JP2016178105A - Etchant composition and etching method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: an etchant composition which enables the etching of an indium oxide-based layer, and which can reduce the corrosion of titanium although it is an etchant composition containing hydrogen chloride; and an etching method with such an etching composition.SOLUTION: An etchant composition for an indium oxide-based layer according to the present invention consists of an aqueous solution comprising: (A) hydrogen chloride; and (B) at least one compound selected from a group consisting of diethylene triamine penta (methylenephosphonic acid) and a salt thereof, and ethylene diamine tetra(methylenephosphonic acid) and a salt thereof, provided that the concentration of (A) is 0.1-30 mass%, and that of (B) is 0.001-10 mass%.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an etching solution composition for etching an indium oxide-based layer and an etching method using the composition.

  In recent years, with the widespread use of smartphones, the demand for capacitive touch panels has increased, and accordingly, the demand for etching solutions for processing indium-based layers used in transparent conductive films has increased. Various techniques for wet etching of indium oxide-based layers used for transparent conductive films, etc. are known, but an aqueous solution containing hydrogen chloride is often used as an etchant composition because it is inexpensive and has a good etching rate. Has been.

  Patent Documents 1 and 2 disclose that an indium-tin oxide (hereinafter sometimes abbreviated as ITO) layer made of an etching agent containing hydrogen chloride, ferric chloride and phosphoric acid and a multilayer etching made of copper are used. The etchant used is disclosed.

JP 2009-235438 A JP 2008-547232 A

  Conventionally, titanium is sometimes used for materials such as containers, piping, and fasteners related to the etching process. In such a case, when an etching solution containing hydrogen chloride as described in Patent Documents 1 and 2 is used, titanium is corroded, and containers, piping, fasteners, and the like may be deteriorated. It was a problem. On the other hand, when the crystallized ITO is etched, an etching solution containing no hydrogen chloride has a problem that the etching time becomes very long and the productivity is remarkably lowered. Therefore, an etching solution containing hydrogen chloride in which corrosion of titanium is suppressed has been demanded.

  Accordingly, an object of the present invention is to provide an etching solution composition capable of etching an indium oxide-based layer and capable of reducing titanium corrosion while being an etching solution composition containing hydrogen chloride, and the etching method. An object of the present invention is to provide an etching method using the composition.

As a result of repeated studies, the present inventors have found that an etching solution composition having a specific component can solve the above problems, and have reached the present invention.
That is, the present invention contains (A) hydrogen chloride; (B) at least one compound selected from the group consisting of diethylenetriaminepenta (methylenephosphonic acid) and salts thereof and ethylenediaminetetra (methylenephosphonic acid) and salts thereof. An etching solution composition for an indium oxide-based layer, wherein the concentration of (A) is 0.1 to 30% by mass and the concentration of (B) is 0.001 to 10% by mass. It relates to things.

  Moreover, this invention relates to the etching method using the said etching liquid composition.

  According to the etching solution composition of the present invention, it is possible to etch an indium oxide-based layer, and it is possible to reduce corrosion of titanium even though it is an etching solution composition containing hydrogen chloride. Is.

It is a schematic diagram which shows the cross section of the board | substrate used as a test piece in Example 2 and Comparative Example 2. FIG.

Hereinafter, the etching solution composition of the present invention will be specifically described.
First, the “indium oxide-based layer” described in the present specification means a layer containing indium oxide and is not particularly limited. For example, an indium oxide layer, an indium-tin oxide layer In addition, it is a general term for a layer composed of one or more selected from an indium-gallium-zinc oxide layer and an indium-zinc oxide layer.

  The concentration of (A) hydrogen chloride [hereinafter sometimes abbreviated as component (A)] used in the etching solution composition of the present invention is 0.1 to 30% by mass. When the concentration of the component (A) is lower than 0.1% by mass, a sufficient etching rate cannot be obtained, which is not preferable. On the other hand, when the concentration of the component (A) is higher than 30% by mass, it is not preferable because it becomes difficult to control the etching rate. The concentration of the component (A) may be appropriately adjusted depending on the thickness and width of the indium oxide-based layer that is the material to be etched, but when the concentration of the component (A) is 1 to 20% by mass, High long-term storage stability is particularly preferred.

  (B) Diethylenetriaminepenta (methylenephosphonic acid) and a salt thereof and at least one compound selected from the group consisting of ethylenediaminetetra (methylenephosphonic acid) and a salt thereof used in the etching solution composition of the present invention [hereinafter referred to as (B In some cases, the salt of diethylenetriaminepenta (methylenephosphonic acid) and ethylenediaminetetra (methylenephosphonic acid) may be an alkali metal salt such as sodium salt, potassium salt or lithium salt, or alkaline earth such as magnesium salt. Metal salts. Among these, when diethylenetriaminepenta (methylenephosphonic acid) and a salt thereof are used, the effect of reducing the corrosion of titanium is particularly high and preferable. As the component (B), only one type of compound may be used, or two or more types of compounds may be used.

  (B) The density | concentration of a component is 0.001-10 mass%. When the concentration of the component (B) is lower than 0.001% by mass, the blending effect is not manifested, and when it exceeds 10% by mass, the blending effect is not improved, which is not desirable. . Note that the concentration of the component (B) may be appropriately adjusted depending on the thickness and width of the indium oxide-based layer that is the material to be etched, but when the concentration of the component (B) is 0.001 to 5% by mass, The effect of reducing the corrosion of the composition is high, and the long-term storage stability of the composition is particularly high, which is particularly preferable.

  In the etching solution composition of the present invention, the essential component other than the components (A) and (B) is water. Therefore, it is provided in the form of an aqueous solution containing a necessary amount of the above components.

  In addition to the above components (A) and (B), the etching solution composition of the present invention can be blended with known additives as long as the effects of the present invention are not impaired. Examples of the additive include an etchant composition stabilizer, a solubilizer for each component, an antifoaming agent, a pH adjuster, a specific gravity adjuster, a viscosity adjuster, a wettability improver, a chelating agent, an oxidizing agent, and a reduction agent. An agent, surfactant, etc. are mentioned, The density | concentration in the case of using these is generally the range of 0.001 mass%-10 mass%.

  In addition, when the etching rate of the etching solution composition of the present invention is too fast, it is preferable to use a reducing agent as an additive, specifically, copper chloride, ferrous chloride, copper powder, silver powder, and the like. The concentration when using is generally in the range of 0.01% to 10% by weight.

  When the substrate to be etched is a laminate including an indium oxide-based layer and a copper and / or copper alloy layer, the etching solution composition of the present invention selectively etches only the indium oxide-based layer from the substrate to be etched. Can do. The indium oxide-based layer may be a single layer or a laminate of two or more layers. The copper and / or copper alloy layer may be a single layer or a laminate of two or more layers. In the laminate including the indium oxide-based layer and the copper and / or copper alloy layer, the copper and / or copper alloy layer may be an upper layer or a lower layer of the indium oxide-based layer. There may be. In the laminate including the indium oxide-based layer and the copper and / or copper alloy layer, the indium oxide-based layer and the copper and / or copper alloy layer may be alternately stacked, and other metals may be used. The layer to contain may be pinched | interposed.

  Here, the “copper alloy layer” described in the present specification is not particularly limited, and examples thereof include a copper-nickel alloy, a copper-nickel-titanium (CuNiTi) alloy, and a silver-palladium-copper alloy. It is a generic term for a layer composed of one or more selected from representative copper alloys.

  The etching method for etching the indium oxide-based layer using the etching agent composition of the present invention is not particularly limited, and a well-known general etching method may be used. For example, there are dip type, spray type and spin type etching methods.

  For example, a Cu layer, a CuNiTi layer, and a photosensitive dry film resist layer are formed in order from the bottom on a substrate on which an ITO layer is formed on a polyethylene terephthalate (hereinafter sometimes abbreviated as PET) film by a dip etching method. In the case of etching a substrate formed with a pattern composed of the substrate, the base material is immersed in the etching agent of the present invention, and after being immersed under appropriate etching conditions, only the ITO layer is selectively etched from the base material. can do.

  The etching conditions are not particularly limited, and can be arbitrarily set according to the shape and film thickness of the etching target. For example, the etching temperature is preferably 10 ° C to 60 ° C, and particularly preferably 30 ° C to 50 ° C. Since the temperature of the etching agent may be increased by reaction heat, the temperature can be controlled by a known means so as to maintain it within the above temperature range if necessary. Further, the etching time is not particularly limited because it may be a time sufficient for the object to be etched to be completely etched. For example, if the etching target has a film thickness of about 10 to 10,000 mm as in the wiring manufacturing on the electronic circuit board, the etching can be performed for about 0.2 to 30 minutes within the above temperature range.

EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention in detail, it should be understood that this invention is not limited at all by these.
Example 1
Compositions 1 to 14 of the present invention were obtained by blending each component at the blending ratio shown in Table 1. The balance is water.

Comparative Example 1
Comparative product compositions 1 to 8 were obtained by blending each component at the blending ratio shown in Table 2. The balance is water.

Example 2
As shown in the schematic diagram of FIG. 1, a Cu layer (3), a copper-nickel alloy layer (hereinafter referred to as a CuNi layer and a CuNi layer) are formed in order from the bottom on a substrate on which an ITO layer (2) is formed on a PET film (1). A substrate on which a pattern (width 75 μm, opening 25 μm) composed of (4) and the photosensitive dry film resist layer (5) was formed was cut into a length of 20 mm × width of 20 mm to obtain a test piece. Etching by dipping using the etching composition of the product of the present invention prepared in Example 1 at 45 ° C. with stirring until no exposed ITO can be completely seen visually with respect to this test piece. By performing the treatment, only the ITO layer was selectively etched.

Comparative Example 2
For the same test piece as in Example 2, using the comparative etchant composition prepared in Comparative Example 1 at 45 ° C. under stirring until the exposed ITO is not completely visible. Only the ITO layer was selectively etched by performing a dip etching process.

Evaluation Example 1
About the pattern obtained by Example 2 and Comparative Example 2, the state of the pattern upper part was confirmed using the laser microscope. The state of the upper part of the pattern was evaluated by confirming the presence or absence of a chip having a length of 3 μm or more at the uppermost part of the pattern. Specifically, the case where a chip having a length of 3 μm or more was observed at the top of the pattern was evaluated as “X”, and the case where a chip having a length of 3 μm or more was not observed was rated as “◯”.

From the results of Table 3, it was found that Evaluation Examples 1-1 to 1-14 can be etched without occurrence of chipping with a length of 3 μm or more. On the other hand, in Comparative Example 2-7, it was found that a chip having a length of 3 μm or more occurred. Further, Comparative Example 2-8 could not even etch ITO.

Example 3
Titanium test pieces (weight: 5.55 to 5.65 g) having a length of 50 mm × width of 20 mm × thickness of 1 mm were impregnated in compositions 1 to 14 of the present invention in a thermostatic bath at 50 ° C. for 24 hours. Then, it was made to wash and dry and the titanium test pieces 1-14 for evaluation were obtained.

Comparative Example 3
The same titanium test piece (weight 5.55 to 5.65 g) as in Example 3 was impregnated in Comparative Product Compositions 1 to 8 in a thermostatic bath at 50 ° C. for 24 hours. Then, it was made to wash with water and dry and the titanium test pieces 1-8 for a comparison were obtained.

Evaluation example 2
With respect to the Ti test pieces 1 to 14 for evaluation and the titanium test pieces 1 to 6 for comparison, the weight change rate (L) between the weight before impregnation and the weight after impregnation was calculated. When L is small, there is little weight loss accompanying titanium corrosion, which is preferable.
The case where L is larger than 1 was evaluated as x, the case where it was in the range of 0.1 to 1, Δ, the case where it was less than 0.1 to 0.05 was evaluated as ◯, and the case where it was less than 0.05 was evaluated as ◎:
L = (weight before impregnation−weight after impregnation) / weight before impregnation × 100

  From the results of Table 4, it was found that in Evaluation Examples 2-1 to 2-14, L was less than 0.1 and there was little corrosion of titanium. Among these, it was found that evaluation examples 2-1 to 2-6, 2-13, and 2-14 have particularly little corrosion of titanium. On the other hand, it was found that Comparative Example 3-1 to Comparative Example 3-6 had a larger L than Evaluation Example 2-1 to Evaluation Example 2-14, and the amount of corrosion of titanium was large.

  The etching solution composition of the present invention can be suitably used mainly when processing electrodes and wirings such as liquid crystal displays, plasma displays, touch panels, organic EL, solar cells, and luminaires.

  1 PET film, 2 ITO layer, 3 Cu layer, 4 CuNi layer, 5 photosensitive dry film resist layer.

Claims (3)

(A) hydrogen chloride;
(B) an aqueous solution containing at least one compound selected from the group consisting of diethylenetriaminepenta (methylenephosphonic acid) and salts thereof and ethylenediaminetetra (methylenephosphonic acid) and salts thereof,
The concentration of (A) is 0.1 to 30% by mass,
(B) The density | concentration is 0.001-10 mass%, The etching liquid composition for indium oxide type layers characterized by the above-mentioned.   An etching method for etching an indium oxide-based layer, wherein the etching solution composition according to claim 1 is used.   The indium oxide-based layer is at least one layer selected from an indium oxide layer, an indium-tin oxide layer, an indium-gallium-zinc oxide layer, and an indium-zinc oxide layer. Etching method.

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