TW201839175A - Etching liquid composition and etching method - Google Patents

Abstract

Provided is an etching liquid composition for etching a nickel-containing layer, whereby a smooth layer surface after etching can be obtained, a large level difference between layers is not prone to occur even when a layered body of a nickel-containing layer and a metal-based layer is etched at once. The present invention is an etching liquid composition for etching a nickel-containing layer. An aqueous solution containing: (A) 0.1-20 mass% in terms of iron(II) ion concentration of an iron(II) ion component; (B) 0.01-20 mass% of hydrogen chloride; and (C) 0.01-5 mass% of at least one species selected from the group consisting of 5-aminotetrazole, benzothiazole, and benzotriazole.

Description

 Etching liquid composition and etching method  

The present invention relates to an etching liquid composition and an etching method using the same. More specifically, it relates to an etching liquid composition for etching a nickel-containing layer such as a constant-state steel such as Fe-Ni 36% or stainless steel, and an etching method using the same.

The nickel-containing layer is used for, for example, a printed wiring board, a lead frame, a precision electronic component such as TAB or BGA, and a high-definition display component such as a mask. Further, as a technique for performing microfabrication on a nickel-containing layer, a wet etching technique is known.

For example, the etching liquid disclosed in Patent Document 1 is an etching liquid for stainless steel which can improve adhesion to a material such as a resin, and contains an acid, an iron ion, a halide ion, an amphoteric surfactant, and a specific metal ion. .

Further, the etching liquid disclosed in Patent Document 2 is an etching liquid for a constant-van steel alloy, and contains: copper (II) chloride or ferric chloride, hydrochloric acid, a polyethylene glycol derivative, and, for example, a wax, an antirust oil. And other lipophilic hydrocarbons.

 [Previous Technical Literature]    [Patent Literature]  

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2017-014607

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2004-238666

However, when the etching liquids disclosed in Patent Documents 1 and 2 are used, a through hole is formed in the Fe-Ni 36% layer and the nickel-containing stainless steel layer by etching, and there is a problem that the through hole wall surface is not smooth. Further, when the through hole is formed by etching the layered body of the Fe-Ni 36% layer and the copper layer or the layered body of the stainless steel layer and the copper layer by using the etching liquid, the through hole wall surface is also smooth.

Furthermore, the etching rate of the Fe-Ni 36% layer and the copper layer is different. Therefore, the difference between the etching width of the Fe-Ni 36% layer in the direction parallel to the substrate surface and the etching width of the copper layer is widened, and a large gradient difference tends to occur between the Fe-Ni 36% layer and the copper layer. Further, in the case of the laminated body of the stainless steel layer and the copper layer, the difference between the etching width of the stainless steel layer and the etching width of the copper layer is enlarged due to the difference in the etching rate, and a large gradient difference easily occurs between the two layers. .

Therefore, the present invention has been made to solve the above problems, and an object thereof is to provide an etching liquid composition for etching a nickel-containing layer, which can smooth the surface of the layer after etching, and even if the nickel layer and the metal layer are integrated When the layered body of the layer is etched, a large gradient difference is unlikely to occur between the two layers. Further, an object of the present invention is to provide an etching method using the above etching liquid composition.

The present inventors have intensively studied to solve the above problems, and as a result, found that iron ion component, hydrogen chloride, and at least one compound selected from the group consisting of 5-aminotetrazole, benzothiazole, and benzotriazole are selected. The etchant composition of the aqueous solution can solve the above problems and complete the present invention.

That is, the etching liquid composition according to the present invention is an etching liquid composition for etching a nickel-containing layer, wherein: (A) the iron ion component is 0.1 to 20% by mass in terms of iron ion concentration; (B) hydrogen chloride 0.01 to 20% by mass; and (C) at least one compound selected from the group consisting of 5-aminotetrazole, benzothiazole and benzotriazole, 0.01 to 5% by mass; Etching liquid composition.

Further, the etching method (first etching method) according to the present invention includes the step of etching the nickel-containing layer provided on the substrate by using the etching liquid composition.

Furthermore, the etching method (second etching method) according to the present invention includes: using the etching liquid composition described above, and integrally performing a laminate including a nickel-containing layer and a metal-based layer disposed on the substrate The step of etching.

According to the present invention, there can be provided an etching liquid composition for etching a nickel-containing layer, which can smooth the surface of the layer after etching, and even if the laminated body of the nickel-containing layer and the metal-based layer is etched in an integrated manner, Large gradient differences are still less likely to occur between the two layers. Further, according to the present invention, an etching method using the above etching liquid composition can be provided.

Hereinafter, embodiments of the present invention will be specifically described. The "nickel-containing layer" in the present specification is not particularly limited as long as it is a layer containing nickel. The "nickel-containing layer" may be, for example, nickel; nickel oxide; Fe-Ni 36%, Fe-Ni 32%-Co 5%, Fe-Ni 29%-Co 17%, Fe-Ni 42%-Cr-Ti, Ni-Mo 28%- Fe2% and other alloys known as Hengfan Steel; SUS304, SUS304L, SUS321, SUS347, SUS316, SUS317, SUS890, NSSC170, NSSC270, SUS316N, NSSC316, SUS309S, SUS310S, AISI314, NSSC731, SUS304-M, SUS304-S, SUS- 304J3, SUSXM7, SUS305, SUS305J1, NSSC130M, NSSC131, SUS201, SUS302, SUS304N1, SUS304-H, SUS631J1, SUS303, SUS316F, SUS303Cu, NSSC140, SUS304-P, SUS304J3-P, SUS316-P, SUS316L-P, SUS304- Stainless steel such as HP, NSSC550, SUS329J1, NSSCDX1, SUS630, SUS631J1, etc. The nickel-containing layer which is the object to be etched of the etching liquid composition of the present invention is preferably the above-mentioned constant-van steel material or stainless steel.

The term "etching" as used herein refers to a shaping or surface processing technique performed by the corrosive action of a chemical or the like. Specific examples of the composition of the etching liquid composition of the present invention include a remover, a surface smoothing agent, a surface roughening agent, a pattern forming agent, and a cleaning solution for a trace amount of a component on a substrate. When the etching liquid composition of the present invention is used for forming a fine-shaped pattern having a three-dimensional structure, a pattern having a desired shape such as a rectangle can be obtained, and therefore it is suitably used as a medicine for pattern formation. Further, when the etching liquid composition of the present invention is used as an etchant for forming a through hole in, for example, a nickel-containing layer or a laminate of a nickel-containing layer and a metal-based layer, the surface of the layer after the treatment can be made smooth, and a laminated body can be formed. Since the double layer is less likely to have a large gradient difference, it is also suitable as a through hole forming agent.

The "metal layer" in the present specification is not particularly limited as long as it is a layer composed of a metal other than nickel. The "metal layer" is a metal layer such as copper, titanium, chromium, silver, molybdenum, aluminum, platinum, or palladium; and contains a group consisting of copper, titanium, chromium, silver, molybdenum, aluminum, platinum, and palladium. In the group, an alloy layer of two or more kinds of metals (for example, Ag-Pd-Cu or the like) is selected, and a general term for one or more layers is selected.

The "copper-based layer" in the present specification is not particularly limited as long as it is a layer containing copper. The "copper-based layer" is a copper alloy in which copper is combined with one or more metals selected from the group consisting of zinc, lead, tin, and aluminum, and a layer of at least one of the layers is selected. Specific examples of the "copper-based layer" include a conductive layer containing 10% by mass or more of copper.

The etching liquid composition of the present invention contains (A) an iron ion component (hereinafter also referred to as "(A) component"). The component (A) is a component constituting the main component of the etching liquid composition. The iron ion component is not particularly limited as long as it can supply iron ions to the etching liquid composition (or to form iron ions). Examples of the iron ion component include iron (III) chloride, iron (III) bromide, iron (III) iodide, iron (III) sulfate, iron (III) nitrate, and iron (III) acetate. These iron ion components may be anhydrate or a hydrate. Further, these iron ion components may be used in combination of two or more kinds. The component (A) is preferably iron (III) chloride.

The concentration of the component (A) in the etching liquid composition is 0.1 to 20% by mass, preferably 1 to 15% by mass, in terms of iron ion concentration. The concentration of the component (A) can be appropriately adjusted in accordance with the thickness and width of the nickel-containing layer or the like belonging to the material to be etched. When the concentration of the component (A) is less than 0.1% by mass in terms of the concentration of the iron ion, the etching rate is too slow and the productivity is lowered. On the other hand, when the concentration of the component (A) exceeds 20% by mass in terms of the iron ion concentration, the etching rate is too fast, and it is difficult to control the etching rate.

The etching liquid composition of the present invention contains (B) hydrogen chloride (hereinafter also referred to as "(B) component"). The component (B) is a component constituting the main component of the etching liquid composition. The concentration of the component (B) in the etching liquid composition is 0.01 to 20% by mass, preferably 0.1 to 15% by mass. The concentration of the component (B) can be appropriately adjusted in accordance with the thickness and width of the nickel-containing layer or the like belonging to the material to be etched. If the concentration of the component (B) is less than 0.01% by mass, the etching rate is too slow. On the other hand, even if the concentration of the component (B) exceeds 20% by mass, the etching rate cannot be increased any more, and there is a possibility that problems such as corrosion of the device member may occur.

The etching liquid composition of the present invention contains: (C) at least one compound selected from the group consisting of 5-aminotetrazole, benzothiazole, and benzotriazole (hereinafter also referred to as "(C) component) "). By using the component (C) in combination with the component (A) and the component (B), the surface of the nickel-containing layer after etching can be smoothed, and even if the laminate of the nickel-containing layer and the metal layer is collectively etched. It can still suppress large gradient differences between the two layers. Further, by using the component (C) in combination with the component (A) and the component (B), when the laminate of the nickel-containing layer and the metal layer is collectively etched to form a through-hole, the treated layer can be processed. The layer surface is smooth and can suppress a large gradient difference between the two layers.

The component (C) is preferably at least any one of benzothiazole and benzotriazole. When at least one of benzothiazole and benzotriazole is used as the component (C), when the laminated body including the nickel-containing layer and the metal-based layer is collectively etched to form a through-hole, the treated layer can be formed. The surface is smoother and the gradient difference between the two layers can be further reduced.

The concentration of the component (C) in the etching liquid composition is 0.01 to 5% by mass, preferably 0.1 to 2% by mass. The concentration of the component (C) can be appropriately adjusted in accordance with the thickness and width of the nickel-containing layer or the like belonging to the material to be etched. When the concentration of the component (C) is less than 0.01% by mass, the blending effect of the component (C) cannot be exhibited. On the other hand, even if the concentration of the component (C) exceeds 5% by mass, the blending effect of the component (C) is not improved.

The etching liquid composition of the present invention is an aqueous solution in which each component is dissolved in water. Therefore, the etching liquid composition of the present invention contains water as a solvent. The amount of water in the etching liquid composition is set to the remaining portions of the components (A), (B), and (C). In addition, when an additive or the like described later is contained in the etching liquid composition, the concentration of the component (A), the component (B), the component (C), the additive, and the like is added to the remaining portion. The water content in the etching liquid composition may be set to about 55 to 99% by mass.

In the etching liquid composition of the present invention, as the component (A), the component (B), the component (C), and other components other than water, a known additive may be blended in a range that does not impair the effects of the present invention. Examples of the additive include a stabilizer for an etching liquid composition, a solubilizing agent for each component, an antifoaming agent, a pH adjuster, a specific gravity adjusting agent, a viscosity adjusting agent, a wettability improving agent, a chelating agent, an oxidizing agent, and a reducing agent. , surfactants, etc. The concentration of these additives is generally in the range of 0.001 to 10% by mass, respectively.

Among the above additives, the surfactant is preferably a polyether compound. By using the polyether compound as a surfactant and blending it into the etching liquid composition, the effect of smoothing the surface of the layer after etching can be further enhanced. The polyether compound is preferably used in a polyether polyol compound containing a nitrogen atom in a main chain structure. By blending such a polyether polyol compound into the etching liquid composition, the effect of smoothing the surface of the layer after the etching treatment can be particularly enhanced. The molecular weight or number average molecular weight of the above polyether polyol compound is preferably from 100 to 5,000. Commercial products of a polyether polyol compound containing a nitrogen atom in the main chain structure include, for example, the following product names: ADEKA polyether BM-34, BM-42, BM-54, BM-402 (all of which are ADEKA) Company system); SBU-Polyol 0476, 0870, H309, H463 (all of which are manufactured by Sumitomo Bayer Polyurethane Co., Ltd.).

When the etching rate is fast, it is preferred to use a reducing agent as an additive. Specific examples of the reducing agent include copper chloride, ferrous chloride, copper powder, silver powder, and the like. The concentration of the reducing agents is generally in the range of 0.01 to 10% by mass.

The specific gravity of the composition of the etching solution of the present invention is usually in the range of 1.05 to 1.30, preferably in the range of 1.1 to 1.2. The "specific gravity" of the etching liquid composition in the present specification means the specific gravity measured by a known specific gravity measuring method. Specifically, the ratio of the mass of the 50 ° C etching liquid composition (the etching liquid composition mass/water mass) of the same volume of the 4 ° C water mass at a pressure of 101,325 Pa is the specific gravity of the etching liquid composition. For the method of measuring the specific gravity, for example, a method using a hydrometer such as a floating scale or a vibrating density specific gravity measuring device (for example, a product name "DA-650" (manufactured by Kyoto Electronics Co., Ltd.)) method.

The first etching method of the present invention includes the step of etching the nickel-containing layer provided on the substrate by using the etching liquid composition. Further, the second etching method of the present invention includes the step of etching the layered body containing the nickel-containing layer and the metal-based layer disposed on the substrate by using the etching liquid composition.

When the etching liquid composition of the present invention is used, the laminate containing the nickel-containing layer and the metal-based layer can be collectively etched. The nickel-containing layer disposed on the substrate may be a single layer or a laminate of two or more layers. Further, the nickel-containing layer and the metal-based layer which are provided on the substrate and which are provided with the laminate may be a single layer or two or more layers. The layered system disposed on the substrate may be disposed on the upper layer of the nickel-containing layer, or may be disposed on the lower layer, or may be disposed on both the upper layer and the lower layer. Further, a nickel-containing layer and a metal-based layer may be alternately laminated. Further, according to the etching method of the present invention, the laminated body including the nickel-containing layer and the metal-based layer is collectively etched to form a through hole. When such a through hole is formed, a preferred nickel-containing layer is the above-described constant-van steel and stainless steel, and a preferred metal-based layer is the copper-based layer.

The method of etching the nickel-containing layer disposed on the substrate and the method of etching the layered body including the nickel-containing layer and the metal-based layer disposed on the substrate are not particularly limited. Take a general etching method. For example, an etching method performed by an immersion type, a spray type, a rotary type or the like is used. Further, the etching liquid composition can be used in a general manner such as a batch type, a flow type, and an automatic control type using an oxidation-reduction potential, a specific gravity, or an acid concentration of an etchant.

For example, when a substrate having a laminate of a copper layer/Fe-Ni 36% layer/copper layer is disposed on a polyimide substrate by a spray etching method, the etching liquid composition is used. The laminate on the polyimide substrate can be etched by spraying the substrate under appropriate conditions. Also, a desired pattern can be formed by using a photomask.

The etching conditions are not particularly limited, and may be arbitrarily set in accordance with the shape and film thickness of the object to be etched. For example, the spray condition may be selected from the range of 0.01 to 1.0 MPa, preferably in the range of 0.1 to 0.5 MPa, and more preferably in the range of 0.15 to 0.4 MPa. Further, when the through hole is formed by the spray method, for example, by spraying the etching liquid composition in a spray pressure of 0.15 to 0.4 MPa, a through hole having a smoother wall surface can be formed, which is preferable.

The etching temperature is preferably set to 10 to 80 ° C, more preferably 20 to 70 ° C. The temperature of the etchant composition rises due to the heat of reaction. Therefore, in order to maintain the temperature of the etching liquid composition within the above range as needed, temperature control can be performed by a known means. Further, the etching time is not particularly limited as long as it is sufficient time for the etching to be completed. For example, if the material to be etched has a thickness of about 50 μm, etching may be performed for about 30 to 300 seconds in the above temperature range.

In the etching method of the present invention, in order to restore the performance of the etching liquid composition which is deteriorated by repeated etching, it is preferable to further include a step of adding a replenishing liquid to the etching liquid composition. For example, in the above-described automatic control type etching method, if a replenishing liquid is previously attached to the etching apparatus, a replenishing liquid can be added to the etching liquid composition. For the replenishing liquid, for example, an aqueous solution of at least one of the component (A), the component (B), and the component (C); an aqueous solution of the component (C); The concentration of each component in the aqueous solution (supplemental liquid) may be, for example, about 3 to 20 times the concentration of each component in the etching solution composition. Further, in the replenishing liquid, the etchant composition of the present invention may be added as an essential component or the respective components contained in an arbitrary component, as needed.

The etching liquid composition of the present invention and an etching method using the etching liquid composition are suitable for use in electrodes such as liquid crystal displays, plasma displays, touch panels, organic ELs, solar cells, lighting fixtures, etc., or When wiring is processed.

 [Examples]  

Hereinafter, the present invention will be described in detail by way of examples and comparative examples, but the invention is not limited thereto.

 <etching liquid composition>    (Examples 1 to 5)  

Each component was mixed so as to have the formulation shown in Table 1, and the etching liquid compositions of Examples Nos. 1 to 5 (Examples 1 to 5) were obtained. Further, water was blended in such a manner that the total amount of the components was 100% by mass.

 (Comparative examples 1 to 7)  

The components were mixed so as to have the formulations shown in Table 2, and the etching liquid compositions of Comparative Compositions 1 to 7 were obtained (Comparative Examples 1 to 7). Further, water was blended in such a manner that the total amount of the components was 100% by mass.

 <etching method (1)>    (Examples 6 to 10)  

A substrate in which a laminate of a copper layer A (thickness: 5 μm), a Fe-Ni 36% layer (thickness: 40 μm), and a copper layer B (thickness: 5 μm) was laminated on the polyimide substrate was prepared. On the copper layer B of the substrate, a photoresist pattern having an opening diameter (diameter) of 40 to 70 μm was formed using a negative dry film photoresist, and then cut into 40 mm × 40 mm to obtain a plurality of test pieces. With respect to the obtained test piece, the composition Nos. 1 to 5 were sprayed by a spray method under the conditions of a temperature of 50 ° C and a spray pressure of 0.2 MPa, and an etching treatment was performed to form a through hole. The etching treatment time is set to a time during which the through holes can be formed in accordance with each etching liquid composition.

 (Comparative examples 8 to 14)  

The through holes were formed in the same manner as in the above-described Examples 6 to 10 except that the comparative compositions 1 to 7 were used as the etching liquid composition.

 <etching method (2)>    (Example 11)  

A substrate in which a laminate of a copper layer C (thickness: 5 μm) and a SUS304 layer (thickness: 40 μm) was sequentially laminated on the polyimide substrate was prepared. On the SUS304 layer of the substrate, a photoresist pattern having an opening diameter (diameter) of 40 to 70 μm was formed using a negative dry film photoresist, and then cut into 40 mm × 40 mm to obtain a plurality of test pieces. With respect to the obtained test piece, the example composition No. 3 was sprayed by a spray method under the conditions of 50 ° C and a spray pressure of 0.2 MPa, and an etching treatment was performed to form a through hole. The etching treatment time is set to a time during which the through holes can be formed.

 (Comparative Example 15)  

A through hole was formed in the same manner as in the above-described Example 11, except that the comparative composition 1 was used as an etching liquid composition.

 <etching method (3)>    (Embodiment 12)  

On the polyimide substrate, a substrate in which a laminate of a copper layer D (thickness: 5 μm) and a SUS316 layer (thickness: 40 μm) was sequentially laminated was prepared. On the SUS316 layer of the substrate, a photoresist pattern having an opening diameter (diameter) of 40 to 70 μm was formed using a negative dry film photoresist, and then cut into 40 mm × 40 mm to obtain a plurality of test pieces. With respect to the obtained test piece, the composition of Example No. 3 was sprayed by a spray method under the conditions of 50 ° C and a spray pressure of 0.2 MPa, and an etching treatment was performed to form a through hole. The etching treatment time is set to a time during which the through holes can be formed.

 (Comparative Example 16)  

A through hole was formed in the same manner as in the above-described Example 12 except that the comparative composition 1 was used as the etching liquid composition.

 <evaluation>    (smoothness)  

The wall surface of the through-holes formed in Examples 6 to 12 and Comparative Examples 8 to 16 was observed using a laser microscope, and the evaluation of the smoothness was performed in accordance with the evaluation criteria described below. The results are shown in Table 3.

++: Smooth.

+: Fine unevenness can be confirmed.

-: A large bump can be clearly confirmed.

(degree of gradient difference (L ¹ and L ² ))

The gradient difference (L ¹ ) between the copper layer A and the Fe-Ni 36% layer and the Fe-Ni 36% layer and copper in the through holes formed in Examples 6 to 10 and Comparative Examples 8 to 14 were measured using a laser microscope. The gradient difference (L ² ) of the layer B was evaluated in accordance with the evaluation criteria shown below. Further, the gradient difference (L ¹ ) between the copper layer C and the SUS304 layer in the through holes formed in Example 11 and Comparative Example 15 was measured using a laser microscope, and the degree of the gradient difference was evaluated in accordance with the evaluation criteria described below. Further, the gradient difference (L ¹ ) between the copper layer D and the SUS316 layer in the through-holes formed in Example 12 and Comparative Example 16 was measured using a laser microscope, and the degree of the gradient difference was evaluated in accordance with the evaluation criteria described below. The results are shown in Table 3.

++: Less than 1 μm.

-: 1~5μm.

--: Greater than 5 μm.

As is apparent from the results shown in Table 3, the through-holes formed in Examples 6 to 12 had excellent wall smoothness and a small gradient difference (L ¹ and L ² ). On the other hand, it was found that the wall surfaces of the through holes formed in Comparative Examples 8 to 16 were all poor in smoothness, and the gradient differences (L ¹ and L ² ) were large. From the above, when the etching liquid composition of the present embodiment is used, the nickel-containing layer and the copper-based layer are collectively etched to form a smooth wall surface, and the nickel-containing layer and the copper-based layer are not subjected to a large gradient. Poor through hole.

Claims (5)

 An etching liquid composition for etching a nickel-containing layer, which comprises the following aqueous solutions (A) to (C), and (A) an iron ion component in terms of iron ion concentration: 0.1 ~20% by mass; (B) 0.01 to 20% by mass of hydrogen chloride; and (C) at least one compound selected from the group consisting of 5-aminotetrazole, benzothiazole and benzotriazole, 0.01 to 5 mass %.    The etching liquid composition of claim 1, further comprising a polyether polyol compound containing a nitrogen atom in the main chain structure.    The etching liquid composition according to claim 1 or 2, which is used for collectively etching a laminate including a nickel-containing layer and a metal-based layer.    An etching method comprising the step of etching a nickel-containing layer provided on a substrate using the etching liquid composition of claim 1 or 2.    An etching method comprising the step of etching the layered body containing the nickel-containing layer and the metal-based layer provided on the substrate in an integrated manner using the etching liquid composition of claim 3.