JPH06151299A - Removing method for resist film image in forming process for various kinds of mask, and adhesive or adhesive sheet used therefor - Google Patents

Abstract

PURPOSE:To provide a method of removing a disused image of resist film on a mask forming metal material and curing-type pressure-sensitive adhesive or adhesive sheet or tape used therefor in an image forming process in the manufacture of various masks such as a thin film circuit evaporation mask or the like. CONSTITUTION:Curing-type pressure-sensitive adhesive or an adhesive sheet is pasted on the upside of an image of resist film provided onto a mask forming metal material in an image forming process in the manufacture of various masks, and the adhesive sheet and the resist material are separated off together after adhesive is hardened, whereby the resist film image on a metal material can be removed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention removes an unnecessary resist image on a metal material for forming a mask in a process of forming an image in manufacturing various masks such as a vapor deposition mask for a thin film circuit. And a curable pressure-sensitive adhesive used therefor, or an adhesive sheet such as a sheet or tape thereof.

[0002]

2. Description of the Related Art Various masks, such as vapor deposition masks for thin-film circuits, are made of metal materials such as stainless steel and molybdenum, and water soluble such as ammonium dichromate and polyvinyl alcohol, casein, cyclized rubber and gelatin. A resist material such as a mixture with a functional resin is applied, and a predetermined resist film image is formed on the metal material by a normal photo process. It is manufactured by using this as a mask to etch the metal surface of the opening. Next, the unnecessary resist film image is generally removed from the mask forming metal material with a solvent such as a resist stripping solution.

[0003]

However, when a solvent is used to remove the resist film image, the metal surface may be contaminated by the impurities contained in the resist or the solvent, and the reliability may be lowered. Further, there is a problem that the working environment is damaged. Therefore, the present invention provides a simple and reliable method for removing an unnecessary resist film image on a metal material for mask formation by a completely different novel method, and a specific curable pressure-sensitive adhesive used for the method. The purpose is to provide agents or adhesive sheets.

[0004]

Means for Solving the Problems The inventors of the present invention, when removing unnecessary resist film images on various metal materials for mask formation, use a specific curable pressure-sensitive adhesive or an adhesive sheet using the same. It has been found that the use of a resist film enables the resist film image to be easily and reliably removed without causing a decrease in reliability and without causing a problem of damaging the working environment, and has completed the present invention.

That is, according to the present invention, in the process of forming various masks, a curable pressure-sensitive adhesive or adhesive sheets is attached to the upper surface of an image made of a resist material provided on a mask forming metal material, and the above-mentioned adhesion is performed. The present invention relates to a method for removing a resist film image in a process of forming various masks, which comprises removing the resist film image on the metal material by integrally separating the adhesive sheet and the resist material after the agent is cured.

The present invention also relates to a specific curable pressure-sensitive adhesive, which will be described later, as an adhesive or an adhesive sheet used in the above method, and an adhesive sheet having the same on a base material.

[0007]

According to the method of removing a resist film image in the image forming process of various masks of the present invention, first, the affinity for the resist material is formed on the mask forming metal material on which the image of the resist material exists. Adhere adhesive sheets using a good curable pressure-sensitive adhesive. At this time, the resist material and the adhesive are favorably adhered and integrated. However, in order to promote the adhesive integration by further partially penetrating the adhesive into the concave portion of the resist film image, It is preferable to heat and / or pressurize.

The curable pressure-sensitive adhesive used here is an adhesive which has a good affinity with the resist material on the mask-forming metal material and is cured by heating or light irradiation to become integrated with the resist material. The present invention also provides an adhesive that serves this purpose.

As the pressure-sensitive adhesive polymer in such a curable pressure-sensitive adhesive, any of various known polymers applied to general pressure-sensitive adhesives can be used. Particularly preferred polymers are alkyl acrylates. An acrylic polymer containing an ester and / or an alkyl methacrylate as a main monomer can be used.

The acrylic polymer is a main monomer described above, that is, an ester of acrylic acid or methacrylic acid with an alcohol having a carbon number of usually 12 or less, a monomer having a carboxyl group or a hydroxyl group if necessary, and other modifications. It can be obtained by polymerizing these using a monomer for use by a conventional method such as solution polymerization, emulsion polymerization, suspension polymerization and bulk polymerization.

Examples of the carboxyl group-containing monomer include acrylic acid, methacrylic acid, maleic acid,
Itaconic acid or the like is used, and as the hydroxyl group-containing monomer, for example, hydroxyethyl acrylate, hydroxypropyl acrylate or the like is used. The amount of these monomers used is preferably 20% by weight or less based on the total amount of all the monomers.

As the above-mentioned other modifying monomers, vinyl acetate, vinyl propionate, styrene, acrylonitrile, acrylamide, couglycidyl methacrylate and the like are used. The amount of these modifying monomers used is preferably 50% by weight or less in the total amount with the main monomer.

The acrylic polymer composed of such monomers has a weight average molecular weight of usually 30.
It is preferably from 10,000 to 2,000,000. If the molecular weight is too low, the viscosity will be low when the non-volatile compound described below is blended therein, and problems such as flowing during storage are likely to occur, and if it is too high, handling problems are likely to occur. Further, this acrylic polymer has a glass transition point of 2 in consideration of workability at the time of removing the resist film image.
It is preferably 50 ° K or less. If it is higher than this, it tends to be too hard after curing and the peeling tends to be heavy. However, the use of the acrylic polymer having such a high glass transition point is not intended to be excluded, and it goes without saying that it can be used depending on the case.

The curable pressure-sensitive adhesive used in the present invention is a non-volatile compound having good affinity with the pressure-sensitive adhesive polymer for resist materials and having at least one unsaturated double bond in the molecule. Is included.

Here, having a good affinity with the resist material means that the phenomenon of dissolving, swelling or destroying the resist material is remarkable, and also includes the phenomenon of migration or diffusion into the resist material. Be done. As a guide for this,
The resist material in which the solvent is sufficiently dried is immersed in this nonvolatile compound, and for example, the resist material is dissolved, swelled or destroyed when stored at 130 ° C. for 24 hours. Further, that the compound is non-volatile means that it is not easily volatilized in the step of coating and drying the adhesive.

Such a non-volatile compound has a function such that after the adhesive sheets are adhered on the mask-forming metal material on which an image is present, the resist material and the adhesive are integrated by the action of this compound and then cured. Have. Therefore, this non-volatile compound has one or more unsaturated double bonds that can be cured by heat or light in the molecule, and has good affinity with the resist material (which can be defined as above). It is also required that the compatibility with the pressure-sensitive adhesive polymer is good and that the polymer does not flow out during storage.

Examples of such non-volatile compounds include phenoxy polyethylene glycol (meth) acrylate, ε-caprolactone (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate and trimethylolpropane tri. (Meth) acrylate, dipentaerythritol hexa (meth) acrylate, urethane (meth) acrylate, epoxy (meth) acrylate, oligoester (meth) acrylate, and the like. Among these, the type of pressure-sensitive adhesive polymer used One or two or more of them can be appropriately selected and used depending on the target resist material.

The amount of the non-volatile compound used is usually 5 to 20 with respect to 100 parts by weight of the pressure-sensitive adhesive polymer.
The amount is 0 parts by weight, preferably 10 to 100 parts by weight. If the amount used is too small, the peeling effect of the resist material may not be sufficient, and if it is too large, the adhesive may flow out during storage, which is not preferable.

In the above-mentioned curable pressure-sensitive adhesive used in the present invention, the pressure-sensitive adhesive polymer is cross-linked to enhance cohesive force from the viewpoint of workability when it is attached to the mask forming metal material. Is preferred. For example, an acrylic polymer obtained by copolymerizing a carboxyl group- or hydroxyl group-containing monomer as a pressure-sensitive adhesive polymer is used, and a polyfunctional compound that reacts with the functional group of the polymer, such as polyisocyanate, polyepoxy, various metal salts, By containing a chelate compound or the like in the adhesive, the above reaction can be promoted in the step of forming a sheet or the like to crosslink the polymer.

The amount of the polyfunctional compound used is usually 20 parts by weight or less based on 100 parts by weight of the pressure-sensitive adhesive polymer. Within this range, the higher the molecular weight of the polymer, the lower the molecular weight of the polymer. , May be selected as appropriate.
If the amount of the polyfunctional compound used is too large, the adhesive strength will decrease, which is not preferable.

Further, the curable pressure-sensitive adhesive may contain a filler such as finely divided silica for the same purpose as the use of the above-mentioned polyfunctional compound. Further, various additives such as a tackifier, a colorant and an anti-aging agent may be contained if necessary. The amount of these used may be in the usual range.

To the curable pressure-sensitive adhesive that can contain such various components, a polymerization initiator can be added depending on the curing means. For example, in the case of heat curing, benzoyl peroxide, a thermal polymerization initiator such as azobisisobutyronitrile that generates radicals by heating is used, and in the case of photocuring such as ultraviolet light, benzoin, benzoin ethyl ether, A photopolymerization initiator that generates radicals by light irradiation such as dibenzyl is used. These polymerization initiators are usually used in the range of 0.1 to 10 parts by weight with respect to 100 parts by weight of the pressure-sensitive adhesive polymer.

The curable pressure-sensitive adhesive of the present invention thus constituted has an initial elastic modulus, that is, an elastic modulus before curing of usually about 0.5 to 50 g / mm ² , and an elastic modulus after curing. It is desirable that the rate is adjusted to about 3 to 400 g / mm ² . This is because when the elastic modulus is adjusted to such a range, favorable results can be obtained for both the pressure-sensitive adhesive property before curing and the resist releasability after curing. To adjust the elastic modulus, the kind of the pressure-sensitive adhesive polymer, the amount of the non-volatile compound added to the polymer, the amount of other compounding components, the degree of crosslinking by the polyfunctional compound, the curing conditions, and the like are appropriately selected. Can be done by.

The above-mentioned elastic modulus was determined by conducting a tensile test with an adhesive having a cross-sectional area of 5 mm ² under a temperature of 23 ± 2 ° C. with a marked line distance of 10 mm and a tensile speed of 50 mm / min. It means a value measured by a method of obtaining a curve and obtaining it from an initial slope.

When used, such a curable pressure-sensitive adhesive can be formed into a sheet or tape by itself, but it is usually dried on a film substrate. To be about 10 to 180 μm, and the adhesive sheet for image removal of the present invention can be obtained. Such a film substrate is made of, for example, polyethylene, polypropylene, polyethylene terephthalate, polyurethane, polyvinyl chloride, saponified ethylene / vinyl acetate copolymer, etc., and usually has a thickness of about 12
A resin film having a thickness of up to 100 μm is used, and in particular, when the adhesive is cured by irradiation with light, a film that transmits light such as ultraviolet rays is selected and used.

In the method of removing a resist film image in the mask image forming step of the present invention, an adhesive sheet using the curable pressure-sensitive adhesive having the above-mentioned constitution is stuck on the mask forming metal material on which the image exists. After the resist material and this adhesive are integrated, a predetermined curing treatment is performed by heating or light irradiation. At this time, when thermal effects are taken into consideration, curing treatment by light irradiation is particularly suitable, and the irradiation amount is usually 300 to 3000 mj / cm ^{2 with} ultraviolet rays.
It is better to set the range.

By this curing treatment, the adhesive is cured in a state of being integrated with the resist material, and the elastic modulus thereof is remarkably increased as described above, and accordingly, the resist film image and the mask forming metal material are formed. The adhesive strength is greatly reduced. As a result, by peeling the adhesive sheets after this curing,
The resist film image on the mask forming metal material can be easily and completely peeled and removed by being integrated with the adhesive sheets.

[0028]

As described above, according to the present invention, it is possible to easily and surely remove a resist film image without problems such as a decrease in reliability and a deterioration of working environment as in the conventional method using a solvent. You can

[0029]

EXAMPLES The present invention will be described below based on examples. In addition, "parts" means "parts by weight".

Example 1 80 parts of n-butyl acrylate, 15 ethyl acrylate
Part of the monomer mixture consisting of 5 parts of acrylic acid and 150 parts of ethyl acetate and 0.1 part of azobisisobutyronitrile were subjected to solution polymerization at 60 ° C. for 12 hours under a nitrogen stream to give a weight average molecular weight of 56. The glass transition point is 231 °
An acrylic polymer solution of K was obtained.

To 250 parts of this acrylic polymer solution,
100 parts of urethane acrylate as a non-volatile compound,
3 parts of diphenylmethane diisocyanate as a polyfunctional compound and 3 parts of benzyl methyl ketal as a polymerization initiator were uniformly mixed to obtain a curable pressure-sensitive adhesive solution.

Next, the curable pressure-sensitive adhesive solution was added to
It was coated on a polyester film having a thickness of 50 μm so that the thickness after drying was 50 μm, and dried at 150 ° C. for 10 minutes to prepare an adhesive tape for removing a resist film image of the present invention.

Comparative Example 1 250 parts of the acrylic polymer solution of Example 1 was uniformly mixed with 3 parts of diphenylmethane diisocyanate to prepare a pressure-sensitive adhesive solution, and then an adhesive tape was prepared in the same manner as in Example 1. did.

Example 2 A monomer mixture consisting of 60 parts of 2-ethylhexyl acrylate, 30 parts of butyl acrylate, 5 parts of vinyl acetate and 5 parts of acrylic acid was polymerized in the same manner as in Example 1 to give a weight average molecular weight of 62. By the way, an acrylic polymer solution having a glass transition point of 207 ° K was obtained.

To 250 parts of this acrylic polymer solution,
Oligoester acrylate 10 as non-volatile compound
0 part, 3 parts of tolylene diisocyanate as a polyfunctional compound, and 5 parts of benzyl methyl ketal as a polymerization initiator were uniformly mixed to obtain a curable pressure-sensitive adhesive solution, which was adhered in the same manner as in Example 1. Got the tape.

[Measurement of Elastic Modulus] The initial elastic modulus of the pressure-sensitive adhesive of the adhesive tape obtained in each example and ultraviolet rays were irradiated at a dose of 1000 mj / cm ² using a high pressure mercury lamp to cure the adhesive tape. As a result of measuring the elastic modulus after the test, it was as shown in Table 1 below.

[0037]

[Table 1]

(Evaluation of Removal Performance of Resist Film Image) The adhesive tape obtained in each of the examples was used as a resist material composed of ammonium dichromate and polyvinyl alcohol on the surface of stainless steel for forming a vapor deposition mask for thin film circuits. Was applied, exposed and developed on the resist film image by heating and pressure bonding with a heating roll at 100 ° C., and then ultraviolet rays were irradiated at a dose of 1000 mj / cm ² using a high pressure mercury lamp,
The curable pressure sensitive adhesive was cured.

After this curing, when the adhesive tape was peeled off, all the above resist film images were peeled off together with the adhesive tape. The surface of the obtained vapor deposition mask for thin film circuits was observed with a fluorescence microscope, but no resist film image was observed.

The adhesive tapes obtained in each of the comparative examples were evaluated for their resist film image removal performance in the same manner as described above. Only the adhesive tape was peeled off, and the resist film image was almost entirely on the surface of the vapor deposition mask for thin film circuits. It was left.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hideaki Shimodan 1-2-1, Shimohozumi, Ibaraki City, Osaka Prefecture Nitto Denko Corporation

Claims (7)

[Claims] 1. In various mask forming steps, a curable pressure-sensitive adhesive or an adhesive sheet is attached to the upper surface of an image made of a resist material provided on a mask forming metal material, and the adhesive is cured. After that, the adhesive film and the resist material are integrally peeled off to remove the resist film image on the metal material, and the resist film image removing method in the step of forming various masks. 2. The method for removing a resist film image in the step of forming various masks according to claim 1, wherein the mask is a vapor deposition mask for thin film circuits. 3. The method for removing a resist film image according to claim 1 or 2, wherein a curable pressure-sensitive adhesive or adhesive sheets are attached, and then the adhesive is pressed and / or heated to form a resist film image. A method for removing a resist film image, which comprises partially infiltrating into the concave portion of and then curing. 4. A curable pressure-sensitive adhesive or adhesive sheets for use in a method of removing a resist film image in the step of forming various masks according to claim 1, wherein the curable pressure-sensitive adhesive is pressure-sensitive. A curable pressure-sensitive adhesive for image removal, characterized in that the adhesive polymer contains a nonvolatile compound having a good affinity with a resist material and having one or more unsaturated double bonds in the molecule. Or adhesive sheets. 5. The curable pressure-sensitive adhesive or the adhesive sheet according to claim 4, wherein the pressure-sensitive adhesive polymer is an acrylic polymer having an alkyl (meth) acrylate as a main monomer. 6. The curable pressure-sensitive adhesive according to claim 4 or 5, wherein the curable pressure-sensitive adhesive further contains a polyfunctional compound for crosslinking the pressure-sensitive adhesive polymer. Adhesive sheets. 7. The curable pressure-sensitive adhesive or the adhesive sheet according to claim 4, wherein the curable pressure-sensitive adhesive further contains a polymerization initiator.