JP2001203464A - Buildup multilayer printed wiring board and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multilayer printed wiring board in which a process can be simplified, where the formation property of a fine interconnection is superior and in which there is no dredge from electroless nickel/gold plating operation, whose productivity is superior, and which is suitable for the fine interconnection, and to provide its manufacturing method. SOLUTION: In the buildup multilayer printed wearing board, a plated resist is formed on substrate copper, a pattern plating operation is performed, the plated resist is stripped, the substrate copper is removed, a circuit is formed, and the electroless nickel/gold plating operation is executed. As the substrate copper, a composite metal foil which has an intermediate layer between carrier copper and substrate copper is used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a build-up multilayer printed wiring board and a method for manufacturing the same.

[Prior art]

In recent years, the miniaturization, weight reduction, and multi-functionality of electronic devices have been further advanced, and with this, the integration of LSIs and chip components has been advanced, and the form has been rapidly increased to multi-pin and miniaturized. Has changed. For this reason, a multilayer printed wiring board has been required to further increase the wiring pattern density in order to increase the mounting density of electronic components. In order to satisfy these demands, thinning between layers, miniaturization of wiring, and reduction in diameter of interlayer connection holes are performed, and an interstitial via ball (hereinafter, referred to as IVH) that connects only conductors between adjacent layers. ) And buried via balls (hereinafter,
It is called BVH. ) Is used and this IVH
And BVH are also being reduced in diameter. In order to multi-layer wiring, usually, a plurality of circuit layers and an interlayer insulating layer therebetween are collectively laminated, laminated by laminating by applying heat and pressure, and a circuit is formed by forming a circuit with a multi-layer wiring board for forming a hole at a required position and connecting. There is a build-up multilayer wiring board in which an interlayer insulating layer is formed thereon, a circuit is further formed thereon, holes are provided in necessary places, and a circuit layer and an insulating layer are sequentially formed. As an example of a build-up multilayer wiring board, a thermosetting resin is buried in a through hole of an inner layer circuit board in which a plated through hole and an inner layer circuit are formed by a silk screen printing method or the like so that the hole is closed, and heated. After curing, remove the resin protruding from the hole by polishing etc., apply thermosetting resin,
The insulating layer was formed by heating and curing, and a hole for interlayer connection was provided by selectively removing a part of the insulating layer, and the inner wall of the hole for interlayer connection was metallized by electroless plating or the like. Then, a circuit is formed by forming a plating resist on the substrate surface, removing the plating resist after pattern electroplating, and etching the underlying copper plating by quick etching. If this circuit is formed as an inner layer circuit board, one more insulating layer and circuit layer can be formed by the same operation as above, and by repeating this,
The required multilayer circuit can be formed.

[0003]

In such a build-up multilayer wiring board, after etching the underlying copper plating to form a circuit, the surface treatment of electroless nickel / gold plating is suppressed and the ion migration property is improved. Therefore, it is necessary to remove palladium, which is a catalyst for electroless copper plating. However, when a palladium stripping agent or a permanganic acid roughening agent is used, the yield is reduced due to the problem of thinning of the wiring and peeling of the wiring. The present invention provides a multilayer printed wiring board which can simplify a process, has excellent formability of fine wiring, does not have electroless nickel / gold plating, has excellent productivity, is suitable for fine wiring, and a method for manufacturing the same. The purpose is to:

[0004]

That is, the present invention provides a method for forming a plating resist on an underlying copper, performing pattern plating,
A build-up multilayer printed wiring board consisting of removing a base resist, removing a base copper, forming a circuit, and then applying electroless nickel gold plating, has an intermediate layer as a base copper between the carrier copper and the base copper The present invention relates to a build-up multilayer printed wiring board characterized by using a composite metal foil. The build-up multilayer printed wiring board of the present invention is a build-up multilayer printed wiring board in which an inner layer substrate has a through hole, and an insulating layer in which a via hole is formed on the inner layer substrate and a conductive circuit are laminated. The through-hole is filled with the same insulating resin as the build-up layer, and a composite metal foil having an intermediate layer between carrier copper and base copper is used.

Further, such a build-up multilayer printed wiring board is manufactured by performing the following steps in this order. a1 An electrically insulating ceramic whisker is blended with a thermosetting resin varnish, and after uniformly dispersing, a base copper layer having a thickness suitable for bonding to the resin and having a thickness of 0.1 to 1.0 μm is formed. A 10-150 μm-thick carrier copper layer having sufficient strength for handling as a whole metal layer;
A thermosetting resin layer is applied to a roughened surface of an underlying copper layer of a composite metal foil made of a nickel-phosphorus alloy layer having a thickness of 0.04 to 1.5 μm provided in the middle of the layer, and heated and semi-cured to form a thermosetting resin layer And a step of laminating the thermosetting resin layer on the inner layer plate on which the plated through holes and the first conductor circuit are formed in advance, and heating and pressurizing to laminate and integrate. a2 Step of removing only the carrier layer. a3 Step of removing only the nickel-phosphorus alloy layer. b. A step of irradiating the shape of the hole for forming the IVH with a laser beam until the circuit conductor of the inner layer plate is exposed to form a via hole. (c) a step of roughening the cured thermosetting resin layer on the via hole wall surface using a roughening agent; d. a step of performing electroless copper plating to electrically connect the inner layer circuit conductor and the copper foil. e forming a plating resist on the copper foil, performing an electrolytic copper plating on a space formed by the plating resist,
Forming a second conductive circuit; f. removing the plating resist. g Step of removing the underlying copper plating. h Step of forming irregularities on the surface of the conductor circuit to increase the adhesive strength between the layers. a step of forming a build-up layer by repeating the steps from ia to h as many times as necessary. j A step of forming a solder resist. k Process of applying electroless nickel / gold plating.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (Thermosetting resin) As the thermosetting resin of the present invention, various resins can be used.
A resin not exceeding 000, epoxy resin, bistriazine resin, polyimide resin, phenolic resin,
Examples include melamine resins, silicon resins, unsaturated polyester resins, cyanate ester resins, isocyanate resins, and modified resins thereof. Among them, epoxy resin, bistriazine resin and polyimide resin have Tg elastic modulus,
High hardness is preferable. As the epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, phenol novolak epoxy resin, cresol novolak epoxy resin, bisphenol A novolak epoxy resin, salicylaldehyde novolak epoxy resin, bisphenol F novolak epoxy resin, Alicyclic epoxy resin, glycidyl ester type epoxy resin, glycidylamine type epoxy resin, hydantoin type epoxy resin, isocyanurate type epoxy resin, aliphatic cyclic epoxy resin and those selected from halides and hydrogenated products thereof It can be used and can be used together. Among them, bisphenol A novolak type epoxy resin and salicylaldehyde novolak type epoxy resin are preferable because of their excellent heat resistance.

(Electrically Insulating Ceramic Whisker) The electrically insulative ceramic whisker used in the present invention must have an elastic modulus of 200 MPa or more. If the elasticity is less than 200 MPa, the rigidity is insufficient and the plate thickness is small. The warpage is large and the mountability on the motherboard is reduced. For such an electrically insulating ceramic whisker, for example, aluminum borate, wollastonite, potassium titanate, basic magnesium sulfate, silicon nitride, and α-alumina can be used. Among them, aluminum borate and potassium titanate have the same Mohs hardness as the conventional E glass, and the same wire bonding property as that of the conventional prepreg is obtained.Furthermore, aluminum borate has a high elastic modulus of 400 MPa. It is preferable because it is easily mixed with varnish. The shape of the electrically insulating ceramic whisker must have an average diameter of 0.3 to 3 μm and an average length of at least five times the average diameter. When the average diameter is less than 0.3 μm, mixing with the resin varnish becomes difficult, and when the average diameter exceeds 3 μm, dispersion in the resin is not sufficient, and the unevenness of the applied surface becomes large, which is not preferable. This average diameter is more preferably in the range of 0.3 to 1 μm. When the average length is less than 5 times, the rigidity of the resin cannot be obtained, and more preferably 20 times or more. Further, the upper limit is preferably 30 μm or less, and it is necessary that this numerical value be smaller than the circuit interval of the inner layer circuit, and at present, there is no circuit in which the inner layer circuit interval is less than 30 μm. If the average length exceeds the interval between the inner layer circuits, when the two circuits are in contact with each other, ion migration of copper is likely to occur along the electrically insulating ceramic whisker, and the possibility of short circuit is high, which is not preferable. . In order to enhance the wettability between the electrically insulating ceramic whisker and the thermosetting resin, it is preferable to use a material obtained by treating the surface of the electrically insulating ceramic whisker with a coupling agent. Are silicon-based coupling agents, titanium-based coupling agents, aluminum-based coupling agents, zirconium-based coupling agents, zirconaluminum-based coupling agents,
It can be selected from chromium-based coupling agents, boron-based coupling agents, phosphorus-based coupling agents, amino-based coupling agents, and the like.

(Curing agent) As the curing agent used for the thermosetting resin of the present invention, any curing agent can be used as long as it is used for the above-mentioned resin. For example, when an epoxy resin is used for the resin, Dicyandiamide, bisphenol A, bisphenol F, polyvinyl phenol resin, novolak resin, and bisphenol A novolak resin are preferred because of their excellent heat resistance. The compounding ratio of this curing agent to the thermosetting resin is preferably in the range of 2 to 100 parts by weight, based on 100 parts by weight of the thermosetting resin, and in the case of dicyandiamide, 2 to 5 parts by weight, In the case of the above-mentioned curing agent, the range of 30 to 80 parts by weight is preferable. If the amount is less than 2 parts by weight, curing will be insufficient, heat resistance will decrease, and
If the amount is more than the weight part, the electrical properties and heat resistance are reduced.

(Curing accelerator) It is desirable to further use a curing accelerator for the thermosetting resin and the curing agent of the present invention.
When the thermosetting resin is an epoxy resin, an imidazole compound, an organic phosphorus compound, a tertiary amine, a quaternary ammonium salt, or the like can be used as a curing accelerator. The compounding ratio of the curing accelerator is the same as that of the thermosetting resin 10
The range is preferably 0.01 to 20 parts by weight, more preferably 0.1 to 1.0 part by weight, based on 0 parts by weight. 0.0
If the amount is less than 1 part by weight, curing will be insufficient and the heat resistance will be reduced. If it exceeds 20 parts by weight, the life of the B stage will be shortened and the heat resistance will be reduced.

(Diluent) The thermosetting resin, the electrically insulating ceramic whisker, the curing agent, and the curing accelerator are used after being diluted with a solvent. As the solvent, acetone, methyl ethyl ketone, toluene, xylene, methyl isobutylene, ethyl acetate, ethylene glycol monomethyl ether, methanol, N, N-dimethylformamide, N, N-dimethylacetamide and the like can be used. The mixing ratio of the diluent to the thermosetting resin is 10%.
The range of 1 to 200 parts by weight relative to 0 parts by weight is preferable,
A range of 30 to 100 parts by weight is more preferable. When the amount is less than 1 part by weight, the viscosity becomes high and coating unevenness is easily generated.
If the amount is more than 00 parts by weight, the viscosity becomes too low and the coating cannot be applied to a required thickness.

(Ratio between thermosetting resin and electrically insulating ceramic whisker) The ratio between the thermosetting resin and the electrically insulating ceramic whisker is determined by the ratio of the electrically insulating ceramic whisker in the cured thermosetting resin. It is necessary to adjust so as to be 5 to 50% by volume. Furthermore, 20-4
More preferably, it is 0% by volume. If the content is less than 5% by volume, the film-forming ability of the thermosetting resin is small, it is difficult to handle such as scattering at the time of cutting, the rigidity is low, the warpage of the substrate after chip mounting is large, and the mountability is reduced. . If it exceeds 50% by volume, in the step a1, in the heat and pressure molding, embedding in the holes and circuit intervals of the inner layer circuit board is insufficient, resulting in voids and faintness after molding, resulting in a decrease in insulation.

(Step a1) In this step, the copper foil is
To apply the thermosetting resin and the electrically insulating ceramic whisker, a solution obtained by mixing the thermosetting resin, a curing agent, a curing accelerator, and a diluent (hereinafter, referred to as a thermosetting resin varnish) A varnish in which an insulating ceramic whisker is uniformly mixed is applied, heated, and semi-cured. A blade coater, a rod coater, a knife coater,
A squeeze coater, reverse roll coater, transfer roll coater, or other coating method that can apply a shearing force in a direction parallel to the copper foil or apply a compressive force in a direction perpendicular to the surface of the copper foil can be selected. preferable.
The resin flow of the thermosetting resin varnish is 500 μm or more, and the thickness of the thermosetting resin layer after semi-curing is 25 to 1
It is preferably in the range of 00 μm. This resin flow refers to a prepreg with a copper foil having a resin thickness of 50 μm.
Drill a hole of 0 mm square, layer it so that the resin is in contact with the copper foil surface of the copper-clad laminate, and apply heat and pressure at 170 ° C. and 2.5 MPa for 60 minutes to laminate and bond the edge of the 30 mm square hole. Is the minimum distance of the resin that has flowed out to the copper foil surface.
This resin flow is preferably adjusted in the range of 500 μm to 10 mm, and if it is less than 500 μm, the embedding property of the inner layer copper foil is small, and irregularities occur on the surface.
If it exceeds, the thickness of the end portion after lamination is small, and the insulating property is reduced.

(Steps a2 and a3) In this step, when a thin copper foil is handled, in the case of a physically peelable carrier, in the handling step, the surface of the copper foil may be scratched or a foreign substance may adhere. In order to prevent this, a composite metal foil having a high adhesion is used, and a metal having a chemical removal condition different from that of the circuit conductor is used for removing the carrier. By the way, if such a metal layer is thick, it is not economical and the process becomes long. Therefore, an intermediate layer is used at a position where etching is to be stopped. As a solution for etching and removing only the carrier copper layer, a solution containing chlorine ions, ammonium ions, and copper ions (hereinafter, referred to as an alkali etchant) is used. The treatment method is immersion,
This is performed by contact with a solution such as spray. Further, in the step of removing only the nickel-phosphorus alloy, an organic acid having a carboxyl group as an additive, -NH- as a ring member, and a liquid containing nitric acid and hydrogen peroxide as main components.
This is carried out by immersing in an aqueous solution containing a nitrogen-containing heterocyclic compound in the form of -N =, or by spraying such an aqueous solution.

(Step a4) This step a4 is the same as the step a1
The insulating resin to be used in step a1 may be any material as long as it can be used as a film alone, such as an epoxy resin, a polyimide resin, a cyanate ester resin, or a polyamideimide resin. , Bismaleimide triazine resin and the like have Tg and elastic modulus,
High hardness is preferable.

(Step b) In this step, the underlying copper layer and the resin are simultaneously removed by irradiating a laser beam until the copper foil of the inner layer plate is exposed to form a via hole. The laser that can be used in this step is a carbon dioxide laser, Y
There are an AG laser, an excimer laser and the like, and a carbon dioxide gas laser is preferable in terms of productivity. The irradiation condition of the laser beam at this time is preferably such that the pulse is oscillated in a short time and has a large output.
Second, pulse repetition frequency is 150-10,000H
It is preferable to use a laser oscillator capable of producing an output capable of drilling holes with an output magnitude in the range of 2 to 5 pulses under the conditions of z and the number of repetition pulses of 1 to 10 pulses because oscillation and control are easy. This output is expressed as an energy density of 15 to 40
J / cm ² range. If the output per hour is less than the above range, the resin layer cannot be evaporated and diverged,
Beyond the above range, it is difficult to control the hole diameter becomes more than necessary, the resin once evaporated may be carbonized and adhered,
Removal of the attached carbide must be performed. The thickness of the base copper layer is preferably in the range of 0.1 to 1 μm or less, and in the range of 0.3 to 0.6 μm from the viewpoint of laser workability, pattern plating film thickness uniformity, wiring formability by quick etching, and the like. Is preferred.

(Step c) As the roughening agent used in this step, any one can be used as long as it swells and dissolves the resin. Usually, it is preferable to use an aqueous solution of alkali permanganate.

(Step d) The electroless copper plating performed in this step employs the same technique as that of ordinary through-hole plating of a wiring board. That is, a substance serving as a plating nucleus such as palladium is attached to the roughened resin layer, and an electroless plating solution having an ionized plating metal, a complexing agent for the plating metal, and a reducing agent for the plating metal. To deposit the plating metal on the entire wall. Thus, when plating is performed,
The copper foil of the outer layer, the wall surface of the IVH, and the circuit conductor of the inner layer plate can be electrically connected. The electroless copper plating performed in this step may be any thickness as long as the inner layer circuit and the substrate surface can be electrically connected, and preferably less than 1 μm,
More preferably, the thickness is 0.3 to 0.5 μm.

(Step e) In this step, a photosensitive dry film photoresist is laminated on the substrate on which the electroless plating is performed to a thickness of less than 1 μm, and a portion which becomes a circuit space is irradiated with ultraviolet rays to develop a resin in the circuit portion. Remove with liquid. The electroplating performed in this step can use a normal electroplating technique, and the plating solution includes copper cyanide plating, copper borofluoride plating, copper pyrophosphate plating, copper sulfate plating, and the like. Copper sulfate plating that is easy to manage is preferred.

(Step f) In this step, a common stripping solution such as caustic soda or monoethanolamine can be used, and monoethanolamine having high permeability is preferable.

(Step g) As the surface treatment liquid for the underlying copper and the conductor circuit in this step, various substances can be used, but an acid-based etching liquid having a low etching rate is preferable.

(Step h) As the surface treatment solution for the underlying copper and the conductor circuit in this process, various ones can be used, but a sulfuric acid / hydrogen peroxide-based, organic acid-based, and nitric acid-based etching solution having a low etching rate. Is preferred.

(Step i) A step of forming a build-up layer by repeating the steps a to h.

(Step j) As the solder resist in this step, a general thermosetting and photosensitive photo solder resist can be used, but a photo solder resist is preferable because a fine pattern can be formed.

(Step k) A commercially available electroless nickel / gold plating can be used in this step. Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited thereto.

[0025]

EXAMPLE 1 Step a1 As shown in FIG. 1 (a), MCL-E-67, a 0.4 mm thick glass cloth-epoxy resin impregnated double-sided copper-clad laminate.
9 (manufactured by Hitachi Chemical Co., Ltd., trade name)
An inner layer circuit having a through hole 101 in which electroless copper plating is performed, a thermosetting resin M-650TH (trade name, manufactured by Asahi Kaken Co., Ltd., trade name) is filled in the through hole 101 as a hole filling material, heat-cured and filled by a normal subtraction method. Plate 1 was produced. Next, as shown in FIG. 1 (b), the underlayer of the composite metal foil 3 consisting of an underlayer copper layer having a thickness of 0.5 μm / a nickel-phosphorus alloy layer having a thickness of 0.2 μm / a carrier copper layer having a thickness of 15 μm. A 30% by volume aluminum borate whisker was mixed and stirred with a thermosetting resin varnish having the following composition on the surface of the copper layer, applied with a knife coater, dried at 150 ° C. for 10 minutes, and semi-cured. An adhesive film with a copper foil having a thermosetting resin 2 having a thickness of 50 μm was produced.

(Composition of thermosetting resin varnish) bisphenol A novolak type epoxy resin (epoxy equivalent: 200) 100 parts by weight bisphenol A novolak resin (hydroxyl equivalent: 10)
6) 60 parts by weight ・ 2-ethyl-4-methylimidazole (curing agent) 0.5
100 parts by weight of methyl ethyl ketone (diluent) 100 parts by weight of the inner layer plate 1 and the adhesive film with copper foil thus prepared are brought into contact with the circuit conductors on both sides of the inner layer plate 1 and the thermosetting resin layer 2 of the adhesive film. And at 170 ° C, 6
The laminate was integrated by heating and pressing at a pressure of 2.5 MPa for 0 minutes. The resin flow under this condition was 3 mm.

Step a2 Only the carrier copper layer was removed by etching with the following alkaline etchant. (Alkali etchant composition) · Cucl ₂ ··· 175 g / 1 · NH ₄ OH ··· 154 g / 1 · NH ₄ cl ···・ ・ ・ 236g / 1 liquid temperature: 50 ℃

Step a3 Only the nickel-phosphorus alloy layer was removed by etching with the following etching solution. (Etching liquid composition) ・ Nitric acid ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ 2
00g / 1 ・ Hydrogen peroxide solution (35%) ・ ・ ・ ・ ・ ・ ・ 1
0m1 / 1 ・ Organic acid containing carboxyl group (DL-malic acid) ・ ・ ・ 1
00g / 1 · Benzotriazole 5
g 1

Step b The cured thermosetting resin layer is irradiated with carbon dioxide laser light at an energy density of 20 J / cm ² and an oscillation time of 5 μm.
Irradiation was performed for 2 seconds at an oscillation frequency of 500 Hz and 4 pulses to remove the circuit conductor of the inner layer plate until the circuit conductor was exposed, thereby forming IVH4. (FIG. 1e)

Step c The substrate surface and the IVH wall surface of the cured thermosetting resin layer are roughened at a liquid temperature of 70 ° C. for 10 minutes by using a 7% aqueous solution of alkali permanganic acid as a roughening agent. It has become.

Step d: The surface of the roughened substrate and the wall of the via hole are treated with HS-202B (trade name, manufactured by Hitachi Chemical Co., Ltd.) which is a treatment liquid for applying an electroless copper plating catalyst at room temperature for 10 minutes. The catalyst was applied to the surface of the substrate and the wall surface of the via hole by bringing the substrate into contact. The substrate was immersed in the electroless copper plating solution CUST-201 (trade name, manufactured by Hitachi Chemical Co., Ltd.) on the surface of the substrate to which the catalyst was applied and the wall surface of the via hole, and the underlying copper layer was 0.3 μm in thickness. went. Measurement of plating film thickness is SFT8
000 (manufactured by Seiko Denshi, trade name). (Figure 1
f)

Step e On the copper surface, dry film Photek RY3025
(Hitachi Chemical Industries, Ltd., trade name) was used to form a plating resist 5 in the gaps. The substrate on which the plating resist was formed was subjected to pattern electroplating 6 using a copper sulfate plating solution so that the thickness of the conductor circuit became 15 μm. (Fig. 1g)

Step f The substrate on which the electroplating has been performed is removed with a stripping solution RS-2000.
The plating resist was peeled off by using a general spray-type peeling machine under the conditions of 50 ° C. and a spray pressure of 0.2 MPa for 1 minute (trade name, manufactured by Attec). (Fig. 1h)

Step g Using a cobra etch (trade name, manufactured by Ebara Densan Co., Ltd.) as an etching solution for the underlying copper, at 30 ° C. and a spray pressure of 0.2 MPa
a The base copper was removed using a general spray etching machine under the condition of 1 minute. (FIG. 1i)

Step h CZ-81 is used as a liquid for forming irregularities on the surface of the conductor circuit.
The surface of the underlying copper and the surface of the conductor circuit were simultaneously roughened using a No. 00 (trade name, manufactured by Mec Co., Ltd.). Etching amount is 3μm
It went with the setting of.

Step i: a step of repeating steps a to h to produce a two-stage build-up substrate.

Step j A solder resist SR is formed on the surface of the two-step build-up substrate.
After printing -7000 and drying at 80 ° C. for 20 minutes, a photomask having a pattern formed so as to block ultraviolet light at a portion to be an opening is aligned, and 450 mJ / cm ^2.
, And developed with a 1.5% solution of sodium carbonate at a spray pressure of 0.2 MPa, and a post-exposure of 1 J / cm ² ,
Thereafter, heating was performed at 150 ° C. for 60 minutes to form a solder resist.

Step k Electroless nickel gold plating was performed using the following steps. Degreasing treatment: Immersion treatment in Z-200 (trade name, manufactured by World Metal Co., Ltd.) at 50 ° C. for 1 minute.・ Washing: Rinse with running water for 2 minutes at room temperature. -Soft etching: immersion treatment in 100 g / 1 ammonium persulfate at room temperature for 1 minute.・ Washing: Rinse with running water for 2 minutes at room temperature. -Pickling treatment: immersion treatment in 10% sulfuric acid at room temperature for 1 minute.・ Washing: Rinse with running water for 2 minutes at room temperature. -Activation: dipping in a catalyst solution for electroless plating SA-100 (trade name, manufactured by Hitachi Chemical Co., Ltd.) at room temperature for 5 minutes.・ Washing: Rinse with running water for 2 minutes at room temperature. -Electroless nickel plating: immersion treatment at 85 ° C for 20 minutes in NIPS-100 (trade name, manufactured by Hitachi Chemical Co., Ltd.) which is an electroless nickel plating solution. The deposition form of the electroless nickel plating film was laminar.・ Washing: Rinse with running water for 2 minutes at room temperature.・ Electroless gold plating: HGS-50 which is electroless gold plating
0 (trade name, manufactured by Hitachi Chemical Co., Ltd.) at 85 ° C. for 5 minutes.・ Washing: Rinse with running water for 2 minutes at room temperature.

Example 2 The same procedure as in Example 1 was carried out except that 10% by volume of aluminum borate whiskers were added to the thermosetting resin varnish. Example 3 A sample was prepared in the same manner as in Example 1 except that MCF-7000LX (trade name, manufactured by Hitachi Chemical Co., Ltd.) was used as a thermosetting resin which alone became a film instead of step a1.

Comparative Example 1 The procedure of Example 1 was repeated, except that the composite metal foil with resin used in step a1 was laminated with an epoxy resin having a roughening property in alkaline permanganate. Comparative example 2 It produced similarly to Example 1 except having used the copper foil with a 5 micrometer carrier instead of the composite metal foil used at process a1. Table 1 shows the results of Examples and Comparative Examples.

[0041]

[Table 1]

[0042]

As described above in detail, according to the present invention, the wiring is fine, the electroless nickel plating is not pretended, the IVH and BVH are small in diameter, the strength is excellent, and the connection reliability is excellent. The present invention can provide a multilayer printed wiring board excellent in productivity and productivity, and a method for manufacturing the same.

[Brief description of the drawings]

FIGS. 1A to 1I are cross-sectional views illustrating respective steps for explaining an embodiment of the present invention.

[Explanation of Signs] 1. Inner layer plate 2. Insulating resin layer containing electric insulating ceramic 3. Composite metal foil 4. Via hole 5. Plating resist 6. Pattern copper plating 7. Solder resist 8. Electroless nickel / gold plating 101 .Through hole 301 Base copper

Continued on the front page (51) Int.Cl. ⁷ Identification FI FI Theme Court II (Reference) // C08K 7/04 C08K 7/04 C08L 101/00 C08L 101/00 (72) Inventor Toyoki Ito Shimodate, Ibaraki 1500, Ogawa, Hitachi Chemical Co., Ltd., Research Laboratory (72) Inventor, Shigeharu Ariya, Oji, Shimodate, Ibaraki Prefecture 1500, Okayama, Hitachi Chemical Industry Co., Ltd. (72) Inventor, Akishi Nakaso, Oji, Shimodate, Ibaraki 1500 address Hitachi Chemical Industries, Ltd. Research Laboratory F-term (reference) 4E351 AA01 AA03 AA04 BB30 BB33 BB35 BB38 BB49 CC06 CC07 CC19 DD04 DD19 DD21 DD54 GG01 GG20 4J002 AA021 CC031 CC181 CD021 CD051 CD061 CD131 CD141 CF2 DECG1 DG146 DK006 FA026 FB076 FB086 FD016 FD126 FD140 FD150 FD200 GQ01 5E317 AA24 BB02 BB03 BB12 BB15 BB18 CC32 CC33 CC52 CD05 CD13 CD15 CD18 CD25 CD27 CD32 GG03 GG14 GG16 5E346 AA05 AA15 CCB CC A CC A CC D02 DD12 DD23 DD25 DD33 DD47 EE31 EE38 FF01 FF07 FF15 GG01 GG15 GG17 GG22 GG27 GG28 HH26 HH33

Claims (7)

[Claims] 1. A build-up multilayer print comprising forming a plating resist on an underlying copper, performing pattern plating, removing the plating resist, removing the underlying copper, forming a circuit, and applying electroless nickel gold plating. A build-up multilayer printed wiring board, wherein a composite metal foil having an intermediate layer between carrier copper and base copper is used as base copper. 2. The method according to claim 1, wherein the composite metal foil has a carrier copper thickness of 70 to 70%.
The build-up multilayer printed wiring board according to claim 1, wherein the build-up multilayer printed wiring board is a metal foil having a thickness of 12 μm, a thickness of a base copper of 1.0 to 0.1 μm, and an intermediate layer of 1.0 to 0.04 μm. 3. The build-up multilayer printed wiring board according to claim 1, wherein the intermediate layer is a nickel-phosphorus alloy layer. 4. A method for manufacturing a multilayer printed wiring board, comprising the steps of: a1 A thermosetting resin varnish is blended with an electrically insulating ceramic whisker, and after uniformly dispersing, a 1 to 9 μm-thick underlying copper layer having a roughness suitable for bonding with a resin, A carrier copper layer having a thickness of 10 to 150 μm having sufficient strength for handling as a metal layer, and a nickel layer having a thickness of 0.04 to 1.5 μm provided between the two layers.
Applying to the roughened surface of the underlying copper layer of the composite metal foil composed of a phosphorus alloy layer, heating and semi-curing, forming a thermosetting resin layer, and forming the plating through hole and the first conductor circuit in advance on the inner layer plate A step of laminating the thermosetting resin layer thereon, and applying heat and pressure to laminate and integrate. a2 Step of removing only the carrier layer. a3 Step of removing only the nickel-phosphorus alloy layer. b. A step of irradiating the shape of the hole for forming the IVH with a laser beam until the circuit conductor of the inner layer plate is exposed to form a via hole. (c) a step of roughening the cured thermosetting resin layer on the via hole wall surface using a roughening agent; d. a step of performing electroless copper plating to electrically connect the inner layer circuit conductor and the copper foil. e forming a plating resist on the copper foil, performing an electrolytic copper plating on a space formed by the plating resist,
Forming a second conductive circuit; f. removing the plating resist. g Step of removing the underlying copper plating. h Step of forming irregularities on the surface of the conductor circuit to increase the adhesive strength between the layers. a step of forming a build-up layer by repeating the steps from ia to h as many times as necessary. j A step of forming a solder resist. k Process of applying electroless nickel / gold plating. 5. The method for producing a build-up multilayer printed wiring board according to claim 4, wherein instead of the step a1, lamination and integration are performed by using a film containing no filler as the step a4. 6. The resin flow of the thermosetting resin is 500 μm or more, and the thickness of the thermosetting resin layer after semi-curing is 25 to 10 μm.
The method for producing a build-up multilayer printed wiring board according to claim 4 or 5, wherein the thickness is in a range of 0 µm. 7. The method for producing a multilayer printed wiring board according to claim 4, wherein the amount of the electrically insulating ceramic whisker to be mixed with the thermosetting resin is 5 to 50% by volume.