CN108141961B

CN108141961B - Method for manufacturing resin laminate with wiring pattern

Info

Publication number: CN108141961B
Application number: CN201680058524.3A
Authority: CN
Inventors: 松岛敏文
Original assignee: Mitsui Mining and Smelting Co Ltd
Current assignee: Mitsui Mining and Smelting Co Ltd
Priority date: 2015-11-27
Filing date: 2016-11-01
Publication date: 2020-08-14
Anticipated expiration: 2036-11-01
Also published as: KR102547264B1; TW201728463A; WO2017090386A1; JP6807864B2; KR20180088370A; CN108141961A; TWI716484B; JPWO2017090386A1

Abstract

The method for manufacturing a resin laminate with a wiring pattern according to the present invention includes the steps of: a step of providing an etching resist layer (3) or a wiring pattern layer (14) on the surface of a copper layer (2, 12) in a laminate comprising resin layers (1, 11) of a polyvinyl acetal resin and the copper layer so as to form 1 st openings (8, 18) where the copper layer is exposed; and a step of removing the copper layer exposed in the 1 st opening by using an etching solution having an etching ability for copper and containing substantially no chlorine, thereby exposing the surface of the resin layer on the copper layer side.

Description

Method for manufacturing resin laminate with wiring pattern

Technical Field

The present invention relates to a method for producing a wiring-patterned resin laminate from a laminate of a resin layer containing a polyvinyl acetal resin and a copper layer.

Background

Conventionally, in a laminate having a transparent resin film and a metal layer such as copper laminated on the film, it has been proposed to use an element having a metal electrode pattern obtained by photolithography and etching of the metal layer as a transparent heat-radiating panel or the like. As one of the transparent resins, a polyvinyl acetal resin such as polyvinyl butyral is known (for example, patent document 1).

On the other hand, as an etching solution for etching a copper layer laminated on a resin base material to form a copper wiring on the resin base material, a chlorine-containing etchant such as copper chloride is often used (for example, patent document 2).

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2007-102002

Patent document 2: japanese patent laid-open publication No. 2013-80735

Disclosure of Invention

However, since transparency is increasingly required for transparent resins with circuits used for transparent heat-radiating panels and the like, it has been required that transparency of the transparent resin is not lowered by discoloration and the like in etching of a copper layer in forming the circuits. In this regard, etching of a laminate of a resin layer containing a polyvinyl acetal resin and a copper layer is no exception.

The present invention addresses the problem of providing a method for manufacturing a resin laminate with a wiring pattern, which can eliminate the disadvantages of the conventional techniques described above.

The invention provides a method for manufacturing a resin laminate with a wiring pattern, which comprises the following steps: a step of providing a resist layer or a wiring pattern layer on the surface of a copper layer in a laminate of a resin layer containing a polyvinyl acetal resin and the copper layer so as to form a 1 st opening through which the copper layer is exposed; and the combination of (a) and (b),

and removing the copper layer exposed in the 1 st opening by using an etching solution having an etching ability for copper and containing substantially no chlorine, thereby exposing the surface of the resin layer on the copper layer side.

Drawings

Fig. 1 (a) to 1 (e) are schematic diagrams showing a circuit formation step in the subtraction method.

Fig. 2 (a) to 2 (f) are schematic diagrams showing a circuit forming step in the additive method.

Detailed Description

The present invention will be described below based on preferred embodiments. The method for producing a resin laminate with a wiring pattern according to the present invention (hereinafter, also referred to as "the method of the present invention") includes the steps of: a step of providing a resist layer or a wiring pattern layer on a surface of a copper layer in a laminate of a resin layer containing a polyvinyl acetal resin and the copper layer so as to form a 1 st opening through which the copper layer is exposed (hereinafter, also referred to as "1 st step"); and the combination of (a) and (b),

and a step (hereinafter, also referred to as "step 2") of removing the copper layer exposed in the first opening by using an etching solution having an etching ability for copper and containing substantially no chlorine, thereby exposing the surface of the resin layer on the copper layer side. In the present invention, the "copper layer" refers to a layer made of pure copper or a copper alloy, and typically, the copper content is preferably 95 mass% or more in terms of conductivity, etching processability, and the like of the copper layer. As a wiring pattern of the resin laminate with a wiring pattern, a wiring circuit made of copper can be given.

As described above, the present inventors have found that, in a method for producing a resin laminate with a wiring pattern when forming a circuit on a transparent resin substrate, it is required to prevent discoloration of the transparent resin: when a copper layer in a laminate having a resin layer containing a polyvinyl acetal resin and a copper layer is etched with copper chloride, the resin layer is easily yellowed. Yellowing reduces the product value of a transparent heat-radiating panel in which a circuit is formed on a transparent resin substrate. The inventor finds that: this yellowing can be prevented by etching the copper layer with an etchant that does not substantially contain chlorine.

Examples of a circuit forming method to which the method of the present invention is applied include a subtractive method, a semi-additive method, and a modified semi-additive method. In the subtractive method, a resist layer is provided in the first step 1, and in the case of the semi-additive method and the modification semi-additive method, a wiring pattern layer is provided in the first step 1. In the following description, the semi-addition method and the modification semi-addition method may be collectively referred to simply as an addition method.

First, a case where the method of the present invention is applied to circuit formation by a subtraction method will be described with reference to (a) to (e) of fig. 1. Fig. 1 and 2 are schematic, and therefore do not show an actual dimensional relationship.

In the subtractive method, a laminate 10 of a resin layer 1 containing a polyvinyl acetal resin and a copper layer 2 shown in fig. 1 was used. The laminate 10 may be a resin-layer-equipped copper foil obtained by laminating a resin layer on one surface of a copper foil. The thickness of the copper layer 2 is, for example, preferably 1 μm or more and 30 μm or less, and more preferably 2 μm or more and 18 μm or less, from the viewpoint of handling of the laminate 10, ease of etching, and maintenance of conductivity for using the electrode pattern as a heat sink. The copper layer 2 is not particularly limited in terms of the production method, and may be formed by any method such as an electrolytic method, a rolling method, or a gas phase method. When the thickness of the copper layer is as thin as 10 μm or less, a copper foil with a carrier may be used for the purpose of improving workability. Here, the carrier-attached copper foil has a structure in which a carrier, a release layer, and an extra thin copper foil are laminated in this order. Examples of the carrier include metals such as copper, iron, stainless steel, and aluminum, alloys containing these metals as main components, heat-resistant resins such as polyesters and engineering plastics, and typically copper foil. The thickness of the carrier 15 is preferably 12 μm or more and 100 μm or less, more preferably 15 μm or more and 80 μm or less, from the viewpoint of transportability and crack resistance at the time of peeling. The release layer is used for facilitating the release of the extra thin copper foil from the carrier, and may be any of known organic release layers and inorganic release layers. Examples of the organic component used in the organic release layer include nitrogen-containing organic compounds, sulfur-containing organic compounds, carboxylic acids, and the like. Examples of the nitrogen-containing organic compound include a triazole compound and an imidazole compound, and among them, a triazole compound is preferable in terms of easy stabilization of releasability. Examples of the triazole compound include 1,2, 3-benzotriazole, carboxybenzotriazole, N' -bis (benzotriazolylmethyl) urea, 1H-1,2, 4-triazole and 3-amino-1H-1, 2, 4-triazole. Examples of the sulfur-containing organic compound include mercaptobenzothiazole, trithiocyanuric acid, and 2-benzimidazolethiol. Examples of the carboxylic acid include monocarboxylic acid and dicarboxylic acid. On the other hand, examples of the inorganic component used in the inorganic peeling layer include metals or alloys composed of at least one of Ni, Mo, Co, Cr, Fe, Ti, W, P, Zn, and the like, and/or oxides thereof. The thickness of the release layer is typically 1nm or more and 1 μm or less, and preferably 5nm or more and 500nm or less. The peel strength between the release layer and the carrier is preferably 2gf/cm or more and 50gf/cm or less, more preferably 5gf/cm or more and 30gf/cm or less, and further preferably 10gf/cm or more and 20gf/cm or less.

The resin layer used as the transparent resin substrate, which can be used in the present invention, is preferably made of a polyvinyl acetal resin. The polyvinyl acetal resin is obtained by acetalizing polyvinyl alcohol with an aldehyde, and the aldehyde used for acetalization generally includes an aldehyde having 1 to 10 carbon atoms. Specific examples thereof include n-butyraldehyde, isobutyraldehyde, n-valeraldehyde, 2-ethylbutyraldehyde, n-hexanal, n-octanal, n-nonanal, n-decanal, formaldehyde, acetaldehyde, and benzaldehyde. For example, as the polyvinyl acetal resin, polyvinyl butyral, which is a resin obtained by acetalizing polyvinyl alcohol with butylaldehyde, and polyvinyl formal, which is a resin obtained by acetalizing polyvinyl alcohol with formaldehyde, can be used. Among them, the polyvinyl butyral resin is preferably used from the viewpoints of flexibility of the transparent substrate, penetration impact resistance as an interlayer of glass or the like, lamination processability as an interlayer of glass or the like, color clarity, transparency, and the like.

When the resin layer 1 is used as a transparent base material, the content of the polyvinyl acetal resin in the resin layer 1 is typically 50 mass% or more from the viewpoints of maintaining the transparency of the transparent base material, the flexibility of the resin layer, maintaining the adhesion to the copper layer, and the like. The resin layer 1 may suitably contain, in addition to the polyvinyl acetal resin, for example, a plasticizer composed of an ester of a hydroxyl group-containing compound and a carboxylic acid-containing compound, an antioxidant, an ultraviolet absorber, a silane coupling agent, an adhesion-imparting agent such as a silicone compound, and the like.

The resin layer 1 can be formed by any conventionally known forming method such as an extrusion forming method, a casting method, a coating method, or a combination thereof. The resin layer 1 may be a commercially available polyvinyl acetal resin film.

The thickness of the resin layer 1 varies depending on whether or not the laminate with a circuit obtained by the method of the present invention is used for any application such as a display element, a touch panel, and a heating wire for window glass, but is generally preferably 30 μm to 3000 μm, more preferably 100 μm to 1500 μm, in view of the handleability of the laminate 10. The surface of the resin layer 1 may be subjected to embossing treatment in order to remove air bubbles generated when the interlayer such as glass is attached.

In the case of producing the laminate 10 by laminating the resin layer 1 and the copper layer 2 as in the steps (a) and (b) of fig. 1, a method of thermally pressing the laminate 10 may be used. As the heat-pressure bonding machine, a vacuum laminator, a vacuum press, or the like can be used. The heating temperature is preferably 40 ℃ to 120 ℃, more preferably 50 ℃ to 90 ℃, the pressurizing force is preferably 0.2MPa to 10MPa, more preferably 0.5MPa to 5MPa, and the pressurizing time is preferably 30 seconds to 120 seconds. In order to exert the effect of maintaining the transparency of the resin layer 1 at a higher level when forming the laminate with a circuit, it is preferable that the resin layer 1 and the copper layer 2 in the laminate 10 are directly bonded without interposing an adhesive layer therebetween. When the copper layer in the copper foil with a carrier is laminated with the resin layer 1 in the above-described manner, the carrier is mechanically peeled after lamination.

As shown in fig. 1 (c), in the subtractive method, the resist layer 3 is provided on the surface of the copper layer 2 opposite to the resin layer 1 so as to form the 1 st opening 8, through which the copper layer 2 is exposed, in the laminate 10. Examples of the resist layer 3 include: a coating type resist film used in a process based on screen printing, direct imaging, coating in the same shape as a wiring pattern; a photoresist film used in a process of forming the same image as the wiring pattern through steps of coating, laminating, exposure, development, and the like. Among them, the resist layer 3 is preferably formed of a photoresist film in terms of pattern processing accuracy, pattern formation processing speed, and the like. In this case, a layer of a photoresist film is provided on the entire upper surface of the copper layer 2 in the laminate 10, and then the portion of the layer to be a wiring pattern is exposed to light, and the portion other than the portion to be a wiring pattern is removed by development, whereby the resist layer 3 having the opening 8 of the 1 st opening 8 is obtained. As the photoresist film, either a negative type in which an exposed portion is cured or a positive type in which an exposed portion is dissolved may be used. Specifically, an acrylic resin such as an ester of (meth) acrylic acid is preferably used. The thickness of the resist layer 3 is preferably 1 μm or more and 30 μm or less, more preferably 3 μm or more and 25 μm or less, from the viewpoint of improving adhesion to the copper layer during etching.

In the 2 nd step, the copper layer 2 exposed in the 1 st opening 8 of the resist layer 3 is removed to expose the surface 1a of the resin layer 1 on the copper layer 2 side, as shown in fig. 1 (d), using an etching solution having etching ability for copper and containing substantially no chlorine.

The etching solution substantially containing no chlorine means that the content of chlorine in the etching solution is 100mg/L or less, and if it is in this range, it is preferable from the viewpoint of not affecting the prevention of yellowing of the resin layer in the present invention. More preferably, the chlorine content in the etching solution is 50mg/L or less, more preferably 10mg/L or less, and still more preferably 2mg/L or less. The concentration of chlorine in the etching solution can be measured by a conventionally known method such as an electrode method or a DPD method (diethyl-p-phenylenediamine method).

Examples of the etchant in the etching solution having an etching ability with respect to copper and containing substantially no chlorine include metal persulfate and ammonium persulfate, a mixed solution of sulfuric acid and hydrogen peroxide, and a mixed solution of sulfuric acid and iron sulfate. In particular, the use of persulfate salts is preferable because the influence of the etching treatment on the shape of the resist layer 3 and the adhesion between the resist layer 3 and the copper layer 2 is suppressed, and the wiring pattern obtained after etching becomes good. The present inventors speculate that the reason may be that the dissolution of the resist layer 3 is not easily caused when persulfate is used. As the persulfate, an alkali metal persulfate is preferable in terms of enhancing both the effect of preventing yellowing of the resin layer 1 and the effect of forming a circuit pattern well by etching and the effect of preventing adsorption of a metal component to the resin layer 1 during etching. Among the alkali metal salts of persulfuric acid, sodium persulfate or potassium persulfate (also referred to as sodium peroxodisulfate or potassium peroxodisulfate in some cases) is preferable from the viewpoint of availability and the like. These etchants can be used in 1 kind or 2 or more kinds in combination.

As a solvent for dissolving the etchant in the etching solution, water can be used, and an immersion method, a shower method, or the like can be suitably employed. The persulfate is more preferably contained in the etching solution at a concentration of 50g/L to 300g/L inclusive, and particularly preferably at a concentration of 80g/L to 200g/L inclusive, from the viewpoints of stability of the etching rate of the copper layer, prevention of uneven reaction due to variation in stirring rate and shower pressure, and the like. The concentration of persulfate in the etching solution can be measured by a back titration method.

The etchant may contain other components than the etchant as described above within a range not to impair the effects of the present invention. Examples of such components include sulfuric acid, surfactants, alcohols, and defoaming agents.

From the viewpoint of ensuring the etching rate and maintaining the stability of the liquid components, the temperature of the etching solution during etching is preferably 22 ℃ or higher and 60 ℃ or lower, and more preferably 25 ℃ or higher and 50 ℃ or lower.

The etching time can be adjusted as appropriate depending on the relationship among the thickness of the copper layer, the opening width of the resist film, the processing size, the etching rate of the etching solution, and the like.

As the etching method, a known method such as a spray method or a dipping method can be used. The method of the present invention exposes all or a part of the resin layer 1 located in the 1 st opening 8 of the resist layer 3.

Through the above steps, the resin laminate 9 with a wiring pattern can be obtained. After etching, the resultant etched product is washed with a cleaning liquid such as water. The cleaning liquid preferably contains substantially no chlorine. The term "substantially free of chlorine" means that the chlorine content in the cleaning liquid is 100mg/L or less. The chlorine content is preferably 50mg/L or less, more preferably 10mg/L or less.

Next, when the resist layer 3 is not removed in the etching step, the resist layer 3 may be removed as shown in fig. 1 (e) as an arbitrary step. The resist layer 3 can be removed by appropriately selecting a known agent for removing the photoresist layer, for example, spraying or dipping a caustic soda aqueous solution (2 to 5 mass% or the like) or the like to remove the photoresist layer.

The method for producing a resin laminate with a wiring pattern according to the present invention can be applied not only to a subtractive method but also to an additive method. An example of the application to the additive method will be described with reference to fig. 2.

In the first step 1 of the additive method, as shown in fig. 2 (a) and (b), a laminate 110 in which a seed layer is a copper layer 12 is used as a laminate of a resin layer and a copper layer. The seed layer is a layer to be an electrode when a metal layer (wiring pattern layer 14 described later) is laminated on the surface thereof by plating. As the resin layer 11, the same resin layer as the resin layer 1 described above in the case of the subtractive method can be used. Examples of the method for forming the seed layer include a chemical plating method, a vapor deposition method, and a copper foil lamination method using a copper foil with a carrier. However, when the resin layer is formed by the electroless plating method, chlorine in the plating solution may discolor the resin layer 110. Further, although the method by the vapor phase film formation method may include a sputtering method or a vacuum deposition method, in the case where the resin layer 1 is a polyvinyl acetal resin, contamination may be present in the seed crystal layer due to sublimation of the resin component. From these points of view, the copper foil lamination method using a copper foil with a carrier is most preferable in terms of prevention of discoloration by chlorine and prevention of contamination in the seed layer. The thickness of the seed layer is preferably 0.2 μm or more and 5.0 μm or less, more preferably 0.3 μm or more and 3.0 μm or less, from the viewpoint of easiness of flash etching (described later) and the like.

The carrier-attached copper foil used in the copper foil lamination method, the copper foil lamination conditions, and the like are the same as those described in the above subtraction method.

Next, as shown in fig. 2 (c), a plating resist layer 13 is provided on the surface of the copper layer 12 opposite to the resin layer 11 so as to form a 2 nd opening 17 where the copper layer 12 is exposed, on the copper layer 12 in the laminate 110. Such plating resist layer 13 is preferably formed of a photoresist film. In this case, a layer formed of a photoresist is provided on the entire upper surface of the copper layer 12 in the laminate 110, and then the wiring pattern is exposed to light, and the portion of the layer formed of the photoresist to be the wiring pattern is removed by development. Through this step, the plating resist layer 13 having the 2 nd opening 17 formed therein can be obtained. The thickness of the plating resist 13 is preferably thicker than the height of the wiring pattern layer 14 to be formed.

Next, as shown in fig. 2 (d), the wiring pattern layer 14 as a metal layer is formed in the 2 nd opening 17 by electrolytic plating. Copper is generally used as a metal constituting the wiring pattern layer 14. The concentration of chlorine in the metal plating solution in the electrolytic plating method is preferably 100mg/L or less, more preferably 50mg/L or less. However, when the electrolytic plating is performed in a state where the resin layer is covered with a protective layer such as a photoresist film on the side opposite to the electrolytic plating surface, the chlorine concentration in the metal plating solution does not necessarily need to be necessarily low. The thickness of the wiring pattern layer 14 is usually 2.0 μm or more and 30.0 μm or less. Thereafter, as shown in fig. 2 (e), the plating resist 13 is removed to obtain the wiring pattern layer 14 in which the 1 st opening 18 where the copper layer 12 is exposed is formed. For the removal of the plating resist layer 13, a sodium hydroxide aqueous solution, a mixed solution of an alkanolamine, an organic solvent, and water, or the like can be used.

Next, as a 2 nd step, flash etching is performed. Specifically, as shown in fig. 2 (f), the copper layer 12 exposed in the 1 st opening 18 is removed using an etching solution having an etching ability for copper and containing substantially no chlorine. This exposes the surface of the resin layer 11 on the copper layer 12 side.

As the etchant and the solvent in the etching solution, the same substances as in the case of the subtractive method can be used, respectively.

As described above, as the resin laminate with a wiring pattern by the additive method, the laminate 19 with a circuit in which a circuit is formed on the resin layer 11 can be obtained.

The other aspects of the method of the present invention in the addition method are the same as in the subtraction method.

The element obtained by the method for producing a resin laminate with a wiring pattern of the present invention as described above, in which a circuit of copper is formed on a resin layer containing a polyvinyl acetal resin, can effectively prevent discoloration of the resin layer, and therefore, the element can be suitably used as an element utilizing transparency of the resin layer, for example, a light emitting display element such as a traffic signal or a road sign, a touch panel in front of a display, a window glass for a tall building, a heating wire for a showcase, a heating wire for a window glass such as a front glass or a rear glass in a vehicle, and the like, while maintaining an originally clear color tone of the transparent resin layer. The electric heating wire of the window glass is used as a defroster, a defogger, and the like, and is disposed in an intermediate layer of the laminated glass.

Examples

The present invention will be described in further detail below with reference to examples. However, the scope of the present invention is not limited to these examples. Unless otherwise specified, "%" means "% by mass".

[ example 1]

(step 1)

The method of manufacturing a resin laminate with a wiring pattern in the step of the subtractive method shown in fig. 1 was evaluated.

As the resin layer 1, a commercially available polyvinyl butyral resin film (grade: Architectural Use, color: transparent, thickness: 760 μm) containing a plasticizer (dihexyl adipate: DHA) was used. A copper foil with a carrier (carrier: copper foil 18 μm in thickness, release layer: carboxybenzotriazole, extra thin copper foil 5 μm in thickness) was laminated on the polyvinyl butyral resin film by a vacuum laminator under conditions of 60 ℃ for 30 seconds and 1MPa so that the extra thin copper foil was in contact with the resin film, and then the carrier was mechanically peeled off to produce a laminate 10 having a resin layer 1 and a copper layer 2. A resist mask was formed thereon using a photoresist film (thickness 5 μm). Then, after forming a wiring pattern by ultraviolet irradiation using a photomask covering a portion to be patterned, a developing solution was developed using a sodium carbonate solution to remove the portion other than the portion of the wiring pattern, thereby forming a resist layer 3 having a 1 st opening 8 where the copper layer 2 is exposed (line width/line pitch (L/S) of the wiring forming portion: 10 μm/2000 μm).

(step 2)

An aqueous solution of sodium persulfate (concentration: 150g/L) was used as the etching solution. The concentration of chlorine in the etching solution was 1 mg/L. The laminate obtained in step 1 was subjected to etching treatment by the immersion method under conditions that etching (justthing) was performed using the etching solution (30 ℃) in an amount appropriate for just not allowing any residue to be observed in the opening 8. After etching, the circuit was washed with water (chlorine concentration 1mg/L), and then the resist film was removed with a 5% aqueous solution of sodium hydroxide, followed by washing with the above-mentioned water again and drying. The obtained laminate sample with circuit was prepared, and the resin yellowing factor and the resist adhesion during etching were evaluated by the following methods.

(resin yellowing degree)

A color difference meter: using Suga Test Instruments Co., Ltd., "Colour Cute i", pursuant to JISK7373, a standard illuminant D was used₆₅X is obtained from the following formula₁₀Y₁₀Z₁₀Yellowness YI in the color system. The blank and the increase (%) in the yellowness YI of the etched sample were determined using the sample without the copper foil as the blank. Based on the obtained increase rate, evaluation was performed according to the following evaluation criteria. The results are shown in Table 1.

A: the increase rate is less than 0.3 percent

B: the increasing rate is more than 0.3 percent and less than 1.0 percent

C: the increasing rate is more than 1.0 percent and less than 3.0 percent

D: the increase rate is more than 3.0 percent

YI＝100(1.3013X₁₀-1.1498Z₁₀)/Y₁₀

(resist film adhesion during etching)

Regarding the defect rate of the pattern after etching, with respect to the line width/line spacing (L/S): the wiring pattern of 10 μm/2000 μm was observed with a solid microscope (200 times). In each wiring, a defective pattern was determined, and the pattern defect rate (%) thereof was calculated (number of wirings determined to be defective/50 wirings observed) × 100). Based on the pattern defect rate, the adhesiveness of the resist film during etching was evaluated according to the following criteria. The results are shown in Table 1.

A: the pattern reject ratio is less than 5 percent

B: the pattern reject ratio is more than 5% and less than 10%

C: the pattern reject ratio is more than 10% and less than 20%

D: the defective rate of the pattern is more than 20%

[ example 2 ]

A sulfuric acid/hydrogen peroxide aqueous etchant (made by Meltex corporation, Enplate E-462, sulfuric acid concentration: 70g/L, hydrogen peroxide aqueous concentration: 10g/L) was used. The concentration of chlorine in the etching solution was 0.5 mg/L. A laminate with a circuit was produced and evaluated in the same manner as in example 1, except that this etching solution was used. The results are shown in table 1.

[ comparative example 1]

Copper chloride and hydrochloric acid were added to water and mixed to prepare an aqueous solution having a copper chloride concentration of about 135g/L and a hydrochloric acid concentration of 105g/L (chlorine concentration: 102 g/L). A laminate with a circuit was produced and evaluated in the same manner as in example 1, except that the etching treatment temperature was set to 45 ℃. The results are shown in table 1.

[ comparative example 2 ]

A laminate with a circuit was produced and evaluated in the same manner as in example 1, except that a stock solution of A-Process (trade name, manufactured by Meltex corporation) was used as it is as an etching solution and the treatment temperature was set to 45 ℃. The results are shown in table 1.

In the stock solution, the concentration of the ammine copper complex salt was 250g/L (copper concentration: 11g/L), the concentration of ammonium chloride was 150g/L (chlorine concentration: 99g/L), and the concentration of ammonia was 50 g/L.

[ example 3 ]

In this example, the method of manufacturing a resin laminate with a wiring pattern in the step of the additive method shown in fig. 2 was evaluated. As the resin layer 11, a polyvinyl butyral resin film used in example 1 was prepared, a carrier-attached copper foil similar to the copper foil used in example 1 except that the thickness of the ultra-thin copper layer was 2 μm was laminated on the surface thereof, and then the carrier was peeled off, thereby forming a copper layer 12 as a seed layer having a thickness of 2 μm on the resin layer 11. A resist mask was formed on the copper layer 12 using a plating resist (thickness: 25 μm). Next, after forming a wiring pattern by ultraviolet irradiation using a photomask, the wiring pattern is partially removed by development using a sodium carbonate solution as a developer, and a plating resist 13 having a 2 nd opening 17 in which the copper layer 12 is exposed is formed. Next, a wiring pattern layer 14, which is a pattern having a thickness of 20 μm and a line width/line pitch of 10 μm/200 μm, was formed in the opening of the plating resist by copper electroplating. Next, the plating resist layer 13 was removed by using an aqueous solution of sodium hydroxide to form the 1 st opening 18, and then etched by using an aqueous solution of sodium persulfate (concentration: 150g/L) (chlorine concentration: 1mg/L, temperature: 50 ℃ C.). The etching treatment is carried out by a dipping method until a proper amount of etching is performed. After etching, the laminate was washed with water (chlorine concentration 1mg/L) and dried. The obtained laminate with circuit was evaluated by obtaining the increase rate of the resin yellowness by the above-described method. The results are shown in table 1. Table 1 shows numerical values of the yellowness increase rate (%) and the pattern defect rate (%) in addition to the 4-stage evaluations a to D as the resin yellowness and the resist adhesion.

[ Table 1]

As shown in table 1, the use of the etchant of each example containing substantially no chlorine effectively suppressed yellowing of the resin layer containing the polyvinyl acetal resin, whereas the use of the etchant of each comparative example containing a chlorine etchant determined yellowing of the resin. In the subtractive method, the evaluation of adhesion (pattern goodness) during etching was judged to be high when persulfate was used as the etchant.

Industrial applicability

According to the present invention, a method for producing a resin laminate with a wiring pattern, which is excellent in yellowing resistance of a resin layer containing a polyvinyl acetal resin, can be provided.

Claims

1. A method for manufacturing a resin laminate with a wiring pattern, comprising the steps of:

a step of providing a resist layer or a wiring pattern layer on the surface of a copper layer in a laminate of a resin layer containing a polyvinyl acetal resin and the copper layer so as to form a 1 st opening through which the copper layer is exposed; and the combination of (a) and (b),

and removing the copper layer exposed in the 1 st opening by using an etching solution having an etching ability for copper and substantially not containing chlorine, thereby exposing the surface of the resin layer on the copper layer side to form a wiring pattern.

2. The method for manufacturing a resin laminate with a wiring pattern according to claim 1, wherein a chlorine content in the etching solution is 100mg/L or less.

3. The method for manufacturing a wiring-pattern-provided resin laminate according to claim 1, wherein a laminate having a seed layer as the copper layer is used as the laminate,

a plating resist is provided on the copper layer in the laminate so as to form a 2 nd opening where the copper layer is exposed, and then a wiring pattern layer is formed in the 2 nd opening by electrolytic plating, and then the plating resist is removed, whereby the wiring pattern layer is provided so as to form the 1 st opening where the copper layer is exposed.

4. The method for producing a resin laminate with a wiring pattern according to any one of claims 1 to 3, wherein the etchant of the etching solution contains a persulfate.

5. The method for producing a resin laminate with a wiring pattern according to any one of claims 1 to 3, wherein the polyvinyl acetal resin is a polyvinyl butyral resin.

6. The method for producing a resin laminate with a wiring pattern according to any one of claims 1 to 3, wherein a copper foil with a resin layer obtained by laminating the resin layer on one surface of a copper foil is used as the laminate.