JP7410053B2 - Positive dry film resist and etching method - Google Patents

Description

The present invention relates to a positive dry film resist and an etching method.

Resists are used in the production of printed wiring boards, lead frames, metal masks, shadow masks, semiconductor packages, electrode members, electromagnetic shields, etc., and in metal processing such as metal etching and metal plating. For example, in the manufacture of metal masks, lead frames, shadow masks, printed circuit boards, etc., methods of etching the metal of various base materials are used. The resist used for this etching is a photosensitive resin composition that utilizes photocrosslinking by mixing a photocrosslinking reagent such as ammonium dichromate with a water-soluble polymer such as polyvinyl alcohol (PVA), gelatin, or casein. things have been used. However, this photosensitive resin composition has problems such as difficulty in disposing of chromium waste liquid, and is now mostly replaced by dry film resists using alkaline aqueous solution developable photosensitive resin compositions. .

Currently, negative-type photosensitive resists are used as dry film resists, and a composition containing an alkali-soluble resin, a photopolymerizable crosslinking agent, and a photopolymerization initiator is generally used. A dry film resist is thermocompression bonded to the base material, and the photosensitive resin layer is imagewise cured by exposure to ultraviolet rays through an image-formed photomask to make it slightly soluble, and then it is cured with an alkaline developer such as a 1% by mass aqueous sodium carbonate solution. A resist pattern is formed by dissolving the unexposed areas into a developer.

However, negative photosensitive resists have the problem of sensitivity change due to aging and the problem of resist component residues remaining on the surface of the substrate after development. Further, when removing the resist after metal etching, it is necessary to use a special removing liquid that is strongly alkaline or contains an organic amine.

On the other hand, positive photosensitive resists are not easily affected by oxygen in the air, which inhibits photopolymerization, and their sensitivity changes little over time.Furthermore, after metal etching, the entire surface of the resist is exposed to light using a developer, etc. The treatment has the advantage that the resist pattern can be easily dissolved and peeled off. In addition, compared to negative photosensitive resists, resists are less likely to swell in developing solutions, which is advantageous for fine patterns.

For positive photosensitive resists, liquid resists have been widely used in recent years, and the method of forming a resist layer on the substrate is to apply it directly to the substrate using spin coating, roll coating, etc. has been done. However, in liquid resist, there is a lot of liquid loss, and the coating process is time-consuming. Since positive photosensitive resists are expensive, liquid loss is undesirable. Furthermore, in the case of a liquid resist, it is difficult to form a resist layer on both sides simultaneously or to form a resist layer uniformly. Therefore, there is a strong demand for a method in which a positive photosensitive resist is used as a dry film resist, and the resist is laminated by thermocompression bonding.

On the other hand, positive photosensitive resists that have been widely used include materials containing quinonediazide-based materials and novolac resins as main components. When this positive photosensitive resist is coated on a support such as a polyethylene terephthalate film to form a positive dry film resist, the adhesive strength between the support film and the positive photosensitive resist layer is high, and it can be applied onto the substrate using the lamination method. There was a problem that the support film could not be peeled off in the step of peeling off the support film after thermocompression bonding (for example, Patent Document 1).

Furthermore, even if the positive photosensitive resist layer can be attached to the base material, the amount of side etching during the etching process is limited due to the lack of adhesion of novolak resin to the base material such as copper-clad laminates. There was a problem in that the line width became large and variations in line width occurred.

Further, since the novolak resin is hard, has a brittle film quality, and lacks flexibility, there is a problem in that it is difficult to stick to the substrate when it is thermocompressed onto the substrate by a lamination method. It is possible to laminate by supplying sufficient heat and pressure by raising the temperature of the laminator's hot roll or slowing down the conveyance speed, but if the temperature exceeds 130°C, the support This causes problems such as softening and expansion/contraction. In addition, since the positive photosensitive resist layer is difficult to soften sufficiently, a problem may occur in which air bubbles enter between the base material and the positive photosensitive resist layer.

In addition, the softening point of the positive photosensitive resist layer can be lowered by adding a plasticizer to the positive photosensitive resist layer or lowering the softening point of the novolak resin so that it can be bonded by thermocompression using the lamination method. Laminate properties may be imparted.
However, in this case, if the support film is coated with a coating liquid for a positive photosensitive resist layer, dried, wound up, and stored in a roll, the positive photosensitive resist layer will be formed even after long-term storage at room temperature. However, a problem called "blocking" occurs in which the film sticks to the support film on the opposite side.

To solve this problem, for example, in the case of a negative photosensitive resist, a measure is taken to attach a polyethylene film or a polypropylene film as a protective film to the photosensitive resist layer.
However, when using a polyethylene film or polypropylene film as a protective film in a positive dry film resist, it is difficult to attach the protective film at room temperature due to insufficient adhesion, and it is difficult to apply heat to the protective film. When affixing the polyethylene film or polypropylene film, wrinkles occurred on the polyethylene film or polypropylene film, which was a problem.

It is also possible to make the positive photosensitive resist layer hard so as not to cause blocking. However, since the positive photosensitive resist layer lacks flexibility in the first place, the above-mentioned problems are more likely to occur. Furthermore, since the positive photosensitive resist layer lacks flexibility and is brittle, cracks may occur if the positive dry film resist is bent. Further, there is a problem in forming a positive dry film resist into a roll. That is, normally, slitting is performed from a wide roll into a roll product of a desired width, but cracks occur in the brittle positive photosensitive resist layer and chips are likely to be generated from the edges.
In addition, normally, a roll of positive dry film resist is continuously thermocompressed onto a sheet of base material, but it is necessary to cut the positive dry film resist between each base material, and at that time, the positive dry film resist is The photosensitive resist layer is likely to crack and generate chips. Then, there are cases where the chips adhere to the base material and cause defects (for example, Patent Document 2).

A solution to these problems is to provide a release layer between the support film and the positive photosensitive resist layer (for example, Patent Documents 3 and 4).

Patent Document 3 discloses a method comprising, in this order, a peelable support layer (support film) having a release layer, a first layer of a photoresist layer, and a second layer of an attachable crosslinked or crosslinkable organic polymer. A multilayer dry film photoresist is disclosed. Further, Patent Document 4 discloses a resist film including a support film (support film), a dry film resist film for reinforcing the mechanical strength of the resist film, and a resist film used for pattern formation. ing. The peeling layer can facilitate peeling off the support film after thermocompression bonding. In addition, even if the positive dry film resist is bent, it should be cut or slit to prevent the positive photosensitive resist layer from cracking and to prevent the release layer and positive photosensitive resist layer from peeling off. It is necessary to increase the adhesion between the release layer and the positive photosensitive resist layer in order to prevent cracks from occurring. However, the stronger the adhesion between the release layer and the positive photosensitive resist layer, the more likely it is that only the support film is peeled off after thermocompression bonding, and the release layer tends to remain on the positive photosensitive resist layer. If the release layer remains on the positive photosensitive resist layer, gas generated from the exposed portion of the positive photosensitive resist layer during exposure will accumulate between the positive photosensitive resist layer and the release layer. As a result, a problem may occur in which defects occur in the image after development. In Patent Document 3, since the support film of the photoresist layer has a second layer that can be attached, peeling and peeling of the photoresist layer is suppressed. However, in order to form a fine pattern, it is preferable that there is no second layer.

In Patent Document 4, a dry film resist film for reinforcing mechanical strength is removed by chemical treatment, and then a pattern is formed with the resist film, so the problem of image defects due to gas does not occur, but the problem of image defects due to gas does not occur. It is necessary to increase the number of processes. Therefore, it is required to be able to easily peel off the support film and the release layer from the interface between the positive photosensitive resist layer and the release layer after thermocompression bonding the positive dry film resist to the base material.

Additionally, when a release layer is provided between the support film and the positive photosensitive resist layer, pinhole defects occur in the positive photosensitive resist layer formed on the release layer that contains air bubbles and foreign matter. was there.

JP2006-267660A Japanese Patent Application Publication No. 2002-341525 Japanese Patent Application Publication No. 59-083153 Patent No. 3514415

An object of the present invention is to provide a positive dry film resist having at least one of the following characteristics, and an etching method using the positive dry film resist.

<A> After thermocompression bonding the positive dry film resist to the base material, the support film and release layer can be easily peeled off from the interface between the positive photosensitive resist layer and the release layer.

<B> Peeling or cracking is less likely to occur when the positive dry film resist is cut or slit or when the positive dry film resist is bent.

<C> When a positive dry film resist is attached to a base material using a laminator, air bubbles are difficult to enter between the positive photosensitive resist layer and the base material, and the resist can be attached well.

<D> The amount of side etching is small, the variation in line width is small, and it is possible to form fine patterns.

<E> Pinhole defects are less likely to occur.

<F> Blocking is unlikely to occur between the support film and the positive photosensitive resist layer.

The above problem is solved by the following means.

<1>
At least (a) a support film, (b) a release layer, and (c) a positive photosensitive resist layer are laminated in this order, (b) the release layer contains polyvinyl alcohol, and (c) a positive photosensitive resist layer is formed. A positive dry film resist characterized in that the type photosensitive resist layer contains a novolac resin and a quinone diazide sulfonic acid ester as main components.

<2>
(b) The positive dry film resist according to <1>, wherein the content of polyvinyl alcohol is 80% by mass or more based on the total nonvolatile content of the release layer.

<3>
(c) The positive dry film resist according to <1> or <2>, wherein the positive photosensitive resist layer contains polypropylene glycol glyceryl ether.

<4>
The positive dry dry according to any one of <1> to <3>, wherein the novolak resin includes an o-cresol novolak resin having a mass average molecular weight (Mw) of 16,000 to 75,000, and the quinonediazide sulfonic acid ester includes a naphthoquinonediazide sulfonic acid ester. film resist.

<5>
The positive dry film resist according to any one of <1> to <4>, wherein the polyvinyl alcohol contains polyvinyl alcohol with a saponification degree of 82 mol% or more.

<6>
(a) Corona discharge treatment is applied to the (b) release layer side of the support film, (b) the release layer has a thickness of 1 to 4 μm, and (c) the positive photosensitive resist layer has a thickness of The positive dry film resist according to any one of <1> to <5>, having a diameter of 3 to 8 μm.

<7>
At least (a) a support film, (b) a release layer, (c) a positive photosensitive resist layer, and (d) a protective film are laminated in this order, and (d) the protective film is made of a self-adhesive resin film. The positive dry film resist according to any one of <1> to <6>.

<8>
(c) a positive photosensitive resist layer of the positive dry film resist according to any one of <1> to <6> is attached to at least one side of the base material by a lamination method, and (a) a support film and (b) ) simultaneously removing the release layer, then exposing the desired pattern to light, then (c) developing the positive photosensitive resist layer with a developer to form a resist pattern, then etching the substrate; Next, an etching method involves stripping the resist using a stripping solution.

<9>
After peeling off the protective film (d) of the positive dry film resist described in <7>, attaching (c) the positive photosensitive resist layer of the positive dry film resist to at least one side of the substrate by a lamination method, (a) simultaneously removing the support film and (b) the release layer, then exposing the desired pattern to light, and then developing (c) the positive photosensitive resist layer with a developer to form a resist pattern; An etching method in which the base material is then etched, and then the resist is removed using a remover.

In one embodiment of the positive dry film resist of the present invention, as shown in FIG. 1, at least (a) a support film, (b) a release layer, and (c) a positive photosensitive resist layer are laminated in this order. Become. According to the positive dry film resist of the present invention, it is possible to solve the above problems.

(c) The positive photosensitive resist layer contains a novolac resin that is hard and has low flexibility, but the (b) release layer provides adhesion between the (b) release layer and (c) the positive photosensitive resist layer. is high, and even if the positive dry film resist is bent or cut or slit, cracks are less likely to occur.
In addition, the adhesion between (a) the support film and (b) the release layer is strong, so even if the positive dry film resist is bent, there will be no peeling between the (a) support film and (b) the release layer, and Peeling between (b) the release layer and (c) the positive photosensitive resist layer is less likely to occur.
(b) When the content of polyvinyl alcohol is 80% by mass or more with respect to the total nonvolatile content of the release layer, any of the above adhesion forces becomes stronger.

(c) Among the components in the positive photosensitive resist layer, the main components, novolac resin and quinonediazide sulfonic acid ester, exhibit photosensitivity.

(c) When the positive photosensitive resist layer contains polypropylene glycol glyceryl ether, (c) the positive photosensitive resist layer can be softened and the lamination properties can be improved. By containing polypropylene glycol glyceryl ether, (c) positive photosensitive resist layer can be improved without impairing the photosensitive characteristics and development characteristics such as sensitivity, alkali developability, resist shape, etc. The resist layer can be softened, and (c) air bubbles can be prevented from entering between the positive photosensitive resist layer and the base material, allowing for good attachment.

In addition, when the novolak resin contained in (c) the positive photosensitive resist layer contains an o-cresol novolak resin having a mass average molecular weight (Mw) of 16,000 to 75,000, (b) a release layer containing polyvinyl alcohol and (c) The adhesion between the positive photosensitive resist layers is high, and the (a) support film and (b) release layer are also tightly bonded, so even if the positive dry film resist is cut or slit, it will not break. is difficult to occur.
Furthermore, even when the positive dry film resist is bent, the (b) release layer and (c) positive photosensitive resist layer are unlikely to peel off. Furthermore, since the novolac resin contains an o-cresol novolac resin having a mass average molecular weight (Mw) of 16,000 to 75,000, (c) excellent adhesion between the positive photosensitive resist layer and the base material is achieved, and the line width after etching is improved. The dispersion becomes smaller.

After thermocompression bonding the positive dry film resist to the base material, (a) it is necessary to peel off the support film, but (b) because the peeling layer contains polyvinyl alcohol with a saponification degree of 82 mol% or more, (a) The support film and (b) the release layer can be easily peeled off from the interface between the (b) release layer and (c) the positive photosensitive resist layer.

Further, by using an o-cresol novolac resin having a mass average molecular weight (Mw) of 16,000 to 75,000 as the novolac resin, it has excellent adhesion to the base material and the variation in line width after etching is reduced.

In addition, corona discharge treatment is applied to the (b) release layer side of the (a) support film, which increases the adhesion to the (b) release layer and (c) allows the positive photosensitive resist layer to (a) The support film and (b) the release layer can be easily peeled off at the same time.
In addition, (b) when the thickness of the release layer is 1 to 4 μm, leveling progresses during coating, resulting in the effect of reducing pinhole defects caused by air bubbles and the like. Note that even if the thickness of (b) the release layer is as thin as 4 μm or less, if (a) the support film has been subjected to corona discharge treatment, after attaching the positive dry film resist to the base material, ( It is difficult to peel off from the interface between a) the support film and (b) the release layer, and it becomes easy to remove the support film (a) and the release layer (b) at the same time.

In addition, (c) the positive-type photosensitive resist layer is often hard and has low flexibility, but because it has a thickness of 3 to 8 μm, when cutting or slitting the positive-type dry film resist, it is necessary to Chips are less likely to be generated, and (a) the support film and (b) the release layer can be easily peeled off from the interface between the (b) release layer and (c) the positive photosensitive resist layer.

In another embodiment of the positive dry film resist of the present invention, as shown in FIG. 2, at least (a) a support film, (b) a release layer, (c) a positive photosensitive resist layer, and (d) a protective film. are stacked in this order.
(d) Since the protective film is a self-adhesive resin film, there is no need to (c) apply heat to the positive photosensitive resist layer and (d) apply the protective film, and it is also possible to use a positive dry film resist. Even when cut or slit, cracks and chips are less likely to occur, and blocking is less likely to occur.

FIG. 1 is a schematic cross-sectional view showing one embodiment of a positive dry film resist of the present invention. FIG. 3 is a schematic cross-sectional view showing another embodiment of the positive dry film resist of the present invention.

<Positive dry film resist>
In one embodiment of the positive dry film resist of the present invention, at least (a) a support film, (b) a release layer, and (c) a positive photosensitive resist layer are laminated in this order. In another embodiment, at least (a) a support film, (b) a release layer, (c) a positive photosensitive resist layer, and (d) a protective film are laminated in this order.
Further, (b) the release layer contains polyvinyl alcohol, and (c) the positive photosensitive resist layer contains a novolac resin and a quinone diazide sulfonic acid ester as main components.

<(a) Support film>
(a) As the support film, any film may be used as long as it can form a (b) release layer and can be peeled off after the positive dry film resist is attached to the base material by a lamination method. . It may be a transparent film that transmits light, or a white film or a colored film that blocks light.
For example, polyolefins such as polypropylene and polyethylene; polyimides; films of polyesters such as polyethylene naphthalate, polyethylene terephthalate, and flame-retardant polyethylene terephthalate; films of polycarbonate, polyphenylene sulfide, polyetherimide, modified polyphenylene ether, polyurethane, and the like can be used. Among these, the use of polyethylene terephthalate film is particularly advantageous in terms of lamination suitability, peelability, and smoothness, and it is also inexpensive, does not become brittle, has excellent solvent resistance, and has high tensile strength. It is very easy to use.

(a) The thickness of the support film is preferably 1 to 100 μm, more preferably 12 to 50 μm.

In the present invention, it is preferable that the (b) release layer side of the (a) support film is subjected to corona discharge treatment before forming the (b) release layer. In the corona discharge treatment, corona discharge is irradiated from the electrode toward the surface of the support film. (a) By subjecting the surface of the support film to corona discharge treatment, the surface tension can be lowered, (b) the adhesion with the release layer can be increased, and (c) the positive photosensitive resist layer (a ) It becomes easier to peel off the support film and (b) the release layer at the same time. A preferable amount of corona discharge is 10 to 200 W·min/m ² .

<(b) Peeling layer>
(b) The release layer contains polyvinyl alcohol.
By coating an aqueous polyvinyl alcohol solution, which is a coating liquid for a release layer, on the (a) support film, the release layer (b) can be formed.
(b) If corona discharge treatment is applied to the (b) release layer side of the support film (b) before forming the release layer, apply a polyvinyl alcohol aqueous solution to the (a) corona discharge of the support film. (b) A release layer can be formed by coating on the treated surface (corona discharge treated surface) and drying.

In the present invention, the (b) release layer has a characteristic that allows the (c) positive photosensitive resist layer to be evenly and uniformly formed on the (b) release layer. Furthermore, it has excellent adhesion between (a) the support film and (b) the release layer, and also has excellent adhesion between the (b) release layer and (c) the positive photosensitive resist layer.

(b) In the release layer, the content of polyvinyl alcohol is preferably 80 to 100% by mass, more preferably 90 to 100% by mass, based on the total nonvolatile content of the release layer (b), More preferably, it is 95 to 100% by mass.
When the content is less than 80% by mass, the adhesion between (b) the release layer and (b) the positive photosensitive resist layer increases, so that the (b) release layer and (a) the support film are bonded together. It may become difficult to peel off, and (a) when the support film is peeled off, (b) the release layer may remain on (c) the positive photosensitive resist, or (c) the entire positive photosensitive resist layer may be removed. There is a risk of partial peeling.
In addition, the above-mentioned "total non-volatile content" refers to (a) when the coating liquid for a release layer is coated on (a) a support film and dried sufficiently to form (b) a release layer; Refers to the mass of the entire layer.

Note that when the content of polyvinyl alcohol is less than 100% by mass, the remaining components include low molecular compounds such as plasticizers, high molecular compounds, and the like. Examples of these compounds include polyethylene glycol, polypropylene glycol, poly(meth)acrylic acid, poly(meth)acrylic ester, carboxymethylcellulose (CMC), glue, casein, sodium alginate, vinyl acetate resin, polyvinylpyrrolidone, and Examples include water-soluble resins such as acryloylmorpholine.

(b) The polyvinyl alcohol used in the release layer preferably contains polyvinyl alcohol with a saponification degree of 82 mol% or more, particularly preferably polyvinyl alcohol with a saponification degree of 82 mol% or more.
The polyvinyl alcohol has a high adhesion between (a) the support film and (b) the release layer, and has a high adhesion between the (b) release layer and (c) the positive photosensitive resist layer. Even if the (c) positive photosensitive resist layer is bent, peeling of the (c) positive photosensitive resist layer is suppressed, and when the (a) support film and (b) release layer are peeled off from the (c) positive photosensitive resist layer. (c) Polyvinyl alcohol, which is less likely to cause cohesive failure of the positive photosensitive resist layer, is preferred.

The degree of saponification of the polyvinyl alcohol is more preferably 82 to 99.5 mol%, and even more preferably 83 to 98 mol%. The polyvinyl alcohol used may be unmodified, or may be partially modified with modified groups to impart functionality such as water resistance, solvent resistance, heat resistance, barrier properties, and flexibility. Moreover, a synthetic product or a commercially available product may be used.

Commercially available products include, but are not limited to, Kuraray Poval (registered trademark) 3-98, 4-98 HV, 5-98, 11-98, 28-98, 60-98, (and above) manufactured by Kuraray Co., Ltd. , Saponification degree = 98-99 mol%), 3-88, 5-88, 9-88, 22-88, 30-88, 44-88, 95-88 (Saponification degree = 86-89 mol%), 29 -99, 25-100 (Saponification degree = 99 mol% or more); JC-25, JC-33 (Saponification degree = 99 mol% or more), JF-03, JF- manufactured by Japan Vinyl Acetate Poval Co., Ltd. 04, JF-05 (Saponification degree = 98 to 99 mol%), JP-03, JP-04 (Saponification degree = 86 to 90 mol%), JP-05 (Saponification degree = 87 to 89 mol%), JP -45 (saponification degree = 86.5 to 89.5 mol%), JL-18E (saponification degree = 83 to 86 mol%); Gosenex (registered trademark) series Z-100, Z-200, Z manufactured by Mitsubishi Chemical Corporation -205 (above, saponification degree = 98 mol% or more), Z-300, Z-410 (above, saponification degree = 97.5 to 99 mol%), Z-210 (saponification degree = 95 to 97 mol%), Z-220 , Z-320 (saponification degree = 90.5 to 94 mol%), etc.

(b) In the release layer, the content of polyvinyl alcohol with a saponification degree of 82 mol% or more is preferably 80 to 100% by mass, and 90 to 100% by mass, based on the total nonvolatile content of the release layer (b). The content is more preferably 95 to 100% by mass.
If the content is less than 80% by mass, the adhesion between the (b) release layer and (c) positive photosensitive resist layer will become too high, causing the (b) release layer and (a) support film to become separated. It may become difficult to peel off the film at the same time as (a) when the support film is peeled off, (b) the release layer remains on (c) the positive-working photosensitive resist, or (c) the positive-working photosensitive resist Parts of the resist layer may peel off.
Note that when the content is less than 100% by mass, the remaining components are not particularly limited, but include the above-mentioned low-molecular compounds such as plasticizers, high-molecular compounds, and the like. Further, polyvinyl alcohol having a saponification degree of less than 82 mol% may be mentioned.

(b) The thickness of the release layer is preferably 1 to 20 μm, more preferably 1 to 10 μm, even more preferably 1 to 4 μm, and particularly preferably 1 to 2 μm. If it is thinner than 1 μm, problems such as thickness unevenness and pinholes may easily occur when a film is formed. If it is thicker than 20 μm, the coating liquid for the release layer (b) is water-based and therefore difficult to dry, and the drying process after coating tends to be prolonged.
Furthermore, in order to solve the problem of (b) bubbles remaining in the coating liquid for the release layer and resulting pinhole defects, it is preferable that the thickness of the release layer (b) is 4 μm or less. (b) The thickness of the release layer is the thickness after drying.

<(c) Positive photosensitive resist layer>
(c) The positive photosensitive resist layer contains a novolac resin and a quinone diazide sulfonic acid ester as main components. "Contained as a main component" means that the total content of the novolac resin and quinonediazide sulfonic acid ester is 60% by mass or more based on the total nonvolatile content of the positive photosensitive resist layer (c). The content is more preferably 70% by mass or more, even more preferably 75% by mass or more, and the upper limit is 100% by mass.
The above-mentioned "total non-volatile content" refers to the case where the coating liquid for a positive photosensitive resist layer is applied onto (b) the release layer and sufficiently dried to form (c) a positive photosensitive resist layer. (c) refers to the mass of the entire positive photosensitive resist layer.

The novolak resin is a resin obtained by condensing phenols or naphthols with aldehydes or ketones using an acid catalyst. In addition, "phenols" here also include "all products in which a phenolic hydroxyl group is bonded to an aromatic ring such as a benzene ring" such as cresols, xylenols, resorcinols, catechols, resorcinols, and pyrogallols. It includes.
Examples of the novolak resin include phenol novolak resin, cresol novolak resin, xylenol novolak resin, resorcinol novolak resin, and naphthol novolak resin.

There are no particular limitations on the phenols or naphthols that are the raw materials for the novolac resin, but examples include phenol, o-cresol, m-cresol, p-cresol, o-ethylphenol, m-ethylphenol, p-ethylphenol. , o-propylphenol, m-propylphenol, p-propylphenol, o-butylphenol, m-butylphenol, p-butylphenol, octylphenol, 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2, 6-xylenol, 3,4-xylenol, 3,5-xylenol, 2,3,5-trimethylphenol, 3,4,5-trimethylphenol, methoxyphenol, 2-methoxy-4-methylphenol, vinylphenol, allyl Phenol, benzylphenol, methoxycarbonylphenol, benzoyloxyphenol, chlorophenol, catechol, resorcinol, pyrogallol, bisphenol A, bisphenol F, β-naphthol, p-hydroxyphenyl-2-ethanol, p-hydroxyphenyl-3-propanol, Examples include p-hydroxyphenyl-4-butanol and hydroxyethylcresol. These phenols can be used alone or in combination of two or more.

The aldehydes or ketones used to obtain the novolak resin are not particularly limited, but include, for example, formaldehyde, acetaldehyde, propylaldehyde, butyraldehyde, isobutyraldehyde, furfural, benzaldehyde, hydroxybenzaldehyde, methoxybenzaldehyde, and hydroxyphenylacetaldehyde. , methoxyphenylacetaldehyde, crotonaldehyde, chloroacetaldehyde, chlorophenylacetaldehyde, acetone, glyceraldehyde, glyoxylic acid, methyl glyoxylate, phenyl glyoxylate, hydroxyphenyl glyoxylate, formylacetic acid, methyl formylacetate, and the like. These aldehydes or ketones can be used alone or in combination of two or more. Moreover, you may use these condensates.

The novolak resin preferably includes an o-cresol novolak resin, more preferably an o-cresol novolak resin having a mass average molecular weight (Mw) of 16,000 to 75,000.
Here, "o-cresol novolak resin" refers to o-cresol in an amount of 50 to 100 mol% based on the total amount of phenols or naphthols, which are raw materials for novolak resin, and which contains aldehydes or naphthols, which are raw materials for novolak resin. Refers to a resin containing 50 to 100 mol% of formaldehyde or a condensate of formaldehyde based on the total number of ketones.
o-cresol is more preferably contained in 60 to 100 mol%, even more preferably 70 to 100 mol%, even more preferably 80 to 100 mol%, even more preferably 90 to 100 mol%, and 96 to 100 mol%. % is particularly preferable. Further, it is more preferable that formaldehyde or a condensate of formaldehyde is contained in an amount of 60 to 100 mol%, even more preferably 70 to 100 mol%, even more preferably 80 to 100 mol%, and even more preferably 90 to 100 mol%. Preferably, it is particularly preferably contained in a range of 96 to 100 mol%.
When o-cresol is less than 100 mol%, the remaining components include, but are not particularly limited to, the aforementioned "phenols or naphthols".
When formaldehyde or a condensate of formaldehyde is less than 100 mol %, the remaining components include, but are not particularly limited to, the above-mentioned "aldehydes or ketones".

When the weight average molecular weight of the o-cresol novolac resin is 16,000 or more, acid resistance and adhesion to the base material can be increased, and the effect of reducing the amount of side etch during etching can be easily obtained. On the other hand, when the mass average molecular weight is 75,000 or less, the sensitivity is improved, the adhesion to the base material is extremely high, and the effect of reducing the amount of side etching in etching processing is likely to be obtained.
A more preferable weight average molecular weight is 22,000 to 51,000, and an even more preferable weight average molecular weight is 26,000 to 43,000. Here, the mass average molecular weight refers to the mass average molecular weight in terms of polystyrene measured by high performance liquid chromatography.

The content of the above-mentioned "o-cresol novolak resin having a mass average molecular weight (Mw) of 16,000 to 75,000" to the entire "(c) novolak resin contained in the positive photosensitive resist layer" is 60 to 100% by mass. It is preferably 70 to 100% by weight, more preferably 80 to 100% by weight, and particularly preferably 90 to 100% by weight.
By keeping it within the above range, the above-mentioned effects can be especially obtained.

If the above content is not 100% by mass, other novolak resins include the above-mentioned novolak resins, novolak resins obtained from the above-mentioned raw materials, and those having a mass average molecular weight (Mw) in the range of 16,000 to 75,000. Examples include o-cresol novolac resins.

(c) The quinonediazide sulfonic acid ester contained in the positive photosensitive resist layer includes, for example, o-naphthoquinonediazide sulfonic acid ester of 2,4-dihydroxybenzophenone, 2,3,4-trihydroxy Examples include o-naphthoquinonediazide sulfonic acid ester of benzophenone and o-naphthoquinonediazide sulfonic acid ester of 2,3,4,4'-tetrahydroxybenzophenone. Further, examples thereof include quinonediazide sulfonic acid ester of phenol resin, quinonediazide sulfonic acid ester of cumylphenol, and quinonediazide sulfonic acid ester of pyrogallol acetone resin.
In the present invention, it is preferable that the quinonediazide sulfonic acid ester includes a naphthoquinonediazide sulfonic acid ester.

In the present invention, the amount of quinonediazide sulfonic acid ester blended is preferably 10 to 50 parts by weight, more preferably 15 to 40 parts by weight, based on 100 parts by weight of the novolak resin. By using this amount, the acid resistance and adhesion to the base material are excellent, and it is suitable for etching various materials such as metals and metal oxide films.

In the present invention, (c) the positive photosensitive resist layer contains the above-mentioned "novolak resin containing an o-cresol novolak resin having a mass average molecular weight (Mw) of 16,000 to 75,000," and the quinonediazide sulfonic acid ester is naphthyl. Particularly preferred is a quinonediazide sulfonic acid ester.

In the present invention, the positive photosensitive resist layer (c) preferably contains polypropylene glycol glyceryl ether. Polypropylene glycol glyceryl ether is a compound represented by general formula (i), and preferably m+n+o=3 to 50.
The average molecular weight of the polypropylene glycol glyceryl ether is preferably 300 to 3,500, more preferably 500 to 1,500. If the average molecular weight is less than 300, the unexposed areas may be eluted into the developer, and if the average molecular weight is more than 3,500, the exposed areas tend to be difficult to be eluted into the developer.
By containing polypropylene glycol glyceryl ether, (c) the positive photosensitive resist layer can be softened without impairing the photosensitive characteristics and development characteristics such as sensitivity, alkali developability, and resist shape; ) It is useful because it can be successfully attached to a substrate without creating air bubbles between the positive photosensitive resist layer and the substrate.
m, n, and o in general formula (i) are all repeating unit numbers in general formula (i), and all are 0 or a natural number.

The content of polypropylene glycol glyceryl ether is preferably 1 to 30% by mass, more preferably 3 to 20% by mass, based on the total amount of novolak resin, quinonediazide sulfonic acid ester, and polypropylene glycol glyceryl ether. If the content of polypropylene glycol glyceryl ether is less than 1% by mass, the softening of the positive photosensitive resist layer (c) may be insufficient and lamination to the substrate may become difficult; if it exceeds 30% by mass, Even unexposed areas of the resist pattern may be swollen by the developer and detached from the base material.

(c) In addition to the novolak resin, quinonediazide sulfonic acid ester, and polypropylene glycol glyceryl ether, the positive photosensitive resist layer may contain other components as necessary. For example, it may contain resins such as carboxyl group-containing poly(meth)acrylate, polyurethane, vinyl acetate resin, and polyamide. By blending "other components" such as these resins, flexibility, etching solution resistance, developability, and adhesion may be improved.
In addition, solvents, colorants (dyes, pigments), photocoloring agents, photoreducing agents, thermal coloration inhibitors, fillers, antifoaming agents, flame retardants, adhesion agents, leveling agents, peeling accelerators, antioxidants. , a fragrance, a thermosetting agent, a water repellent, an oil repellent, and other additives may be contained.

The above-mentioned "other components" and "additives" can each be contained in an amount of about 0.01 to 20% by mass based on the total nonvolatile content of the positive photosensitive resist layer (c). These components may be used alone or in combination of two or more.

(c) The thickness of the positive photosensitive resist layer is preferably 1 to 20 μm, more preferably 2 to 10 μm, even more preferably 3 to 8 μm, and particularly preferably 4 to 6 μm. If it is less than 1 μm, air bubbles may easily enter when bonding by thermocompression to a base material. Furthermore, problems such as thickness unevenness and pinholes are likely to occur when a film is formed. On the other hand, if it is thicker than 20 μm, the light will not reach the bottom of the positive photosensitive resist layer (c) during exposure, the bottom of the resist pattern will become thicker, and fine lines may not be formed.
In order to form accurate thin lines, the thickness of the positive photosensitive resist layer (c) is preferably 8 μm or less. In the present invention, a thin line refers to a line with a width of 50 μm or less. In addition, when the thickness of the positive photosensitive resist layer (c) is 8 μm or less, lines with a width of 5 μm or less can also be formed. In addition, it is possible to suppress the generation of chips from the edges when cutting or slitting the positive dry film resist, and furthermore, when the positive dry film resist is bent, (c) the positive photosensitive resist layer Cracks and peeling are less likely to occur. (c) The thickness of the positive photosensitive resist layer is the thickness after drying.

(a) A method for forming (b) a release layer on a support film, and a method for providing (c) a positive photosensitive resist layer on (b) a release layer include a roll coater and a comma coater (registered trademark). , a coating method using a gravure coater, an air knife, a die coater, a bar coater, etc.

<(d) Protective film>
In the positive dry film resist of the present invention, (c) the positive photosensitive resist layer may be covered with (d) a protective film as necessary. The protective film is provided to prevent blocking of the (c) positive photosensitive resist layer to the (a) support film when the positive dry film resist is wound. (c) the positive photosensitive resist layer on the opposite side from the body film and (b) the release layer. (d) As a protective film, one with small fish eyes is preferred. Examples include polyvinyl chloride film, polyethylene film, polypropylene film, polyester film, and the like.

(d) As the protective film, it is preferable to use a self-adhesive resin film.
The self-adhesive resin film is a film in which a base layer and an adhesive layer are formed by coextrusion. Such a self-adhesive resin film is suitable because there is less concern about product contamination due to outgas components, adhesive residue, component migration, and the like. In addition, (c) the positive photosensitive resist layer can be covered with (d) the protective film without heating.

The self-adhesive resin film consists of at least a base material layer and an adhesive layer, and the base material layer does not have self-adhesiveness, and examples of the material include those mentioned above.
In addition, as the adhesive layer, use one that can be attached to a PMMA (polymethacrylate) plate at 23°C and has an adhesive strength of 0.01 N/50 mm or more and 0.30 N/50 mm width or less. It is preferable. Examples of the adhesive layer include ethylene vinyl acetate copolymer; polyolefin such as polyethylene and polypropylene; polyamide; synthetic rubber; polyacrylate; polyurethane; and the like.
The material of the adhesive layer is designed to have self-adhesive properties by adjusting the molecular weight or adding a plasticizer. Commercially available products include, for example, Toretech (registered trademark, manufactured by Toray Film Processing Co., Ltd.), FSA (registered trademark, manufactured by Futamura Chemical Co., Ltd.), Sanitect (registered trademark, manufactured by San-A Kaken Co., Ltd.), etc. Can be mentioned.

The thickness of the self-adhesive resin film is preferably 5 to 100 μm. If the thickness of the self-adhesive resin film is less than 5 μm, it may be difficult to handle, and if it is thicker than 100 μm, it may result in increased cost, bulk in the roll, and increased mass.

<Etching method>
Next, an etching method using the positive dry film resist of the present invention will be explained in detail. First, the positive dry film resist of the present invention is attached to at least one side of a substrate by a lamination method so that (c) the positive photosensitive resist layer is in contact with the substrate. It is preferable to paste it by hand.
When the positive dry film resist of the present invention has (d) a protective film, it is attached to at least one side of a substrate after (d) the protective film is peeled off.

The base material according to the present invention is a base material on which an etching process is performed, and is determined depending on the product. In the production of printed wiring boards, lead frames, metal masks, shadow masks, semiconductor packages, electrode members, electromagnetic shields, etc., base materials containing metal are selected.
For example, "base materials containing metal" such as copper, copper alloys (titanium copper alloy, copper nickel alloy, etc.), nickel, chromium, iron, tungsten, stainless steel, iron alloys such as 42 alloy, aluminum, amorphous alloys, etc. can be used. Further, metal oxide films such as ITO and FTO can be used. Furthermore, copper-clad laminates, (non-)electrolytically plated substrates, flexible copper-clad laminates, flexible stainless steel plates, laminates, etc. used in the manufacture of printed wiring boards can be used.

A lamination method is used to attach the positive dry film resist of the present invention to at least one side of the base material. A general thermal laminator for printed circuit boards or a vacuum laminator can be used. The nip pressure, conveyance speed, and roll temperature vary depending on the base material used, but any conditions may be used as long as the adhesive can be bonded by thermocompression without bubbles or unevenness.

After applying the positive dry film resist to the substrate, (a) the support film and (b) the release layer are removed from the (c) positive photosensitive resist layer. In this case, it is preferable to remove (a) the support film and (b) the release layer at the same time. According to the present invention, as described above, (a) the support film and (b) the release layer can be simultaneously removed by peeling or the like.
However, this does not exclude a mode in which only (a) the support film is removed, and even in that case, the remaining (b) peeling layer is simultaneously removed by a developer when a resist pattern is formed by subsequent development. Can be removed.

Next, the desired pattern is exposed. Preferably, ultraviolet light is used for exposure. Exposure methods include direct laser writing, contact exposure through a photomask, projection exposure, and the like. As a light source for exposure, an ultra-high-pressure mercury lamp, a high-pressure mercury lamp, a metal halide lamp, a xenon lamp, a laser, an LED, etc. can be used.

Next, development is performed. (c) The exposed portion of the positive photosensitive resist layer is removed by development. As the developer used for development, an alkaline aqueous solution is usefully used. Examples of basic compounds used in the developer include inorganic basic compounds such as alkali metal silicate, alkali metal hydroxide, alkali metal phosphate, alkali metal carbonate, ammonium phosphate, and ammonium carbonate. ; organic basic compounds such as ethanolamine, ethylenediamine, propanediamine, triethylenetetramine, morpholine, and tetramethylammonium hydroxide; and the like.

In order to adjust the developability of the (c) positive photosensitive resist layer in the exposed area, it is necessary to adjust the concentration, temperature, spray pressure, etc. of the developer. The higher the temperature of the developer, the faster the development speed, and a temperature of 40° C. or higher is preferred. In the case of potassium hydroxide, the concentration of the basic compound in the developer is preferably 1 to 4% by mass. As the device, a dip treatment device, a shower spray device, etc. can be used.

Next, the base material is etched. In the present invention, any etching solution, device, or method may be used as long as it can dissolve and remove the base material used.
Examples of the etching solution include alkaline ammonia, sulfuric acid-hydrogen peroxide, cupric chloride, persulfate, ferric chloride, aqua regia, and the like. Further, as the apparatus and method, for example, horizontal spray etching, immersion etching, etc. can be used. These details are described in "Printed Circuit Technology Handbook" (edited by Japan Printed Circuit Industry Association, published in 1987, published by Nikkan Kogyo Shimbun).

Next, the resist is stripped using a stripping solution, but before that, the resist pattern may be exposed to ultraviolet rays. By exposing to light, (c) the positive photosensitive resist layer becomes easier to remove with a stripping solution.
As the stripping solution, an alkaline aqueous solution is usefully used. Examples of basic compounds used in the stripping solution include inorganic basic compounds such as alkali metal silicate, alkali metal hydroxide, alkali metal phosphate, alkali metal carbonate, ammonium phosphate, and ammonium carbonate. and organic basic compounds such as ethanolamine, ethylenediamine, propanediamine, triethylenetetramine, morpholine, and tetramethylammonium hydroxide.

In the resist stripping process, it is necessary to adjust the concentration, temperature, spray pressure, ultrasonic conditions, etc. of the stripping solution. The higher the temperature of the stripping solution, the faster the rate at which the positive photosensitive resist layer (c) dissolves, and a temperature of 40° C. or higher is preferable. The concentration of the basic compound in the stripping solution is preferably a concentration suitable for solubility, and when the basic compound is sodium hydroxide or potassium hydroxide, it is preferably 1 to 4% by mass. As the device, a dip treatment device, an ultrasonic device, a shower spray device, etc. can be used.

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples.

[Examples 1-1 to 1-8]
Add 95 parts by mass of water to 5 parts by mass of polyvinyl alcohol (trade name: Kuraray Poval 44-88, manufactured by Kuraray Co., Ltd., degree of saponification 87.0 to 89.0 mol%), and dissolve by stirring with warm water. , a 5% by mass polyvinyl alcohol aqueous solution (coating liquid for release layer) was obtained.
Next, using a wire bar, it was coated on a polyethylene terephthalate (PET) film ((a) support film, trade name: Diafoil (registered trademark) T100, 25 μm thick, manufactured by Mitsubishi Chemical Corporation), and It was dried at ℃ for 10 minutes to remove moisture, and a (b) release layer containing polyvinyl alcohol was provided on the PET film with a thickness of 3 μm to obtain a laminated film of (a) support film and (b) release layer. .

Next, 100 parts by mass of o-cresol novolak resin (mass average molecular weight 44,000), 24 parts by mass of o-naphthoquinonediazide sulfonic acid ester of 2,3,4-trihydroxybenzophenone, and 14 parts by mass of "Component G", A solution dissolved in 300 parts by mass of ethylene glycol monomethyl ether acetate was filtered through a membrane filter (pore size: 1 μm) to obtain coating liquids for positive photosensitive resist layers of Examples 1-1 to 1-7.

"Ingredient G"
(Example 1-1) Uniol (registered trademark) TG-330 (polypropylene glycol glyceryl ether, average molecular weight 330, manufactured by NOF Corporation)
(Example 1-2) Uniol TG-1000R (polypropylene glycol glyceryl ether, average molecular weight 1000, manufactured by NOF Corporation)
(Example 1-3) Uniol TG-3000 (polypropylene glycol glyceryl ether, average molecular weight 3000, manufactured by NOF Corporation)
(Example 1-4) Uniol D-1000 (polypropylene glycol, average molecular weight 1000, manufactured by NOF Corporation)
(Example 1-5) Uniol D-4000 (polypropylene glycol, average molecular weight 4000, manufactured by NOF Corporation)
(Example 1-6) Uniox (registered trademark) M-1000 (polyethylene glycol, average molecular weight 1000, manufactured by NOF Corporation)
(Example 1-7) PEG #600 (polyethylene glycol, average molecular weight 600, manufactured by NOF Corporation)

In addition, without containing "component G", 100 parts by mass of o-cresol novolak resin (mass average molecular weight 44,000) and 24 parts by mass of o-naphthoquinonediazide sulfonic acid ester of 2,3,4-trihydroxybenzophenone were mixed with ethylene. After dissolving in 300 parts by mass of glycol monomethyl ether acetate, this solution was filtered through a membrane filter (pore size: 1 μm) to obtain a coating liquid for a positive photosensitive resist layer of Examples 1-8.

Next, each of the positive photosensitive resist layer coating liquids described above was applied to the (b) release layer surface of the laminated film prepared above using a wire bar, dried at 90°C for 10 minutes, and the solvent was removed. A positive dry film resist having a three-layer structure ((a) support film/(b) release layer/(c) positive photosensitive resist layer) of Examples 1-1 to 1-8 was prepared. (c) The thickness of the positive photosensitive resist layer was 7 μm.

Next, on the surface of the copper layer of the polished and degreased copper-clad laminate (substrate), (c) the positive photosensitive resist layer of the positive dry film resist of Examples 1-1 to 1-8 is applied as a copper layer. It was attached so that it was in contact with the surface. At that time, a general printed circuit board laminator was used. The lamination conditions were a roll temperature of 100° C., a conveyance speed of 0.5 m/min, and a pressure of 0.2 MPa.
At that time, in Examples 1-1 to 1-7, it was possible to attach (c) a positive photosensitive resist layer to the surface of the copper layer. In Example 1-8, the copper layer did not stick firmly to the surface, and (c) air bubbles appeared between the positive photosensitive resist layer and the substrate, but it could be stuck at a roll temperature of 120°C. Ta. However, (a) wrinkles occurred at the edges of the support film.

Next, (a) the support film and (b) the release layer were peeled off from the copper-clad laminate from the interface between the (b) release layer and (c) the positive photosensitive resist layer.
Regarding Examples 1-1 to 1-8, it was possible to peel off (a) the support film and (b) the release layer from the interface between the (b) release layer and (c) the positive photosensitive resist layer. .

Next, using an ultra-high-pressure mercury lamp ultraviolet irradiation device, a test chart mask having lines and spaces of 30 μm and 60 μm was placed on the positive photosensitive resist (c) and brought into close contact with suction for exposure. Next, it was immersed in a 30° C. developer (1% by mass potassium hydroxide aqueous solution) for 80 seconds to remove the exposed portion of the (c) positive photosensitive resist layer, and development was performed. After that, it was washed with water and dried. The formed resist pattern was observed using a microscope.

As a result of observation, in all of Examples 1-1 to 1-3, lines and spaces of 30 μm were formed, and there was no remaining positive-type photosensitive resist layer (c) in the exposed area, indicating a good resist. A pattern was forming.
In Examples 1-4, 1-6, 1-7, and 1-8, resist patterns with 60 μm lines and spaces could be formed, but no 30 μm lines remained. In addition, in Example 1-5, the (c) positive-type photosensitive resist layer remained in the exposed area, but by increasing the temperature of the developer to 50°C, the remaining (c) positive-type photosensitive resist layer could be removed. A resist pattern of 60 μm lines and spaces could be formed, but no 30 μm lines remained.

Next, a 60° C. ferric chloride solution was prepared, and spraying was performed at a pressure of 0.2 MPa for about 5 minutes to etch the copper layer. Thereafter, water washing and drying were immediately carried out. Next, the entire surface was irradiated with ultraviolet rays of 300 mJ/cm ² , followed by immersion in a 40° C. stripping solution (1% by mass potassium hydroxide aqueous solution) for 3 minutes to strip the resist.
When the 30 μm and 60 μm line patterns of the copper layers of Examples 1-1 to 1-3 were observed, it was confirmed that good etching with little side etching was achieved. Furthermore, in Examples 1-4 to 1-8, when the 60 μm line pattern of the copper layer was observed, it was confirmed that etching with little side etching was similarly achieved.

As is clear from the above results, it was found that the positive dry film resist of the present invention allows for good resist pattern formation and good etching. Furthermore, (c) according to a positive dry film resist in which the positive photosensitive resist layer contains polypropylene glycol glyceryl ether, air bubbles do not enter between the positive photosensitive resist layer and the base material, and It was found that fine resist patterns can be formed.

[Examples 2-1 to 2-7]
Polyvinyl alcohol shown in Table 1 was prepared, 80 parts by mass of water was added to 5 parts by mass of polyvinyl alcohol, and dissolved by stirring with warm water to obtain an aqueous polyvinyl alcohol solution. Next, 15 parts by mass of ethanol was added to prepare a release layer coating liquid with a solid content of 5% by mass.

Examples 2-1 to 2-2 were applied to one side of a polyethylene terephthalate (PET) film ((a) support film, trade name: Diafoil (registered trademark) T100, 25 μm thick, manufactured by Mitsubishi Chemical Corporation) using a wire bar. A release layer coating solution No. 2-7 was applied and dried at 90° C. for 10 minutes to remove moisture, and then a release layer (b) (thickness: 8 μm) was provided on the PET film.

Next, 100 parts by mass of o-cresol novolac resin (mass average molecular weight 44,000) and 30 parts by mass of o-naphthoquinonediazide sulfonic acid ester of 2,3,4-trihydroxybenzophenone were mixed into ethylene glycol monomethyl ether acetate. After dissolving in 300 parts by mass, this solution was filtered through a membrane filter (pore size: 1 μm) to obtain a coating liquid for a positive photosensitive resist layer.

Next, the above coating liquid for positive photosensitive resist layer was applied with a wire bar to the (b) release layer surface of the (a) support film provided with the release layer (b), and the coating solution was heated at 80°C for 10 minutes. After drying and removing the solvent, a positive dry film resist having a three-layer structure ((a) support film/(b) release layer/(c) positive photosensitive resist layer) was produced.

(cut test)
The produced positive dry film resist was cut into a size of 10 cm x 10 cm using a cutter on a cutter mat. As a result of observing the cut edges with a microscope, no cracks were found in the (c) positive photosensitive resist layer in any of Examples 2-1 to 2-7.

Next, the (c) positive photosensitive resist layer of the positive dry film resist of Examples 2-1 to 2-7 is brought into contact with the copper layer surface of the polished and degreased copper clad laminate. It was attached by thermocompression bonding. At that time, a general printed circuit board laminator was used. The lamination conditions were a roll temperature of 110° C., a conveyance speed of 0.5 m/min, and a pressure of 0.2 MPa.

(Peeling test)
Next, the (a) support film was peeled off from the copper-clad laminate to which the positive dry film resist was attached. Regarding Examples 2-1 to 2-5, it was possible to peel off the (a) support film and (b) release layer from the interface between (b) release layer and (c) positive photosensitive resist layer. .
On the other hand, regarding Examples 2-6 to 2-7, when (a) the support film is peeled off, it peels off from the interface between (a) the support film and (b) the release layer, and (b) the release layer (c) ) remained on the positive photosensitive resist layer.

(Resist pattern reproducibility)
Next, using an ultra-high pressure mercury lamp ultraviolet irradiation device, a test chart mask having lines and spaces of 50 μm was applied on the (c) positive photosensitive resist in Examples 2-1 to 2-5, and on the positive photosensitive resist in Example 2-6. In ~2-7, it was placed on the release layer (b), brought into close contact with suction, and exposed.
Next, it was immersed in a 1% by mass potassium hydroxide aqueous solution (developer) at 40° C. for 80 seconds to remove the exposed portion of the (c) positive photosensitive resist layer, and development was performed. In Examples 2-6 and 2-7, the (b) release layer was also removed at the same time because the release layer (b) could also be removed during the development.

After that, it was washed with water and dried. When it was confirmed whether lines and spaces equivalent to those of the test chart mask could be reproduced, in Examples 2-1 to 2-5, the reproducibility was good and there were no defects on the image lines. In Examples 2-6 and 2-7, circular chipping defects occurred frequently above the edge portion of the image, which was thought to be caused by gas generation during exposure, but otherwise the results were good.

(Etching pattern reproducibility)
Next, a 60° C. ferric chloride solution was prepared, and a spray treatment was performed at a pressure of 0.2 MPa for about 5 minutes to etch the copper. Thereafter, water washing and drying were immediately carried out. Next, after irradiating the entire surface with ultraviolet rays of 300 mJ/cm ² , the resist was stripped by immersing it in a 1% by mass potassium hydroxide aqueous solution (stripping solution) at 40° C. for 3 minutes.
When the 50 μm line pattern of the copper layer was observed, there was no pattern chipping in Examples 2-1 to 2-5, and the reproducibility was good. On the other hand, in Examples 2-6 to 2-7, variations were observed in the line widths of the line patterns.

As is clear from the above results, it was found that the positive dry film resist of the present invention allows for good resist pattern formation and good etching. In particular, according to a positive dry film resist containing polyvinyl alcohol with a saponification degree of 82 mol% or more, after the positive dry film resist is thermocompression bonded to the base material, (a) the support film and (b) peeling are performed. It was found that the layer could be easily peeled off from the interface between (c) the positive photosensitive resist layer and (b) the release layer, and cracking was unlikely to occur.

[Examples 3-1 to 3-14]
Production Example: Production of o-cresol novolac resin In a 2 liter four-necked flask equipped with a stirrer and a reflux condenser, 756 parts by mass of o-cresol, 369 parts by mass of 37% by mass formalin, and p-toluene as a reaction catalyst were added. 7.52 parts by mass of sulfonic acid monohydrate was charged, and the mixture was heated to reflux temperature while stirring and mixing, and the reaction was continued under reflux for 12 hours.

Next, deliquification was started, and the temperature was raised to 230°C to perform concentration, and the temperature was further raised to 240°C at a reduced pressure of 2 kPa to perform concentration. The fraction was distilled off to obtain 600 g of solid o-cresol novolak resin with a softening point of 150°C. The weight average molecular weight of the o-cresol novolac resin obtained was 12,000.

On the other hand, an o-cresol novolac resin was produced in the same manner except that the amount of 37% by mass formalin was changed. Synthesis was performed by changing the amount of 37% by mass formalin to 397 parts by mass, 510 parts by mass, 624 parts by mass, 681 parts by mass, 695 parts by mass, and 709 parts by mass, and the mass of the o-cresol novolak resin obtained respectively. The average molecular weights were measured and were 18,000, 25,000, 44,000, 58,000, 71,000, and 80,000.

Next, 95 parts by mass of water is added to 5 parts by mass of polyvinyl alcohol (trade name: Kuraray Poval 44-88, manufactured by Kuraray Co., Ltd., degree of saponification 87.0 to 89.0 mol%), and the mixture is stirred with warm water. to obtain a 5% by mass polyvinyl alcohol aqueous solution (coating liquid for release layer). Next, it was coated on a polyethylene terephthalate (PET) film ((a) support film, trade name: Diafoil (registered trademark) T100, 25 μm thick, manufactured by Mitsubishi Chemical Corporation) using a wire bar and heated to 90°C. The film was dried for 10 minutes to remove moisture, and a (b) release layer containing polyvinyl alcohol was provided on the PET film with a thickness of 3 μm to obtain a laminated film of the (a) support film and (b) release layer. (Laminated film 1).

Further, a release layer coating liquid was prepared by adding 0.7 parts by mass of polyethylene glycol #600 to 100 parts by mass of the 5% by mass aqueous polyvinyl alcohol solution. Next, it was coated on a PET film ((a) support film, trade name: Diafoil (registered trademark) T100, 25 μm thick, manufactured by Mitsubishi Chemical Corporation) using a wire bar, and dried at 90°C for 10 minutes. Then, moisture was removed, and a (b) release layer containing polyvinyl alcohol and polyethylene glycol was provided on the PET film with a thickness of 3 μm to obtain a laminated film of (a) support film and (b) release layer ( Laminated film 2).

Next, 100 parts by mass of the o-cresol novolac resin having each of the above mass average molecular weights and 30 parts by mass of o-naphthoquinonediazide sulfonic acid ester of 2,3,4-trihydroxybenzophenone were added to 300 parts by mass of ethylene glycol monomethyl ether acetate. After dissolving, this solution was filtered through a membrane filter (pore size: 1 μm) to obtain a coating liquid for each positive photosensitive resist layer.

Next, each of the positive photosensitive resist layer coating liquids described above was applied to the (b) release layer surface of the laminated film 1 and laminated film 2 prepared above using a wire bar, and dried at 90°C for 10 minutes. The solvent was removed to produce a positive dry film resist having a three-layer structure ((a) support film/(b) release layer/(c) positive photosensitive resist layer). Table 2 shows the relationship between the laminated film and the o-cresol novolac resin in the positive dry film resist of each example.

Next, the produced positive dry film resist was cut on a cutter mat into a size of 10 cm x 10 cm using a cutter. As a result of observing the cut ends with a microscope, no cracking occurred in Examples 3-1 to 3-10, but in Examples 3-11 to 3-14, cracking occurred within a range of 500 μm from the edge. , (c) Cracks had occurred in the positive photosensitive resist layer.

Next, (c) the positive photosensitive resist layer of the positive dry film resist of Examples 3-1 to 3-14 is brought into contact with the surface of the copper layer of the polished and degreased copper clad laminate. I pasted it like this. At that time, a general printed circuit board laminator was used. The lamination conditions were a roll temperature of 110° C., a conveyance speed of 0.5 m/min, and a pressure of 0.2 MPa. Next, (a) the support film and (b) the release layer were peeled off from the copper-clad laminate from the interface between the (b) release layer and (c) the positive photosensitive resist layer. All were able to be peeled off successfully.

Next, using an ultra-high pressure mercury lamp ultraviolet irradiation device, a test chart mask having lines and spaces of 50 μm was placed on the positive photosensitive resist layer (c) and brought into close contact with suction for exposure.
Next, it was immersed in a developer (1% by mass potassium hydroxide aqueous solution) at 30° C. for 80 seconds, and (c) the exposed portion of the positive photosensitive resist layer was removed and developed. After that, it was washed with water and dried.

When it was checked whether lines and spaces equivalent to those of the test chart mask could be reproduced (resist pattern reproducibility), the reproducibility was good in all of Examples 3-1 to 3-14.

Next, a 60° C. ferric chloride solution was prepared, and spraying was performed at a pressure of 0.2 MPa for about 5 minutes to etch the copper layer. Thereafter, water washing and drying were immediately carried out. Next, the entire surface was irradiated with ultraviolet rays of 300 mJ/cm ² , and then immersed in an alkaline stripping solution (1 mass % potassium hydroxide aqueous solution) at 40° C. for 3 minutes to strip the resist. A 50 μm line pattern of the copper layer was observed, and the line width after etching was measured.

Table 3 shows the results of measuring the line width of the pattern after etching at four points. In Examples 3-1 to 3-10, the line width was within the range of 45 to 48 μm, and it was confirmed that good etching with little side etching was achieved. In Examples 3-11 to 3-14, the line width was 41 to 47 μm, and the variation in line width was large and side etching was large.

As is clear from the above results, it was found that the positive dry film resist of the present invention allows for good resist pattern formation. In particular, in the case of a positive dry film resist in which the novolak resin contains an o-cresol novolak resin with a mass average molecular weight (Mw) of 16,000 to 75,000, and the quinonediazide sulfonic acid ester contains a naphthoquinonediazide sulfonic acid ester, the edges are cut off when cutting. It has been found that it is difficult to generate debris and that it is possible to perform good etching with little variation in line width during etching.

[Examples 4-1 to 4-12]
Prepare polyvinyl alcohol (trade name: Kuraray Poval 44-88, degree of saponification 87.0 to 89.0 mol%), add 95 parts by mass of water to 5 parts by mass, and dissolve the polyvinyl alcohol by stirring with warm water. An alcohol aqueous solution (coating liquid for release layer) was obtained.

One side of a polyethylene terephthalate (PET) film ((a) support film, trade name: Diafoil (registered trademark) T100, 25 μm thick, manufactured by Mitsubishi Chemical Corporation) was subjected to corona discharge treatment in cases other than Example 4-8. (Examples 4-1 to 4-12). The amount of corona discharge was 15 W·min/m ² .
Next, the above polyvinyl alcohol aqueous solution was applied to the corona discharge treated surface of the (a) support film using a wire bar, and dried at 90°C for 10 minutes to remove moisture. A release layer (b) was provided on top. (b) The thickness of the release layer is shown in Table 4.

As a result of observing the (b) release layer under a microscope, pinhole defects were found in a part of the (b) release layer of Examples 4-9. In addition, there were bubbles in a part of the release layer (b) of Example 4-10.

Next, 100 parts by mass of o-cresol novolac resin (mass average molecular weight 44,000) and 30 parts by mass of o-naphthoquinonediazide sulfonic acid ester of 2,3,4-trihydroxybenzophenone were mixed with 300 parts by mass of ethylene glycol monomethyl ether acetate. After dissolving in parts by mass, this solution was filtered through a membrane filter (pore size: 1 μm) to obtain a coating liquid for a positive photosensitive resist layer.

Next, the above coating liquid for positive photosensitive resist layer was applied with a wire bar to the (b) release layer surface of the (a) support film provided with the release layer (b), and the coating solution was heated at 80°C for 10 minutes. After drying and removing the solvent, a positive dry film resist having a three-layer structure ((a) support film/(b) release layer/(c) positive photosensitive resist layer) was produced. (c) Table 4 shows the film thickness of the positive photosensitive resist layer.

(cut test)
The produced positive dry film resist was cut into a size of 10 cm x 10 cm using a cutter on a cutter mat. As a result of observing the cut ends under a microscope, no cracks were observed in the positive photosensitive resist layer (c) in any of Examples 4-1 to 4-11. In Example 4-12, (c) the positive photosensitive resist layer had some large cracks, which could generate chips and cause problems such as contamination.

Next, the (c) positive photosensitive resist layer of the positive dry film resist of Examples 4-1 to 4-12 is brought into contact with the copper layer surface of the polished and degreased copper-clad laminate. It was attached by thermocompression using the laminating method. At that time, a general printed circuit board laminator was used. The lamination conditions were a roll temperature of 110° C., a conveyance speed of 0.5 m/min, and a pressure of 0.2 MPa.

Next, (a) the support film and (b) the release layer were peeled off from the copper-clad laminate to which the positive dry film resist was attached. In Examples 4-1 to 4-7, (a) the support film and (b) the release layer could be simultaneously peeled off from the interface between the (b) release layer and (c) the positive photosensitive resist layer. Ta.
On the other hand, in Example 4-8, when (a) the support film is peeled off, it peels off from the interface between (a) the support film and (b) the release layer, and (b) the release layer is removed from the (c) positive photosensitive remained on the resist layer. Furthermore, in Examples 4-9 and 4-10, pinhole defects occurred in the (c) positive photosensitive resist layer on the (b) release layer containing pinholes and air bubbles. Further, in Example 4-11, (c) the positive type photosensitive resist was not sufficiently pressure-bonded to the copper clad laminate, and a portion of the positive dry film resist was peeled off from the copper clad laminate.

(Resist pattern reproducibility)
Next, using an ultra-high pressure mercury lamp ultraviolet irradiation device, a test chart mask having lines and spaces of 50 μm was applied to (c) positive photosensitive resist in Examples 4-1 to 4-7, 4-9 and 4-10. In Example 4-8, the film was placed on the release layer (b), brought into close contact with suction, and exposed.
Next, it is immersed in a 1% by mass potassium hydroxide aqueous solution (developer) at 40°C for 80 seconds, and (c) the exposed area of the positive photosensitive resist layer is removed and developed to form a resist pattern. Formed. In Example 4-8, the release layer (b) was also removed at the same time during development. After that, it was washed with water and dried.

When it was confirmed whether lines and spaces equivalent to those of the test chart mask could be reproduced, in Examples 4-1 to 4-7, the reproducibility was good and there were no defects on the image lines. In Example 4-8, there was a circular chipping defect above the edge portion of the image, which is thought to be caused by gas generation during exposure. Furthermore, in Examples 4-9 and 4-10, pinhole defects occurred in (c) the positive photosensitive resist layer.

(Etching pattern reproducibility)
Next, a 60° C. ferric chloride solution was prepared, and a spray treatment was performed at a pressure of 0.2 MPa for about 5 minutes to etch the copper. Thereafter, it was immediately washed with water and dried. Next, after irradiating the entire surface with ultraviolet rays of 300 mJ/cm ² , the resist was stripped by immersing it in a 1% by mass potassium hydroxide aqueous solution (stripping solution) at 40° C. for 3 minutes.
When the 50 μm line pattern of the copper layer was observed, there was no pattern chipping in Examples 4-1 to 4-7, and the reproducibility was good.

As is clear from the above results, it was found that resist pattern formation and etching were both possible with the positive dry film resist of the present invention.
In particular, (a) corona discharge treatment is applied to the (b) release layer side of the support film, (b) the release layer has a thickness of 1 to 4 μm, and (c) a positive photosensitive resist layer. In a positive dry film resist having a thickness of 3 to 8 μm, the support film and release layer can be more easily peeled off at the same time from the interface between the positive photosensitive resist layer and the release layer after thermocompression bonding to the substrate. was completed. Furthermore, when cutting or slitting the positive dry film resist, chips were particularly difficult to generate from the edges. Furthermore, pinhole defects were particularly unlikely to occur.

[Examples 5-1 to 5-6]
Add 95 parts by mass of water to 5 parts by mass of polyvinyl alcohol (trade name: Kuraray Poval 44-88, manufactured by Kuraray Co., Ltd., degree of saponification 87.0 to 89.0 mol%), and dissolve by stirring with warm water. , a 5% by mass polyvinyl alcohol aqueous solution (coating liquid for release layer) was obtained.
Next, it was coated on a polyethylene terephthalate (PET) film ((a) support film, trade name: Diafoil (registered trademark) T100, 25 μm thick, manufactured by Mitsubishi Chemical Corporation) using a wire bar and heated to 90°C. The film was dried for 10 minutes to remove moisture, and a (b) release layer containing polyvinyl alcohol was provided on the PET film with a thickness of 3 μm to obtain a laminated film of the (a) support film and (b) release layer. .

Next, 100 parts by mass of o-cresol novolak resin (mass average molecular weight 44,000), 30 parts by mass of o-naphthoquinonediazide sulfonic acid ester of 2,3,4-trihydroxybenzophenone, and 300 parts by mass of propylene glycol monomethyl ether acetate. This solution was filtered through a membrane filter (pore size: 1 μm) to obtain (c) a coating liquid for a positive photosensitive resist layer.

Next, on the (b) release layer surface of the laminated film prepared above, the coating liquid for the positive photosensitive resist layer (c) was applied using a wire bar, dried at 90°C for 10 minutes, and then was removed. In order to form a (d) protective film on the surface of the formed (c) positive photosensitive resist layer, the following (d) protective film was prepared.

"(d) Protective film"
(Example 5-1) Toretech (registered trademark) 7332 (self-adhesive resin film, manufactured by Toray Film Processing Co., Ltd.)
(Example 5-2) Toretec 7832C (self-adhesive resin film, manufactured by Toray Film Processing Co., Ltd.)
(Example 5-3) Toretec 7H52 (self-adhesive resin film, manufactured by Toray Film Processing Co., Ltd.)
(Example 5-4) FSA (registered trademark) 010M (self-adhesive resin film, manufactured by Futamura Chemical Co., Ltd.)
(Example 5-5) GF1 (registered trademark) (polyethylene film, manufactured by Tamapoly Co., Ltd.)
(Example 5-6) Alphan (registered trademark) FG-201 (polypropylene film, manufactured by Oji F-Tex Co., Ltd.)

The above protective film (d) was attached to the surface of the positive photosensitive resist layer (c) using a rubber roller. At that time, a general printed circuit board laminator was used. The lamination conditions were a roll temperature of 25° C., a conveyance speed of 0.5 m/min, and a pressure of 0.2 MPa.

The (d) protective films of Examples 5-1 to 5-4 were free from bubbles and wrinkles and could be applied neatly. On the other hand, Examples 5-5 and 5-6 could not be pasted at room temperature. Therefore, it was possible to attach the film by raising the lamination temperature to 80° C., but wrinkles were generated in the protective film (d) due to heat shrinkage, and it was not possible to attach the film neatly.

Ten sheets of the positive dry film resists of Examples 5-1 to 5-4 with the (d) protective film attached were stacked and stored at room temperature for 3 months, but no blocking occurred. Furthermore, even when the (d) protective film was peeled off, the (c) protective film could be peeled off cleanly without peeling between the (c) positive photosensitive resist layer and the (b) release layer. Furthermore, when the surface of the positive photosensitive resist layer (c) after peeling off the protective film (d) was observed, no adhesive residue was observed.

Further, the positive dry film resist was cut into a size of 10 cm x 10 cm using a cutter. When the cut surfaces were observed, no chips were found in the positive dry film resists of Examples 5-1 to 5-4. On the other hand, when (d) cutting was performed without attaching the protective film, chips derived from the (c) positive photosensitive resist layer were likely to be generated.

Next, after peeling off the (d) protective film of the positive dry film resist of Examples 5-1 to 5-4 above on the surface of the copper layer of the polished and degreased copper-clad laminate, (c) the positive photosensitive The photoresist layer was attached so as to be in contact with the surface of the copper layer. At that time, a general printed circuit board laminator was used. The laminating conditions were a roll temperature of 100° C., a conveyance speed of 0.5 m/min, and a pressure of 0.2 MPa, and it was possible to adhere the layer to the surface of the copper layer.

Next, (a) the support film and (b) the release layer were peeled off from the copper-clad laminate from the interface between the (b) release layer and (c) the positive photosensitive resist layer. In all of Examples 5-1 to 5-6, (a) the support film could be peeled off from the interface with (b) the release layer.

Next, using an ultra-high-pressure mercury lamp ultraviolet irradiation device, a test chart mask having lines and spaces of 30 μm was placed over the release layer (b), brought into close contact with suction, and exposed.
Next, the developer (1% by mass potassium hydroxide aqueous solution) was immersed for 80 seconds at 30°C to remove (b) the release layer and at the same time (c) remove the exposed portion of the positive photosensitive resist layer. Then, I developed it. After that, it was washed with water and dried. The formed resist pattern was observed using a microscope.

As a result of observation, in all of Examples 5-1 to 5-4, lines and spaces of 30 μm were formed, and there was no remaining positive photosensitive resist layer (c) in the exposed area, which was good. .
Next, a 60° C. ferric chloride solution was prepared, and spraying was performed at a pressure of 0.2 MPa for about 5 minutes to etch the copper layer. Thereafter, water washing and drying were immediately carried out. Next, the entire surface was irradiated with ultraviolet rays of 300 mJ/cm ² , and then immersed in an alkaline stripping solution (1 mass % potassium hydroxide aqueous solution) at 40° C. for 3 minutes to strip the resist.
When the 50 μm line pattern of the copper layer was observed, it was confirmed that good etching with little side etching was achieved in all of Examples 5-1 to 5-4.

As is clear from the above results, when the positive dry film resist of the present invention has (d) a protective film, and (d) the protective film is made of a self-adhesive resin film, it is possible to obtain a brittle positive-working photosensitive resist film. It was found that even when the layer is slit or cut, chips are not easily generated, and furthermore, blocking is not easily generated between the support film and the positive photosensitive resist layer.

[Comparative example 1]
<(b) Positive dry film resist without laminated release layer>
100 parts by mass of o-cresol novolac resin (mass average molecular weight 44000), 24 parts by mass of o-naphthoquinonediazide sulfonic acid ester of 2,3,4-trihydroxybenzophenone, and Uniol TG-1000R (polypropylene glycol glyceryl ether, average molecular weight A solution in which 14 parts by mass of 1000 (manufactured by NOF Corporation) was dissolved in 300 parts by mass of ethylene glycol monomethyl ether acetate was filtered through a membrane filter (pore size 1 μm) to prepare (c) a coating for a positive photosensitive resist layer. A working solution was obtained.

Next, using a wire bar, the (c) positive type A coating solution for a photosensitive resist layer is applied, dried at 90°C for 10 minutes, the solvent component is removed, and a two-layer structure ((a) support film/(c) positive photosensitive resist layer) is formed. ) A positive dry film resist was prepared. (c) The thickness of the positive photosensitive resist layer was 7 μm.

Next, the positive photosensitive resist layer (c) of the positive dry film resist was attached to the copper layer surface of the polished and degreased copper clad laminate (substrate) so that it was in contact with the copper layer surface. At that time, a general printed circuit board laminator was used. The lamination conditions were a roll temperature of 100° C., a conveyance speed of 0.5 m/min, and a pressure of 0.2 MPa.

An attempt was made to peel off the (a) support film from the (c) positive photosensitive resist layer, but the film was firmly adhered to the film and could not be peeled off. If an attempt was made to forcibly peel it off, cohesive failure occurred within the positive photosensitive resist layer (c), and the next exposure step could not be proceeded to. (b) It was found that in a positive dry film resist on which a release layer was not laminated, (a) the support film had poor releasability and could not be used.

[Comparative example 2]
<Positive dry film resist containing no polyvinyl alcohol and laminated with (b) release layer>
40 parts by mass of a carboxyl group-containing acrylic copolymer (mass average molecular weight 100,000) obtained by copolymerizing methyl methacrylate/n-butyl acrylate/methacrylic acid at a mass ratio of 63/15/22, and 10 parts by mass of polyethylene glycol. 600 and 50 parts by mass of propylene glycol monomethyl ether were stirred and mixed to obtain a solution for an acrylic resin layer.
Next, the obtained acrylic resin layer solution was applied to a polyethylene terephthalate (PET) film ((a) support film, trade name: Diafoil (registered trademark) T100, 25 μm thick, manufactured by Mitsubishi Chemical Corporation) using a wire bar. (manufactured by the company), dried at 90°C for 10 minutes, removed the solvent component, provided (b) a release layer made of acrylic resin with a thickness of 3 μm on the PET film, and (a) supported film. and (b) a laminated film with a release layer was obtained.

Next, 100 parts by mass of o-cresol novolak resin (mass average molecular weight 44,000), 24 parts by mass of o-naphthoquinonediazide sulfonic acid ester of 2,3,4-trihydroxybenzophenone, and Uniol TG-1000R (polypropylene glycol glyceryl ether) were added. , average molecular weight 1000, manufactured by NOF Corporation) dissolved in 300 parts by mass of ethylene glycol monomethyl ether acetate was filtered through a membrane filter (pore size 1 μm) to obtain (c) positive photosensitive resist. A coating solution for the layer was obtained.

Next, the above-mentioned coating solution for each (c) positive photosensitive resist layer was applied to the (b) release layer surface of the laminated film prepared above using a wire bar, and dried at 90°C for 10 minutes. The solvent was removed to produce a positive dry film resist having a three-layer structure ((a) support film/(b) release layer/(c) positive photosensitive resist layer). (c) The thickness of the positive photosensitive resist layer was 7 μm.

When held by hand before being attached to a copper-clad laminate, cracks occurred in the positive dry film resist even when it was slightly bent. Further, the positive photosensitive resist layer (c) was detached from the release layer (b) over a large area, and could not be used.

The positive dry film resist of the present invention can be used in the production of printed wiring boards, lead frames, metal masks, shadow masks, semiconductor packages, electrode members, electromagnetic shielding, etc., during metal processing by etching and plating of metal base materials. Can be used as a resist.

(a) Support film (b) Peeling layer (c) Positive photosensitive resist layer (d) Protective film

Claims (9)

At least (a) a support film, (b) a release layer, and (c) a positive photosensitive resist layer are laminated in this order, (b) the release layer contains polyvinyl alcohol, and (c) a positive photosensitive resist layer is formed. A positive dry film resist characterized in that the type photosensitive resist layer contains a novolac resin and a quinonediazide sulfonic acid ester as main components (provided that a thermoplastic resin is used between (a) the support film and (b) the release layer). (excluding cases in which a resin layer is included, cases in which a release layer is provided between (a) a support film and (b) a release layer, and cases in which (b) a release layer contains polysilicon). (b) The positive dry film resist according to claim 1, wherein the content of polyvinyl alcohol is 80% by mass or more based on the total nonvolatile content of the release layer. The positive dry film resist according to claim 1 or 2, wherein (c) the positive photosensitive resist layer contains polypropylene glycol glyceryl ether. The positive dry film resist according to any one of claims 1 to 3, wherein the novolak resin contains an o-cresol novolac resin having a mass average molecular weight (Mw) of 16,000 to 75,000, and the quinonediazide sulfonic acid ester contains a naphthoquinonediazide sulfonic acid ester. . The positive dry film resist according to any one of claims 1 to 4, wherein the polyvinyl alcohol contains polyvinyl alcohol with a saponification degree of 82 mol% or more. (a) Corona discharge treatment is applied to the (b) release layer side of the support film, (b) the release layer has a thickness of 1 to 4 μm, and (c) the positive photosensitive resist layer has a thickness of The positive dry film resist according to any one of claims 1 to 5, which has a diameter of 3 to 8 μm. At least (a) a support film, (b) a release layer, (c) a positive photosensitive resist layer, and (d) a protective film are laminated in this order, and (d) the protective film is made of a self-adhesive resin film. The positive dry film resist according to any one of claims 1 to 6. (c) a positive photosensitive resist layer of the positive dry film resist according to any one of claims 1 to 6 is attached to at least one side of the base material by a lamination method, and (a) a support film and (b) peeled off. simultaneously removing the layers, then exposing the desired pattern, then developing (c) the positive-working photosensitive resist layer with a developer to form a resist pattern, then etching the substrate, and then An etching method that removes resist using a remover. After peeling off the protective film (d) of the positive dry film resist according to claim 7, attaching (c) the positive photosensitive resist layer of the positive dry film resist to at least one side of the substrate by a lamination method, (a) simultaneously removing the support film and (b) the release layer, then exposing the desired pattern to light, and then developing (c) the positive photosensitive resist layer with a developer to form a resist pattern; An etching method in which the base material is then etched, and then the resist is removed using a remover.

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