JPH0734505B2 - Multilayer printed wiring board and manufacturing method thereof - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a multilayer printed wiring board and a method for manufacturing the same, and in particular, the present invention is electrically insulated by a resin insulating layer made of a heat resistant resin. The present invention relates to a multilayer printed wiring board having a conductor circuit composed of a plurality of electroless plated films and a method for manufacturing the same.

[Conventional technology]

2. Description of the Related Art In recent years, with the progress of electronic technology, higher densities and higher speeds of arithmetic functions have been promoted for electronic devices such as large computers. As a result, multilayer printed wiring boards in which wiring circuits are formed in multiple layers have also been spotlighted for the purpose of increasing the density of printed wiring boards.

Conventionally, as a multilayer printed wiring board, for example, a multilayer printed wiring board in which a plurality of circuit boards each having an internal circuit formed thereon are laminated and pressed by using a prepreg as an insulating layer and then each internal circuit is connected by a through hole so as to be electrically connected is representative. It was a thing.

However, in such a multilayer printed wiring board, since a plurality of internal circuits are connected and conducted through through holes, the wiring circuits become too complicated and it is difficult to realize high density or high speed. Met.

As a multilayer printed wiring board capable of overcoming such problems, a multilayer printed wiring board in which conductor circuits and organic insulating films are alternately built up has been developed recently. This multilayer printed wiring board is suitable for ultra-high density and high speed, but the drawback is that it is difficult to reliably form an electroless plated film on an organic insulating film. For this reason, in such a multilayer printed wiring board, a conductor circuit was formed by a PVD method such as vapor deposition or sputtering or a combined method of the PVD method and electroless plating. The forming method has the drawbacks of low productivity and high cost.

[Problems to be Solved by the Invention]

The inventors of the present invention have conducted various studies for the purpose of eliminating the drawbacks of the conventional multilayer printed wiring board as described above, and previously disclosed a multilayer printed wiring board and a manufacturing method thereof according to JP-A-63-126297. Suggested an invention.

However, in the multilayer printed wiring board according to the invention proposed prior to this invention, the anchor tends to become unclear unless there is a significant difference in the solubility of the particulate matter and the matrix resin in a specific chemical solution. As a result, there remains a problem to be solved that the adhesion of the plating film does not increase.

An object of the present invention is to solve the problems of the above-mentioned multilayer printed wiring board manufacturing technique previously proposed by the present inventors, and to provide a plurality of electroless plating films electrically insulated by a resin insulating layer made of a heat-resistant resin. The present invention provides a multilayer printed wiring board having a conductor circuit consisting of (3), in which an electroless plated film is formed with high reliability, easily and at low cost.

[Means for Solving the Problems]

Now, the problems of the prior invention that the present inventors have proposed prior to this invention, in the resin insulating layer, a mixture of heat-resistant resin particles and heat-resistant resin fine powder, the surface of the heat-resistant resin particles Advantageously, the inclusion of pseudo particles obtained by adhering at least one of heat-resistant resin fine powder or inorganic fine powder having an average particle size, and agglomerated particles obtained by aggregating heat-resistant resin fine powder makes it possible to eliminate the problem. It turns out that I can do it. That is, the present invention relates to a multilayer printed wiring board in which a plurality of conductor circuits obtained by electroless plating are electrically insulated by a resin insulating layer made of a heat-resistant resin, wherein the resin insulating layer is an oxidizer. On the other hand, a mixture of heat-resistant resin particles having an average particle size of 2 to 10 μm and fine powder of heat-resistant resin having an average particle size of 2 μm or less in a hardly soluble heat-resistant resin, an average particle size of 2
Particles having an average particle size of at least one of heat-resistant resin fine powder having an average particle size of 2 μm or less or inorganic fine powder having an average particle size of 2 μm or less attached to the surface of heat-resistant resin particles of ˜10 μm At least one selected from agglomerated particles obtained by aggregating a heat-resistant resin fine powder having a particle size of 2 μm or less to an average particle size of 2 to 10 μm; that is, a heat-resistant particle soluble in an oxidizing agent. The resin insulating layer electroless plated film forming surface is provided with a concave portion for forming an anchor of the electroless plated film on the portion of the heat resistant particles that are dissolved and removed by the treatment with an oxidizing agent. A multilayer printed wiring board, which is characterized by being provided with.

For the multilayer printed wiring board, a photosensitive resin is suitable as the heat-resistant resin that is poorly soluble in an oxidant, and the heat-resistant resin that is poorly soluble in an oxidant is epoxy. At least one selected from resins, epoxy-modified polyimide resins, polyimide resins and phenol resins is used, and the heat-resistant resin particles are 100 weight parts of the heat-resistant resin solid content that is hardly soluble in an oxidizing agent. 5 to 350 parts by weight with respect to 10 parts by weight, at least one selected from chromic acid, chromate salts, permanganate, and ozone is used as the oxidizing agent, and the electroless material is used. As the plating film, at least one of electroless copper plating film, electroless nickel plating film, and electroless gold plating film is used.

Such a printed wiring board is mainly manufactured by the following steps: (a) An average particle size of 2 to 10 μm for a heat resistant resin that is hardly soluble in an oxidizer on a substrate on which a conductor circuit is formed. Mixture of heat-resistant resin particles and heat-resistant resin fine powder having an average particle diameter of 2 μm or less, heat-resistant resin fine powder having an average particle diameter of 2 μm or less or average particle diameter on the surface of the heat-resistant resin particles having an average particle diameter of 2 to 10 μm Of pseudo particles formed by adhering at least one of inorganic fine powders of 2 μm or less, or aggregated particles of heat resistant resin fine powder having an average particle size of 2 μm or less and having an average particle size of 2 to 10 μm Forming at least one resin insulating layer in which heat-resistant particles soluble in an oxidizing agent are dispersed: (b) surface portion of each resin insulating layer Exists in The step of dissolving and removing only the heat-resistant particles using an oxidizing agent to roughen the surface on the side where the electroless plating film is formed: (c) electroless plating on the roughened resin insulation layer. The process of forming a conductor circuit by applying: is performed.

In the above manufacturing method, the heat-resistant resin that is poorly soluble in an oxidizing agent is preferably a photosensitive resin, and as the heat-resistant resin that is poorly soluble in an oxidizing agent, an epoxy resin or an epoxy-modified polyimide is used. At least one selected from a resin, a polyimide resin, and a phenol resin is suitable, and the heat-resistant particles are 5 to 100 parts by weight of a heat-resistant resin solid content that is hardly soluble in the oxidizing agent. 350 parts by weight are blended, and the oxidizer contains at least one selected from chromic acid, chromate salts, permanganate salts, and ozone, and the electroless plating film is At least one of an electroless copper plating film, an electroless nickel plating film, and an electroless gold plating film is used.

[Action]

 Hereinafter, the present invention will be described in detail.

The multilayer printed wiring board of the present invention is a multilayer printed wiring board having a conductor circuit composed of a plurality of electroless plated films electrically insulated by a resin insulating layer made of a heat resistant resin.

The reason why the conductor circuit of the multilayer printed wiring board is required to be an electroless plating film is that the conductor circuit forming method by electroless plating is easy for mass production and is suitable for high-density wiring.

Further, the reason why the conductor circuit is required to be electrically insulated by the resin insulating layer made of the heat resistant resin is that the resin insulating layer made of the heat resistant resin has a low dielectric constant and a large film thickness. This is because it is easy and suitable for speeding up.

The resin insulating layer made of the heat-resistant resin of the present invention is extremely important to have excellent adhesion with the electroless plating film, and the resin insulating layer is a heat-resistant resin that is hardly soluble in an oxidant. A mixture of heat-resistant resin particles having an average particle diameter of 2 to 10 μm and heat-resistant resin fine powder having an average particle diameter of 2 μm or less, the average particle diameter of 2 μ on the surface of the heat-resistant resin particles having an average particle diameter of 2 to 10 μm.
m or less heat-resistant resin fine powder or pseudo fine particles formed by adhering at least one kind of inorganic fine powder having an average particle size of 2 μm or less, or heat-resistant resin fine powder having an average particle size of 2 μm or less Contains at least one kind of heat-resistant particles selected from agglomerated particles formed by aggregating so as to be 2 to 10 μm (however, the heat-resistant particles are soluble in an oxidant). , And the surface of the resin insulating layer on the side where the electroless plated film is formed has a recess formed as a result of the heat resistant particles being dissolved by an oxidizing agent, and this recess is a part of the electroless plated film. It must act as an anchor.

That is, the resin insulation layer made of the heat-resistant resin according to the present invention is soluble in the oxidant in the heat-resistant resin hardly soluble in the oxidant containing heat-resistant particles soluble in the oxidant. The heat-resistant particles are included. Since the heat-resistant particles and the heat-resistant resin forming the matrix have a large difference in solubility in an oxidizing agent, when the resin insulating layer is treated with an oxidizing agent, it is dispersed on the surface portion of the resin insulating layer. Soluble heat-resistant particles are mainly dissolved and removed, thereby forming a clear anchor,
The surface of the resin insulation layer is uniformly roughened. As a result, high adhesion strength and reliability with the electroless plated film can be obtained.

The heat-resistant particles used in the present invention have an average particle size of 2
A mixture of heat-resistant resin particles having an average particle diameter of 2 to 10 μm and heat-resistant resin fine particles having an average particle diameter of 2 μm or less, or heat-resistant resin fine powder having an average particle diameter of 2 μm or less on the surface of the heat-resistant resin particles having an average particle diameter of 2 to 10 μm or The pseudo particles formed by adhering at least one kind of inorganic fine powder having an average particle diameter of 2 μm or less, and the heat-resistant resin fine powder having an average particle diameter of 2 μm or less have an average particle diameter of 2 to 2.
At least one selected from agglomerated particles aggregated to have a particle size of 10 μm. The reason for using such particles is that the shape of the anchor to be formed can be made extremely complicated by using these particles or a mixture as heat resistant particles.
In particular, it is more preferable to use the mixture as the heat resistant particles.

Here, of the heat resistant particles, the size of the pseudo particles, the agglomerated particles, and the heat resistant resin particles in the mixture is 2 as an average particle size.
The reason for using a size of ~ 10 μm is that the average particle size is 10
If it is larger than μm, the density of anchors formed by dissolution and removal associated with the oxidation treatment tends to be low and the anchors are likely to be non-uniform. As a result, the adhesion strength of the plating film deteriorates, the reliability of the product decreases, and the irregularities on the surface of the adhesive layer become excessively large, making it difficult to obtain a fine conductor pattern. This is because inconvenience is likely to occur in mounting. On the other hand, if the average particle size is smaller than 2 μm, the anchor is likely to be unclear. More preferably, the size of 3 to 8 μm is suitable.

On the other hand, it is necessary to make the adhered fine powder of the pseudo particles, the heat resistant resin fine powder constituting the agglomerated particles and the heat resistant resin fine powder in the mixture have an average particle size of 2 μm or less. The reason for this is that if it is larger than 2 μm, the anchor effect is lowered and the adhesion strength of the plating film is deteriorated.
The size of 0.8 μm or less is more preferable.

Further, the particle size of the pseudo particles, the agglomerated particles and the heat resistant resin particles in the mixture, the particle size of the adhered fine powder of the pseudo particles, the heat resistant resin fine powder constituting the agglomerated particles and the heat resistant resin fine powder in the mixture Advantageously, it is more than double.

Now, the heat-resistant particles are excellent in heat resistance and electric insulation,
Resins that are stable to chemicals other than oxidants and that are hardened by heat treatment to make them insoluble in heat-resistant resin liquids or solvents but soluble in oxidants It is necessary to use.

As the resin constituting such heat-resistant particles, for example, at least one selected from epoxy resin, polyester resin, and bismaleimide-triazine resin
Seeds are used. Among them, the epoxy resin is excellent in characteristics and is most suitable. As the inorganic fine powder soluble in the oxidizing agent, for example, calcium carbonate can be used.

As the oxidant, chromic acid, chromate, permanganate, ozone, etc. are used.

The heat-resistant resin particles having an average particle diameter of 2 to 10 μm and the average particle diameter 2
The mixture with the heat-resistant resin fine powder having a particle diameter of 2 μm or less makes the content of the heat-resistant resin fine powder having an average particle diameter of 2 μm or less 50 to 85% by weight in order to make the shape of the anchor to be extremely complicated. Preferably.

Next, the heat resistant resin constituting the above matrix will be described. This resin is preferably a photosensitive resin, and is excellent in heat resistance, electrical insulation, chemical stability, and adhesiveness, and becomes hard to be soluble in an oxidant when cured. Is advantageous. For example, at least one selected from an epoxy resin, an epoxy-modified polyimide resin, a polyimide resin, and a phenol resin is used.

The reason why it is preferable to use a photosensitive resin as the heat-resistant resin forming the matrix is that a via hole for connecting the conductor layers is easily formed by exposing a predetermined portion, then developing and etching. Because you can

Even if the resin forming the heat-resistant particles and the heat-resistant resin forming the matrix are the same type of resin, if the ones having different solubilities with respect to the oxidizing agent are used, the effect of the present invention can be exhibited. be able to.

The blending amount of the heat-resistant particles with respect to the heat-resistant resin constituting the matrix, relative to 100 parts by weight of the heat-resistant resin constituting the matrix, it is advantageous that it is in the range of 2 to 350 parts by weight, particularly 5 to 200 The range of parts by weight is suitable for increasing the adhesion strength between the resin insulating layer and the electroless plated film. If the blending amount of the heat resistant particles is less than 2 parts by weight, the density of the anchor formed by dissolution and removal is low, and sufficient adhesion strength between the resin insulating layer and the electroless plated film cannot be obtained. On the other hand, when the amount is more than 350 parts by weight, most of the surface of the resin insulating layer is dissolved and removed, and it becomes difficult to form a clear anchor.

Next, the method for manufacturing the multilayer printed wiring board of the present invention will be specifically described.

According to the present invention, first, a resin insulating layer in which heat-resistant particles soluble in an oxidant are dispersed in a heat-resistant resin that is hardly soluble in the oxidant is formed on a substrate on which a conductor circuit is formed. Begins with.

As a method of forming the resin insulation layer on the substrate on which the conductor circuit is formed, for example, in an uncured photosensitive resin whose characteristics after curing are poorly soluble in an oxidant, a heat resistance that is soluble in the oxidant is used. A method of applying a mixed solution in which the functional particles are dispersed, or a method of applying a resin film obtained by processing the mixed solution into a film can be applied. Examples of the coating method include a roller coating method, a dip coating method,
Various means such as a spray coating method, a spinner coating method, a curtain coating method and a screen printing method can be applied.

Each of the heat-resistant resins forming the heat-resistant particles soluble in the oxidizing agent is hardened.
The heat-resistant resin that constitutes the heat-resistant particles is limited to the one that has been subjected to the curing treatment. When an uncured resin is used, the heat-resistant resin liquid that forms the matrix or the heat-resistant resin that forms this matrix is used. When added to a solution dissolved using a solvent, the heat-resistant resin constituting the heat-resistant particles also dissolves in the heat-resistant resin solution or solution, and it is impossible to exert the function as the heat-resistant particles. Because it will be possible.

Particles and fine powder of the heat-resistant resin that constitutes such heat-resistant particles are, for example, heat-resistant resin, and then crushed using a jet mill or a freeze pulverizer, or heat-resistant resin before hardening treatment. It is produced by classifying particles obtained by spray-drying the solution and then curing it, or by adding an aqueous solution curing agent to an uncured heat-resistant resin emulsion and stirring the mixture with a wind classifier or the like.

As a method for curing the heat-resistant resin constituting the heat-resistant particles, there are a method of curing by heating and a method of curing by adding a catalyst. Among them, the method of curing by heat is practical. .

Of the heat-resistant particles, at least one of heat-resistant resin fine powder or inorganic fine powder is formed on the surface of the heat-resistant resin particles.
As a method of forming pseudo particles by attaching seeds, for example, after sprinkling the heat-resistant resin fine powder or the inorganic fine powder on the surface of the heat-resistant resin particles, heating and fusion bonding, or via a binder It is advantageous to apply a bonding method.

Among the heat-resistant particles, as a method for aggregating particles obtained by aggregating the heat-resistant resin fine powder, for example, the heat-resistant resin fine powder, simply heated with a hot air dryer, or add various binders, Aggregate by mixing and drying. Then, after that, it is advantageous to crush by using a ball mill, an ultrasonic disperser or the like, and further classify by a wind force classifier or the like to manufacture.

The shape of the heat-resistant particles thus obtained is not only spherical, but also various complicated shapes, and therefore the shape of the anchor formed thereby also has a complicated shape accordingly, the peel strength, It effectively acts to improve the adhesion strength of the plating film such as pull strength.

The heat-resistant particles produced as described above are mixed by adding a heat-resistant resin liquid that forms a matrix or a solution in which the heat-resistant resin that forms the matrix is dissolved using a solvent, and uniformly dispersing it. A liquid is produced.

As the heat-resistant resin liquid to which the heat-resistant particles are added, a heat-resistant resin liquid containing no solvent can be used as it is, but a heat-resistant resin liquid obtained by dissolving a heat-resistant resin in a solvent has a low viscosity. Therefore, the heat-resistant particles can be easily dispersed uniformly and can be easily applied to the substrate having the conductor layer, so that the heat-resistant particles can be advantageously used. As the solvent used to dissolve the heat-resistant resin, a common solvent, for example, methyl ethyl ketone, methyl cellosolve, ethyl cellosolve,
Butyl carbitol, butyl cellulose, tetralin,
Dimethylformaldehyde, normal methylpyrrolidone, etc. can be used.

The suitable thickness of the resin insulating layer in the present invention is usually 20 ~
Although it is about 100 μm, it can be made thicker if a particularly high insulating property is required.

The resin insulation layer is usually provided with via holes for connecting the conductor layers. As a method of forming this via hole, a method of using a photosensitive resin as a heat-resistant resin forming a matrix, exposing at a predetermined portion, and then developing and etching is preferable. Alternatively, a via hole is formed by laser processing. It is also possible to apply the method of forming. The method of forming via holes by laser processing can be applied either before or after roughening the surface of the resin insulating layer.

As the substrate used in the present invention, for example, a plastic substrate, a ceramic substrate, a metal substrate, a film substrate or the like can be used, and specifically, a glass epoxy substrate, a glass polyimide substrate, an alumina substrate, a low temperature firing ceramic substrate, a nitride substrate. An aluminum substrate, an aluminum substrate, an iron substrate, a polyimide film substrate, or the like can be used.

Next, the heat resistant particles existing on the surface portion of the resin insulating layer are dissolved and removed using an oxidizing agent. As the method of dissolving and removing, it is possible to apply a method of immersing the substrate on which the resin insulating layer is formed in a liquid of an oxidizing agent, or spraying an oxidizing agent on the surface of the resin insulating layer. As a result, the surface of the resin insulating layer can be roughened. For the purpose of effectively removing the heat-resistant particles by dissolution, it is advantageous to lightly remove the surface portion of the resin insulating layer in advance by means of polishing or liquid honing using, for example, a fine powder abrasive. is there.

The multilayer printed wiring board of the present invention is manufactured by roughening the surface of the resin insulating layer and then performing electroless plating on the roughened surface to form a conductor circuit. This electroless plating method includes, for example, electroless copper plating, electroless nickel plating, electroless tin plating, electroless gold plating, electroless silver plating, and the like, in particular electroless copper plating, electroless nickel plating, It is preferable that it is at least one kind of electrolytic gold plating. In addition, it is also possible to perform different types of electroless plating or electroplating on top of the above electroless plating, or to coat solder.

In addition, according to the present invention, a conductor circuit can be formed by various methods that have been performed for conventionally known printed wiring boards. For example, a method of performing electroless plating on a substrate and then etching the circuit, A method of directly forming a circuit when performing electrolytic plating can be applied.

〔Example〕

Examples for manufacturing the multilayer printed wiring board of the present invention will be described below.

Example 1 (1) A glass epoxy copper clad laminate (Toshiba Chemical, trade name: Toshiba Tecolite MEL-4) is laminated with a photosensitive dry film (DuPont, trade name: Liston 1051) to form a desired conductor circuit pattern. The image was printed by exposing it to ultraviolet light through a mask film on which was drawn. Then 1-
After developing with 1-1-trichloroethane and removing the copper in the non-conductor portion using a cupric chloride etching solution, the dry film was peeled off with methylene chloride. As a result, the first-layer conductor circuit 1 including a plurality of conductor patterns on the substrate 2
A wiring board having ... Is formed.

(2) 200 g of epoxy resin particles (Toray, Trepearl EP-B, average particle size 3.9 μm) were dispersed in 5 l of acetone into an epoxy resin particle suspension, and a Henschel mixer (Mitsui Miike Kakoki, FM10B) was used. Epoxy resin powder (manufactured by Mitsui Petrochemical, trade name, TA-1800) dissolved in acetone at a ratio of 30 g per 1 part of acetone while stirring in an epoxy resin powder (Toray, Trepal EP- B, an average particle size of 0.5 μm) 300 g of a dispersion liquid was added dropwise to adhere the epoxy resin powder to the surface of the epoxy resin particles, and then the acetone was removed.
It heated at 0 degreeC and created the pseudo particle. This pseudo particle is
The average particle size was about 4.3 μm, and about 75% by weight was in the range of ± 2 μm centering on the average particle size.

(3) 50% acrylate of cresol novolac type epoxy resin (made by Yuka Shell, trade name: Epicoat 180S)
60 parts by weight, 40 parts by weight of bisphenol A type epoxy resin (produced by Yuka Shell, trade name: Epicoat 1001), 15 parts by weight of diallyl terephthalate, 2-methyl-1- [4-
(Methylthio) phenyl] -2-morpholinopropanone-1 (manufactured by Ciba Geigy, trade name: Irgacure 90
7) 4 parts by weight, imidazole (manufactured by Shikoku Kasei, trade name: 2P
4 MHZ) 4 parts by weight and 50 parts by weight of the pseudo particles prepared in (2) above are mixed, and while adding butyl cellosolve, the viscosity is adjusted to 250 cp with a homodisper stirrer, and then kneaded with three rollers to form a photosensitive resin. A solution of the composition was made.

(4) Apply the solution of the photosensitive resin composition prepared in (3) on the wiring board prepared in (1) using a knife coater, leave it in a horizontal state for 20 minutes, and then dry at 70 ° C. Then, the photosensitive resin insulating layer 3 having a thickness of about 50 μm was formed.

(5) A photomask film having a 100 μmφ black circle printed thereon was brought into close contact with the wiring board subjected to the treatment of (4), and exposed at 500 mj / cm ² by an ultra-high pressure mercury lamp. This was subjected to ultrasonic development treatment with a chlorocene solution to form a 100 μmφ via hole on the wiring board. The wiring board is exposed by an ultra-high pressure mercury lamp at about 3000 mj / cm ² ,
Further, by heat-treating at 100 ° C. for 1 hour and then at 150 ° C. for 10 hours, a resin insulating layer 3 corresponding to a photomask film and having openings having excellent dimensional accuracy was formed.

(6) Chromic acid (Cr ₂ O
₃ ) Immerse in an oxidizing agent consisting of 500 g / l aqueous solution for 15 minutes at 70 ° C. to roughen the surface of the interlayer resin insulation layer as shown in FIG. It was immersed in a neutralizing solution (PN-950 manufactured by Shipley) and washed with water.

The surface of the insulating layer is activated by applying a palladium catalyst (Cataposit 44, manufactured by Play Co.) to the substrate with the resin insulating layer roughened, and immersed in an electroless copper plating solution having the composition shown in Table 1 for 11 hours. Then, electroless copper plating with a plating film thickness of 25 μm was performed.

(7) After repeating the steps (1) to (6) twice, and further performing the step (1), the conductor circuit 5 having four wiring layers, that is, the second layer, A build-up multilayer wiring board in which the conductor circuit 6 of three layers and the conductor circuit 7 of the fourth layer were formed was prepared.

Example 2 (1) Epoxy resin particles (Torepal EP-B, manufactured by Toray Industries, Inc., average particle size 0.5 μm) were placed in a hot-air dryer and heat-treated at 180 ° C. for 3 hours to cause cohesive bonding. The agglomerated epoxy resin particles were dispersed in acetone, crushed with a ball mill for 5 hours, and then classified using an air classifier,
Aggregated particles were created. The aggregated particles have an average particle size of about 3.
5 μm, and about 68% by weight is centered around the average particle size ±
It was present in the range of 2 μm.

(2) 50 parts by weight of 75% acrylate of cresol novolac type epoxy resin (Nippon Kayaku, trade name: EOCN-103S),
Bisphenol A type epoxy resin (made by Dow Chemical,
Product name: DER661) 50 parts by weight, dipentaerythritol hexaacrylate 25 parts by weight, benzyl alkyl ketal (manufactured by Ciba Geigy, product name: Irgacure 651)
5 parts by weight, imidazole (manufactured by Shikoku Kasei, brand name: 2P4MH
Z) 6 parts by weight, and 50 agglomerated particles prepared in (1) above
After mixing the parts by weight, the viscosity was adjusted to 250 cp with a homodisper stirrer while adding butyl cellosolve, and then kneaded with three rollers to prepare a solution of the photosensitive resin composition.

(3) The solution of the photosensitive resin composition prepared in (2) above is placed on a wiring board (substrate 2) having the same first-layer conductor circuit 1 prepared in (1) of Example 1 with a knife coater. Was applied, left standing in a horizontal state for 20 minutes, and then dried at 70 ° C. to form a photosensitive resin insulating layer 3 having a thickness of about 50 μm.

(4) Next, the step (5) of Example 1 was performed to form the interlayer resin insulating layer 3 having openings.

(5) Next, by performing the step (6) of Example 1, the surface of the resin insulating layer 3 was roughened as shown in 4 (b), and electroless copper plating was performed.

(6) Step (1) of Example 1 and the above (1) to
By repeating (5) twice and further carrying out (1) of Example 1, there are four wiring layers, that is, the conductor circuit 5 of the second layer, the conductor circuit 6 of the third layer, and the conductor of the fourth layer. Circuit 7
A build-up multilayer wiring board having the above-mentioned structure was obtained.

Example 3 (1) 100 parts by weight of 50% acrylate of phenol aralkyl type epoxy resin, 15 parts by weight of diallyl terephthalate, 2-methyl-1- [4- (methylthio) phenyl]
-2-Morpholinopropanone-1 (Ciba Geigy, trade name: Irgacure-907) 4 parts by weight, imidazole curing agent (Shikoku Kasei, trade name: 2P4MHZ) 4 parts by weight Epoxy resin powder with large particle size (Toray) Made, Trepearl EP-
B, average particle size 3.9 μm) Epoxy resin powder with 10 parts and small particle size (Toray, Trepal EP-B, average particle size 0.5 μ)
m) Butyl carbitol was added to 25 parts by weight, the viscosity was adjusted to 250 cp with a homodisper disperser, and then kneaded with three rollers to prepare a solution of the photosensitive resin composition.

(2) A solution of the photosensitive resin composition prepared in (2) above is placed on a wiring board (substrate 2) having the same first-layer conductor circuit 1 prepared in (1) of Example 1 with a knife coater. Was applied and left for 20 minutes in a horizontal state, and then dried at 70 ° C. to form a photosensitive resin insulating layer having a thickness of about 50 μm.

(3) Then, the step (5) of Example 1 was performed to form an interlayer insulating layer having openings.

(4) Next, the surface of the resin insulating layer 3 was roughened by performing the step (6) of Example 1, and electroless copper plating was performed.

(5) (1) of Example 1 and the above (1) to (4) are 2
By repeating the procedure (1) of Example 1 repeatedly, a wiring layer having four layers, that is, a second-layer conductor circuit 5, a third-layer conductor circuit 6, and a fourth-layer conductor circuit 7 are formed. A build-up multilayer wiring board was obtained.

Example 4 (1) 60 parts by weight of phenol novolac type epoxy resin (Oilized shell, trade name: E-154), 40 parts by weight of bisphenol A type epoxy resin (Oilized shell, trade name: E-1001), Imidazole curing agent (Shikoku Kasei, trade name: 2P4MH
Z) 4 parts by weight, large particle size epoxy resin powder (Toray, trade name: Trepearl EP-B, average particle size 3.9 μm) 10 parts by weight, and small particle size epoxy resin powder (Toray trade name: Butyl carbitol was added to 25 parts by weight of Trepal EP-B, average particle size 0.5 μm, the viscosity was adjusted to 250 cp with a homodisper disperser, and then the mixture was kneaded with 3 rollers to prepare an adhesive solution. did.

(2) Next, the adhesive solution prepared in (1) above is roll-coated on the wiring board (substrate 8) obtained by photoetching the surface copper foil of the glass epoxy double-sided copper clad laminate by a conventional method. And then dried and cured at 100 ° C. for 1 hour and further at 150 ° C. for 5 hours to form a resin insulating layer 10.

(3) The substrate 8 was irradiated with the CO ₂ laser 14 toward the conductor circuit 9 of the wiring board on which the resin insulating layer 10 was covered, and the holes 15 were formed in the resin insulating layer 10.

(4) Then, immerse in chromic acid for 10 minutes to form the resin insulation layer.
The surface of 10 was roughened as shown in 11, neutralized and washed with water.

(5) Through holes were formed by a conventional method.

(6) A palladium catalyst (manufactured by Play Co., Ltd., Cataposit 44) was applied to the substrate to activate the surface of the resin insulating layer.

(7) Next, a photosensitive dry film (manufactured by San Nopco, trade name: DFR-40C) was laminated on the wiring board, and the conductor pattern was exposed and then developed.

(8) Immerse in an electroless copper plating solution shown in Table 1 for 11 hours to form a multilayer printed wiring board having a conductor circuit 13 which is a 25 μm-thick electroless copper plating film formed in a portion excluding the plating resist 12. Manufactured.

Example 5 Same as Example 4, but in this example, after roughening the surface of the resin insulating layer 10 with chromic acid, a CO ₂ laser 14 was irradiated to form an opening 15 in the resin insulating layer 10. Thus, a multilayer printed wiring board was manufactured.

The adhesion strength between the insulating layer and the electroless plated film of the thus-produced multilayer printed wiring board was measured by the method of JIS-C-6481, and the results are shown in Table 2.

(Effects of the Invention) As described above, according to the multilayer printed wiring board and the method for manufacturing the same of the present invention, a multilayer printed wiring board having excellent adhesion between a conductor circuit made of an electroless plating film and an insulating layer is provided. It is possible to do so, and the effect of contributing to the industry is extremely large.

[Brief description of drawings]

(A) to (d) of FIG. 1 are diagrams showing the manufacturing process of the build-up multilayer wiring of the first embodiment, and (a) to (d) of FIG. 2 are the build-up multilayer of the second embodiment. 3A to 3D are views showing the manufacturing process of the wiring, FIGS. 3A to 3D are views showing the manufacturing process of the build-up multilayer wiring of the third embodiment, and FIGS. 5A to 5F show the manufacturing process of the buildup multilayer wiring of Example 4, and FIGS. 5A to 5F show the manufacturing process of the buildup multilayer wiring of Example 5 respectively. It is a figure. 1 ... First layer conductor circuit, 2 ... Substrate, 3 ... Interlayer insulating layer, 4 (a), 4 (b), 4 (c) ... Enlarged cross-sectional view of roughened portion, 5 ... 2 layer conductor circuit, 6 ... 3rd layer conductor circuit, 7 ... 4th layer conductor circuit, 8 ... Substrate, 9 ... Conductor circuit, 10 ... Interlayer insulating layer, 11 ... Roughened part Enlarged cross-sectional view of 12 ... Plating resist, 13 ... Conductor circuit formed by electroless copper plating, 14 ... CO ₂ laser light

Claims (4)

[Claims] 1. A multilayer printed wiring board in which a plurality of conductor circuits obtained by electroless plating are electrically insulated by a resin insulation layer made of a heat resistant resin, wherein the resin insulation layer is against an oxidant. A mixture of heat-resistant resin particles having an average particle diameter of 2 to 10 μm and heat-resistant resin fine powder having an average particle diameter of 2 μm or less in a heat-resistant resin that is hardly soluble, and an average particle diameter of 2
Pseudo particles formed by adhering at least one of heat-resistant resin fine powder having an average particle size of 2 μm or less or inorganic fine powder having an average particle size of 2 μm or less to the surface of heat-resistant resin particles having an average particle size of 2 μm At least one selected from agglomerated particles obtained by aggregating the following heat-resistant resin fine powders to have an average particle size of 2 to 10 μm; that is, containing heat-resistant particles soluble in an oxidant The resin insulation layer on the surface of which the electroless plating film is formed,
A multilayer printed wiring board, characterized in that a recess for anchor formation of an electroless plating film is provided in a portion of the heat resistant particles which is dissolved and removed by treatment with an oxidizing agent. 2. The multilayer print according to claim 1, wherein the heat resistant particles are mixed in an amount of 5 to 350 parts by weight based on 100 parts by weight of the solid content of the heat resistant resin which is hardly soluble in an oxidizing agent. Wiring board. 3. A method for producing a multilayer printed wiring board having a plurality of conductor circuits made of an electroless plated film electrically insulated by a resin insulating layer made of a heat resistant resin, comprising at least the following (a) to (c): ) Step; that is, (a) heat-resistant resin particles having an average particle diameter of 2 to 10 μm and an average particle diameter of 2 μm or less with respect to a heat-resistant resin that is hardly soluble in an oxidant Mixture with heat-resistant resin fine powder, at least one of heat-resistant resin fine powder having an average particle diameter of 2 μm or less or inorganic fine powder having an average particle diameter of 2 μm or less on the surface of heat-resistant resin particles having an average particle diameter of 2 to 10 μm Or at least one selected from the group consisting of pseudo particles obtained by adhering particles, or agglomerated particles having an average particle size of 2 to 10 μm obtained by aggregating a heat-resistant resin fine powder having an average particle size of 2 μm or less, That is, a step of forming one or more resin insulating layers in which heat-resistant particles soluble in an oxidizing agent are dispersed: (b) Only the heat-resistant particles existing on the surface portion of each resin insulating layer Is dissolved and removed using an oxidizing agent to roughen the surface on the side on which the electroless plating film is formed: (c) By performing electroless plating on the roughened resin insulation layer, A step of forming a conductor circuit: The method for producing a multilayer printed wiring board, comprising: 4. The multilayer print according to claim 3, wherein the heat resistant particles are mixed in an amount of 5 to 350 parts by weight with respect to 100 parts by weight of a solid content of the heat resistant resin which is hardly soluble in the oxidizing agent. Wiring board manufacturing method.