JP2915644B2 - Manufacturing method of printed wiring board - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a printed wiring board, and more particularly to a method for manufacturing a printed wiring board by an additive method which is advantageous for forming a highly reliable conductor circuit.

[0002]

2. Description of the Related Art Conventionally, in the production of printed wiring boards, an additive method of forming a conductive circuit by chemical plating is well known. For example, a full additive method is characterized by passing through the following steps. It is.
(a) a step of applying a catalyst for electroless plating, such as a colloidal palladium compound (aqueous solution containing Pd and Sn ions), to the surface of the roughened adhesive layer on the substrate, (b) if necessary, Step (c) of removing part of the Sn colloid with acid to activate the catalyst (c) After printing or applying a plating resist film or resin solution, form a plating resist based on methods such as exposure, development, and heat treatment (D) a step of fixing the catalyst by heat treatment, (e) a step of performing catalyst activation treatment again with acid, and (f) a step of forming a conductor circuit by electroless plating. To manufacture printed wiring boards.

As one of such prior arts, there is a manufacturing method described in, for example, JP-A-58-128788. This technology, after forming the photoresist,
By subjecting the catalyst-added substrate to heat treatment,
A method to prevent the deposition of Cu and improve the reliability of printed circuit boards is proposed.

[0004]

In this prior art, the reliability is improved by preventing the plating conductor (Cu) from depositing on the photoresist surface. Due to lack of consideration for the factors, sufficient effects were not obtained.

[0005] For example, this conventional manufacturing technique uses a catalyst (Pd
Since the heat treatment for immobilizing the catalyst, which is performed after the application of / Sn), is performed in the air, the catalyst nucleus (Pd) becomes an oxide at this time. Even if it does, it will not be converted to metal Pd, so that palladium oxide (PdO) will remain on the adhesive layer as it is, and this will significantly deteriorate the adhesion of the plated conductor and reduce the reliability of the printed circuit board. There is a problem that the property is reduced.

An object of the present invention is to overcome the problems of the prior art; that is, to develop a technique capable of overcoming a decrease in reliability due to poor adhesion of a plated conductor.

[0007]

As described above, palladium oxide (PdO) produced by a heat treatment in the atmosphere is used.
However, for the phenomenon that inhibits the precipitation of Cu during electroless plating and lowers the peel strength, thereby deteriorating the adhesion of the plated conductor, the present inventors performed a heat treatment for fixing the catalyst, Focusing on performing in a non-oxidizing atmosphere, the present invention has the following structure.

[0008] The method for manufacturing a printed wiring board of the present invention based on the above-described concept has at least one surface thereof.
Metal foil and / or heat-resistant resin-based adhesive or metal
On a substrate on which an adhesive layer made of a rubber-based adhesive is formed
The catalyst nucleus on the adhesive layer, and then electroless
In the method of manufacturing printed wiring boards by plating
In order to fix the catalyst core under a non-oxidizing atmosphere,
The substrate after the application of the catalyst nucleus is heat-treated at a temperature of 50 to 300 ° C.
It is an essence that that. That is, the present invention provides a method in which, after a catalyst is applied on a substrate, for example, a roughened adhesive layer, the temperature of 50 to 300 ° C. is used for fixing a catalyst core in a non-oxidizing atmosphere .
Heat treatment at a temperature , and then, if necessary, forming a resist film on the roughened adhesive layer having the immobilized catalyst nucleus, and then performing exposure development or thermal curing or even printing a liquid resist. This is a method of manufacturing a printed wiring board by forming a plating resist by curing, and then performing electroless plating on the pattern of the plating resist to form a conductor pattern.

In the present invention, modified chlorocene (registered trademark) can be used for the development treatment after exposure in the step of forming a plating resist.

Further, according to the present invention, after the plating resist forming step and before the electroless plating treatment, a hot water washing treatment at 50 to 100 ° C. can be performed.

Further, according to the present invention, in the electroless plating treatment step, a catalyst nucleus activation treatment can be performed before performing the electroless plating.

[0012]

[Action] According to the study of the present inventors, the decrease in the adhesion of the deposited conductor (Cu) observed during electroless plating is due to the fact that the heat treatment for fixing the catalyst was performed in the air. It turned out to be the main cause. It is because of this heat treatment
Since the Pd contained like PdCl ₂ -SnCl ₂ -HCl (colloidal type) solution changes to PdO, when the activation treatment with hydrochloric acid and Sn, the following reaction; , And therefore is not reduced to Pd ⁰ . As a result, catalyst nuclei are insufficient, and plating metal (Cu)
Is less likely to precipitate. According to the measurement results performed by the inventors, the peel strength of the plated conductor was only 0.8 kg / cm on average in the case of the heat treatment for fixing the catalyst performed in the air.

In the present invention, therefore, the heat treatment after the catalyst application performed in the above-mentioned first step (the step of applying the catalyst core and immobilizing the same) is performed in a non-oxidizing atmosphere, that is, in an inert gas atmosphere or a low oxygen concentration. I decided to do it in an atmosphere.
When the heat treatment is performed in such an atmosphere, the generation of PdO as seen in the prior art can be prevented, so that the lack of the catalyst nucleus (Pd) is eliminated, and the plating metal (Cu) is sufficiently deposited. It is.

As an example of the inert gas atmosphere in the heat treatment, a nitrogen gas is preferable, and when the heat treatment is performed in a low oxygen concentration atmosphere, the oxygen concentration is controlled to a level of 1 ppm to 10%. The temperature of the heat treatment for fixing the catalyst is preferably in the range of 50 to 300 ° C. If the temperature is lower than 50 ° C., it cannot be fixed, and if it exceeds 300 ° C., the adhesive is undesirably denatured.

Next, in the present invention, as a measure for improving the peel strength, in addition to the above-mentioned contrivance of the heating atmosphere, selection of an adhesive, specification of a developing solution after exposure, and washing with hot water after a thermosetting treatment of the plating resist are performed. Each method of doing is decided. Hereinafter, the specific contents will be described together with the description of the manufacturing process.

According to the present invention, a printed wiring board is manufactured by applying electroless plating after providing a catalyst core.
This technique is effective when applied to a so-called additive process. This additive process is classified into a partly additive method and a full additive method. The partly additive method means that a substrate provided with a conductor layer, a catalyst nucleus is provided on a substrate formed with holes for through holes and via holes as necessary, and a conductor circuit is formed by etching, This is a method of manufacturing a printed wiring board by performing thickening by electroless plating on a through hole, a via hole, and the like on a conductor circuit. On the other hand, the full additive method uses a heat-resistant resin-based adhesive on a substrate (including ones with conductor circuits formed) or
After catalyst nuclei granted to form an adhesive layer comprising a rubber-based adhesive, a resist film prior SL adhesive layer
Then, by exposure and development or thermal curing as necessary, or by printing and curing a liquid resist, a plating resist is formed, and then electroless plating is performed on a portion where the plating resist is not formed to form a conductor pattern And
This is a method for manufacturing a printed wiring board. The present invention is characterized in that, in the above-described method for manufacturing a printed wiring board by the additive process, a heat treatment for fixing the catalyst nucleus is performed after the application of the catalyst nucleus for electroless plating.

Hereinafter, the method of the present invention according to the above-described partly additive method will be described with reference to FIG. The first step (a) in this method is to prepare a substrate 1 on which a conductor layer 2 has been formed. This substrate can be made of a metal foil such as copper foil bonded to an insulating plate, or a heat-resistant
It is preferable to form an adhesive layer for electroless plating based on a conductive resin or rubber , and then perform circuit formation by etching on a substrate or the like on which a conductor layer is deposited on the entire surface of the substrate by further performing electroless plating. . The perforation is necessary for forming the through hole 3 and the via hole. Next, the process
(b), a catalyst core 4 for electroless plating is provided on the substrate. This catalysis is provided by a colloid type solution containing Pd ions and Sn ions, such as PdCl ₂ -SnCl ₂ -HCl or
This is performed by applying a solution such as PdCl ₂ —SnCl ₂ —NaCl to at least one surface of the substrate. Next, step (c)
Is a heat treatment step for fixing catalyst nuclei specific to the method of the present invention. This processing step is performed on the substrate 1 provided with the catalyst nucleus.
Is heated under an inert atmosphere such as argon or nitrogen or under an oxygen concentration that does not cause oxidation of the catalyst core. Thereby, the catalyst core is firmly fixed to the substrate. Step (d) is a step of forming a plating resist for pattern formation. That is, in this case, after the etching resist 5 is formed, the catalyst nuclei 4 'and the conductor layer 2 other than the resist part (pattern part) are removed.
This is the step of removing. Etching resist used 5
Examples thereof include organic compound resists such as dry film photoresists, liquid photoresists, screen printing inks, electrodeposition resists, and metallic resists such as solder and gold. In addition, as an etching solution,
Aqueous solutions such as copper, ferric chloride, persulfates, hydrogen peroxide / sulfuric acid, and alkaline etchants can be used.
The step (e) is a step of forming a conductor circuit 6 by applying electroless plating to a pattern area formed by etching in the step (d). The formation of the electroless plating film serving as the conductor circuit 6 is based on, for example, a copper salt serving as a second copper ion source, and a reducing agent for converting copper ions into metallic copper, an alkaline solution for effectively using the reducing agent. It is desirable to use a pH adjusting agent for adjusting the pH, a complexing agent for preventing the precipitation of copper in an alkaline solution, a stabilizer and the like, if necessary.

Next, a case where the method of the present invention is carried out by a full additive method will be described with reference to FIG. The selection of the substrate and the method of the electroless plating are the same as those of the above-described partly additive method. In the step (a), the roughened adhesive layer 7 is formed on the substrate 1
In (b), a catalyst core 4 is applied to the surface of the roughened adhesive layer 7, and then, in step (c), the catalyst core 4 is heated and fixed, and in step (d), the catalyst core 4 is fixed. In this method, a plating resist 8 is formed on the catalyst nuclei 4 ', and then electroless plating is performed in a step (e). Therefore, the following description will focus on the step of forming an adhesive layer on a substrate unique to the full additive method.

The adhesive for forming the adhesive layer 7 on the substrate 1 is made of a heat-resistant resin which is hardly soluble in an acid or an oxidizing agent. A mixture of resin particles and heat-resistant resin fine powder having an average particle size of 2 μm or less,
(B) pseudo particles obtained by adhering heat-resistant resin 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 to 10 μm or less; (c) heat-resistant resin fine particles having an average particle size of 2 μm or less. Agglomerated particles obtained by agglomerating powder to have an average particle diameter of 2 to 10 μm, and heat-resistant particles, which are soluble in at least one kind of acid or oxidizing agent selected from the group and are cured, are preferably dispersed. It is.

The reason why such an adhesive layer is used is that it is convenient to uniformly roughen the surface of the adhesive layer. That is, in the case of such an adhesive used in the present invention, the heat-resistant resin forming the matrix with the heat-resistant particles is:
Due to the large difference in solubility in acid and oxidizing agents, only the heat-resistant particles dispersed on the surface of the adhesive layer are preferentially dissolved and removed when treated with acid or oxidizing agent. To form a concave anchor.
Therefore, the surface of the adhesive layer after treatment with an acid or an oxidizing agent is uniformly roughened due to the removed heat-resistant particles, and is an effective anchor for a conductor circuit to be formed on the surface later. Act as Therefore, a plated conductor circuit formed by the full additive method has high adhesion strength and ensures reliability. The preferred thickness of this adhesive layer is preferably 5 to 150 μm, more preferably 5 to 50 μm.
m is preferred.

As the heat-resistant particles in the adhesive, use is made of a resin having excellent heat resistance and electrical insulation properties and exhibiting properties stable to chemicals other than the oxidizing agent. The resin is hardly soluble in a heat-resistant resin liquid or a solvent by a curing treatment, but a resin that is soluble in an acid or an oxidizing agent is used.

The resin constituting such heat-resistant particles includes, for example, at least one selected from epoxy resins, polyester resins, and bismaleimide-triazine resins, with epoxy resins being particularly preferred.

Chromic acid, chromate, permanganate, ozone and the like are used as the oxidizing agent used in the above oxidation treatment.

In this method, it is desirable that, of the plated conductor circuit 9 formed on the adhesive layer, the plating resist for at least the pad portion is left as a permanent resist 8 ′ thicker than the conductor circuit 9. . The reason for this is that the relatively thick permanent resist 8 ′ prevents the solder bridge and the self-alignment effect.
(Even when the lead component is mounted on the pad, even if the lead and the pad are slightly displaced from each other, it is possible to expect the effect that the step can be accurately performed by the step between the pad and the resist or the surface tension of the solder).

Further, as the adhesive of the present invention, it is possible further use of a rubber-based adhesive such as the following. This rubber system
As an example of the adhesive, a resin, a binder, and a synthetic rubber are preferable. An epoxy resin is used as the resin, a phenol resin is used as the binder, and a diene rubber is used as the synthetic rubber. When a resin, a binder, and a synthetic rubber are mixed and melted, the resin or the synthetic rubber is in a bead state due to a difference in SP value (solubility parameter), and the resin or the synthetic rubber can be filled by cooling. it can. In addition, a chromium mixed acid is used as a roughening agent.

In the step (b), the treatment for applying the catalyst core 4 for electroless plating on the roughened adhesive layer 7 obtained in the step (a) is performed by 1
Pd ion, colloid type solution containing Sn ions, for example, PdCl ₂ -SnCl ₂ -HCl or PdCl ₂ -SnCl ₂ -NaCl, by immersion in a solution such as the surface of the plated substrate
This is performed by adsorbing Sn ions and Pd ions.

Further, after this treatment, if necessary, the surface is treated with hydrochloric acid or the like, as shown in FIG. Sn
It is preferable to perform an activation treatment for removing a part of the Pd to expose a large amount of Pd. At this time, the reason for using a colloidal catalyst as the catalyst is, for example, that the Pd compound alone is not liquefied due to its poor solubility and has a low adsorptivity to the resin, and the reason for using the Pd-Sn-based catalyst is as follows. This is because the Sn compound acts as a reducing agent and reduces Pd ions.

Next, the substrate which has been subjected to the activation treatment with hydrochloric acid or the like after the application of the catalyst nucleus is provided with the catalyst nucleus 4 as described above.
For fixing, heating is performed in a non-oxidizing atmosphere at 50 to 300 ° C. This heat treatment needs to be performed before forming the plating resist. The reason is that the catalyst nuclei 4 are easily detached during the development process for forming the plating resist.

With respect to the substrate after the catalyst core 4 has been applied,
Next, a resist film is formed in accordance with a predetermined pattern, and after exposure processing such as ultraviolet exposure or laser exposure, development is performed, or a plating resist is formed by printing or coating. Thereafter, an ultraviolet treatment or a heat treatment is further performed as necessary. For example, for UV treatment, a dose of 5 J / cm ² is desirable,
The plating resist is thermally cured by heating for 30 minutes.

In the step (d) of forming the plating resist, a chemical used for development includes chlorocene (registered trademark ) comprising 1,1,1-trichloroethane and a stabilizer.
Isopropyl alcohol, ethanol, butanol,
Use modified chlorocene (registered trademark) containing 1 to 20% of propanol + toluene, butanol + ethanol, methyl cellosolve, butyl cellosolve, methyl cellosolve acetate, methyl ethyl ketone, cyclohexane, or sodium carbonate or sodium metasilicate Can be.

Among them, modified chlorocene (registered trademark) has a stronger dissolving power than the above-mentioned chlorocene (registered trademark) , and is useful for completely removing the resist remaining in the anchor of the electroless plating adhesive layer. is there. In this regard, if the development residue of the plating resist remains in the anchor on the adhesive layer, the peel strength tends to decrease, which is not preferable. The development is preferably performed for 30 to 120 seconds.

In the present invention, it is particularly effective to wash with hot water after the exposure, development or thermal curing treatment and before the next electroless plating step (e). That is, this hot water washing process is a method of washing (hot water washing) the surface of the above-mentioned adhesive layer with hot water at 50 to 100 ° C. The reason for performing such hot water washing at this stage is to prevent the heat treatment in the preceding stage from evaporating the water on the surface of the adhesive layer and thereby reducing the wettability to the plating solution and the peel strength. Because you can.

Further, in the present invention, a step of forming a conductor pattern by performing electroless plating on the pattern of the substrate obtained through the above process. The bath for electroless copper plating used in this step is based on a copper salt serving as a source of cupric ions, and a reducing agent for converting copper ions into metallic copper, and an alkaline solution that effectively uses the reducing agent. in order to
A pH adjuster, a complexing agent for preventing precipitation of copper in an alkaline solution, a stabilizer, and the like are added as necessary.

For example, copper salt: 0.01 to 0.15 mol / l, reducing agent 0.1 mol / l, pH adjuster: 0.1 to 1 mol / l, complexing agent is in the range of 1 to 3 times the molar concentration of copper ions. It is preferable to adjust the above. The temperature of the electroless copper plating bath is 80
If the temperature is higher than 0 ° C, the bath is decomposed. If the temperature is lower than 30 ° C, the deposition rate is too slow and it takes too much time to obtain a desired electroless copper plating thickness.

[0035]

EXAMPLES Example 1 (1) The surface of an FR-4 grade insulating plate (manufactured by Hitachi Chemical Co., Ltd.) was buffed, washed with water and dried to obtain a substrate. (2) 60 parts by weight of phenol novolak type epoxy resin (manufactured by Yuka Shell), 40 parts by weight of bisphenol A type epoxy resin (manufactured by Yuka Shell), 5 parts by weight of imidazole hardener (manufactured by Shikoku Chemicals), crude for anchor formation Epoxy resin powder (manufactured by Toray, average particle size 5.5 μm) 25 as particles and fine powder
Parts by weight and epoxy resin powder (Toray, average particle size 0.5
μm) The viscosity was adjusted to 120 cps with a homodisper disperser while adding a butyl cellosolve acetate solvent to 10 parts by weight, and kneaded with a three-roll mill to obtain an adhesive.

(3) After applying the adhesive obtained in the above step (2) to the substrate obtained in the above step (1) using a roller coater, the adhesive is applied at 100 ° C. for 1 hour, 5 at ℃
By drying for an hour, an adhesive layer having a thickness of 30 μm was formed on the substrate. (4) The substrate having the adhesive layer obtained in the treatment of the (3) step is immersed in an oxidizing solution composed of an aqueous solution of chromic acid (Cr ₂ O ₃ ) 700 g / l at 70 ° C. for 15 minutes. Then, the surface of the adhesive layer was roughened, and then immersed in a neutralizing solution (manufactured by Shipley) and washed with water. (5) A colloidal tin-palladium catalyst (manufactured by Shipley Co., Ltd.) is provided on the adhesive layer of the substrate obtained in the step (4).
Was given. Then, a part of Sn was removed with an activation bath (manufactured by Shipley). (6) The substrate obtained in the process (5) was subjected to a heat treatment at 120 ° C. for 30 minutes in a high-temperature device in a non-oxidizing atmosphere replaced with N ₂ gas. The oxygen concentration at this time was 10 ppm.

(7) A dry film photoresist is laminated on the adhesive layer of the substrate obtained in the processing of the above (6) step, and after exposure, chlorocene (registered) is sprayed with a spray developing machine.
R) to IPA (isopropyl alcohol) 10%
Develop with the added modified Chlorocene (registered trademark) solution,
A plating resist having a thickness of 50 μm was formed. (8) Further, after photo-curing with an ultraviolet irradiation device at a light amount of ³ J / cm ² , heat curing was performed at 150 ° C. for 30 minutes in an oxygen-free atmosphere high-temperature chamber replaced with N ₂ gas. The oxygen concentration at this time is 15
ppm. (9) The substrate obtained in the process of the above (8) is heated at 70 ° C.
After rinsing with hot water for a minute, it was immersed again in an activation bath (manufactured by Shipley Co., Ltd.), activated, and then washed with water.

(10) The substrate obtained in the process (9) is immersed in an electroless copper plating solution for an additive method having the following composition for about 1 hour to form a plating film having a thickness of 25 μm. The printed circuit wiring board was manufactured by electroless copper plating. Copper sulfate _{(CuSO 4 · 5H 2 O)} 0.06 mol / 1 formalin (37%) 0.30 mol / 1 sodium hydroxide 0.35 mol / 1 EDTA 0.12 mol / 1 additive Some plating Concentration: 70~72 ℃ pH: 12.4

Example 2 (1) The same processing as in the steps (1) to (4) of Example 1 was performed. (2) The substrate subjected to the treatment in the step (1) was immersed in an organic complex salt-based palladium catalyst (manufactured by Schering) and washed with water. (3) The substrate after the application of the catalyst was subjected to a heat treatment at 120 ° C. for 30 minutes in a high-temperature oven in an oxygen-free atmosphere replaced with Ar gas. The oxygen concentration at this time was 3%. (4) A liquid photoresist was applied to the substrate obtained in the process of the step (3) by a roller coater, exposed and developed to form a plating resist. (5) Further, after light-curing with an ultraviolet irradiation device at a light amount of 1 J / cm ² , heat curing was performed at 150 ° C. for 30 minutes in Ar (O ₂ : 1%) gas. (6) The substrate obtained in the step (5) is heated at 50 ° C.
After rinsing with hot water, the product was immersed in an activation bath (manufactured by Schering Co., Ltd.), activated, and then washed with water. (7) Electroless plating was performed in the same manner as in the step (10) of Example 1.

Example 3 (1) The same processing as in step (1) of Example 1 was performed, and the surface of the obtained substrate was roughened. (2) Bisphenol F type epoxy resin (made by Yuka Shell)
100 parts by weight, acrylonitrile-butadiene copolymer rubber (manufactured by Goodrich Co.), 0.2 parts by weight of triphenylsulfophosphine as a conversion catalyst, 5 parts by weight of dicyandiamide,
And 0.2 parts by weight of 2-heptadecyl imidazole are dissolved in a dimethylformamide solvent to give a viscosity of 200 cps.
Was adjusted. (3) An adhesive layer was formed on the substrate by performing the same processing as in the step (3) of Example 1. (4) The substrate obtained in the treatment of the step (3) was treated with chromic sulfuric acid (sodium dichromate 120 g / 1, concentrated sulfuric acid 600 ml /
1) In an oxidizing agent solution composed of an aqueous solution, a roughening treatment was performed at 50 ° C. for 3 minutes, followed by immersion in a neutralizing solution composed of an aqueous solution of sodium sulfite, followed by washing with water. (5) A catalyst was applied on the adhesive layer by performing the same operation as the treatment in the step (5) of Example 1. (6) Heat treatment was performed in non-oxidizing Xe gas (300 ppm O ₂ ) at 120 ° C. for 30 minutes. (7) A thermosetting liquid resist was printed by screen printing on the substrate obtained in the process (6), and then heat-treated to cure to form a plating resist. (8) The substrate obtained in the process of the above (7) is heated at 70 ° C.
After rinsing with hot water for 5 minutes, activation treatment was performed with 6N hydrochloric acid, followed by rinsing with water. (9) A 30 μm-thick electroless plating was performed under the same conditions as those in the process (10) of Example 1.

Example 4 (1) The surface of an FR-4 grade insulating plate was polished, washed with water,
After drying, a substrate was obtained. (2) Phenol novolak type epoxy resin 60 parts by weight, bisphenol A type epoxy resin 40 parts by weight, imidazole curing agent 5 parts by weight, epoxy resin powder (5.5 μm particle size) 25
Parts by weight and 10 parts by weight of epoxy resin powder (3.9 μm particle size)
The viscosity was adjusted to 120 cps with a homodisper disperser to obtain an adhesive. (3) The adhesive prepared in the step (2) is applied on the substrate in the step (1) with a roll coater, and then at 100 ° C. for 1 hour.
After drying at 150 ° C. for 5 hours, an adhesive layer having a thickness of 30 μm was formed. (4) The substrate obtained in the third step is treated with chromic acid 50
It was immersed in an oxidizing agent solution consisting of an aqueous solution of 0 g / l at 70 ° C. for 15 minutes to roughen the surface of the adhesive layer. (5) A colloidal tin-palladium catalyst was applied on the adhesive layer of the substrate obtained in the treatment of the above (4) step. Next, a part of Sn was removed with HCl. (6) The substrate obtained in the process (5) was subjected to a heat treatment at 120 ° C. for 30 minutes in a high-temperature container in an oxygen-free atmosphere replaced with N ₂ gas to perform a catalyst fixing treatment. (7) Then, a dry film for plating resist was laminated, exposed, and developed with chlorocene with a spray developing machine to form a plating resist having a thickness of 50 μm. (8) Furthermore, after photocuring with a UV cure at a light amount of ³ J / cm ² , the substrate was heated in a nitrogen gas at 150 ° C. for 30 minutes. The oxygen concentration was 10 ppm. (9) The substrate obtained in the process of the (8) th step was immersed in an activating liquid, activated, and then washed with water. (10) The substrate obtained in the ninth step was treated in Example 1
The substrate was immersed in an electroless copper plating solution under the same conditions as in the step (10) for 17 hours to perform electroless copper plating with a plating film thickness of 35 μm.

Example 5 (1) The surface of an FR-4 grade insulating plate was polished, washed with water,
After drying, a substrate was obtained. (2) Phenol novolak type epoxy resin 60 parts by weight, bisphenol A type epoxy resin 40 parts by weight, imidazole curing agent 5 parts by weight, epoxy resin powder (5.5 μm particle size) 25
Parts by weight and 10 parts by weight of epoxy resin powder (3.9 μm particle size)
The viscosity was adjusted to 120 cps with a homodisper disperser to obtain an adhesive. (3) The above adhesive was applied on the substrate by a roll coater, and then dried at 100 ° C. for 1 hour and at 150 ° C. for 5 hours to form an adhesive layer having a thickness of 30 μm on the substrate. (4) The substrate obtained in the step (3) is treated with chromic acid.
It was immersed in an oxidizing agent solution consisting of a 500 g / l aqueous solution at 70 ° C. for 15 minutes to roughen the surface of the adhesive layer. (5) A colloidal tin-palladium catalyst was applied on the adhesive layer on the substrate obtained in the treatment of the above (4) step. Then, part of Sn was removed in an activation bath. (6) The substrate obtained in the process (5) was subjected to a catalyst fixing treatment at 120 ° C. for 30 minutes in a high-temperature vessel in an oxygen-free atmosphere replaced with N ₂ gas. (7) Next, a dry film for plating resist is laminated, and after exposure, chlorocene (registered) is
Recording trademark) in IPA (modified Kurorosen added isopropyl alcohol) 10% (by developing with TM) solution, the thickness
A 50 μm plating resist was formed. (8) Furthermore, after photocuring with a UV cure at a light amount of ³ J / cm ² , the substrate was heated in a nitrogen gas at 150 ° C. for 30 minutes. The oxygen concentration was 10 ppm. (9) The substrate obtained in the process of the (8) th step was immersed in an activating liquid, activated, and then washed with water. (10) The substrate obtained in the step (9) was immersed in the electroless copper plating solution used in the step (10) of Example 1 for 17 hours, and the electroless copper having a plating film thickness of 35 μm was obtained. Plating was applied.

Example 6 (1) The surface of an insulating plate of FR-4 grade was polished, washed with water,
After drying, a substrate was obtained. (2) Phenol novolak type epoxy resin 60 parts by weight, bisphenol A type epoxy resin 40 parts by weight, imidazole curing agent 5 parts by weight, epoxy resin powder (5.5 μm particle size) 25
Parts by weight and 10 parts by weight of epoxy resin powder (3.9 μm particle size)
The viscosity was adjusted to 120 cps with a homodisper disperser to obtain an adhesive. (3) The adhesive was applied on the substrate by a roll coater, and then dried at 100 ° C. for 1 hour and at 150 ° C. for 5 hours to form an adhesive layer having a thickness of 30 μm. (4) The substrate obtained in the step (3) is treated with chromic acid.
It was immersed in an oxidizing agent solution consisting of a 500 g / l aqueous solution at 70 ° C. for 15 minutes to roughen the surface of the adhesive layer. (5) A colloidal tin-palladium catalyst was applied on the adhesive layer of the substrate obtained in the treatment of the above (4) step. (6) The substrate obtained in the process (5) was subjected to a catalyst fixing treatment at 120 ° C. for 30 minutes in a high-temperature vessel in an oxygen-free atmosphere replaced with N ₂ gas. (7) Then, dry film for plating resist is laminated, and after exposure, chlorocene (registered
And developed with IPA (isopropyl alcohol) is added 10% was modified Kurorosen ® solution trademark), thickness
A 50 μm plating resist was formed. (8) Furthermore, after photocuring with a UV cure at a light amount of ³ J / cm ² , the substrate was heated in a nitrogen gas at 150 ° C. for 30 minutes. The oxygen concentration was 10 ppm. (9) The substrate obtained in the process of the above (8) is heated at 70 ° C. for 5 minutes.
After rinsing for a minute, the substrate was immersed in an activation liquid to perform an activation treatment, and then rinsed with water. (10) The substrate obtained in the treatment of the (9) step is immersed in the following electroless copper plating solution for 17 hours, and the thickness of the plating film is 35 μm.
Was subjected to electroless copper plating.

Example 7 (1) The surface of an FR-4 grade insulating plate was polished, washed with water,
After drying, a substrate was obtained. (2) Phenol novolak type epoxy resin 60 parts by weight, bisphenol A type epoxy resin 40 parts by weight, imidazole curing agent 5 parts by weight, epoxy resin powder (5.5 μm particle size) 25
Parts by weight and 10 parts by weight of epoxy resin powder (3.9 μm particle size)
The viscosity was adjusted to 120 cps with a homodisper disperser to obtain an adhesive. (3) The adhesive layer was applied on the substrate by a roll coater, and then dried at 100 ° C. for 1 hour and at 150 ° C. for 5 hours to form an adhesive layer having a thickness of 30 μm. (4) The substrate obtained in the step (3) is treated with chromic acid.
The surface of the adhesive layer was roughened by immersion in an oxidizing solution consisting of a 500 g / l aqueous solution at 70 ° C. for 15 minutes. (5) A colloidal tin-palladium catalyst was applied to the substrate obtained in the process of the above (4). (6) The substrate obtained in the process (5) was subjected to a catalyst fixing treatment at 120 ° C. for 30 minutes in a high-temperature vessel in an oxygen-free atmosphere replaced with N ₂ gas. (7) Next, a dry film for plating resist is laminated, and after exposure, chlorocene (registered) is
Recording trademark) in IPA (modified Kurorosen added isopropyl alcohol) 10% (by developing with TM) solution, the thickness
A 50 μm plating resist was formed. (8) Furthermore, after photocuring with a UV cure at a light amount of ³ J / cm ² , the substrate was heated in a nitrogen gas at 150 ° C. for 30 minutes. The oxygen concentration was 10 ppm. (9) The substrate obtained in the process of the above (8) is heated at 80 ° C.
After rinsing with hot water for 6 minutes, the substrate was immersed in a 6N hydrochloric acid aqueous solution to perform an activation treatment, and then washed with water. (10) The substrate obtained in the process of the (9) th step is treated with the same electroless copper plating solution as used in the (10) th step of Example 1.
It was immersed for 17 hours and subjected to electroless copper plating with a plating film thickness of 35 μm.

[0045] Example 8 This embodiment is basically the same as in Example 7, as a developing solution, the Kurorosen (TM), 5% propanol and cyclohexanone, respectively, the added modified Kurorosen (registered 10% (Trademark) solution was used.

Example 9 This example is basically the same as Example 4, except that a mixed solution of sodium carbonate and sodium metasilicate was used as a developing solution.

Example 10 (1) A hole diameter of 300 was formed at the position where a through hole was formed in a copper-clad laminate.
A μm hole was drilled. (2) Colloidal tin-palladium catalyst (Shipley)
Was given. (3) This substrate was subjected to a heat treatment at 120 ° C. for 30 minutes in a high-temperature vessel in a non-oxidizing atmosphere replaced with N ₂ gas to fix the catalyst core. (4) After electrodeposition of the electrodeposited photoresist on the substrate, exposure and development were performed to form an etching resist. (5) The conductor circuit was immersed in an aqueous ferric chloride solution and etched to form a conductor circuit having a thin film thickness (18 μm). (6) A plating resist was formed using a liquid photoresist except for external connection terminal portions and through holes. (7) After the substrate was washed with hot water at 70 ° C. for 5 minutes, it was immersed in an activation bath (Shipley Co., Ltd.), activated, and then washed with water. (8) Electroless plating was performed to thicken external connection terminal portions and through holes. The printed wiring board obtained in this manner has high quality without copper drop (the separated catalyst nuclei are re-adhered to a portion where the electroless plating film should not be originally deposited and copper is deposited). A printed wiring board was obtained.

Example 11 This example is basically the same as Example 1, except that after the adhesive layer was cured, the surface was polished and roughened with 6N hydrochloric acid to obtain a printed wiring board. Was.

Example 12 This example is basically the same as Example 1, except that silica (diameter: 0.6 μm) was used as the heat-resistant fine powder in the adhesive instead of epoxy resin particles. Was roughened with hydrofluoric acid to obtain a printed wiring board.

Comparative Example (1) The surface of an insulating plate of FR-4 grade was polished, washed with water,
After drying, a substrate was obtained. (2) Phenol novolak type epoxy resin 60 parts by weight, bisphenol A type epoxy resin 40 parts by weight, imidazole curing agent 5 parts by weight, epoxy resin powder (5.5 μm particle size) 25
Parts by weight and 10 parts by weight of epoxy resin powder (3.9 μm particle size)
The viscosity was adjusted to 120 cps with a homodisper disperser to obtain an adhesive. (3) The adhesive was applied on the substrate by a roll coater, and dried at 100 ° C. for 1 hour and at 150 ° C. for 5 hours to form an adhesive layer having a thickness of 30 μm. (4) The substrate obtained in the step (3) is treated with chromic acid.
It was immersed in an oxidizing agent solution consisting of a 500 g / l aqueous solution at 70 ° C. for 15 minutes to roughen the surface of the adhesive layer. (5) A colloidal tin-palladium catalyst was applied to the substrate obtained in the process of the above (4). (6) The substrate obtained in the step (5) was subjected to a heat treatment for fixing the catalyst at 120 ° C. for 30 minutes in a high-temperature container under an air atmosphere. (7) Then, dry film for plating resist is laminated, and after exposure, chlorocene (registered
(Trademark) to form a plating resist having a thickness of 50 μm. (8) Furthermore, after photocuring with a UV cure at a light amount of ³ J / cm ² , a heat curing treatment was performed at 150 ° C. for 30 minutes in an air atmosphere. (9) The substrate obtained in the process of the above (8) step was immersed in an activating liquid, activated, and then washed with water.

(10) The substrate obtained in the process of the above (9) step was immersed in the following electroless copper plating solution for 17 hours, and electroless copper plating with a plating film thickness of 35 μm was performed. Copper sulfate 0.06 mol / l Formalin 0.30 mol / l Sodium hydroxide 0.35 mol / l EDTA 0.12 mol / l Plating concentration: 70-72 ° C pH: 12.4

With respect to the printed wiring boards manufactured in Examples 1 to 9 and Comparative Example as described above, the adhesion strength between the substrate and the copper plating was measured by the method of JIS-C-6481. A table of the peel strength is shown in Table 1.

[0053]

As described above, according to the present invention, the activation of the applied catalyst is reliably achieved, so that electroless plating with high peel strength can be performed, and therefore, a highly reliable printed wiring board can be obtained. Effective for manufacturing. Moreover,
An extremely high peel strength can be obtained because the anchor effect of the adhesive is improved by development with modified chlorocene or washing with hot water.

[Brief description of the drawings]

FIG. 1 is a process chart showing the method of the present invention according to the partly additive method.

FIG. 2 is a process chart showing the method of the present invention according to the full additive method.

FIG. 3 is a process chart for activating a catalyst nucleus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Conductive layer 3 Through hole 4, 4 'Catalyst nucleus 5 Etching resist 6 Conductor circuit 7 Adhesive layer 8 Plating resist 8' Permanent resist 9 Conductor circuit

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H05K 3/10-3/26 H05K 3/38

Claims (4)

(57) [Claims] 1. A metal foil and / or a heat-resistant resin-based adhesive or a rubber-based adhesive on at least one surface thereof.
Bonding on a substrate on which an adhesive layer made of
The catalyst nuclei imparted onto adhesive layer, then facilities electroless plating
In the method of manufacturing a printed wiring board, the substrate after the catalyst nucleus is applied in a non-oxidizing atmosphere by 50 to 30
Method for manufacturing a printed wiring board, characterized by a heat treatment at 0 ℃ temperature. 2. The method according to claim 1, wherein a through hole or a via hole is formed on the substrate. 3. The printed wiring board according to claim 1, wherein the substrate to which the catalyst nucleus has been applied is heat-treated in a non-oxidizing atmosphere, a plating resist is formed, and then electroless plating is performed. Manufacturing method. 4. The method for manufacturing a printed wiring board according to claim 1, wherein a hot water washing process at 50 to 100 ° C. is performed before the electroless plating process.