JP4920777B2 - Method for forming resist pattern and method for manufacturing circuit board - Google Patents

Description

The present invention relates to a process for producing a forming method and a circuit board les resist pattern.

  As a method for manufacturing a circuit board, there are a subtractive method, an additive method, a semi-additive method, and the like. The subtractive method is a method of forming a circuit by providing an etching resist layer on a circuit portion of an insulating substrate having a conductive layer provided on the surface and etching away the exposed conductive layer of the non-circuit portion. The additive method is a method in which a plating resist layer is provided on a non-circuit portion on the surface of an insulating substrate, and a conductive layer is formed on a portion corresponding to the circuit portion by an electroless plating process or the like. In the semi-additive method, a plating resist layer is provided on a non-circuit portion of an insulating substrate having a thin conductive layer on the surface, and a conductive layer is formed by electrolytic plating treatment on a portion corresponding to the circuit portion. Is removed, and then a thin conductive layer in a non-circuit portion is removed by flash etching to form a circuit.

  The etching resist layer and the plating resist layer are formed by a screen printing method, a photofabrication method having an exposure and development process using a photosensitive material, an ink jet method, or the like. When trying to produce holes with a landless or narrow land width, it is important to align holes in processes such as hole drilling, screen printing, exposure, and inkjet, especially for high-density circuit boards. For landless and narrow land width holes, very high alignment accuracy is required. As shown in FIG. 22, it is most desirable that the land has a uniform width in all directions of the hole, that is, the case where the hole and the land are concentric circles. However, if the alignment is inaccurate, FIG. As shown in the diagrams on the right of b), there is a problem that the hole and the land are not concentric.

  FIG. 23 is a schematic plan view showing the positional deviation between the hole and the land when the positional deviation of the distance X occurs in the hole having the narrow land width (a) and the wide land width (b). In FIG. 23 (b), a land having a large land width is in a state in which lands are formed around the hole. In FIG. 23 (a), in a hole having a narrow land width, the land is cut off from the hole portion, and the entire outer periphery is formed. However, there is a problem that it is impossible to form a hole in which a narrow land exists. Actually, the alignment accuracy is limited due to the accuracy of drilling, expansion / contraction of the substrate, dimensional change of the photomask for exposure, and the like. In addition, since there are many types of holes formed on the high-density circuit board and the number of holes is extremely large, it is very difficult to accurately align all the holes. Accordingly, there is a problem that a land width must be designed to be large even though a high-density circuit board requires a landless or narrow land width hole (for example, Patent Document 1).

  Solves the problem of misalignment between lands and holes caused by such alignment, and manufactures circuit boards with holes and narrow land widths required for higher circuit board density. A method of forming a resin layer and a mask layer on a first surface of a substrate having a through-hole, and supplying a resin layer removing liquid from a second surface opposite to the first surface of the substrate; There is a method for forming a resist pattern and a method for manufacturing a circuit board, including a step of removing a resin layer on a through-hole on the surface and around the through-hole (Japanese Patent Application No. 2005-336827).

  In the resist pattern forming method and the circuit board manufacturing method described above, a resin layer and a mask layer are provided on one side (referred to as a first surface) of a substrate having a through hole so as to block the through hole (FIG. 2), With the resin layer removing liquid supplied from the surface (referred to as the second surface), the resin layer on the through hole and in the periphery of the through hole is removed (FIG. 3). The resin layer removing liquid supplied from the second surface passes through the through hole, reaches the resin layer on the first surface, and dissolves and removes the resin layer on the through hole and around the through hole. The mask layer is made of a component that is insoluble in the resin layer removing liquid. Therefore, the resin layer removing liquid can accurately and selectively remove only the through hole and the peripheral part of the through hole of the resin layer. As a result, the resin layer where the substrate is exposed can be formed with very high accuracy only in the through hole and the peripheral part of the through hole, and the landless and narrow land width patterns can be easily formed in the subsequent steps.

  In the resist pattern forming method and the circuit board manufacturing method described above, a state in which the plating resist layer does not exist is formed accurately and selectively with respect to the through hole and the peripheral portion of the through hole only by a process that does not require alignment. And the land width can be controlled arbitrarily.

  Here, the resin layer is generally sprayed with an organic solvent or an aqueous alkali solution to dissolve and remove unnecessary portions. However, removal with an organic solvent is not preferable from the viewpoint of environment and economy, and the resin layer is required to use an alkali-soluble resin layer, and the resin layer removal liquid is required to use an alkaline aqueous solution.

  In the resist pattern forming method and circuit board manufacturing method described above, when through holes with different hole diameters are mixed in the substrate, if an ordinary low concentration alkaline aqueous solution such as an aqueous sodium carbonate solution is used, the alkaline aqueous solution passes through the through holes. When the alkali-soluble resin layer on the through-holes and the periphery of the through-holes is dissolved and removed, the dissolution is excessively promoted as the hole diameter increases. Erosion of the soluble resin layer is increased. As shown in FIG. 24, when the pore diameter is small, the width of the alkali-soluble resin layer to be dissolved and removed is small, but there is a problem that as the pore diameter increases, the side etch increases and the dissolution and removal width widens. The erosion of the alkali-soluble resin layer due to the side etching occurs more remarkably when the volume of the portion through which the alkaline aqueous solution passes is large, such as the through hole of the circuit board. On the other hand, in order to minimize the variation in the dissolution and removal width of the alkali-soluble resin layer, for example, if the treatment time with an alkaline aqueous solution is shortened, the dissolution of the alkali-soluble resin layer tends to be insufficient and development residues are likely to occur, resulting in poor etching. Cause plating defects. Originally, it is preferable to set the land width smaller for higher density and higher definition, but there are problems of misalignment such as drilling drilling precision, expansion / contraction of the substrate, and dimensional change of the photomask. It is necessary to provide a certain fixed width. As described above, when through holes with different hole diameters are mixed in the substrate, if the land width varies depending on the hole diameter, short defects frequently occur on the substrate pattern due to the large land. There is.

JP 07-007265 A

Of the present invention challenges, regardless of the magnitude of the diameter of the through hole of the circuit board, side etching amount is unchanged, it is possible to form a resist pattern having a uniform uniform dissolution removed width Relais resist pattern A forming method and a manufacturing method of a circuit board are provided.

As a result of intensive studies to solve the above problems, the present inventors have
(1) an alkali metal carbonate from the second surface opposite to the step and the first surface of the substrate to form the alkali-soluble resin layer and a mask layer on the first surface of the substrate having a transmural hole, alkali metal phosphates An alkali-soluble resin layer treatment solution comprising at least one of inorganic alkaline compounds selected from alkali metal hydroxides and alkali metal silicates, wherein the content of the inorganic alkaline compound is 5 to 20% by mass. A method for forming a resist pattern, comprising: supplying an alkali-soluble resin layer removing solution, and then removing the alkali-soluble resin layer on the through-holes on the first surface and around the through-holes.
( 2 ) The resist pattern according to the above ( 1 ), wherein the alkali-soluble resin layer treatment solution contains 0.05 to 0.8 mol / L of at least one of sulfate and sulfite. Forming method.
( 3 ) The method for forming a resist pattern as described in ( 1 ) or ( 2 ) above, wherein the alkali-soluble resin is a photocrosslinkable resin.
( 4 ) (a) a step of preparing an insulating substrate having a first conductive layer on a first surface of the insulating substrate having a through hole, a second surface opposite to the first surface, and an inner wall of the through hole;
(B) forming a photocrosslinkable resin layer and a mask layer on the first surface, and covering the first conductive layer and the through hole opening on the first surface with the photocrosslinkable resin layer and the mask layer;
(C) including at least one of inorganic alkali compounds selected from alkali metal carbonates, alkali metal phosphates, alkali metal hydroxides, and alkali metal silicates from the second surface, The alkali-soluble resin layer treatment liquid having a content of 5 to 20% by mass is supplied, and then the alkali-soluble resin layer removing liquid is supplied, and the photocrosslinkable resin layer on the through holes on the first surface and in the periphery of the through holes Removing the first conductive layer around the through hole on the first surface,
(D) pattern exposing the photocrosslinkable resin layer on the first surface;
(E) forming a photocrosslinkable resin layer and a mask layer on the second surface, and covering the first conductive layer and the through hole opening on the second surface with the photocrosslinkable resin layer and the mask layer;
(F) removing the mask layer on the first surface;
(G) including at least one of inorganic alkaline compounds selected from alkali metal carbonates, alkali metal phosphates, alkali metal hydroxides, and alkali metal silicates from the first surface, An alkali-soluble resin layer treatment liquid having a content of 5 to 20% by mass is supplied, and then an alkali-soluble resin layer removal liquid is supplied, and the uncured photocrosslinkable resin layer on the first surface and the through-holes on the second surface Removing the photocrosslinkable resin layer on the upper and peripheral portions of the through hole, and exposing the first conductive layer on the first surface and the first conductive layer on the peripheral portion of the through hole on the second surface;
(H) pattern exposing the photocrosslinkable resin layer on the second surface;
(I) removing the mask layer on the second surface;
(J) supplying an uncured photocrosslinkable resin layer developer from the second surface, removing the uncured photocrosslinkable resin layer on the second surface, and exposing the first conductive layer on the second surface;
(K) forming a second conductive layer by electrolytic plating on the inner wall of the through hole and the periphery of the through hole, and the first conductive layer exposed on the first surface and the second surface;
(L) removing the cured photocrosslinkable resin layer on the first surface and the second surface to expose the first conductive layer on the first surface and the second surface;
(M) A method of manufacturing a circuit board, which includes a step of removing the exposed first conductive layer by flash etching in this order.
( 5 ) The step (g) includes (g1) supplying an uncured photocrosslinkable resin layer developer from the first surface, removing the uncured photocrosslinkable resin layer on the first surface, and on the first surface. A step of exposing the first conductive layer; and (g2) at least one of inorganic alkaline compounds selected from alkali metal carbonates, alkali metal phosphates, alkali metal hydroxides, and alkali metal silicates from the first surface. Supplying an alkali-soluble resin layer treatment liquid containing one kind and having an inorganic alkaline compound content of 5 to 20% by mass, then supplying an alkali-soluble resin layer removal liquid, The step of removing the photocrosslinkable resin layer around the through-hole and exposing the first conductive layer around the through-hole on the second surface, and the step (e) includes the steps (g1) and (g2). The method for producing a circuit board according to ( 4 ), which is performed between the two.
( 6 ) The above-mentioned ( 4 ) or ( 5 ), wherein the alkali-soluble resin layer treatment liquid contains 0.05 to 0.8 mol / L of at least one of sulfate and sulfite. Circuit board manufacturing method.
I found.

  In the resist pattern forming method and circuit board manufacturing method, when a low concentration alkaline aqueous solution is used for developing a resist material used for etching, plating, sandblasting, etc., a polymer containing a carboxyl group or the like soluble in the alkaline aqueous solution A compound having a surfactant function such as a binder is used for the alkali-soluble resin layer, and micelles are formed in an aqueous alkali solution and finely dispersed in an emulsion state, whereby the alkali-soluble resin layer is dissolved and diffused. When the alkali-soluble resin layer is a photocrosslinkable resin layer, a compound having a surfactant function, such as a polymer binder containing a carboxyl group that is soluble in an alkaline aqueous solution, is used, and a photopolymerizable unsaturated compound or A micelle mainly having undissolved components such as a photopolymerization initiator is formed to dissolve and diffuse the photocrosslinkable resin layer. In such a dissolution phenomenon, when a low concentration alkaline aqueous solution is used, if through holes with different hole diameters are mixed in the substrate, the alkaline aqueous solution reaches the alkali-soluble resin layer through the through holes, and on and around the through holes. When the portion of the alkali-soluble resin layer is dissolved and removed, the larger the pore size, the more the dissolution is accelerated and the side etching is more likely to proceed. The alkali-soluble resin layer treatment liquid of the present invention is a high-concentration aqueous alkali solution having an inorganic alkaline compound concentration of 5 to 20% by mass. When a high-concentration alkaline aqueous solution is used, the side-etching caused by the wraparound of the processing solution can be suppressed while the alkali-soluble resin layer component that has been micellized in the course of dissolution and removal is once insolubilized and prevented from being dissolved and diffused. That is, excessive dissolution of the alkali-soluble resin layer is suppressed, and the dissolution / removal width can be made uniform.

Sectional drawing showing 1 process of the formation method of the resist pattern concerning this invention. Sectional drawing showing 1 process of the formation method of the resist pattern concerning this invention. Sectional drawing showing 1 process of the formation method of the resist pattern concerning this invention. Sectional drawing showing 1 process of the manufacturing method of the circuit board concerning this invention. Sectional drawing showing 1 process of the manufacturing method of the circuit board concerning this invention. Sectional drawing showing 1 process of the manufacturing method of the circuit board concerning this invention. Sectional drawing showing 1 process of the manufacturing method of the circuit board concerning this invention. Sectional drawing showing 1 process of the manufacturing method of the circuit board concerning this invention. Sectional drawing showing 1 process of the manufacturing method of the circuit board concerning this invention. Sectional drawing showing 1 process of the manufacturing method of the circuit board concerning this invention. Sectional drawing showing 1 process of the manufacturing method of the circuit board concerning this invention. Sectional drawing showing 1 process of the manufacturing method of the circuit board concerning this invention. Sectional drawing showing 1 process of the manufacturing method of the circuit board concerning this invention. Sectional drawing showing 1 process of the manufacturing method of the circuit board concerning this invention. Sectional drawing showing 1 process of the manufacturing method of the circuit board concerning this invention. Sectional drawing showing 1 process of the manufacturing method of the circuit board concerning this invention. Sectional drawing showing 1 process of the manufacturing method of the circuit board concerning this invention. Sectional drawing showing 1 process of the manufacturing method of the circuit board concerning this invention. Sectional drawing which shows the through-hole diameter at the time of drilling in the formation method of the resist pattern concerning this invention, the through-hole diameter at the time of plating, and the diameter of an alkali-soluble resin layer removal part. Sectional drawing which shows the through-hole diameter at the time of drilling in the manufacturing method of the circuit board concerning this invention, the through-hole diameter at the time of plating, and the diameter of a photocrosslinkable resin layer removal part. Sectional drawing which shows the hole land part of the circuit board concerning this invention. Schematic showing holes and lands. The schematic diagram showing the position gap of a hole and a land. Schematic showing the hole diameter and land width.

  Hereinafter, the alkali-soluble resin layer removing method, the resist pattern forming method, and the circuit board manufacturing method will be described in detail.

  The alkali-soluble resin layer treatment liquid (I) of the present invention comprises an alkali metal carbonate such as lithium, sodium or potassium carbonate or bicarbonate, an alkali metal phosphate such as potassium or sodium phosphate, lithium, It contains at least one of inorganic alkali compounds selected from alkali metal hydroxides such as sodium or potassium hydroxide and alkali metal silicates such as potassium and sodium silicates. Among these, particularly preferable compounds include alkali metal carbonates.

  The alkali-soluble resin layer treatment liquid (I) of the present invention contains the inorganic alkaline compound in an amount of 5 to 20% by mass, more preferably 6 to 18% by mass, and even more preferably 7.5 to 15% by mass with respect to the treatment liquid. . If it is less than 5% by mass, the micelles are difficult to be insolubilized, and the micelles solubilized during dissolution and removal tend to dissolve and diffuse. On the other hand, if it exceeds 20% by mass, precipitation tends to occur and the liquid tends to be unstable over time and workability. In particular, when developing a photocrosslinkable resin layer, if a high concentration aqueous alkali solution is used, the cured photocrosslinkable resin layer tends to swell. Swelling of the cured photocrosslinkable resin layer is not preferred because it causes a decrease in adhesion to the substrate and resolution. When the alkali-soluble resin layer treatment liquid is an aqueous solution, the pH of the solution is preferably in the range of 9-12. In addition, a small amount of a surfactant, an antifoaming agent and the like can be mixed as appropriate.

  More preferably, it contains at least one of sulfate and sulfite as in the alkali-soluble resin layer treatment liquid (II) of the present invention. Examples of the sulfates or sulfites include alkali metal sulfates or sulfites such as lithium, sodium or potassium, and alkaline earth metal sulfates or sulfites such as magnesium and calcium. Of these, alkali metal sulfates or sulfites are particularly preferably used. Sulfate ion or sulfite ion contained in sulfate or sulfite is a polyvalent anion having a large liquid separation permutation and has a large salting-out effect. In the circuit board manufacturing method (8) of the present invention, in the step (g), the uncured photocrosslinkable resin layer is removed in a state where the uncured photocrosslinkable resin layer and the cured photocrosslinkable resin layer coexist. In this step (g), the cured photocrosslinkable resin layer must not be dissolved or swollen in the alkali-soluble resin layer treatment solution. In the alkali-soluble resin layer treatment liquid (II) of the present invention, a polyanion having a large liquid separation permutation is added to cause hydration by salting out, thereby suppressing dissolution and swelling of the cured photocrosslinkable resin layer. Can do.

  In the alkali-soluble resin layer treatment liquid (II) of the present invention, at least one of the above sulfates or sulfites is 0.05 to 0.8 mol / L, more preferably 0.1 to 0.6 mol / L. L, more preferably 0.15 to 0.4 mol / L. If it is less than 0.05 mol / L, the salting-out power is weak and the degree of hydration is low, so that when the photocrosslinkable resin layer is developed, the cured photocrosslinkable resin layer tends to swell. On the other hand, if it exceeds 0.8 mol / L, excessive hydration occurs and dissolution / diffusion of micelles is inhibited, so that poor dissolution tends to occur.

  The solvent in the alkali-soluble resin layer treatment liquids (I) to (II) of the present invention is not particularly limited as long as it can stably disperse and dissolve the above components, but water is preferably used. Examples of water include industrial water, tap water, ion exchange water, and distilled water. In addition, an appropriate amount of an organic solvent may be contained in order to further stabilize the above components or to adjust the dissolution and removal rate.

  The alkali-soluble resin according to the present invention may be any polymer that is soluble in an alkaline aqueous solution. For example, an acrylic resin, a methacrylic resin, a styrene resin, an epoxy resin, an amide resin, an amide epoxy resin, Examples thereof include organic polymers such as alkyd resins and phenol resins. Among these, it is preferable that it is a thing obtained by superposing | polymerizing (radical polymerization etc.) the monomer (polymerizable monomer) which has an ethylenically unsaturated double bond. In view of alkali developability, an acrylic resin or a methacrylic resin is preferable. These polymers soluble in an alkaline aqueous solution may be used alone or in combination of two or more. Examples of such a monomer having an ethylenically unsaturated double bond include styrene; vinyl toluene, α-methyl styrene, p-methyl styrene, p-ethyl styrene, p-methoxy styrene, p-ethoxy styrene. Styrene derivatives such as p-chlorostyrene and p-bromostyrene; acrylamide such as diacetone acrylamide; acrylonitrile; esters of vinyl alcohol such as vinyl-n-butyl ether; (meth) acrylic acid alkyl ester; (meth) acrylic acid Tetrahydrofurfuryl ester, (meth) acrylic acid dimethylaminoethyl ester, (meth) acrylic acid diethylaminoethyl ester, (meth) acrylic acid glycidyl ester, 2,2,2-trifluoroethyl (meth) acrylate, 2,2, 3,3-te Rafluoropropyl (meth) acrylate, (meth) acrylic acid, α-bromo (meth) acrylic acid, α-chloro (meth) acrylic acid, β-furyl (meth) acrylic acid, β-styryl (meth) acrylic acid, etc. (Meth) acrylic acid monoesters; maleic monomers such as maleic acid, maleic anhydride, monomethyl maleate, monoethyl maleate, monoisopropyl maleate; fumaric acid, cinnamic acid, α-cyanocinnamic acid , Itaconic acid, crotonic acid, propiolic acid and the like.

Examples of the (meth) acrylic acid alkyl ester include the following general formula (I):
^{_{CH 2 = C (R 1)}} -COOR 2 (I)
[In Formula (I), R ¹ represents a hydrogen atom or a methyl group, and R ² represents an alkyl group having 1 to 12 carbon atoms. ]
And compounds in which a hydroxyl group, an epoxy group, a halogen atom, or the like is substituted on the alkyl group of these compounds. Examples of the alkyl group having 1 to 12 carbon atoms represented by R ² in the general formula (I) include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group. Group, nonyl group, decyl group, undecyl group, dodecyl group, and structural isomers thereof.

  The alkali-soluble resin according to the present invention preferably contains a carboxyl group in consideration of solubility in an alkaline aqueous solution. Therefore, the polymerizable monomer having a carboxyl group and other polymerizable monomer are radically polymerized. Examples of the polymerizable monomer having a carboxyl group include (meth) acrylic acid, vinylbenzoic acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, crotonic acid, cinnamic acid, and acrylic acid dimer. be able to. Of these, (meth) acrylic acid is most preferred. The (meth) acrylic acid content in the polymer soluble in the alkaline aqueous solution is preferably 25% by mass or more in terms of the monomer composition ratio.

  The polymer soluble in the aqueous alkali solution that can be used for the alkali-soluble resin according to the present invention can be used alone or in combination of two or more. Examples of the combination of polymers soluble in an alkaline aqueous solution when two or more types are used in combination include, for example, combinations of polymers soluble in two or more alkaline aqueous solutions having different copolymerization components, and different weight average molecular weights. Examples include combinations of polymers soluble in two or more types of alkaline aqueous solutions, and combinations of polymers soluble in two or more types of alkaline aqueous solutions having different dispersities (weight average molecular weight / number average molecular weight).

  The weight average molecular weight of the alkali-soluble resin according to the present invention is preferably 10,000 to 300,000, and more preferably 10,000 to 150,000. If the weight average molecular weight is less than 10,000, the flexibility of the resin tends to decrease. Moreover, when developing a photocrosslinkable resin layer using aqueous alkali solution, there exists a tendency for the adhesiveness of a hardening photocrosslinkable resin layer to fall. On the other hand, when the weight average molecular weight exceeds 300,000, the formed micelles are difficult to dissolve and diffuse in the alkaline aqueous solution, and the treatment time tends to be long.

  The acid value of the alkali-soluble resin according to the present invention is preferably 30 to 300 mgKOH / g. When the acid value is less than 30 mgKOH / g, it is difficult to stably form solubilized micelles, and the solubility tends to be remarkably lowered. On the other hand, if it exceeds 300 mgKOH / g, the glass transition temperature of the resin becomes high, and a higher temperature is required for heat melting. Moreover, there exists a tendency for the flexibility of resin to fall. Furthermore, when developing a photocrosslinkable resin layer using aqueous alkali solution, there exists a tendency for the adhesiveness of a hardening photocrosslinkable resin layer to fall.

  The alkali-soluble resin according to the present invention may contain components other than the polymer soluble in the aqueous alkali solution as necessary. Examples of such components include plasticizers such as dibutyl phthalate, polyethylene glycol, and p-toluenesulfonamide added to control film physical properties, dyes such as malachite green added to improve visibility, other pigments, Examples include fillers, antifoaming agents, flame retardants, stabilizers, adhesion-imparting agents, leveling agents, peeling accelerators, antioxidants, fragrances, imaging agents, thermal crosslinking agents, and the like. About 0.01 to 20 parts by mass can be contained per 100 parts by mass of the combined body. Such components can be used alone or in combination of two or more. In addition, the alkali-soluble resin of the present invention can be used, if necessary, alcohols such as methanol, ethanol, n-propanol, 2-butanol and n-hexanol; ketones such as acetone and 2-butanone; ethyl acetate and butyl acetate. , Esters such as acetic acid-n-amyl, methyl sulfate, ethyl propionate, dimethyl phthalate, ethyl benzoate, aromatic hydrocarbons such as toluene, xylene, benzene, ethylbenzene; tetrahydrofuran, diethyl ether, ethylene glycol monomethyl ether , Ethylene glycol monoethyl ether, ethers such as 1-methoxy-2-propanol, solvents such as N, N-dimethylformamide, dimethyl sulfoxide or mixed solvents thereof, and a solution having a solid content of about 30 to 60% by mass As, applying It can be.

  The alkali-soluble resin according to the present invention is used in the form of a so-called dry film having an alkali-soluble resin layer formed on a carrier film and, optionally, a protective film on the alkali-soluble resin layer.

  As the carrier film, a polymer film having heat resistance and solvent resistance such as polyethylene terephthalate, polypropylene, polyethylene, and polyester is preferably used. The thickness of the carrier film is preferably 5 to 25 μm, more preferably 8 to 20 μm, and particularly preferably 10 to 16 μm. When the thickness of the carrier film is less than 5 μm, the carrier film itself may be broken when the carrier film is peeled off. Moreover, when the thickness of a carrier film exceeds 25 micrometers, there exists a tendency for the resolution to fall. Furthermore, the haze (based on JIS K 7105) of the carrier film is preferably 0.001 to 5.0, more preferably 0.001 to 2.0, and 0.01 to 1.8. It is particularly preferred. When this haze exceeds 2.0, the resolution tends to decrease.

  The thickness of the alkali-soluble resin layer is preferably 1 to 100 μm, more preferably 5 to 50 μm, after drying. If the thickness is less than 1 μm, it tends to be difficult to apply industrially, whereas if it exceeds 100 μm, the adhesion to the substrate tends to decrease.

  After dissolving the alkali-soluble resin according to the present invention in the solvent to obtain a solution having a solid content of about 30 to 60% by mass, the solution is applied on a support and dried to obtain a dry film. As the coating method, known methods such as a roll coater, a comma coater, a gravure coater, an air knife coater, a die coater, and a bar coater can be employed. Moreover, a drying process can be performed at 70-150 degreeC, for about 5 to 30 minutes, for example.

  As the protective film, polymer films such as polyethylene terephthalate, polypropylene, polyethylene, and polyester are preferably used. The thickness of such a protective film is preferably 5 to 30 μm, more preferably 10 to 28 μm, and particularly preferably 15 to 25 μm. When the thickness is less than 5 μm, the protective film tends to be easily broken during lamination. On the other hand, when the thickness exceeds 30 μm, the cost tends to be inferior.

  Moreover, since the protective film and the carrier film must be removable from the alkali-soluble resin layer later, it is preferable that the protective film and the carrier film are not subjected to a surface treatment that makes removal impossible. However, surface treatment such as corona discharge treatment may be performed as necessary. Moreover, the carrier film and the protective film may be subjected to antistatic treatment as necessary.

  The alkali-soluble resin according to the present invention may be a photocrosslinkable resin. The basic composition of the photocrosslinkable resin is (A) a binder polymer, (B) a photopolymerizable compound having at least one polymerizable ethylenically unsaturated bond in the molecule (hereinafter referred to as a photopolymerizable compound), ( C) Photopolymerization initiator.

  The (A) binder polymer that can be used in the photocrosslinkable resin according to the present invention may be a polymer that is soluble in an alkaline aqueous solution, and may be the same as the alkali-soluble resin described above.

  The photopolymerizable compound (B) relating to the photocrosslinkable resin according to the present invention may be any photopolymerizable compound having at least one polymerizable ethylenically unsaturated bond in the molecule. For example, a compound obtained by reacting a polyhydric alcohol with an α, β-unsaturated carboxylic acid; a bisphenol A (meth) acrylate compound; obtained by reacting a glycidyl group-containing compound with an α, β-unsaturated carboxylic acid Compound; Urethane monomer such as (meth) acrylate compound having urethane bond in molecule; Nonylphenoxypolyethyleneoxyacrylate; γ-chloro-β-hydroxypropyl-β ′-(meth) acryloyloxyethyl-o-phthalate, β- Examples thereof include phthalic acid compounds such as hydroxyalkyl-β '-(meth) acryloyloxyalkyl-o-phthalate; and (meth) acrylic acid alkyl esters. These photopolymerizable compounds can be used alone or in combination of two or more.

  Examples of the photopolymerization initiator (C) related to the photocrosslinkable resin according to the present invention include benzophenone, N, N′-tetramethyl-4,4′-diaminobenzophenone (Michler ketone), N, N′-tetraethyl-4, 4'-diaminobenzophenone, 4-methoxy-4'-dimethylaminobenzophenone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, 2-methyl-1- [4- (methylthio ) Phenyl] -2-morpholino-propanone-1 and the like; 2-ethylanthraquinone, phenanthrenequinone, 2-tert-butylanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, 2,3-benzanthraquinone, 2-phenylanthraquinone, 2,3-diphenylanthra Quinones such as nonone, 1-chloroanthraquinone, 2-methylanthraquinone, 1,4-naphthoquinone, 9,10-phenanthraquinone, 2-methyl-1,4-naphthoquinone, 2,3-dimethylanthraquinone; benzoin methyl ether Benzoin ether compounds such as benzoin ethyl ether and benzoin phenyl ether; benzoin compounds such as benzoin, methyl benzoin and ethyl benzoin; benzyl derivatives such as benzyl dimethyl ketal; 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer 2- (o-chlorophenyl) -4,5-di (methoxyphenyl) imidazole dimer, 2- (o-fluorophenyl) -4,5-diphenylimidazole dimer, 2- (o-methoxyphenyl) ) -4,5-Difeni 2,4,5-triarylimidazole dimers such as imidazole dimer, 2- (p-methoxyphenyl) -4,5-diphenylimidazole dimer; 9-phenylacridine, 1,7-bis (9 , 9'-acridinyl) heptane and the like; N-phenylglycine, N-phenylglycine derivatives, coumarin compounds and the like. The substituents of the aryl groups of two 2,4,5-triarylimidazoles in the 2,4,5-triarylimidazole dimer are the same and may give the target compound. Asymmetric compounds may be provided. Moreover, you may combine a thioxanthone type compound and a tertiary amine compound like the combination of diethyl thioxanthone and dimethylaminobenzoic acid. These may be used alone or in combination of two or more.

  In the photocrosslinkable resin according to the present invention, the blending amount of the (A) binder polymer is preferably 40 to 80% by mass in the total amount of the (A) component and the (B) component, and is 45 to 70% by mass. It is more preferable. When the blending amount of the component (A) is less than 40% by mass, the mechanical strength of the photocrosslinked portion is lowered. Moreover, there exists a problem that film property worsens. When it exceeds 80 mass%, photopolymerizability will fall.

  (B) It is preferable that the compounding quantity of a photopolymerizable compound is 20-60 mass% in the total amount of (A) component and (B) component, and it is more preferable that it is 30-55 mass%. If such a blending amount is less than 20% by mass, the photopolymerizability tends to be insufficient, whereas if it exceeds 60% by mass, the photocrosslinked product tends to become brittle. In addition, when the said bisphenol A type | system | group (meth) acrylate compound contains in (B) component, it is preferable that the compounding quantity is 3-90 mass% in the said (B) component, 5-70 mass%. It is more preferable that When the blending amount of the bisphenol A-based (meth) acrylate compound is less than 3% by mass in the component (B), the resolution tends to be inferior. On the other hand, when it exceeds 90% by mass, the peeling time of the cured photocrosslinkable resin layer is long. Tend to be longer.

  Furthermore, it is preferable that the compounding quantity of (C) component is 0.1-20 mass parts with respect to 100 mass parts of mixture of (A) component and (B) component, and is 0.2-10 mass parts. More preferably. If the blending amount is less than 0.1 parts by mass, the photopolymerizability becomes insufficient. On the other hand, if it exceeds 20 parts by mass, the absorption on the surface of the composition increases during exposure and the internal photocrosslinking tends to be insufficient.

  The photocrosslinkable resin according to the present invention may contain components other than the above-described components (A) to (C) as necessary. Examples of such components include dyes such as malachite green, photochromic agents such as tribromophenyl sulfone and leuco crystal violet, thermochromic inhibitors, plasticizers such as p-toluenesulfonamide, pigments, fillers and antifoaming agents. , Flame retardants, stabilizers, adhesion-imparting agents, leveling agents, peeling accelerators, antioxidants, fragrances, imaging agents, thermal crosslinking agents, etc., and 100 parts by mass of a mixture of component (A) and component (B) Each can be contained in an amount of about 0.01 to 20 parts by mass. Such components can be used alone or in combination of two or more.

  The photo-crosslinkable resin according to the present invention may be used, if necessary, alcohols such as methanol, ethanol, n-propanol, 2-butanol and n-hexanol; ketones such as acetone and 2-butanone; ethyl acetate and butyl acetate. , Esters such as acetic acid-n-amyl, methyl sulfate, ethyl propionate, dimethyl phthalate, ethyl benzoate, aromatic hydrocarbons such as toluene, xylene, benzene, ethylbenzene; tetrahydrofuran, diethyl ether, ethylene glycol monomethyl ether , Ethylene glycol monoethyl ether, ethers such as 1-methoxy-2-propanol, solvents such as N, N-dimethylformamide, dimethyl sulfoxide or mixed solvents thereof, and a solution having a solid content of about 30 to 60% by mass Can be applied as .

  The photocrosslinkable resin according to the present invention is a so-called dry film resist having a photocrosslinkable resin layer formed on a carrier film in the same manner as the alkali-soluble resin, and a protective film on the photocrosslinkable resin layer. Used in. As the dry film resist, a commercially available one can be used.

  In the present invention, the processing method for dissolving and removing the alkali-soluble resin layer includes a dip method, a battle method, a spray method, brushing, scraping, etc., and the high-pressure spray method is for improving the resin layer removability and removing the residue. Is the most suitable. Moreover, you may use together 2 or more types of removal methods as needed.

  In the present invention, the treatment conditions (temperature, spray pressure, time) for dissolving and removing the alkali-soluble resin layer are appropriately adjusted according to the micelle formation and dissolution and removability of the alkali-soluble resin layer. Specifically, processing temperature is 10-50 degreeC, More preferably, it is 15-40 degreeC, More preferably, it is 15-35 degreeC. The spray pressure is preferably 0.05 to 0.5 MPa, more preferably 0.1 to 0.3 MPa.

Subsequently, sequentially applies will be described the processing steps of the alkali-soluble resin layer is removed how the present invention. The alkali-soluble resin layer removal method in the present invention comprises at least two treatment steps. In the treatment step (α), the alkali-soluble resin layer formed by supplying an excessively high-concentration alkali-soluble resin layer treatment solution. The micelle is insolubilized to prevent dissolution and diffusion in the processing solution. Next, in the treatment step (β) performed after the treatment step (α), an alkali-soluble resin layer removing solution is supplied, and the micelles insolubilized in the treatment step (α) are redispersed and dissolved and removed.

Oite the alkali-soluble resin layer is removed how the present invention, the alkali-soluble The resin layer-removing liquid, water or alkali metal carbonates, alkali metal phosphates, alkali metal hydroxides, alkali metal silicates, tetramethyl An aqueous solution having a concentration of 3% by mass or less among ammonium hydroxide and monoethanolamine can be used. Among these, water or an aqueous solution containing 3% by mass or less of an alkali metal carbonate can be particularly preferably used. By treating with water or a low-concentration alkali-soluble resin layer removing solution, the redispersibility of the insolubilized micelles is improved and rapid treatment becomes possible. When the concentration of the alkali metal carbonate exceeds 3% by mass, it is difficult to redisperse the insolubilized micelles and the treatment time tends to be long, which is not preferable.

In the resist pattern forming method ( 1 ) of the present invention, the alkali-soluble resin layer 5 and the mask layer 4 are provided so as to block the through hole on one surface (first surface) of the substrate having the through hole of the insulating substrate 1. (FIG. 2 (a)), supplying the alkali-soluble resin layer treatment liquid of the present invention from the surface opposite to the first surface (referred to as the second surface), and then supplying the alkali-soluble resin layer removal liquid of the present invention. Then, the alkali-soluble resin layer 5 on the through hole on the first surface and around the through hole is removed (FIG. 3A). The same applies when the conductive layer 2 is present only on the surface of the insulating substrate 1 (FIG. 2B), and when the conductive layer 2 is present on the surface of the insulating substrate 1 and the inner wall of the hole (FIG. 2C). In the step, the alkali-soluble resin layer on the through-hole on the first surface and around the through-hole is removed (FIGS. 3B and 3C).

In the circuit board manufacturing method ( 4 ) of the present invention, a circuit board is manufactured by a semi-additive method. This will be described in detail with reference to FIGS.

  First, the through hole 3 is formed in the insulating substrate 1 (FIG. 4) (FIG. 5). Next, the first conductive layer 6 is provided on the surface of the insulating substrate 1 and the inner wall of the through hole 3 (FIG. 6). Thereafter, the photocrosslinkable resin layer 8 is provided on the first surface so as to be tented in the through hole (FIG. 7). At that time, the mask layer 4 is formed on the photocrosslinkable resin layer 8 so as to be in contact with the photocrosslinkable resin layer 8. Next, the alkali-soluble resin layer treatment liquid of the present invention is supplied from the second surface opposite to the first surface, and then the alkali-soluble resin layer removal liquid is supplied to the first surface on the through-holes and the periphery of the through-holes. The photocrosslinkable resin layer 8 is dissolved and removed (FIG. 8). Photocrosslinkability on and around the through hole by adjusting the conditions of the removal process such as the type and concentration of the removal liquid, the time and temperature of the removal process, and the spray pressure and discharge rate of the removal liquid in the case of spraying. The removal amount of the resin layer 8 can be adjusted, and the exposed width of the first conductive layer can be controlled. Therefore, it is possible to control the land width thereafter from the landless to the narrow land and the wide land. If necessary, drying is performed, and then pattern exposure is performed on the photocrosslinkable resin layer 8 on the first surface (FIG. 9).

  The photocrosslinkable resin layer 8 and the mask layer 4 are also formed on the second surface by the same method as that applied to the first surface (FIG. 10). After removing the mask layer 4 on the first surface (FIG. 11), the treatment with the alkali-soluble resin layer treatment liquid and the alkali-soluble resin layer removal liquid is performed again. At least the alkali-soluble resin layer treatment liquid of the present invention is supplied from at least the first surface, and then the alkali-soluble resin layer removing liquid is supplied to dissolve and remove the uncured photocrosslinkable resin layer 8 on the surface of the first surface. Through the hole, the photocrosslinkable resin layer 8 on the through hole on the second surface and around the through hole is dissolved and removed (FIG. 12). At this time, similarly to the treatment of the first surface, the removal amount of the photocrosslinkable resin layer 8 on the through hole of the second surface and the peripheral portion of the through hole can be adjusted, and the exposed width of the first conductive layer 6 can be adjusted. Can be controlled. If necessary, drying is performed, and then pattern exposure is performed on the photocrosslinkable resin layer 8 on the second surface to cure the photocrosslinkable resin in the non-circuit portion (FIG. 13).

  After removing the mask layer 4 on the second surface that has been subjected to pattern exposure (FIG. 14), a treatment with an uncured photocrosslinkable resin layer developer is performed. The developer is supplied at least from the second surface, and the uncured photocrosslinkable resin layer 8 on the surface of the second surface is dissolved and removed (FIG. 15).

  Thereby, a resist pattern made of the cured photocrosslinkable resin 9 functioning as a plating resist layer can be formed on both the first surface and the second surface. Next, the second conductive layer 7 is formed on the exposed first conductive layer 6 by electrolytic plating (FIG. 16), and then the cured photocrosslinkable resin layer 9 on the first and second surfaces is removed ( 17) and flash etching the first conductive layer 6 that is exposed, a circuit board having a landless or narrow land width can be manufactured (FIG. 18).

  As the insulating substrate according to the present invention, a paper substrate phenol resin or glass substrate epoxy resin substrate, a polyester film, a polyimide film, a liquid crystal polymer film, or the like can be used. As the conductive layer, copper, silver, gold, aluminum, stainless steel, 42 alloy, nichrome, tungsten, ITO, conductive polymer, various metal complexes, and the like can be used. Examples of these are described in “Handbook of Printed Circuit Technology” (edited by Japan Printed Circuit Industry Association, Nikkan Kogyo Shimbun, 1987).

  As a method of providing the first conductive layer on the insulating substrate according to the present invention, a sputtering method, a vapor deposition method, an electroless plating method, a method of attaching an ultrathin conductive layer such as a metal foil to the insulating substrate, For example, there is a method of forming a thin film by etching the conductive layer of the laminated laminate. After the through hole is formed in the insulating substrate, the first conductive layer can be provided on the surface of the insulating substrate and the inner wall of the through hole, or after the first conductive layer is provided on the surface of the insulating substrate, the through hole is formed. You may open a hole and provide a 1st conductive layer in the surface and the inner wall of a through-hole again. The second conductive layer can be formed by an electrolytic plating method for the first conductive layer.

  For the electroless plating treatment and the electrolytic plating treatment according to the present invention, for example, those described in "Handbook of Printed Circuit Technology" (edited by Japan Printed Circuit Industry Association, Nikkan Kogyo Shimbun, 1987) should be used. Can do.

  Pattern exposure is performed by laser direct drawing, contact exposure through a photomask, proximity exposure, projection exposure, or the like. As the light source, in addition to various laser light sources, an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a metal halide lamp, a xenon lamp, or the like can be used. By this pattern exposure, the photocrosslinkable resin in the non-circuit portion is cured.

  If the removal of the mask layer on the first surface is after the step of removing the photocrosslinkable resin layer on the through hole on the first surface and in the periphery of the through hole, the photocrosslinkable resin layer and the mask layer on the second surface are removed. You may carry out before formation. If there is a possibility of damage or contamination of the first surface during the formation of the photocrosslinkable resin layer and the mask layer on the second surface, the first after the formation of the photocrosslinkable resin layer and the mask layer on the second surface. It is preferable to remove the mask layer on the surface because the first surface after pattern exposure can be protected by the mask layer. On the other hand, after supplying the alkali-soluble resin layer removing liquid from the first surface, the mask layer is removed, and then drying, exposure, and the like can be performed. Further, after removing the uncured photocrosslinkable resin layer on the first surface, the photocrosslinkable resin layer and the mask layer on the second surface are formed, and then on the through holes on the second surface and the periphery of the through holes. The photocrosslinkable resin layer may be removed. Thereby, the removal process of the photocrosslinkable resin layer on the through holes on the first surface and the second surface and around the through holes is exactly the same. That is, since the amount of the photocrosslinkable resin layer to be removed is small, the running property of the liquid is improved and the land width uniformity is also improved.

  The uncured photocrosslinkable resin layer developer is a developer for removing the uncured photocrosslinkable resin layer when an uncured portion and a cured portion are present in the photocrosslinkable resin layer. The alkali-soluble resin layer treatment liquid and the removing liquid of the present invention can be used in the treatment and removal of the uncured portion of the photocrosslinkable resin layer in the photocrosslinkable resin layer in which no cured portion is present. The purpose and action are essentially different from those of the functional resin layer developer. A conventionally well-known thing can be used as a non-hardened photocrosslinkable resin layer developing solution, and low concentration solutions, such as 0.3-3 mass% sodium carbonate, potassium carbonate, sodium hydroxide, are used suitably. The pH of the uncured photocrosslinkable resin layer developer is preferably in the range of 9 to 12, and the temperature is adjusted according to the dissolution and removal of the alkali-soluble resin layer. In addition, a small amount of a surfactant, an antifoaming agent and the like can be mixed as appropriate.

  In the method for producing a circuit board of the present invention, examples of a method for removing the cured photocrosslinkable resin layer used as the plating resist layer include a method for removing with a high pH alkaline aqueous solution, an organic solvent, and the like.

  The etchant used for flash etching of the first conductive layer according to the present invention may be any solution that can dissolve and remove the first conductive layer 6. For example, common etching solutions such as alkaline ammonia, sulfuric acid-hydrogen peroxide, cupric chloride, persulfate, and ferric chloride can be used. Moreover, as an apparatus and a method, apparatuses and methods, such as horizontal spray etching and immersion etching, can be used, for example. These details are described in “Printed Circuit Technology Handbook” (edited by Japan Printed Circuit Industry Association, Nikkan Kogyo Shimbun, 1987).

  Hereinafter, the present invention will be described in more detail by way of examples. However, the present invention is not limited to these examples.

Example 1
Hole diameter of 0.1mmφ, 0.2mmφ, 0.3mmφ, 0.5mmφ, 1.0mmφ, 3.0mmφ, 5.0mmφ on glass base epoxy resin substrate (area 340mm × 510mm, base material thickness 0.1mm) After drilling through holes with different drilling machines, desmear treatment is performed, followed by electroless copper plating, and an electroless copper plating layer with a thickness of about 0.5 μm is formed on the surface including the inner walls of the through holes. It provided as a 1st conductive layer. Here, with respect to the respective hole diameters, the through holes are produced by changing only the drill diameter, and the thickness of the copper plating layer is not changed. Using a laminator for dry film resist, an alkali-soluble resin film composed of an alkali-soluble resin (film thickness 25 μm) shown in Table 1 and a 12 μm mask layer (support film, material: polyester) is used as one side of the substrate (first And an alkali-soluble resin layer and a mask layer (support film).

  Next, using the alkali-soluble resin layer treatment liquid (22 ° C.) shown in Table 2, shower spray was applied for 30 seconds at a spray pressure of 0.2 MPa from the second surface side of the substrate, and on the through hole on the first surface. And the micelle of the alkali-soluble resin layer around the through hole was insolubilized. At this time, when the dissolution and diffusion of the alkali-soluble resin layer was visually observed, no dissolution was observed, and it was confirmed that the micelles of the alkali-soluble resin layer were insoluble.

  Then, using the alkali crosslinkable resin layer removing liquid (30 ° C.) described in Table 2, shower spray was applied for 10 seconds at a spray pressure of 0.2 MPa from the second surface side of the substrate, and through holes on the first surface The insolubilized micelles of the alkali-soluble resin layer on the top and the periphery of the through hole were solubilized again and dissolved and removed. When the through hole and the peripheral part of the through hole having different hole diameters were observed with an optical microscope, the alkali-soluble resin layer in the peripheral part of the through hole was removed concentrically with the through hole. In addition, the diameter L3 of the alkali-soluble resin layer removal portion with respect to the different diameter through holes from the minimum 0.1 mmφ to the maximum 5.0 mmφ tended to increase as the hole diameter increased, but the minimum hole diameter 0.1 mmφ And the difference in the diameter of the alkali-soluble resin layer removal portion between the maximum pore diameter of 5.0 mmφ was minimized to 18 μm. The results are shown in Table 5. The various parameters for the through-holes shown in FIG. 19 are as follows: through-hole diameter L1 (= through-hole drill diameter) at the time of drilling, through-hole diameter L2 (= L1-1 μm) at the time of plating, diameter of the alkali-soluble resin layer removal portion L3.

(Examples 2 to 15)
Except for Example 11 and Example 12, the alkali-soluble resin layer treatment liquid described in Example 1 was replaced with the alkali-soluble resin layer treatment liquid described in Table 2, and Examples 11 and 12 were described in Example 1. The alkali-soluble resin layer on the through hole and the periphery of the through hole was removed by the same method as in Example 1 except that the alkali-soluble resin layer removing liquid was changed to the alkali-soluble resin layer removing liquid shown in Table 2. Here, with respect to the respective hole diameters, the through holes are produced by changing only the drill diameter, and the thickness of the copper plating layer is not changed. When the through hole and the peripheral part of the through hole having different hole diameters were observed with an optical microscope, the alkali-soluble resin layer in the peripheral part of the through hole was removed concentrically with the through hole. Table 5 shows the difference in the diameter of the alkali-soluble resin layer removal portion between the minimum hole diameter of 0.1 mmφ and the maximum hole diameter of 5.0 mmφ.

(Example 16)
Hole diameter of 0.1mmφ, 0.2mmφ, 0.3mmφ, 0.5mmφ, 1.0mmφ, 3.0mmφ, 5.0mmφ on glass base epoxy resin substrate (area 340mm × 510mm, base material thickness 0.1mm) After drilling through holes with different drilling machines, desmear treatment is performed, followed by electroless copper plating, and an electroless copper plating layer with a thickness of about 0.5 μm is formed on the surface including the inner walls of the through holes. It provided as a 1st conductive layer. Here, with respect to the respective hole diameters, the through holes are produced by changing only the drill diameter, and the thickness of the copper plating layer is not changed. Using a laminator for dry film resist, Nichigo-Morton Co., Ltd. dry film photoresist (Alfo NIT225 (dry film thickness: 25 μm)) is thermocompression bonded to one side (first side) of the substrate to form a photocrosslinkable resin layer And a mask layer (support film) was provided.

  Next, using the alkali-soluble resin layer treatment liquid (22 ° C.) for the first surface listed in Table 3, shower spray was applied for 60 seconds from the second surface side of the substrate at a spray pressure of 0.2 MPa, The micelles of the photocrosslinkable resin layer on the through holes and in the periphery of the through holes were made insoluble. At this time, when the dissolution and diffusion of the photocrosslinkable resin layer was visually observed, no dissolution was observed and it was confirmed that the micelles of the photocrosslinkable resin layer were insoluble.

  Subsequently, using the alkali crosslinkable resin layer removing liquid (30 ° C.) shown in Table 4, shower spray was applied for 30 seconds at a spray pressure of 0.2 MPa from the second surface side of the substrate, and the first surface through-hole was formed. The insolubilized micelles of the photocrosslinkable resin layer on the top and the periphery of the through hole were solubilized again and dissolved and removed. When the through hole and the peripheral part of the through hole having different diameters were observed with an optical microscope, the photocrosslinkable resin layer in the peripheral part of the through hole was removed concentrically with the through hole. In addition, the diameter L6 of the photocrosslinkable resin layer removal portion for the different diameter through-holes having a minimum diameter of 0.1 mm to a maximum of 5.0 mmφ tended to increase as the hole diameter increased. The difference in the diameter of the photocrosslinkable resin layer removal portion between 1 mmφ and the maximum hole diameter of 5.0 mmφ was minimized to 14 μm. The results are shown in Table 6. Various parameters for the through hole shown in FIG. 20 are as follows: the through hole diameter L4 (= through hole drill diameter) at the time of drilling, the through hole diameter L5 (= L4-1 μm) at the time of plating, and the photocrosslinkable resin layer removal portion. The diameter is L6.

  A photomask (conductor width and gap: 35 μm) on which a circuit pattern is drawn is placed on the first surface of the substrate, and a high pressure mercury lamp light source device for baking (Unirec URM300, manufactured by USHIO) is used for 30 seconds with ultraviolet light. Pattern exposure was performed.

  Next, using the dry film resist laminator on the second surface of the substrate after the exposure processing, the same dry film photoresist for circuit formation as the first surface is thermocompression-bonded, and the photocrosslinkable resin layer and the mask layer Was established. Thereafter, the mask layer on the first surface was peeled off and removed.

  Next, using the alkali-soluble resin layer treatment liquid (22 ° C.) for the second surface described in Table 3, shower spray was applied for 30 seconds from the first surface side of the substrate at a spray pressure of 0.2 MPa, The uncured portion of the photocrosslinkable resin layer and the micelles of the photocrosslinkable resin layer on the through hole on the second surface and in the periphery of the through hole were insolubilized. At this time, when the dissolution and diffusion of the uncured portion of the photocrosslinkable resin layer on the first surface and the photocrosslinkable resin layer on the through hole on the second surface and in the periphery of the through hole were visually observed, dissolution was not observed at all. It was confirmed that the micelles of the photocrosslinkable resin layer were insolubilized.

  Subsequently, using the alkali-soluble resin layer removing liquid (30 ° C.) shown in Table 4, a shower spray was applied for 10 seconds at a spray pressure of 0.2 MPa from the first surface side of the substrate, and the photocrosslinkability of the first surface The uncured portion of the resin layer and the insolubilized micelles of the photocrosslinkable resin layer on and around the through holes on the second surface were again solubilized and dissolved and removed. When the through hole and the peripheral part of the through hole having different hole diameters on the second surface were observed with an optical microscope, the photocrosslinkable resin layer in the peripheral part of the through hole was removed concentrically with the through hole. In addition, the diameter L6 of the photocrosslinkable resin layer removal portion for the different diameter through-holes having a minimum diameter of 0.1 mm to a maximum of 5.0 mmφ tended to increase as the hole diameter increased. The difference in the diameter of the photocrosslinkable resin layer removal portion between 1 mmφ and the maximum pore diameter of 5.0 mmφ was suppressed to a minimum of 11 μm. Furthermore, no swelling was observed in the cured photocrosslinkable resin layer on the first surface.

  A photomask (conductor width and gap: 35 μm) on which a circuit pattern is drawn is placed on the second surface of the substrate, and a high pressure mercury lamp light source device for baking (Unirec URM300, manufactured by USHIO) is used for 30 seconds with ultraviolet light. Pattern exposure was performed. Thereafter, the mask layer on the second surface was peeled off and removed.

  Next, using a 1% by mass sodium carbonate aqueous solution (30 ° C.), a shower spray was applied for 30 seconds from the second surface side of the substrate at a spray pressure of 0.2 MPa, and the photocrosslinkable resin layer portion on the second surface Was removed.

  As a result of observing the resist pattern composed of the cured photocrosslinkable resin layer on the first surface and the second surface, the resist pattern is formed so that the first conductive layer is accurately exposed concentrically around the through hole and the through hole periphery. Thus, the resist pattern on the substrate surface was not swelled and was well formed.

  Next, electrolytic copper plating was performed to form an electrolytic copper plating layer having a thickness of about 12 μm on the first conductive layer as the second conductive layer. Then, it processed with 3 mass% sodium hydroxide aqueous solution, and peeled and removed the bridge | crosslinking part of the photocrosslinkable resin used as a plating resist layer.

  Furthermore, it processed with the sulfuric acid-hydrogen peroxide type etching liquid (Mitsubishi Gas Chemical make, product name CPE, 30 degreeC, spray pressure 0.2MPa), and the exposed 1st conductive layer was removed. When the obtained circuit board was observed with an optical microscope, the lands in the through holes having different hole diameters were concentrically formed with the through holes. Further, the difference in the land diameter with respect to the different diameter through-holes from the minimum 0.1 mmφ to the maximum 5.0 mmφ was suppressed to 20 μm or less, and the land diameters at the respective hole diameters on the first surface and the second surface were hardly changed. . No disconnection was observed in the obtained circuit board, and a circuit board having a uniform land width could be produced even when through holes having different hole diameters were mixed in the board. Table 6 shows the measurement results of the land diameter L9 having a hole diameter of 0.10 mmφ on the first surface and the second surface. Various parameters for the through-hole shown in FIG. 21 are as follows: through-hole diameter L7 (= through-hole drill diameter) at the time of drilling, through-hole diameter L8 (L7-24 μm) after flash etching, land diameter L9 on the first surface, The land diameter L10 of the two surfaces.

(Examples 17 to 30)
A circuit board was produced in the same manner as in Example 16 except that the alkali-soluble resin layer treatment liquid on the second surface described in Example 16 was replaced with the alkali-soluble resin layer treatment liquid described in Table 3. Here, with respect to the respective hole diameters, the through holes are produced by changing only the drill diameter, and the thickness of the copper plating layer is not changed. When the through hole just before electrolytic copper plating and the peripheral part of the through hole were observed with an optical microscope on each of the first and second surfaces, the photocrosslinkable resin layer on the peripheral part of the through hole was removed concentrically with the through hole. It was. Further, the difference in the diameter of the photocrosslinkable resin layer removal portion with respect to the different diameter through holes from the minimum 0.1 mmφ to the maximum 5.0 mmφ was suppressed to 20 μm or less. In Example 23, since the sulfite ion concentration was low and the salting-out effect by the polyvalent anion was not sufficient, the second surface was photocrosslinked by applying shower spray from the first surface side of the substrate at a spray pressure of 0.2 MPa for 60 seconds. When the uncured portion of the curable resin layer and the photocrosslinkable resin layer on the through hole on the second surface and the periphery of the through hole were removed, partial swelling was observed in the cured photocrosslinkable resin layer on the first surface. . In Example 24, since the sulfite ion concentration was high and the salting-out effect by the polyvalent anion was excessive, shower spray was applied from the first surface side of the substrate at a spray pressure of 0.2 MPa for 60 seconds to form a through hole on the second surface. When removing the photocrosslinkable resin layer on the upper part and the periphery of the through hole, film shrinkage of the photocrosslinkable resin layer on the second surface progressed, and the dissolution removal width was reduced. That is, in Example 23 and Example 24, the difference generate | occur | produced in the diameter of the photocrosslinkable resin layer removal part in each hole diameter of the 1st surface and the 2nd surface. In other examples, swelling of the cured photocrosslinkable resin layer on the first surface and reduction in dissolution and removal width due to film shrinkage of the photocrosslinkable resin layer on the second surface were not observed. Table 6 shows the difference in the diameter of the photocrosslinkable resin layer removing portion between the minimum hole diameter of 0.1 mmφ and the maximum hole diameter of 5.0 mmφ on each of the first surface and the second surface.

  When the same processing as in Example 16 was performed and the circuit board obtained after the flash etching processing was observed with an optical microscope, the lands were removed concentrically with the through holes. Further, the difference in land diameter with respect to through holes having different diameters from a minimum of 0.1 mmφ to a maximum of 5.0 mmφ was suppressed to 20 μm or less. In the examples other than Example 23 and Example 24, the land diameters in the respective hole diameters of the first surface and the second surface were hardly changed. In Example 23 and Example 24, there was a difference of 20 μm or more in the land diameters in the respective hole diameters of the first surface and the second surface, but no disconnection was seen in the circuit boards obtained in all Examples, and the substrate Even when through holes having different hole diameters were mixed, a circuit board having a uniform land width could be produced. Table 6 shows the measurement results of the land diameter L9 having a hole diameter of 0.10 mmφ on the first surface and the second surface.

(Example 31)
In Example 16, a circuit-forming dry film photoresist identical to the first surface is thermocompression-bonded to the second surface of the substrate on which the first surface exposure processing has been completed using a dry film resist laminator. Before providing the crosslinkable resin layer and the mask layer, the first surface of the substrate on which the first surface exposure processing was completed using a 1% by mass sodium carbonate aqueous solution (30 ° C.) as an uncured photocrosslinkable resin layer developer. Shower spray is applied for 30 seconds from the surface side with a spray pressure of 0.2 MPa to dissolve and remove the uncured photocrosslinkable resin layer on the first surface, and then, on the second surface of the substrate using a laminator for dry film resist The same dry film photoresist for circuit formation as the first surface is thermocompression-bonded, a photocrosslinkable resin layer and a mask layer are provided, the mask layer on the second surface is peeled off, and then removed from the first surface to Table 3 Second described Using the alkali-soluble resin layer treatment liquid (22 ° C.), shower spray was applied for 30 seconds at a spray pressure of 0.2 MPa from the first surface side of the substrate, and the light on the through holes on the second surface and the periphery of the through holes Next, the micelles of the crosslinkable resin layer were insolubilized, and then shower spray was applied for 10 seconds at a spray pressure of 0.2 MPa from the first surface side of the substrate using the alkali-soluble resin layer removing liquid (30 ° C.) shown in Table 4. Then, a circuit board was produced in the same manner as in Example 16 except that the insolubilized micelles of the photocrosslinkable resin layer on the through hole on the second surface and in the periphery of the through hole were solubilized and removed again. Here, with respect to the respective hole diameters, the through holes are produced by changing only the drill diameter, and the thickness of the copper plating layer is not changed. When the through hole just before electrolytic copper plating and the peripheral part of the through hole were observed with an optical microscope on each of the first and second surfaces, the photocrosslinkable resin layer on the peripheral part of the through hole was removed concentrically with the through hole. It was. Further, the difference in the diameter of the photocrosslinkable resin layer removal portion with respect to the different diameter through holes from the minimum 0.1 mmφ to the maximum 5.0 mmφ was suppressed to 20 μm or less. Table 6 shows the difference in the diameter of the photocrosslinkable resin layer removing portion between the minimum hole diameter of 0.1 mmφ and the maximum hole diameter of 5.0 mmφ on each of the first surface and the second surface.

  When the same processing as in Example 16 was performed and the circuit board obtained after the flash etching processing was observed with an optical microscope, the lands were removed concentrically with the through holes. Further, the difference in land diameter with respect to the different diameter through holes from the minimum 0.1 mmφ to the maximum 5.0 mmφ is suppressed to 20 μm or less, and the land diameters in the respective hole diameters of the first surface and the second surface are hardly changed, The best land uniformity was obtained. No disconnection was observed in the obtained circuit board, and a circuit board having a uniform land width could be produced even when through holes having different hole diameters were mixed in the board. Table 6 shows the measurement results of the land diameter L9 having a hole diameter of 0.10 mmφ on the first surface and the second surface.

(Comparative Examples 1-11)
The alkali-soluble resin layer treatment solution described in Example 1 is described in Table 7 as the alkali-soluble resin layer treatment solution, and Comparative Example 9 includes not only the alkali-soluble resin layer treatment solution but also the alkali-soluble resin layer removal solution in Table 6. The alkali-soluble resin layer on the through-holes and the periphery of the through-holes was removed by the same method as in Example 1 except that the alkali-soluble resin layer removing solution was replaced with the same. Here, with respect to the respective hole diameters, the through holes are produced by changing only the drill diameter, and the thickness of the copper plating layer is not changed.

  In Comparative Examples 1, 2, 4, 6, 8, and 10, photocrosslinking of the first surface on the through hole and the periphery of the through hole was performed by applying shower spray from the second surface side of the substrate at a spray pressure of 0.2 MPa for 60 seconds. When removing the photopolymerizable resin layer, the micelles of the photocrosslinkable resin layer are not insolubilized. The resin layer was dissolved and diffused. As a result, as the hole diameter of the through hole increased, specifically, when the hole diameter of the through hole became larger than 0.5 mmφ, the diameter of the photocrosslinkable resin layer removal portion expanded three times or more. Furthermore, when the hole diameter of the through-hole becomes larger than 1.0 mmφ, the photocrosslinkable resin layer around the through-hole is not removed concentrically with the through-hole, and the diameter of the photocrosslinkable resin layer removal part is measured. could not. In the circuit board after the flash etching process, short circuit defects frequently occurred.

  In Comparative Examples 3, 5, 7, 9, and 11, the concentration of the inorganic alkaline compound was excessively high, salt precipitation occurred at a liquid temperature of 22 ° C., and an aqueous solution could not be prepared at a desired concentration.

  The present invention can be used in the field of manufacturing circuit boards, semiconductor devices, etc., precision metal processing, and plasma display back plates.

DESCRIPTION OF SYMBOLS 1 Insulating board | substrate 2 Conductive layer 3 Through-hole 4 Mask layer 5 Alkali-soluble resin layer 6 1st conductive layer 7 2nd conductive layer 8 Photocrosslinkable resin layer 9 Curing part 10 Through-hole 11 Land part conductive layer 12 Hole 13 Land

Claims (6)

The step of forming the alkali-soluble resin layer and the mask layer on the first surface of the substrate having a through hole and the second surface opposite to the first surface of the substrate are alkali metal carbonate, alkali metal phosphate, alkali metal water. Supplying an alkali-soluble resin layer treatment liquid containing at least one of inorganic alkaline compounds selected from oxides and alkali metal silicates, wherein the content of the inorganic alkaline compound is 5 to 20% by mass, A method for forming a resist pattern, comprising a step of supplying an alkali-soluble resin layer removing liquid to remove the alkali-soluble resin layer on and around the through hole of the first surface. The method for forming a resist pattern according to claim 1, wherein the alkali-soluble resin layer treatment liquid contains 0.05 to 0.8 mol / L of at least one of sulfate and sulfite. 3. The method for forming a resist pattern according to claim 1, wherein the alkali-soluble resin is a photocrosslinkable resin. (A) preparing an insulating substrate having a first conductive layer on a first surface of the insulating substrate having a through hole, a second surface opposite to the first surface, and an inner wall of the through hole;
(B) forming a photocrosslinkable resin layer and a mask layer on the first surface, and covering the first conductive layer and the through hole opening on the first surface with the photocrosslinkable resin layer and the mask layer;
(C) including at least one of inorganic alkali compounds selected from alkali metal carbonates, alkali metal phosphates, alkali metal hydroxides, and alkali metal silicates from the second surface, The alkali-soluble resin layer treatment liquid having a content of 5 to 20% by mass is supplied, and then the alkali-soluble resin layer removing liquid is supplied, and the photocrosslinkable resin layer on the through holes on the first surface and in the periphery of the through holes Removing the first conductive layer around the through hole on the first surface,
(D) pattern exposing the photocrosslinkable resin layer on the first surface;
(E) forming a photocrosslinkable resin layer and a mask layer on the second surface, and covering the first conductive layer and the through hole opening on the second surface with the photocrosslinkable resin layer and the mask layer;
(F) removing the mask layer on the first surface;
(G) including at least one of inorganic alkaline compounds selected from alkali metal carbonates, alkali metal phosphates, alkali metal hydroxides, and alkali metal silicates from the first surface, An alkali-soluble resin layer treatment liquid having a content of 5 to 20% by mass is supplied, and then an alkali-soluble resin layer removal liquid is supplied, and the uncured photocrosslinkable resin layer on the first surface and the through-holes on the second surface Removing the photocrosslinkable resin layer on the upper and peripheral portions of the through hole, and exposing the first conductive layer on the first surface and the first conductive layer on the peripheral portion of the through hole on the second surface;
(H) pattern exposing the photocrosslinkable resin layer on the second surface;
(I) removing the mask layer on the second surface;
(J) supplying an uncured photocrosslinkable resin layer developer from the second surface, removing the uncured photocrosslinkable resin layer on the second surface, and exposing the first conductive layer on the second surface;
(K) forming a second conductive layer by electrolytic plating on the inner wall of the through hole and the periphery of the through hole, and the first conductive layer exposed on the first surface and the second surface;
(L) removing the cured photocrosslinkable resin layer on the first surface and the second surface to expose the first conductive layer on the first surface and the second surface;
(M) A step of removing the exposed first conductive layer by flash etching
A method of manufacturing a circuit board including the above in this order. (G) The process is (g1) supplying uncured photocrosslinkable resin layer developer from the first surface, removing the uncured photocrosslinkable resin layer on the first surface, and conducting the first conductivity on the first surface. And (g2) at least one of inorganic alkaline compounds selected from alkali metal carbonates, alkali metal phosphates, alkali metal hydroxides, and alkali metal silicates from the first surface. And supplying an alkali-soluble resin layer treatment liquid having a content of the inorganic alkaline compound of 5 to 20% by mass, and then supplying an alkali-soluble resin layer removal liquid, on the through holes on the second surface and around the through holes The step (e) is performed between the steps (g1) and (g2), and the step (e) is performed between the steps (g1) and (g2). A method for manufacturing a circuit board according to claim 4. The method for producing a circuit board according to claim 4 or 5, wherein the alkali-soluble resin layer treatment solution contains 0.05 to 0.8 mol / L of at least one of sulfate and sulfite. .

Images