JP2003264373A - Printed wiring board laminate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printed wiring board laminate which has excellent, adhesion, a wiring circuit profile and an excellent interline insulating characteristic even in a polymer substrate having a smooth surface when a high-density circuit is formed on the polymer substrate by using a semi-additive method, and also has an excellent dielectric characteristic, a low linear expansion property and a high glass transfer temperature. <P>SOLUTION: A laminate is provided with a metal layer on one surface of a polymer film and an adhesive layer on the other surface. In a printed wiring board laminate, in the whole structure body composed of the polymer film and an adhesion layer formed on one surface thereof, a relative dielectric constant is 3.5 or less, a dielectric tangent 0.02 or less, a thermal expansion coefficient 40 ppm or less and a glass transfer temperature 150°C or more. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminate for a printed wiring board, in which a metal layer is formed on a polymer film having a smooth flat surface and an adhesive layer is provided on the other surface thereof, and particularly to electrical laminates. The present invention relates to a laminate for a printed wiring board, which is widely used for electronic devices and is suitable for manufacturing a printed wiring board, and a printed wiring board using the same.

[0002]

2. Description of the Related Art A printed wiring board having a circuit formed on the surface of an insulating substrate is widely used for mounting electronic parts, semiconductor elements and the like. With the recent demand for miniaturization and high functionality of electronic devices, there is a strong demand for higher density and thinner circuits in printed wiring boards. In particular, establishment of a fine circuit forming method in which the distance between lines / spaces is 25 μm / 25 μm or less is an important issue in the field of printed wiring boards.

As a method for manufacturing this high-density printed wiring board, a method called a semi-additive method has been studied. As a typical example, a printed wiring board is manufactured by the following steps.

After roughening the surface of the insulating substrate and applying a plating catalyst such as a palladium compound, electroless copper plating is performed using the plating catalyst as a nucleus to form a thin metal film on the entire surface of the polymer film. To do.

Next, a resist film is applied or laminated on the surface of the electroless copper film, and the resist film on the portion where the circuit is to be formed is removed by a method such as photolithography. After that, electrolytic copper plating is performed using the exposed portion of the electroless plated film as a power supply electrode to form a second metal film on the portion where the circuit is formed. Next, after removing the resist coating, the exposed unnecessary electroless copper plating coating is removed by etching. At this time, the surface of the electrolytic copper plating film is also slightly etched to reduce the thickness and width of the circuit pattern.

Furthermore, if necessary, the surface of the formed circuit pattern is nickel-plated and gold-plated to manufacture a printed wiring board.

Since the semi-additive method is manufactured by etching a thin electroless copper film (first metal film), it is called a subtractive method in which a thick metal foil is etched to form a circuit. As compared with the method, it becomes possible to form a fine circuit with high accuracy.

[0008]

However, it has been clarified that this semi-additive method has the following problems.

The first is the problem of adhesion between the circuit pattern to be formed and the substrate. As described above, the electroless copper plating layer is provided between the substrate and the circuit pattern. Since the electroless plating layer is formed from the catalyst as an active site, it should be considered that the electroless plating layer has essentially no adhesion to the substrate. When the unevenness of the substrate surface is large, the adhesion during this period is kept good by the anchor effect, but naturally the adhesiveness tends to weaken as the substrate surface becomes smoother. Therefore, in the semi-additive method, a step of roughening the surface of the insulating substrate is required, and usually 10-point average roughness (Rz) has irregularities of about 3 to 5 μm. Such unevenness on the substrate surface has a line / space value of 30 to be formed.
If it is more than μm / 30 μm, there is no practical problem, but it is less than 30 μm / 30 μm, especially 25 μm / 25 μm.
There is a serious problem in forming a circuit having a line width of m or less. This is because such a high-density circuit line width is affected by the unevenness of the substrate surface.

Therefore, the line / space value is 25 μm.
In order to form a circuit of / 25 μm or less, a circuit forming technique on an insulating substrate having a smooth surface is required, and its planarity is preferably 1 μm or less, more preferably 0.5 μm or less in terms of Rz value. Of course, in this case, the adhesive strength due to the anchor effect becomes weaker, so it is necessary to develop another bonding method.

The second problem of the semi-additive method is its etching process. Since the electroless plating layer used as a power feeding layer for electroplating is an unnecessary layer in the circuit,
After the electroplating layer is formed, it needs to be removed by etching. However, when the electroless plated copper layer (first metal film) is removed by etching, the electroplated layer (second metal film) is removed.
Is also etched, the width and thickness of the circuit pattern are reduced,
It becomes difficult to manufacture a precise circuit pattern with good reproducibility. Especially when the surface roughness of the insulating substrate is large,
Since metal such as electroless plating remains in the concave and convex portions, it is necessary to take sufficient etching time to completely remove it. This means that the metal (second metal layer) that forms the circuit that should not be etched should be removed. Etching is performed more than necessary, resulting in a reduction in the width of the circuit pattern, deformation of the cross-sectional shape of the circuit, and in severe cases, disconnection of the circuit pattern.

A third problem is that since the plating catalyst is likely to remain on the surface of the polymer film, the insulation of the obtained printed wiring board is likely to deteriorate, and further nickel plating or gold plating is applied to the circuit in the final step. It is also possible that the surface of the polymer film is plated with nickel and gold due to the action of these remaining plating catalysts, and a circuit cannot be formed.

For this reason, the plating catalyst on the surface of the polymer film is also removed at the same time by removing the first metal film by etching using an etching solution having a high etching ability. However, when the electroless plating layer is removed by etching using this etching solution having a high etching ability, the circuit is excessively etched, and the same problem as described above occurs.

The fourth problem is the dielectric property of the resin material. With the increase of the semiconductor clock frequency, the wiring board material is required to have a small signal delay in the GHz band and a small transmission loss, that is, to have a low dielectric constant and a low dielectric loss tangent. . However, conventional materials such as epoxy resin have a relative dielectric constant of 3.5 to
The dielectric loss tangent is 4.0 and the dielectric loss tangent is about 0.03 to 0.05, and the advent of a new resin having a low dielectric constant and a low dielectric loss tangent is desired. A fifth problem is the thermal expansion property of the resin material. When a semiconductor having a very fine pad pitch of about 200 μm or less, such as flip-chip mounting, is mounted, the printed wiring board on which the semiconductor is mounted has good dimensional accuracy, that is, the coefficient of thermal expansion is It is required to be small and have a high glass transition temperature.

The present invention has been made to solve the above problems, and an object of the present invention is to provide an insulating substrate material capable of realizing a high-density printed wiring board. Is to provide a material for a printed wiring board which is capable of forming a high-density circuit having a line / space = 25 μm / 25 μm or less particularly in a circuit formation by a semi-additive method with a good cross-sectional shape of the circuit, and which has excellent dielectric characteristics and dimensional accuracy. It is in.

[0016]

DISCLOSURE OF THE INVENTION The present invention provides a polymer film having a metal layer on one surface and an adhesive layer on the other surface, and a polymer film and an adhesive formed on one surface thereof. It has been found that the above problems can be solved by paying attention to the characteristics of the entire layered structure.

That is, the first aspect of the present invention is to provide a polymer film in which a metal layer is provided on one surface of the polymer film and an adhesive layer is provided on the other surface of the polymer film, and the polymer film is obtained by removing only the metal layer from the laminate. The relative permittivity of the entire structure including the adhesive layer formed on one surface thereof is 3.5 or less, and the dielectric loss tangent is 0.02.
Below, thermal expansion coefficient 40ppm or less, glass transition temperature 15
It is a laminate for a printed wiring board, which has a temperature of 0 ° C or higher.

A second aspect of the present invention is the printed wiring board laminate of the first aspect, wherein the polymer film is a polyimide film. A third aspect of the present invention is a printed wiring board according to the first and second aspects of the present invention, in which the metal layer provided on one surface of the polymer film is formed by a physical method. It is a laminated body.

A fourth aspect of the present invention is the laminate for a printed wiring board according to the first to third aspects of the present invention, wherein the adhesive layer contains a polyimide resin.

A fifth aspect of the present invention is a printed wiring board using the first to fourth printed wiring board laminates of the present invention.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION A laminate for a printed wiring board according to the present invention will be described. First, as a method for forming the metal layer, a physical method such as a vacuum deposition method, an ion plating method, a sputtering method or a chemical method typified by electroless plating can be applied. In the present invention, the metal layer has a thickness of 2
It is 5 nm or more and 200 nm or less. To form a conductor layer with a thickness within this range uniformly, vacuum deposition, sputtering,
It is preferable to use a physical method such as ion plating. In particular, sputtering is preferred when comprehensively judging the facility, the productivity, and the adhesiveness between the obtained conductor layer and the polymer film.

Particularly, the case of using sputtering will be described in detail. A known method can be applied to the sputtering. That is, DC magnetron sputtering, RF sputtering, or those obtained by making various improvements to these methods can be appropriately applied according to the respective requirements. For example, DC magnetron sputtering is preferable in order to efficiently sputter conductors such as nickel and copper. On the other hand, RF sputtering is suitable for sputtering in a high vacuum for the purpose of preventing sputter gas from entering the thin film. The DC magnetron sputtering will be described in detail. First, a polymer film as a substrate is set in a vacuum chamber and a vacuum is drawn. Usually, roughing by a rotary pump is combined with a diffusion pump, a cryopump, or a turbo pump, and a vacuum is usually pulled up to 6 × 10 ⁻⁴ Pa or less. Next, sputter gas is introduced to make the inside of the chamber 0.1 Pa to 10 Pa.
Pa is preferably 0.1 Pa to 1 Pa, and a DC voltage is applied to the metal target to cause plasma discharge. At this time, by forming a magnetic field on the target and confining the generated plasma in the magnetic field, the sputtering efficiency of plasma particles to the target is increased. While avoiding the influence of plasma or sputtering on the polymer film, the surface oxide layer of the metal target is removed by maintaining the plasma for several minutes to several hours (referred to as pre-sputtering). After the pre-sputtering is completed, the polymer film is sputtered by opening the shutter. The discharge power during sputtering is preferably in the range of 100W to 1000W. In addition, batch-type sputtering or roll sputtering is applied according to the shape of the sample to be sputtered. An inert gas such as argon is usually used as the introduced sputtering gas, but a mixed gas containing a small amount of oxygen or another gas can also be used.

Further, in order to improve the adhesion between the polymer film and the sputtered film, plasma discharge treatment as pretreatment,
Corona discharge treatment, heat treatment, ion bombardment treatment, etc. can be applied. Usually, if the polymer film is exposed to the atmosphere after these treatments, the modified surface may be inactivated and the treatment effect may be greatly reduced. It is preferable to continuously sputter.

Further, by using a metal layer composed of two kinds of metals, etching characteristics, adhesiveness with a polymer film,
The peel strength from the electroless plating or electroplating film can be improved. As the metal having a high peeling strength from the polymer film, nickel, chromium, tin, titanium, aluminum or the like is used. In addition, it is common to use copper, which has a high electric conductivity, for the circuit pattern. Therefore, first forming a metal layer of nickel or the like on the polymer film and then copper is effective to improve the peeling strength of nickel with the subsequent electroless copper plating or electrolytic copper plating.

In this case, the thickness of nickel is 2 nm or more and 5
It is preferably 0 nm or less, more preferably 10 nm or more and 50 nm or less. If it is thinner than this, it becomes difficult to form a uniform film on the polymer film. If it is thicker than this, there is a problem that the film peels off or curls due to the stress in the film between the second metal layer and copper and the difference in dimensional change due to temperature. The thickness of copper of the second metal layer is 10 nm or more and 200 nm
Hereafter, it is preferably 50 nm or more and 100 nm or less. If it is thinner than this, the effect of improving the peeling strength is insufficient. On the other hand, if it is thicker than this range, it is not preferable for the etching characteristics in semi-additive. On the other hand, if the total thickness of these metals is thicker than 200 nm, the etching property deteriorates and it is unsuitable for forming a high-density circuit pattern. Even when two or more kinds of metal layers are laminated and formed, if an oxide layer is formed on the surface of each sputtered film, the adhesion between the respective metals will be deteriorated. Therefore, it is preferable to carry out the sputtering continuously in a vacuum.

Next, the polymer film will be described. The polymer film used in the present invention has a surface 10-point average roughness (referred to as Rz) of 1 μm or less, preferably 0.5 μm or less. The smooth surface is suitable for forming a high-density circuit having a line / space of 25 μm / 25 μm or less, and is also preferable in that unevenness on the resin surface does not cause an etching residue in the etching step. Rz is stipulated in a standard relating to the surface shape such as JIS B0601, and its measurement is performed according to JIS B065.
The stylus type surface roughness meter of No. 1 and the light wave interference type surface roughness meter of B0652 can be used. In the present invention, the 10-point average roughness of the polymer film was measured using a light wave interference type surface roughness meter NewView 5030 system manufactured by ZYGO.

The dielectric constant of the polymer film is preferably 3.5 or less, preferably 3.2 or less, more preferably 3.0 or less, and the dielectric loss tangent is 0.02 or less, preferably 0.015. It is preferably below 0.01, more preferably below 0.01. This means that the transmission signal becomes higher in frequency,
It is required from the viewpoint of speeding up and reduction of transmission loss. The dielectric characteristics have frequency dependence, and the present invention has a problem of dielectric constant and dielectric loss tangent in a high frequency band from MHz band to GHz band. Various methods have been proposed as measurement methods, but the cavity resonator method is superior in terms of measurement stability and reproducibility. In the present invention, a cavity resonator type MOA 2012 is used.
Measurement frequency 12.5GH using (made by KS Systems)
It was measured by z.

The coefficient of thermal expansion of the polymer film is 2
It is preferably 0 ppm or less, preferably 15 ppm or less, more preferably 13 ppm or less. The thickness of the polymer film is preferably 5 μm or more and 125 μm or less, more preferably 10 μm or more and 50 μm or less, and most preferably 10 μm or more and 25 μm or less. When the thickness is smaller than this range, the rigidity of the laminate is insufficient, the handleability is deteriorated, and the electric insulation between the layers is deteriorated. On the other hand, if the film is too thick, it not only goes against the trend of thinner printed wiring boards, but also when controlling the characteristic impedance of the circuit.
If the insulating layer becomes thicker, it is necessary to widen the circuit width,
This is unacceptable due to the demand for miniaturization and high density of printed wiring boards.

The polymer film used in the present invention is not particularly limited as long as it has the above-mentioned characteristics, and examples thereof include epoxy resin type, phenol resin type, polyamide resin type, polyimide resin type and unsaturated polyester resin. A thermosetting resin such as a resin, a polyphenylene ether resin system, or polyphenylene sulfide can be used. From the viewpoint of heat resistance, chemical resistance, electrical characteristics, processability, etc., polyimide resin type, epoxy resin type, etc. are preferable, and polyimide film is most preferable. The inside of this polymer film may have a conductor circuit, a through hole, or the like. Roughening treatment on the surface of the polymer film in order to improve the peel strength from the first metal coating, corona discharge treatment, plasma treatment, flame treatment, heat treatment, various known surfaces such as primer treatment. You may give a process. Also,
It is also effective and preferable to add a known adhesiveness-imparting agent or surface-treat it to the resin constituting the polymer film. Among these, from the viewpoints of heat resistance, flexibility, dimensional stability, dielectric constant, price, etc., a polyimide resin type, an epoxy resin type, or a blend of these is preferable.

The case where a polyimide film is used as the polymer film will be described in detail below. A known manufacturing method can be applied to the polyimide film. That is,
A polyamic acid polymer solution obtained by polymerizing in an organic polar solvent, using one or more tetracarboxylic dianhydride components and one or more diamine components in substantially equimolar amounts Casting coating on a support such as a glass plate or a stainless belt, and peeling a partially imidized or partially dried polyamic acid film (hereinafter referred to as gel film) to the extent that it has self-supporting properties is peeled off from the support, It can be obtained by fixing the end portion with a method such as a pin or a clip and further heating to completely imidize the polyamic acid.

Known tetracarboxylic dianhydrides can be used as the tetracarboxylic dianhydride component used in the production of the polyamic acid polymer. Specifically, pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, 3,3 ′,
4,4'-diphenylsulfone tetracarboxylic acid dianhydride, 1,4,5,8-naphthalene tetracarboxylic acid dianhydride, 2,3,6,7-naphthalene tetracarboxylic acid dianhydride, 4,4 ' -Oxydiphthalic anhydride, 3,
3 ', 4,4'-dimethyldiphenylsilanetetracarboxylic dianhydride, 3,3', 4,4'-tetraphenylsilanetetracarboxylic dianhydride, 1,2,3,4-furantetracarboxylic acid Dianhydride, 4,4'-bis (3,3
4-dicarboxyphenoxy) diphenylpropane dianhydride, 4,4'-hexafluoroisopropylidene diphthalic anhydride, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, 2,3,3 Examples include aromatic tetracarboxylic dianhydrides such as', 4'-biphenyltetracarboxylic dianhydride and p-phenylenediphthalic anhydride.

In order to obtain a polyimide film suitable for use in the present invention, p-phenylene bis (trimellitic acid monoester anhydride) (hereinafter referred to as TMHQ) and pyromellitic dianhydride (hereinafter referred to as PMDA) are used. It is preferable to mix them in an arbitrary ratio.

On the other hand, known diamines can be used as typical diamine components used for producing the polyamic acid polymer. Specifically, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 2,2-bis (4-aminophenoxyphenyl) propane, 1,4-bis (4-aminophenoxy)
Benzene, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, bis (4- (4-aminophenoxy) phenyl) sulfone, bis (4- (3-amino) Phenoxy) phenyl) sulfone, 4,4'-bis (4-aminophenoxy) biphenyl, 2,2-bis (4-aminophenoxyphenyl) hexafluoropropane, 4,4'-diaminodiphenyl sulfone, 3,3'- Diaminodiphenylsulfone, 9,9-bis (4-aminophenyl) fluorene, bisaminophenoxyketone, 4,4'-
(1,4-phenylenebis (1-methylethylidene))
Bisaniline, 4,4 '-(1,3-phenylenebis (1-methylethylidene)) bisaniline, m-phenylenediamine, p-phenylenediamine, 4,4'-diaminobenzanilide, 3,3'-dimethyl-4 4 '
-Diaminobiphenyl, 3,3'-dimethoxy-4,
Examples include aromatic diamines such as 4'-diaminobiphenyl, 3,3'-dimethylbenzidine, and 3,3'-dihydroxybenzidine, and other aliphatic diamines.

In order to obtain a polyimide film suitable for the use of the present invention, paraphenylenediamine (hereinafter referred to as PD
A) 4,4'-diaminobenzanilide (hereinafter,
A mixture of DABA) and 4,4′-diaminodiphenyl ether (hereinafter referred to as ODA) in an arbitrary ratio is preferable.

The combination of the tetracarboxylic dianhydride component and the diamine component described here is one specific example for obtaining the polyimide film of the present invention, and not limited to these combinations, the tetracarboxylic acid used It is possible to adjust the characteristics of the polyimide film by changing the combination and the use ratio of the dianhydride component and the diamine component.

Examples of the organic polar solvent used in the reaction for producing the polyamic acid copolymer include sulfoxide solvents such as dimethyl sulfoxide and diethyl sulfoxide, and formamide such as N, N-dimethylformamide and N, N-diethylformamide. System solvents, acetamide-based solvents such as N, N-dimethylacetamide, N, N-diethylacetamide, N-methyl-2-pyrrolidone,
A pyrrolidone-based solvent such as N-vinyl-2-pyrrolidone,
Phenol-based solvents such as phenol, o-, m- or p-cresol, xylenol, halogenated phenol and catechol, hexamethylphosphoramide and γ-butyrolactone can be used, and these are used alone or as a mixture. However, it is also possible to partially use an aromatic hydrocarbon such as xylene or toluene.

Known methods can be applied to prepare a polyamic acid polymer solution using these raw materials. Specifically, a method of gradually adding a tetracarboxylic dianhydride component after dissolving a diamine component in a solvent, a method of simultaneously dissolving a diamine component and a tetracarboxylic dianhydride component in a solvent, a diamine component and a tetracarboxylic acid Examples include a method of alternately dissolving the acid dianhydride component and the like.

When a polyamic acid polymer solution is copolymerized using three or more kinds of monomer raw materials, it is possible to control the order of addition of each raw material to control the arrangement of molecules in the polymer. Methods such as random copolymerization, block copolymerization, partial block copolymerization and sequential copolymerization have been proposed. The average molecular weight of the polyamic acid that is the precursor of the polyimide film of the present invention is 1
It is desirable that it is from 10,000 to 1,000,000. If the average molecular weight is less than 10,000, the resulting film may become brittle. On the other hand, 1,000,00
If it exceeds 0, the viscosity of the polyamic acid varnish, which is a polyimide precursor, becomes too high, which may make the handling difficult.

In the polymerization of the polyamic acid polymer solution, a step such as filtration may be performed at any stage before, during or after the polymerization for the purpose of removing foreign matters and high molecular weight substances in the polyamic acid polymer solution. It is also possible to add.

Further, in order to shorten the time required for the polymerization step, a first polymerization step for obtaining a so-called prepolymer having a low polymerization degree and a second polymerization step for further increasing the polymerization degree to obtain a high molecular weight polyamic acid polymer solution It is also possible to separate the polymerization steps. In particular, it is preferable from the viewpoint of polymerization efficiency and filtration efficiency to perform the second polymerization step after passing through the steps such as filtration in the prepolymer stage after the first polymerization step.

The polyamic acid copolymer is contained in the above organic polar solvent in an amount of 5 to 40% by weight, preferably 10 to 40% by weight.
It is desirable that it is dissolved in 30% by weight from the viewpoint of handling.

As a method for molding the polyamic acid polymer solution obtained by the above method into a polyimide film, a known method can be applied. That is, a polyamic acid film obtained by casting and coating a polyamic acid polymer solution on a support such as glass or stainless steel and partially imidizing or partially drying it to the extent that it has self-supporting property (hereinafter referred to as gel film) Is peeled off from the support, the end is fixed by a method such as a pin or clip, and further heated to completely imidize the polyamic acid. At this time, a curing agent (hereinafter referred to as a chemical curing agent) in which a dehydrating agent and a catalyst which accelerate the imidization reaction of the polyamic acid and a solvent are mixed before the polyamic acid is applied by casting, is added to the polyamic acid solution, and mixed, A so-called chemical curing method of stirring, a thermal curing method of thermally imidizing, a method of using both in combination, and the like can be applied.

From the viewpoint of the productivity of the film and the physical properties of the obtained film, the chemical cure method or the combined use of the chemical cure method and the heat cure method is preferable. Further, the polyimide film obtained by the above method may be subjected to known surface treatment or post-treatment. Specifically, corona discharge treatment, plasma discharge treatment, electron beam irradiation treatment, UV treatment,
Heat treatment, flame treatment, solvent cleaning treatment, primer treatment,
Chemical etching treatment or the like can be applied. Further, it is also possible to obtain a polyimide film after treating the gel film alone or in combination of a plurality of treatments. In particular, a partially imidized or partially dried polyamic acid film (gel film)
Are Al, Si, Ti, Mn, Fe, Co, Cu, Zn,
Method of completely drying and imidizing polyamic acid after dipping in a solution of a compound containing at least one element selected from the group consisting of Sn, Sb, Pb, Bi and Pd or applying the solution to the gel film Is effective in improving the adhesiveness.

The gel film is in the middle of drying and contains a solvent. This solvent content (volatile component content) is calculated from Equation 1.

(A−B) × 100 / B ... Formula 1 In Formula 1, A and B represent the following. A is the weight B of the gel film, and the weight volatile component content after heating the gel film at 450 ° C. for 20 minutes is in the range of 5 to 300% by weight, preferably 5 to 100% by weight, more preferably 5-50
A weight% range is preferred. The gel film is in the middle of the reaction from the polyamic acid to the polyimide, and the imidization ratio showing the progress of the reaction is calculated from the formula 2 by using the infrared absorption spectrometry.

(C / D) × 100 / (E / F) ... Equation 2 In Equation 2, C, D, E, and F represent the following. C: absorption peak height of gel film at 1370 cm ^-1 D: absorption peak height of gel film at 1500 cm ^-1 E: absorption peak height of polyimide film at 1370 cm ^-1 F: absorption peak of polyimide film at 1500 cm ^-1 High imidization ratio is in the range of 50% or more, preferably 70% or more, more preferably 80% or more, and most preferably 85%.
The above range is preferable. Al, Si, Ti, Mn, F
e, Co, Cu, Zn, Sn, Sb, Pb, Bi, Pd
As the compound containing at least one element selected from the group consisting of, those in the form of organic or inorganic compounds containing the above elements are preferably used.

Specifically, examples of the inorganic compound include halides such as chlorides and bromides, oxides, hydroxides,
Examples thereof include carbonates, nitrates, nitrites, phosphates, sulfates, silicates, borates and condensed phosphates.

Examples of the organic compound include neutral compounds such as alkoxides, acylates, chelates, diamines and diphosphines, organic compounds having acetylacetonate ion, carboxylate ion, dithiocarbamate ion and the like, and cyclic compounds such as porphyrin. Examples include ligands. Among these, preferable elements are Si and Ti.
The compound containing these elements is provided in the form of alkoxide, acylate, chelate, or metal salt.

For silicon compounds, N-β (aminoethyl)
Aminosilane compounds such as γ-aminopropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropylmethyldimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane and γ-aminopropyltriethoxysilane, Examples thereof include epoxysilane compounds such as β- (3,4 epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-glycidoxypropylmethyldimethoxysilane.

The titanium compound is preferably represented by the general formula (Formula 1), and specifically, tri-n-butoxytitanium monostearate, diisopropoxytitanium bis (triethanolaminate), butyl titanate dimer,
Examples include tetra-normal butyl titanate, tetra (2-ethylhexyl) titanate, titanium octylene glycolate, and the like, as well as dihydroxybis (ammonium lactate) titanium, dihydroxytitanium bislactate, and the like. Most preferred is tri-n
-Butoxy titanium monostearate or dihydroxy titanium bis-lactate.

[0051]

[Chemical 1] The solvent used in the solution may be one that dissolves the above compound. For example, water, toluene, xylene,
Tetrahydrofuran, 2-propanol, 1-butanol, ethyl acetate, N, N-dimethylformamide, acetylacetone and the like can be used. Two or more kinds of these solvents may be mixed and used, and it is also possible to mix a chemical curing agent component of polyamic acid. In the present invention, N, N-dimethylformamide, 1-butanol, 2-propanol and water can be particularly preferably used.

The concentration of the solution is preferably 0.01% to 1
0% is preferable, and 0.1% to 5% is more preferable.
That is, the concentration of the element in the solution is 1 ppm to 100,0
00 ppm is preferable and 10 ppm to 50,000 pp
m is more preferred. It is preferable to apply a step of removing the extra droplets on the surface after applying or immersing the solution on the gel film, because a polyimide film having an excellent appearance without unevenness on the film surface can be obtained. A known method such as a nip roll, an air knife, or a doctor blade can be used to remove the droplets, and the nip roll can be preferably used from the viewpoint of the appearance of the film, the drainage property, the workability, and the like. It is also possible to add various organic additives, inorganic fillers, or various reinforcing materials at any stage of producing the polyimide film to obtain a composite polyimide film.

The thickness of the polyimide film in the present invention is not limited, but is preferably 5 μm to 125 μm. In particular, for use as a multilayer printed wiring board, the thickness of the polyimide film is 10 to 75 μm, preferably 10 to 50 μm, the tensile elastic modulus is 4 GPa or more, preferably 6 GPa or more, more preferably 10 GPa or more, and the linear expansion coefficient is 17 ppm.
Or less, preferably 12 ppm or less, more preferably 10 ppm or less.
It is preferably ppm or less and water absorption of 2% or less, preferably 1.5% or less, more preferably 1% or less.

The laminate for a printed wiring board according to the present invention is used for a printed wiring board. Therefore, the laminate for a printed wiring board is subjected to electroless plating and electroplating. However, since these processes use various chemical treatments such as strong acids and strong alkalis that cause a considerable damage to the insulating resin, it is practically important to secure the peeling strength of these circuit patterns. A known electroless plating treatment can be applied as the electroless copper plating step. Usually, the steps of roughening the substrate surface, cleaning the substrate surface, pre-dip, applying a plating catalyst, activating the plating catalyst, and forming an electroless plating film are performed. Normally 0.2-0.3μ
Depending on the m and the conditions, a plating film of 0.8 to 1 μm can be formed.

A known method can be applied to the electroplating. Specifically, copper sulfate plating, copper bromide plating, copper pyrophosphate plating and the like are known, but copper sulfate plating is preferable from the viewpoint of handling of the plating solution, productivity, film characteristics and the like. The plating solution composition and plating conditions for copper sulfate plating are exemplified in Table 1.

[0056]

[Table 1] For the peeling strength of the conductor layer, after electroless plating on the metal layer, electroplating is performed on the entire surface by copper sulfate plating without forming a resist pattern under the condition of 2 A / dm2 for 40 minutes to form a copper plating layer having a thickness of 20 μm. JIS C6471
Based on (Peeling strength: Method B), the peeling strength between the polymer film and the conductor layer was measured at a measurement pattern width of 3 mm, a crosshead speed of 50 mm / min, and a peeling angle of 180 degrees.

The thickness of the adhesive layer used in the laminate according to the present invention is 5 μm or more and 125 μm or less, preferably 5 μm or more and 50 μm or less. The adhesive layer needs to have a sufficient amount and thickness to embed the inner layer circuit pattern at the time of stacking. Although it depends on the pattern ratio of the inner layer circuit, the thickness is usually required to be about 1/2 to 1 times the inner layer circuit thickness. That is, assuming that the practically effective minimum circuit thickness is about 9 μm, assuming that the pattern ratio is 50%, the minimum thickness of the adhesive layer is about 5 μm. On the other hand, if the adhesive layer is too thick, not only goes against the demand for thinner and smaller printed wiring boards, as in the case of polymer films, but also the adhesive flows out from the substrate during the laminating process, and This causes problems such as contaminating the processing equipment and remaining volatile components such as a solvent in the adhesive, causing foaming and other causes.

The adhesive layer is not particularly limited in type, and a known resin applicable to the adhesive can be applied. It can be roughly classified into (A) a heat-fusible adhesive that uses a thermoplastic resin, and (B) a curable adhesive that uses the curing reaction of a thermosetting resin. These will be described below.

Examples of the thermoplastic resin (A) which gives the adhesive a heat-sealing property include polyimide resin, polyamideimide resin, polyetherimide resin, polyamide resin, polyester resin, polycarbonate resin, polyketone resin, polysulfone resin, Examples thereof include polyphenylene ether resin, polyolefin resin, polyphenylene sulfide resin, fluororesin, polyarylate resin, liquid crystal polymer resin, etc., and one or more of these may be used in combination as an adhesive layer of the laminate of the present invention. You can Above all, it is preferable to use a thermoplastic polyimide resin from the viewpoint of excellent heat resistance, electrical reliability, and the like.

Here, a method for producing the thermoplastic polyimide resin will be described. The polyimide resin is obtained from a polyamic acid polymer solution which is a precursor thereof, and the polyamic acid polymer solution can be produced by a known method as described above. That is, it is obtained by using tetracarboxylic dianhydride component and diamine component in substantially equimolar amounts and polymerizing in an organic polar solvent. The acid dianhydride used in this thermoplastic polyimide resin is not particularly limited as long as it is an acid dianhydride. Examples of the acid dianhydride component include butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,
3,4-cyclobutanetetracarboxylic acid, 1,2,3
4-cyclopentanetetracarboxylic dianhydride, 2,
3,5-tricarboxycyclopentyl acetic acid dianhydride,
3,5,6-Tricarboxynorbonane-2-acetic acid dianhydride, 2,3,4,5-tetrahydrofuran tetracarboxylic acid dianhydride, 5- (2,5-dioxotetrahydrofural) -3-methyl -3-Cyclohexene-1,2-
Aliphatic or alicyclic tetracarboxylic dianhydrides such as dicarboxylic dianhydrides, bicyclo [2,2,2] -oct-7-ene-2,3,5,6-tetracarboxylic dianhydrides; Pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 3,3 ′,
4,4'-diphenylsulfone tetracarboxylic acid dianhydride, 1,4,5,8-naphthalene tetracarboxylic acid dianhydride, 2,3,6,7-naphthalene tetracarboxylic acid dianhydride, 4,4 ' -Oxyphthalic anhydride, 3,3 ',
4,4'-dimethyldiphenylsilanetetracarboxylic dianhydride, 3,3 ', 4,4'-tetraphenylsilanetetracarboxylic dianhydride, 1,2,3,4-furantetracarboxylic dianhydride 4,4'-bis (3,4-dicarboxyphenoxy) diphenyl sulfide dianhydride, 4,4'-bis (3,4-dicarboxyphenoxy) diphenyl sulfone dianhydride, 4,4'-bis ( 3,4-dicarboxyphenoxy) diphenylpropane dianhydride, 4,4'-hexafluoroisopropylidene diphthalic anhydride, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, 2,3 , 3 ', 4'-biphenyltetracarboxylic dianhydride, bis (phthalic acid) phenylphosphine oxide dianhydride, p-phenylene-bis (triphenylphthalic acid) dianhydride m- phenylene - bis (triphenyl phthalic acid) dianhydride, bis (triphenyl phthalic acid) -4,4'-diphenyl ether dianhydride, bis (triphenyl phthalic acid) -4,
Aromatic tetracarboxylic dianhydrides such as 4'-diphenylmethane dianhydride, 2,2-bis (4-hydroxyphenyl) propanedibenzoate-3,3 ', 4,4'-tetracarboxylic dianhydride, p-phenylene bis (trimellitic acid monoester anhydride), 4,4'-biphenylene bis (trimellitic acid monoester anhydride), 1,4
-Naphthalene bis (trimellitic acid monoester anhydride), 1,2-ethylene bis (trimellitic acid monoester anhydride), 1,3-trimethylene bis (trimellitic acid monoester anhydride), 1,4- Tetramethylene bis (trimellitic acid monoester anhydride), 1,5-pentamethylene bis (trimellitic acid monoester anhydride), 1,6-hexamethylene bis (trimellitic acid monoester anhydride), 4,4 '-(4,4'-isopropylidenediphenoxy) bis (phthalic anhydride) and the like are preferable, and it is possible to use one of these or a combination of two or more thereof as a part or all of the acid dianhydride component. it can. 2,2-bis (4-hydroxyphenyl) propanedibenzoate-3,3 ′, 4,4′-tetracarboxylic dianhydride, for exhibiting excellent heat-sealing property,
1,2-ethylenebis (trimellitic acid monoester anhydride), 4,4'-hexafluoroisopropylidene diphthalic anhydride, 2,3,3 ', 4'-biphenyltetracarboxylic dianhydride, 4 , 4'-oxydiphthalic anhydride, 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride, 4,4'-(4,4'-isopropylidenediphenoxy) bis (phthalic anhydride) It is preferably used. As the diamine component, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2, -bis [3- ( 3-
Aminophenoxy) phenyl] propane, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4
-Aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, bis (4- (4-aminophenoxy) phenyl) sulfone, bis (4- (3-aminophenoxy) phenyl) sulfone, 4,4 '-Bis (4-aminophenoxy) biphenyl, 2,2-bis (4-aminophenoxyphenyl) hexafluoropropane, 4,4'-diaminodiphenylsulfone, 3,
3'-diaminodiphenylsulfone, 9,9-bis (4-aminophenyl) fluorene, bisaminophenoxyketone, 4,4 '-(1,4-phenylenebis (1
-Methylethylidene)) bisaniline, 4,4'-
(1,3-phenylenebis (1-methylethylidene))
Bisaniline, 3,3'-dimethylbenzidine, 3,
3′-dihydroxybenzidine and the like,
These may be used alone or in combination of two or more.

Materials for the thermoplastic polyimide resin used in the laminate of the present invention include 1,3-bis (3-aminophenoxy) benzene, 3,3'-dihydroxybenzidine and bis (4- (3-aminophenoxy)). It is preferable to use each of the phenyl) sulfones alone or in a mixture at an arbitrary ratio.

As a typical procedure for the reaction to obtain a polyamic acid polymer solution, one or more diamine components are dissolved or diffused in an organic polar solvent, and then one or more acid dianhydride components are added to the polyamic acid solution. The method of obtaining. The order of addition of each monomer is not particularly limited, and the acid dianhydride component may be added in advance to the organic polar solvent, the diamine component may be added, and the solution of the polyamic acid polymer may be used,
The diamine component may be first added to the organic polar solvent in an appropriate amount, then the excess acid dianhydride component may be added, and the diamine component corresponding to the excess amount may be added to obtain a solution of the polyamic acid polymer. Besides this, there are various addition methods known to those skilled in the art. The term "dissolved" as used herein refers to a state in which the solute is substantially dissolved by being uniformly dispersed or dispersed in the solvent, in addition to the case where the solvent completely dissolves the solute. Including cases.

Examples of the organic polar solvent used in the reaction for producing the polyamic acid solution include sulfoxide solvents such as dimethyl sulfoxide and diethyl sulfoxide,
Formamide solvents such as N, N-dimethylformamide and N, N-diethylformamide, acetamide solvents such as N, N-dimethylacetamide and N, N-diethylacetamide, N-methyl-2-pyrrolidone and N-vinyl- Pyrrolidone-based solvent such as 2-pyrrolidone, phenol-based solvent such as phenol, o-, m- or p-cresol, xylenol, halogenated phenol and catechol, or hexamethylphosphoramide, γ-
Butyrolactone and the like can be mentioned. Furthermore, if necessary, these organic polar solvents may be used in combination with an aromatic hydrocarbon such as xylene or toluene. Next, a method of imidizing a polyamic acid will be described.

The imidization reaction of polyamic acid is a dehydration ring closure reaction of polyamic acid, and water is produced by the reaction.
The generated water easily hydrolyzes the polyamic acid and causes a decrease in the molecular weight. As a method for imidizing while removing this water, usually 1) a method in which an azeotropic solvent such as toluene / xylene is added to remove it azeotropically, 2) an aliphatic acid dianhydride such as acetic anhydride and triethylamine / pyridine / picoline -Chemical imidization method in which a tertiary amine such as isoquinoline is added, and 3) there is a method of heating under reduced pressure for imidization.

The method of imidizing the thermoplastic polyimide resin of the present invention is preferably a method of heating under a reduced pressure to imidize. According to this imidization method, water generated by imidization can be positively removed to the outside of the system, so that hydrolysis of polyamic acid can be suppressed and a high molecular weight polyimide can be obtained. Further, according to this method, the ring-opened product on one side or both sides present as an impurity in the acid dianhydride as the raw material is re-closed, so that a further improvement effect of the molecular weight can be expected.

The heating condition of the method of heating and imidizing under reduced pressure is preferably 80 to 400 ° C., more preferably 100 ° C. or higher, and more preferably 120 ° C., which enables efficient imidization and efficient removal of water. That is all. The maximum temperature is preferably equal to or lower than the thermal decomposition temperature of the intended polyimide, and the normal imidization completion temperature, that is, 250 to 350.
℃ degree is usually applied.

The condition of the pressure for reducing the pressure is preferably as small as possible, but specifically, it is 900 hPa or less, preferably 80 hPa.
It is 0 hPa or less, more preferably 700 hPa or less. Further, as another method for obtaining the thermoplastic polyimide resin, there is a method in which the solvent is not evaporated in the above-mentioned method of thermally or chemically dehydrating and ring-closing. Specifically, a polyimide resin solution obtained by performing a chemical imidization treatment with a thermal imidization treatment or a dehydrating agent is put into a poor solvent, the polyimide resin is precipitated, and unreacted monomers are removed and purified, It is a method of obtaining a solid polyimide resin by drying. As the poor solvent, polyimide that is mixed well with a solvent but has a property that the polyimide is difficult to dissolve is selected, and, for example, acetone, methanol, ethanol, isopropanol, benzene, methyl cellosolve,
Examples thereof include, but are not limited to, methyl ethyl ketone. A thermoplastic polyimide resin can be obtained by these methods and can be used as an adhesive layer of the laminate of the present invention.

Next, (B) a curable adhesive utilizing the curing reaction of the thermosetting resin will be described. As the thermosetting resin, bismaleimide resin, bisallylnadiimide resin,
Phenol resin, cyanate resin, epoxy resin, acrylic resin, methacrylic resin, triazine resin, hydrosilyl cured resin, allyl cured resin, unsaturated polyester resin and the like can be mentioned, and these can be used alone or in an appropriate combination. In addition to the thermosetting resin, an epoxy group, an allyl group, a vinyl group, an alkoxysilyl group, a hydrosilyl group at the side chain or terminal of the polymer chain,
It is also possible to use a side chain reactive group type thermosetting polymer having a reactive group such as a hydroxyl group as a thermosetting component.

The side chain reactive group type thermosetting polyimide resin will be described below. As an example of a specific manufacturing method, (1)
Manufactured by a method similar to that of the thermoplastic polyimide resin already described, in which case epoxy group, vinyl group, allyl group, methacryl group, acryl group, alkoxysilyl group, hydrosilyl group, carboxy group, hydroxyl group, cyano group, etc. A method for obtaining a thermosetting polyimide by using a diamine component having a group and an acid dianhydride component as a monomer component, and (2) a thermoplastic polyimide having already described a solvent-soluble polyimide having a hydroxyl group, a carboxy group, an aromatic halogen group, etc. A method in which functional groups such as an epoxy group, a vinyl group, an allyl group, a methacrylic group, an acryl group, an alkoxysilyl group, a hydrosilyl group, a carboxy group, a hydroxyl group, and a cyano group are chemically reacted after being produced according to the resin production method. It is also possible to obtain a thermosetting polyimide resin, etc.

In addition to the thermosetting resin, a radical reaction initiator such as an organic peroxide, a reaction accelerator, a cross-linking aid such as triallyl cyanurate and triallyl isocyanurate,
In order to improve heat resistance, adhesiveness, etc., if necessary, it is possible to appropriately add acid dianhydride-based, amine-based, imidazole-based generally used epoxy curing agents, various coupling agents, etc. is there.

It is also possible to mix a thermosetting resin with the thermoplastic resin for the purpose of controlling the flowability of the adhesive during heat-bonding. For this purpose, it is desirable to add 1 to 10000 parts by weight, preferably 5 to 2000 parts by weight, of the thermosetting resin to 100 parts by weight of the thermoplastic resin. If there is too much thermosetting resin, the adhesive layer may become brittle,
On the other hand, if the amount is too small, the adhesive may squeeze out or the adhesiveness may deteriorate.

As the adhesive used in the laminate of the present invention, a mixture of a thermoplastic polyimide resin and an epoxy resin and / or a cyanate resin is preferable because of good balance of adhesiveness, processability and heat resistance. When the epoxy resin is used, since the epoxy resin originally has a large dielectric constant and a large dielectric loss tangent, when 100 parts by weight or less of the epoxy resin is used when mixing with the thermoplastic resin, the dielectric constant and the dielectric loss tangent of the adhesive layer are increased. It is small and preferable. When a cyanate resin is used, since the cyanate resin originally has excellent low dielectric properties, an adhesive layer having low dielectric properties can be obtained without particularly limiting the mixing ratio.

In the laminate for a printed wiring board of the present invention, in a laminate having a metal layer on one surface of a polymer film and an adhesive layer on the other surface, a high-strength film obtained by removing only the metal layer from the laminate. The relative permittivity of the entire structure including the molecular film and the adhesive layer formed on one surface thereof is 3.5 or less,
The dielectric loss tangent is 0.02 or less, the thermal expansion coefficient is 40 ppm or less, and the glass transition temperature is 150 ° C. or more. The characteristics of the structural body composed of the above-mentioned polymer film and the adhesive layer formed on one surface thereof are determined by the characteristics and thickness configuration of the polymer film and the adhesive layer. For that reason,
It is necessary to appropriately select the chemical structure and thickness constitution of the polymer film and the adhesive layer so as to satisfy the above characteristics.

It is empirically known that the additivity rule in which the respective characteristics and volume ratios of the polymer film and the adhesive layer are taken into consideration generally holds.

The following steps can be exemplified as a method for producing a build-up multilayer printed wiring board using the laminate for a printed wiring board of the present invention. (1) The printed wiring board laminate of the present invention is press-laminated with the inner circuit surface and the adhesive surface aligned with the inner substrate. For the press lamination process, a vacuum press can be applied in addition to the single plate press, and the vacuum press is preferable from the viewpoint of biting bubbles during lamination and embedding the inner layer circuit. The heating temperature is 160 ° C to 220 ° C and is 1 to
It takes about 3 hours. (2) A via hole is formed at a required position. For drilling via holes, laser drilling is effective for forming blind vias with a small diameter.
A V-YAG laser is suitable. (3) If necessary, the via hole is cleaned by desmearing by a known method, and electroless copper plating is performed on the entire surface under the above conditions. (4) Apply photoresist or laminate. If necessary, a film-shaped one or a liquid one can be used. (5) By photolithography, a resist film is formed on a portion except a portion where a circuit is to be formed. For forming a high-density circuit, a method of exposing and developing a resist of a photosensitive material with a parallel light source is preferable. (6) A circuit is formed in the circuit portion and the via hole by electroplating by a known method. As a plating method, a method of adjusting a plating solution additive or applying a pulsed current can be applied. By combining these methods, a plating film can be attached according to the application. (7) The resist is peeled off. Usually, an alkaline solution or an organic solvent is used. (9) A circuit is formed by removing the metal layer of a portion unnecessary for the circuit by etching. (9) To continue stacking, repeat (1) to (8).

[0076]

Example 1 (Synthesis of Polyimide Film) Paraphenylenediamine (hereinafter PDA) and 4,4′-diaminodiphenyl ether (hereinafter ODA) in a separable flask.
1 equivalent of N, N-dimethylformamide (hereinafter DM
Dissolve in F). Then, 1 equivalent of p-phenylene bis (trimellitic acid monoester anhydride) (hereinafter TMHQ) was added and stirred for 30 minutes. Then, 0.9 equivalent of pyromellitic dianhydride (hereinafter PMDA) is added and stirred for 30 minutes. Then, paying attention to the increase in viscosity, a DMF solution of PMDA (concentration 7%) was added, and the viscosity at 23 ° C. was 2000 to 30.
The porosity was adjusted to 00 poise to obtain a DMF solution of a polyamic acid polymer. The amount of DMF used was such that the concentration of the diamine component and the tetracarboxylic dianhydride component charged with the monomer was 18% by weight. Also, the polymerization is 40
Performed at ° C.

With respect to 100 g of the above polyamic acid solution,
After 10 g of acetic anhydride and 10 g of isoquinoline were added and uniformly stirred, defoaming was performed, and the mixture was cast on a glass plate to give about 1
After drying at 10 ° C. for about 5 minutes, the polyamic acid coating film was peeled off from the glass plate to obtain a gel film having self-supporting property. TB with this gel film adjusted to a titanium concentration of 100 ppm
Immerse the film in 1-butanol solution of STA for 1 minute, remove the droplets on the film surface, and then fix the film on the frame.
The polyimide film having a thickness of about 12.5 μm was obtained by heating at about 1 ° C. for about 1 minute and at about 500 ° C. for about 1 minute and dehydration ring-closing drying. This polyimide film has a tensile elastic modulus of 6 GPa,
The tensile elongation was 50%, the linear expansion coefficient was 13 ppm, the water absorption rate was 1.2%, the dielectric constant was 3.4, the dielectric loss tangent was 0.01, and the 10-point average roughness Rz was 0.2 μm.

(Formation of Metal Layer) The metal layer was formed on the polyimide film produced by the above method using a sputtering apparatus NSP-6 manufactured by Showa Vacuum Co., Ltd. according to the following method. Set the polymer film in the jig and close the vacuum chamber. The substrate (polymer film) is evacuated to 6 × 10 ⁻⁴ Pa or less while rotating it on its own axis while being heated by a lamp heater. After that, introduce argon gas to 0.35
Nickel 20n by DC sputtering with Pa
m, then copper is sputtered to 100 nm. Both DC powers were sputtered at 200W. The film formation rate was 7 nm / min for nickel and 11 nm / mi for copper.
n, and the film-forming thickness was controlled by adjusting the film-forming time. (Formation of Adhesive Layer) In a glass flask having a volume of 2000 ml under a nitrogen atmosphere, 1 equivalent of bis {4- (3-aminophenoxy) phenyl} sulfone (hereinafter referred to as N, N-dimethylformamide (hereinafter referred to as DMF)) BAPS-
M). The solution was stirred while being cooled with ice water, and 1 equivalent of 4,4 ′-(4,4′-isopropylidenediphenoxy) bis (phthalic anhydride) (hereinafter, referred to as BPAD
A) was dissolved and polymerized to obtain a polyamic acid polymer solution having a solid content concentration of 30% by weight.

This polyamic acid solution was heated at 200 ° C. 180
Min., Under reduced pressure of 665 Pa, 200 ° C. was heated under reduced pressure for 3 hours to obtain a solid thermoplastic polyimide resin. The polyimide resin obtained above and a novolac type epoxy resin (Epicoat 1032H60: manufactured by Yuka Shell Co., Ltd.), and 4,
4'-diaminodiphenyl sulfone (hereinafter, 4,4 '
-DDS) was mixed at a weight ratio of 70/30/9 and dissolved in dioxolane so that the solid content concentration was 20% by weight to obtain an adhesive solution. The obtained adhesive solution was applied to the surface of the polymer film opposite to the surface on which the metal layer was formed using a comma coater so that the thickness after drying was 9 μm, and dried at 170 ° C. for 2 minutes to adhere. An agent layer was formed to produce a printed wiring board laminate. The adhesive layer of the obtained laminate for a printed wiring board is opposed to a copper foil,
A structure composed of a polyimide film and an adhesive layer obtained by curing the adhesive layer by vacuum pressing under the conditions of a temperature of 200 ° C., a pressure of 3 MPa, a vacuum degree of 10 Pa, and an hour, and then removing the metal layer and the copper foil by etching. Was evaluated. The relative dielectric constant is 3.5, the dielectric loss tangent is 0.018, the linear expansion coefficient is 32 ppm, and the glass transition temperature is 160 derived from the adhesive layer.
C. and 310.degree. C. due to the polyimide film were observed. (Production of Multilayer Printed Wiring Board) The obtained laminated body for printed wiring board was used to produce a multilayer printed wiring board. (1) Temperature of 200 on FR4 board with inner layer circuit thickness of 9μm
Laminated by pressing for 1 hour under the conditions of ° C, pressure 3 MPa, and vacuum degree 10 Pa. (3) UV-YAG laser with a diameter of 30μ at the required position
Drill a via hole of m. (4) Cleaner conditioner (product name Cleaner Securigant 902) 5 minutes, predip (product name Predip Neogantt B) 1 according to the process of Atotech electroless copper plating
Min, activator (trade name, activator neogant 834 conc) 5 minutes, reduction (trade name reducer neogant) 2 minutes electroless copper plating (novigant MSK-DK) 15 minutes. (6) After washing the electroless copper plating film with acetone, J
Liquid photoresist made by SR company (trade name THB-320
P) was applied by spin coating at 1000 RPM for 10 seconds and dried at 110 ° C. for 10 minutes to form a resist layer having a thickness of 10 μm. (7) Line / space in the resist layer is 10/10 μm
After closely adhering the glass mask of No. 1 to the UV exposure device of the ultra-high pressure mercury lamp for 1 minute, the developer (PD523 manufactured by JSR) was used.
The exposed portion was removed by immersing in AD) for 3 minutes to form a pattern of line / space = 10/10 μm. (8) The obtained laminated substrate was electroplated with a copper sulfate plating solution at a current density of 2 A / dm ² for 20 minutes, and a pattern having a thickness of 10 μm was formed on the portion where the resist was removed. (9) The obtained circuit board was washed with acetone to remove the resist layer remaining on the board. (12) The obtained circuit board was immersed for 5 minutes in an etching solution (trade name, Meck Remover NH-1862) manufactured by Mec. This etching solution has a higher nickel etching rate than copper, and it was possible to minimize damage to copper in the circuit portion when nickel in the portion other than the circuit was removed.

The circuit of the obtained multilayer printed wiring board was observed with a scanning electron microscope, and line / space = as designed.
It was confirmed that a circuit of 10/10 μm was formed.
Further, the space portion was smooth and no nickel or copper etching residue was observed. Furthermore, the cross-sectional shape of the copper conductor circuit, which should originally be rectangular, did not show circuit thinning during the etching process, and maintained the rectangular shape as designed. Further, the peel strength from the polymer film when the thickness of the metal conductor layer was 20 μm was 6.8 N / cm, which was a sufficient peel strength for forming high-density wiring.

Example 2 In the synthesis of the polyimide film of Example 1, 1 equivalent of PDA was 4,4'-diaminobenzanilide (hereinafter referred to as DABA), and TMHQ1 was used.
Equivalent to PMH 0.9 equivalent to TMHQ 1.9 equivalent,
The same operation was performed except that the DMF solution of PMDA was changed to the DMF solution of TMHQ to obtain a polyimide film having a thickness of 12.5 μm. This polyimide film has a tensile elastic modulus of 9 GPa, a tensile elongation of 15% and a linear expansion coefficient of 6 pp.
m, water absorption 1.2%, dielectric constant 3.4, dielectric loss tangent 0.0
The 1 and 10 point average roughness Rz was 0.2 μm. The obtained polyimide film was processed in the same manner as in Example 1 to prepare a laminate for a printed wiring board. The adhesive layer of the obtained laminate for a printed wiring board is opposed to a copper foil, and the temperature is 200 ° C.
The adhesive layer is cured by a vacuum press under the conditions of a pressure of 3 MPa, a degree of vacuum of 10 Pa, and an hour, and then the characteristics of a structure composed of a polyimide film and an adhesive layer obtained by removing the metal layer and the copper foil by etching are evaluated. did. Dielectric constant 3.5, dielectric loss tangent 0.019, linear expansion coefficient 24ppm,
As the glass transition temperature, 160 ° C. derived from the adhesive layer and 300 ° C. derived from the polyimide film were observed. Example 1
A multilayer printed wiring board was obtained by the same operation as.

The circuit of the obtained multilayer printed wiring board was observed with a scanning electron microscope, and line / space =
It was confirmed that a circuit of 10/10 μm was formed.
Further, the space portion was smooth and no nickel or copper etching residue was observed. Furthermore, the cross-sectional shape of the copper conductor circuit, which should originally be rectangular, did not show circuit thinning during the etching process, and maintained the rectangular shape as designed. Further, the peel strength from the polymer film when the thickness of the metal conductor layer was 20 μm was 6.8 N / cm, which was a sufficient peel strength for forming high-density wiring.

Comparative Example 1 An interlayer insulating material made of epoxy resin (ABF-SH-9K manufactured by Ajinomoto Fine-Techno Co., Inc.) was laminated on a FR4 substrate having a circuit thickness of 9 μm at a temperature of 90 ° C. and cured at 170 ° C. for 30 minutes.

The obtained laminated body was subjected to surface roughening by desmear by the permanganate method, and then the multilayer printed wiring board was manufactured and evaluated through the steps (3) and after of the above method for manufacturing a multilayer printed wiring board. . The 10-point average roughness of the resin surface after the surface roughening was 3.0 μm. Since the obtained multilayer printed wiring board had large irregularities on the resin surface, the stable circuit width was not stable. In addition, when the space portion was observed by SEM, nickel etching lumps were found on the irregularities.
The adhesion strength between the resin layer and the metal conductor layer was 7.4 N / cm. Although the epoxy resin was cured under the above conditions, the relative dielectric constant was 3.5, the dielectric loss tangent was 0.030, the linear expansion coefficient was 70 ppm, and the glass transition temperature was 186 ° C.

[0085]

[0086]

The laminate for a printed wiring board according to the present invention has an extremely thin metal layer on its surface, and this metal layer improves the peeling strength between the polymer film and the electroless plating film. Therefore, even in the case of a polymer film having a smooth surface, the electroless plating firmly adheres to the film, which is suitable for forming a high-density circuit of line / space = 25 μm / 25 μm or less. Further, it has a low dielectric property, a small linear expansion property, a high glass transition temperature, and is suitable for manufacturing a printed wiring board, particularly a build-up wiring board.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) // C08L 79:08 C08L 79:08 ZF term (reference) 4F006 AA39 AB34 AB38 BA01 CA08 DA01 DA04 4F100 AB01B AB16 AB17 AB33 AK01A AK45A AK45C AK45G AR00C BA03 BA07 BA10B BA10C CC01 EH66 GB43 JA05 JA05A JG05 JG05A JL11 5E346 AA12 AA15 CC10 CC32.

Claims (4)

[Claims] 1. A laminate in which a metal layer is provided on one surface of a polymer film and an adhesive layer is provided on the other surface, and the polymer film is obtained by removing only the metal layer from the laminate and the polymer film is formed on one surface thereof. The relative permittivity of the entire structure including the adhesive layer is 3.5 or less, the dielectric loss tangent is 0.02 or less, and the thermal expansion coefficient is 40p.
A laminated body for a printed wiring board, having a pm or lower and a glass transition temperature of 150 ° C. or higher. 2. The laminate for a printed wiring board according to claim 1, wherein the polymer film is a polyimide film. 3. The laminate for a printed wiring board according to claim 1, wherein the metal layer provided on one surface of the polymer film is formed by a physical method. 4. The printed wiring board laminate according to claim 1, wherein the adhesive layer contains a polyimide resin. 5. A printed wiring board using the laminate for a printed wiring board according to claim 1.