TWI841340B - Non-photosensitive surface modifiers, laminates, printed circuit boards and electronic devices - Google Patents

Abstract

The non-photosensitive surface modifier of the present invention is a non-photosensitive surface modifier that forms a surface modification layer between a metal layer and a resin layer, and contains at least a heterocyclic compound having a structure of the general formula W or the general formula Y, and the concentration of the heterocyclic compound is in the range of 0.001 to 0.01 mass %. In the formula, _Rn1 and _Rn2 are alkyl groups. L is a linking group. _W1 to _W7 are carbon atoms or nitrogen atoms, at least 2 of which are nitrogen atoms, one of which is NH, and _W1 to _W7 form a condensed ring. _Y1 to _Y5 are carbon atoms or nitrogen atoms, at least 2 of which are nitrogen atoms, one of which is NH, and _Y1 to _Y5 form a heterocyclic ring. m is an integer greater than 1.

Description

Non-photosensitive surface modifiers, laminates, printed circuit boards and electronic devices

The present invention relates to a non-photosensitive surface modifier, a laminate, a printed circuit board and an electronic device, and in particular to a non-photosensitive surface modifier that can further improve the adhesion between a metal layer and a resin layer and has excellent storage stability.

In recent years, due to the progress of data society, printed wiring boards (also called "printed circuit boards") with high-density and high-precision wiring are required. In the manufacturing process of printed wiring boards, resin materials such as anti-etching agents, anti-plating agents, solder resists, and prepregs are bonded to the surface of metal layers and metal wiring. In the manufacturing process of printed wiring boards and the products after manufacturing, high adhesion is required between the metal layer and the resin layer. Therefore, in order to improve the adhesion between the metal layer and the resin layer, the following methods are known: a method of forming a coating on the surface of the metal layer to improve the adhesion with the resin layer (for example, refer to Patent Document 1), and a method of increasing the adhesion by adding sulfur-containing compounds and nitrogen-containing compounds to the photosensitive resin (for example, refer to Patent Document 2).

However, in the technologies of the above-mentioned patent documents 1 and 2, although the adhesion between the metal layer and the resin layer has been improved to a certain extent, sufficient adhesion has not yet been obtained. In particular, in recent years, with the advancement of 5G portable communications and high-density mounting technology for semiconductor packaging, there are higher requirements for the low roughness of the metal layer of the printed wiring board and the narrowing of the metal wiring, and at the same time, the adhesion between the metal layer and the resin layer is also required to be higher than before.

In addition, it is known that a method of using a treatment liquid containing a nitrogen-containing compound having an amine group to form an organic film on the metal surface to improve the adhesion between the metal and the resin is used (for example, refer to Patent Document 3). In this case, the concentration in the treatment liquid must be 0.05 mass % or more. Therefore, in the technology of Patent Document 3, the organic film becomes thicker, and because coagulation damage occurs in the organic film, the adhesion between the metal layer and the resin layer cannot achieve satisfactory adhesion, and further improvement is needed. [Prior technical literature] [Patent literature]

[Patent Document 1] Japanese Patent Publication No. 2017-203073 [Patent Document 2] Japanese Patent Publication No. 2020-34933 [Patent Document 3] Japanese Patent Publication No. 2008-274311

[The problem that the invention wants to solve]

The present invention is completed in view of the above problems and conditions, and the problem it aims to solve is to further improve the adhesion between the metal layer and the resin layer, and to provide a non-photosensitive surface modifier, laminate, printed circuit board and electronic device with excellent storage stability. [Means for solving the problem]

In order to solve the above-mentioned problem, the inventors of the present invention have studied the causes of the above-mentioned problem. In order to strengthen the interaction between the metal on the surface of the metal layer and the resin on the surface of the resin layer, they have found that as a non-photosensitive surface modifier forming a surface modification layer between the metal layer and the resin layer, a heterocyclic compound having a specific structure of an indazole or triazole structure containing a nitrogen-containing heterocyclic that interacts with the metal and an alkylamine group that interacts with the resin can be used to improve the adhesion and storage stability of the metal layer and the resin layer, thereby completing the present invention. That is, the above-mentioned problem of the present invention is solved by the following means.

1. A non-photosensitive surface modifier, which is a non-photosensitive surface modifier for forming a surface modification layer between a metal layer and a resin layer, wherein the non-photosensitive surface modifier contains at least a heterocyclic compound having a structure of the following general formula W or general formula Y, and the concentration of the heterocyclic compound is in the range of 0.001 to 0.01 mass %. [In the formula, _Rn1 and _Rn2 are alkyl groups. L is a linking group. _W1 to _W7 are carbon atoms or nitrogen atoms, at least 2 of which are nitrogen atoms, one of which is NH, and _W1 to _W7 form a condensed ring. _Y1 to _Y5 are carbon atoms or nitrogen atoms, at least 2 of which are nitrogen atoms, one of which is NH, and _Y1 to _Y5 form a heterocyclic ring. m is an integer greater than 1.]

2. The non-photosensitive surface modifier as described in item 1, wherein the heterocyclic compound has at least a structure represented by the following general formula 1, 2, 3 or 4. [In the formula, _Rn1 and _Rn2 are alkyl groups. L is a linking group. _R1 is a hydrogen atom, an alkyl group, an aryl group or a heteroaryl group, and may further have a substituent. _R2 is an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a carboxyl group, an ester group, an amide group, a heteroaryl group or a halogenated group. Each n is an integer of 0 to 4. m is an integer greater than 1. When there are multiple substituents _R2 , each substituent _R2 may be the same or different. In addition, when there are multiple n, each n may be the same or different, and further, when there are multiple m, each m may be the same or different.]

3. The non-photosensitive surface modifier as described in item 2, wherein the heterocyclic compound has the structure represented by the general formula 1.

4. The non-photosensitive surface modifier as described in item 1, wherein the heterocyclic compound has a structure represented by the following general formula 5. [In the formula, _Rn1 and _Rn2 are alkyl groups. L is a linking group. _R2 is an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a carboxyl group, an ester group, an amide group, a heteroaryl group or a halogenated group. Each n is an integer of 0 to 4. m is an integer greater than 1. When there are multiple substituents _R2 , each substituent _R2 may be the same or different.]

5. The non-photosensitive surface modifier as described in any one of items 1 to 4, which contains at least water or alcohol.

6. A laminate comprising a surface modification layer and a resin layer sequentially disposed on a metal layer, wherein the surface modification layer contains at least a heterocyclic compound having a structure represented by the following general formula 1, 2, 3 or 4. [In the formula, _Rn1 and _Rn2 are alkyl groups. L is a linking group. _R1 is a hydrogen atom, an alkyl group, an aryl group or a heteroaryl group, and may further have a substituent. _R2 is an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a carboxyl group, an ester group, an amide group, a heteroaryl group or a halogenated group. Each n is an integer of 0 to 4. m is an integer greater than 1. When there are multiple substituents _R2 , each substituent _R2 may be the same or different. In addition, when there are multiple n, each n may be the same or different, and further, when there are multiple m, each m may be the same or different.]

7. The laminate as described in item 6, wherein the heterocyclic compound has the structure represented by the general formula 1.

8. The laminate as described in item 6, wherein the heterocyclic compound has a structure represented by the following general formula 5. [In the formula, _Rn1 and _Rn2 are alkyl groups. L is a linking group. _R2 is an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a carboxyl group, an ester group, an amide group, a heteroaryl group or a halogenated group. Each n is an integer of 0 to 4. m is an integer greater than 1. When there are multiple substituents _R2 , each substituent _R2 may be the same or different.]

9. The laminate as described in item 6, wherein the resin layer is a photosensitive resin composition containing an alkali-soluble resin.

10. A printed circuit board using the multilayer body as described in any one of items 6 to 9.

11. An electronic device using the laminate as described in any one of items 6 to 9. [Effect of the invention]

By means of the above-mentioned means of the present invention, the adhesion between the metal layer and the resin layer can be further improved, and a non-photosensitive surface modifier and laminate having excellent storage stability can be provided. The manifestation mechanism or action mechanism of the effect of the present invention has not yet been clarified, but it is speculated as follows.

Since the non-photosensitive surface modifier of the present invention is a treatment liquid containing at least a heterocyclic compound having a structure represented by the general formula W or the general formula Y, the nitrogen atom (N atom) in the skeleton structure of the heterocyclic compound interacts with the metal to form a coordination bond and increase the adhesion. On the other hand, the alkylamino group can form an ionic bond by the action of the amino group and the acidic group in the resin, and can be closely bonded by an interaction force stronger than the π-π interaction and the van der Waals force. Therefore, the surface modification layer formed by such a non-photosensitive surface modifier can further enhance the adhesion of the metal layer and the resin layer by existing between the metal layer and the resin layer due to the surface modification layer having the above-mentioned interaction. Note that since the surface modification layer formed by the non-photosensitive surface modification agent is a non-photosensitive layer, when the resin layer is an anti-etching layer containing a photosensitive resin, it is estimated that even if patterning is performed by exposure, it will not be affected, and strong adhesion between the surface modification layer and the metal layer can be maintained.

Furthermore, by having an alkylamino group, in particular, by making the nitrogen atom in the skeleton structure of the aforementioned heterocyclic compound having a planar structure exist at a position almost opposite to the alkylamino group, as shown in FIG1, the molecular skeleton of the aforementioned heterocyclic compound (for example, the exemplary compound (1) in FIG1) is coordinated in the vertical direction (the thickness direction of the surface modification layer 30), the nitrogen atom (N) in the ring skeleton of the heterocyclic compound interacts with the metal of the metal layer 10, and the _alkylamino group ( _Rn2Rn1 ) can approach the resin layer 20, and it is estimated that a further strong interaction can be obtained. Note that the atoms in the schematic diagram of the exemplary compound (1) in FIG1 are the same as the atoms in the exemplary compound (1) shown in FIG2.

Furthermore, since the non-photosensitive surface modifier of the present invention is a dilute solution containing the aforementioned heterocyclic compound at a concentration in the range of 0.001 to 0.01 mass %, when used as a surface modification layer, it does not cause coagulation damage and can improve the adhesion between the metal layer and the resin layer. In addition, since the aforementioned heterocyclic compound has a tertiary alkylamine group at the end of the skeleton structure, it is less susceptible to oxidation and has better storage stability than compounds with primary and secondary alkylamine groups or compounds with aromatic amine groups introduced at the end.

The non-photosensitive surface modifier of the present invention is a non-photosensitive surface modifier that forms a surface modification layer between a metal layer and a resin layer, and contains at least a heterocyclic compound having a structure of the general formula W or the general formula Y, and the concentration of the aforementioned heterocyclic compound is in the range of 0.001 to 0.01 mass %. This feature is a technical feature common to or corresponding to each of the following embodiments.

As an embodiment of the present invention, the heterocyclic compound preferably has at least a structure represented by the aforementioned general formula 1, 2, 3 or 4, more preferably has a structure represented by the aforementioned general formula 1, and particularly preferably has a structure represented by the aforementioned general formula 5 from the viewpoint of improving the adhesion between the metal layer and the resin layer.

Furthermore, from the viewpoint of solubility, the non-photosensitive surface modifier of the present invention preferably contains at least water or alcohol.

The laminate of the present invention is a laminate having a surface modification layer and a resin layer sequentially disposed on a metal layer, wherein the surface modification layer contains at least a heterocyclic compound having a structure represented by the following general formula 1, 2, 3 or 4. Thus, a laminate having improved adhesion between the metal layer and the resin layer can be provided.

In the laminate of the present invention, the heterocyclic compound has the structure represented by the general formula 1 to improve the adhesion between the metal layer and the resin layer, and preferably has the structure represented by the general formula 5. In addition, the resin layer is preferably a photosensitive resin composition containing an alkali-soluble resin to improve the adhesion by interacting with the alkylamine group contained in the heterocyclic compound.

Furthermore, the laminate of the present invention can be applied to printed circuit boards or electronic devices.

The following describes the components of the present invention and the forms and aspects for implementing the present invention. Note that in this case, the meaning of "~" is to include the numerical values before and after it as the lower limit and upper limit.

[Non-photosensitive surface modifier] The non-photosensitive surface modifier of the present invention is a non-photosensitive surface modifier that forms a surface modification layer between a metal layer and a resin layer, and contains at least one heterocyclic compound having a structure of the general formula W or the general formula Y, and the concentration of the aforementioned heterocyclic compound is in the range of 0.001 to 0.01 mass %. Note that in the present invention, the so-called "non-photosensitive surface modifier" refers to a modifier that absorbs light under normal conditions in order to form a surface modification layer between a metal layer and a resin layer, and does not break bonds in the molecule or polymerize the molecules. It refers to a treatment solution prepared by adding the heterocyclic compound to the solvent described later.

In the above general formula W and Y, _Rn1 and _Rn2 are alkyl groups, preferably alkyl groups with 1 to 6 carbon atoms. L is a linking group. In the above general formula W, _W1 to _W7 are carbon atoms or nitrogen atoms, at least 2 of which are nitrogen atoms, one of which is NH, and _W1 to _W7 form a condensed ring. In the above general formula Y, _Y1 to _Y5 are carbon atoms or nitrogen atoms, at least 2 of which are nitrogen atoms, one of which is NH, and _Y1 to _Y5 form a heterocyclic ring. m is an integer greater than 1, and is particularly preferably an integer of 1 to 4.

In addition, the non-photosensitive surface modifier of the present invention preferably contains at least one heterocyclic compound having a structure represented by Formula 1, 2, 3 or 4.

In the above general formula 1, _Rn1 and _Rn2 are alkyl groups, preferably alkyl groups with 1 to 6 carbon atoms. L is a linking group. _R1 is a hydrogen atom, an alkyl group, an aryl group or a heteroaryl group, preferably an aryl group, and may further have a substituent. Examples of the above substituent include: an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a carboxyl group, an ester group, an amide group, a heteroaryl group or a halogen group (halogen atom). In the above general formulas 1 to 4, _R2 is an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a carboxyl group, an ester group, an amide group, a heteroaryl group or a halogen group (halogen atom); preferably an alkyl group, an aryl group, an alkoxy group or an aryloxy group. Each n is an integer of 0 to 4. m is an integer greater than 1, preferably an integer of 1 to 4. In addition, in each of the general formulae 1 to 4, when there are a plurality of substituents R ₂ , each substituent R ₂ may be the same or different from each other. In addition, when there are a plurality of n, each n may be the same or different from each other, and further, when there are a plurality of m, each m may be the same or different from each other.

Furthermore, among the heterocyclic compounds having the structures represented by the aforementioned general formulae 1 to 4, the heterocyclic compound having the structure represented by the aforementioned general formula 1 is preferred from the viewpoint of improving the adhesion between the metal layer and the resin layer through the interaction between the metal layer and the surface modified layer and between the surface modified layer and the resin layer.

Furthermore, the heterocyclic compound of the present invention preferably has a structure represented by the following general formula 5, from the viewpoint of improving the adhesion between the metal layer and the resin layer.

In the above general formula 5, _Rn1 and _Rn2 are alkyl groups, preferably alkyl groups with 1 to 6 carbon atoms. L is a linking group. _R2 is an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a carboxyl group, an ester group, an amide group, a heteroaryl group or a halogen group (halogen atom), and is particularly preferably an alkyl group, an aryl group, an alkoxy group or an aryloxy group. Each n is an integer of 0 to 4. m is an integer greater than 1, and is particularly preferably an integer of 1 to 4. When there are multiple substituents _R2 , each substituent _R2 may be the same or different from each other.

Examples of the heterocyclic compound having a structure represented by the general formula W, Y, 1 to 5 are listed below, but the heterocyclic compound of the present invention is not limited thereto.

The heterocyclic compound having the structure represented by the general formula W or Y contained in the non-photosensitive surface modifier of the present invention may be only one kind or two or more kinds.

From the perspective of solubility, the non-photosensitive surface modifier of the present invention preferably contains at least water or alcohol as a solvent. Examples of the alcohol include methanol, ethanol, 2-propanol, etc. Two or more types of water or alcohol may be used as a solvent. Specifically, the mass ratio of water to alcohol is preferably in the range of 100:0 to 50:50, and more preferably in the range of 100:0 to 75:25.

The content of the heterocyclic compound in the treatment solution of the non-photosensitive surface modifier is preferably in the range of 0.001 to 0.01 mass %, and is particularly preferably in the range of 0.001 to 0.005 mass % from the viewpoint of film formation.

In addition, the non-photosensitive surface modifier of the present invention may contain other components other than the above, but does not contain polymers, polymerizable monomers or oligomers, that is, does not contain resins, and the present invention is composed only of non-polymerizable materials. As the aforementioned other components, there can be listed: surfactants, preservatives, stabilizers, acids, bases, pH adjusters, etc.

[Laminar body] The laminate of the present invention is a laminate having a surface modification layer and a resin layer sequentially disposed on a metal layer, wherein the surface modification layer contains at least one heterocyclic compound having a structure represented by the aforementioned general formula 1, 2, 3 or 4.

The heterocyclic compounds having the structures represented by the general formulae 1 to 4 are the same as those described above, and thus their description is omitted.

In addition, among the heterocyclic compounds having the structures represented by the general formulae 1 to 4, the heterocyclic compound having the structure represented by the general formula 1 is preferred from the viewpoint of improving the adhesion between the metal layer and the resin layer through the interaction between the metal layer and the surface modified layer and between the surface modified layer and the resin layer. In particular, the heterocyclic compound having the structure represented by the general formula 5 is preferred from the viewpoint of improving the adhesion between the metal layer and the resin layer.

In the laminate of the present invention, the heterocyclic rings of the heterocyclic compound are oriented in a direction substantially perpendicular to the metal layer, and the alkylamine groups of the heterocyclic compound are oriented in a direction substantially perpendicular to the resin layer. This makes it possible to bring the alkylamine groups closer to the resin layer, further obtaining a stronger interaction and improving adhesion, which is preferable.

Regarding the orientation of the aforementioned heterocyclic compound, for example, the structure was optimized by DFT calculation using B3LYP (density functional method) using the quantization calculation software Gaussian16 (manufactured by Gaussian). For copper, SDD (Stuttgart/Dresden ECP) was used as the basis function, and 6-31G (d) was used for other elements. Then, in the Grid scan module of the software Material Science Suite manufactured by Schrodinger, the position where the copper ion is stabilized again in the space around the ligand is used as the initial configuration. Regarding the optimal structure calculated above, for example, the exemplary compound (1) is used as an example for explanation. As shown in FIG2 , it is preferred that the site where the compound (exemplary compound (1)) interacts with copper (Cu) is set as the axial direction, and when a center line A is drawn at the center of the compound in a manner perpendicular to the aforementioned axial direction, the site where the compound interacts with copper (Cu) and the alkylamine group are oriented in a manner that they are on opposite sides of the center line A.

Specifically, when the optimized structure calculated above is presented in Winmostar, the angles represented by the copper atom (Cu) (symbol 101 in FIG. 2)-nitrogen atom (N) in the structure of the heterocyclic compound (symbol 102 in FIG. 2)-nitrogen atom (N) at the terminal of the alkylamine group (symbol 103 in FIG. 2) are preferably selected to be at least 140° or more (refer to FIG. 2). For example, in the exemplary compound (1), the angle formed by the copper atom-nitrogen atom in the structure of the heterocyclic compound-nitrogen atom at the terminal of the alkylamine group is 170°, the exemplary compound (3) is 170°, and the exemplary compound (4) is 177°. Other exemplary compounds are shown in Table 3 below. Through this coordination, the nitrogen atom (N) and the alkylamine group that interact with copper in the structure of the aforementioned heterocyclic compound exist at the diagonal corners of the molecular skeleton. Therefore, the nitrogen atom (N) exists in a direction perpendicular to the metal layer 10, and the alkylamine group can be closer to the resin layer 20, further obtaining a strong interaction (see Figure 1).

The multilayer body of the present invention can be applied to, for example, a printed circuit board (printed wiring board) or an electronic device. The printed circuit board can be formed by forming a metal wiring pattern by photolithography as described later. In addition, as the electronic device, for example, there can be listed: a smart phone, a tablet terminal, a personal computer, a server, a router, a communication base station, a display device, a home appliance, etc.

The structure of the laminate of the present invention is described below. The laminate of the present invention is a laminate obtained by sequentially providing a surface modification layer and a resin layer on a metal layer. That is, the metal layer and the surface modification layer are adjacent to each other, and the surface modification layer and the resin layer are adjacent to each other.

<Metal layer> The metal layer is a layer with metal as the main component. The main component refers to a component containing 50% by mass or more.

As the metal used for the metal layer, for example, gold, silver, platinum, zinc, palladium, rhodium, zirconium, ruthenium, iridium, copper, nickel, cobalt, iron, tin, chromium, titanium, tungsten, indium, aluminum, lead, molybdenum, etc. or their alloys can be used. Among them, copper or a copper alloy is preferably used as the main component from the viewpoint of processability and conductivity.

The metal layer can be formed by metal foil, electroplating, or vacuum film forming.

The thickness of the metal layer is not particularly limited, and can be set to a thickness corresponding to the thickness of the metal wiring pattern to be formed, for example.

In forming the metal wiring pattern, a metal laminate having a metal layer formed on an insulating layer is used, so the laminate of the present invention preferably has an insulating layer below the metal layer. The insulating layer is not particularly limited, and a resin sheet or prepreg generally used as an insulating layer can be used.

As described above, the laminate having the insulating layer is shown in the figure, which corresponds to the laminate 6 in FIG. 5 showing the step of forming the anti-etching layer described later.

<Surface modification layer> The surface modification layer can be formed by applying the non-photosensitive surface modification agent of the present invention to the surface of the aforementioned metal layer and drying it.

The thickness of the surface modification layer is not particularly limited, but from the perspective of the effect of the present invention, it is preferably in the range of 0.1 to 20 nm.

＜Resin layer＞ The resin layer used in the present invention is not particularly limited, but can be exemplified by: thermoplastic resins such as acrylonitrile/styrene copolymer resin (AS resin), acrylonitrile/butadiene/styrene copolymer resin (ABS resin), fluororesin, polyamide, polyethylene, polyethylene terephthalate, polyvinylidene chloride, polyvinyl chloride, polycarbonate, polystyrene, polysulfone, polypropylene, cycloolefin resin, liquid crystal polymer, etc.; thermosetting resins such as epoxy resin, phenol resin, polyimide, polyurethane, dibutylene diimide/triazine resin, modified polyphenylene ether, cyanate ester, etc.; or ultraviolet curing resins such as ultraviolet curing epoxy resin, ultraviolet curing acrylic resin, etc. These resins can be modified with functional groups or reinforced with glass fibers, aromatic polyamide fibers, and other fibers.

When the laminate of the present invention is a printed circuit board laminate, the resin layer can use commercially available resin films or prepregs (sheet fibers impregnated with liquid resin), preferably resins containing fluororesins, cycloolefin resins, liquid crystal polymers, epoxy resins, phenolic resins, polyimide, dibutylene diimide/triazine resins, modified polyphenylene ethers, and cyanate esters. In addition, when the laminate of the present invention forms wiring of a printed circuit board (in the case of a metal wiring pattern), the resin layer can use a commercially available liquid anti-etching agent or dry film anti-etching agent, preferably a UV-curable epoxy resin, UV-curable acrylic resin, or polyimide containing an alkali-soluble resin.

The method for forming a metal wiring pattern of the present invention is a method for forming a metal wiring pattern by photolithography, wherein the method preferably includes a step of using the non-photosensitive surface modifier of the present invention to form a surface modification layer between a metal layer and an anti-etching agent.

<Method for forming a metal wiring pattern> Specifically, a metal wiring pattern is formed by the following steps (A) to (F). Step (A): A step of acid cleaning a metal laminate having a metal layer formed on an insulating layer. Step (B): A step of forming a surface modification layer on the metal layer of the metal laminate using the non-photosensitive surface modifier of the present invention. Step (C): A step of forming an anti-etching layer containing a photosensitive resin on the surface modification layer. Step (D): A step of patterning the anti-etching layer by exposure and development. Step (E): A step of etching the surface modification layer and the metal layer through the anti-etching layer. Step (F): a step of peeling off the aforementioned anti-corrosion layer from the aforementioned metal laminate

Each step is explained with reference to Figures 3 to 8.

In step (A), the metal laminate 5 (see FIG. 3 ) having the metal layer 2 formed on the insulating layer 1 is acid-cleaned. In this way, stains, antioxidants, oxide films, etc. attached to the metal surface that hinder the interaction between the non-photosensitive surface modifier and the metal layer can be removed. The acid cleaning liquid is not particularly limited, and a previously known acid cleaning liquid can be used. In addition, water washing can also be performed after the acid cleaning.

The insulating layer 1 is an insulating layer that serves as a base material of the metal wiring pattern. The insulating layer 1 is composed of an insulating material such as resin, or may be a prepreg in which a base material such as paper or glass is impregnated with resin.

The metal layer 2 is the same as the metal layer of the above-mentioned laminate.

In step (B), the non-photosensitive surface modifier of the present invention is used to form a surface modification layer 3 on the metal layer 2 of the metal laminate 5 (see FIG. 4 ). Specifically, the non-photosensitive surface modifier is applied to the metal layer 2 to form the surface modification layer 3. The thickness of the surface modification layer 3 is not particularly limited, but is preferably in the range of 0.1 to 20 nm from the viewpoint of the effect of the present invention.

Between step (B) and the subsequent step (C), it is preferred to have a step of washing the metal laminate 5 having the surface modification layer 3 formed thereon. This can remove the excess non-photosensitive surface modification agent that does not sufficiently interact with the metal layer.

In step (C), an anti-etching layer 4 containing a photosensitive resin is formed on the surface modification layer 3 (see FIG. 5 ). The laminate 6 in this state has the metal layer 2, the surface modification layer 3 and the anti-etching layer 4, and thus corresponds to the laminate of the present invention.

The anti-etching layer 4 is not particularly limited as long as it contains a photosensitive resin that can be patterned by photolithography similar to the anti-etching layer of the above-mentioned laminate, and can be formed by laminating a dry film anti-etching agent or applying a liquid anti-etching agent material.

In step (D), the anti-corrosion layer 4 is patterned by exposure and development (see FIG. 6 ). Specifically, the anti-corrosion layer 4 is exposed using a mask that can expose the anti-corrosion layer 4 in an arbitrary pattern, and then the unnecessary portion of the anti-corrosion layer 4 is dissolved and removed using a developer, thereby patterning. After development, it is preferably washed with water.

The exposure conditions and the development conditions are not particularly limited, and conventionally known conditions can be applied.

In step (E), the surface modification layer 3 and the metal layer 2 are etched through the anti-etching layer 4 (see FIG. 7 ). Specifically, the surface modification layer 3 and the metal layer 2 are patterned by dissolving the removed portions of the anti-etching layer 4 through wet etching using an etching solution.

The etching conditions are not particularly limited, and conventionally known conditions can be applied.

In step (F), the anti-corrosion layer 4 is peeled off from the metal laminate 5 (see FIG8 ). The surface modification layer 3 is easily peeled off from the anti-corrosion layer 4 due to the effect of the present invention, so the surface modification layer 3 is easily left on the metal layer 2 of the metal laminate 5, but the surface modification layer 3 may remain on the metal layer 2 or be peeled off together with the anti-corrosion layer 4.

The method for stripping the anti-corrosion layer 4 is not particularly limited, but it is preferably stripped using a stripping liquid. The stripping liquid is not particularly limited, and a conventionally known stripping liquid can be used.

Through the above steps, the metal wiring pattern 7 can be formed.

The above-mentioned method for forming a metal wiring pattern can form a high-density and high-precision metal wiring pattern. By attaching necessary electronic components to the metal wiring pattern, the high-density and high-precision printed circuit board (printed wiring board) of the present invention can be manufactured.

<Method for forming a printed circuit board laminate> The method for forming a laminate (printed circuit board laminate) of the present invention is a method for forming a resin layer on a metal layer, which includes a step of using the non-photosensitive surface modifier of the present invention to form a surface modification layer between the metal layer and the resin layer. The metal layer may be full-screen or patterned, and the lamination method may be a known method such as heat pressing. As the resin layer, a commercially available resin film or prepreg (sheet fiber impregnated with a liquid resin) can be used. Preferably, a resin including a fluororesin, a cycloolefin resin, a liquid crystal polymer, an epoxy resin, a phenolic resin, a polyimide, a dibutylene diimide/triazine resin, a modified polyphenylene ether, or a cyanate ester is used. The bonding surface of the resin layer can be subjected to a surface treatment such as a corona treatment or a plasma treatment before lamination. [Example]

The present invention is specifically described below by way of examples, but the present invention is not limited thereto. It should be noted that, in the following examples, unless otherwise specified, all operations were performed at room temperature (25° C.). In addition, unless otherwise specified, “%” and “parts” refer to “mass %” and “mass parts”, respectively.

The compounds used below are the aforementioned illustrative compounds (1), (3) to (7), (11), (12), (19), (22), (24), (26), (30) and the following comparative compounds 1 to 5.

[Example 1] <Preparation of non-photosensitive surface modifier 1> The aforementioned exemplary compound (1) was added to a solvent consisting of 20% by mass of ethanol and 80% by mass of ion-exchanged water in an amount of 0.002% by mass (20% by mass ppm) to prepare non-photosensitive surface modifier 1.

<Preparation of non-photosensitive surface modifiers 2 to 15 and C1 to C8> Non-photosensitive surface modifiers 2 to 13 and C1 to C8 were prepared in the same manner as the surface modifier 1 except that the types and concentrations of the compounds were changed as shown in Table 1 below. In addition, non-photosensitive surface modifiers 14 and 15 were prepared by changing the ratio of ethanol and ion-exchanged water as shown in Table 1 below.

<Formation of metal wiring pattern (laminate) 1> The following steps (A) to (F) are performed to form metal wiring pattern 1. [Step (A)] A copper foil laminate (R-1766 manufactured by Panasonic Corporation) having a metal layer formed on an insulating layer is acid-cleaned using an acid cleaning solution (CP-30 manufactured by Sanwa-Technic Inc.) and a spray-type cleaning device, and then washed with water.

[Step (B)] Use a spray coating device to apply the non-photosensitive surface modifier 1 prepared above to the metal layer of the copper foil laminate that has been acid-cleaned and water-washed, and then wash it with water. After washing, use a PVA roller to remove water, and dry it with an air knife at 80°C to form a surface modification layer with a thickness of 5nm.

[Step (C)] On the surface modification layer, a dry film anti-etching agent (AK-4034 manufactured by Asahi Kasei Corporation) was deposited by a hot roll laminating press at a roll temperature of 105°C, an air pressure of 0.35 MPa, and a deposition speed of 1.5 m/min to form an anti-etching layer. Note that the dry film anti-etching agent (AK-4034 manufactured by Asahi Kasei Corporation) used has a support body composed of a polyethylene terephthalate film on one side and a protective layer composed of a polyethylene film on the other side. The deposition is performed by peeling off the protective layer and bonding the surface of the protective layer to the metal layer through the surface modification layer.

[Step (D)] The resist layer is exposed using a chromium glass mask with a parallel light exposure machine (HMW-801 manufactured by ORC MANUFACTURING CO., LTD.). The exposure condition is 60 mj/cm ² , which is the recommended condition for dry film resist. After exposure, the support is peeled off from the resist layer. Thereafter, a developer composed of a 1 mass % sodium carbonate (Na ₂ CO ₃ ) aqueous solution and an alkaline developer are used to dissolve and remove the unexposed portion of the resist layer at 30°C, followed by water washing and development. Through the above operation, the resist layer is patterned.

[Step (E)] The surface modification layer and the metal layer were etched by immersion using an etching solution composed of an aqueous solution of 2 mass % hydrochloric acid (HCl) and 2 mass % ferric chloride (FeCl ₃ ) at a temperature of 30° C. and an immersion time (1 minute).

[Step (F)] The anti-corrosion layer was peeled off from the copper foil laminate at a temperature of 50°C using a stripping solution consisting of a 3 mass % sodium hydroxide (NaOH) aqueous solution.

<Formation of metal wiring patterns 2 to 15 and C1 to C8> In the formation of the aforementioned metal wiring pattern 1, except for changing each non-photosensitive surface modifier 2 to 15 and C1 to C8 as shown in Table 1 below, the metal wiring patterns 2 to 15 and C1 to C8 are formed in the same manner as the formation of the non-photosensitive surface modifier 1.

<Initial anti-corrosion adhesion> The metal wiring pattern formed above was observed under a microscope, and the initial anti-corrosion adhesion (anti-corrosion adhesion before storage (fine line formation)) was evaluated according to the following criteria. The evaluation results are shown in Table 1 below. AAA: The metal wiring residue rate is 99% or more. AA: The metal wiring residue rate is 97% or more and less than 99%. A: The metal wiring residue rate is 95% or more and less than 97%. B: The metal wiring residue rate is less than 95%.

[Example 2] <Anti-corrosion agent adhesion after storage> Each of the non-photosensitive surface modifiers prepared above was sealed and stored in a dark place at room temperature for 1 month, and then a metal wiring pattern was formed in the same manner as above. The formed metal wiring pattern was observed under a microscope, and the anti-corrosion agent adhesion after storage was evaluated according to the following criteria. The evaluation results are shown in Table 2 below. (Criteria) AAA: The metal wiring residue rate is 99% or more. AA: The metal wiring residue rate is 97% or more and less than 99%. A: The metal wiring residue rate is 95% or more and less than 97%. B: The metal wiring residue rate is less than 95%.

<Storage stability> The evaluation of the initial anti-corrosion agent adhesion in Example 1 was compared with the evaluation of the anti-corrosion agent adhesion after storage. If the evaluation results were the same, the evaluation was "A", and if the evaluation results of the anti-corrosion agent adhesion after storage were worse, the storage stability evaluation was "B". The results are shown in Table 2 below.

[Example 3] The orientation of each compound listed in Table 3 below was evaluated. Specifically, the structure was optimized by DFT calculation using B3LYP (density functional method) using quantization calculation software Gaussian16 (manufactured by Gaussian). For copper, SDD (Stuttgart/Dresden ECP) was used as the basis function, and 6-31G (d) was used for other elements. In the Grid scan module of the Material Science Suite software manufactured by Schrodinger, the position where the copper ion is stabilized again in the space around the ligand is taken as the initial configuration. When the optimized structure calculated above is presented in Winmostar, the angle represented by the nitrogen atom (N) in the structure of the copper atom (Cu)-heterocyclic compound-the terminal nitrogen atom (N) of the alkylamine group is selected, and the orientation is evaluated according to the following criteria. (Criteria) A: The angle of the copper atom-nitrogen atom-terminal nitrogen atom is greater than 140°. B: The angle of the copper atom-nitrogen atom-terminal nitrogen atom is greater than 0° and less than 140°.

As shown in the above results, it can be seen that in the heterocyclic compound contained in the non-photosensitive surface modifier of the present invention, the nitrogen atom in its skeleton structure is located at a position almost opposite to the alkylamine group, and the molecular skeleton is coordinated in the vertical direction. Then, compared with the case of using the surface modifier of the comparative example, the non-photosensitive surface modifier of the present invention containing such a heterocyclic compound with similar orientation has excellent anti-corrosion agent adhesion, and since the anti-corrosion agent adhesion is excellent after long-term storage, it is recognized that its storage stability is good. [Industrial Utilization]

The present invention is a non-photosensitive surface modifier which can further improve the adhesion between a metal layer and a resin layer and has excellent storage stability, and can be used in laminates, printed circuit boards and electronic devices.

1: Insulation layer 2: Metal layer 3: Surface modification layer 4: Anti-corrosion layer 5: Metal laminate 6: Laminated body 7: Metal wiring pattern 10: Metal layer 20: Resin layer 30: Surface modification layer 101: Copper atoms 102,103: Nitrogen atoms A: Center line

[Figure 1] is a schematic diagram showing the coordination state of nitrogen atoms and alkylamine groups in the structure of the heterocyclic compound of the present invention [Figure 2] is a diagram for explaining the orientation of the heterocyclic compound of the present invention [Figure 3] is a diagram showing the formation step of the metal wiring pattern (metal lamination plate) [Figure 4] is a diagram showing the formation step of the metal wiring pattern (formation of surface modification layer) [Figure 5] is a diagram showing the formation step of the metal wiring pattern (formation of anti-corrosion layer) [Figure 6] is a diagram showing the formation step of the metal wiring pattern (patterning of anti-corrosion layer) [Figure 7] is a diagram showing the formation step of the metal wiring pattern (etching of surface modification layer and metal layer) [Figure 8] is a diagram showing the steps of forming a metal wiring pattern (stripping of the anti-etching layer).

10: Metal layer 20: Resin layer 30: Surface modification layer

Claims (11)

A non-photosensitive surface modifier is a non-photosensitive surface modifier that forms a surface modification layer between a metal layer and a resin layer, wherein the non-photosensitive surface modifier contains at least a heterocyclic compound having a structure of the following general formula W or general formula Y, wherein the concentration of the heterocyclic compound is in the range of 0.001 to 0.01 mass %, In the formula, Rn ₁ and Rn ₂ are alkyl groups; L is a linking group; W ₁ to W ₇ are carbon atoms or nitrogen atoms, at least 2 of which are nitrogen atoms, one of which is NH, and W ₁ to W ₇ form a condensed ring; Y ₁ to Y ₅ are carbon atoms or nitrogen atoms, at least 2 of which are nitrogen atoms, one of which is NH, and Y ₁ to Y ₅ form a heterocyclic ring; m is an integer greater than 1. The non-photosensitive surface modifier as claimed in claim 1, wherein the heterocyclic compound has at least a structure represented by the following general formula 1, 2, 3 or 4, In the formula, _Rn1 and _Rn2 are alkyl groups; L is a linking group; _R1 is a hydrogen atom, an alkyl group, an aryl group or a heteroaryl group, and may further have a substituent; _R2 is an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a carboxyl group, an ester group, an amide group, a heteroaryl group or a halogenated group; each n is an integer of 0 to 4; m is an integer greater than 1; when there are multiple substituents _R2 , each substituent _R2 may be the same as or different from each other; in addition, when there are multiple n, each n may be the same as or different from each other, and further, when there are multiple m, each m may be the same as or different from each other. The non-photosensitive surface modifier as described in claim 2, wherein the heterocyclic compound has the structure represented by the general formula 1. The non-photosensitive surface modifier as described in claim 1, wherein the heterocyclic compound has a structure represented by the following general formula 5: In the formula, _Rn1 and _Rn2 are alkyl groups; L is a linking group; _R2 is an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a carboxyl group, an ester group, an amide group, a heteroaryl group or a halogenated group; each n is an integer of 0 to 4; m is an integer greater than 1; when there are multiple substituents _R2 , each substituent _R2 may be the same or different. The non-photosensitive surface modifier as described in any one of claims 1 to 4 contains at least water or alcohol. A laminate comprising a surface modification layer and a resin layer sequentially disposed on a metal layer, wherein the surface modification layer contains at least a heterocyclic compound having a structure represented by the following general formula 1, 2, 3 or 4, In the formula, _Rn1 and _Rn2 are alkyl groups; L is a linking group; _R1 is a hydrogen atom, an alkyl group, an aryl group or a heteroaryl group, and may further have a substituent; _R2 is an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a carboxyl group, an ester group, an amide group, a heteroaryl group or a halogenated group; each n is an integer of 0 to 4; m is an integer greater than 1; when there are multiple substituents _R2 , each substituent _R2 may be the same as or different from each other; in addition, when there are multiple n, each n may be the same as or different from each other, and further, when there are multiple m, each m may be the same as or different from each other. The laminate as described in claim 6, wherein the heterocyclic compound has the structure represented by the general formula 1. The laminate as claimed in claim 6, wherein the heterocyclic compound has a structure represented by the following general formula 5: In the formula, _Rn1 and _Rn2 are alkyl groups; L is a linking group; _R2 is an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a carboxyl group, an ester group, an amide group, a heteroaryl group or a halogenated group; each n is an integer of 0 to 4; m is an integer greater than 1; when there are multiple substituents _R2 , each substituent _R2 may be the same or different. The laminate as described in claim 6, wherein the resin layer is a photosensitive resin composition containing an alkali-soluble resin. A printed substrate using the laminate as described in any one of claims 6 to 9. An electronic device using the multilayer body as described in any one of claims 6 to 9.