conductor circuit, and the conductor circuit may be melted due to local battery reaction. Alternatively, it becomes difficult to maintain insulation between layers. On the other hand, if the roughened layer is too thin, the adhesion to the interlayer resin insulating layer will be poor. Conversely, if the roughened layer is too thick, it will be difficult to maintain insulation between layers or between conductors.

In the present invention, a plating method in which a copper-nickel-phosphorus needle-like alloy layer is formed as a roughening layer on the surface of a conductor circuit, and a method in which the surface of the roughening layer is covered by tin substitution plating will be described. I do. In the present invention,
A substrate provided with a conductor circuit is immersed in an aqueous plating solution containing a complexing agent, a copper compound, a nickel compound, and hypophosphite to form a roughened layer made of a copper-nickel-phosphorus needle-like alloy. Is preferred.

The aqueous plating solution has a copper ion concentration, a nickel ion concentration, a hypophosphite ion concentration, and a complexing agent concentration of 2.2 × 10 ^{-2 to} 4.1 × 10 ^-2 mol / l and 2.2 × 10 ^-2 mol / l, respectively.
10 ^{-3 to} 4.1 x 10 ^-3 mol / l, 0.20 to 0.25 mol / l, 0.01
It is desirable to adjust so as to be about 0.2 mol / l. As the complexing agent, a hydroxycarboxylic acid such as citric acid is preferable. More specific electroless plating solution compositions include copper sulfate 1 to 40 g / l, nickel sulfate 0.1
6.0 g / l, citric acid 10-20 g / l, hypophosphite 10
~ 100 g / l, boric acid 10 ~ 40 g / l, surfactant 0.01 ~
It is desirable to use a plating bath having a liquid composition of 10 g / l.

When the surface of the roughened layer is replaced and coated with tin, tin borofluoride-thiourea or tin chloride-thiourea liquid is used. Thereby, the substitution reaction of Cu-Sn
A Sn metal coating layer of about 0.1 to 2 μm is formed. on the other hand,
When the roughened layer surface is coated with a noble metal, a method such as sputtering or vapor deposition can be adopted.

In the present invention, it is desirable to use an adhesive for electroless plating as the interlayer resin insulating layer covering the conductor circuit. As the adhesive for electroless plating, heat-resistant resin particles that are soluble in a cured acid or oxidizing agent are dispersed in an uncured heat-resistant resin that becomes hardly soluble in an acid or an oxidizing agent by the curing treatment. Is best. The reason for this is that the interlayer resin insulating layer formed using such an adhesive is treated with an acid and an oxidizing agent to dissolve and remove the heat-resistant resin particles, and the roughened surface formed of an octopus-shaped anchor is formed on the surface. Is formed.

In the adhesive for electroless plating, the heat-resistant resin particles particularly subjected to the curing treatment include a heat-resistant resin powder having an average particle diameter of 10 μm or less, and an average particle diameter of 2 μm.
Aggregated particles obtained by aggregating the following heat-resistant resin powder, a mixture of a heat-resistant powder resin powder having an average particle diameter of 2 μm to 10 μm and a heat-resistant resin powder having an average particle diameter of 2 μm or less, having an average particle diameter of 2 to 10 μm Average particle size is 2μm on the surface of heat resistant resin powder
Pseudo particles obtained by adhering at least one of the following heat-resistant resin powder or inorganic powder, having an average particle size of 0.1
It is preferable to use at least one selected from a mixture of a heat-resistant resin powder having a mean particle size of about 0.8 μm and a heat-resistant resin powder having an average particle diameter of more than 0.8 μm and less than 2 μm. This is because they can form more complex anchors.

As the heat-resistant resin, an epoxy resin, a polyimide resin, or a composite of an epoxy resin and a thermoplastic resin can be used. Examples of the thermoplastic resin to be composited include polyether ether sulfone (PES), polyphenylene ether (PPE), and polyphenylene sulfide (P
PES) and the like. Examples of the heat-resistant resin particles that dissolve in an acid or an oxidizing agent include epoxy resin particles (particularly, epoxy resin cured with an amine-based curing agent is preferable) and amino resin particles.

Next, one method of manufacturing a printed wiring board according to the present invention will be described. (1) First, a wiring board having an inner copper pattern formed on the surface of a core board is manufactured. The copper pattern is formed on the core substrate by etching the copper clad laminate, or
An adhesive layer for electroless plating is formed on a substrate such as a glass epoxy substrate, a polyimide substrate, a ceramic substrate, or a metal substrate, and the surface of the adhesive layer is roughened to a roughened surface, which is then subjected to electroless plating. There is a way. Further, if necessary, a roughened layer is formed on the surface of the conductor circuit. As a method of forming the roughened layer, there is an oxidation (blackening) -reduction treatment, a method of etching a copper surface along a grain boundary to form a roughened surface, and the like. Note that a through hole is formed in the core substrate, and the wiring layer on the front surface and the back surface can be electrically connected through the through hole. Further, a resin may be filled between the through hole and the conductor circuit of the core substrate to ensure smoothness. Furthermore, after forming a roughened layer made of a copper-nickel-phosphorus needle-like alloy on the conductor circuit surface of the core substrate and the land surface of the through hole as described above, heat treatment and / or acid treatment is performed. , Tin or the like to form a metal coating layer.

(2) Next, an interlayer resin insulating layer is formed on the wiring board manufactured in the above (1). In particular, in the present invention, it is desirable to use the above-mentioned adhesive for electroless plating as an interlayer resin insulating material.

(3) After the formed adhesive layer for electroless plating is dried, openings for forming via holes are provided as necessary. In the case of a photosensitive resin, it is exposed and developed and then thermally cured. In the case of a thermosetting resin, it is thermally cured and then subjected to laser processing, so that an opening for forming a via hole is formed in the adhesive layer. Section is provided.

(4) Next, the epoxy resin particles present on the surface of the cured adhesive layer are dissolved and removed with an acid or an oxidizing agent, and the surface of the adhesive layer is roughened. Here, examples of the acid include phosphoric acid, hydrochloric acid, sulfuric acid, and organic acids such as formic acid and acetic acid, and it is particularly preferable to use an organic acid. This is because when the roughening treatment is performed, the metal conductor layer exposed from the via hole is hardly corroded. On the other hand, it is desirable to use chromic acid and permanganate (such as potassium permanganate) as the oxidizing agent.

(5) Next, a catalyst nucleus is applied to the wiring board whose surface of the adhesive layer has been roughened. It is desirable to use a noble metal ion or a noble metal colloid for providing the catalyst nucleus, and generally, palladium chloride or a palladium colloid is used. Note that it is desirable to perform a heat treatment to fix the catalyst core. Palladium is preferred as such a catalyst core.

(6) Next, electroless plating is performed on the surface of the adhesive layer for electroless plating, and an electroless plating film is formed on the entire roughened surface. The thickness of the electroless plating film is 0.5 to 5 μm. The electroless plating film is desirably subjected to a heat treatment at 50 to 150 ° C. for 30 minutes to 4 hours. This is for improving the resistance to acids and oxidizing agents.

(7) Next, a plating resist is formed on the electroless plating film. As the plating resist composition, it is particularly preferable to use a composition comprising an acrylate of a cresol novolak type epoxy resin or an acrylate of a phenol novolak type epoxy resin and an imidazole curing agent, and other commercially available products can also be used.

(8) Next, the plating resist non-formed portion is subjected to electrolytic plating with a thickness of 5 to 20 μm to form a conductor circuit and a via hole. Before applying electrolytic plating,
In order to remove the oxide film on the surface, the surface may be treated with an acid such as an organic acid, hydrochloric acid or sulfuric acid. Such a surface treatment may be performed before or after forming the plating resist. Here, it is desirable to use copper plating as the electrolytic plating. Preferably, the electrolytic plating film is subjected to a heat treatment at 50 to 150 ° C. for 30 minutes to 7 hours. This is for improving the resistance to acids and oxidizing agents.

(9) After removing the plating resist, the electroless plating film is dissolved and removed with a mixed solution of sulfuric acid and hydrogen peroxide or an etching solution such as sodium persulfate and ammonium persulfate to form an independent conductor circuit. I do. Before etching and removing the electroless plating film, an organic acid, hydrochloric acid,
It is preferable to remove the oxide film on the plating film surface with an acid such as sulfuric acid. This is because the etching rate is changed due to the presence of the oxide film, and an etching residue occurs.

(10) Next, after forming a roughened layer made of a copper-nickel-phosphorus needle-like alloy on the surface of the conductor circuit formed in the above (9), as described above, heat treatment and / or The metal coating layer is formed by performing an acid treatment or performing displacement plating with tin or the like. (11) Then, an adhesive layer for electroless plating is formed on the substrate as an interlayer resin insulating layer. (12) Further, the above steps (3) to (9) are repeated to provide a further upper layer conductive circuit, thereby obtaining a six-layer double-sided multilayer printed wiring board having three layers on one side.

The above description is an example formed by a method called a semi-active method. In the present invention, after roughening an adhesive layer for electroless plating, a catalyst nucleus is provided, a plating resist is provided, The present invention can be applied to a so-called full additive method in which a conductor circuit is formed by performing electroless plating.

(13) Next, a solder resist composition is applied to the multilayer wiring board obtained in the above (12), and then the coating film is dried. By exposing and developing the mask film, a solder resist having an opening exposing a pad portion of the conductor circuit is formed. Here, the opening diameter of the opening can be larger than the diameter of the pad,
The pad may be completely exposed. Conversely, the diameter of the opening can be smaller than the diameter of the pad, and the periphery of the pad can be covered with a solder resist. In this case, the pad can be suppressed by the solder resist, and peeling of the pad can be prevented.

(14) Next, a “nickel-gold” metal layer is formed on the pad portion exposed from the opening. (15) Then, a solder body is supplied onto the pad portion exposed from the opening, and a printed wiring board having the solder body is obtained. Hereinafter, description will be made based on embodiments.

[0045]

【Example】

Example 1 A. Preparation of Adhesive A for Electroless Plating (for Upper Layer) 35 parts by weight of a resin solution prepared by dissolving a 25% acrylated cresol novolak type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., molecular weight: 2500) in DMDG at a concentration of 80 wt%; Parts, defoamer (manufactured by San Nopco, S-65) 0.5 parts by weight, NMP 3.6
The parts by weight were mixed with stirring. . 12 parts by weight of polyethersulfone (PES), 7.2 parts by weight of an average particle diameter of 1.0 μm of epoxy resin particles (manufactured by Sanyo Chemical Industries, polymer pole), and 3 parts by weight of an average particle diameter of 0.5 μm.
After mixing 09 parts by weight, 30 parts by weight of NMP was further added, and the mixture was stirred and mixed by a bead mill. . 2 parts by weight of an imidazole curing agent (2E4MZ-CN, manufactured by Shikoku Chemicals), a photoinitiator (Irgacure I-, manufactured by Ciba-Geigy)
907) 2 parts by weight, photosensitizer (DETX-S, manufactured by Nippon Kayaku) 0.2
Parts by weight and 1.5 parts by weight of NMP were mixed with stirring. These were mixed to prepare an adhesive for electroless plating.

B. Preparation of Adhesive B for Electroless Plating (for Lower Layer) 35 parts by weight of a resin solution prepared by dissolving a 25% acrylate of cresol novolac type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., molecular weight: 2500) at a concentration of 80 wt% in DMDG, and 4 parts by weight of a photosensitive monomer (Alonix M315 manufactured by Toa Gosei) Parts, 0.5 parts by weight of an antifoaming agent (manufactured by San Nopco, S-65) and 3.6 parts by weight of NMP were mixed with stirring. . After mixing 12 parts by weight of polyether sulfone (PES) and 14.49 parts by weight of an epoxy resin particle (manufactured by Sanyo Chemical Industries, polymer pole) having an average particle size of 0.5 μm, further add 30 parts by weight of NMP and stir with a bead mill. Mixed. . 2 parts by weight of an imidazole curing agent (2E4MZ-CN, manufactured by Shikoku Chemicals), a photoinitiator (Irgacure I-, manufactured by Ciba-Geigy)
907) 2 parts by weight, photosensitizer (DETX-S, manufactured by Nippon Kayaku) 0.2
Parts by weight and 1.5 parts by weight of NMP were mixed with stirring. These were mixed to prepare an adhesive for electroless plating used as a lower insulating layer constituting a two-layer interlayer resin insulating layer.

C. Preparation of resin filler 100 parts by weight of bisphenol F type epoxy monomer (manufactured by Yuka Shell, molecular weight 310, YL983U), Si coated with a silane coupling agent on the surface and having an average particle size of 1.6 μm
O ₂ spherical particles (manufactured by Admatech, CRS 1101-CE, where the maximum particle size is not more than the thickness (15 μm) of the inner layer copper pattern described later) 170 parts by weight, leveling agent (manufactured by San Nopco, Perenol S4) 1.5 The weight of the mixture is kneaded with three rolls and the viscosity of the mixture is 45,000 ~ at 23 ± 1 ° C.
Adjusted to 49,000cps. . Imidazole curing agent (2E4MZ-CN, manufactured by Shikoku Chemicals) 6.5
Parts by weight. These were mixed to prepare a resin filler 10.

D. Manufacturing method of printed wiring board (1) 18 μm on both sides of substrate 1 made of glass epoxy resin or BT (bismaleimide triazine) resin having a thickness of 1 mm
A copper-clad laminate on which m copper foils 8 were laminated was used as a starting material (see FIG. 2). First, the copper clad laminate is drilled, subjected to an electroless plating treatment to form a through hole 9, and further, the copper foil 8 is etched in a pattern according to a conventional method to form an inner layer on both surfaces of the substrate 1. Copper pattern 4
Was formed.

(2) The substrate on which the inner layer copper pattern 4 and the through hole 9 were formed was washed with water and dried. Then, NaOH (10 g / l) and NaClO ₂ (40 g /
l), Na ₃ PO ₄ (6 g / l), NaOH (10 g
/ L) and a roughened layer 11 was provided on the entire surface of the inner layer copper pattern 4 and the through holes 9 by oxidation-reduction treatment using NaBH ₄ (6 g / l) (see FIG. 3).

(3) The resin filler 10 is applied to one surface of the substrate by using a roll coater to fill the space between the conductor circuits 4 or into the through holes 9 and dried at 70 ° C. for 20 minutes. In the same way, the resin filler 10 is filled between the conductor circuits 4 or in the through holes 9 at 70 ° C., 20 ° C.
It was dried by heating for minutes (see FIG. 4).

(4) One surface of the substrate after the treatment of (3) is subjected to belt sanding using # 600 belt abrasive paper (manufactured by Sankyo Rikagaku Co., Ltd.) to form the surface of the inner layer copper pattern 4 and the through holes 9. Polishing was performed so that the resin filler 10 did not remain on the land surface, and then buffing was performed to remove scratches due to the belt sander polishing. Such a series of polishing was similarly performed on the other surface of the substrate. Next, a heat treatment was performed at 100 ° C. for 1 hour, at 120 ° C. for 3 hours, at 150 ° C. for 1 hour, and at 180 ° C. for 7 hours to cure the resin filler 10 (see FIG. 5).

In this manner, the surface layer of the resin filler 10 filled in the through holes 9 and the like and the roughened layer 11 on the upper surface of the inner conductor circuit 4 are removed to smooth both surfaces of the substrate.
A wiring board is firmly adhered to the side surface of the inner conductor circuit 4 via the roughened layer 11 and the inner wall surface of the through hole 9 is tightly adhered to the resin filler 10 via the roughened layer 11. Obtained. That is, by this step, the surface of the resin filler 10 and the surface of the inner layer copper pattern 4 become flush with each other. Here, the Tg point of the filled cured resin is 155.6 ° C., and the coefficient of linear thermal expansion is 44.5 × 10 ⁻⁶ /
° C.

(5) On the surface of the land of the inner layer conductor circuit 4 and the through hole 9 exposed in the process of (4), a thickness of 5 μm
m-Cu-Ni-P alloy coating layer, 2 μm thick Cu-
A roughened layer made of a Ni-P needle-shaped alloy and a Sn metal coating layer having a thickness of 0.3 μm covering the roughened layer surface were provided (see FIG. 6, but the Sn layer is not shown). The formation method is as follows. That is, the substrate was acid-degreased and soft-etched, and then treated with a catalyst solution comprising palladium chloride and an organic acid to provide a Pd catalyst. After activating this catalyst, copper sulfate 8 g / l, nickel sulfate 0.6g /
l, citric acid 15 g / l, sodium hypophosphite 29 g /
1, boric acid 31 g / l, surfactant 0.1 g / l, pH = 9
The substrate was immersed in an electroless plating bath made of, and a roughened layer made of a needle-shaped alloy of Cu-Ni-P was deposited. Further, the substrate was subjected to a heat treatment at 100 ° C. for 30 minutes, 120 ° C. for 30 minutes, and 150 ° C. for 2 hours.
After treatment with an aqueous solution of borofluoric acid, tin borofluoride is added.
1 mol / l, thiourea 1.0 mol / l, temperature 50 ° C, pH = 1.2
Cu-Sn substitution reaction under the following conditions, the thickness of the surface of the roughened layer 11
A 0.3 μm Sn metal coating layer was provided (the Sn layer is not shown).

(6) An adhesive for electroless plating of B (viscosity: 1.5 Pa · s) is applied to both surfaces of the substrate of (5) by a roll coater, and is left in a horizontal state for 20 minutes. (Prebaking) for 30 minutes to form an insulating agent layer 2a. Further, an adhesive for electroless plating (A) (viscosity: 7 Pa · s) is applied on the insulating layer 2a using a roll coater, and left for 20 minutes in a horizontal state, and then dried at 60 ° C. for 30 minutes. Then, an adhesive layer 2b was formed (see FIG. 7).

(7) The insulating layer 2a and the adhesive layer in the above (6)
A photomask film on which a black circle of 85 μmφ was printed was brought into close contact with both surfaces of the substrate on which 2b was formed, and was exposed at 500 mJ / cm ² using an ultra-high pressure mercury lamp. This was spray-developed with a DMDG solution to form an 85 μmφ via hole opening in the adhesive layer. Further, the substrate is exposed to 3000 mJ / cm ² using an ultra-high pressure mercury lamp, and is subjected to a heat treatment (post-baking) at 100 ° C. for 1 hour and then at 150 ° C. for 5 hours, so that dimensional accuracy equivalent to a photomask film is obtained. An interlayer resin insulating layer (adhesive layer) 2 having a two-layer structure having a thickness of 35 μm and having an excellent opening (opening 6 for forming a via hole) was formed. The tin plating layer (not shown) was partially exposed in the opening serving as the via hole.

(8) The substrate subjected to the treatment of (7) is
g / l of chromic acid at 70 ° C. for 15 minutes to dissolve and remove the resin particles on the surface of the interlayer resin insulating layer 2, thereby making the surface of the interlayer resin insulating layer 2 rough (3 μm in depth). ), And then immersed in a neutralizing solution (manufactured by Shipley) and washed with water (see FIG. 9). Further, by applying a palladium catalyst (manufactured by Atotech) to the surface of the substrate subjected to the surface roughening treatment, a catalyst nucleus was attached to the surface of the interlayer resin insulating layer 2 and the inner wall surface of the via hole opening 6.

(9) The substrate was immersed in an electroless copper plating bath having the following composition to form an electroless copper plating film 12 having a thickness of 0.6 μm on the entire rough surface (see FIG. 10). Further, this electroless plating film 12 is treated at 50 ° C. for 1 hour, at 100 ° C. for 30 minutes, and at 120 ° C.
For 2 minutes at 150 ° C. [Electroless plating solution] EDTA 150 g / l Copper sulfate 20 g / l HCHO 30 ml / l NaOH 40 g / l α, α'-bipyridyl 80 mg / l PEG 0.1 g / l [Electroless plating conditions] 70 ° C. 30 minutes at liquid temperature

(10) The electroless copper plating film formed in the above (9)
A commercially available photosensitive dry film was stuck on 12 and a mask was placed thereon, exposed at 100 mJ / cm ² , developed with 0.8% sodium carbonate, and provided with a plating resist 3 having a thickness of 15 μm (FIG. 11). reference).

(11) Then, after the surface of the electroless plating film is treated with a 10% sulfuric acid aqueous solution, the portion where the resist is not formed is subjected to electrolytic copper plating under the following conditions to obtain a 15 μm-thick electrolytic copper plating film.
13 was formed (see FIG. 12). Furthermore, this electrolytic plating film
13 at 50 ° C for 30 minutes, 80 ° C for 30 minutes, 100 ° C for 30 minutes, 120 ° C
For 30 minutes and at 150 ° C. for 5 hours. [Electroplating solution] Sulfuric acid 180 g / l Copper sulfate 80 g / l Additive (captoside GL, manufactured by Atotech Japan) 1 ml / l [Electroplating conditions] Current density 1 A / dm ² hours 30 minutes Temperature Room temperature

(12) After peeling off the plating resist 3 with 5% KOH, the surface is treated with a 10% sulfuric acid aqueous solution, and the electroless plating film 12 under the plating resist 3 is further treated with a mixed solution of sulfuric acid and hydrogen peroxide. An etching treatment was carried out to dissolve and remove, thereby forming a conductor circuit (including via holes) 5 having a thickness of 18 μm and comprising an electroless copper plating film 12 and an electrolytic copper plating film 13. Furthermore, the surface of the adhesive layer for electroless plating between the conductor circuits (located at the portion where no conductor circuit is formed) is immersed in 800 g / l chromic acid at 70 ° C. for 3 minutes, and the surface of the adhesive layer is etched by 1 μm. The remaining palladium catalyst was removed (see FIG. 13).

(13) On the substrate on which the conductor circuit 5 is formed,
Perform the same treatment as in (5), and apply a thickness of 3μ
m-Cu-Ni-P non-acicular alloy coating layer, thickness 5μ
A roughened layer made of a m-Cu-Ni-P needle-shaped alloy and a Sn metal coating layer having a thickness of 0.3 µm covering the roughened layer surface were provided (see Fig. 14).

(14) By repeating the above steps (6) to (13), a conductor circuit of a further upper layer was formed. However, Sn substitution was not performed (see FIGS. 15 to 20).

(15) On the other hand, 60% by weight dissolved in DMDG
Cresol novolak epoxy resin (Nippon Kayaku)
46.67 g of a photosensitizing oligomer (molecular weight 4000) obtained by acrylizing 50% of the epoxy groups of epoxy resin, 15.0 g of an 80 wt% bisphenol A type epoxy resin (made by Yuka Shell, Epicoat 1001) dissolved in methyl ethyl ketone, imidazole curing 1.6 g of an agent (2E4MZ-CN, manufactured by Shikoku Chemicals Co., Ltd.) and a polyacrylic monomer (R604, manufactured by Nippon Kayaku, a photosensitive monomer)
3 g), 1.5 g of polyvalent acrylic monomer (Kyoeisha Chemical, DPE6A), and a dispersion defoaming agent (San Nopco,
S-65) of 0.71 g, and 2 g of benzophenone (Kanto Chemical) as a photoinitiator was added to the mixture.
0.2 of Michler's ketone (Kanto Chemical) as photosensitizer
g was added to obtain a solder resist composition whose viscosity was adjusted to 2.0 Pa · s at 25 ° C. The viscosity was measured using a B-type viscometer (Tokyo Keiki, DVL-B type) at 60 rpm and the rotor No.
In the case of 4, 6 rpm, the rotor No. 3 was used.

(16) The multilayer wiring board obtained in the above (14) is
The solder resist composition was applied in a thickness of 20 μm. Next, after performing a drying process at 70 ° C. for 20 minutes and a temperature of 70 ° C. for 30 minutes, a photomask film on which a circular pattern is drawn is placed in close contact with the substrate, exposed to ultraviolet light of 1000 mJ / cm ² , and developed using DMTG. Processed. And at 80 ° C for 1 hour,
Heat treatment was performed at 100 ° C for 1 hour, 120 ° C for 1 hour, and 150 ° C for 3 hours, and the pad was opened (opening diameter 200μ).
m) A solder resist layer (20 μm thick) 14 was formed.

(17) Next, the substrate on which the solder resist layer 14 has been formed is subjected to a pH of 30 g / l of nickel chloride, 10 g / l of sodium hypophosphite and 10 g / l of sodium citrate.
= 5 for 20 minutes to form a nickel plating layer 15 having a thickness of 5 μm at the opening. Further, the substrate was placed on an electroless gold plating solution comprising 2 g / l of potassium gold cyanide, 75 g / l of ammonium chloride, 50 g / l of sodium citrate, and 10 g / l of sodium hypophosphite at 93 ° C. for 23 seconds. By dipping, a gold plating layer 16 having a thickness of 0.03 μm was formed on the nickel plating layer 15.

(18) A solder paste is printed in the opening of the solder resist layer 14 and reflowed at 200 ° C. to form a solder bump (solder body) 17, and the multilayer printed wiring board having the solder bump 17 is formed. Was manufactured (Figure
21).

Example 2 Same as Example 1, except that titanium, aluminum, zinc, iron, indium, thallium, cobalt, nickel were used instead of tin in (5) and (13) of Example 1. , Lead, bismuth, gold and silver layers were formed.

The titanium, aluminum, zinc, iron, indium, thallium, bismuth, gold, and silver layers were formed by sputtering, and the thickness was 0.5 μm. Cobalt, nickel and lead are formed by plating.
μm.

(Comparative Example 1) A multilayer printed wiring board having solder bumps was manufactured in the same manner as in the example except that the acid treatment was not performed in the processes (5) and (13) of the example. .

(Comparative Example 2) As in Example 1, except that no heat treatment was performed in the processes (5) and (13) of Example 1.

With respect to the multilayer printed wiring boards manufactured in Examples and Comparative Examples, the cross section of the surface portion of the conductor circuit was observed with an optical microscope and a scanning electron microscope, and the presence or absence of dissolution of the conductor circuit was confirmed. Regarding the multilayer printed wiring boards of Examples 1 and 2, regarding the large dissolution of the conductor circuit, the coating layer made of the non-acicular alloy of Cu-Ni-P, and the roughened layer made of the acicular alloy of Cu-Ni-P, Little was observed. On the other hand, in the multilayer printed wiring boards of Comparative Examples 1 and 2, partial dissolution of the conductor circuit was observed.

[0072]

As described above, according to the present invention, it is possible to reliably prevent the conductor circuit from melting due to a local battery reaction, and to improve the connection reliability between the inner conductor circuit and the via hole, thereby improving the connection reliability. A wiring board can be obtained.

[Brief description of the drawings]

FIG. 1 is a triangular diagram showing the composition of a Cu—Ni—P alloy.

FIG. 2 is a diagram showing each manufacturing process of the multilayer printed wiring board according to the present invention.

FIG. 3 is a view showing each manufacturing process of the multilayer printed wiring board according to the present invention.

FIG. 4 is a view showing each manufacturing process of the multilayer printed wiring board according to the present invention.

FIG. 5 is a view showing each manufacturing process of the multilayer printed wiring board according to the present invention.

FIG. 6 is a diagram showing each manufacturing process of the multilayer printed wiring board according to the present invention.

FIG. 7 is a diagram showing each manufacturing process of the multilayer printed wiring board according to the present invention.

FIG. 8 is a diagram showing each manufacturing process of the multilayer printed wiring board according to the present invention.

FIG. 9 is a diagram showing each manufacturing process of the multilayer printed wiring board according to the present invention.

FIG. 10 is a diagram showing each manufacturing process of the multilayer printed wiring board according to the present invention.

FIG. 11 is a diagram showing each manufacturing process of the multilayer printed wiring board according to the present invention.

FIG. 12 is a diagram showing each manufacturing process of the multilayer printed wiring board according to the present invention.

FIG. 13 is a diagram showing each manufacturing process of the multilayer printed wiring board according to the present invention.

FIG. 14 is a diagram showing each manufacturing process of the multilayer printed wiring board according to the present invention.

FIG. 15 is a diagram showing each manufacturing process of the multilayer printed wiring board according to the present invention.

FIG. 16 is a diagram showing each manufacturing process of the multilayer printed wiring board according to the present invention.

FIG. 17 is a diagram illustrating each manufacturing process of the multilayer printed wiring board according to the present invention.

FIG. 18 is a diagram illustrating each manufacturing process of the multilayer printed wiring board according to the present invention.

FIG. 19 is a diagram illustrating each manufacturing process of the multilayer printed wiring board according to the present invention.

FIG. 20 is a diagram showing each manufacturing process of the multilayer printed wiring board according to the present invention.

FIG. 21 is a diagram illustrating each manufacturing process of the multilayer printed wiring board according to the present invention.

[Explanation of symbols]

 Reference Signs List 1 substrate 2 interlayer resin insulating layer (adhesive layer for electroless plating) 2a insulating layer (lower adhesive layer for electroless plating) 2b adhesive layer (upper adhesive layer for electroless plating) 3 plating resist 4 Inner layer conductor circuit (Inner layer copper pattern) 5 Outer layer conductor circuit (Outer layer copper pattern) 6 Via hole opening 7 Via hole 8 Copper foil 9 Through hole 10 Resin filler 11 Roughening layer 110 Coating layer 12 Electroless plating film (Electroless plating) Copper plating film) 13 Electrolytic plating film (electrolytic copper plating film) 14 Solder resist layer 15 Nickel plating layer 16 Gold plating layer 17 Solder bump (solder)

Claims (13)

[Claims] In manufacturing a multilayer printed wiring board, a roughened layer is formed on a surface of a conductor circuit provided on a substrate, and after heat treatment, an interlayer insulating layer is formed. A method for manufacturing a multilayer printed wiring board. 2. After forming a roughened layer on the surface of a conductor circuit provided on a substrate, an interlayer insulating layer is formed, and an opening for a via hole is provided in the interlayer insulating layer. Production of a multilayer printed wiring board for electrically connecting a conductive circuit on a substrate and a conductive circuit on an interlayer insulating layer via a roughened layer exposed from the opening by forming a conductive circuit on the layer In the method, the roughening layer is subjected to a heat treatment. 3. A surface of a conductor circuit provided on a substrate,
3. The method according to claim 1, wherein a roughened layer made of a needle-shaped alloy of copper, nickel and phosphorus is formed. 4. The heat treatment is performed at 100 to 150 ° C. for 30 minutes or more.
The method according to any one of claims 1 to 3, wherein the treatment is performed for 3 hours. 5. When manufacturing a multilayer printed wiring board, after forming a roughened layer on the surface of a conductor circuit provided on a substrate, the surface of the roughened layer is subjected to an acid treatment, and then the surface of the roughened layer is formed. A method for producing a multilayer printed wiring board, comprising: forming a metal coating layer made of a metal or a noble metal containing at least one kind of metal whose ionization tendency is larger than copper and not more than titanium, and further forming an interlayer insulating layer. 6. After forming a roughened layer on the surface of a conductor circuit provided on a substrate, an interlayer insulating layer is formed, and an opening for a via hole is provided in the interlayer insulating layer. Production of a multilayer printed wiring board for electrically connecting a conductive circuit on a substrate and a conductive circuit on an interlayer insulating layer via a roughened layer exposed from the opening by forming a conductive circuit on the layer In the method, after the surface of the roughened layer is subjected to an acid treatment, the surface is coated with a metal coating layer made of a metal or a noble metal containing one or more metals having a tendency to ionize greater than copper and equal to or less than titanium. Manufacturing method of a multilayer printed wiring board. 7. A surface of a conductor circuit provided on a substrate,
The method according to claim 5, wherein a roughened layer made of a needle-shaped alloy of copper, nickel and phosphorus is formed, and a tin film is formed after the acid treatment. 8. The acid treatment according to claim 5, wherein at least one kind of aqueous solution selected from sulfuric acid, nitric acid, borofluoric acid and carboxylic acid is used.
The production method according to any one of the above. 9. When manufacturing a multilayer printed wiring board, after forming a roughened layer on a surface of a conductor circuit provided on a substrate, performing a heat treatment, the surface of the roughened layer is subjected to an acid treatment, Forming a metal coating layer made of a metal or a noble metal containing at least one metal having a higher ionization tendency than copper and not more than titanium on the surface of the roughened layer, and further forming an interlayer insulating layer; Plate manufacturing method. 10. After forming a roughened layer on a surface of a conductor circuit provided on a substrate, an interlayer insulating layer is formed, and an opening for a via hole is provided in the interlayer insulating layer to form the interlayer insulating layer. Production of a multilayer printed wiring board for electrically connecting a conductive circuit on a substrate and a conductive circuit on an interlayer insulating layer via a roughened layer exposed from the opening by forming a conductive circuit on the layer In the method, the roughened layer is a metal coating layer made of a metal or a noble metal containing at least one metal having a tendency to ionize greater than copper and equal to or less than titanium after being subjected to a heat treatment and acid-treating the surface thereof. A method for producing a multilayer printed wiring board, characterized by being coated. 11. The surface of a conductor circuit provided on a substrate,
11. The method according to claim 9, wherein a roughened layer made of a needle-shaped alloy of copper, nickel and phosphorus is formed, and a tin film is formed after acid treatment. 12. The method according to claim 9, wherein the acid treatment uses at least one aqueous solution selected from among sulfuric acid, nitric acid, borofluoric acid and carboxylic acid.
The production method according to any one of the above. 13. The heat treatment is performed at 100 to 150 ° C. for 30 minutes or more.
The method for producing a multilayer printed wiring board according to any one of claims 9 to 12, wherein the treatment is performed for 3 hours.