JPH03229780A - Adhesive for electroless plating, excellent in anchoring effect, and manufacture of printed wiring board by using it - Google Patents

Abstract

PURPOSE:To form the title adhesive excellent in heat resistance, electrical characteristics, and adhesiveness and useful for obtaining a printed wiring board by dispersing an acid-soluble, precured, heat-resistant resin powder in a specified heat-resistant matrix resin. CONSTITUTION:The title adhesive is formed by dispersing an acid-soluble, precured, heat-resistant resin powder (e.g. epoxy resin particles) preferably having a mean particle diameter of 10mum or smaller in an uncured heat-resistant matrix resin which becomes hardly soluble or insoluble in acid when cured (e.g. a mixture of a phenolic novolak epoxy resin with a bisphenol A resin).

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is directed to an adhesive having an excellent anchoring effect (adhesion of electroless plated film) and manufacturing a highly accurate printed wiring board using this adhesive. Regarding the method, we proposed an adhesive for manufacturing printed wiring boards that has particularly good heat resistance, electrical insulation, and chemical stability, and in particular, has a sharp anchor shape that provides extremely excellent adhesion to the plating film. ,
The present invention relates to a method for advantageously manufacturing a high-precision printed wiring board using this adhesive.

[Conventional technology]

BACKGROUND ART In recent years, advances in electronics have been remarkable, and as a result, electronic devices need to be further miniaturized or faster. For this reason, printed wiring boards, especially printed wiring boards on which parts such as ICs and LSIs are mounted, are required to have higher density through fine patterns and higher reliability.

Conventionally, a typical technique for forming a conductor circuit (pattern) on a printed wiring board is a method called an etched foil method in which a thin copper layer is laminated on a board and then photo-etched. This method has the feature of being able to form a conductor pattern with excellent adhesion to the board, but on the other hand, it has the major drawback that it is difficult to obtain a highly accurate fine pattern by etching because the copper foil is thick. Moreover, there were also problems such as the manufacturing process was complicated and inefficient.

Therefore, recently, in order to form conductor circuits on wiring boards,
Additive methods are gaining attention, in which an adhesive containing diene-based synthetic rubber is applied to the substrate surface to form an adhesive layer, the surface of this adhesive layer is roughened, and then electroless plating is applied to form a conductor circuit pattern. I have been bathed in

However, since the adhesive used in this known method contains synthetic rubber in its composition, it has drawbacks such as a significant decrease in adhesion strength at high temperatures and blistering of the electroless plating film during soldering. was there. In addition, the heat resistance is low and the electrical properties such as surface resistance are not sufficient, so the range of application is severely limited.

A resin composition J for printed wiring boards, which is used to form conductor patterns by electroless plating, has been proposed as disclosed in JP-A-53-140344. However, this composition The thing is
The thermosetting resin component forming the spherical particles in the composition is not etched (treated with an M-forming agent) and is insoluble in so-called oxidizing agents. The adhesive layer on the substrate obtained by etching and roughening this resin composition has irregularities with a depth of about 20 μm, so it is difficult to obtain a fine pattern of the conductor formed on this adhesive layer. The insulation between patterns tends to be poor, and the heat resistance and electrical properties are also poor, making it undesirable for mounting components.

[Problem to be solved by the invention]

In order to solve these problems, the inventors of the present invention have conducted various researches and found that they first have good heat resistance, electrical insulation, and chemical stability, and in particular have good adhesion between the substrate and the electroless plated film. Excellent, and
He invented an adhesive for electroless plating that is easy to handle during plating, and a method for manufacturing printed wiring boards using such an adhesive, and published Japanese Patent Application Laid-Open Nos. 61-276875 and 1999-1-
No. 275682, JP-A-1301774, JP-A-2-
No. 8281 and JP-A-2-8283.

However, the adhesives of the invention and the methods of manufacturing printed wiring boards using these adhesives, which were proposed prior to the present invention, require the use of heat-resistant resin fine powder that is soluble in oxidizing agents and that has been cured in advance. , an adhesive that is dispersed in an uncured heat-resistant matrix-forming resin that becomes poorly soluble in oxidizing agents when cured, and this adhesive is applied onto a substrate and dried and hardened. A manufacturing method comprising: forming an adhesive layer by dissolving and removing at least a portion of the fine powder scattered on the surface of the adhesive layer, roughening the surface of the adhesive layer, and then subjecting the adhesive layer to electroless plating. , is the basis.

Therefore, in these methods, it is necessary to use an oxidizing agent such as chromic acid in order to dissolve and remove a portion of the heat-resistant fine powder and roughen the surface of the adhesive layer.

However, regarding the use of oxidizing agents such as chromic acid, ■
- Oxidizing agents such as chromic acid are hazardous substances and are not only difficult to dispose of and process, but also difficult to handle and require special equipment and precautions in the working environment. Various problems remained. ■Furthermore, this oxidizing agent tends to slightly dissolve the heat-resistant resin that forms the matrix, so there is a problem that the shape of the anchor that is formed loses its sharpness. There were inconveniences such as the need to use agglomerated particles to complicate the shape of the anchor.

The purpose of the present invention is to solve the above-mentioned problems faced by the prior art, and to provide not only excellent heat resistance and electrical properties, but also excellent adhesion due to the particularly good anchor shape, and easy implementation. The purpose of the present invention is to propose an easy adhesive for electroless plating and a method for easily manufacturing a high-precision printed wiring board using this adhesive.

[Means to solve the problem]

The present invention aims to improve the above-mentioned invention previously proposed by the present inventors, and is designed to be lower in cost, free from common problems such as pollution and work environment, and the shape of the anchor ensures constant adhesion. As a result of intensive research to develop an adhesive that was devised to have an appropriate shape to make it good,
It has been found that all of the above-mentioned problems can be solved by using a heat-resistant resin powder that is soluble in acids.

In other words, the present invention provides an uncured matrix-forming heat-resistant resin that has the property that the heat-resistant resin powder, which is soluble in acids and has been cured in advance, becomes poorly soluble or insoluble in acids when cured. We propose an adhesive consisting of interspersed materials.

Using such an adhesive, first apply this adhesive to a substrate, dry and harden it to form an adhesive layer, then polish the surface of this adhesive layer, and then apply it to a substrate. At least a portion of the heat-resistant resin powder scattered on the surface of the adhesive layer is exposed on the surface of the adhesive layer, and after this state is obtained, a portion of the resin powder is dissolved and removed with acid. By doing this, they roughened the surface of the adhesive layer, and then applied electroless plating to the roughened surface of the adhesive layer to form the required conductor pattern, thereby developing a method for manufacturing desirable printed wiring boards. .

[For production]

The adhesive for electroless plating according to the present invention has the property of becoming poorly soluble or insoluble in acids by curing a heat-resistant resin powder that has been cured in advance and is soluble in acids. It is dispersed in an uncured heat-resistant resin for forming a matrix.

The reason why such adhesives are used for electroless plating of printed wiring boards is that when forming an electroless plating film on the board, it increases the adhesion strength of the plated conductor and, in turn, increases the reliability of the conductor pattern. This is because it can be obtained. That is, heat-resistant resin powder that has been cured in advance is dispersed in a heat-resistant resin liquid for forming a matrix, which is then applied onto a substrate, dried, and cured. An adhesive layer is formed in which heat-resistant resin powder is uniformly dispersed in a heat-resistant resin (for heat-resistant resin). On the other hand, since the heat-resistant resin powder and the heat-resistant resin for forming matrix-nox have extremely different solubility in acid, when the adhesive layer is treated with acid, Of the powders dispersed on the surface of the adhesive layer, only those that are soluble in acid are dissolved and removed.

As a result, sharp anchors (indentations) are formed on the surface of the adhesive layer, and the roughened surface of the adhesive layer becomes sharp.

Now, the heat-resistant resin powder used in the present invention has been previously hardened. If a heat-resistant resin powder that has not been hardened is used, when it is added to a heat-resistant resin solution for matrix formation or a solution in which this resin is dissolved using a solvent, it will dissolve in the solution. Therefore, when an adhesive containing such an uncured resin powder is applied to a substrate and dried and cured, an adhesive layer is obtained in which the heat-resistant resin for matrix-nox formation and the heat-resistant resin powder for dispersion are eutectic. As a result, during the acid treatment described above, the adhesive layer is almost uniformly dissolved, making it impossible to selectively dissolve and remove the surface of the adhesive layer, which is necessary for surface roughening. This prevents the formation of so-called anchors for ensuring plating adhesion.

On the other hand, the heat-resistant resin powder employed in the present invention is
Because it has been hardened in advance, it is poorly soluble or insoluble in the heat-resistant resin liquid or the solvent that dissolves this resin, so it is uniformly dispersed in the matrix heat-resistant resin liquid dissolved as a resin powder. The situation is as follows.

Therefore, if such an adhesive layer is treated with acid, only the soluble resin powder will be dissolved, and a clear, uniform, and sharp anchor can be formed as described above. It is.

The heat-resistant resin powder used in the present invention includes (1) Agglomerated particles having an average particle size of 2 to 10 μm by agglomerating heat-resistant resin powder with an average particle size of 2 μm or less;
Heat-resistant resin powder with an average particle size of 2 to 10 μm and an average particle size of 2 μm
Mixture with heat-resistant resin powder of m or less; ■ Average particle size 2-1
Pseudo-particles formed by adhering either a heat-resistant resin fine powder with a particle size of 2 μm or less or an inorganic fine powder with an average particle size of 2 μm or less, whichever is smaller, on the surface of a 0 μm heat-resistant resin powder; When using such a heat-resistant resin powder, the anchor shape, which becomes sharp when using an acid instead of an oxidizing agent, can be made even more complex. In particular, it is more suitable to use the mixture as a heat-resistant resin powder.

Here, among the heat-resistant resin powders, the pseudo particles, agglomerated particles, and the heat-resistant resin powder in the mixture are used with an average particle size of 2 to 10 μm. This is because if the diameter is larger than 10 μm, the anchors formed by dissolution and removal accompanying the oxidation treatment are small and tend to be non-uniformly distributed. In such a case, the adhesion strength of the plating film deteriorates, reducing the reliability of the product, and furthermore, the surface unevenness of the adhesive layer becomes more severe than necessary, making it difficult to obtain a fine conductor pattern. Inconveniences are likely to occur when mounting parts and the like. On the other hand, the average particle size is 2
This is because if it is smaller than μm, the anchor tends to become unclear. More preferably, the size is 3 to 8 μm.

On the other hand, the reason why it is necessary to set the size of the adhering powder of the pseudo particles, the heat-resistant resin powder constituting the aggregated particles, and the heat-resistant resin powder in the mixture to an average particle size of 2 μm or less is as follows. This is because if it is larger than 2 μm, the anchoring effect will be reduced and the adhesion strength of the plating film will be poor. More preferably, the size is 0.8 μI or less.

Further, the particle size of the pseudo particles and aggregated particles is desirably about twice or more of each heat-resistant resin powder constituting the powder attached to the base particles of the pseudo particles and the aggregated particles.

The mixture of the heat-resistant resin powder with an average particle size of 2 to IO μm and the heat-resistant resin powder with an average particle size of 2 μm or less is suitable for making the shape of the formed anchor extremely complex. It is preferable that the content of the heat-resistant resin powder is 50 to 85% by weight.

This heat-resistant resin powder has excellent heat resistance and electrical insulation properties,
It is a resin that exhibits stable properties against chemicals other than acid groups. As this resin, it is necessary to use a resin that becomes sparingly soluble in the matrix-forming heat-resistant resin liquid or solvent by curing in advance, but becomes soluble in acids. For example, it is at least one selected from epoxy resins, polyester resins, and bismaleimide-triazine resins.

Among them, curing agents or crosslinking agents such as polyphenol curing agents, polyamine curing agents, carboxylic acid hydrazides, diamino maleonitriles, dicyandiamide, imitasol polyamine nylon salts and phosphates, Lewis acids and their amine complexes, etc. Cured or crosslinked epoxy resins have excellent properties and are suitable.

Further, as the inorganic powder, for example, calcium carbonate can be used.

Furthermore, it is necessary that the aggregated particles and pseudo-particles are bonded together with such adhesive strength that they do not dissociate and return to primary particles during mixing.

Pseudo-particles can be made by simply adhering fine powder to the surface of a base particle using a binder, but it is also possible to use a hardened heat-resistant resin powder (base particle) that is soluble in acids. On the other hand, when the mother particles are still in a somewhat soft state, by muffing and adhering the various powders,
It may be hardened after being slightly embedded in the surface of the base particle, or in the case of agglomerated particles, the fine resin powder itself may be heated and fused, or it may be bonded with a binder to form a single particle. They may be bonded with adhesive force such as, and both of these are equally excellent in the anchor forming effect.

As such a heat-resistant resin fine powder, for example, a heat-resistant resin that is thermally hardened and then finely pulverized using a jet mill, a freeze pulverizer, or the like is used.

In addition, primary fine particles obtained by spraying and drying a heat-resistant resin solution before curing treatment, or by adding a water-soluble curing agent to an uncured heat-resistant resin emulsion and stirring it, are dried using a hot air dryer, etc. It can also be produced by drying and heating it, or by adding and mixing various binders and drying it, crushing it using a ball mill, ultrasonic disperser, etc., and then classifying it using a wind classifier, etc. .

The shape of the heat-resistant resin powder obtained in this way is not only spherical but also has various complex shapes, and the shape of the anchor formed is also more complex, resulting in high beer strength and pull strength. It provides adhesion strength such as

Furthermore, the heat-resistant resin powder (pseudo particles) according to the present invention is
6 within a range of 128m based on the central grain size
It is preferable to have a uniformity of 0-t% or more. The reason for limiting the variation is that if the variation is larger than the above range, the reliability of the product will decrease.

Note that the surface of the heat-resistant resin powder (base particles and adhering powder) is coated with matrices and lath-forming heat-resistant resin.
In order to do this, a semi-cured layer or an unreacted functional group may be provided in advance to the extent that it does not dissolve in the matrix.

Next, the heat-resistant resin for forming a matrix that disperses and holds the heat-resistant resin powder and the same kind of powder will be described. This resin must have excellent heat resistance, electrical insulation, chemical stability, and adhesive properties, and must have the property of becoming poorly soluble or insoluble in acids when cured. For example, epoxy resin,
At least one selected from epoxy modified polymide resin, polymide resin, and phenol resin is used. Note that these resins imparted with photosensitivity are suitable as adhesives for interlayer insulating materials for pill doors and printed wiring boards.

As mentioned above, there is a large difference in acid solubility characteristics between the heat-resistant resin powder and the matrix-forming p11 resin after curing. Therefore, when the adhesive layer is treated with acid, the heat-resistant resin powder dispersed on the surface of this layer is dissolved and removed, while the heat-resistant resin powder for forming a matrix that is sparingly soluble or insoluble in the acid The resin remains as a base material without being dissolved, and the portion of the resin powder that has been dissolved and removed forms a depression and forms an anchor. Even if the same type of heat-resistant resin is used, for example, an epoxy resin that is easily soluble in acids is used as the heat-resistant resin powder, and an epoxy resin that is relatively difficult to dissolve in acids is used as the matrix heat-resistant resin. A similar anchoring effect can be obtained by using

Note that as the heat-resistant resin liquid for dispersing the fine powder, a heat-resistant resin liquid that does not contain a solvent can be used as it is, but a heat-resistant resin liquid in which a heat-resistant resin is dissolved in a solvent has a low viscosity. Therefore, it is easy to disperse the powder uniformly and it is easy to apply it to the substrate, so it can be used advantageously.

The solvent used to dissolve the above heat-resistant resin is as follows:
Common solvents such as methyl ethyl ketone, methyl cellosolve, ethyl cellosolve, butyl luhitol, butyl cellulose, tetralin dimethylformamide, n-methylpyrrolidone, etc. can be used.

Note that a filler made of fine inorganic W powder such as silica, alumina, titanium oxide, and zirconia may be appropriately blended into the heat-resistant resin liquid serving as the matrix.

The blending amount of the heat-resistant resin powder in the matrix-forming heat-resistant resin is preferably in the range of 2 to 350 parts by weight based on 100 parts by weight of the solid content of the matrix-forming heat-resistant resin. The reason for this is that if the blending amount of the heat-resistant resin fine powder is less than 2 parts by weight, the density of the anchor formed by dissolving and removing it will be low, and sufficient adhesion strength between the substrate and the electroless plating film will not be obtained. On the other hand, if the amount exceeds 350 parts by weight, most of the surface of the adhesive layer will be dissolved, and the formation of anchors will be substantially inhibited.

In particular, the blending amount of the heat-resistant resin powder in the matrix-forming heat-resistant resin is preferably in the range of 5 to 200 parts by weight based on 100 parts by weight of the solid content of the matrix heat-resistant resin. This is because when the amount is within this range, the adhesion strength between the substrate and the electroless plated film can be increased.

Next, a method of manufacturing a printed wiring board using the above adhesive will be explained.

(al) First, an adhesive in which the heat-resistant resin powder is dispersed in a heat-resistant resin liquid as a matrix is applied onto the substrate, and then the adhesive layer is formed by drying and curing. Method of this application For example, various methods such as a roller coating method, a dip coating method, a spray coating method, a spinner coating method, a curtain coating method, and a screen printing method are used.

In this process, the thickness of the adhesive layer obtained on the substrate by coating, drying and curing the adhesive is usually 2 to 4 mm.
It is about 0 μm. However, when this adhesive layer is used also as an interlayer insulating film for a metal substrate or a multilayer wiring board, it is also effective to apply it thicker than that.

As the substrate used in the present invention, for example, a plastic substrate, a ceramic substrate, a metal substrate, a film substrate, etc. can be used. Specifically, they include glass epoxy substrates, glass borimite substrates, alumina substrates, low-temperature fired ceramic substrates, aluminum nitride substrates, aluminum substrates, iron substrates, polyimide film substrates, and the like.

It is desirable that the surfaces of these substrates be roughened in advance. This increases the adhesion strength between the substrate and the adhesive layer. It is also desirable that these substrates be sufficiently dried before applying the adhesive. The reason for this is that if dry moisture is insufficient, residual moisture will inhibit the curing of the resin.

In the present invention, using these substrates, a single-sided wiring board 1 a double-sided through-hole wiring board 2, a multilayer printed wiring board such as a Cu/polyimide multilayer printed wiring board, etc. can be manufactured. In addition, by forming the adhesive itself into a plate shape or film shape, or by impregnating a glass spray cloth with the adhesive solution and making it into a prepreg, it has adhesive properties that allow electroless plating. It can also be used as a substrate.

Note that a catalyst (nucleus) for roughening electroless plating may be mixed into the adhesive. When such an adhesive is used, the step of applying a catalyst (nucleus) can be omitted.

(bl) Next, by polishing the surface of the adhesive layer formed as described above, the heat-resistant resin powder dispersed in the surface portion is exposed on the surface of the adhesive layer.

In this step, since the heat-resistant resin for matrix formation is poorly soluble or insoluble in acids, if the heat-resistant resin powder is covered with this resin, the heat-resistant resin powder is dissolved and removed with acid. This is because it is difficult to do so. In other words, by exposing the heat-resistant resin powder in advance in this process, it can be easily and efficiently dissolved and removed, and since it is dissolved using acid, the heat-resistant resin for forming the matrix is not dissolved, so the anchor The shape becomes thick.

As a method for polishing the adhesive layer, known methods such as borishing using various fine powder abrasives and liquid honing are used.

(c) Next, at least a portion of the heat-resistant resin powder exposed on the surface is dissolved and removed using an acid.

In the acid treatment, at least one selected from inorganic acids such as hydrochloric acid, sulfuric acid, phosphoric acid, and nitric acid, and organic acids such as acetic acid and formic acid is used, and inorganic acids are particularly effective.

The concentration of the acid is desirably 1% or more because if it is less than 1%, it will take time to process. Further, the temperature of the acid is desirably from room temperature to 70°C or lower, since if the temperature exceeds 70°C, some of the Matri-Nox resin will begin to dissolve.

The method for dissolving and removing the resin particles using this acid is carried out by using the acid solution and immersing the substrate having the adhesive layer in the solution, or by spraying the solution onto the substrate. This process may contain harmful chemicals such as chromic acid.
There is no need to use J'jlt, so there is no time to dispose of the liquid treatment waste, and the surface of the substrate, the so-called adhesive layer, can be roughened without using chromic acid, which is difficult to process. It can be said that this method is more effective than conventional techniques.

(dl) Next, electroless plating is applied to the substrate on which the surface of the adhesive layer has been roughened. Examples of this electroless plating include electrolytic copper plating and electroless nickel plating.

There are electroless soot plating, electroless gold plating, electroless silver plating, etc. Particularly preferred is at least one of electroless copper plating, electroless nickel plating, and electroless gold plating. In addition, in addition to the above electroless plating, a different type of electroless plating or electroplating may be performed,
It may also be coated with solder.

Note that the printed wiring board obtained by carrying out the method of the present invention can also have conductor circuits formed thereon by other known methods, such as a method of applying electroless plating to the board and then etching the circuit, or a method of applying electroless plating to the board and then etching the circuit. A method of directly forming a circuit can be applied.

When forming a conductor circuit by a fully additive method using the adhesive for electroless plating of the present invention, a plating resist is formed, but the thickness of this plating resist must be made thicker than the thickness of the electroless plated conductor layer. is desirable.

The reason for this is explained as follows. Various electronic components are mounted on the surface of a printed wiring board, and the mounting portions of the printed wiring board are coated with solder, and during mounting, the solder is melted by thermocompression bonding and terminals are connected. At this time, in conventional printed wiring boards, there is often a phenomenon where the solder on the surface of adjacent conductor layers melts and flows, forming bridges and shorting between wires, which causes a decrease in yield. There is. However, by making the plating resist thicker than the electroless plated conductor layer,
Such solder bridging can be prevented and the yield can be improved.

Moreover, the printed wiring board obtained by using the adhesive for electroless plating of the present invention may be multilayered, and a build-up multilayer printed wiring board is particularly suitable.

HILTO ASSOBS multilayer printed wiring boards are manufactured using the following process: forming an adhesive layer for electroless plating on the conductor layer, and drilling holes for via holes into the adhesive layer before or after roughening it with acid. It can be manufactured by repeating the steps of forming a conductor layer, applying a catalyst (nucleus), performing electroless plating, and forming a conductor layer.

It is desirable that the heat-resistant resin for forming the matrix of the adhesive for electroless plating used in manufacturing a build-up multilayer printed wiring board has photosensitivity.

This is because when a photosensitive resin is used for the matrix, holes for via holes can be formed with high accuracy by performing exposure and development processing. The build-up multilayer printed wiring board also includes a form in which only mounting pads for mounting electronic components are formed on the surface layer instead of conductive circuits, and the pads are connected to circuits on the inner layer through via holes. It will be done.

Since such a multilayer VI slope has only mounting pads formed on the surface layer, the density of mounting pads is lower than that of a conventional printed wiring board where mounting pads and conductor circuits coexist. This makes it possible to implement high-density mounting of electronic components.

Examples are shown below.

Example 1 (1) Acid-soluble epoxy resin particles (average particle size 3.9μ
200 g of m) was dispersed in 51 acetone to create an epoxy resin particle suspension, and in this suspension,
The following epoxy resin particle-suspended FA solution: ``An acid-soluble epoxy resin fine powder (average particle size 0.5 μm) is added to an acetone solution in which 30 g of epoxy resin is dissolved in acetone IA. A suspension in which 300g of
After adhering the epoxy resin fine powder to the surface of the epoxy resin particles by dropping it dropwise while stirring using a Henschel mixer, the acetone is removed, and then,
Pseudo particles were created by heating to 150°C. The pseudo-particles had an average particle size of 4.3 μm, and about 75% by weight existed in a range of 2 μm around the average particle size.

(2) Adding butyl calpitol to a composition consisting of 50 parts by weight of the pseudo particles prepared in (1) above, 60 parts by weight of phenol novolac type epoxy resin, 40 parts by weight of bisphenol A type epoxy resin, and 4 parts by weight of imidazole curing agent,
An adhesive solution was prepared by adjusting the viscosity to 120 cp using a homodisper disperser.

(3) Adding butyl calpitol to a composition consisting of 50 parts by weight of the pseudo particles prepared in (1) above, 60 parts by weight of phenol novolak type epoxy resin, 40 parts by weight of bisphenol A type epoxy resin, and 4 parts by weight of imidazole curing agent,
The viscosity was adjusted to 120 cp using a homodisper disperser to obtain an adhesive solution.

(4) After applying the adhesive solution obtained in (3) above to the glass polyimide substrate 1, the adhesive solution was heated at 100°C for 1 hour.
The adhesive layer 2 with a thickness of 20 μm was formed by drying and curing at 50° C. for 5 hours.

(5) The surface of the adhesive layer 2 was polished using a rotary brush polisher using #1000 fine alumina powder.

(6) The substrate obtained in (5) above was immersed in a 50% sulfuric acid aqueous solution for 20 minutes at room temperature to roughen the surface of the adhesive layer, and then washed with water.

(7) A palladium catalyst was applied to the substrate l on which the roughened surface 4a of the adhesive layer 2 obtained in the above (6) was formed, to activate the roughened surface of the adhesive layer 3.

(8) A photosensitive dry film was laminated onto the substrate 1, and an image was printed by exposing it to ultraviolet light through a mask film on which a desired conductor circuit pattern had been drawn. Then,
It was developed with chlorocene to form a resist 5 for electroless plating.

(9) Immerse the substrate l that has undergone the treatment in step (8) in an electroless copper plating solution for additive method having the composition shown in Table 1,
Electroless plating was applied to a plating film having a thickness of 20 μm to form a conductor layer (pattern) 6, thereby producing a printed wiring board as shown in FIG. 1(e).

Example 2 (1) Epoxy resin particles soluble in Ia (average particle size 0.5
μm) was placed in a hot air dryer and heat-treated at 180'C for 3 hours to cause cohesive bonding. The aggregated and bonded epoxy resin particles were dispersed in acetone, crushed in a ball mill for 5 hours, and then classified using an air classifier to form aggregated particles. These aggregated particles have an average particle size of approximately 3.5 μm.
About 68% by weight is ±2μm around the average particle size.
existed within the range of

(2) Add butyl calpitol to a mixture of 50 parts by weight of the pseudo particles prepared in (1) above, 60 parts by weight of phenol novolac type epoxy resin, 40 parts by weight of bisphenol A type resin, and 4 parts by weight of imidazole curing agent, and bond. It was made into a drug solution.

(3) After wet-polishing the surface of the glass epoxy substrate 1 to make it rough, heat and dry it at 80°C for 3 hours to remove moisture that inhibits curing, and then apply the adhesive solution prepared in (2) above. The adhesive layer 2 was coated with a roll coater and dried and cured at 100° C. for 1 hour and then at 150° C. for 5 hours to form an adhesive layer 2 with a thickness of 20 μm.

(1) The surface of the adhesive layer 2 was polished using a rotary brush polisher using #1000 fine alumina powder.

(5) The substrate 1 obtained in the above (4) was immersed in a 6N hydrochloric acid aqueous solution at room temperature for 20 minutes to roughen the surface of the adhesive layer 2 to form a roughened surface 3, and then washed with water.

(6) A palladium catalyst was applied to the substrate l having the roughened surface 4b of the adhesive layer 2 obtained in (5) above to activate the surface of the adhesive layer.

(7) A photosensitive dry film was laminated onto the substrate 1, and an image was printed by exposing it to ultraviolet light through a mask film on which a desired conductor circuit pattern had been drawn. Then,
It was developed with chlorocene to form a resist 5 for electroless plating with a thickness of 40 μm.

(8) Immerse the substrate l that has been treated in (7) above in an electroless copper plating solution for additive method having the composition shown in Table 1,
Next, using the electrolytic plating solution shown in Table 2, electrolytic plating was performed to a thickness of 30 μm to form a conductor layer (pattern).
6 was formed.

(9) Next, solder plating with a thickness of 5 μm was further performed on the conductor layer 6 to obtain a printed wiring board as shown in FIG. 2 (fe).

Example 3 (1) A glass epoxy substrate 1 with inner conductor layers 6 formed on both sides according to a conventional method was prepared.

(2) 60 parts by weight of phenol novolac type epoxy resin, 40 parts by weight of bisphenol A type epoxy resin, 4 parts by weight of imidazole curing agent, acid-soluble epoxy resin powder as coarse particles and fine powder for anchor formation, average 10 parts by weight of particle size 3.9 μm and average particle size 0.5 μm
An adhesive solution was prepared by adding butylcarpitol to 25 parts by weight of the same.

(3) By the same method as (4) and (5) of Example 1,
After forming the adhesive layer 2, the adhesive layer was roughened with a phosphoric acid aqueous solution to form a roughened surface 4c.

(4) A through hole 16a for forming the through hole 16 was formed using a drill.

(5) A palladium catalyst was applied to the substrate 1 to activate the roughened surface 3 of the adhesive layer.

(6) Using the methods (8) and (9) of Example 1, the thickness was 30 mm.
A multilayer printed wiring board as shown in FIG. 3 was manufactured by forming a plating resist having a thickness of .mu.m and performing electroless plating to a thickness of 25 .mu.m to form a second plated conductor layer 9.

Example 4 (1) Adhesive solution obtained in the same manner as in Example 1, mixed with 1% by weight of thixotropic agent and 0.5% by weight of leveling agent.
The impregnating liquid was prepared by adding each of them so as to contain the same amount by weight.

(2) A coupling agent (PhSi (
A glass woven fabric 8 coated with OEt) 3 was immersed. This was then dried at 150°C for 70 minutes to produce a prepreg.

(3) Lay two sheets of the prepreg on both sides of the double-sided wiring board of the substrate l on which the inner conductor layer 6 has already been formed, and
Adhesive layer 2 was formed by applying pressure at 50° C. and 40 kg/cm 2 for 200 minutes.

(4) Roughen the adhesive layer 2 with a phosphoric acid aqueous solution and roughen the roughened surface 4.
I got a.

(5) A through hole for forming the through hole 16 was formed using a drill.

(6) A palladium catalyst was applied onto the substrate l to activate the roughened surface 3 of the adhesive layer.

(7) Using the methods (8) and (9) of Example 1, the thickness was 30 mm.
After forming a plating resist 5 having a thickness of 25 μm, a second plated conductor layer 9 was formed by electroless plating to a thickness of 25 μm, thereby producing a multilayer printed wiring board as shown in FIG. 4.

Example 5 (1) An adhesion side solution was prepared in the same manner as in Example 3.

(2) After the adhesive was applied to one side of the polyethylene film 14, it was dried at 100° C. for 1 hour to be in a semi-cured state, and the adhesive film 14 was prepared.

(3) After roughening the surface of the glass epoxy substrate I by wet polishing, the adhesive film 14 obtained in the above (2) was dried by heating at 80° C. for 3 hours to remove moisture that inhibits curing. were laminated and pressed at 150° C. and 40 kg 7 cm 2 for 200 minutes to form adhesive layer 2.

(4) After peeling off the polyester film 14, the surface of the adhesive layer 1 was polished using a rotary blank polisher using #1000 Flumina powder.

(5) The substrate obtained in (4) above was immersed in a 6N hydrochloric acid aqueous solution for 20 minutes at room temperature to roughen the surface of the adhesive (3), and then washed with water.

(6) A palladium catalyst was applied to the substrate 1 having the roughened surface 4C of the adhesive layer 2 obtained in (5) above to activate the roughened surface 3 of the adhesive layer.

(7) A photosensitive dry film was laminated on the base +Iil, a desired conductor circuit pattern was drawn, and the film was exposed to ultraviolet light through a mask film to print the image. Then, it was developed with chlorocene to form a resist 5 for electroless plating with a thickness of 40 μm.

(8) Electroless plating was applied to the plated film to a thickness of 30 μm by immersing it in an electroless copper plating solution for additive method having the composition shown in Table 1 to form a conductor pattern.

(9) Solder plating was performed to a thickness of 5 μm to obtain a printed wiring board in which a solder plating layer 7 was further formed on the conductor layer 6 as shown in FIG. 5 (hl).

Example 6 (1) A wiring board was formed by etching the glass epoxy hollow soundboard 1.

(2) Pseudo-particles were created in the same manner as in Example ①. These pseudo-particles had an average particle size of about 4.3 μm, and about 75% by weight existed in a range of 128 m around the average particle size.

(3) 60 parts by weight of 50% acrylate of Talesol novolak epoxy resin, 60 parts by weight of 50% acrylate of bisphenol A epoxy resin, 40 parts by weight of bisphenol A epoxy resin, and 15 parts by weight of diallyl terephthalate. , 2-methyl-1-C4-(methylthio)phenyl] After mixing 4 parts by weight of 2-morpholinopropanone-1, 4 parts by weight of imidazole, and 50 parts by weight of the pseudo particles prepared in (2) above, While adding butyl cellosolve, adjust the viscosity to 250 cρ using a homodisper stirrer.
and then knead with three rollers to form a photosensitive resin.
A solution of the composition was prepared.

(4) An alkaline sodium chlorite solution was prepared by dissolving 60 g of sodium chlorite, 18 g of sodium hydroxide, 5 g of sodium phosphate, and 5 g of sodium chloride in water.

(5) 30% by weight formalin water? Yong, night 3f) d, 38
An alkaline reducing agent aqueous solution was prepared by dissolving g of KOH in water IN.

(6) The wiring board prepared in (1) above was immersed in the alkaline sodium chlorite solution obtained in (4) above for 2 to 3 minutes. Then, it was immersed in the aqueous alkaline reducing agent solution prepared in (5) above at 70''C for 15 minutes to roughen it.

(7) On the wiring board prepared in (6) above, apply the solution of the photosensitive resin composition prepared in (3) above using a knife coater, leave it in a horizontal state for 20 minutes, and then apply the solution at 70°C. This was dried to form a photosensitive resin insulating layer with a thickness of about 50 μm.

(8) 100 μmφ on the wiring board treated in (7) above.
Closely attach the black circle or printed photomask film,
Exposure was performed using an ultra-high pressure mercury lamp at 500 mJ/cm2. By subjecting this to ultrasonic development using a chlorocene solution, an opening 17a that would become a 1100 A1 diameter hole 17 on the wiring board was formed.

This wiring board was heated to approximately 3000 mJ/
cm2, then 1 hour at 100°C, then 15
A resin insulating layer (adhesive layer) 2 as shown in FIG. 6(b) has openings 17a with excellent dimensional accuracy corresponding to a photomask film by heat treatment at 0° C. for 10 hours.
1 was formed.

(9) After polishing the resin insulating layer 21 with #1000 alumina powder, the resin insulating layer was heated in a nitric acid solution at 70°C.
The surface of the glabellar resin insulating layer was roughened by immersion in water for 15 minutes, and then immersed in a neutralizing solution and washed with water.

After applying a palladium catalyst to the substrate l on which the resin insulating layer 2' has been roughened 4a to activate the surface of the insulating layer 2' and forming a plating resist according to a conventional method, a plating resist having the composition shown in Table 1 is applied. The second plated conductor layer 9 was immersed in an electrolytic copper plating solution for 11 hours to provide electroless copper plating with a thickness of 25 μm.
was formed.

By repeating steps (4) to (9) twice, the third
The plated conductor layer 10 and the fourth plated conductor layer 11 are sequentially formed to form a build-up multilayer arrangement V! as shown in FIG. 6 Fdl.
The board was manufactured.

Example 7 This example is basically the same as Example 6, but with a second
Instead of the plated conductor layer 9 formed in the layer, a pad 12 (which is electrically connected to the underlying conductor circuit through a via hole) is formed, and a solder coat 13 is applied to this.
Only pads for mounting semiconductor components are formed.
A printed wiring board as shown in FIG. 7 was manufactured.

Example 8 This example is basically the same as Example 1, but in this example, a palladium catalyst was added to the adhesive for electroless plating, and the step of applying the palladium catalyst was omitted.

Table 1 Conditions for electroless copper plating Table 2 Conditions for electrolytic plating Comparative example 1 This comparative example is basically the same as Example I, except that the average grain size is 3.9 μm and the average grain size is 0.5 μm. In place of the acid-soluble epoxy resin particles, an oxidizing agent with an average particle size of 3.9 μm and an average particle size of 0.5 μm can be used. Pseudo-particles were prepared using hard-bodied epoxy resin particles, and roughening treatment was performed using chromic acid (oxidizing agent) instead of 50% sulfuric acid.
A printed wiring board as shown in the figure was manufactured.

Comparative Example 2 This comparative example is basically the same as Example 2 in about 6 points, but
Instead of acid-soluble epoxy resin particles with an average particle size of 0.5 μm, oxidizing agent-soluble epoxy resin particles with an average particle size of 0.5 μm are used to produce agglomerated particles with an average particle size of about 3.5 μm. was prepared and subjected to roughening treatment using chromic acid (oxidizing agent) instead of 6N hydrochloric acid to produce a printed wiring board as shown in FIG. 9.

Comparative Example 3 This comparative example is basically the same as Example 3, but instead of acid-soluble epoxy resin particles with an average particle size of 3.9 μm and an average particle size of 0.5 μm, An oxidizing agent-soluble epoxy resin with an average particle size of 3.9 μm and 0.5 μm was used, and roughening treatment was performed using chromic acid (oxidizing agent) instead of phosphoric acid to form a material as shown in Figure 1O. Manufactured printed wiring boards.

Regarding the printed wiring boards obtained in Examples 1 to 8 and Comparative Examples 1 to 3 as explained above, the strength of the interposition between the substrate and the same plating film was measured by the method of J [S-(, -6481). .

In addition, changes in the surface resistance of the adhesive layer were measured by immersing the printed wiring board in boiling water at 100°C.

These results are shown in Table 3.

[Effect of the invention] As explained above, according to the present invention, the heat resistance, electrical properties, and adhesion between the substrate and the electroless plating pattern are extremely excellent, and in particular, when the surface is roughened, the matrix can be removed evenly. Since the anchor does not dissolve in water, the anchor shape becomes sharp, and an adhesive for electroless plating with extremely excellent plating adhesion can be provided.

Moreover, by using such an adhesive, there is no need for complicated conditions to sufficiently roughen the surface when manufacturing printed wiring boards, and no harmful substances such as chromic acid are used. The trouble of disposing of and processing them can be saved, and furthermore, there is no need for special equipment or precautions regarding the working environment.

In this sense, the present invention is applicable to a wide range of fields such as high-density and high-precision printed wiring boards, hybrid IC wiring boards, and multilayer wiring boards mounting LSI, and is extremely useful industrially.

[Brief explanation of drawings]

Figures 1 (al to fe) are diagrams showing the manufacturing process of Example 1, Figure 2 (al to (el) are diagrams showing the manufacturing process of Example 2, and Figure 3 (al to (e) are diagrams showing the manufacturing process of Example 2. ) is a diagram showing the manufacturing process of Example 3, FIG. 4 is a cross-sectional view of the printed wiring board obtained in Example 4, and FIG. 5 (al to h) is a diagram showing the manufacturing process of Example 5. 6(al to d) are diagrams showing the manufacturing process of Example 6, FIG. 7 is a cross-sectional view of the printed wiring board obtained in Example 7, and FIG. 8 is a diagram showing the manufacturing process of Example 6. 9 is a sectional view of a printed wiring board based on Comparative Example 1, FIG. 9 is a sectional view of a printed wiring board based on Comparative Example 2, and FIG. 10 is a sectional view of a printed wiring board based on Comparative Example 3. ... Substrate, 2... Adhesive layer, 2'... Insulating layer, 3... Roughened surface, 4a... Adhesive layer containing pseudo particles, 4b... Adhesive layer containing aggregated particles, 4c...Adhesive layer containing two types of particles with different particle sizes, 5
... Plating resist, 6... Conductor layer, 7... Solder plating layer, 8... Glass woven fabric, 9... Second plated conductor layer, 1o... Third plated conductor layer, 11 ... Fourth plated conductor layer, 12... Pad 13... Solder coat, 14... Polyethylene film 15a... Adhesive layer 1 containing pseudo particles roughened with oxidizing agent
5b...Adhesive layer 15 containing aggregated particles roughened with an oxidizing agent
c...Adhesive layer containing two types of particles with different particle sizes roughened with an oxidizing agent

Claims (12)

[Claims] 1. Pre-cured heat-resistant resin powder that is soluble in acids is dispersed in an uncured matrix-forming heat-resistant resin that has the property of becoming poorly soluble or insoluble in acids when cured. Adhesive for electroless plating consisting of. 2. The adhesive according to claim 1, wherein the heat-resistant resin powder has an average particle size of 10 μm or less. 3. The heat-resistant resin powder includes: agglomerated particles having an average particle size of 2 to 10 μm by agglomerating heat-resistant resin powder with an average particle size of 2 μm or less, and heat-resistant resin powder with an average particle size of 2 to 10 μm and an average particle size of 2 μm.
Mixture with heat-resistant resin powder of not more than m, average particle size 2-10
Pseudo-particles formed by adhering at least one of heat-resistant resin powder with an average particle size of 2 μm or less or inorganic powder with an average particle size of 2 μm or less on the surface of heat-resistant resin powder with a diameter of 2 μm or less; The adhesive according to claim 1 or 2, which is one type of adhesive. 4. The adhesive according to any one of claims 1 to 3, wherein the heat-resistant resin powder is an epoxy resin. 5. The matrix-forming heat-resistant resin in which the heat-resistant resin powder is scattered is at least one resin selected from epoxy resins, epoxy-modified polyimide resins, polyimide resins, and phenol resins.
4. The adhesive according to any one of 4. 6. When manufacturing a printed wiring board on which a conductor layer is provided via an electroless plating adhesive, at least the following (
Steps a) to (d): (a) A heat-resistant resin powder that is soluble in acids and has been cured in advance is cured to give the substrate the property of being poorly soluble or insoluble in acids. Applying an adhesive dispersed in an uncured heat-resistant resin resin liquid,
The process of forming an adhesive layer by drying and curing this. (b) A step of exposing a portion of the heat-resistant resin powder scattered on the surface of the adhesive layer to the surface of the adhesive layer by polishing the surface of the cured adhesive layer. (c) Roughening the surface of the adhesive layer by dissolving and removing at least a portion of the heat-resistant resin powder exposed on the surface of the adhesive layer with acid. (d) A step of applying electroless plating to the roughened surface. A method for manufacturing a printed wiring board using an adhesive, which comprises: 7. 7. The manufacturing method according to claim 6, wherein the heat-resistant resin powder has an average particle size of 10 μm or less. 8. The heat-resistant resin powder includes: agglomerated particles having an average particle size of 2 to 10 μm by agglomerating heat-resistant resin powder with an average particle size of 2 μm or less, and heat-resistant resin powder with an average particle size of 2 to 10 μm and an average particle size of 2 μm
Mixture with heat-resistant resin powder of not more than m, average particle size 2-10
Pseudo-particles formed by adhering at least one of heat-resistant resin powder with an average particle size of 2 μm or less or inorganic powder with an average particle size of 2 μm or less on the surface of heat-resistant resin powder with a diameter of 2 μm or less; The manufacturing method according to claim 6 or 7, which is one type. 9. The manufacturing method according to any one of claims 6 to 8, wherein the heat-resistant resin powder is an epoxy resin. 10. The matrix-forming heat-resistant resin liquid in which the heat-resistant resin powder is dispersed is at least one resin liquid selected from epoxy resins, epoxy-modified polymide resins, polymide resins, and phenol resins. The manufacturing method according to any one of. 11. Any one of claims 6 to 10, wherein the acid used in step (c) is at least one selected from sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, acetic acid, and formic acid.
The manufacturing method described in. 12. 12. The manufacturing method according to claim 6, wherein the electroless plating is at least one of electroless copper plating, electroless nickel plating, and electroless gold plating.