JP2001144446A - Method for producing multilayer printed wiring board and multilayer printed wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a multilayer printed wiring board in which reliability of connection and electrical connectivity with a via hole made above can be ensured sufficiently even when a coating layer is formed on a roughened surface or a roughened layer formed on a conductor circuit. SOLUTION: A conductor circuit 4 is formed and subjected to roughening thus forming a roughened surface or a roughened layer 11 on the conductor circuit. A metal coating layer is formed on the roughened surface or the roughened layer 11 and the conductor circuit having the coating layer is further coated with an interlayer resin insulation layer 2 before an opening for via hole 7 is made. The process is repeated and a conductor circuit having a plurality of layers sandwiching the interlayer resin insulation layers is formed on an insulating substrate 1. In such a method for producing a multilayer printed wiring board, the coating layer formed on the roughened surface or the roughened layer exposed from the opening for via hole is removed at least partially after the opening for via hole is made in the interlayer resin insulation layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[Detailed description of the invention]

[0002]

2. Description of the Related Art In recent years, a so-called build-up multilayer wiring board has attracted attention due to a demand for higher density of the multilayer wiring board. This build-up multilayer wiring board, for example,
It is manufactured by a method as disclosed in Japanese Patent Publication No. 55555/1992. That is, an adhesive for electroless plating made of a photosensitive resin is applied on the core substrate on which the lower conductive circuit is formed, and then dried and exposed and developed to form an interlayer resin having an opening for a via hole. An insulating layer is formed. Next, after the surface of the interlayer resin insulating layer is roughened by a treatment with an oxidizing agent or the like, the photosensitive resin layer is exposed,
A plating resist is provided by performing a development process, and thereafter, a portion where the plating resist is not formed is subjected to electroless plating or the like to form a conductive circuit pattern including via holes. By repeating such a process a plurality of times, a multilayered build-up wiring board is manufactured.

[0003] In such a build-up multilayer wiring board, as disclosed in Japanese Patent Application Laid-Open No. 6-283860, for improving the adhesion between the conductive circuit and the interlayer resin insulating layer, Cu is formed on the conductive circuit. Forming a needle-shaped or porous roughened layer made of an Ni-P alloy;

Thereafter, acid cleaning of the substrate in a post-process,
The roughened layer formed on the conductor circuit is further coated with a metal such as Sn to prevent the surface of the conductor circuit from being dissolved when the surface of the interlayer resin insulation layer having the via hole opening is treated with chromic acid or the like. I do.

[0005]

However, when a via hole is formed on a conductor circuit having a coating layer of a metal such as Sn, the metal forming the coating layer and the metal forming the via hole are of different types. Since the metal is used, the electric transmission speed of each metal is different, and a signal delay or a signal error may occur in the covering layer.

[0006] In addition, when a metal forming the coating layer and a metal forming the via hole have different thermal expansion coefficients during heating or heat cycle, stress is generated. The present inventors have found a new fact that a contact portion between a via hole and a conductor circuit thereunder may be peeled off, thereby lowering connection reliability and electrical connectivity of the via hole.

SUMMARY OF THE INVENTION An object of the present invention is to provide a semiconductor device having a roughened surface formed on a conductor circuit or a coating layer formed on a roughened layer, which has a high reliability in connection with via holes formed on the roughened surface and a roughened layer. An object of the present invention is to provide a method for manufacturing a multilayer printed wiring board capable of sufficiently securing connectivity, and a multilayer printed wiring board manufactured by the manufacturing method.

[0008]

Means for Solving the Problems In view of the above problems, the present inventor has conducted intensive studies to achieve the above object. As a result, the adhesion between the coating layer such as Sn on the conductor circuit and the via hole is not so strong. , During heating or heat cycle, the occurrence of peeling between the via hole and the conductor circuit was determined,
It has been found that the above problem can be solved by removing the coating layer in the via hole portion, and the present invention has been completed which has the following contents as the essential constitution.

That is, according to the method of manufacturing a multilayer printed wiring board of the present invention, a roughened surface or a roughened layer is formed on a conductive circuit by forming a roughened surface after forming a conductive circuit. Forming a coating layer made of metal on the surface or the roughened layer, further covering the conductive circuit having the coating layer with an interlayer resin insulating layer, and then forming a via hole opening on the insulating substrate by repeating the process. In the method for manufacturing a multilayer printed wiring board for forming a conductor circuit composed of a plurality of layers sandwiching an interlayer resin insulating layer, a via hole opening is formed in the interlayer resin insulating layer, and then the via hole opening is exposed from the via hole opening. It is characterized in that at least a part of the roughened surface or the coating layer on the roughened layer is removed.

[0010] In the method for manufacturing a multilayer printed wiring board, the coating layer formed on the roughened surface or the roughened layer may include:
It is desirable to use a metal or a noble metal having a higher ionization tendency than copper and not more than titanium.

In the above method for producing a multilayer printed wiring board, an alkaline solution containing 1 to 40% by weight of an acid and an oxidizing agent, or a mixed solution of 1 to 40% by weight of an acid and a peroxide is used. It is desirable to remove the roughened surface or the coating layer of the roughened layer exposed from the via hole opening by the etching treatment used. The acid is desirably at least one selected from the group consisting of hydrochloric acid, nitric acid, sulfuric acid, hydrofluoric acid, phosphoric acid, and formic acid.

The multilayer printed wiring board of the present invention has a roughened surface, and an interlayer resin insulating layer is formed on a substrate on which a conductive circuit having a metal coating layer is formed on the roughened surface. A via hole opening is formed in the interlayer resin insulating layer; and a conductor layer is formed in the via hole opening to form a via hole. The circuit part is
At least a part of the metal coating layer is removed, and the roughened surface is directly connected to the conductor layer.

In the multilayer printed wiring board as well, the metal coating layer is desirably made of a metal or a noble metal having an ionization tendency larger than copper and equal to or lower than titanium.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION In the method for manufacturing a multilayer printed wiring board according to the present invention, a roughened surface or a roughened layer is formed on a conductive circuit by forming a roughened surface after forming a conductive circuit. Forming a coating layer made of metal on the roughened surface or the roughened layer,
Further, by repeating the step of forming the via hole opening after covering the conductor circuit having the coating layer with the interlayer resin insulation layer, a conductor circuit including a plurality of layers with the interlayer resin insulation layer interposed therebetween is formed on the insulating substrate. In the method for manufacturing a multilayer printed wiring board, after forming a via hole opening in the interlayer resin insulating layer, at least a part of the coating layer on the roughened surface or the roughened layer exposed from the via hole opening. It is characterized by removal.

According to the structure of the present invention, after forming the via hole opening in the interlayer resin insulating layer, at least a part of the coating layer exposed from the via hole opening is removed, so that the via hole is formed thereon. When formed, the adhesion between the roughened surface or the roughened layer and the via hole and the electrical connectivity are improved.

The improvement in the adhesion is usually caused by
Since a different type of metal is used for the coating layer than the via hole, the adhesion between the two is not so high. On the other hand, the lower conductive circuit (roughened layer) and the via hole usually have the same type of metal. This is because, by using, the adhesion can be improved by bringing the two into direct contact.

Further, the lower conductor circuit and the via hole form:
Since the same metal is used, the electric transmission speed of both is the same, and the electric delay and signal error that occur when connecting the lower conductor circuit and the via hole via the coating layer are reduced by the lower conductor. It does not occur between the circuit and the via hole. Further, even during heating or under heat cycle conditions, there is no difference in thermal expansion coefficient between the lower conductor circuit and the via hole, so that no stress is generated and no problem such as peeling of the via hole occurs.

Therefore, according to the above method, a via hole having excellent adhesion to the conductor circuit can be formed on the conductor circuit, and the connection reliability between the via hole and the conductor circuit can be improved.
A multilayer printed wiring board with sufficient electrical connectivity can be manufactured.

1 (a), 2 (a) and 3 (a)
1 is a cross-sectional view showing a part of a multilayer printed wiring board manufactured by using the manufacturing method of the present invention.
(B) and FIG. 3 (b) are conceptual diagrams showing the shape inside the via hole opening of the multilayer printed wiring board manufactured by using the manufacturing method of the present invention. In the drawings, a roughened surface or a roughened layer formed on the side surface of the conductor circuit and the surface of the interlayer resin insulating layer is omitted.

In the method for manufacturing a multilayer printed wiring board according to the present invention, the method for forming a roughened surface or a roughened layer on the conductor circuit 4 is not particularly limited, and may include etching, blackening reduction, plating, and the like. Processing and the like. In the drawing, a structure in which the roughened layer 11 is formed on the conductor circuit 4 is shown. As the etching treatment method,
For example, a method in which an etching solution containing a cupric complex and an organic acid is allowed to act in the presence of oxygen, an etching solution containing sulfuric acid and hydrogen peroxide, and a method in which an etching solution containing sulfuric acid, hydrogen peroxide and halogen is made to act. As a plating method, for example, Cu- by electroless plating
Acicular or porous roughened layer 11 made of Ni-P alloy
And the like.

The metal used to form the coating layer 18 on the roughened surface or the roughened layer 11 is preferably a metal having a higher ionization tendency than titanium and no more than titanium or a noble metal.

The coating layer 18 made of such a metal is formed for the purpose of preventing local electrode reaction and preventing dissolution of the conductor circuit in a process such as acid cleaning of the substrate. The thickness is desirably 0.01 to 2 μm.

Examples of such metals include titanium, aluminum, zinc, iron, indium, thallium,
Examples include cobalt, nickel, tin, lead, and bismuth. Examples of the noble metal include gold, silver, platinum, and palladium. These may be used alone or in combination of two or more to form a plurality of layers.

As a method for forming the coating layer 18, for example, a method using an electroless plating solution containing a metal salt, a complexing agent, a reducing agent, and a surfactant is exemplified.

Examples of the above metal salts include tin salts, zinc salts, nickel salts, cobalt salts, thallium salts, lead salts and the like. These salts may be used alone.
More than one species may be used in combination. Examples of the tin salt include tin borofluoride, tin chloride, potassium stannate (sodium stannate), tin sulfate and the like.

Examples of the zinc salt include zinc chloride,
Examples include zinc bromide and zinc iodide. Examples of the nickel salt include nickel chloride and nickel sulfate. Examples of the cobalt salt include cobalt chloride. Examples of the thallium salt include thallium chloride, and examples of the lead salt include lead chloride and lead nitrate.

As the complexing agent, for example, thiourea,
Thiomalic acid, thiourea derivatives and the like. Examples of the reducing agent include sodium hypophosphite, formaldehyde, sodium borohydride, hydrazine,
Dimethylamine borane and the like can be mentioned. By incorporating the reducing agent, it is possible to prevent the conductor circuit from being oxidized by the plating solution.

Examples of the surfactant include polyethylene glycol (PEG), polypropylene oxide, polyethylene oxide and the like. They are,
They may be used alone or in combination of two or more.

The concentration of each compound in the electroless plating solution containing the metal salt or the like is such that the concentration of the metal salt is 0.1%.
1 to 5 mol / l, the concentration of the complexing agent is 0.1 to 2 mol
1 / l, the concentration of the reducing agent is preferably 1 to 40 g / l, and the concentration of the surfactant is preferably 0.1 to 10 g / l.

The electroless plating solution in which the above-mentioned compound such as a metal salt is mixed may be, for example, a mixed solution containing an organic acid and a cupric complex or a mixed solution containing sulfuric acid and hydrogen peroxide. It is suitable for forming a coating layer on a roughened surface formed by the used etching process. Usually, the roughness of the roughened surface formed by the etching process is not so large, but the electroless plating solution can form a more uniform and thin coating layer along the unevenness of the roughened surface. . Further, the coating layer formed using the above electroless plating solution, without damaging the roughened surface or the roughened layer formed thereunder,
It is excellent in that it can be easily peeled off by etching.

The above-mentioned electroless plating solution may further contain gelatin in addition to the above-mentioned compound such as a metal salt. By blending gelatin and selecting its type and amount (concentration), the deposition state of the electroless plating film can be more easily controlled. The above-mentioned gelatin is a protein in which collagen is irreversibly converted to water-soluble by boiling in water, and denatured by breaking the secondary structure of collagen molecules due to cleavage of salt bonds and hydrogen bonds between peptide chains. Is preferred.

The concentration of the above gelatin is not particularly limited, but is preferably from 100 to 2000 mg / l. If the concentration of gelatin is less than 100 mg / l, the deposition rate cannot be controlled, so that whiskers may occur in the coating layer and short circuits may occur between the conductor circuits. In some cases, the roughened surface or the portion not covered with the roughened layer may occur due to excessive coating, or the deposition of plating may stop.

When the above-mentioned gelatin is mixed with the above-mentioned electroless plating solution, the mixing ratio of the above-mentioned gelatin and the above-mentioned surfactant is preferably 0.5 to 2.0: 0.5 to 2.0 by weight ratio. 1: 1 is more preferred. By adding the above gelatin and the above surfactant in a ratio of about 1: 1, it is easy to control the rate of precipitation, and it is easy to maintain the stability of the plating solution.

Specific examples of the electroless plating solution containing a tin salt include tin borofluoride and thiourea or tin chloride and thiourea with a reducing agent such as sodium hypophosphite and a surfactant such as polyethylene glycol. And, if necessary, gelatin.

In the case of forming a metal layer made of a metal having a relatively high ionization tendency such as titanium or aluminum or a noble metal, a method such as sputtering or vapor deposition may be employed.

Of the metals constituting the coating layer 18, tin is desirable. This is because tin can form a thin layer by electroless displacement plating, and can follow the shape of the roughened surface or the roughened layer 11. In the case of forming a metal layer made of tin, displacement plating is performed using an electroless plating solution such as a solution containing tin borofluoride and thiourea or a solution containing tin chloride and thiourea. in this case,
The Sn layer having a thickness of about 0.01 to 2 μm is formed by the substitution reaction of Cu—Sn.

In the present invention, after forming a via hole opening in the interlayer resin insulating layer 2, at least a portion of the coating layer 18 on the roughened surface or the roughened layer 11 exposed from the via hole opening is removed. By doing so, the adhesion to the via hole 7 formed in a later step is improved.

When removing at least a part of the coating layer 18, it is desirable to remove the entire coating layer 18 in the via hole opening as shown in FIGS. 1 (a) and 1 (b). As shown in FIGS. 3A and 3B or FIGS. 3A and 3B, only a part of the coating layer 18 in the via hole opening may be removed. By removing a part of the covering layer 18, a multilayer printed circuit in which the connection reliability and electrical connectivity between the via hole and the conductor circuit are secured almost equal to the multilayer printed wiring board from which the covering layer 18 is entirely removed. This is because a wiring board can be manufactured.

In particular, as the metal forming the coating layer 18,
When tin or the like is used, the connection reliability and the electrical connection between the via hole and the conductor circuit are significantly improved only by removing a part of the coating layer 18.

When a part of the coating layer 18 is removed, the part to be removed is not particularly limited. As shown in FIGS. 2A and 2B, the portion to be removed is located at the center of the coating layer 18 in the via hole opening. 3 (a) and 3 (b), the peripheral portion of the coating layer 18 in the via hole opening, or another portion. That is, by removing a part of the coating layer 18 in the via hole opening,
The via hole 7 and the roughened surface or the roughened layer 11 form the coating layer 1.
It suffices if the connection can be established without going through 8.

When removing the coating layer, an alkaline solution containing 1 to 40% by weight of an acid or an oxidizing agent,
It is desirable to perform the etching treatment using a mixed solution composed of an acid and a peroxide by weight. The acid is desirably at least one selected from the group consisting of hydrochloric acid, nitric acid, sulfuric acid, hydrofluoric acid, phosphoric acid, and formic acid. Among them, hydrochloric acid and nitric acid are particularly preferable because the metal forming the coating layer can be removed in a short time and the influence on the roughened surface or the unevenness of the roughened layer is small.

The peroxide includes an oxide having O ₂ ^2- . Specific examples include, for example, metal peroxides such as potassium peroxide, sodium peroxide, and magnesium peroxide, and peroxides such as benzoyl peroxide, acetyl peroxide, hydrogen peroxide, formic acid, peracetic acid, and perbenzoic acid. Examples include an acyl derivative of hydrogen and an aroyl derivative. Among these, hydrogen peroxide and potassium peroxide are desirable from the viewpoint of inexpensiveness and easy handling. Examples of a mixed solution containing 1 to 40% by weight of an acid and a peroxide using these peroxides include a mixed solution containing 1 to 40% by weight of nitric acid and hydrogen peroxide, or 1 to 40% by weight. Of a mixture of hydrofluoric acid and hydrogen peroxide. This is because nitric acid or hydrofluoric acid has an oxidizing property, so that the metal forming the coating layer can be removed cleanly in a short time, and has little effect on the roughened surface or the unevenness of the roughened layer. In addition to,
By mixing the peroxide, nitrite ions and the like generated in the etching process can be oxidized to nitric acid or the like, so that the metal such as copper constituting the conductor circuit is not etched by the nitric acid or the like, This is because only the coating layer can be reliably removed. Furthermore, since the coating layer can be almost uniformly removed by using the above-mentioned mixed solution, it is suitable for removing the entire coating layer exposed at the via hole opening without leaving any residue.

In the case of using the above-mentioned mixture of 1 to 40% by weight of acid and peroxide, the mixing ratio of 1 to 40% by weight of acid and peroxide is not particularly limited. It is desirable that peroxide = 1 to 5: 1. If the amount of the peroxide is too small, nitrite ions and the like generated in the etching step cannot be oxidized in a short time, and the roughened surface or the roughened layer formed on the conductor circuit may be damaged. On the other hand, if the amount of the peroxide is too large, the interlayer resin insulating layer may be damaged.

That is, after forming an opening for a via hole in the interlayer resin insulating layer, the substrate is removed, for example, by 1 to 40% by weight.
Immersed in hydrochloric acid or nitric acid at a concentration of
0.1-5 mol / l of alkali such as OH, and K
Immersion in an alkaline solution containing 0.1 to 5 mol / l of MnO ₄ for 1 to 5 minutes, or 25 to 6% of 1 to 40% by weight of nitric acid or hydrofluoric acid and hydrogen peroxide solution
By immersing in a mixed aqueous solution at 0 ° C. for 1 to 20 minutes,
Only the coating layer made of tin or the like can be completely removed without substantially etching the lower conductive circuit and its roughened surface or roughened layer.

At this time, the temperature of the acid is preferably 30 to 50 ° C., the temperature of the alkaline solution is preferably 50 to 80 ° C., and the temperature of the mixture of the acid and the peroxide is 25 to 60 ° C. Is preferred.

The multilayer printed wiring board of the present invention has a roughened surface, and an interlayer resin insulating layer is formed on a substrate on which a conductor circuit having a metal coating layer is formed on the roughened surface. A via hole opening is formed in the interlayer resin insulating layer; and a conductor layer is formed in the via hole opening to form a via hole. The circuit part is
At least a part of the metal coating layer is removed, and the roughened surface is directly connected to the conductor layer.

According to the structure of the present invention, at least a part of the metal coating layer is removed from the conductor circuit portion in the via hole opening, and the roughened surface is directly connected to the conductor layer. Therefore, the roughened surface of the conductor circuit surface and the via hole adhere to each other, and therefore, the adhesion between the conductor circuit and the via hole is improved.

Further, since the roughened surface is directly connected to the conductor layer, it is possible to prevent the conductor layer from peeling off due to the stress generated due to the difference in the thermal expansion coefficient under the heat cycle condition and the difference in electric transmission speed. No resulting signal delay or signal error occurs. Therefore, it is possible to provide a multilayer printed wiring board in which the connection reliability and electrical connection between the via hole and the conductor circuit are sufficiently ensured.

Next, a method of manufacturing a multilayer printed wiring board according to the present invention will be described by taking a semi-additive method as an example. (1) First, a substrate having an inner copper pattern (lower conductive circuit) formed on the surface of a core substrate is prepared. When forming a conductor circuit for this core substrate, a method of etching a copper-clad laminate into a specific pattern, a method of forming an adhesive layer for electroless plating on a substrate such as a glass epoxy substrate, a polyimide substrate, a ceramic substrate, and a metal substrate. Forming, after roughening the surface of the adhesive layer for electroless plating to a roughened surface, a method of performing electroless plating, or performing electroless plating on the entire roughened surface to form a plating resist, Using a method (semi-additive method) of forming a conductor circuit consisting of an electrolytic plating film and an electroless plating film by applying a plating resist after removing the plating resist after applying electrolytic plating to the portion where no plating resist is formed, and performing an etching process. Can be.

Usually, after a conductive circuit is formed on a substrate, a low-viscosity resin filler such as bisphenol F epoxy resin is filled between the through-hole and the conductive circuit of the core substrate, and then the resin layer and the conductive circuit are polished. By doing so, the smoothness between the resin layer and the conductor circuit is ensured, but a roughened surface or a roughened layer is formed on the surface of the conductor circuit before filling with the resin filler.

Note that a through hole may be formed in the core substrate, and the wiring layers on the front and back surfaces may be electrically connected via the through hole.

The roughened surface or the roughened layer is desirably formed by any one of a polishing treatment, an etching treatment, a blackening reduction treatment and a plating treatment. Of these processes, when performing the blackening reduction process, NaOH
(20 g / l), NaClO ₂ (50 g / l), Na ₃
A blackening bath (oxidizing bath) composed of an aqueous solution containing PO ₄ (15.0 g / l), NaOH (2.7 g / l), Na
A method of forming a roughened surface using a reducing bath composed of an aqueous solution containing BH ₄ (1.0 g / l) is desirable.

When a roughened layer is formed by plating, copper sulfate (1 to 40 g / l), nickel sulfate (0.1 to 6.0 g / l), and citric acid (10 to 20 g / l) are used.
l), sodium hypophosphite (10-100 g / l),
Boric acid (10 to 40 g / l), surfactant (Surfynol 465, manufactured by Nissin Chemical Industry Co., Ltd.) (0.01 to 10 g / l)
It is preferable to form a roughened layer made of a Cu-Ni-P alloy by performing electroless plating in an electroless plating bath having a pH of 9 and containing l). This is because the crystalline structure of the film deposited in this range has a needle-like structure, and thus has an excellent anchor effect. A complexing agent or an additive may be added to the electroless plating bath in addition to the above compounds.

As the above-mentioned etching method, there is a method in which an etching solution containing a cupric complex and an organic acid is allowed to act in the presence of oxygen to roughen the surface of the conductor circuit. In this case, the etching proceeds by the chemical reaction of the following formulas (1) and (2).

[0055]

Embedded image

As the cupric complex, a cupric complex of an azole is desirable. This cupric complex of azoles is
It acts as an oxidizing agent that oxidizes metallic copper and the like. Examples of the azoles include diazole, triazole, and tetrazole. Among these, imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-undecylimidazole and the like are desirable. The content of the cupric complex of azoles in the etching solution is desirably 1 to 15% by weight. This is because it is excellent in solubility and stability, and can also dissolve noble metals such as Pd constituting the catalyst core.

In order to dissolve the copper oxide, an organic acid is added to the azole cupric complex. Specific examples of the organic acid include, for example, formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, acrylic acid, crotonic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, maleic acid, benzoic acid, Glycolic acid, lactic acid, malic acid, sulfamic acid and the like can be mentioned. These may be used alone or in combination of two or more.

The content of the organic acid in the etching solution is 0.1%.
1 to 30% by weight is desirable. This is because the solubility of the oxidized copper can be maintained and the solubility stability can be ensured. As shown in the above formula (2), the generated cuprous complex dissolves under the action of an acid and combines with oxygen to form a cupric complex, which again contributes to oxidation of copper.

To assist in dissolving copper and oxidizing azoles, halogen ions, for example, fluorine ions, chlorine ions, bromine ions, etc., may be added to the etching solution. Also, halogen ions can be supplied by adding hydrochloric acid, sodium chloride, or the like. The content of halogen ions in the etching solution is 0.01 to 20.
% By weight is desirable. This is because adhesion between the formed roughened surface and the interlayer resin insulating layer is excellent.

In preparing the etching solution, a cupric complex of azoles and an organic acid (if necessary, having a halogen ion) are dissolved in water. As the etching solution, a commercially available etching solution, for example, “Mech Etch Bond” manufactured by Mec Co., Ltd. is used.
Etching amount (roughness) when using the above etching solution
Is preferably 1 to 5 μm. When the etching amount exceeds 5 μm, the adhesion between the formed roughened surface and the resin is reduced, and
On the other hand, if the etching amount is less than 1 μm, the adhesion to the interlayer resin insulating layer formed thereon becomes insufficient.

In addition to the above, the above etching treatment can be performed using a mixed solution containing sulfuric acid, a hydrogen peroxide solution, a mixed solution containing sulfuric acid, a hydrogen peroxide solution, and a halogen.

The roughened surface or the roughened layer formed by the above method is usually polished while leaving the side surfaces, so that the smoothness between the resin layer and the conductor circuit is ensured.

Thereafter, the conductor circuit is again subjected to a roughening treatment. In this case, the roughening treatment is performed by any of the above-mentioned methods, that is, the polishing treatment, the etching treatment, the blackening reduction treatment, and the plating treatment. It is desirable to form a roughened surface or a roughened layer. After forming the roughened surface or the roughened layer on the conductor circuit, the interlayer resin insulating layer may be formed without performing the polishing treatment.

(2) Next, a coating layer made of a metal such as Sn is formed on the roughened surface or the roughened layer by a plating method or a sputtering method.

(3) Next, a resin insulating layer is formed on the substrate prepared in the above (2). As the resin insulating layer,
For example, it can be formed by applying a resin composition for forming a roughened surface containing an organic solvent, followed by drying.

The above resin composition for forming a roughened surface comprises an acid, an alkali, and a non-cured heat-resistant resin matrix which is hardly soluble in a roughening solution comprising at least one selected from an acid, an alkali and an oxidizing agent. It is desirable that a substance that is soluble in a roughening liquid composed of at least one selected from an oxidizing agent and a oxidizing agent is dispersed. Note that the terms "poorly soluble" and "soluble" used in the present invention, when immersed in the same roughening solution for the same time, those having a relatively high dissolution rate are referred to as "soluble" for convenience, and Those with a slow dissolution rate are called "poorly soluble" for convenience.

As the heat-resistant resin matrix, for example, a thermosetting resin or a composite of a thermosetting resin (including one in which a part of the thermosetting group is sensitized) and a thermoplastic resin are used. Can be.

The thermosetting resin includes, for example, epoxy resin, phenol resin, polyimide resin, thermosetting polyolefin resin and the like. When the thermosetting resin is exposed to light, a methacrylic acid, acrylic acid, or the like is used to cause the thermosetting group to undergo a (meth) acrylation reaction. Particularly, epoxy resin (meth) acrylate is most suitable.

As the epoxy resin, for example, a novolak type epoxy resin, an alicyclic epoxy resin or the like can be used. As the thermoplastic resin, for example, polyether sulfone, polysulfone, polyphenylene sulfone, polyphenylene sulfide, polyphenyl ether, polyether imide, and the like can be used.

The substance soluble in the roughening liquid comprising at least one selected from the above-mentioned acids, alkalis and oxidizing agents is selected from inorganic particles, resin particles, metal particles, rubber particles, liquid resin and liquid rubber. It is desirable that it is at least one kind.

Examples of the inorganic particles include silica,
Examples include alumina, calcium carbonate, talc, and dolomite. These may be used alone or in combination of two or more. The alumina particles can be dissolved and removed with hydrofluoric acid, and the calcium carbonate can be dissolved and removed with hydrochloric acid. Further, sodium-containing silica and dolomite can be dissolved and removed with an alkaline aqueous solution.

Examples of the resin particles include amino resins (melamine resin, urea resin, guanamine resin, etc.),
Epoxy resins, bismaleimide-triazine resins and the like can be mentioned. These may be used alone or in combination of two or more. The epoxy resin can be arbitrarily manufactured by dissolving in an acid or an oxidizing agent or hardly dissolving in the acid or the oxidizing agent by selecting the type of the oligomer and the curing agent. For example, a resin obtained by curing a bisphenol A-type epoxy resin with an amine-based curing agent is very soluble in chromic acid, but a resin obtained by curing a cresol novolac-type epoxy resin with an imidazole curing agent is not easily dissolved in chromic acid. .

It is necessary that the resin particles have been previously cured. If not cured, the resin particles will dissolve in the solvent that dissolves the resin matrix, so they will be uniformly mixed, and it will not be possible to selectively dissolve and remove only the resin particles with an acid or oxidizing agent. is there.

The metal particles include, for example, gold, silver,
Examples include copper, tin, zinc, stainless steel, and aluminum. These may be used alone or in combination of two or more. Examples of the rubber particles include acrylonitrile-butadiene rubber, polychloroprene rubber,
Polyisoprene rubber, acrylic rubber, polysulfuric rigid rubber,
Fluorine rubber, urethane rubber, silicone rubber, ABS resin and the like can be mentioned. These may be used alone,
Two or more kinds may be used in combination.

An uncured solution of the thermosetting resin can be used as the liquid phase resin. Specific examples of such a liquid phase resin include, for example, an uncured epoxy oligomer and an amine-based curing agent. And the like. As the liquid phase rubber, for example, an uncured solution of the rubber can be used.

When the photosensitive resin composition is prepared using the liquid phase resin or the liquid phase rubber, the heat-resistant resin matrix and the soluble substance are not uniformly compatible (that is, so as to separate phases). First, it is necessary to select these substances. By mixing a heat-resistant resin matrix and a soluble substance selected according to the above criteria, a state in which "islands" of liquid-phase resin or liquid-phase rubber are dispersed in the "sea" of the heat-resistant resin matrix Alternatively, a photosensitive resin composition in which "islands" of a heat-resistant resin matrix are dispersed in a "sea" of a liquid phase resin or a liquid phase rubber can be prepared.

After the photosensitive resin composition in such a state is cured, the roughened surface can be formed by removing the "sea" or "island" liquid phase resin or liquid phase rubber. .

Examples of the acid used as the roughening solution include phosphoric acid, hydrochloric acid, sulfuric acid, and organic acids such as formic acid and acetic acid. Among them, it is 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. As the oxidizing agent, for example, an aqueous solution of chromic acid, an alkaline permanganate (such as potassium permanganate), or the like is desirably used. As the alkali, an aqueous solution of sodium hydroxide, potassium hydroxide or the like is desirable.

In the present invention, when the above-mentioned inorganic particles, the above-mentioned metal particles and the above-mentioned resin particles are used, the average particle size is desirably 10 μm or less. Further, in particular, by using a mixture of coarse particles having a relatively large average particle diameter and fine particles having a relatively small average particle diameter having an average particle diameter of less than 2 μm, the electroless plating film Dissolved residues can be eliminated, the amount of palladium catalyst under the plating resist can be reduced, and a shallow and complicated roughened surface can be formed. By forming such a complicated roughened surface, a practical peel strength can be maintained even on a shallow roughened surface.

The combination of the coarse particles and the fine particles can form a shallow and complicated roughened surface because the coarse particles used are coarse particles having an average particle size of less than 2 μm. The anchor formed even when dissolved is removed becomes shallow, and the particles to be removed are formed by the mixture of coarse particles having a relatively large particle diameter and fine particles having a relatively small particle diameter. The roughened surface becomes complicated. In this case, since the particle diameter used is coarse particles and the average particle diameter is less than 2 μm, the coarsening does not proceed too much to generate voids, and the formed resin insulating layer has excellent interlayer insulating properties. I have.

The coarse particles have an average particle diameter of more than 0.8 μm and less than 2.0 μm, and the fine particles have an average particle diameter of 0.1 to 0.1 μm.
Preferably, it is 0.8 μm. In this range, the depth of the roughened surface is approximately Rmax = about 3 μm. With the semi-additive method, not only the electroless plating film is easily removed by etching, but also the Pd catalyst under the electroless plating film is easily removed. And a practical peel strength of 1.0 to 1.3 kg / cm can be maintained.

The content of the organic solvent in the above-mentioned resin composition for forming a roughened surface is desirably 10% by weight or less. When applying the resin composition for forming a roughened surface, a roll coater, a curtain coater, or the like can be used.

The resin insulating layer can be formed using, for example, a polyphenylene ether resin, a thermoplastic elastomer resin, a polyolefin resin, a fluororesin, a triazine resin, or the like.

Examples of the polyphenylene ether resin include a thermoplastic polyphenylene ether resin having a repeating unit represented by the following chemical formula (3) and a thermosetting polyphenylene ether resin having a repeating unit represented by the following chemical formula (4): And the like.

[0085]

Embedded image

(In the formula, n represents an integer of 2 or more.)

[0087]

Embedded image

(Wherein, m represents an integer of 2 or more. R ¹ and R ² represent a methylene group, an ethylene group or a —C
Represents H ₂ —O—CH ₂ —, both of which may be the same or different. )

The thermoplastic polyphenylene ether resin having a repeating unit represented by the above chemical formula (3) has a structure in which a methyl group is bonded to a benzene ring, but the polyphenylene ether which can be used in the present invention. The resin may be a derivative in which the above-mentioned methyl group is substituted with another alkyl group such as an ethyl group, or a derivative in which hydrogen of a methyl group is substituted with fluorine.

The thermoplastic elastomer resin is not particularly restricted but includes, for example, styrene-based thermoplastic elastomers, olefin-based thermoplastic elastomers, urethane-based thermoplastic elastomers, polyester-based thermoplastic elastomers, polyamide-based thermoplastic elastomers, -Polybutadiene-based thermoplastic elastomers, PVC-based thermoplastic elastomers, fluorine-based thermoplastic elastomers, and the like. Among these, olefin-based thermoplastic elastomers and fluorine-based thermoplastic elastomers are desirable from the viewpoint of excellent electrical properties.

The above-mentioned polyolefin resin is not particularly restricted but includes, for example, polyethylene, polypropylene, polyisobutylene, polybutadiene, polyisoprene, cycloolefin resin and copolymers of these resins.

Examples of the commercially available polyolefin resin include, for example, 1592 (trade name, manufactured by Sumitomo 3M Limited). Commercially available thermoplastic polyolefin resins having a melting point of 200 ° C. or higher include, for example, TPX (trade name: 240 ° C., manufactured by Mitsui Petrochemical Co., Ltd.) and SPS (trade name, manufactured by Idemitsu Petrochemical Co., Ltd.) Melting point 270 ° C.). Among them, cyclo-dielectric materials have a low dielectric constant and a low dielectric loss tangent, are unlikely to cause signal delay and signal error even when a high-frequency signal in the GHz band is used, and are excellent in mechanical properties such as rigidity. Olefin resins are desirable.

As the cycloolefin-based resin, 2
Homopolymers or copolymers of monomers comprising -norbornene, 5-ethylidene-2-norbornene or derivatives thereof are desirable. As the above derivative, the above 2-
Examples thereof include those in which an amino group for forming a crosslink, a maleic anhydride residue, or a maleic acid-modified one is bonded to a cycloolefin such as norbornene. Examples of monomers for synthesizing the copolymer include ethylene and propylene.

The cycloolefin resin may be a mixture of two or more of the above resins, or may contain a resin other than the cycloolefin resin. When the cycloolefin resin is a copolymer, it may be a block copolymer or a random copolymer.

It is desirable that the cycloolefin resin is a thermosetting cycloolefin resin.
This is because by performing the heating to form the crosslinks, the rigidity is further increased and the mechanical properties are improved. The glass transition temperature (Tg) of the cycloolefin resin is 13
Desirably, the temperature is 0 to 200 ° C.

As the above cycloolefin-based resin, those already molded as a resin sheet (film) may be used, and a monomer or a low-molecular-weight polymer having a certain molecular weight may be used as a solvent such as xylene or cyclohexane. It may be in the state of an uncured solution dispersed in. In the case of a resin sheet, a so-called RCC (RESIN COATE
D COPER: resin-coated copper foil).

The cycloolefin resin may not contain a filler or the like, or may contain a flame retardant such as aluminum hydroxide, magnesium hydroxide, or a phosphate.

When the above-mentioned polyolefin resin is used, melamine, phenol resin, epoxy resin, polyimide resin, fluororesin, PP
Organic fillers such as O and PPE may be blended. By blending the organic filler, for example, when a via hole opening is formed by irradiating a resin insulating layer with a laser beam, a via hole opening having a desired shape can be favorably formed.

The content of the organic filler is preferably 5 to 60% by weight. The content of the organic filler is 5% by weight
When the content is less than the above, the content of the organic filler is too small, so that the above-mentioned role cannot be performed at the time of laser beam irradiation, and a non-through hole or the like having a desired shape may not be formed. On the other hand, when the content of the organic filler is 60
If the content is more than 10% by weight, the properties of the polyolefin resin are lost, and, for example, the dielectric constant may be too high. More preferred amount of the organic filler,
14 to 60% by weight.

Examples of the fluororesin include ethyl / tetrafluoroethylene copolymer resin (ETFE) and polychlorotrifluoroethylene (PCTFE).

When the resin insulating layer is formed by attaching the above-mentioned resin film, the resin insulating layer is formed using a device such as a vacuum laminator under reduced pressure or vacuum under a pressure of 2.0 to 10 kgf / cm ^2. Pressure, 60-1
It is preferable to perform pressure bonding at a temperature of 20 ° C., and then heat-harden the resin film. The heat curing may be performed after forming a via hole opening and a through hole described later.

The thickness of the resin insulating layer formed in the manufacturing method of the present invention is not particularly limited.
m is desirable. When the thickness is less than 5 μm, insulation between the vertically adjacent conductor circuits may not be maintained,
On the other hand, when the thickness exceeds 50 μm, when a non-through hole or the like is formed, resin residue may be generated at the bottom thereof, or the shape of the non-through hole or the like may be tapered toward the bottom.

The resin insulating layer preferably has a dielectric constant at 1 GHz of 3.0 or less and a dielectric loss tangent of 0.01 or less. The dielectric constant is more preferably 2.4 to 2.7. Examples of the resin having such a dielectric constant include a polyphenylene ether resin and a polyolefin resin. By using such a material having a low dielectric constant, it is possible to prevent a signal error due to a delay in signal propagation, a signal transmission loss, and the like.

(4) A via hole opening is provided in the resin insulating layer formed in (3). For example, after the roughened surface forming resin composition layer is dried to a semi-cured state, an opening for a via hole is provided. In the state where the resin composition layer for forming a roughened surface is dried, the thickness of the resin composition layer on the conductor circuit pattern is small, and the thickness of the resin insulating layer on the plane layer having a large area is large. In addition, since the resin insulating layer often has irregularities due to the irregularities of the conductor circuit and the portion where the conductor circuit is not formed, the resin insulation layer is pressed by heating using a metal plate or a metal roll. It is desirable to planarize the surface of the layer.

The opening for the via hole is formed by exposing the resin composition layer for forming a roughened surface or the like using ultraviolet rays or the like and then performing a developing treatment. In the case of performing the exposure and development processing, the side of the photomask (preferably a glass substrate) on which the black circle pattern is drawn is placed on the portion corresponding to the via hole opening described above. The substrate is placed in close contact with the resin composition layer for forming a roughened surface, and is exposed and developed.

The formation of the via hole opening can also be performed by using laser processing, plasma processing, or the like.
As the laser used for performing the laser processing, for example, a carbon dioxide gas laser, an excimer laser, a UV laser,
An AG laser and the like can be mentioned. These lasers may be used properly in consideration of the material of the resin insulating layer and the shape of the via hole opening. Note that the laser treatment is preferably performed by irradiating a portion corresponding to a portion for forming a via hole opening with a laser beam through a mask provided with a through hole.

In the case of forming the via hole openings, a large number of via hole openings can be formed at once by irradiating a laser beam with a hologram type excimer laser through a mask. Further, when the via hole opening is formed using a short-pulse carbon dioxide laser, the amount of resin remaining in the opening is small, and the damage to the resin at the periphery of the opening is small.

By irradiating a laser beam through an optical lens and a mask, a large number of via hole openings can be formed at once. This is because a plurality of portions can be simultaneously irradiated with laser light having the same intensity and the same irradiation angle through the optical lens and the mask.

The through-hole formed in the mask is desirably a perfect circle in order to make the spot shape of the laser beam a perfect circle, and the diameter of the through-hole is desirably about 0.1 to 2 mm.

When using the above carbon dioxide laser,
The pulse interval is desirably 10 ⁻⁴ to 10 ⁻⁸ seconds. The time for irradiating the laser for forming the opening is preferably 10 to 500 μsec.

When the opening for the via hole is formed by laser light, and particularly when a carbon dioxide gas laser is used, desmearing is desirably performed. The desmear treatment can be performed using an oxidizing agent composed of an aqueous solution such as chromic acid and permanganate. In addition, oxygen plasma, CF ₄
It may be treated by a mixed plasma of oxygen and oxygen, corona discharge or the like. The surface can also be modified by irradiating ultraviolet rays using a low-pressure mercury lamp. When a through hole is formed in the substrate on which the resin insulating layer is formed, the through hole is formed using a drill having a diameter of 50 to 300 μm, laser light, or the like.

(5) Next, the resin insulating layer made of the resin composition for forming a roughened surface is cured to form an interlayer resin insulating layer. If necessary, the interlayer resin insulating layer is roughened. In the case where the interlayer resin insulating layer is formed of a resin composition for forming a roughened surface, the roughening treatment includes inorganic particles, resin particles, metal particles, rubber particles, and a liquid phase resin present on the surface of the interlayer resin insulating layer. , At least one soluble substance selected from liquid phase rubber,
The removal is performed by using a roughening solution such as the above-described acid, oxidizing agent, and alkali. The depth of the roughened surface is desirably about 1 to 5 μm.

Also, when the interlayer resin insulating layer is a layer formed using a polyphenylene ether resin or a polyolefin resin, the interlayer resin insulating layer includes a via hole opening by being treated with the above-mentioned acid or the like or by plasma treatment. Its surface can be roughened.

Thereafter, when the roughened surface is formed by using an acid, an aqueous solution of an alkali or the like is used, and when the roughened surface is formed by using an oxidizing agent, a neutralizing solution is used. And it is desirable to neutralize the inside of the through hole. By this operation, the acid and the oxidizing agent are removed so that the next step is not affected.

(6) Next, the roughened substrate is
Immersed in an acid having a concentration of ４０40% by weight for 0.1 to 10 minutes, or immersed in an alkaline solution containing 0.1 to 5 mol / l of NaOH and 0.1 to 1 mol / l of KMnO ₄ , Alternatively, at least a part of the coating layer exposed in the via hole opening is subjected to an etching treatment by immersing in a mixed solution containing an acid and a peroxide having a concentration of 1 to 40% by weight for 1 to 20 minutes. Is removed. The removal of the coating layer may be performed before the roughening treatment (5). Thereafter, catalyst nuclei are provided on the roughened surface of the interlayer resin insulating layer. 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.

(7) Next, a thin-film conductor layer made of an electroless plating film or the like is formed on the entire roughened surface. The electroless plating film can be formed using, for example, an electroless plating solution having the following composition. That is, as the electroless plating solution, for example, EDTA (40 g / l), copper sulfate (8 g / l)
l), HCHO (10 ml / l), NaOH (8 g /
l) or an electroless plating solution containing NiSO ₄ (0.003
mol / l), tartaric acid (0.200 mol / l), copper sulfate (0.030 mol / l), HCHO (0.050 m
ol / l), NaOH (0.100 mol / l), α,
An electroless plating solution containing α'-bipyridyl (40 mg / l) and polyethylene glycol (PEG) (0.10 g / l) is exemplified. The thickness of the electroless plating film is 0.
1 to 5 μm is desirable, 0.5 to 3 μm is more desirable, and 2 to 3 μm is particularly desirable.

Further, the thin film conductor layer can be formed by using sputtering, vapor deposition or the like. In particular, when a roughened surface is not formed on the interlayer resin insulating layer, it is preferable to form the thin film conductor layer by sputtering. In addition, when forming a thin film conductor layer by sputtering or vapor deposition, the thickness is preferably 0.1 to 1.0 μm.

(8) Then, after laminating a photosensitive resin film (dry film) on a part of the thin film conductor layer such as an electroless plating film or applying a liquid resist, a plating resist pattern was drawn. A plating mask pattern is formed by placing a photomask (preferably a glass substrate) in close contact with the photosensitive resin film and performing exposure and development processing.

(9) Next, electrolytic plating is applied to the portion where the plating resist is not formed to form a conductor circuit and a via hole. Here, it is desirable to use copper plating as the electrolytic plating, and its thickness is desirably 1 to 20 μm.

(10) After removing the plating resist, a mixed solution of sulfuric acid and hydrogen peroxide or an aqueous solution of persulfate such as sodium persulfate, ammonium persulfate, potassium persulfate, ferric chloride, cupric chloride, etc. A thin conductor layer such as an electroless plating film is dissolved and removed with an etching solution such as hydrochloric acid, nitric acid, hot dilute sulfuric acid, or the like to form an independent conductor circuit. Thereafter, when a palladium catalyst is used, the palladium catalyst nucleus is dissolved and removed with chromic acid or the like. Note that a roughened surface may be formed on the surface of the conductor circuit at the same time as removing the thin-film conductor layer using an etching solution containing a cupric complex and an organic acid.

(11) Next, a roughened surface or a roughened layer is formed on the surface of the conductor circuit.
It is desirable to form by any one of the etching treatment, the blackening reduction treatment, and the plating treatment. Then, a coating layer made of a metal such as Sn is formed on the roughened surface or the roughened layer in the same manner as in the above (2).

(12) Next, an interlayer resin insulating layer is formed on the substrate by using the above-mentioned resin composition for forming a roughened surface by the same method as described above. (13) Thereafter, if necessary, the steps (4) to (12) are repeated to prepare a substrate on which the conductor circuit and the interlayer resin insulating layer are sequentially laminated.

(14) Next, a solder resist layer is formed on the surface of the substrate including the uppermost conductive circuit, a solder pad is formed by opening the solder resist layer, and a solder paste is applied to the solder pad. Filling and reflowing form solder bumps. Then, on the external board connection surface,
By arranging pins and forming solder balls, PGA (Pin Grid Array) and BGA (Ball Grid Arr
ay).

The above-mentioned solder resist layer can be formed, for example, using a solder resist composition comprising a polyphenylene ether resin, a polyolefin resin, a fluororesin, a thermoplastic elastomer, an epoxy resin, a polyimide resin and the like. As a specific example, for example, the same resin as the resin used when forming the interlayer resin insulating layer and the like can be mentioned.

Examples of the solder resist compositions other than those described above include, for example, a (meth) acrylate of a novolak type epoxy resin, an imidazole curing agent, a bifunctional (meth) acrylate monomer, and a molecular weight of 500 to 50.
A paste-like fluid containing a polymer of about 00 (meth) acrylate, a thermosetting resin such as a bisphenol-type epoxy resin, a photosensitive monomer such as a polyvalent acrylic monomer, a glycol ether-based solvent, and the like. It is desirable that the viscosity is adjusted to 1 to 10 Pa · s at 25 ° C.

(Meth) of the above novolak type epoxy resin
Examples of the acrylate include an epoxy resin obtained by reacting glycidyl ether of phenol novolak or cresol novolak with acrylic acid, methacrylic acid, or the like.

The bifunctional (meth) acrylic acid ester monomer is not particularly limited, and examples thereof include acrylic acid and methacrylic acid esters of various diols, and commercially available products of Nippon Kayaku Co., Ltd. R-604, PM
2, PM21 and the like.

The above solder resist composition may contain an elastomer or an inorganic filler. By being blended with the elastomer, the formed solder resist layer can absorb or reduce the stress even when a stress acts on the solder resist layer due to the flexibility and rebound resilience of the elastomer. As a result, cracks and peeling can be suppressed from occurring in the manufacturing process of the multilayer printed wiring board and in the solder resist layer after mounting electronic components such as IC chips on the manufactured multilayer printed wiring board. Even when it occurs, the crack does not grow large.

As a method of opening the solder resist layer, for example, a method of irradiating a laser beam, a method of exposure and development processing, and the like can be mentioned in the same manner as the method of forming an opening for a via hole.

When a photosensitive solder resist composition is used as the solder resist composition, after a solder resist layer is formed, a photoresist is placed on the solder resist layer, and exposed and developed. By performing the above, the solder resist layer can be opened.

The conductor circuit portion exposed by opening the solder resist layer is usually desirably covered with a corrosion-resistant metal such as nickel, palladium, gold, silver, and platinum. Specifically, nickel-gold, nickel-
It is desirable to form the coating layer with a metal such as silver, nickel-palladium, nickel-palladium-gold, and the like. The coating layer can be formed by, for example, plating, vapor deposition, electrodeposition, and the like, and among these, plating is preferable because of excellent uniformity of the coating layer.

In addition, a plasma treatment with oxygen, carbon tetrachloride, or the like may be appropriately performed for a character printing step for forming a product recognition character or the like or for modifying a solder resist layer. Although the above method is based on the semi-additive method, a full additive method may be employed.

[0133]

The present invention will be described in more detail below.

Example 1 A. Preparation of Resin Composition for Forming Roughened Surface of Upper Layer (1) A 25% acrylate of a cresol novolak type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., molecular weight: 2500) is dissolved in diethylene glycol dimethyl ether (DMDG) at a concentration of 80% by weight. 400 parts by weight of the resin solution, photosensitive monomer (Aronix M325, manufactured by Toa Gosei Co., Ltd.) 60
A mixed composition was prepared by placing parts by weight, 5 parts by weight of an antifoaming agent (S-65, manufactured by San Nopco) and 35 parts by weight of N-methylpyrrolidone (NMP) in a container and mixing with stirring.

(2) Polyether sulfone (PES) 8
0 parts by weight, 72 parts by weight of an epoxy resin particle (manufactured by Sanyo Chemical Industries, polymer pole) having an average particle size of 1.0 μm and 31 parts by weight of an epoxy resin particle having an average particle size of 0.5 μm were placed in another container and mixed with stirring. And 257 parts by weight of NMP were further added and stirred and mixed by a bead mill to prepare another mixed composition.

(3) Imidazole curing agent (manufactured by Shikoku Chemicals, Inc.)
2E4MZ-CN), 20 parts by weight of a photopolymerization initiator (benzophenone), a photosensitizer (manufactured by Ciba-Geigy,
4 parts by weight of EAB) and 16 parts by weight of NMP were placed in another container and mixed by stirring to prepare a mixed composition. Then, a resin composition for forming a roughened surface was obtained by mixing the mixed compositions prepared in (1), (2) and (3).

B. Preparation of Resin Composition for Forming Lower Surface Roughened Surface (1) Dissolve 25% acrylate of cresol novolac type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., molecular weight: 2500) in diethylene glycol dimethyl ether (DMDG) at a concentration of 80% by weight. 400 parts by weight of the resin solution, photosensitive monomer (Aronix M325, manufactured by Toa Gosei Co., Ltd.) 60
A mixed composition was prepared by placing parts by weight, 5 parts by weight of an antifoaming agent (S-65, manufactured by San Nopco) and 35 parts by weight of N-methylpyrrolidone (NMP) in a container and mixing with stirring.

(2) Polyether sulfone (PES) 8
0 parts by weight and 145 parts by weight of an epoxy resin particle (manufactured by Sanyo Kasei Co., Ltd., polymer pole) having an average particle size of 0.5 μm are placed in another container, mixed with stirring, and further mixed with NMP2.
85 parts by weight were added and mixed by stirring with a bead mill to prepare another mixed composition.

(3) Imidazole curing agent (manufactured by Shikoku Chemicals, Inc.)
2E4MZ-CN), 20 parts by weight of a photopolymerization initiator (benzophenone), a photosensitizer (manufactured by Ciba-Geigy,
4 parts by weight of EAB) and 16 parts by weight of NMP were placed in another container and mixed by stirring to prepare a mixed composition. Then, an adhesive for electroless plating was obtained by mixing the mixed compositions prepared in (1), (2) and (3).

C. Preparation of resin filler (1) 100 parts by weight of bisphenol F type epoxy monomer (manufactured by Yuka Shell Co., molecular weight: 310, YL983U),
SiO ₂ spherical particles having an average particle diameter of 1.6 μm and a maximum particle diameter of 15 μm or less (CRS 1101 manufactured by Adtec Co., Ltd.) having a surface coated with a silane coupling agent.
-CE) 170 parts by weight and 1.5 parts by weight of a leveling agent (Perenol S4 manufactured by San Nopco) are placed in a container, and the mixture is stirred and mixed to have a viscosity of 23 to 1 ° C. and 45 to 45 ° C.
A resin filler of 49 Pa · s was prepared. As the curing agent, an imidazole curing agent (2E4MZ manufactured by Shikoku Chemicals Co., Ltd.)
-CN) 6.5 parts by weight.

D. Manufacturing method of printed wiring board (1) 0.6 mm thick glass epoxy resin or BT
A starting material was a copper-clad laminate in which 18 μm copper foils 8 were laminated on both sides of a substrate 1 made of (bismaleimide triazine) resin (see FIG. 4A). First, the copper-clad laminate was drilled, subjected to an electroless plating treatment, and etched in a pattern to form a lower conductor circuit 4 and a through hole 9 on both surfaces of the substrate 1.

(2) Through hole 9 and lower conductor circuit 4
After the substrate on which was formed was washed with water and dried, NaOH (1
0 g / l), NaClO ₂ (40 g / l), Na ₃ PO
₄ A blackening treatment using an aqueous solution containing (16 g / l) as a blackening bath (oxidizing bath), NaOH (19 g / l), NaB
A reduction treatment was performed using an aqueous solution containing H ₄ (5 g / l) as a reduction bath, and roughened surfaces 4 a and 9 a were formed on the entire surface of the lower conductor circuit 4 including the through holes 9 (see FIG. 4B). ).

(3) By applying the resin filler 10 to one surface of the substrate using a roll coater, the lower conductive circuit 4
After filling in the space or in the through hole 9 and drying by heating, the resin filler 10 is similarly filled between the conductor circuits 4 or in the through hole 9 on the other surface and dried by heating (FIG. 4 (c)). )reference).

(4) One surface of the substrate after the treatment of the above (3) is subjected to belt sander polishing using # 600 belt polishing paper (manufactured by Sankyo Rikagaku) 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 caused by the belt sander polishing. Such a series of polishing was similarly performed on the other surface of the substrate. Then, at 100 ° C for 1 hour, at 120 ° C for 3 hours, at 150 ° C
For 1 hour and a heat treatment at 180 ° C. for 7 hours to cure the resin filler 10.

In this way, the surface layer of the resin filler 10 formed in the through-hole 9 and the portion where the conductor circuit is not formed and the surface of the lower conductor circuit 4 are flattened, and the resin filler 10 and the side surface of the lower conductor circuit 4 are flattened. 4a is firmly adhered through the roughened surface, and the inner wall surface 9a of the through hole 9 and the resin filler 10
Was firmly adhered through the roughened surface to obtain an insulating substrate (see FIG. 4D). By this step, the resin filler 10
And the surface of the lower conductor circuit 4 are flush with each other. Here, the filled resin had a Tg point of 155.6 ° C. and a linear thermal expansion coefficient of 44.5 × 10 ⁻⁶ / ° C.

(5) On the upper surface of the land of the inner conductor circuit 4 and the through hole 9 exposed in the processing of (4), a thickness of 2.5
Roughened layer (concavo-convex layer) 1 made of μm Cu-Ni-P alloy
1 on the surface of the roughened layer 11.
A 3 μm Sn layer was provided (see FIG. 5A, except that Sn layer
The layers are not shown). The formation method is as follows. That is, copper sulfate (8 g / l), nickel sulfate (0.6 g / l), citric acid (15 g / l), sodium hypophosphite (29 g / l), boric acid (31 g / l),
Surfactant (Surfinol 46, manufactured by Nissin Chemical Industry Co., Ltd.)
5) The substrate was immersed in an electroless copper plating bath at pH = 9 consisting of an aqueous solution containing (0.1 g / l), and after 1 minute of immersion, vibrated vertically and horizontally at a rate of once every 4 seconds. The surface of the land of the lower conductor circuit and the through hole is
A roughened layer 11 of a needle-like alloy made of -Ni-P was provided. Furthermore, a temperature of 50 ° C. containing tin borofluoride (0.1 mol / l) and thiourea (1.0 mol / l), pH = 1.2
Cu-Sn substitution reaction was performed using the plating bath of No. 1, and a Sn layer having a thickness of 0.3 μm was provided on the surface of the roughened layer.

(6) An adhesive for electroless plating of B (viscosity: 1.5 Pa · s) was applied to both surfaces of the substrate by a roll coater, left in a horizontal state for 20 minutes, and then left at 60 ° C. for 30 minutes. Was dried to form an adhesive layer 2a for electroless plating. Further, the adhesive for electroless plating (A) (viscosity: 7 Pa · s) is applied on the adhesive layer for electroless plating 2 a using a roll coater, and left in a horizontal state for 20 minutes. After drying for 30 minutes, an adhesive layer 2b was formed, and an adhesive layer 2 for electroless plating having a thickness of 35 μm was formed (see FIG. 5B).

(7) The adhesive layer 2 for electroless plating according to the above (6)
A photomask film on which a black circle having a diameter of 85 μm is printed is brought into close contact with both surfaces of the substrate 1 on which is formed, and is exposed at an intensity of 500 mJ / cm ² by an ultra-high pressure mercury lamp, and then DMDG
Spray developed with the solution. Thereafter, the substrate is further exposed to an ultrahigh pressure mercury lamp at an intensity of 3000 mJ / cm ² , and subjected to a heat treatment at 100 ° C. for 1 hour and at 150 ° C. for 5 hours to obtain a diameter excellent in dimensional accuracy equivalent to a photomask film. Thickness 3 having 85 μm via hole opening 6
An interlayer resin insulating layer 2 of 5 μm was formed (see FIG. 5C).

(8) The substrate in which the via hole opening 6 was formed was placed in a 70 ° C. solution containing 800 g / l of chromic acid for 19 hours.
Then, the surface of the interlayer resin insulating layer 2 was roughened (3 μm in depth) by dissolving and removing the epoxy resin particles present on the surface of the interlayer resin insulating layer 2 (see FIG. 5D).

(9) Next, the substrate after the above processing is
The substrate was immersed in 3% by weight of hydrochloric acid for 3 minutes, the exposed Sn layer on the surface of the conductor circuit 5 was removed by etching, and then immersed in a neutralizing solution (manufactured by Shipley) and then washed with water. The state where the Sn layer is removed is not shown in the drawings. Further, by applying a palladium catalyst (manufactured by Atotech) to the surface of the substrate subjected to the surface roughening treatment, catalyst nuclei were attached to the surface of the interlayer resin insulating layer 2 and the inner wall surface of the via hole opening 6.

(10) Next, the substrate was immersed in an aqueous electroless copper plating solution having the following composition to form an electroless copper plating film 12 having a thickness of 0.8 μm on the entire rough surface (FIG. 6 (a)). )reference).
At this time, since the plating film was thin, irregularities were observed on the surface of the electroless plating film. [Electroless plating aqueous solution] EDTA 40 g / l Copper sulfate 8 g / l HCHO 10 ml / l NaOH 10 g / l α, α'-bipyridyl 80 mg / l Polyethylene glycol (PEG) 0.1 g / l Electroplating conditions] 15 minutes at a liquid temperature of 70 ° C

(11) A commercially available photosensitive dry film was stuck on the electroless copper plating film 12, and a mask was placed thereon.
Exposure at mJ / cm ² and development with a 0.8% aqueous sodium carbonate solution provided a plating resist 3 (see FIG. 6B).

(12) Next, the substrate was washed with water at 50 ° C., degreased, washed with water at 25 ° C., further washed with sulfuric acid, and then subjected to electrolytic copper plating under the following conditions. The film 13 was formed (see FIG. 6C). [Electrolytic plating aqueous solution] Sulfuric acid 180 g / l Copper sulfate 80 g / l Additive 1 ml / l (Capparaside GL, manufactured by Atotech Japan) [Electroplating conditions] Current density 1 A / dm ² hours 30 minutes Temperature Room temperature

(13) After the plating resist 3 is peeled off and removed with 5% KOH, the electroless plating film 12 under the plating resist 3 is dissolved and removed by etching with a mixed solution of sulfuric acid and hydrogen peroxide. Copper plating film 12 and electrolytic copper plating film 1
A conductor circuit (including the via hole 7) 5 made of 3 and having a thickness of 18 μm was formed. Further, the surface of the interlayer resin insulating layer 2 between the conductor circuits located at the part where the conductor circuits are not formed is immersed in a 70 ° C. solution containing 800 g / l of chromic acid for 3 minutes, and the surface of the interlayer resin insulation layer 2 is etched by 1 μm. The resulting palladium catalyst was removed (see FIG. 6 (d)).

(14) The substrate on which the conductor circuit 5 was formed was coated with copper sulfate (8 g / l), nickel sulfate (0.6 g / l), citric acid (15 g / l), and sodium hypophosphite (29 g / l).
l), an aqueous solution containing boric acid (31 g / l) and a surfactant (Surfynol 465, manufactured by Nissin Chemical Industry Co., Ltd.) (0.1 g / l). After immersion, one minute after immersion, vibrating in the vertical and horizontal directions at a rate of once every 4 seconds, the surface of the land of the lower conductor circuit and the through-hole was roughened with a needle-like alloy made of Cu-Ni-P. An oxide layer 11 was provided (see FIG. 7A). At this time, the formed roughened layer 11 is converted to an EPMA (X-ray fluorescence analyzer).
As a result, the composition ratio of Cu was 98 mol%, Ni was 1.5 mol%, and P was 0.5 mol%. Further, tin borofluoride (0.1 mol / l), thiourea (1.0 mol / l)
(mol / l) using a plating bath at a temperature of 50 ° C. and a pH of 1.2, and a Cu—Sn substitution reaction was performed to provide a 0.3 μm thick Sn layer on the surface of the roughened layer. However, the Sn layer is not shown.

(15) By repeating the above steps (6) to (14), a conductor circuit of a further upper layer was formed, and a multilayer wiring board was obtained. However, Sn substitution was not performed (see FIGS. 7B to 8B).

(16) Next, a cresol novolak type epoxy resin (manufactured by Nippon Kayaku Co., Ltd.) dissolved in diethylene glycol dimethyl ether (DMDG) so as to have a concentration of 60% by weight was used. 46.67 parts by weight of an oligomer for imparting properties (molecular weight: 4000), 6.67 parts by weight of a bisphenol A type epoxy resin (trade name: Epicoat 1001 manufactured by Yuka Shell Co., Ltd.) dissolved in methyl ethyl ketone, and also bisphenol 6.67 parts by weight of an A-type epoxy resin (manufactured by Yuka Shell Co., trade name: Epicoat E-1001-B80), imidazole curing agent (manufactured by Shikoku Chemicals, trade name: 2E)
4MZ-CN) 1.6 parts by weight, photosensitive monomer 2
Functional acrylic monomer (trade name: R60, manufactured by Nippon Kayaku Co., Ltd.)
4) 4.5 parts by weight, a polyvalent acrylic monomer (manufactured by Kyoei Chemical Co., trade name: DPE6A) 1.5 parts by weight, and a leveling agent composed of an acrylate polymer (manufactured by Kyoei Chemical Co., trade name: Polyflow No.) .75) 0.36 parts by weight was placed in a container, stirred and mixed to prepare a mixed composition, and Irgacure I was used as a photopolymerization initiator for the mixed composition.
-907 (manufactured by Ciba-Geigy) 2.0 parts by weight, 0.2 parts by weight of DETX-S (manufactured by Nippon Kayaku) as a photosensitizer,
By adding 0.6 parts by weight of DMDG, the viscosity was increased to 25.
A solder resist composition adjusted to 1.4 ± 0.3 Pa · s at ℃ was obtained. The viscosity was measured with a B-type viscometer (DVL-B type, manufactured by Tokyo Keiki Co., Ltd.) when the rotor No. was 60 rpm. In the case of 4, 6 rpm, the rotor No. According to 3.

(17) Next, the above-mentioned solder resist composition is applied to both sides of the multilayer wiring board in a thickness of 20 μm,
After performing a drying process under the conditions of 20 ° C. for 20 minutes and 70 ° C. for 30 minutes, a 5 mm-thick photomask on which a pattern of the opening of the solder resist is drawn is brought into close contact with the solder resist layer, and an ultraviolet ray of 1000 mJ / cm ² is applied. Exposure with DM
Development was performed with a TG solution to form an opening having a diameter of 200 μm. Then, at 80 ° C. for 1 hour, and at 100 ° C. for 1 hour.
The solder resist layer was cured by performing heat treatment under the conditions of 120 ° C. for 1 hour and 150 ° C. for 3 hours to form a solder resist pattern layer 14 having an opening and a thickness of 20 μm.

(18) Next, the substrate on which the solder resist layer 14 was formed was replaced with nickel chloride (30 g / l), sodium hypophosphite (10 g / l), and sodium citrate (10 g / l).
g / l) in the electroless nickel plating solution with pH = 5.
This was immersed for 0 minutes to form a nickel plating layer 15 having a thickness of 5 μm in the opening. Further, the substrate was subjected to potassium gold cyanide (2 g / l), ammonium chloride (75 g / l),
It was immersed in an electroless plating solution containing sodium citrate (50 g / l) and sodium hypophosphite (10 g / l) at a temperature of 93 ° C. for 23 seconds to form a 0.03 μm thick nickel plating layer 15 on the nickel plating layer 15. A gold plating layer 16 was formed.

(19) Thereafter, a solder paste is printed in the openings of the solder resist layer 14 and reflowed at 200 ° C. to form solder bumps (solder bodies) 17.
A multilayer wiring printed board having the solder bumps 17 was manufactured (see FIG. 8C).

(Example 2) In the above steps (5) and (14), the substrate after the step (4) or (13) was washed with water and acid-degreased, and then soft-etched. The surface of the lower conductor circuit, the land surface of the through hole and the inner wall were etched by spraying on both surfaces of the substrate to form a roughened surface on the entire surface of the lower conductor circuit. Similarly, a multilayer printed wiring board was manufactured. As an etching solution, 10 parts by weight of an imidazole copper (II) complex, 7 parts by weight of glycolic acid,
A mixture of 5 parts by weight of potassium chloride and 78 parts by weight of ion-exchanged water was used.

Example 3 Basically the same as in Example 1, except that in step (9), instead of 20% by weight of hydrochloric acid, 0.5 mol / l of sodium hydroxide and 0.4 mol
An aqueous solution consisting of 1 / l potassium permanganate was used and immersed at a liquid temperature of 70 ° C. for 5 minutes.

(Example 4) Basically the same as in Example 1, except that in step (9), 20% by weight of nitric acid (trade name: Meckri Mover S) was used instead of 20% by weight of hydrochloric acid. -1020) at 40 ° C.
At a liquid temperature of 5 minutes.

(Example 5) Basically the same as in Example 2, but instead of 20% by weight of hydrochloric acid, 5% by weight of nitric acid and 4% by weight of hydrogen peroxide (hydrogen peroxide concentration: 35%) %), And immersed at a liquid temperature of 30 ° C. for 3 minutes.

Example 6 Basically the same as Example 5, except that tin borofluoride (0.5 mol / l) and thiourea (0.375 mol) were used in the step of forming the coating layer.
/ L), sodium hypophosphite (20 g /
l), polyethylene glycol (10
(00 mg / l) using a tin substitution plating solution at a temperature of 25 ° C. and a Cu-Sn substitution reaction for 60 seconds,
An Sn layer was provided on the surface of the roughened layer.

(Embodiment 7) Basically, it is the same as Embodiment 5, except that the surface of the lower conductor circuit and / or the land surface of the through hole and the inner wall are etched.
In the step of forming a roughened surface on the entire surface of the lower conductive circuit, a roughened surface was formed on the conductive circuit surface using a mixed aqueous solution containing sulfuric acid and hydrogen peroxide solution as an etchant.

(Example 8) Basically the same as in Example 2 except that 5% by weight of hydrofluoric acid and 4% by weight of hydrogen peroxide (hydrogen peroxide concentration: 35%)
And immersed at a liquid temperature of 30 ° C. for 3 minutes.

(Example 9) Preparation of Resin Film for Interlayer Resin Insulation Layer Bisphenol A type epoxy resin (Epoxy equivalent 46
9. Yuka Shell Epoxy Epicoat 1001) 3
0 parts by weight, 40 parts by weight of a cresol novolak type epoxy resin (epoxy equivalent: 215, Epichron N-673 manufactured by Dainippon Ink and Chemicals, Inc.), a triazine structure-containing phenol novolak resin (phenolic hydroxyl group equivalent: 120,
FENOLITE KA-705 manufactured by Dainippon Ink and Chemicals, Inc.
2) 30 parts by weight were dissolved by heating in 20 parts by weight of ethyl diglycol acetate and 20 parts by weight of solvent naphtha while stirring, and epoxidized polybutadiene rubber (Denalex R-45EPT manufactured by Nagase Kasei Kogyo Co., Ltd.) was added thereto.
15 parts by weight, 1.5 parts by weight of a crushed product of 2-phenyl-4,5-bis (hydroxymethyl) imidazole, 2 parts by weight of finely divided silica, and 0.5 part by weight of a silicon-based antifoaming agent are added, and an epoxy resin composition is added. Was prepared. The resulting epoxy resin composition is applied on a 38 μm-thick PET film using a roll coater so that the thickness after drying becomes 50 μm, and then dried at 80 to 120 ° C. for 10 minutes to form an interlayer resin. A resin film for an insulating layer was produced.

B. Preparation of resin filler A resin filler was prepared in the same manner as in Example 1.

C. Manufacturing method of printed wiring board (1) 0.6 mm thick glass epoxy resin or BT
A starting material was a copper-clad laminate in which 18 μm copper foils 8 were laminated on both sides of a substrate 1 made of (bismaleimide triazine) resin (see FIG. 9A). First, the copper-clad laminate was drilled, subjected to an electroless plating treatment, and etched in a pattern to form a lower conductor circuit 4 and a through hole 9 on both surfaces of the substrate 1.

(2) Through hole 9 and lower conductor circuit 4
After the substrate on which was formed was washed with water and dried, NaOH (1
0 g / l), NaClO ₂ (40 g / l), Na ₃ PO
₄ A blackening treatment using an aqueous solution containing (16 g / l) as a blackening bath (oxidizing bath), NaOH (19 g / l), NaB
A reduction treatment was performed using an aqueous solution containing H ₄ (5 g / l) as a reduction bath, and roughened surfaces 4 a and 9 a were formed on the entire surface of the lower conductor circuit 4 including the through holes 9 (see FIG. 9B). ).

(3) After preparing the resin filler described in the above B, within 24 hours after the preparation by the following method, the conductive circuit non-formed portion and the conductive circuit in the through hole 9 and on one side of the substrate 1 A layer of the resin filler 10 was formed on the outer edge portion of No. 4. That is, first, the resin filler was pushed into the through hole using a squeegee, and then dried at 100 ° C. for 20 minutes. Next, a mask having an opening corresponding to the conductive circuit non-forming portion is placed on the substrate, and a layer of the resin filler 10 is formed in the conductive circuit non-forming portion having a concave portion using a squeegee. At 20 ° C. for 20 minutes (FIG. 9).
(C)).

(4) One surface of the substrate after the treatment of the above (3) is subjected to belt sanding using # 600 belt polishing paper (manufactured by Sankyo Rikagaku) 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 caused by the belt sander polishing. Such a series of polishing was similarly performed on the other surface of the substrate. Then, at 100 ° C for 1 hour, at 120 ° C for 3 hours, at 150 ° C
For 1 hour and a heat treatment at 180 ° C. for 7 hours to cure the resin filler 10.

As described above, the surface layer of the resin filler 10 formed in the through-hole 9 and the portion where the conductor circuit is not formed and the surface of the lower conductor circuit 4 are flattened, and the resin filler 10 and the side surfaces of the lower conductor circuit 4 are flattened. 4a is firmly adhered through the roughened surface, and the inner wall surface 9a of the through hole 9 and the resin filler 10
Was firmly adhered through the roughened surface to obtain an insulating substrate (see FIG. 9D). By this step, the resin filler 10
And the surface of the lower conductor circuit 4 are flush with each other.

(5) Next, both surfaces of the substrate 1 on which the lower conductor circuit 4 was formed were softly etched by alkali degreasing, and then an imidazole copper (II) complex 1 was used as an etching solution.
Using a mixture of 0 parts by weight, 7 parts by weight of glycolic acid, 5 parts by weight of potassium chloride and 78 parts by weight of ion-exchanged water, a roughened surface was formed by etching a conductor circuit (see FIG. 10A). ).

(6) Then, tin borofluoride (1.0 mol
1 / l) and thiourea (1.0 mol / l), using a tin displacement plating solution at a temperature of 50 ° C and a pH of 1.2,
Cu-Sn substitution reaction for 2 seconds, and a thickness of 0.
A 3 μm Sn layer was provided. The Sn layer is not shown.

(7) Next, on both surfaces of the substrate, the resin film for an interlayer resin insulating layer prepared in the above A was attached by using a vacuum laminator apparatus by the following method to form an interlayer resin insulating layer ( FIG. 10 (b)). That is,
A resin film for an interlayer resin insulation layer is placed on a substrate, the degree of vacuum is 0.5 Torr, the pressure is 4 kgf / cm ² , and the temperature is 80.
At 60 ° C for 60 seconds.
Heat cured at 300C for 30 minutes.

(8) Next, a CO ₂ gas laser having a wavelength of 10.4 μm is used to form a beam having a beam diameter of 4.0 through a mask having a through hole having a thickness of 1.2 mm formed on the interlayer resin insulating layer 2.
10 mm, a top hat mode, a pulse width of 8.0 μs, a diameter of a through hole of the mask of 1.0 mm, and a one-shot condition, a via hole opening 6 having a diameter of 80 μm was formed in the interlayer resin insulating layer 2 (FIG. c)).

(9) The substrate in which the via hole opening 6 was formed was placed in a 80 ° C. solution containing 60 g / l of permanganate.
The surface of the interlayer resin insulating layer 2 including the inner wall of the via hole opening 6 was roughened by dissolving and removing the epoxy resin particles present on the surface of the interlayer resin insulating layer 2 for 0 minutes (FIG. 10 ( d)).

(10) Next, the substrate after the above-mentioned treatment is mixed with a 5% by weight nitric acid and a 4% by weight aqueous hydrogen peroxide solution (hydrogen peroxide concentration: 35%) at a liquid temperature of 30 ° C. For 3 minutes, the exposed Sn layer on the surface of the conductor circuit 5 was removed by etching, and then immersed in a neutralizing solution (manufactured by Shipley), and then washed with water. The state where the Sn layer is removed is not shown in the drawings. Further, by applying a palladium catalyst (manufactured by Atotech) to the surface of the substrate subjected to the surface roughening treatment, catalyst nuclei were attached to the surface of the interlayer resin insulating layer 2 and the inner wall surface of the via hole opening 6.

(11) Next, the substrate is immersed in an electroless copper plating aqueous solution having the following composition, and has a thickness of 0.6 to 3.
A 0 μm electroless copper plating layer 12 was formed.
(A)). [Electroless plating aqueous solution] NiSO ₄ 0.003 mol / l tartaric acid 0.200 mol / l copper sulfate 0.030 mol / l HCHO 0.050 mol / l NaOH 0.100 mol / l α, α'-bipyridyl 40 mg / l Polyethylene glycol (PEG) 0.10 g / l [Electroless plating conditions] 40 minutes at a liquid temperature of 35 ° C

(12) A commercially available photosensitive dry film was stuck on the electroless copper plating layer 12, a mask was placed thereon, and
Exposure at mJ / cm ² and development treatment with a 0.8% aqueous sodium carbonate solution provided plating resist 3 (see FIG. 11B).

(13) Next, the substrate was washed with water at 50 ° C., degreased, washed with water at 25 ° C., further washed with sulfuric acid, and then subjected to electrolytic copper plating under the following conditions. The layer 13 was formed (see FIG. 11C). [Electroplating aqueous solution] sulfuric acid 2.24 mol / l copper sulfate 0.26 mol / l additive 19.5 ml / l (manufactured by Atotech Japan, Capparaside HL) [electroplating conditions] current density 1 A / dm ² hours 65 minutes Temperature 22 ± 2 ℃

(14) Further, the plating resist 3 is made of 5% Na
After stripping off with an OH aqueous solution, the electroless plating film 12 under the plating resist 3 is dissolved and removed by etching with a mixed solution of sulfuric acid and hydrogen peroxide, and is composed of an electroless copper plating film 12 and an electrolytic plating film 13. Independent upper-layer conductor circuits 5 (including via holes 7) having a thickness of 18 μm were formed. In addition, 8
The surface of the interlayer resin insulating layer 2 between the conductor circuits located in the part where the conductor circuits are not formed is etched by 1 μm by immersing in a 70 ° C. solution containing 00 g / l chromic acid for 3 minutes, and the palladium remaining on the surface is etched. The catalyst was removed (FIG. 11 (d)
reference).

(15) By repeating the above steps (5) to (14), a conductor circuit of a further upper layer was formed, and a multilayer wiring board was obtained (see FIGS. 12A to 13B). .

(16) Next, a cresol novolak type epoxy resin (manufactured by Nippon Kayaku Co., Ltd.) dissolved in diethylene glycol dimethyl ether (DMDG) so as to have a concentration of 60% by weight was used. 46.67 parts by weight of an oligomer for imparting properties (molecular weight: 4000), 15.0 parts by weight of a bisphenol A type epoxy resin (trade name: Epicoat 1001 manufactured by Yuka Shell Co., Ltd.) dissolved in methyl ethyl ketone, and imidazole cured Agent (Shikoku Chemicals, trade name: 2E4MZ-CN)
1.6 parts by weight, 3.0 parts by weight of a polyvalent acrylic monomer (trade name: R604, manufactured by Nippon Kayaku Co., Ltd.), which is a photosensitive monomer, and similarly polyvalent acrylic monomer (trade name: DPE6A, manufactured by Kyoei Chemical Co., Ltd.) 1 0.5 part by weight and 0.71 part by weight of a dispersion antifoaming agent (manufactured by San Nopco Co., S-65) are placed in a container, stirred and mixed to prepare a mixed composition, and photopolymerization of the mixed composition is started. 2.0 parts by weight of benzophenone (manufactured by Kanto Kagaku) and 0.2 parts by weight of Michler's ketone (manufactured by Kanto Kagaku) as a photosensitizer were added, and the viscosity was 1.4 ± 0.3 Pa · s at 25 ° C. A solder resist composition adjusted to the above was obtained. The viscosity was measured using a B-type viscometer (DVL-B type, manufactured by Tokyo Keiki Co., Ltd.) at 60 rpm with rotor N.
o. In the case of 4, 6 rpm, the rotor No. According to 3.

(17) Next, the solder resist composition was applied to both sides of the multilayer wiring board in a thickness of 20 μm,
After drying at 20 ° C. for 20 minutes and at 70 ° C. for 30 minutes, the solder pad pattern is drawn to a thickness of 5 mm.
The photomask of 10
It was exposed to ultraviolet light of 00 mJ / cm ² and developed with a DMTG solution to form an opening having a diameter of 200 μm. And
Further, at 80 ° C. for 1 hour, at 100 ° C. for 1 hour, and at 120 ° C.
For 1 hour and at 150 ° C. for 3 hours to cure the solder resist layer by heating, and have an opening,
A solder resist layer 14 having a thickness of 20 μm was formed. In addition, a commercially available solder resist composition can also be used as the solder resist composition.

(18) Next, sodium persulfate is used as a main component.
Etching solution with an etching ability of about 2 μm per minute
In the etching solution.
The substrate on which the dying layer 14 is formed is immersed for one minute,
Roughened surface with average roughness (Ra) of 1 μm or less is formed on the road surface
did. Further, this substrate was coated with nickel chloride (2.3 × 1).
0^-1mol / l), sodium hypophosphite (2.8 × 1
0^-1mol / l), sodium citrate (1.6 × 10
^-1mol / l) electroless nickel with pH = 4.5
Immerse in a plating solution for 20 minutes, and place a 5 μm
A Kel plating layer 15 was formed. In addition, shear the substrate
Potassium gold (7.6 × 10^-3mol / l), chloride
Nmonium (1.9 × 10^-1mol / l), sodium citrate
Thorium (1.2 × 10^-1mol / l), sodium hypophosphite
Thorium (1.7 × 10^-1mol / l)
Immerse in plating solution at 80 ° C for 7.5 minutes,
Gold plating layer 1 having a thickness of 0.03 μm
6 was formed as a solder pad.

(19) Thereafter, a solder paste was printed in the openings of the solder resist layer 14 and reflowed at 200 ° C. to form the solder bumps 17, thereby manufacturing a multilayer printed wiring board having the solder bumps 17. FIG. 13 (c)).

Example 10 Basically the same as Example 9, except that in step (10), instead of being immersed in a mixture of nitric acid and hydrogen peroxide, 5% by weight of hydrofluoric acid was added. 4
It was immersed for 3 minutes in a mixed solution of 30% by weight of hydrogen peroxide solution (hydrogen peroxide concentration: 35%).

Example 11 Basically the same as Example 9, except that in Step (5), 10 parts by weight of imidazole copper (II) complex, 7 parts by weight of glycolic acid and 5 parts by weight of potassium chloride
The conductor circuit was etched using a mixed solution containing sulfuric acid and a hydrogen peroxide solution instead of an etching solution in which a mixture of 78 parts by weight of ion-exchanged water and 78 parts by weight of ion-exchanged water was mixed.

Example 12 (1) Glass epoxy resin or BT having a thickness of 0.8 mm
A starting material was a copper-clad laminate in which 18 μm copper foils 8 were laminated on both sides of a substrate 1 made of (bismaleimide-triazine) resin (see FIG. 14A). First, this copper-clad laminate is drilled, and then a plating resist is formed. Then, the substrate is subjected to an electroless copper plating treatment to form through holes 9, and the copper foil is patterned in a conventional manner. Then, an inner copper pattern (lower conductive circuit) 4 was formed on both surfaces of the substrate.

(2) The substrate on which the lower conductive circuit 4 is formed is washed with water and dried, and then an etching solution is sprayed on both surfaces of the substrate by spraying, so that the surface of the lower conductive circuit 4, the land surface of the through hole 9, and the inner wall are formed. And by etching
Roughened surfaces 4a and 9a were formed on the entire surface of the lower conductor circuit 4 (see FIG. 14B). As an etching solution, 10 parts by weight of an imidazole copper (II) complex, 7 parts by weight of glycolic acid,
A mixture of 5 parts by weight of potassium chloride and 78 parts by weight of ion-exchanged water was used.

(3) The resin filler 10 containing a cycloolefin resin as a main component is mixed with the through hole 9 by the following method.
A layer of the resin filler 10 was formed inside and on the one-side surface of the substrate 1 where no conductive circuit was formed and on the outer edge of the conductive circuit 4. That is, first, the resin filler was pushed into the through holes using a squeegee, and then dried by heating. Next, a mask having an opening corresponding to the conductive circuit non-forming portion is placed on the substrate, and a layer of the resin filler 10 is formed in the conductive circuit non-forming portion having a concave portion using a squeegee. It was dried (see FIG. 14 (c)).

(4) One surface of the substrate after the treatment of the above (3) is subjected to belt sanding using a belt polishing paper (manufactured by Sankyo Rikagaku Co., Ltd.) to form a surface of the lower conductive circuit 4 and a land surface of the through hole 9. Was polished so that the resin filler 10 did not remain, and then buffed to remove the scratches caused by the belt sander polishing. Such a series of polishing was similarly performed on the other surface of the substrate. Then, the filled resin filler 10 was cured by heating (see FIG. 14D).

In this manner, the surface layer portion of the resin filler 10 filled in the through holes 9 and the like and the roughened layer 4a on the upper surface of the lower conductor circuit 4 are removed to flatten both surfaces of the substrate, and the resin filler 10 and the lower layer are removed. A wiring board was obtained in which the side surfaces of the conductive circuit 4 were firmly adhered through the roughened surface 4a, and the inner wall surface of the through hole 9 was tightly adhered to the resin filler 10 through the roughened surface 9a.

(5) Next, both sides of the substrate 1 on which the lower conductor circuit 4 is formed are alkali-degreased and soft-etched, and then the same etching solution as the etching solution used in the above (2) is sprayed thereon. By etching the surface of the lower conductive circuit 4 once flattened and the land surface of the through hole 9, the roughened surface 4 is formed on the entire surface of the lower conductive circuit 4.
a and 9a were formed (see FIG. 15A).

(6) Then, tin borofluoride (1.0 mol
1 / l) and thiourea (1.0 mol / l), using a tin displacement plating solution at a temperature of 50 ° C and a pH of 1.2,
Cu-Sn substitution reaction for 2 seconds, and a thickness of 0.
A 3 μm Sn layer was provided. The Sn layer is not shown.

(7) Next, on both surfaces of the substrate having undergone the above steps,
A pressure of 5 kg / c while heating a thermosetting type cycloolefin resin sheet having a thickness of 50 μm to a temperature of 50 to 150 ° C.
Vacuum compression lamination was performed at m ² to provide an interlayer resin insulating layer 2 made of a cycloolefin-based resin (see FIG. 15B). The degree of vacuum during vacuum compression was 10 mmHg.

(8) Next, using a CO ₂ gas laser having a wavelength of 10.4 μm, a cycloolefin resin was obtained under the conditions of a beam diameter of 5 mm, a top hat mode, a pulse width of 50 μsec, a mask hole diameter of 0.5 mm, and three shots. A via hole opening 6 having a diameter of 80 μm was provided in the interlayer resin insulation layer 2 made of (see FIG. 15C). Thereafter, a desmear treatment was performed using oxygen plasma.

(9) Next, SV manufactured by Japan Vacuum Engineering Co., Ltd.
The surface of the interlayer resin insulating layer 2 was roughened by performing a plasma treatment using −4540 (see FIG. 15D). On this occasion,
Argon gas is used as the inert gas, and power 200
Plasma treatment was performed for 2 minutes under the conditions of W, gas pressure 0.6 Pa, and temperature 70 ° C.

(10) Next, the substrate having been subjected to the above treatment is mixed with a solution of 5% by weight of nitric acid and 4% by weight of hydrogen peroxide (hydrogen peroxide concentration: 35%) at a temperature of 30 ° C. For 3 minutes, the exposed Sn layer on the surface of the conductor circuit 5 was removed by etching, and then immersed in a neutralizing solution (manufactured by Shipley), and then washed with water. The state where the Sn layer is removed is not shown in the drawings. Further, the above step (9)
After replacing the argon gas inside using the same apparatus as used in the above, sputtering using a Ni—Cu alloy as a target was performed at a pressure of 0.6 Pa, a temperature of 80 ° C., and a power of 200.
The process was performed under the condition of W for 5 minutes to form a Ni—Cu alloy layer 12 on the surface of the polyolefin-based interlayer resin insulating layer 2.
At this time, the thickness of the formed Ni—Cu alloy layer 12 was 0.2 μm (see FIG. 16A).

(11) A commercially available photosensitive dry film was stuck on both surfaces of the substrate after the above treatment, a photomask film was placed, and after exposure at 100 mJ / cm ² ,
It was developed with 0.8% sodium carbonate to form a pattern of the plating resist 3 (see FIG. 16B).

(12) Next, electrolytic copper plating was performed under the following conditions to form an electrolytic copper plating film 13 (see FIG. 16C). This means that the electrolytic copper plating film 13 has been used to thicken the portion that will become the conductor circuit 5 and fill the portion that will become the via hole 7 with plating in the later-described steps.
The additive in the electroplating aqueous solution is Capparaside HL manufactured by Atotech Japan.

[Electroplating aqueous solution] sulfuric acid 2.24 mol / l copper sulfate 0.26 mol / l additive 19.5 ml / l [electroplating conditions] current density 1 A / dm ² hours 65 minutes temperature 22 ± 2 ° C

(13) Then, the plating resist 3 is made of 5% Na
After stripping and removing with OH, the Ni-Cu alloy layer 12 existing under the plating resist 3 is dissolved and removed by an etching process using a mixed solution of nitric acid, sulfuric acid and hydrogen peroxide to form an electrolytic copper plating film. The conductor circuit 5 (including the via hole 7) having a thickness of 18 μm and made of 13 or the like was formed (FIG. 16)
(D)).

(14) Subsequently, the above steps (5) to (13) were repeated to form a further upper layer conductive circuit.
(See FIGS. 16A and 16B).

(15) Next, the viscosity was adjusted to 2 in the same manner as in Example 9.
A solder resist composition adjusted to 1.4 ± 0.3 Pa · s at 5 ° C. was obtained, and a solder resist layer 14 having an opening and a thickness of 20 μm was formed in the same manner as in Example 9.
Was formed.

(16) Next, the substrate on which the solder resist layer 14 was formed was coated with nickel chloride (2.3 × 10 ^-1 mol / mol).
l), sodium hypophosphite (2.8 × 10 ⁻¹ mol /
l), sodium citrate (1.6 × 10 ⁻¹ mol /
2) in the electroless nickel plating solution having pH = 4.5 containing l)
This was immersed for 0 minutes to form a nickel plating layer 15 having a thickness of 5 μm in the opening. Furthermore, the substrate gold potassium cyanide ^{(7.6 × 10 -3 mol / l} ), ammonium chloride ^{(1.9 × 10 -1 mol / l} ), sodium citrate (1.2 × 10 ^-1 mol / l), immersed in an electroless plating solution containing sodium hypophosphite (1.7 × 10 ^-1 mol / l) at 80 ° C. for 7.5 seconds to form a layer having a thickness of 0 A 0.03 μm gold plating layer 16 was formed to form a solder pad.

(17) Thereafter, a solder paste is printed in the openings of the solder resist layer 14 and reflowed at 200 ° C. to form the solder bumps 17, thereby manufacturing a multilayer printed wiring board having the solder bumps 17 ( FIG. 16 (c)).

(Example 13) Basically the same as Example 12, except that in Step (10), instead of immersion in a mixture of nitric acid and hydrogen peroxide, 5% by weight hydrofluoric acid was added. It was immersed for 3 minutes in a mixed solution of 4% by weight of hydrogen peroxide solution (hydrogen peroxide concentration: 35%) at a liquid temperature of 30 ° C.

(Example 14) Basically the same as Example 12, except that in step (5), imidazole copper (II)
Instead of an etching solution in which 10 parts by weight of a complex, 7 parts by weight of glycolic acid, 5 parts by weight of potassium chloride, and 78 parts by weight of ion-exchanged water are mixed, a conductor circuit is formed by using a mixed solution containing sulfuric acid and hydrogen peroxide. Etched.

(Comparative Example 1) In the above step (9),
A multilayer printed wiring board was manufactured in the same manner as in Example 1 except that the n-layer was not removed by etching.

The multilayer printed wiring boards of Examples 1 to 14 and Comparative Example 1 manufactured as described above were subjected to -55 ° C.
, And a heat cycle test in which a heat cycle of holding at 125 ° C. for 30 minutes was repeated 1,000 times was performed, and the connection of via holes and the presence or absence of a coating layer were examined by cross-cutting and microscopic observation. As a result, in the multilayer printed wiring boards according to Examples 1 to 14,
In all of the devices manufactured under the same conditions, the via holes were firmly connected to the rough surface of the lower conductive circuit, and no peeling or the like was observed at all. However, in the multilayer printed wiring board according to Comparative Example 1, some of the via holes were partially connected. Peeling was observed at the connection between the via hole and the lower conductor circuit. Further, Examples 1 to
In the fourteenth multilayer printed wiring board, the entire Sn layer in the via hole opening was removed.

Furthermore, the continuity test was performed on the printed wiring boards of Examples 1 to 14 and Comparative Example 1 to measure the rate of change in resistance. The multilayer printed wiring boards of Examples 1 to 14 were the same as those of Comparative Example 1. The rate of change in resistance was lower than that of the wiring board, and the electrical characteristics were excellent.

In the examples of the present specification, the case where tin is used as the metal forming the coating layer is described. However, the case where another metal (Pd) is used as the metal forming the coating layer is described. Also, the same effect as in the case of using tin was observed. Further, Ag is used as a metal for forming the coating layer.
In the case of using, a part of the coating layer where the via hole was formed was not removed entirely, and only a part of the coating layer where the via hole was formed was removed. The connection reliability and the electrical connection of these were superior to those without the coating layer removed at all.

[0219]

As described above, according to the method for manufacturing a printed wiring board of the present invention, it is possible to manufacture a multilayer printed wiring board in which connection reliability of via holes is ensured even under severe conditions.

[Brief description of the drawings]

FIG. 1A is a cross-sectional view showing a part of a multilayer printed wiring board manufactured by using the manufacturing method of the present invention;
(B) is a conceptual diagram showing a shape in a via hole opening of a multilayer printed wiring board manufactured by using the manufacturing method of the present invention.

FIG. 2A is a cross-sectional view showing a part of a multilayer printed wiring board manufactured by using the manufacturing method of the present invention;
(B) is a conceptual diagram showing a shape in a via hole opening of a multilayer printed wiring board manufactured by using the manufacturing method of the present invention.

FIG. 3A is a cross-sectional view showing a part of a multilayer printed wiring board manufactured by using the manufacturing method of the present invention;
(B) is a conceptual diagram showing a shape in a via hole opening of a multilayer printed wiring board manufactured by using the manufacturing method of the present invention.

FIGS. 4A to 4D are cross-sectional views illustrating a part of the manufacturing process of the multilayer printed wiring board according to the present invention.

FIGS. 5A to 5D are cross-sectional views showing a part of the manufacturing process of the multilayer printed wiring board of the present invention.

FIGS. 6A to 6D are cross-sectional views showing a part of the manufacturing process of the multilayer printed wiring board of the present invention.

FIGS. 7A to 7C are cross-sectional views showing a part of the manufacturing process of the multilayer printed wiring board of the present invention.

FIGS. 8A to 8C are cross-sectional views showing a part of the manufacturing process of the multilayer printed wiring board according to the present invention.

FIGS. 9A to 9D are cross-sectional views showing a part of the manufacturing process of the multilayer printed wiring board of the present invention.

FIGS. 10A to 10D are cross-sectional views illustrating a part of the manufacturing process of the multilayer printed wiring board according to the present invention.

FIGS. 11A to 11D are cross-sectional views illustrating a part of the manufacturing process of the multilayer printed wiring board according to the present invention.

FIGS. 12A to 12C are cross-sectional views showing a part of the manufacturing process of the multilayer printed wiring board of the present invention.

FIGS. 13A to 13C are cross-sectional views illustrating a part of the manufacturing process of the multilayer printed wiring board according to the present invention.

FIGS. 14A to 14D are cross-sectional views illustrating a part of the manufacturing process of the multilayer printed wiring board according to the present invention.

FIGS. 15A to 15D are cross-sectional views showing a part of the manufacturing process of the multilayer printed wiring board of the present invention.

16 (a) to (d) are cross-sectional views showing a part of the manufacturing process of the multilayer printed wiring board of the present invention.

17 (a) to (c) are cross-sectional views showing a part of the manufacturing process of the multilayer printed wiring board of the present invention.

FIGS. 18A to 18C are cross-sectional views illustrating a part of the 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) 4 lower conductive circuit 4a roughened surface 5 upper conductive circuit 7 via hole 8 copper foil 9 through hole 9a roughened surface 10 resin filler 14 solder resist layer ( Organic resin insulating layer) 15 Nickel plating film 16 Gold plating film 17 Solder bump

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Toru Nakai 1-1, Ibikawa-cho, Ibi-gun, Gifu Prefecture Inside Ibiden Co., Ltd. (72) Inventor Yasuhiro Okuda 1-1, Ibigawa-cho, Kitakata, Ibi-gun, Gifu Prefecture Ibiden Co., Ltd. (72) Inventor Isao Sugiura 1-1 North of Ibigawa-cho, Ibi-gun, Gifu Prefecture F-term (reference) 5E343 AA02 AA15 AA17 BB24 BB34 BB35 BB71 CC03 CC06 CC08 CC33 CC34 CC35 CC36 CC38 CC43 CC44 CC48 CC52 CC62 CC67 CC73 CC74 CC78 DD23 DD25 DD34 DD35 DD36 DD44 DD46 DD47 DD48 DD76 EE02 EE22 EE52 EE53 ER02 ER12 GG13 5E346 AA06 AA12 AA15 AA26 AA32 AA35 AA43 AA51 AA54 BB01 BB16 CC02 CC04 CC08 DD33 DD33 DD33 EE38 FF02 FF03 FF07 FF13 FF15 GG15 GG16 GG17 GG18 GG19 GG22 GG23 GG25 GG27 HH05

Claims (7)

[Claims] A roughened surface is formed on a conductive circuit by performing a roughening process after a conductive circuit is formed, and a coating layer made of metal is formed on the roughened surface or the roughened layer. And further comprising a step of forming a via hole opening after covering the conductor circuit having the coating layer with an interlayer resin insulating layer, thereby forming a plurality of layers with the interlayer resin insulating layer interposed on the insulating substrate. In the method of manufacturing a multilayer printed wiring board for forming a conductor circuit, after forming an opening for a via hole in the interlayer resin insulating layer, forming a coating layer on the roughened surface or the roughened layer exposed from the opening for the via hole. A method for manufacturing a multilayer printed wiring board, wherein at least a part of the multilayer printed wiring board is removed. 2. The method for manufacturing a multilayer printed wiring board according to claim 1, wherein the coating layer formed on the roughened surface or the roughened layer is made of a metal or a noble metal having an ionization tendency greater than copper and equal to or less than titanium. 3. The roughened surface or the coating layer of the roughened layer exposed from the via hole opening is removed by etching using an alkaline solution containing 1 to 40% by weight of an acid or an oxidizing agent. The method for manufacturing a multilayer printed wiring board according to claim 1. 4. A roughening surface or a roughening layer coating layer exposed from the via hole opening is removed by etching using a mixed solution of 1 to 40% by weight of an acid and a peroxide. The method for manufacturing a multilayer printed wiring board according to claim 1. 5. The method according to claim 1, wherein the acid is hydrochloric acid, nitric acid, sulfuric acid, hydrofluoric acid,
The method for producing a multilayer printed wiring board according to claim 3 or 4, wherein the method is at least one selected from the group consisting of phosphoric acid and formic acid. 6. An interlayer resin insulating layer is formed on a substrate having a roughened surface on which a conductor circuit having a metal coating layer is formed on the roughened surface. A via hole opening is formed, and further, in a multilayer printed wiring board having a via hole formed by forming a conductor layer in the via hole opening, a conductor circuit portion in the via hole opening is formed of the metal. A multilayer printed wiring board, wherein at least a part of a coating layer is removed, and the roughened surface is directly connected to the conductor layer. 7. The multilayer printed wiring board according to claim 6, wherein the metal coating layer is made of a metal or a noble metal having an ionization tendency higher than copper and equal to or lower than titanium.