JP2023172703A - Cleaning method - Google Patents

Abstract

To provide a cleaning method which is excellent in resin mask removability.SOLUTION: A cleaning method includes a step of peeling a resin mask from an object to be cleaned to which a resin mask is attached using a detergent composition. The detergent composition is a detergent composition containing a quaternary ammonium hydroxide (component A), amino alcohol (component B), aromatic alcohol (component C), and water (component D). A mass ratio D/C of the component D to the component C in the detergent composition is less than 10. The object to be cleaned to which the resin mask is attached is a substrate having a cured resin mask on a surface having metal wiring having a line width of a thin line part of 5 μm or more and 35 μm or less and a thickness of a thickest part of 40 μm or more and 80 μm or less.SELECTED DRAWING: None

Description

The present disclosure relates to a cleaning method and a method of manufacturing electronic components using the same.

In recent years, personal computers and various electronic devices have become lower in power consumption, faster in processing speed, and smaller in size, and the wiring on package substrates and the like mounted on these devices is becoming smaller and smaller year by year. The metal mask method has been mainly used to form such fine wiring and connection terminals such as pillars and bumps, but it has become less versatile and difficult to respond to miniaturization of wiring etc. This is changing to other new methods.

As one of the new methods, a method is known in which a dry film resist is used as a thick film resin mask instead of a metal mask. This resin mask is finally peeled off and removed, and at this time an alkaline peeling cleaning agent is used.

As an alkaline peeling cleaning agent, for example, Patent Document 1 describes a dual-use cleaning agent that can simultaneously clean solder flux and dry film resist, with an amount of benzyl alcohol added of 5% to the total amount. 94% by weight, an amine compound in a range of 1 to 50% by weight, and a water content in a range of 3 to 90% by weight. ing. In the cleanability evaluation of the example in the same document, a dry film resist (film thickness 70 μm) was pasted on the surface of a silicon wafer, and an opening with a diameter of 150 μm was formed on the silicon wafer electrode by exposure and development. It is described that a test piece was used that was printed and filled with solder paste and reflowed at 250°C.
Furthermore, Patent Document 2 describes a cleaning agent composition containing 100% of a cleaning agent composition as a cleaning agent that can promote the removal of a resin mask layer after heat treatment of solder bumps and suppress solder corrosion, and can improve solder connection reliability. The part contains 0.5 parts by mass or more and 3.0 parts by mass or less of a specific quaternary ammonium hydroxide, 3.0 parts by mass or more and 10.0 parts by mass or less of a water-soluble amine, and an acid or its A cleaning agent composition for a resin mask layer is described, which contains an ammonium salt of 0.3 parts by mass or more and 2.5 parts by mass or less, and contains water of 50.0 parts by mass or more and 95.0 parts by mass or less. In the example of the same document, in manufacturing a circuit board on which solder bumps are formed, the circuit board used for forming the solder bumps has 3,600 copper surface electrodes with a diameter of 25 μm at a pitch of 50 μm per chip. , it is described that a circuit board was used in which the electrodes on the surface of the substrate were surrounded by a solder resist having a height of 15 μm, which was higher than the electrodes. Then, a resist film is pasted on the solder resist formed on the circuit board to form a resin mask layer, and openings are formed in the resin mask layer and the solder resist on the electrodes of the circuit board by exposure and development treatment. Solder paste and flux were applied, heated on a hot plate at 250°C for 1 minute, reflowed to form solder bumps on the electrodes of the circuit board, and the circuit board was cut into 1 cm square pieces to be used as test pieces. Are listed.
Patent Document 3 describes the use of quaternary ammonium hydroxides, alkali metal hydroxides, alkanolamines, specific sulfonic acid compounds, and specific aromatic compounds as resist stripping agents for removing the resist on color filter substrates. Resist stripper compositions containing group alcohols have been described.

Japanese Patent Application Publication No. 2007-224165 JP2015-79244A Japanese Patent Application Publication No. 2014-157339

When forming fine wiring on printed circuit boards, etc., cleaning agent compositions are used to reduce not only residual resin masks but also residual auxiliaries contained in solder and plating solutions used for fine wiring and bump formation. Objects need to be highly washable.
However, as wiring becomes finer, it is becoming more difficult to remove resin masks located in minute gaps, and cleaning compositions are required to have high resin mask removability.
On the other hand, in order to miniaturize electronic devices, increase processing speed, and reduce power consumption, interconnections are becoming increasingly finer. As the wiring width becomes narrower, electrical resistance increases, heat is generated, and there is a risk that the functionality of the electronic device will deteriorate. In order to reduce the electrical resistance without increasing the area of the wiring board, measures are taken to increase the height of the wiring. Therefore, the resin mask used for forming the wiring becomes thicker, increasing the contact area with the wiring, and furthermore, as the wiring interval becomes narrower due to miniaturization, the resin mask becomes difficult to remove. In particular, high-energy, low-wavelength light is used to draw fine wiring, but because the resin mask is thick, the distance from the resin mask surface to the substrate becomes long, and the reaction rate of photopolymerization due to exposure is lower than that of the surface. A difference occurs between the contact surface of the resin mask and the substrate, and the surface reaction progresses excessively, and unless the permeability is strengthened, the cleaning composition will not penetrate through the surface of the resin mask, making it difficult to remove the resin mask.

Therefore, the present disclosure provides a cleaning method that is excellent in removing a resin mask.

In one embodiment, the present disclosure includes a step of peeling off a resin mask from an object to be cleaned to which the resin mask is attached, using a cleaning composition, and the cleaning composition includes a quaternary ammonium hydroxide (component). A), a cleaning composition containing amino alcohol (component B), aromatic alcohol (component C), and water (component D), the mass ratio D of component D and component C in the cleaning composition. /C is less than 10, and the object to be cleaned to which the resin mask is attached is a surface of a substrate having metal wiring with a line width of 5 μm or more and 35 μm or less in the thin line portion and a thickness of 40 μm or more and 80 μm or less at the thickest portion. The present invention relates to a method of cleaning a substrate having a cured resin mask.

In one aspect, the present disclosure relates to a method for manufacturing an electronic component, including a step of cleaning an electronic circuit board having a resin mask using the cleaning method of the present disclosure.

According to the present disclosure, a cleaning method with excellent resin mask removability can be provided.

FIG. 1A is a photograph showing an example of the appearance of a substrate to be cleaned, and FIG. 1B is a photograph showing an example of the appearance of the substrate surface after cleaning using the cleaning compositions of Examples 1 to 4. 1C is a photograph showing an example of the appearance of the substrate surface after cleaning using the cleaning compositions of Comparative Examples 1 to 3.

The present disclosure is based on the finding that a resin mask can be efficiently removed from a substrate surface by using a cleaning composition containing a specific alkaline compound and further containing water and aromatic alcohol in a specific mass ratio.

In one embodiment, the present disclosure includes a step of peeling off a resin mask from an object to be cleaned to which the resin mask is attached, using a cleaning composition, and the cleaning composition includes a quaternary ammonium hydroxide (component). A), an amino alcohol (component B), an aromatic alcohol (component C), and a cleaning composition (hereinafter also referred to as "the cleaning composition of the present disclosure") containing water (component D); The mass ratio D/C of component D and component C in the agent composition is less than 10, and the object to be cleaned to which the resin mask is attached has a line width of 5 μm or more and a line width of 35 μm or less in the thin line portion, and a thickness of the thickest portion. The present invention relates to a cleaning method (hereinafter also referred to as "cleaning method of the present disclosure") in which a substrate has a hardened resin mask on the surface of a substrate having metal wiring with a diameter of 40 μm or more and 80 μm or less.

According to the present disclosure, a cleaning method with excellent resin mask removability can be provided. By using the cleaning method of the present disclosure for cleaning electronic components such as electronic circuit boards having resin masks, high-quality electronic components can be obtained with a high yield.

Although the details of the mechanism of action of the present disclosure are unclear, it is presumed as follows.
The quaternary ammonium hydroxide (component A) and the amino alcohol (component B) penetrate into the resin mask and promote the dissociation of the alkali-soluble resin contained in the resin mask, and further repel the charge generated by the dissociation. It is thought that this causes peeling of the resin mask. Since the quaternary ammonium hydroxide (component A) and the amino alcohol (component B) have different penetration speeds into the resin mask, the alkali-soluble resin on the surface of the resin mask is suppressed from rapidly dissociating, and the penetration speed is different. It is thought that charge repulsion only on the surface of the resin mask, which would be a hindrance, is suppressed.
On the other hand, the aromatic alcohol (component C) penetrates into the resin mask together with the quaternary ammonium hydroxide (component A) and the amino alcohol (component B), promoting penetration and further improving the releasability of the alkali-soluble resin. It is thought to promote this. In addition, when the ratio (mass ratio D/C) of water (component D) to aromatic alcohol (component C) is lowered, it becomes difficult for the aromatic alcohol (component C) to dissolve in the cleaning agent, and it becomes difficult to dissolve the aromatic alcohol (component C) into the alkali-soluble resin. It is thought that this will dramatically increase the likelihood of penetration.
However, the present disclosure does not need to be interpreted as being limited to this mechanism.

In the present disclosure, a resin mask is a mask for protecting a material surface from treatments such as etching, plating, and heating, that is, a mask that functions as a protective film.
In one or more embodiments, the resin mask includes a resist layer after exposure and development, and is subjected to at least one of exposure and development (hereinafter also referred to as "exposed and/or developed"). Examples include a resist layer or a hardened resist layer.
Further, in one or more embodiments, the resin mask is formed using a resist whose physical properties such as solubility in a developer change depending on light, electron beam, or the like. Resists are broadly divided into negative-type and positive-type resists based on the way they react with light and electron beams. A negative resist has the property that its solubility in a developer decreases when it is exposed to light, and a layer containing a negative resist (hereinafter also referred to as a "negative resist layer") has a property that the exposed area decreases after exposure and development processing. Used as a resin mask. A positive resist has the property that its solubility in a developing solution increases when exposed to light, and a layer containing a positive resist (hereinafter also referred to as a "positive resist layer") has a structure in which the exposed area remains after exposure and development processing. The unexposed area is used as a resin mask. By using a resin mask having such characteristics, fine connections on circuit boards such as metal wiring, metal pillars, and solder bumps can be formed.
In one or more embodiments, examples of the resin material forming the resin mask include a film-like photosensitive resin, a resist film, and a photoresist. A general-purpose resist film can be used.

[Peeling process]
The cleaning method of the present disclosure includes a step of peeling off the resin mask from an object to be cleaned to which the resin mask is attached (hereinafter also simply referred to as a "peeling step") using the cleaning composition of the present disclosure. In one or more embodiments, the peeling step includes bringing the object to be cleaned to which the resin mask is attached into contact with the cleaning composition of the present disclosure. According to the cleaning method of the present disclosure, the resin mask can be efficiently removed.

A method of peeling off a resin mask from an object to be cleaned using the cleaning composition of the present disclosure or a method of contacting the cleaning composition of the present disclosure with an object to be cleaned includes, for example, Examples include a method of contacting the product by immersing it in a cleaning bath, a method of contacting the product by spraying a cleaning composition (shower method), and an ultrasonic cleaning method of irradiating it with ultrasonic waves during immersion. The cleaning composition of the present disclosure can be used for cleaning as is without being diluted. Examples of the object to be cleaned include the objects to be cleaned described above. The immersion time may be, for example, 1 minute or more and 10 minutes or less, and more preferably 3 minutes or more and 6 minutes or less. Examples of the spray time include 1 minute or more and 10 minutes or less, and further 3 minutes or more and 6 minutes or less.

In one or more embodiments, the cleaning method of the present disclosure can include the steps of bringing the object to be cleaned into contact with the cleaning agent composition, rinsing with water, and drying. Examples of the rinsing method include rinsing with running water. Examples of the drying method include air blow drying.
In one or more embodiments, the cleaning method of the present disclosure can include a step of bringing the object to be cleaned into contact with the cleaning agent composition and then rinsing with water.

In the cleaning method of the present disclosure, it is preferable to irradiate ultrasonic waves when the cleaning composition of the present disclosure contacts the object to be cleaned, since the cleaning power of the cleaning composition of the present disclosure is likely to be exhibited. More preferably, the sound waves have a relatively high frequency. From the same viewpoint, the ultrasonic irradiation conditions are preferably, for example, 26 to 72 kHz and 80 to 1500 W, and more preferably 36 to 72 kHz and 80 to 1500 W.

In the cleaning method of the present disclosure, the temperature of the cleaning composition of the present disclosure is preferably 40°C or higher, more preferably 50°C or higher, in order to easily exhibit the cleaning power of the cleaning composition of the present disclosure, and From the viewpoint of reducing the influence on the temperature, the temperature is preferably 70°C or lower, more preferably 60°C or lower.

[Object to be cleaned]
Examples of the objects to be cleaned include electronic components and their manufacturing intermediates. Examples of the electronic component include at least one component selected from printed circuit boards, wafers, and metal plates such as copper plates and aluminum plates. The manufacturing intermediate is an intermediate product in the manufacturing process of electronic components, and includes an intermediate product after resin mask processing.
In one or more embodiments, the object to be cleaned to which the resin mask is attached includes an electronic circuit board having a cured resin mask.
In one or more embodiments, the object to be cleaned to which the resin mask is attached is the surface of a substrate having metal wiring with a line width of 5 μm or more and 35 μm or less at the thin line portion and a thickness of 40 μm or more and 80 μm or less at the thickest portion. A substrate having a cured resin mask can be mentioned. Examples of the substrate include a glass epoxy multilayer substrate. Examples of the metal wiring include metal foil such as copper foil. The metal foil may be formed by plating. In one or more embodiments, the substrate having metal wiring is a glass epoxy multilayer substrate having metal foil (for example, copper foil) on the surface. The line width of the thin line portion of the metal wiring is 5 μm or more, preferably 10 μm or more, from the viewpoint of removability of the cured resin mask, and from the same viewpoint, 35 μm or less, preferably It is 30 μm or less, more preferably 20 μm or less. The thickness of the thickest part of the metal wiring (thickness of the thin line part) is 40 μm or more, preferably 45 μm or more, from the viewpoint of removability of the cured resin mask, and from the same viewpoint, 80 μm It is preferably 75 μm or less, more preferably 70 μm or less, and even more preferably 65 μm or less.
In one or more embodiments, the object to be cleaned with the resin mask attached may be cleaned by undergoing a process such as soldering or plating (copper plating, aluminum plating, nickel plating, etc.) using a resin mask. Examples include electronic components in which wiring, connection terminals, etc. are formed on the surface of a substrate. Specifically, for example, an uncured resin mask on the surface of a glass epoxy multilayer board is subjected to at least one of exposure and development, and after the uncured resin mask is removed, a circuit pattern is formed by plating. Examples include substrates that are A hardened resin mask exists in the non-plated portion of the formed circuit pattern. Generally, the width of a cured resin mask adjacent to a thin line portion of a circuit pattern is formed to have the same width as the line width of the thin line portion. The width of the thin line portion formed by plating is preferably 5 μm or more, more preferably 10 μm or more, and preferably 35 μm or less, more preferably 30 μm or less, and even more preferably 20 μm or less, from the viewpoint of removability of the cured resin mask. It is. The thickness of the thin wire portion (plating thickness) by plating is preferably 40 μm or more, more preferably 45 μm or more, from the viewpoint of removability of the cured resin mask, and from the same viewpoint, preferably 80 μm or less, more preferably is 75 μm or less, more preferably 70 μm or less, even more preferably 65 μm or less. The width of the cured resin mask in the non-plated part (between the circuit patterns) is preferably 5 μm or more, more preferably 10 μm or more, and more preferably 35 μm or less, more preferably from the viewpoint of removability of the cured resin mask. is 30 μm or less, more preferably 20 μm or less. Further, electronic components include substrates having a resin on the surface from the viewpoint of exhibiting the effect of suppressing damage to the substrate resin, such as a substrate having a solder resist. Accordingly, the present disclosure relates in one aspect to the use of the cleaning compositions of the present disclosure as cleaning agents in the manufacture of electronic components.

In one or more embodiments, the cleaning method of the present disclosure is preferably used for cleaning a resin mask or an object to be cleaned to which a resin mask that has been further plated and/or heat-treated is attached, in terms of cleaning effects. It can be done. The resin mask may be, for example, a negative-type resin mask or a positive-type resin mask, and a negative-type resin mask is preferable since the effects of the present disclosure are easily exhibited. Examples of the negative resin mask include negative dry film resists that have been exposed and/or developed. In the present disclosure, a negative resin mask is formed using a negative resist, and includes, for example, a negative resist layer that has been exposed and/or developed. In the present disclosure, a positive resin mask is formed using a positive resist, and includes, for example, a positive resist layer that has been exposed and/or developed.

[Cleaning composition]
In one or more embodiments, the cleaning composition of the present disclosure is a cleaning composition containing the following component A, the following component B, the following component C, and the following component D. By using the cleaning composition of the present disclosure for cleaning an object to be cleaned to which a resin mask is attached, the resin mask can be efficiently removed. By using the cleaning composition of the present disclosure for cleaning electronic components such as electronic circuit boards having resin masks, high-quality electronic components can be obtained with high yield.
In one or more embodiments, the cleaning composition of the present disclosure can be used to clean an object to be cleaned to which a resin mask is attached. In one or more embodiments, the cleaning composition of the present disclosure can be used to peel off a resin mask from an object to be cleaned to which the resin mask is attached. That is, in one aspect, the present disclosure relates to the use of the cleaning composition of the present disclosure for peeling off a resin mask from an object to be cleaned to which the resin mask is attached.

(Component A: Quaternary ammonium hydroxide)
Examples of the quaternary ammonium hydroxide (hereinafter also referred to as "component A") included in the cleaning composition of the present disclosure include a quaternary ammonium hydroxide represented by the following formula (I). It will be done. Component A may be used alone or in combination of two or more.

In the above formula (I), R ¹ , R ² , R ³ and R ⁴ are each independently at least one member selected from a methyl group, an ethyl group, a propyl group, a hydroxymethyl group, a hydroxyethyl group and a hydroxypropyl group. It is.

The quaternary ammonium hydroxide represented by formula (I) is a salt consisting of a quaternary ammonium cation and a hydroxide, such as tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide, tetrapropyl Ammonium hydroxide, 2-hydroxyethyltrimethylammonium hydroxide (choline), 2-hydroxyethyltriethylammonium hydroxide, 2-hydroxyethyltripropylammonium hydroxide, 2-hydroxypropyltrimethylammonium hydroxide, 2-hydroxypropyltriethylammonium Hydroxide, 2-hydroxypropyltripropylammonium hydroxide, dimethylbis(2-hydroxyethyl)ammonium hydroxide, diethylbis(2-hydroxyethyl)ammonium hydroxide, dipropylbis(2-hydroxyethyl)ammonium hydroxide, tris(2-hydroxyethyl)ammonium hydroxide, -hydroxyethyl)methylammonium hydroxide, tris(2-hydroxyethyl)ethylammonium hydroxide, tris(2-hydroxyethyl)propylammonium hydroxide, tetrakis(2-hydroxyethyl)ammonium hydroxide, and tetrakis(2-hydroxyethyl)ammonium hydroxide. At least one selected from ammonium hydroxide (propyl) is mentioned. Among these, tetramethylammonium hydroxide (TMAH) is more preferred from the viewpoint of improving resin mask removability.

The content of component A when using the cleaning composition of the present disclosure is preferably 2% by mass or more, more preferably 2.5% by mass or more, from the viewpoint of improving resin mask removability, and from the same viewpoint , is preferably 5% by mass or less, more preferably 4% by mass or less, and even more preferably 3% by mass or less. From the same viewpoint, the content of component A when using the cleaning composition of the present disclosure is preferably 2% by mass or more and 5% by mass or less, more preferably 2% by mass or more and 4% by mass or less, and 2% by mass or more. More preferably, it is 3% by mass or less. When component A is a combination of two or more types, the content of component A refers to their total content.

In the present disclosure, "the content of each component at the time of use of the cleaning composition" refers to the content of each component at the time of cleaning, that is, at the time when the cleaning composition starts to be used for cleaning.
The content of each component in the cleaning composition of the present disclosure can be considered as the blending amount of each component in the cleaning composition of the present disclosure in one or more embodiments.

(Component B: amino alcohol)
Examples of the amino alcohol (alkanolamine) (hereinafter also referred to as "component B") included in the cleaning composition of the present disclosure include a compound represented by the following formula (II). Component B may be used alone or in combination of two or more.

In the above formula (II), R ⁵ represents a hydrogen atom, a methyl group, an ethyl group, or an aminoethyl group, R ⁶ represents a hydrogen atom, a hydroxyethyl group, a hydroxypropyl group, a methyl group, or an ethyl group, and R ⁷ represents a hydroxyethyl group or a hydroxypropyl group.

Component B includes, for example, monoethanolamine (MEA), monoisopropanolamine, N-methylmonoethanolamine, N-methylisopropanolamine, N-ethylmonoethanolamine, N-ethylisopropanolamine, diethanolamine, diisopropanolamine, N-dimethylmonoethanolamine, N-dimethylmonoisopropanolamine, N-methyldiethanolamine, N-methyldiisopropanolamine, N-diethylmonoethanolamine, N-diethylmonoisopropanolamine, N-ethyldiethanolamine, N-ethyldiisopropanol At least one selected from amine, N-(β-aminoethyl)ethanolamine, N-(β-aminoethyl)isopropanolamine, N-(β-aminoethyl)diethanolamine, N-(β-aminoethyl)diisopropanolamine Examples include seeds. Among these, monoethanolamine (MEA) is preferred from the viewpoint of improving resin mask removability.

The content of component B when using the cleaning composition of the present disclosure is preferably 5% by mass or more, more preferably 9% by mass or more, and even more preferably 10% by mass or more, from the viewpoint of improving resin mask removability. It is more preferably 11% by mass or more, and from the same viewpoint, it is preferably 15% by mass or less, more preferably 14% by mass or less, and even more preferably 13% by mass or less. From the same viewpoint, the content of component B when using the cleaning composition of the present disclosure is preferably 5% by mass or more and 15% by mass or less, more preferably 9% by mass or more and 15% by mass or less, and 10% by mass or more. It is more preferably 14% by mass or less, and even more preferably 11% by mass or more and 13% by mass or less. When component B is a combination of two or more types, the content of component B refers to their total content.

The total content of component A and component B when using the cleaning composition of the present disclosure is preferably 7% by mass or more, more preferably 8% by mass or more, and 9% by mass from the viewpoint of improving resin mask removability. The above is more preferable, 12% by weight or more is even more preferable, and from the same viewpoint, 20% by weight or less is preferable, more preferably 18% by weight or less, and even more preferably 15% by weight or less. From the same viewpoint, the total content of component A and component B when using the cleaning composition of the present disclosure is preferably 7% by mass or more and 20% by mass or less, more preferably 8% by mass or more and 18% by mass or less. , more preferably 9% by mass or more and 18% by mass or less, and even more preferably 12% by mass or more and 15% by mass or less.

(Component C: aromatic alcohol)
The aromatic alcohol (hereinafter also referred to as "component C") contained in the cleaning composition of the present disclosure may be any compound having an aromatic ring and a hydroxyl group. From the viewpoint of improving resin mask removability, the number of carbon atoms in the aromatic alcohol is preferably 7 or more, preferably 10 or less, and more preferably 9 or less. Component C may be used alone or in combination of two or more.

Component C includes at least one selected from benzyl alcohol, phenethyl alcohol, 4-methylbenzyl alcohol, 4-ethylbenzyl alcohol, 2-phenyl-1-propanol, and 2-phenyl-2-propanol; From the viewpoint of improving mask removability, benzyl alcohol is more preferred.

The content of component C during use of the cleaning composition of the present disclosure is preferably 5% by mass or more, more preferably 6% by mass or more, even more preferably 7% by mass or more, from the viewpoint of improving resin mask removability. From the viewpoint of suppressing damage to the substrate resin, the content is preferably 15% by mass or less, more preferably 13% by mass or less, and even more preferably 11% by mass or less. From the viewpoint of improving resin mask removability and suppressing damage to the substrate resin, the content of component C in the cleaning composition of the present disclosure is preferably 5% by mass or more and 15% by mass or less, and 6% by mass or more and 13% by mass or less. More preferably, it is 7% by mass or more and 11% by mass or less. When component C is a combination of two or more types, the content of component C refers to their total content.

(Component D: water)
In one or more embodiments, the water contained in the cleaning composition of the present disclosure (hereinafter also referred to as "component D") includes ion exchange water, RO water, distilled water, pure water, ultrapure water, etc. Can be mentioned.

The content of component D in the cleaning composition of the present disclosure can be the remainder after removing component A, component B, component C, and optional components described below. Specifically, the content of component D when using the cleaning composition of the present disclosure is preferably 45% by mass or more from the viewpoint of improving resin mask removability, reducing wastewater treatment load, and suppressing damage to the substrate resin. , more preferably 50% by mass or more, still more preferably 55% by mass or more, and from the viewpoint of improving resin mask removability, 80% by mass or less, more preferably 75% by mass or less, even more preferably 70% by mass or less. . From the same viewpoint, the content of component D when using the cleaning composition of the present disclosure is preferably 45% by mass or more and 80% by mass or less, more preferably 50% by mass or more and 75% by mass or less, and 55% by mass or more. More preferably, it is 70% by mass or less.

The mass ratio D/C of component D and component C when using the cleaning composition of the present disclosure is less than 10 and 9.5 or less, from the viewpoint of improving resin mask removability and suppressing damage to the substrate resin. is preferable, 9 or less is more preferable, and from the same viewpoint, it is 1 or more, preferably 5 or more, and more preferably 7 or more. From the same viewpoint, in one or more embodiments, the mass ratio D/C in the cleaning composition of the present disclosure is preferably 1 or more and less than 10, more preferably 5 or more and 9.5 or less, and 7 or more and 9 or less. More preferred.

(Component E: organic solvent)
The cleaning composition of the present disclosure may further contain an organic solvent (hereinafter also referred to as "component E") in one or more embodiments. Component E may be used alone or in combination of two or more.
In one or more embodiments, component E includes at least one organic solvent selected from glycol ethers and aromatic ketones.
Examples of the glycol ether include compounds having a structure in which 1 to 3 moles of ethylene glycol are added to an alcohol having 1 to 8 carbon atoms, from the viewpoint of improving the removability of the resin mask. Specific examples of glycol ether include at least one selected from diethylene glycol monobutyl ether (BDG), ethylene glycol monobenzyl ether, diethylene glycol monohexyl ether, ethylene glycol monophenyl ether, and diethylene glycol diethyl ether.
Examples of the aromatic ketone include acetophenone and the like from the viewpoint of improving the removability of the resin mask.

When the cleaning composition of the present disclosure contains component E, the content of component E during use of the cleaning composition of the present disclosure is preferably 0.1% by mass or more from the viewpoint of improving resin mask removability. , more preferably 0.5% by mass or more, still more preferably 1% by mass or more, even more preferably 2% by mass or more, and from the viewpoint of improving the removability of the resin mask, preferably 10% by mass or less, and 7% by mass or less. is more preferable, 5% by mass or less is even more preferable, and even more preferably 4% by weight or less. From the same viewpoint, the content of component E when using the cleaning composition of the present disclosure is preferably 0.1% by mass or more and 10% by mass or less, more preferably 0.5% by mass or more and 7% by mass or less, It is more preferably 1% by mass or more and 5% by mass or less, even more preferably 2% by mass or more and 4% by mass or less. When component E is a combination of two or more types, the content of component E refers to their total content.

(Other ingredients)
In addition to the components A to E, the cleaning composition of the present disclosure may further contain other components as necessary. Other components include components that can be used in ordinary cleaning agents, such as alkaline agents other than component A and component B, amines other than component B, surfactants, chelating agents, thickeners, Examples include dispersants, rust preventives, polymer compounds, solubilizers, antioxidants, preservatives, antifoaming agents, antibacterial agents, and the like.

In one or more embodiments, the cleaning composition of the present disclosure can be substantially free of acid or ammonium salt thereof. The content of the acid or its ammonium salt when using the cleaning composition of the present disclosure includes, for example, less than 0.3% by mass.

The pH during use of the cleaning composition of the present disclosure is preferably 12 or higher, more preferably 12.5 or higher, and even more preferably 13 or higher, from the viewpoint of improving resin mask removability. In the present disclosure, "pH during use" is pH at 25° C., and can be measured using a pH meter. Specifically, it can be measured by the method described in Examples.

(Method for manufacturing cleaning composition)
In one or more embodiments, the cleaning composition of the present disclosure can be produced by blending the components A to D and, if necessary, the optional components (component E and other components) described above by a known method. . For example, the cleaning composition of the present disclosure can contain at least the components A to D described above. Therefore, the present disclosure relates to a method for producing a cleaning composition, which includes at least the step of blending the components A to D. In the present disclosure, "blending" includes mixing components A to D and, if necessary, any of the above-mentioned optional components simultaneously or in any order. In the method for manufacturing the cleaning composition of the present disclosure, the preferred blending amount of each component can be the same as the preferred content of each component of the cleaning composition of the present disclosure described above.

The cleaning composition of the present disclosure may be prepared as a concentrate in which the amount of water (component D) is reduced within a range that does not cause separation, precipitation, etc. and impair storage stability. From the viewpoint of transportation and storage, the concentrate of the cleaning composition is preferably a concentrate with a dilution rate of 3 times or more, and from the viewpoint of storage stability, it is preferably a concentrate with a dilution rate of 30 times or less. . The concentrate of the cleaning composition can be used by diluting it with water (component D) so that the components A to D and optional components have the above-mentioned contents (that is, the contents at the time of cleaning). Furthermore, the concentrate of the cleaning composition can also be used by adding each component separately at the time of use. In the present disclosure, "at the time of use" or "at the time of cleaning" of a concentrated cleaning composition refers to a state in which the concentrated cleaning composition is diluted.

[Manufacturing method of electronic components]
In one aspect, the present disclosure relates to a method for manufacturing an electronic component, including a step of peeling a resin mask from an object to be cleaned to which the resin mask is attached (peeling step) using the cleaning method of the present disclosure. Examples of the object to be cleaned include the objects to be cleaned described above.
In another aspect, the present disclosure relates to a method for manufacturing an electronic component, including a step of cleaning an electronic circuit board having a resin mask (hereinafter also referred to as a "cleaning step") using the cleaning composition of the present disclosure. . Examples of the cleaning method in the cleaning step include the same methods as the cleaning method of the present disclosure described above.
According to the method for manufacturing an electronic component of the present disclosure, it is possible to effectively remove the resin mask attached to the electronic component, thereby making it possible to manufacture a highly reliable electronic component. Furthermore, by performing the cleaning method of the present disclosure, the resin mask attached to the electronic component can be easily peeled off, so that the cleaning time can be shortened and the manufacturing efficiency of the electronic component can be improved.

[kit]
In one aspect, the present disclosure relates to a kit for use in either the cleaning method of the present disclosure or the electronic component manufacturing method of the present disclosure (hereinafter also referred to as "the kit of the present disclosure"). In one or more embodiments, the kit of the present disclosure is a kit for producing the cleaning composition of the present disclosure. According to the kit of the present disclosure, a cleaning composition having excellent resin mask removability can be obtained.

An embodiment of the kit of the present disclosure includes a solution containing component A (first solution), a solution containing component B (second solution), and a solution containing component C (third solution). , in a mutually unmixed state, at least one selected from the first liquid, the second liquid and the third liquid further contains part or all of component D (water), and the first liquid and the second liquid Examples of the third liquid include a kit (three-component cleaning composition) that is mixed at the time of use. After the first liquid, second liquid, and third liquid are mixed, they may be diluted with water (component D) if necessary. Each of the first liquid, second liquid, and third liquid may contain the above-mentioned optional components as necessary.
Other embodiments of the kit of the present disclosure include a solution containing component A and component B (first solution) and a solution containing component C (second solution) in a state that they are not mixed with each other, At least one of the first liquid and the second liquid further contains part or all of component D (water), and the first liquid and the second liquid are mixed at the time of use. things). After the first liquid and the second liquid are mixed, they may be diluted with component D (water) as necessary. Each of the first liquid and the second liquid may contain the above-mentioned optional components as necessary.

EXAMPLES The present disclosure will be specifically explained below with reference to Examples, but the present disclosure is not limited to these Examples in any way.

1. Preparation of cleaning compositions of Examples 1 to 4 and Comparative Examples 1 to 3 Each component shown in Table 1 is blended in the amount (mass%, effective content) shown in Table 1, and the mixture is stirred. In this manner, cleaning compositions of Examples 1 to 4 and Comparative Examples 1 to 3 were prepared.
The pH at 25°C of each cleaning composition shown in Table 1 is a value measured using a pH meter (Toa Denpa Kogyo Co., Ltd., HM-30G), and the pH of the pH meter was immersed in the cleaning composition. This is the value after 1 minute.

The following were used to prepare the cleaning compositions of Examples 1 to 4 and Comparative Examples 1 to 3.
(Component A)
TMAH: Tetramethylammonium hydroxide [manufactured by Showa Denko K.K., concentration 25%]
(Component B)
MEA: Monoethanolamine [manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., special grade]
(Component C)
Benzyl alcohol [manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., special grade]
(Component D)
Water [Pure water of 1 μS/cm or less produced with the pure water device G-10DSTSET manufactured by Organo Co., Ltd.]
(Component E)
BDG: Butyl diglycol [manufactured by Nippon Nyukazai Co., Ltd., diethylene glycol monobutyl ether]

2. Evaluation of the cleaning compositions of Examples 1 to 4 and Comparative Examples 1 to 3 The cleaning compositions of Examples 1 to 4 and Comparative Examples 1 to 3 prepared were evaluated as follows.

[Test piece]
The test piece has a size of 120 mm x 120 mm, and has a thin line circuit pattern (thin line part) formed by copper plating on the surface of a glass epoxy multilayer board, and a resin mask that is a cured negative dry film resist between the formed thin line circuit patterns. The line width of the thin line circuit pattern (thin line portion) is 16 μm, and the thickness of the thin line portion (plating thickness) is 54 μm.

[Cleaning test method]
Perform the dip and shower in succession as follows. 1 kg of each of the cleaning compositions of Examples 1 to 4 and Comparative Examples 1 to 4 was added to a 1 L glass beaker, heated to 50°C, and heated using a rotor (fluororesin (PTFE), φ8 mm x 25 mm). The test piece is immersed for 5 minutes while stirring at a rotational speed of 300 rpm. A separately prepared 10 L stainless steel beaker is used as a storage tank, and 10 kg of the same detergent composition as in the 1 L glass beaker is added and heated to 50°C. Then, using a box-type spray cleaning machine equipped with a one-fluid nozzle (fan-shaped) VVP9060 (manufactured by Ikeuchi Co., Ltd.) as a spray nozzle, the cleaning composition in the storage tank was sprayed onto the test piece for 3 minutes (pressure: 0.1 MPa, spray distance: 10cm). The sprayed cleaning composition is collected in a storage tank, circulated, and reused. Next, a 1 L glass beaker was immersed in a rinsing tank containing 1 kg of water for rinsing, and then dried with nitrogen blow.
Using an optical microscope "Digital Microscope VHX-2000" (manufactured by Keyence Corporation), we visually observed the presence or absence of a resin mask remaining in the thin line part of the test piece after the cleaning test at 300 times magnification. Check for residue. Evaluation was performed based on the following evaluation criteria, and the results are shown in Table 1.
<Evaluation criteria>
A: No residue B: 1 to 10 residues C: 11 to 50 residues D: 51 or more residues

Here, FIG. 1A shows an example of an external photograph of a substrate to be cleaned before cleaning.
When the substrate to be cleaned (the test piece described above) shown in FIG. 1A was cleaned using the cleaning compositions of Comparative Examples 1 to 3, the appearance of the surface of each substrate after cleaning was observed as shown in FIG. 1C. As shown, resist residue was observed in both cases. On the other hand, when cleaning was performed using the cleaning compositions of Examples 1 to 4, when the appearance of each substrate surface after cleaning was observed, as shown in FIG. 1B, no resist residue was observed and no resin was observed. It was found that the mask could be removed efficiently.

As shown in Table 1, the cleaning compositions of Examples 1 to 4 were more effective at resin masks than Comparative Example 1 which did not contain Component A, Comparative Example 2 which did not contain Component B, and Comparative Example 3 which did not contain Component C. It was found that the removability was excellent.
For reference, we also have a thin line circuit pattern (thin line part) formed by copper plating on the surface of a glass epoxy multilayer board, and a resin mask that is a cured negative dry film resist between the formed thin line circuit pattern. When a test piece with a line width of 40 μm and a plating thickness of the fine line portion of 35 μm was cleaned using the cleaning compositions of Example 4 and Comparative Example 3, the appearance of each substrate surface after cleaning was When observed, no resist residue was observed in any case, and the resin mask was removed efficiently. From this, the cleaning composition of the present disclosure has a hardened resin mask on the surface of a substrate having metal wiring with a line width of 5 μm or more and 35 μm or less in the thin line portion and a thickness of 40 μm or more and 80 μm or less at the thickest portion. It can be said that it is useful as a cleaning agent for peeling a resin mask from a substrate.

According to the present disclosure, a cleaning method with excellent resin mask removability can be provided. By using the cleaning method of the present disclosure, it is possible to improve the performance and reliability of manufactured electronic components, and the productivity of semiconductor devices can be improved.

Claims (9)

A step of peeling off the resin mask from the object to be cleaned to which the resin mask is attached using a cleaning composition,
The cleaning composition is a cleaning composition containing quaternary ammonium hydroxide (component A), amino alcohol (component B), aromatic alcohol (component C), and water (component D),
The mass ratio D/C of component D and component C in the cleaning composition is less than 10,
The object to be cleaned to which the resin mask is attached is a substrate having a hardened resin mask on the surface of the substrate, which has metal wiring having a line width of 5 μm or more and 35 μm or less at the thin line portion and a thickness of 40 μm or more and 80 μm or less at the thickest portion. Yes, there is a cleaning method. The cleaning method according to claim 1, wherein the content of component C in the cleaning composition is 5% by mass or more and 15% by mass or less. The cleaning method according to claim 1 or 2, wherein the content of component D in the cleaning composition is 45% by mass or more and 80% by mass or less. The cleaning method according to any one of claims 1 to 3, wherein the content of component A in the cleaning composition is 2% by mass or more and 5% by mass or less. The cleaning method according to any one of claims 1 to 4, wherein the content of component B in the cleaning composition is 9% by mass or more and 15% by mass or less. 6. The cleaning method according to claim 1, wherein the substrate having metal wiring is a glass epoxy multilayer substrate having metal foil on the surface. The cleaning method according to any one of claims 1 to 6, wherein component B is a compound represented by the following formula (II).
In the above formula (II), R ⁵ represents a hydrogen atom, a methyl group, an ethyl group, or an aminoethyl group, R ⁶ represents a hydrogen atom, a hydroxyethyl group, a hydroxypropyl group, a methyl group, or an ethyl group, and R ⁷ represents a hydroxyethyl group or a hydroxypropyl group. The cleaning method according to any one of claims 1 to 7, wherein the mass ratio D/C of component D and component C in the cleaning composition is 5 or more and less than 10. A method for manufacturing an electronic component, comprising the step of cleaning an electronic circuit board having a resin mask using the cleaning method according to any one of claims 1 to 8.