JPH10284840A - Manufacture of multilayered printed wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a multilayered board having small-diameter holes by boring a non-through hole into a specific epoxy adhesive film coated with copper foil and integrally piling up an inner circuit board upon the thermosetting epoxy resin composition layer of the adhesive film and a release sheet and a mirror plate on the copper foil of the adhesive film, and then, connecting the copper foil to an inner-layer circuit by plating the inside of the non-through hole. SOLUTION: A non-through hole 4 having a diameter of 0.15 mm is bored into an epoxy adhesive film 3 coated with copper foil 1 and containing a thermosetting epoxy resin composition layer 2 composed of a halogenated epoxy copolymer having a heavy molecular weight of >=100,000 for roughening the surface of the foil 1, a crosslinking agent, and a polyfunctional epoxy resin. An inner- layer circuit board 5 is integrally piled upon the layer 2 of the film 3 and a release sheet 6 and a mirror surface are successively laminated upon the surface of the foil 1. After the epoxy resin composition 7 of the layer 2 oozing out in the hole 4 is removed and a through hole is opened and plated with copper, a multilayered printed wiring board having a non-through hole in its surface layer can be formed by forming outer-layer wiring. The diameter of the hole 4 is adjusted to 0.13 mm at the opening and 0.12 mm at the bottom.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for manufacturing a multilayer printed wiring board.

[0002]

2. Description of the Related Art In recent years, the density of a multilayer printed wiring board has been increased, and a method of connecting electric connections between circuit layers with non-through holes has been studied. An insulating adhesive film with copper foil provided with an insulating adhesive layer on one side is pre-punched with holes for interlayer connection, laminated on an inner circuit board, and the circuit on the inner circuit and the insulating adhesive film with copper foil are laminated. A method of electrically connecting copper foils is known. Further, a method is also known in which a sheet that plastically flows in a laminating process is stacked on an insulating adhesive film with a copper foil to prevent the insulating layer resin from seeping out into a pre-drilled hole.

[0003]

In the method of manufacturing a multilayer printed wiring board, when the diameter of the non-through hole is large, the exudation of the insulating layer resin is small, or the exudation is prevented by the plastic flowing sheet. By doing so, sufficient electrical connection was possible, but in a multilayer printed wiring board with a higher density, the hole diameter of the non-through hole was 20 mm.
There is a growing demand for a sheet having a thickness of 0 μm or less, and it is insufficient to prevent the resin in the insulating layer from seeping out by a plastically flowing sheet, and it has been impossible to make a sufficient electrical connection.

An object of the present invention is to provide a method of manufacturing a multilayer printed wiring board having excellent connection reliability even with a small hole diameter.

[0005]

According to the method of manufacturing a multilayer printed wiring board of the present invention, a copper foil having a molecular weight of 10
An epoxy adhesive film 3 with a copper foil provided with a semi-cured thermosetting epoxy resin composition layer 2 composed of a halogenated high molecular weight epoxy polymer of not less than 000, a crosslinking agent and a polyfunctional epoxy resin. Then, a hole 4 serving as a non-through hole for interlayer connection is opened, and the thermosetting epoxy resin composition layer 2 of the epoxy adhesive film 3 with copper foil is overlapped so as to be in contact with an inner circuit board 5 prepared in advance. A release sheet 6 and a mirror plate are stacked on the outside of the copper foil 1 of the epoxy adhesive film 3 with a foil, and the epoxy resin composition 7 which has been laminated and integrated by heating and pressing is extruded into a non-through hole portion. The inner circuit and the copper foil are electrically connected by removing with a resin etching solution composed of an alcohol solvent and an amide solvent, plating the non-through hole, and electrically connecting the inner layer circuit and the copper foil.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION

(Copper foil) As the copper foil used for the epoxy adhesive film with a copper foil of the present invention, a copper foil having a thickness of 12 μm or more produced by an electrolytic method or a rolling method can be used. A copper foil thinner than that supported by a carrier layer can be used to improve the handleability.

(Thermosetting Epoxy Resin Composition Layer) The halogenated high molecular weight epoxy polymer having a molecular weight of 100,000 or more used in the present invention comprises a bifunctional epoxy resin and a halogenated bifunctional phenol compound as a bifunctional epoxy resin. The compounding equivalent ratio of the halogenated bifunctional phenols is set to an epoxy group / phenolic hydroxyl group = 1 / 0.9 to 1 / 1.1, in an amide or ketone solvent having a boiling point of 130 ° C. or more in the presence of a catalyst, It is obtained by heating and polymerizing at a reaction solid concentration of 50% by weight or less.

The bifunctional epoxy resin may be any compound as long as it has two epoxy groups in the molecule, such as bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, Examples include aliphatic chain epoxy resins. These compounds can have any molecular weight. Some of these compounds can be used in combination. Further, components other than the bifunctional epoxy resin may be contained as impurities.

The halogenated bifunctional phenol may be any compound having a halogen atom and two phenolic hydroxyl groups. Examples thereof include monocyclic bifunctional phenols such as hydroquinone, resorcinol, catechol and polycyclic phenol. Bisphenol A, a bifunctional phenol,
Examples include bisphenol F, naphthalene diols, bi (s) phenols, and halides of these alkyl group-substituted products. These compounds can have any molecular weight. These compounds may be used in combination of several kinds, or non-halogenated bifunctional phenols may be used in combination. Further, components other than the bifunctional phenols may be included as impurities.

The catalyst may be any compound having a catalytic ability to promote the etherification reaction between the epoxy group and the phenolic hydroxyl group. Examples thereof include alkali metal compounds, alkaline earth metal compounds, imidazoles, and organic compounds. Phosphorus compounds, secondary amines, tertiary amines, quaternary ammonium salts and the like. Among them, alkali metal compounds are the most preferred catalysts. Examples of alkali metal compounds include sodium, lithium and potassium hydroxide,
Organic acid salts, alcoholates, phenolates, hydrides, borohydrides, amides and the like. These catalysts can be used in combination.

The reaction solvent is preferably an amide or ketone solvent, and the amide solvent has a boiling point of 130.
As long as the raw material epoxy resin and phenols are dissolved at a temperature of not less than ℃, there is no particular limitation, for example, formamide, N
-Methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-
Examples include dimethylacetamide, N, N, N ', N'-tetramethylurea, 2-pyrrolidone, N-methyl-2-pyrrolidone, carbamic acid esters and the like. These solvents can be used in combination. Further, it may be used in combination with other solvents typified by ketone solvents, ether solvents and the like.

As for the conditions for synthesizing the polymer, the blending equivalent ratio of the bifunctional epoxy resin and the halogenated difunctional phenol is as follows: epoxy group / phenolic hydroxyl group = 1: 0.9 to
1.1 is desirable. The amount of the catalyst is not particularly limited, but is generally about 0.0001 to 0.2 mol per 1 mol of the epoxy resin. The polymerization temperature is desirably 60 to 150 ° C. When the temperature is lower than 60 ° C., the reaction for increasing the molecular weight is remarkably slow, and when the temperature is higher than 150 ° C., the side reaction increases and the molecular weight is not increased linearly. The concentration of the solid content at the time of the polymerization reaction using a solvent may be 50% by weight or less, and more preferably 30% by weight or less.

Thus, a halogenated high molecular weight epoxy polymer having a molecular weight of 100,000 or more is obtained. As a crosslinking agent for this high-molecular-weight epoxy polymer, a mask isocyanate obtained by masking (blocking) an isocyanate with a compound having another active hydrogen, in which the reactivity of the crosslinking agent is easily controlled and the storage stability of the varnish is easily ensured. Can be used. The isocyanates may be any as long as they have two or more isocyanate groups in the molecule. Examples thereof include diisocyanate and tolylene diisocyanate. In particular, isophorone diisocyanate and tolylene diisocyanate masked with a phenol for improving the heat resistance of the cured product are preferable. The amount of the crosslinking agent is preferably from 0.1 to 1.0 equivalent of the isocyanate group based on 1.0 equivalent of the alcoholic hydroxyl group of the high molecular weight epoxy polymer.

The polyfunctional epoxy resin may be any compound as long as it has two or more epoxy groups in the molecule. Examples thereof include a phenol novolak type epoxy resin, a cresol novolak type epoxy resin, and a resol type epoxy resin. Epoxy resins such as glycidyl ethers of phenols, such as bisphenol epoxy resins, alicyclic epoxy resins, epoxidized polybutadienes, glycidyl ester epoxy resins, glycidyl amine epoxy resins, isocyanurate epoxy resins, and flexible epoxy resins In particular, a phenolic epoxy resin or a mixture of a phenolic epoxy resin and a polyfunctional epoxy resin is preferable for improving heat resistance.
The amount of the polyfunctional epoxy resin is preferably 20 to 100 parts by weight based on the high molecular weight epoxy polymer.

These polyfunctional epoxy resins may be used alone or in combination of two or more. Further, a curing agent and a curing accelerator of the polyfunctional epoxy resin are used.
Examples of epoxy resin curing agents and curing accelerators include novolak type phenol resins, dicyandiamide, acid anhydrides, amines, imidazoles, phosphines, and the like. Further, these may be used in combination. Further, a silane coupling agent may be added. As the silane coupling agent to be added, epoxy silane, amino silane, urea silane and the like are preferable.

(Epoxy Adhesive Film with Copper Foil) In order to provide this thermosetting epoxy resin composition as a semi-cured thermosetting epoxy resin composition layer 2 on the matte side of a copper foil, the molecular weight is 100. An adhesive varnish is prepared by mixing a halogenated high molecular weight epoxy polymer of 2,000 or more, a crosslinking agent and a polyfunctional epoxy resin, and a post-metering coating method such as a blade coater, a naf coater, and a squeeze coater,
The thermosetting epoxy resin composition is applied by a pre-metering coating method such as a reverse roll coater, a kiss roll coater, a cast coater, a spray coater, or an extrusion coater, and semi-cured while evaporating the solvent.

Further, the above-mentioned thermosetting epoxy resin composition varnish is applied on a supporting film such as a polyethylene terephthalate film, and the thermosetting epoxy resin composition is semi-cured while evaporating the solvent, and the supporting film is peeled off. Then, the film can be bonded to the mat surface of the copper foil. This thermosetting epoxy resin composition layer 2 is formed by applying and drying two or more times,
It can also be formed using more than one filmed thermosetting epoxy resin composition.

(Hole to be a non-through hole) Further, at the hole 4 to be a non-through hole for interlayer connection in the epoxy adhesive film 3 with copper foil, a thermosetting epoxy resin composition It is possible to prevent the laminate and the end plate from adhering due to the flow and seepage of the layer itself.

(Release Sheet) As a release sheet suitable for this purpose, for example, a 25 μm-thick Tedlar sheet (trade name, manufactured by DuPont) is preferably used.

(Inner Circuit Board) As the double-sided wiring board for the inner layer of the present invention, a glass epoxy copper-clad laminate, a paper phenol copper-clad laminate, a composite copper-clad laminate, a polyimide copper-clad laminate, or the like can be used. After drilling through holes in these copper-clad laminates, copper plating is performed, and copper in unnecessary portions is removed by etching, so that an inner-layer double-sided wiring board with through holes can be manufactured. Further, the method is not necessarily limited, and a hole is formed in an insulating substrate containing a plating catalyst therein or a substrate having an electroless plating adhesive applied to the surface of the insulating substrate to form a circuit. It is also possible to use a double-sided plate having a through hole, which is produced by forming a plating resist at a portion where it is not formed and performing plating.

(Removal of Epoxy Resin Composition) The resin etching solution used in the present invention is prepared by mixing and mixing an alkali metal hydroxide, an alcohol solvent and an amide solvent. Here, any alkali metal hydroxide may be used, and examples thereof include lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, and cesium hydroxide. Of these, sodium hydroxide and potassium hydroxide are particularly preferred because of their high etching properties of the epoxy resin composition.

Here, the alcohol solvent may be any solvent, for example, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, iso-butanol, tert-butanol, 1-pentanol. 2-pentanol, 3-pentanol, 2-methyl-1-butanol, iso-pentyl alcohol, tert-pentyl alcohol, 3-methyl-2-butanol, neopentyl alcohol, 1-
Hexanol, 2-methyl-1-pentanol, 4-methyl-2-pentanol, 2-ethyl-1-butanol, 1-heptanol, 2-heptanol, 3-heptanol, cyclohexanol, 1-methylcyclohexanol, -Methylcyclohexanol, 3-methylcyclohexanol, 4-methylcyclohexanol, ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol mono Ethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, triethylene Recall, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, tetraethylene glycol, polyethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, glycerin,
And dipropylene glycol. Of these, diethylene glycol monomethyl ether, triethylene glycol, # 300 (this number represents the average molecular weight,
For example, # 300 means that the average molecular weight is 300. The following polyethylene glycols are particularly preferred because of their high solubility of alkali metal hydroxides and high etchability of the epoxy resin composition. Some of these solvents can be used in combination.

Here, the amide solvent may be any solvent, for example, formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N
-Methylacetamide, N, N-dimethylacetamide, N, N, N ', N'-tetramethylurea, 2-pyrrolidone, N-methyl-2-pyrrolidone, carbamic acid esters and the like. Of these, N, N-dimethylformamide, N, N-dimethylacetamide, and N-methyl-2-pyrrolidone are particularly preferred because they have an effect of swelling the epoxy resin composition and have good solubility of decomposed products. These solvents can be used in combination. Further, it may be used in combination with other solvents typified by ketone solvents, ether solvents and the like.

The ketone solvent which can be used in combination here may be any solvent, for example, acetone, ethyl ethyl ketone, 2-pentanone, 3-pentanone, 2-hexanone, methyl isobutyl ketone, 2-heptanone, 4-heptanone, Examples include diisobutyl ketone and cyclohexanone.

The ether solvent that can be used in combination here may be any solvent, for example, dipropyl ether, diisopropyl ether, dibutyl ether, anisole,
Examples include phenetole, dioxane, tetrahydrofuran, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, and the like.

The concentration of the alkali metal hydroxide in the resin etching solution may be any concentration,
A range of 5% by weight is preferred. When the amount is less than 0.5% by weight, the decomposition rate of the cured epoxy resin decreases, and when it exceeds 5% by weight, the alkali metal hydroxide cannot be completely dissolved.

The concentration of the alcohol-based solvent in the resin etching solution may be any concentration, but may be from 4.5 to 30.
A range of weight% is preferred. If it is less than 4.5% by weight,
If the alkali metal hydroxide cannot be dissolved, and exceeds 30% by weight, the etching property of the epoxy resin composition deteriorates, which is not preferable.

The concentration of the amide solvent in the resin etching solution may be any concentration, but is preferably in the range of 65 to 95% by weight. When the content is less than 65% by weight, the etching property of the epoxy resin composition is reduced, and when the content is more than 95% by weight, the concentration of the alkali metal hydroxide and the concentration of the alcohol solvent are undesirably reduced.

[0029]

【Example】

Example 1 As shown in FIG. 1A, as an epoxy adhesive film 3 with a copper foil, a thickness of 50 μm was applied to a roughened surface of a copper foil 1 having a thickness of 18 μm.
An MCF-3000E (trade name, manufactured by Hitachi Chemical Co., Ltd.), which is formed by applying a μm thermosetting epoxy resin composition layer 2 and is in a semi-cured state, is prepared. A hole 4 serving as a non-through hole having a hole diameter of 0.15 mm was drilled in the epoxy adhesive film 3 with a copper foil. Next, an inner layer circuit board 5 prepared in advance and an epoxy adhesive film 3 with a perforated copper foil
And a 25 μm-thick Tedlar sheet (trade name, manufactured by DuPont) as a release sheet 6 outside the copper foil 1 surface of the copper-foiled epoxy adhesive film 3, and a 3 mm-thick stainless steel end plate on the outside. Are laminated in this order, and heated under pressure at a temperature of 170 ° C. and a pressure of 2.5 MPa for 60 minutes to be laminated and integrated, the end plate is removed, the release sheet 6 is peeled off, and FIG. Was obtained. next,
The epoxy resin composition 7 extruded into the non-through hole portion was added to a resin etching solution containing 3% by weight of sodium hydroxide, 22% by weight of diethylene glycol monomethyl ether, and 75% by weight of N, N-dimethylformamide at 60 ° C. and 30%.
It was removed by immersion for a minute. Thereafter, the substrate was washed with running water for 5 minutes and dried at 70 ° C. for 10 minutes (FIG. 1C).
Shown in ). Next, as shown in FIG.
After drilling a 3 mm through hole and performing copper plating with a thickness of 12 μm, unnecessary portions of copper are removed by etching to form an outer layer wiring, and as shown in FIG. A high-density multilayer printed wiring board having through holes was obtained. In the multilayer printed wiring board, the size of the non-through hole is
The opening has a hole diameter of 0.13 mm and the bottom has a hole diameter of 0.1 mm.
12 mm, immersed in hot oil at 260 ° C. for 10 seconds, and immersed in water at 20 ° C. for 10 seconds even after performing 100 cycles of the hot oil test, which is one cycle.
The rise in electrical resistance was within 10%.

Example 2 The same operation as in Example 1 was carried out except that a resin etching solution consisting of 3% by weight of potassium hydroxide, 22% by weight of diethylene glycol monomethyl ether and 75% by weight of N, N-dimethylformamide was used. A high-density multilayer printed wiring board having a non-through hole was obtained. In the multilayer printed wiring board, the size of the non-through hole is such that the hole diameter of the opening is 0.13 mm, the hole diameter of the bottom is 0.10 mm, and immersed in hot oil at 260 ° C. for 10 seconds; 20
Even after 100 cycles of a hot oil test in which immersion in water at 10 ° C. for 10 seconds was one cycle, the increase in electrical resistance was within 10%.

Example 3 Sodium hydroxide 3% by weight, triethylene glycol 2
A high-density multilayer printed wiring board having a non-through hole in the surface layer was obtained in the same manner as in Example 1, except that a resin etching solution consisting of 7% by weight and 70% by weight of N, N-dimethylformamide was used. . In the multilayer printed wiring board, the size of the non-through hole is such that the hole diameter of the opening is 0.13 mm.
And the bottom hole diameter is 0.10 mm,
Immersion in hot oil for 10 seconds and immersion in water at 20 ° C. for 10 seconds as one cycle
Even after 0 cycles, the increase in electrical resistance was within 10%.

Example 4 Sodium hydroxide 3% by weight, # 300 polyethylene glycol 27% by weight, N, N-dimethylformamide 70
A high-density multilayer printed wiring board having a non-through hole in the surface layer was obtained by performing the same operation as in Example 1 except that a resin etching solution consisting of wt% was used. In the multilayer printed wiring board, the size of the non-through hole is such that the hole diameter of the opening is 0.
13 mm, the bottom hole diameter is 0.08 mm,
Even after performing 100 cycles of the hot oil test in which immersion in hot oil at 260 ° C. for 10 seconds and immersion in water at 20 ° C. for 10 seconds is one cycle, the increase in electric resistance is 1
It was within 0%.

Example 5 The same operation as in Example 1 was performed except that a resin etching solution consisting of 3% by weight of sodium hydroxide, 22% by weight of diethylene glycol monotyl ether, and 75% by weight of N, N-dimethylacetamide was used. A high-density multilayer printed wiring board having non-through holes in the surface layer was obtained. In the multilayer printed wiring board, the size of the non-through hole is such that the hole diameter of the opening is 0.13 mm, the hole diameter of the bottom is 0.08 mm, and immersed in hot oil at 260 ° C. for 10 seconds; 20
Even after 100 cycles of a hot oil test in which immersion in water at 10 ° C. for 10 seconds was one cycle, the increase in electrical resistance was within 10%.

Example 6 The same operation as in Example 1 was carried out except that a resin etching solution comprising 3% by weight of sodium hydroxide, 22% by weight of diethylene glycol monomethyl ether and 75% by weight of N-methyl-2-pyrrolidone was used. A high-density multilayer printed wiring board having non-through holes in the surface layer was obtained. In the multilayer printed wiring board, the size of the non-through hole is such that the hole diameter of the opening is 0.13 mm, the hole diameter of the bottom is 0.10 mm, and immersed in hot oil at 260 ° C. for 10 seconds; 20
Even after 100 cycles of a hot oil test in which immersion in water at 10 ° C. for 10 seconds was one cycle, the increase in electrical resistance was within 10%.

COMPARATIVE EXAMPLE 1 Thickness of plastic flow 1 during lamination process without using release sheet
The same operation as in Example 1 was performed except that a 50 μm opulan sheet (trade name, manufactured by Mitsui Petrochemical Industry Co., Ltd.) was used to prevent exudation of the resin in the non-penetrating portion, and that no resin etching solution was used. . When the obtained non-through hole was confirmed, it was not possible to prevent the exudation of the resin, and it was not possible to connect to the inner layer circuit.

Comparative Example 2 The same operation as in Example 1 was performed except that the exuded epoxy resin composition was removed using an alkaline permanganate solution without using a resin etching solution. When the obtained non-through hole was confirmed, the exuded resin could not be removed, and connection with the inner layer circuit could not be made.

[0037]

According to the method for manufacturing a multilayer printed wiring board of the present invention, a high-density multilayer printed wiring board having a non-through hole of 200 μm or less in the surface layer can be manufactured.

[Brief description of the drawings]

FIGS. 1A to 1E are cross-sectional views showing respective manufacturing steps for explaining one embodiment of the present invention.

[Explanation of symbols]

 1. Copper foil 2. 2. Thermosetting epoxy resin composition layer 3. Epoxy adhesive film with copper foil 4. Holes that become non-through holes Inner layer circuit board 6. Release sheet 7. Epoxy resin composition exuded into non-through holes

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiromi Takahashi 1500 Oji Ogawa, Shimodate City, Ibaraki Pref.Hitachi Chemical Industry Co., Ltd. Inside Shimodate Research Laboratory (72) Inventor: Shoji Nakaso 1500 Ogawa Oji, Shimodate City, Ibaraki Prefecture, Hitachi Chemical Industry Co., Ltd.

Claims (5)

[Claims] 1. A copper foil having a molecular weight of 100,
Epoxy adhesive film with copper foil provided with a semi-cured thermosetting epoxy resin composition layer (2) comprising a halogenated high molecular weight epoxy polymer of 000 or more, a crosslinking agent and a polyfunctional epoxy resin (3) ), A hole (4) serving as a non-through hole for interlayer connection is formed, and the thermosetting epoxy resin composition layer (2) of the epoxy adhesive film with copper foil (3) is prepared in advance in the inner circuit board ( 5), a release sheet (6) and a mirror plate are stacked on the outside of the copper foil (1) of the epoxy adhesive film with copper foil (3), and laminated by heating and pressing to form a non-through hole. The exuded epoxy resin composition (7) is removed with a resin etching solution composed of an alkali metal hydroxide, an alcohol-based solvent, and an amide-based solvent, and plating is applied to the non-through hole to remove the inner layer circuit and the copper foil. Electrically connected Method for manufacturing a multilayer printed wiring board according to claim Rukoto. 2. A non-through hole (4) having a hole diameter of 200
The method for producing a multilayer printed wiring board according to claim 1, wherein the thickness is not more than μm. 3. An alkali metal hydroxide of a resin etching solution is sodium hydroxide or potassium hydroxide,
3. The method for producing a multilayer printed wiring board according to claim 1, wherein the compound is present in the resin etching solution at a concentration of 0.5 to 5% by weight. 4. An alcohol-based solvent for a resin etching solution,
3. selected from the group consisting of diethylene glycol monomethyl ether, triethylene glycol, polyethylene glycol of # 300 or less, or a combination thereof;
The method for producing a multilayer printed wiring board according to any one of claims 1 to 3, wherein the compound is present in the resin etching solution at a concentration of 5 to 30% by weight. 5. The method of claim 1, wherein the amide solvent of the resin etching solution is N, N
Selected from the group consisting of -dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, or a combination thereof, and present in the resin etching solution at a concentration of 65 to 95% by weight. Item 5. The method for producing a multilayer printed wiring board according to any one of Items 1 to 4.