JPH0854732A - Etching resist sheet and production of printed wiring board - Google Patents

Abstract

PURPOSE:To obtain an etching resist sheet easy in coating a plated through hole, high in pattern forming accuracy and excellent in workability for mass production by providing a layer of a 1st resin composition low in fluidity due to heating on a protective film and a layer of a 2nd resin composition high in fluidity due to heating thereon. CONSTITUTION:This etching resist sheet is formed by providing the layer 2 of the 1st resin composition soluble in alkali, low in fluidity due to heating and sensitive to active energy beam on the protective film 1 and the layer 3 of the 2nd resin composition soluble in alkali, high in fluidity due to heating and sensitive to active energy beam thereon. The 1st and 2nd resin composition are polymers consisting essentially of acrylic acid and/or methacrylic acid and (meth)acrylate. And the resin compositions are composed of a linear polyrner, which is made by adding an ethylenic unsaturated compound having glycidyl group to a part of carboxyl group originated from (meth)acrylic acid of the structural unit, as a base polymer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides an etching resist sheet for a high-density printed wiring board, which can easily fill or block an insulating resin in a plated through hole and has a smooth surface.

[0002]

2. Description of the Related Art As electronic devices have become smaller and more multifunctional,
Printed wiring boards are moving toward higher density. For example, thinning conductor circuits, increasing the number of layers, and blind ho
There are small diameters of through holes including interstitial via holes such as holes and ball holes, and high-density mounting by surface mounting of small chip parts.

Conventional etching resists for printed wiring boards include printing inks, dry films and liquid resists. As a method of manufacturing a printed wiring board having through holes, a copper clad laminate is subjected to hole processing, panel plating by copper plating is performed, and after a dry film is tented, a pattern is formed and used as an etching resist, and then etching is performed. Then, there is a method of manufacturing a copper through-hole printed wiring board. However, in this method, if the etching resist is left with a diameter larger than the diameter of the plated through hole in consideration of the deviation of the pattern formation, the plated through hole cannot be completely covered with the dry film and the cover cannot be sufficiently covered. If not done, there is a drawback that the plating through hole is partially dissolved due to the etching solution entering into the plating through hole. Therefore, the land diameter of the plated through hole is limited, and it is not suitable for higher density wiring.

On the other hand, it has also been attempted to laminate the dry film under vacuum to narrow the resin layer of the dry film into the holes to reduce the land diameter of the plated through holes. However, there is a drawback that the laminating apparatus becomes large and expensive, and the laminating speed becomes slow, so that the productivity is lowered.

After forming the plated through hole, an etching resist is embedded in the plated through hole by screen printing, roll coating or the like to be dried or cured, and then unnecessary resist on the surface is removed by polishing to include the filled portion. There is a method of forming a pattern on a required pattern portion with a screen printing ink or a dry film. However, the pattern formation of the etching resist by screen printing tends to leave a jagged mesh on the screen, and it is difficult to form a pattern of 150 μm or less. The method of further forming the dry film in the hole filling portion has a drawback that the hole filling step and the dry film pattern forming step are lengthened and the productivity is deteriorated.

Further, a liquid etching resist is applied to the plated through hole and the surface of the panel by screen printing, roll coating, electrostatic coating or curtain coating on a panel having a plated through hole and dried, and an etching resist pattern is formed by exposure and development. There is a method of manufacturing a copper through hole printed wiring board by etching. Similarly, instead of the liquid resist, there is also a method of electrodeposition coating an etching resist.

As resists, there are a negative type resist which is cured by irradiation with active energy rays due to photosensitivity and a positive type resist which can be dissolved in an alkaline aqueous solution or the like by irradiation with active energy rays. For negative resist, it is necessary to irradiate the resist in the plated through hole with ultraviolet rays,
It is difficult to completely irradiate the inside of the plated through-hole wall, and pinholes are likely to occur during etching. On the other hand, the positive type resist is usually exposed to ultraviolet rays on the part to be etched other than the plated through holes, but the through holes that do not require plating, such as guide holes and reference holes, are irradiated with ultraviolet rays and etched. The resist needs to be removed during development. However, it is difficult to reliably irradiate the etching resist on the hole wall with ultraviolet rays, and there is a problem that plated copper residue is generated on the hole wall.

[0008]

DISCLOSURE OF THE INVENTION The present invention eliminates the above-mentioned drawbacks of the conventional method, easily coats plated through holes, has high pattern formation accuracy, and is excellent in mass production workability, and a printed wiring board using the same. The present invention provides a method for manufacturing the same.

[0009]

In order to solve the above problems, the inventors of the present invention have conducted diligent studies, and as a result, as a result of heating on a protective film capable of peeling a layer of a resin composition described later, which is soluble in alkali and flows by heating. A layer of a first resin composition having a small property and sensitive to active energy rays is provided, and a layer of a second resin composition which is soluble in alkali and has a high fluidity by heating and is sensitive to active energy rays is further provided thereon. The inventors have invented an etching resist sheet made of

As described above, the resist has photosensitivity.
Although it can be classified into a negative type and a positive type, it is preferable to use the negative type because it is inexpensive, has a high sensitivity to active energy rays, and has a wide pH range of a developing solution at the time of development, which facilitates development. The negative resist will be described below unless otherwise specified.

Furthermore, in the present invention, the first and second resin compositions contain acrylic acid and / or methacrylic acid (hereinafter referred to as "(meth) acrylic acid") and (meth) acrylic acid ester as main components. The polymer, which is a structural unit, a part of the carboxyl group derived from (meth) acrylic acid, a linear polymer having an ethylenically unsaturated compound having a glycidyl group added to the base polymer, Is a composition in which a crosslinking agent, an active energy ray curing reaction initiator and an active energy ray curing sensitizer are blended, and the molecular weight of each base polymer is 20,000 to 200, 000, the second resin composition is 1,000 to 50,000 and smaller than the first resin composition.

Here, the fact that the fluidity due to heating is large means that
Heating in the step of laminating the resin composition side of the etching resist sheet of the present invention on a plated panel having a plated through hole, that is, approximately 60 to 120 ° C.
In the temperature range in which the resin composition is not thermoset, the layer of the resin composition is melted and easily flows into the plated through hole of the plated panel to fill the plated through hole.

In the etching resist sheet used in the present invention, the first and second resin compositions are (meth)
A polymer mainly composed of acrylic acid and (meth) acrylic acid ester, wherein an ethylenically unsaturated compound having a glycidyl group is added to a part of a carboxyl group derived from (meth) acrylic acid which is a constitutional unit of the polymer. It is preferable that the main component is a base polymer which is composed of an added linear polymer and is soluble in an alkaline aqueous solution. In the base polymer,
When a polymerizable compound having, for example, one or more terminal ethylene groups as a cross-linking agent, an active energy ray curing reaction initiator and an active energy ray curing sensitizer are added, the first and second resin compositions are obtained, Further, a thermosetting agent, a flame retardant, a coloring pigment, a moisture resistant pigment, a defoaming agent, a leveling agent, a thixotropic agent, a polymerization inhibitor, an anti-settling agent and the like can be appropriately added depending on the type and purpose.

The fluidity of the first and second resin compositions used in the etching resist sheet of the present invention upon heating can be controlled by the molecular weight of the base polymer, the type of crosslinking agent and the amount of crosslinking agent. That is, the smaller the molecular weight of the base polymer, the use of a crosslinking agent having a higher fluidity before curing, and the greater the amount of the crosslinking agent, the greater the fluidity of the resin composition due to heating.

As the base polymer (hereinafter simply referred to as "base polymer") constituting the first and second resin compositions which are soluble in alkali and are sensitive to active energy rays used in the present invention, an acryloyl group and / or Alternatively, an acrylic resin and / or a methacrylic resin soluble in a photosensitive alkaline aqueous solution containing a photopolymerizable or photodimerizable photosensitive group such as a methacryloyl group (hereinafter referred to as “(meth)”
It is called "acrylic resin". It is preferable to use) because it is easy to control the molecular weight during production and a high molecular weight is obtained.

The concentration of the photosensitive group in the base polymer is preferably 0.1 to 5.0 meq / g, more preferably 0.3 to 4.0 meq / g. If the concentration of the photosensitive group is too low, the photocurability deteriorates, and if it is too high, the storage stability deteriorates.

Examples of the base polymer include (meth) acrylic acid ester, vinyl monomers such as styrene and acrylonitrile, N-phenylmaleimide, and the like, and (meth)
A copolymer obtained by ring-opening addition of an ethylenically unsaturated compound having a glycidyl group such as glycidyl acrylate and / or glycidyl methacrylate (hereinafter referred to as "glycidyl (meth) acrylate") to a copolymer with acrylic acid (hereinafter referred to as "opening"). The term "cycloaddition product") is more preferable because it has good heat resistance.

The ring-opening adduct is a solvent (for example, ethers such as diglyme, ethyl carbitol acetate,
Ethyl cellosolve acetate, isopropyl acetate, etc. esters, methyl ethyl ketone, cyclohexanone, etc. ketone)) and dissolve the copolymer, and then react the glycidyl (meth) acrylate as it is or by diluting it with a solvent To be

At this time, a radical polymerization inhibitor such as hydroquinone, hydroquinone monomethyl ether or phenothiazine is added in an amount of 10 to 10,000 ppm, preferably 30 to 5,
000 ppm, particularly preferably 50 to 2,000 ppm
And the reaction temperature is preferably room temperature to 170.
° C, more preferably 40 to 150 ° C, particularly preferably 6
It is good to carry out in the range of 0 to 130 ° C. Further, as a catalyst, tetrabutylammonium bromide, a quaternary ammonium salt such as trimethylbenzylammonium chloride,
A tertiary amine such as triethylamine may be added.

When the glycidyl group of glycidyl (meth) acrylate is subjected to the ring-opening addition to the carboxyl group in the above-mentioned copolymer, a suitable acid value can be obtained by leaving a part of the carboxyl group. The cycloadduct becomes alkali-soluble. When the acid value becomes too small and the alkali solubility decreases, the acid value can be increased by ring-opening addition of an acid anhydride to the secondary hydroxyl group generated in the above reaction.

As the base polymer of the first resin composition of the present invention, the total amount is 100 parts by weight, 20 to 40 parts by weight of (meth) acrylic acid, 40 to 75 parts by weight of (meth) acrylic acid ester, The balance is a vinyl monomer such as styrene or acrylonitrile, or N-phenylmaleimide, etc., and the carboxyl group derived from (meth) acrylic acid is 30
It is preferable that about 70% is modified with glycicyl (meth) acrylate. If the amount of (meth) acrylic acid exceeds 40 parts by weight, the alkali solubility will be too high, and if it is less than 20 parts by weight, the alkali solubility will decrease and the pattern resolution will decrease. It is preferable to copolymerize 5 to 20 parts by weight of styrene with the base polymer. If the amount of styrene exceeds 20 parts by weight, the resin layer becomes hard and cracks easily, and if it is less than 5 parts by weight, it is difficult to obtain heat resistance. Adjustment of Tg (glass transition temperature) by the amount of (meth) acrylic acid ester,
The resin flowability and alkali solubility can be adjusted, and the above range is the optimum range.

As the base polymer of the second resin composition of the present invention, the total amount is 100 parts by weight, 20 to 40 parts by weight of (meth) acrylic acid, 40 to 75 parts by weight of (meth) acrylic acid ester, and the balance. Is a vinyl monomer such as styrene or acrylonitrile, or N-phenylmaleimide, and has 20 to 20% of the carboxyl group derived from (meth) acrylic acid.
It is preferable that 40% of the amount is modified with glycicyl (meth) acrylate.

The base polymer of the first resin composition of the present invention has a molecular weight (polystyrene conversion weight average molecular weight by gel permeation chromatography) of 20,
It is preferably in the range of 000 to 200,000, more preferably 40,000 to 150,000. If the molecular weight is too small, the fluidity due to heating becomes too large,
If the molecular weight becomes too large, the alkali solubility will deteriorate. Further, the base polymer constituting the second resin composition preferably has a molecular weight of 1,000 to 50,000, more preferably 5,000 to 30,000. If the molecular weight is too small, heat resistance, water resistance, etc. deteriorate, and if it is too large, fluidity due to heating becomes too small. In any case, the molecular weight of the base polymer of the second resin composition needs to be smaller than the molecular weight of the base polymer of the first resin composition.

The acid value of the base polymer constituting the first and second resin compositions of the present invention is 0.2 to 10.0.
The range of meq / g is preferable, and more preferably 0.4 to
5.0 meq / g, particularly preferably 0.6 to 3.0 m
eq / g. If the acid value is too small, the alkali solubility will be poor, and if it is too large, the water resistance will be poor.

In the first and second resin compositions of the present invention, it is preferable to use a polymerizable compound having at least one terminal ethylene group and / or a thermosetting resin as a crosslinking agent. As the former, a (meth) acrylic compound or an epoxy compound can be used. Examples thereof include 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, and 2-hydroxypropyl acrylate as monofunctional compounds; urethane acrylate, 1,3-butanediol diacrylate, and 1,4-difunctional compounds.
Butanediol diacrylate, 1,6-hexanediol diacrylate, diethylene glycol diacrylate, neopentyl glycol diacrylate, polyethylene glycol diacrylate, hydroxypivalate neopentyl glycol diacrylate; trimethylolpropane triacrylate as a polyfunctional compound , Pentaerythritol triacrylate, dipentaerythritol hexaacrylate, triallyl isocyanurate, and the like, and these can be used in an oligomer state. Urethane resin as thermosetting resin,
Epoxy resins, unsaturated polyester resins, alkyd resins and the like can be mentioned.

As a reaction initiator for curing active energy rays such as ultraviolet rays and electron rays, benzoin ether type benzyl, benzoin, benzoin alkyl ether, 1-
Hydroxycyclohexyl phenyl ketone; benzyl dialkyl ketal as a ketal system; 2,2′-dialicoxyacetophenone, 2-hydroxyacetophenone, pt-butyltrichloroacetophenone, pt-butyldichloroacetophenone as an acetophenone system; benzophenone as a benzophenone system , 4-chlorobenzophenone, 4,4'-dichlorobenzophenone, 4,4'-bisdimethylaminobenzophenone, o
-Methyl benzoylbenzoate, 3,3'-dimethyl-4
-Methoxybenzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, dibenzosuberone, benzyl dimethyl ketal; thioxanthone type thioxanthone, 2-chlorothioxanthone, 2-alkylthioxanthone, 2,4-dialkylthioxanthone, 2-alkylanthraquinone, 2,2'-dichloro-4-phenoxyacetone and the like are included, and the amount thereof is 0.5 to 100 parts by weight of the solid content of the base polymer and the crosslinking agent (hereinafter referred to as "resin solid content"). 10 parts by weight is preferred. If the amount is less than 0.5 parts by weight, the reaction will not be sufficiently initiated,
If it exceeds 10 parts by weight, the resin layer becomes brittle.

As a sensitizer at the time of curing of active energy rays such as ultraviolet rays and electron beams, Nisso Cure EPA, EMA, IAMA, EHMA, MABP manufactured by Shin Nisso Kako Co., Ltd.
Kayakyu EPA, D manufactured by Nippon Kayaku Co., Ltd. such as EABP
Ward Blenkinsop, ETX, DMBI, etc.
Quantacure EPD, BEA, EOB,
Examples thereof include DMB and the like, DABA manufactured by Osaka Organic Co., Ltd., and PAA and DAA manufactured by Daito Chemical Co., Ltd. The blending amount thereof is preferably 0.5 to 10 parts by weight with respect to 100 parts by weight of the resin solid content. When the amount is less than 0.5 part by weight, the reaction rate of the active energy ray curing does not improve. When the amount exceeds 10 parts by weight, the reaction speeds up and the shelf life is reduced. When used by electron beam irradiation, the reaction sensitizer may be omitted.

In the etching resist sheet of the present invention, the thickness of the layer of the first resin composition applied to the protective film is preferably 10 to 100 μm, and the layer of the second resin composition is preferably 20 to 60 μm. The optimum combination of thicknesses can be set depending on the accuracy, the diameter of the plated through hole, the thickness of the plated panel, etc. As the protective film, a polyester film is preferably used regardless of the type as long as the resin composition layer can be peeled off.

The method for manufacturing a multilayer printed wiring board using the etching resist sheet of the present invention comprises, for example, the following steps. That is, the etching resist sheet of the present invention is heat-laminated on a plated panel made of an insulating substrate having plated through holes and the entire surface is plated, and the plated through holes are filled with the second resin composition, and The step of covering the entire panel surface with a layer of the first resin composition; the step of peeling the protective film; the portion of the plated through hole of the panel that is closed by the resist and the portion where the wiring pattern is formed are irradiated with active energy rays. To cure the resin composition in the exposed portion, or to irradiate active energy rays to a portion of the plated through hole except the portion closed by the resist and the portion where the wiring pattern is formed, and the resin composition in the exposed portion To make it alkali-soluble; a step of dissolving an uncured or alkali-soluble resin composition in a weak alkaline aqueous solution; exposing It consists of the combination; first second step of dissolving the resin composition in strongly alkaline aqueous solution of the layer and in the plated through-holes of the resin composition of the panel surface; the plating part etching process.

A plated panel made of an insulating substrate having a plated through-hole on the entire surface is plated with a through-hole, for example, by drilling or laser processing on the insulating substrate.
A blind via hole is provided, and the entire surface of the panel, the through hole, and the blind via hole are plated by electroless copper plating, electrolytic copper plating, or the like.

To form an etching resist on the panel using an etching resist sheet, 60 to 12 is used.
A metal roll or a rubber roll heated to 0 ° C. may be laminated at a roll pressure of 2 to 5 kg / cm ² . When laminated by applying heat as described above, the layer of the second resin composition has a large fluidity due to heating, and therefore enters the plated through hole. On the other hand, the first resin composition is
Since the fluidity during heating is small, the surface of the panel can remain smooth. By the way, the second resin composition,
Not all of them go into the plated through holes, but some of them may remain on the surface of the panel. The etching resist sheet may be laminated on both sides at the same time, but it is preferable to laminate the etching resist sheet on each side in order to prevent bubbles in the layer of the second resin composition which has flowed into the plated through holes.

After laminating the etching resist,
Although exposure and development are performed, in this case, the protective film may be left as it is for exposure, but it is preferable to peel off the protective film and then perform exposure because the resolution is improved.

That is, in the etching resist sheet of the present invention, since the layer of the first resin composition generally has a large molecular weight and a small fluidity due to heat, and also has a low tackiness, the protective film is peeled off. Since the resin composition rarely adheres to the glass or film phototool for exposing the wiring pattern later, it is not necessary to place the phototool on the protective film for exposure as in the conventional dry film, and the phototool can be directly exposed. Since it can be placed, the exposure leakage from the gap of the protective film is eliminated, so that the pattern forming accuracy is remarkably improved. First
Since the thickness of the resin composition layer can be reduced, it is possible to form a higher density pattern.

The exposure is preferably carried out by irradiating ultraviolet rays through a photo tool. In the case of a negative resist, the portion cured by irradiation becomes slightly soluble in a weak alkaline aqueous solution such as sodium carbonate, and the unexposed portion is dissolved and removed with a weak alkaline aqueous solution. At this time, an etching resist is formed so as to close the portion where the wiring pattern of the panel is formed and the plated through hole portion. In the case of a positive type resist, the exposed part becomes soluble in weak alkali, so after irradiating ultraviolet rays to the part where the wiring pattern of the panel is formed and the part except the plating through hole that is blocked by the resist, the exposed part is weakly alkaline aqueous solution. Dissolve and remove. As described above, it is preferable to use a negative resist because of its low price, high sensitivity to active energy rays, and ease of development.

Next, etching is performed using a known copper etching solution. The plating through hole portion has the second resin composition penetrating into the hole and the first resin composition blocking the surface, so that the etching solution is used. Will not enter the hole and corrode the plating in the hole, and the plated through hole will remain in a predetermined shape.

Then, with a strong alkaline aqueous solution such as sodium hydroxide, the second resin composition layer in the plated through holes and the first resin composition layer remaining on the panel surface and the second resin composition layer are formed. By peeling off the layers, a printed wiring board having plated through holes is obtained.

[0037]

When the above etching resist is laminated on a printed wiring board having a plated through hole with a hot roll, the second resin composition layer flows into the plated through hole because it has high fluidity due to heating. By controlling the specifications of the printed wiring board and the thickness of the resin layer, the plated through holes can be almost completely filled. On the other hand, since the first resin composition layer has a low fluidity due to heating, an etching resist layer having a uniform thickness and a smooth surface is formed on the surface of the plated through hole.

[0038]

【Example】

Example 1 (Synthesis example 1 of base polymer) 40 parts by weight of n-butyl methacrylate, 15 parts by weight of methyl methacrylate, 10 parts by weight of hydroxyethyl methacrylate, 25 parts by weight of methacrylic acid and 1 part by weight of azobisisobutylnitrile. Was added dropwise to 120 parts by weight of propylene glycol monomethyl ether kept at 80 ° C. in a nitrogen gas atmosphere over 5 hours. Then, after aging for 1 hour,
Further, 0.5 part by weight of azobisisobutylnitrile was added and aged for 2 hours to synthesize a carboxyl group-containing methacrylic resin. Next, while blowing in air, 15 parts by weight of glycidyl methacrylate, 1.5 parts by weight of tetrabutylammonium bromide, and 0.15 parts by weight of hydroquinone as a polymerization inhibitor were added to the mixture at a temperature of 80 ° C.
Reaction for 8 hours at a molecular weight of 50,000 to 70,000
0, acid value 1.2 meq / g, unsaturated equivalent 1.14 mol /
A base polymer having kg of carboxyl groups was synthesized.

Synthesis Example 2 of Base Polymer A mixture of 50 parts by weight of n-butyl methacrylate, 9 parts by weight of hydroxyethyl methacrylate, 32.5 parts by weight of methacrylic acid and 2 parts by weight of azobisisobutylnitrile was added,
It was added dropwise to 120 parts by weight of propylene glycol monomethyl ether kept at 90 ° C. in a nitrogen gas atmosphere over 5 hours. Thereafter, after aging for 1 hour, 1 part by weight of azobisisobutylnitrile was further added and aging was performed for 2 hours to synthesize a carboxyl group-containing methacrylic resin. Next, while blowing in air, glycidyl methacrylate 1
5 parts by weight, tetrabutylammonium bromide 1.5
In addition, 0.1 part by weight of hydroquinone as a polymerization inhibitor
5 parts by weight was added and reacted at a temperature of 80 ° C. for 8 hours to have a molecular weight of 20,000 to 25,000 and an acid value of 2.0 meq / g.
A base polymer having a carboxyl group with an unsaturated equivalent of 1.14 mol / kg was synthesized.

(Preparation of First Resin Composition) 60 parts by weight of the base polymer of Synthesis Example 1 prepared as described above and 20 parts of pentaerythritol triacrylate (Aronix M-305 manufactured by Toagosei Co., Ltd.) as a crosslinking agent. 20 parts by weight and urethane acrylate (Aronix M-1600 manufactured by Toagosei Co., Ltd.), 5 parts by weight of active energy ray curing reaction initiator, 2 parts by weight of active energy ray curing sensitizer, and 1 part by weight of methylene blue as a pigment. It mixed well and prepared the 1st resin composition.

(Preparation of Second Resin Composition) 60 parts by weight of the base resin of Synthesis Example 2 prepared as described above, 20 parts by weight of Aronix M-305 and 20 parts by weight of Aronix M-1600 as crosslinking agents, Active energy ray curing reaction initiator 5 parts by weight, active energy ray curing sensitizer 2
The second resin composition was prepared by thoroughly mixing 1 part by weight of methylene blue as a pigment and 1 part by weight of methylene blue.

(Preparation of etching resist sheet) 16
The first resin composition was applied on a μm thick polyester film by a bar coater and dried in an atmosphere of 80 ° C. for 5 minutes to form a 10 μm layer of the first resin composition. Subsequently, the above-mentioned second resin composition was applied onto the layer of the first resin composition with a bar coater and dried in an atmosphere of 80 ° C. for 5 minutes to form a layer of the second resin composition of 40 μm. Thus, a roll-shaped etching resist sheet was prepared.

A method of manufacturing a printed wiring board using the etching resist sheet of the present invention will be described with reference to the drawings.
1 to 6 are schematic cross-sectional views for explaining a manufacturing process and a structure of a multilayer printed wiring board according to an embodiment of the present invention.

ANSI grade FR with a plate thickness of 0.8 mm-
After the glass epoxy copper clad laminate of No. 4 is drilled, the above etching resist sheet is rolled at 80 ° C. on a plated panel 5 having a plated through hole 7 and a whole surface plated by a well-known copper plating method. At a temperature of 3 kg / cm ² and a feed rate of 1.0 m / min, the metal roll 8 was used to laminate each side (FIGS. 1 and 2), and the second resin composition 3 was embedded in the plated through holes. An etching resist layer could be formed on both sides of the plated panel 5 (Fig. 3).

After peeling off the protective film 1, 200 mJ / cm ² was applied to the surface of the panel through a pattern film.
By exposing it to 1% sodium carbonate solution (Fig. 4), etching the exposed copper (Fig. 5), and peeling the film with 2% sodium hydroxide solution at 40 ° C (Fig. 6). A dense printed wiring board was obtained. Since the pattern film can be brought into direct contact with the layer of the first resin composition at the time of exposure, a pattern resolution as high as 30 to 40 μm can be obtained, but since the resin layer is tack-free, the pattern film can be easily peeled off after exposure. I was able to.

[0046]

EFFECTS OF THE INVENTION The patterning accuracy is high because it has a surface smoothness which cannot be obtained by the conventional etching resist, the thickness of the etching resist can be made as thin as possible, and the exposure can be performed without a protective film. In addition, since it is possible to fill the plating through-hole with the etching resist only by the laminating process and to form the etching resist on the surface at the same time, it is possible to manufacture a printed wiring board with excellent mass productivity, which has an extremely high industrial value. Is.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a step of laminating a first surface in a process of manufacturing a printed wiring board using the etching resist sheet of the present invention.

FIG. 2 is a schematic cross-sectional view of a step of laminating on the second surface in the manufacturing process.

FIG. 3 is a schematic cross-sectional view showing a plated panel after being laminated with an etching resist sheet in the same manufacturing process.

FIG. 4 is a schematic cross-sectional view showing the panel after forming a pattern of an etching resist by exposure and development in the same manufacturing process.

FIG. 5 is a schematic cross-sectional view showing the panel after etching copper in the same manufacturing process.

FIG. 6 is a schematic cross-sectional view showing the panel after the etching resist is peeled off in the manufacturing process.

[Explanation of symbols]

 1 Protective Film 2 Layer of First Resin Composition 3 Layer of Second Resin Composition 4 Plated Copper 5 Plated Panel 6 Insulating Substrate 7 Plated Through Hole 8 Metal Roll

Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical indication location H05K 3/42 B 7511-4E (72) Inventor Hideki Hiraoka 1 East Toa, 1 Funami-cho, Minato-ku, Aichi Prefecture Synthetic Co., Ltd. Nagoya Research Institute

Claims (3)

[Claims] 1. A first protective film which is soluble in alkali, has low fluidity when heated, and is sensitive to active energy rays.
An etching resist sheet comprising a layer of the resin composition described above, and a second resin composition layer which is soluble in alkali and has a high fluidity when heated and is sensitive to active energy rays. 2. The first and second resin compositions are polymers containing acrylic acid and / or methacrylic acid and acrylic acid ester and / or methacrylic acid ester as main components, and the acrylic resin which is a constitutional unit thereof. A linear polymer obtained by adding an ethylenically unsaturated compound having a glycidyl group to a part of a carboxyl group derived from an acid and / or methacrylic acid is used as a base polymer, and a crosslinking agent and an active energy ray curing reaction initiator are added to the base polymer. And the active energy ray curing sensitizer, and the first resin composition has a molecular weight of 2 for each base polymer.
The etching resist sheet is characterized in that the second resin composition is 10,000 to 20,000, and the second resin composition is 1,000 to 50,000 and smaller than the first resin composition. 3. A plated panel comprising an insulating substrate having plated through-holes and having the entire surface plated,
Alternatively, a step of heating and laminating the etching resist sheet according to 2, filling the plated through holes with a second resin composition, and covering the entire panel surface with a layer of the first resin composition; peeling the protective film. Step of irradiating the resin composition of the exposed portion by irradiating active energy rays to the portion of the plated through hole of the panel closed by the resist and the portion where the wiring pattern is formed, or the resist of the plated through hole The step of irradiating the resin composition in the exposed portion with an alkali by irradiating an active energy ray to the portion except the portion to be closed with and the portion to form the wiring pattern; the uncured or alkali-soluble resin composition with a weak alkaline aqueous solution. A step of dissolving; a step of etching the exposed plating part; a layer of the first resin composition on the panel surface and a plating strip. Method for manufacturing a printed wiring board, characterized in that it consists of the combination; step of dissolving the second strong alkaline solution of the resin composition in Horu.