JP2000151118A - Manufacture of multilayer printed wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent signal propagation delay in a high frequency range without decreasing the adhesiveness between an interlayer resin insulation layer and a conductor circuit by bonding a specific polyolefine-system resin film formed on one face with a metal layer under heat and pressure on a substrate formed with the conductor circuit. SOLUTION: A polyolefine-system resin film formed on one face with a metal layer is bonded under heat and pressure on a circuit-formed substrate to form an interlayer insulation resin layer. As for the resin film, resin constituted of one type of repeated unit shown by a formula (where (n) is 1-10000, X is hydrogen, an alkyl group, a phenyl radical, a hydroxyl group, C2-C3 unsaturated hydrocarbon, an oxide group, or a lactone group), resin made by copolymerization of two or more types of the repeated unit shown by the formula, resin which has the repeated unit shown by the formula and which includes a double bond, etc., in a main chain of the molecule, or mixed resin made by mixing some of the resins selected from the above ones.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a multilayer printed wiring board, and more particularly to a method for manufacturing a build-up multilayer wiring board.

[0002]

2. Description of the Related Art In recent years, as one of the methods of manufacturing a multilayer printed wiring board which has been put into practical use in response to a demand for higher density of the wiring board, a resin-coated copper foil called RCC (resin coated copper) has been used. Build-up multilayer printed wiring boards have been proposed. In this method, a copper foil with a resin is heat-pressed on a conductive circuit forming substrate, an opening is formed in a part of the copper foil by etching, and the resin is removed by irradiating a laser beam through the opening to remove the resin. This is a technique in which an opening is provided and a via hole and a conductive circuit are formed by electroless plating or etching.

[0003]

The above prior art uses an epoxy resin or a polyimide resin as an interlayer resin insulating layer. However, these resins have poor adhesion to the metal layer, and therefore, it is necessary to roughen the surfaces of the resin insulating layer and the metal layer. However, when a high-frequency signal is propagated, the skin effect that propagates only on the surface of the metal causes the propagated high-frequency signal to be affected by micro-roughness on the roughened surface, causing a delay in signal propagation or impedance. There was a problem that alignment was not possible. In addition, in the case where a through hole for a via hole is provided by irradiating a laser beam to these resin insulating layers, resin tends to remain at the bottom of the hole, and the connection reliability of the via hole is reduced. .

An object of the present invention is to solve the above-mentioned problems of a resin substrate, and a main object of the present invention is to provide a high-performance resin circuit without deteriorating the adhesion between an interlayer resin insulating layer and a conductive circuit. An object of the present invention is to propose a method of manufacturing a multilayer printed wiring board that can prevent delay in signal propagation in a frequency band and improve connection reliability of via holes.

[0005]

Means for Solving the Problems The inventors of the present invention have intensively studied for realizing the above-mentioned object, and as a result, have arrived at an invention having the following content as a gist configuration. That is, in the method for manufacturing a multilayer printed wiring board according to the present invention, a resin film having a metal layer provided on one surface is heat-pressed on a substrate on which a conductive circuit is formed, and an opening is formed in a part of the metal layer. Then, a laser beam is irradiated through the opening to form a hole for a via hole in the resin layer, and thereafter, the via hole and the upper conductor circuit are formed to be connected to the lower conductor circuit. Wherein the resin film is a polyolefin-based resin. Still another invention is that a resin film having a metal layer provided on one surface is heat-pressed to a substrate on which a conductor circuit is formed, and the metal layer is irradiated with a laser beam to the metal layer and the resin film. A method for manufacturing a multilayer printed wiring board in which a hole for forming a via hole is formed, and then a via hole and a conductive circuit are formed and connected to a lower conductive circuit, wherein the resin film is a polyolefin resin. And In the present invention, a roughening layer may be provided on the upper surface of the conductor circuit formed on the substrate, or Ni, Pd, Cr, C
It is desirable to form a metal layer made of at least one metal selected from o, Pt, Ti and Au. Further, the entire surface of the conductor circuit formed on the substrate is roughened or a metal layer made of at least one metal selected from Ni, Pd, Cr, Co, Pt, Ti and Au is formed. Is desirable.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The method for manufacturing a multilayer printed wiring board according to the present invention comprises the steps of: forming a polyolefin resin film having a metal layer provided on one of its surfaces, for example, a metal foil such as copper, on a circuit forming substrate; It is characterized in that an interlayer resin insulation layer is formed by heat-pressing the adhered polyolefin-based resin film. The polyolefin resin used in the present invention is a resin having the following structure. 1． A resin comprising one type of repeating unit represented by the following structural formula.

Embedded image 2． A resin comprising a copolymer of two or more different repeating units represented by the following structural formula.

Embedded image 3． A resin having a repeating unit represented by the following structural formula and having a double bond, an oxide structure, a lactone structure, or a mono- or polycyclopentadiene structure in its molecular main chain.

Embedded image Four. A mixed resin obtained by mixing two or more resins selected from the groups of 1, 2, and 3; a mixed resin of a resin selected from the groups of 1, 2, and 3 and a thermosetting resin; Three
A resin obtained by crosslinking resins selected from the group consisting of: In the present invention, “resin” is a concept including so-called “polymer” and “oligomer”.

Hereinafter, the above-mentioned resins 1 to 3 will be described in detail. In the present invention, the reason for employing the resins 1 to 3 including the structure of the repeating unit described above is that these resins can be used as a thermosetting polyolefin without lowering the fracture toughness value. is there. Here, as the alkyl group used as X in the repeating unit, at least one selected from a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, and a t-butyl group is preferable. Examples of the unsaturated hydrocarbon C2 -C3 employed as X in the repeating _{unit, CH 2 = CH-, CH 3} CH = CH-, CH 2 =
At least one selected from C (CH ₃ ) — and an acetylene group;
More than species are desirable. The oxide group employed as X in the repeating unit is preferably an epoxy group or a propoxy group, and the lactone group is preferably a β-lactone group or γ
-Lactone groups and δ-lactone groups are desirable.

Further, X in the repeating unit is C2-C
The reason why the unsaturated hydrocarbon, oxide group, lactone group, and hydroxyl group of No. 3 are employed is that they have high reactivity and easily crosslink resins (in this case, oligomers) containing these functional groups. Further, the reason why n is set to 1 to 10,000 is that n is
If it exceeds 10,000, the solvent becomes insoluble and it becomes difficult to handle.

In the above resin 3, the double bond structure in the molecular main chain may be a repeating unit represented by the following structural formula,-(CH = CH) m- or-(CH ₂ -CH = CH
It is preferable that a repeating unit of —CH ₂ ) m— is copolymerized.
Here, m is 1 to 10,000.

Embedded image

In the resin (3), the oxide structure of the molecular main chain is preferably an epoxy structure. As the lactone structure of the molecular main chain, β-lactone and γ-lactone structures are desirable. Further, as the mono- or polycyclopentadiene of the molecular main chain, a structure selected from cyclopentadiene and bicyclopentadiene can be adopted.

In the copolymer, the repeating unit is ABAB.
..When alternating copolymerization as in the above, the repeating unit is AB
There are cases where random copolymerization such as AAABAAAAB... Or block copolymerization such as AAAAABBB.

Next, the resin 4 will be described. The resin 4 is a mixed resin obtained by mixing two or more resins selected from the groups 1, 2, and 3; a mixed resin of a resin selected from the groups 1, 2, and 3 and a thermosetting resin; or 1, 2,
Resins selected from the group 3 are cross-linked resins.
When two or more kinds of resins selected from the groups 1, 2, and 3 are mixed, the resin powder is dissolved in an organic solvent or mixed by heat melting. In addition,
When mixing a resin selected from the group of 1, 2, and 3 with a thermosetting resin, the resin powder is dissolved in an organic solvent and mixed.
As the thermosetting resin to be mixed in this case, it is desirable to use at least one or more selected from thermosetting polyolefin resins, epoxy resins, phenol resins, polyimide resins, and bismaleimide triazine (BT) resins. Further, when the resins selected from the groups 1, 2, and 3 are cross-linked to each other, a C2-C3 unsaturated hydrocarbon,
An oxide group, a lactone group, a hydroxyl group and a double bond in the molecular main chain, an oxide structure, and a lactone structure are used as bonds for crosslinking.

As a commercially available product of the thermosetting polyolefin resin used in the present invention, there is a trade name 1592 manufactured by Sumitomo 3M Limited. Commercially available thermoplastic polyolefin resins having a melting point of 200 ° C. or higher include TPX (trade name: 240 ° C.) manufactured by Mitsui Chemicals and SPS (melting point: 270 ° C.) manufactured by Idemitsu Petrochemical. TPX
Is a resin in which X in the repeating unit is an isobutyl group, and SPS is a resin in which X is a phenyl group and has a syndiotactic structure.

Since such a polyolefin resin has excellent adhesion to a conductor circuit, a conductor can be formed without roughening the surface of the resin insulating layer. That is, a conductive circuit can be formed on the surface of the flat resin insulating layer. The polyolefin resin has a dielectric constant of 3 or less and a dielectric loss tangent of 0.05 or less, which is lower than that of the epoxy resin.
There is no propagation delay even for high frequency signals. Further, the polyolefin resin has heat resistance comparable to that of the epoxy resin, and the conductor circuit does not peel even at the solder melting temperature.
Furthermore, since the fracture toughness value is large, cracks starting from the boundary between the conductor circuit and the resin insulating layer due to the heat cycle do not occur.

Hereinafter, one method of manufacturing a build-up multilayer printed wiring board according to the present invention will be described. First, a substrate having an inner copper pattern formed on the surface of a resin substrate is prepared, and then a through hole is drilled in the substrate, and a through hole is formed by performing electroless plating on the wall surface of the through hole and the copper foil surface. . Here, as the substrate, a core substrate with a foil such as a glass epoxy substrate, a polyimide substrate, a bismaleimide-triazine resin substrate, a fluorine resin substrate, or a polyolefin resin substrate can be used. Further, copper plating is preferable as the electroless plating.

Next, electrolytic plating for thickening is performed on the electroless plating layer. This electrolytic plating is preferably electrolytic copper plating. Then, a conductive circuit is formed on the substrate by etching. Next, in order to secure adhesion between the interlayer insulating layer and the copper plating film, the inner wall of the through hole and the upper surface of the electrolytic plating film (conductor circuit) or the entire surface thereof are roughened to provide a roughened layer. The roughened layer may be formed by a blackening (oxidation) -reduction treatment, a coating formed by spraying a mixed aqueous solution of an organic acid and a cupric complex, or a copper-nickel-phosphorus needle-like alloy plating. is there. Instead of roughening the surface of the conductor circuit, Pd, Ni, Cr, Co, Pt,
A method may be used in which a metal layer made of one or more metals selected from Au and Ti (including the alloy and uniformly referred to as metal) is formed on the surface of the conductive circuit.

Next, an interlayer resin insulating layer is formed on both surfaces of the wiring board after the above-described processing. In the present invention, in particular, in forming the interlayer resin insulating layer, a polyolefin resin film having a metal foil adhered to one surface is superimposed on one or both surfaces of the substrate, and is integrated by heat pressing. Copper foil is suitable as the metal foil.

Next, in order to secure electrical connection between the conductor circuit formed on the interlayer insulating layer formed using the polyolefin resin film with the metal foil and the lower conductor circuit,
Drill holes for via holes. There are the following two methods for forming the via hole opening.

A) An opening is formed by partially etching the metal foil to expose the polyolefin resin layer in the metal foil. When this opening is irradiated with a laser beam having a spot diameter larger than this diameter, the portion covered with the metal foil remains, and the exposed polyolefin resin is removed to form a via hole opening. You. In this method, even if the laser irradiation position accuracy is low, the via hole position accuracy can be ensured by ensuring the position accuracy of the opening provided in the metal foil. Etching is performed by attaching a photosensitive dry film to a metal foil,
Developed, provided etching resist, hydrogen peroxide
It is carried out by treating with an aqueous solution of sulfuric acid, an aqueous solution of cupric chloride and an aqueous solution of ammonium persulfate.

B) The thin metal foil may be directly irradiated with laser light to remove the polyolefin resin layer simultaneously with the metal foil. The thickness of the metal foil is less than 12 μm, preferably 1
10 to 10 μm is preferable. If the thickness exceeds 12 μm, the metal foil cannot be removed with an inexpensive carbon dioxide laser. In the case of using a copper foil, a copper foil having a thickness of 1 to 10 μm is easy to open with a carbon dioxide gas laser, and is optimal.

In this method, the etching step can be omitted, and the cost can be reduced. Further, since the metal foil is thin and the thermal conductivity is small, there is an advantage that the amount of resin remaining in the opening can be reduced.

The metal foil used in the present invention is preferably a copper foil, an aluminum foil, a nickel foil, or a noble metal foil, and most preferably, a copper foil.

The laser light used includes a carbon dioxide laser, an ultraviolet laser, an excimer laser, and the like. As the carbon dioxide gas laser, a short pulse laser is optimal, and the pulse time is desirably 10 ^-4 to 10 ^-8 seconds. As such a laser beam machine, ML605GTL (trade name) manufactured by Mitsubishi Electric can be used.

After drilling the opening in the manner described above,
Desmear processing may be performed. This desmearing treatment can be performed using an oxidizing agent composed of an aqueous solution such as chromic acid or permanganate, or may be treated by oxygen plasma, mixed plasma of CF ₄ and oxygen, corona discharge, or the like. In addition, a method of irradiating ultraviolet rays using a low-pressure mercury lamp to perform treatment may be used.

Next, the metal foil on the polyolefin resin film is further subjected to electroless plating, if necessary, to form an electroless plated film. This electroless plating is optimally copper plating, and the thickness of the electroless plating film is preferably 0.1 μm to 1 μm.

Next, a plating resist is formed on the metal foil or the electroless plating film. This plating resist is formed by laminating a photosensitive dry film, exposing, and developing.

Then, electrolytic plating is performed to thicken the conductor portion of the resin opening and the upper conductor circuit.
Further, after removing the plating resist, a conductor circuit is formed by etching. Sulfuric acid-
An aqueous solution of hydrogen peroxide, an aqueous solution of persulfate such as ammonium persulfate, sodium persulfate or potassium persulfate, or an aqueous solution of ferric chloride or cupric chloride is preferred.

Further, the surface of the conductor circuit formed by the above is subjected to a roughening treatment to provide a roughened layer. In the present invention, instead of the conductor circuit surface and the roughened surface, Pd, N
1 selected from i, Cr, Co, Pt, Au and Ti
A metal layer made of at least one kind of metal is formed. In this way, by repeating the above steps as necessary, a build-up multilayer printed wiring board is manufactured.

Hereinafter, preferred embodiments of the present invention will be described based on examples.

[Electroless plating aqueous solution]

 EDTA 150 g / l Copper sulfate 20 g / l HCHO 30 ml / l NaOH 40 g / l α, α'-bipyridyl 80 mg / l PEG 0.1 g / l [Electroless plating conditions] 30 minutes at a liquid temperature of 70 ° C.

Further, electrolytic copper plating was performed with an aqueous electrolytic plating solution having the following composition under the following conditions to form an electrolytic copper plating film having a thickness of 15 μm (see FIG. 1 (c)). [Electroplating aqueous solution] Sulfuric acid 180 g / l Copper sulfate 80 g / l Additive (manufactured by Atotech Japan, trade name: Capparaside GL) 1 ml / l [Electroplating conditions] Current density 1 A / dm ² hours 30 minutes Temperature Room temperature

(2) The substrate 1 on which the inner layer copper pattern 2 (including the through hole 3) has been formed is washed with water and dried, and then used as an oxidation bath (blackening bath) as NaOH (20 g / l), NaClO ₂
(50 g / l) and an aqueous solution of Na ₃ PO ₄ (15.0 g / l)
NaOH (2.7 g / l), NaBH ₄ (1.0 g /
1) subject to oxidation-reduction treatment using an aqueous solution of
A roughened layer 4 was provided on the entire surface of the through hole (see FIG. 1 (d)).

(3) The conductive paste 5 containing copper particles was filled in the through holes 3 by screen printing, dried and cured. Then, the conductive paste 5 protruding from the roughened layer 4 and the through holes 3 on the upper surface of the conductor is removed by belt sanding using # 400 belt abrasive paper (manufactured by Sankyo Rikagaku), and further, the scratches caused by the belt sanding are removed. The substrate surface was flattened by buffing to remove it (see FIG. 1 (e)).

(4) An electroless copper plating film 6 having a thickness of 0.6 μm is formed on the surface of the substrate flattened in the above (3) by applying a palladium colloid catalyst according to a conventional method and then performing electroless plating. (See FIG. 1 (f)).

(5) Next, electrolytic copper plating for thickening is performed under the following conditions to form an electrolytic copper plating film 7 having a thickness of 15 μm. A portion to become the through-hole-covered conductor layer 10 covering the conductive paste 5 filled in was formed. [Electroplating aqueous solution] Sulfuric acid 180 g / l Copper sulfate 80 g / l Additive (manufactured by Atotech Japan, trade name: Capparaside GL) 1 ml / l [Electroplating conditions] Current density 1 A / dm ² hours 30 minutes Temperature Room temperature

(6) A commercially available photosensitive dry film is adhered to both sides of the substrate on which the conductor circuit 9 and the portion to be the through-hole covered conductor layer 10 are formed, and a mask is placed thereon.
Exposure at mJ / cm ² and development processing with 0.8% sodium bicarbonate formed an etching resist 8 having a thickness of 15 μm (see FIG. 2 (a)).

(7) Then, the plating film in the portion where the etching resist 8 is not formed is dissolved and removed by etching using a mixed solution of sulfuric acid and hydrogen peroxide, and the plating resist 8 is peeled off with 5% KOH. The through-hole-covered conductor layer which is removed to cover the independent conductor circuit 9 and the conductive paste 5 filled in the through-hole (hereinafter, this through-hole covered conductor layer is simply referred to as a “lid plating layer”) 10
Was formed (see FIG. 2 (b)).

(8) Next, the conductor circuit 9 and the lid plating layer
A Ni thin film 11 having excellent adhesion to a polyolefin-based resin was formed on the entire surface including the side surfaces as well as the top surface of the thin film 10.
The Ni thin film 11 has an atmospheric pressure of 0.6 Pa, a temperature of 80 ° C., and an electric power of 20 Pa.
It was formed by sputtering with Ni as a target under the conditions of 0 W and a time of 5 minutes to form a Ni thin film layer having a thickness of 0.1 μm.

(9) Thereafter, a thermosetting polyolefin resin film 12 having a copper foil 30 adhered to one surface is overlaid on both surfaces of the substrate on which the Ni thin film 11 has been formed, and the temperature is 50-18.
By heating and pressing at a pressure of 10 kg / cm ² while raising the temperature to 0 ° C., the substrate, the film, and the copper foil are integrated to form a resin interlayer insulating layer 12 made of a polyolefin resin.
(See FIG. 2 (d)). The thermosetting polyolefin-based resin film 12 to which the copper foil 30 was adhered had a thickness of 12
A thermosetting polyolefin-based resin (manufactured by Sumitomo 3M, trade name: 1592) dissolved in NMP (N-methylpyrrolidone) is applied to a μm copper foil, dried at 50 ° C., and adjusted to a thickness of 50 μm. Manufactured.

(10) Prior to forming via holes for electrically connecting the copper foil 30 on the polyolefin-based resin interlayer insulating layer 12 and the lower conductive circuit after the above-described treatment, first, An opening is formed in the metal layer 30 made of by etching. Further, a via hole opening 13 having a diameter of about 80 μm was formed in the resin interlayer insulating layer 12 with a carbon dioxide gas laser having a wavelength of 10.4 μm (pulse time: 50 μsec). Further, desmear processing was performed by plasma processing of a mixed gas of CF ₄ and oxygen. Further, the entire surface of the interlayer resin insulation layer 12 including the metal layer 30 is sputtered with Ni as a target under the conditions of a pressure of 0.6 Pa, a temperature of 80 ° C., a power of 200 W, and a time of 5 minutes to obtain a polyolefin resin interlayer insulation 12. A Ni thin film was formed on the surface. At this time, the thickness of the formed Ni thin film was 0.1 μm.

(11) The substrate subjected to the above treatment was subjected to the electroless plating of (1) to form an electroless plated film 14 having a thickness of 0.7 μm (see FIG. 3A).

(12) In the above (11), the electroless plating film 14
A commercially available photosensitive dry film is attached to both sides of the substrate on which is formed, and a photomask film is placed on the substrate.
Exposure at J / cm ² and development using 0.8% sodium carbonate provided a 15 μm thick plating resist 16 (FIG. 3).
(b)).

(13) Thereafter, the electrolytic plating of (1) is further performed to form an electrolytic plated film 15 having a thickness of 15 μm.
The conductor circuit 9 was thickened and the via hole 17 was plated and filled (see FIG. 3 (c)).

(14) Further, after the plating resist 16 is peeled and removed with 5% KOH, the electroless plating film 14 under the plating resist 16 is dissolved and removed by etching with a mixed solution of sulfuric acid / hydrogen peroxide. 16 μm thick conductive circuit 9 composed of Ni film, electroless copper plating film 14 and electrolytic copper plating film 15
(Including via holes 17) was formed to produce a multilayer printed wiring board (see FIG. 3 (d)).

(Embodiment 2) FIGS. 4A to 4E show a part of a manufacturing process according to another embodiment. In this example, TPX (trade name) manufactured by Mitsui Chemicals was used as a polyolefin resin forming an interlayer resin insulating layer.
As shown in (a) to (c), after forming the electroless copper plating film 7 and before forming the etching resist 8, a Pd layer was formed by sputtering, and a via was formed in the resin interlayer insulating layer 12. After forming the hole opening 13, a multilayer printed wiring board was prepared in the same manner as in Example 1 except that sputtering was performed using Pd as a target instead of Ni to form a Pb film on the polyolefin-based resin interlayer insulation 12. Manufactured.

Comparative Example In this comparative example, a multilayer printed wiring board was manufactured in the same manner as in Example 1 except that a cresol novolak type epoxy resin was used instead of the polyolefin resin constituting the interlayer resin insulating layer. .

The above-described Examples 1, 2 and Comparative Examples were carried out based on the steps 1 to 3 described as one method for carrying out the production method of the present invention.

Example 3 (1) BT (Bizmaleimide Triazine) having a Thickness of 0.8 mm
A BT resin copper-clad laminate (manufactured by Mitsubishi Gas Chemical Co., Ltd.) in which 18 μm copper foils 2 are laminated on both sides of a resin substrate 1
Product name: HL830-0.8T12D) (see Fig. 1 (a)).
First, this copper-clad laminate is drilled (see FIG. 1 (b)), and then a palladium-tin colloid is adhered, and electroless plating is performed at a liquid temperature of 70 ° C. for 30 minutes with the following composition, and the entire surface of the substrate is 0.7 mm thick. A μm electroless plating film was formed. [Electroless plating aqueous solution] EDTA 150 g / l Copper sulfate 20 g / l HCHO 30 ml / l NaOH 40 g / l α, α'-bipyridyl 80 mg / l PEG 0.1 g / l

Further, electrolytic copper plating was performed with an aqueous electrolytic plating solution having the following composition under the following conditions to form an electrolytic copper plating film having a thickness of 15 μm (see FIG. 1 (c)). [Electroplating aqueous solution] Sulfuric acid 180 g / l Copper sulfate 80 g / l Additive (manufactured by Atotech Japan, trade name: Capparaside GL) 1 ml / l [Electroplating conditions] Current density 1 A / dm ² hours 30 minutes Temperature Room temperature

(2) A substrate having a conductor (including through-hole 3) formed of an electroless copper plating film and an electrolytic copper plating film formed on the entire surface is washed with water, dried, and then used as an oxidation bath (blackening bath). NaOH (10 g / l), NaClO ₂ (40 g / l), Na ₃ PO
₄ (6 g / l) aqueous solution and NaOH (1
0 g / l) and a redox treatment using an aqueous solution of NaBH ₄ (6 g / l) to provide a roughened layer 4 on the entire surface of the conductor circuit and the through-hole (see FIG. 1 (d)).

(3) Next, the conductive paste 5 containing copper particles was filled in the through holes 3 by screen printing, dried and cured. Then, the conductive paste 5 protruding from the roughened layer 4 and the through hole 3 on the upper surface of the conductor is # 400
Was removed by belt sanding using a belt polishing paper (manufactured by Sankyo Rikagaku Co., Ltd.), and buffing was performed to remove scratches due to the belt sanding, thereby flattening the substrate surface (see FIG. 1 (e)).

(4) An electroless copper plating film 6 having a thickness of 0.6 μm is formed on the surface of the substrate flattened in the above (3) by applying a palladium colloid catalyst according to a conventional method and then performing electroless plating. (See FIG. 1 (f)).

(5) Next, electrolytic copper plating is performed under the following conditions to form an electrolytic copper plating film 7 having a thickness of 15 μm. Through-hole-coated conductor layer 10 covering paste 5
Was formed. [Electroplating aqueous solution] Sulfuric acid 180 g / l Copper sulfate 80 g / l Additive (manufactured by Atotech Japan, trade name: Capparaside GL) 1 ml / l [Electroplating conditions] Current density 1 A / dm ² hours 30 minutes Temperature Room temperature

(6) A commercially available photosensitive dry film is attached to both sides of the substrate on which the portions to be the conductor circuits 9 and the conductor layers 10 are formed, a mask is placed, and exposure is performed at 100 mJ / cm ² .
The resist was developed with 0.8% sodium bicarbonate to form an etching resist 8 having a thickness of 15 μm (see FIG. 2A).

(7) Then, the plating film where the etching resist 8 is not formed is dissolved and removed by etching using a mixed solution of sulfuric acid and hydrogen peroxide, and the plating resist 8 is peeled off with 5% KOH. After removal, a through-hole-covered conductor layer (hereinafter, simply referred to as a “lid plating layer”) 10 covering the independent conductor circuit 9 and the conductive paste 5 was formed (FIG. 2 ( b)).

(8) Next, a 2.5 μm-thick roughened layer 11 made of a Cu—Ni—P alloy is formed on the surface of the conductive layer 10 covering the conductive circuit 9 and the conductive paste 5. 11
(See FIG. 2 (c), Sn is not shown). The formation method is as follows. That is, the substrate is acid-degreased and soft-etched, and then treated with a catalyst solution comprising palladium chloride and an organic acid to provide a Pd catalyst. After activating this catalyst, copper sulfate 8 g / l, nickel sulfate 0.6 g / l,
Electroless plating at pH = 9 consisting of an aqueous solution of 15 g / l of citric acid, 29 g / l of sodium hypophosphite, 31 g / l of boric acid, and 0.1 g / l of a surfactant (Sufinol 465, manufactured by Nissin Chemical Industry Co., Ltd.) Plating was performed in a bath, and a roughened layer 11 of a Cu—Ni—P alloy was provided on all surfaces of the conductor circuit 9 and the lid plating layer 10. Then, tin borofluoride 0.1 mol / l, thiourea 1.
Using a 0 mol / l aqueous solution, a Cu-Sn substitution reaction was carried out at a temperature of 50 ° C. and a pH of 1.2, and the thickness of the roughened layer 11 was
A 0.3 μm Sn layer was provided (the Sn layer is not shown).

(9) A copper foil with a polyolefin resin is applied to both surfaces of the substrate after the treatment of the above (8) at a pressure of 10 kg / cm.
^2. Pressure bonding and lamination at a temperature of 180 ° C. Thereafter, an opening of φ80 μm was provided by etching the copper foil. (10) Further, a 40 μm via hole opening 13 was formed in the polyolefin resin interlayer insulating layer by a carbon dioxide gas laser having a wavelength of 10.4 μm. Further, desmearing was performed by plasma treatment of a mixed gas of CF ₄ and oxygen. (11) Thereafter, sputtering using Pd as a target was performed under the conditions of a pressure of 0.6 Pa, a temperature of 80 ° C., a power of 200 W, and a time of 5 minutes to form a Pd thin film on the polyolefin resin interlayer insulating layer. At this time, the thickness of the formed thin film was 0.2 μm or less. The apparatus used for sputtering was manufactured by Japan Vacuum Engineering Co., Ltd.

(12) The substrate having been subjected to the treatment of (11) is subjected to the electroless plating of (1), and an electroless plating film 14 having a thickness of 0.7 μm is formed on the polyolefin resin interlayer insulating layer 12. (See FIG. 3 (a)).

(13) Further, electrolytic copper plating was performed under the condition (1) to form an electrolytic copper plating film 14 having a thickness of 15 μm. Then, a blackening treatment is applied to the upper surface of the copper plating, and thereafter,
An etching resist was formed, and a conductor circuit was formed by etching.

(14) Further, a copper foil with a polyolefin resin is applied to the treated conductor circuit forming substrate at a pressure of 10 kg / cm.
^{2. A} multilayer printed wiring board was manufactured by pressing and laminating at a temperature of 180 ° C. (see FIG. 3D).

Example 4 In this example, a multilayer printed wiring board was manufactured in the same manner as in Example 3 except that a metal Ni layer was formed by performing electroless Ni plating on the copper plating upper surface.

(Embodiment 5) In this embodiment, the upper surface of the copper plating is subjected to a sputtering process using Ni as a target.
A multilayer printed wiring board was manufactured in the same manner as in Example 3 except that a metal Ni layer was formed.

(Embodiment 6) In this embodiment, Au is applied at an atmospheric pressure of 0.6.
A multilayer printed wiring board was manufactured in the same manner as in Example 3 except that the film was adhered to the polyolefin-based resin interlayer insulating layer under the conditions of Pa, a temperature of 100 ° C., a power of 200 W, and a time of 1 minute.

(Embodiment 7) In this embodiment, a conductor circuit is provided by etching an electrolytic copper plating layer, and the surface of the conductor circuit is blackened, and then a polyolefin resin is applied to the roughened surface. A multilayer printed wiring board was manufactured in the same manner as in Example 3 except that the copper foil was heated and pressed.

(Embodiment 8) In this embodiment, a multilayer printed wiring board is manufactured in the same manner as in Embodiment 7, except that the surface of the formed conductor circuit is subjected to electroless Ni plating to form a metal Ni layer. Manufactured.

Example 9 In this example, a multilayer printed wiring board was manufactured in the same manner as in Example 7, except that the surface of the formed conductor circuit was roughened by an interplate treatment.

Example 10 Basically the same as Example 1, except that an 18 μm copper foil was etched with a sulfuric acid-hydrogen peroxide solution to a thickness of 5 μm. Further, a carbon dioxide laser (ML605GTL, manufactured by Mitsubishi Electric Corporation) was used for 54 μL.
Irradiation was performed with a pulse width of seconds to remove the copper foil and the polyolefin-based resin layer.

Examples 1 to 5 manufactured by the method as described above
The peel strength of the multilayer printed wiring boards according to Comparative Example 10 and Comparative Example was measured, and the resistance change rate after the wiring boards were left at 128 ° C. for 48 hours was measured. As a result, regarding the peel strength, the wiring boards according to Examples 1 to 10 are:
Despite not having a roughened surface on the interlayer resin insulation layer,
Although a sufficient peel strength of 0.8 to 1.0 kg / cm was obtained, the wiring board of the comparative example obtained only a low value of 0.1 kg / cm despite the provision of a roughened surface. In addition, as for the rate of change in resistance, it was confirmed that the wiring boards according to Examples 1 to 10 were relatively small at about 5%, while the wiring boards according to Comparative Examples were relatively large at 10%.

[0068]

As described above, according to the method for manufacturing a printed wiring board of the present invention, the signal propagation in a high frequency band is excellent without lowering the adhesion strength of the conductor circuit, and the connection of the via hole is achieved. A printed wiring board excellent in reliability can be provided.

[Brief description of the drawings]

FIGS. 1A to 1F are views showing a part of a process of manufacturing a multilayer printed wiring board of Example 1. FIG.

FIGS. 2A to 2E are diagrams illustrating a part of a process of manufacturing the multilayer printed wiring board according to the first embodiment.

3 (a) to 3 (d) are views each showing a part of a process of manufacturing the multilayer printed wiring board of Example 1. FIG.

FIGS. 4A to 4E are diagrams illustrating a part of a process of manufacturing a multilayer printed wiring board according to a second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Copper foil 3 Through hole 4 Roughening layer 5 Resin filler 6 Electroless plating film 7 Electrolytic plating film 8 Etching resist 9 Conductor circuit 10 Conductor layer (lid plating layer) 11 Metal layer (Ni, Pd) 12 Polyolefin type Resin insulating layer 13 Via hole opening 14 Electroless plating film 15 Electrolytic plating film 16 Plating resist 17 Via hole 30 Copper foil

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Motoo Asai 1-1 term north of Ibigawa-cho, Ibi-gun, Gifu F-term in Ibiden Co., Ltd. (reference) 5E343 AA07 AA13 AA15 AA16 AA17 AA18 BB23 BB24 BB35 BB38 BB44 BB45 BB48 BB55 BB67 CC01 CC22 CC78 DD33 DD43 DD52 DD76 EE32 EE42 GG01 5E346 AA02 AA06 AA12 AA15 AA43 CC08 CC31 CC37 CC38 DD02 DD22 DD33 DD47 EE02 EE06 EE07 EE19 EE33 EE38 FF03 FF13 FF14 GG15 H27 GG17 H22 GG17

Claims (4)

[Claims] 1. A resin film having a metal layer provided on one surface is heat-pressed to a substrate on which a conductive circuit is formed, an opening is formed in a part of the metal layer, and laser light is passed through the opening. Forming a hole for a via hole in the resin layer, and then forming a via hole and a conductive circuit to connect to a lower conductive circuit, wherein the resin film is a polyolefin. A method for producing a multilayer printed wiring board, wherein the method is a resin. 2. A resin film having a metal layer provided on one surface of a substrate on which a conductive circuit is formed is heated and pressed, and the metal layer is irradiated with laser light to form a via hole in the metal layer and the resin film. Forming a hole for formation, and then forming a via hole and a conductor circuit, and connecting to a lower layer conductor circuit in a method of manufacturing a multilayer printed wiring board, wherein the resin film is a polyolefin resin. A method for manufacturing a multilayer printed wiring board. 3. A method according to claim 1, wherein a roughening layer is provided on the upper surface of the conductor circuit formed on the substrate, or Ni, Pd, Cr, Co, P
3. The method for manufacturing a multilayer printed wiring board according to claim 1, wherein a metal layer made of at least one metal selected from t, Ti and Au is formed. 4. The entire surface of a conductor circuit formed on the substrate is roughened or Ni, Pd, Cr, Co, Pt, Ti
3. The method according to claim 1, wherein a metal layer made of at least one metal selected from the group consisting of Au and Au is formed.