JP7625791B2 - Base film, dry film resist including base film, and exposure method - Google Patents

Description

Embodiments of the present disclosure relate to a base film, a dry film resist including the base film, and an exposure method.

A known method for forming pixels in an organic EL display device is to form pixels using a deposition mask that includes through-holes. A known method for manufacturing a deposition mask is to form through-holes in a metal plate by etching. For example, first, a dry film resist is attached to the metal plate. Next, the resist layer of the dry film resist is exposed and developed to partially remove the resist layer. Next, the metal plate is etched using the remaining resist layer as a mask to form through-holes in the metal plate.

JP 2019-81962 A

The embodiment of the present disclosure aims to provide a dry film resist and a base film for the dry film resist that can improve the accuracy of exposure and development.

According to one embodiment of the present disclosure, a base film used in a dry film resist having a resist layer includes at least a base layer containing plastic. The arithmetic mean roughness of a first surface of the base film that is located on the opposite side to the resist layer is 0.01 nm or more and 0.2 nm or less.

This disclosure makes it possible to improve the accuracy of exposure and development.

FIG. 2 is a cross-sectional view showing an example of a dry film resist according to an embodiment of the present disclosure. 2 is an enlarged cross-sectional view showing an example of a base film of the dry film resist of FIG. 1. FIG. 2 is a side view showing an example of a base film in a wound state. FIG. 2 is an enlarged cross-sectional view showing a portion of the base film in a wound state. FIG. 2 is a side view showing an example of a dry film resist in a rolled up state. 2 is an enlarged cross-sectional view showing a portion of the dry film resist in a wound state. FIG. 1 is a cross-sectional view showing an example of a process for attaching a dry film resist to a metal plate. 1 is a cross-sectional view showing an example of a process of exposing a dry film resist using an exposure mask. FIG. 2 is a plan view showing an example of an exposure mask. 1 is a cross-sectional view showing an example of a process for developing a dry film resist. FIG. 1 is a cross-sectional view showing an example of a deposition mask produced by etching a metal plate. 1 is a cross-sectional view showing an example of a process for attaching a dry film resist to a metal plate. 1 is a cross-sectional view showing an example of a process of exposing and developing a dry film resist. FIG. 1 is a cross-sectional view showing an example of a deposition mask produced by etching a metal plate. FIG. 2 is a cross-sectional view showing an example of a dry film resist according to an embodiment of the present disclosure. 16 is an enlarged cross-sectional view showing an example of a base film of the dry film resist of FIG. 15. FIG. 1 is a diagram showing the evaluation results of Examples 1 to 6 and Comparative Examples 1 and 2. FIG. 1 is a diagram showing the evaluation results of Examples 7 to 12 and Comparative Example 3.

In this specification and drawings, unless otherwise specified, terms that refer to the materials that form the basis of a certain structure, such as "substrate," "base material," "plate," "sheet," and "film," are not to be distinguished from one another solely on the basis of differences in name.

Unless otherwise specified, in this specification and drawings, terms that specify shapes, geometric conditions, and the extent of those conditions, such as "parallel" and "orthogonal," and values of lengths and angles, are to be interpreted without being bound by strict meanings, but rather to include the range within which similar functions can be expected.

In this specification and drawings, unless otherwise specified, when a certain configuration such as a certain member or a certain region is described as being "on" or "under", "upper" or "lower" or "above" or "below" another configuration such as another member or another region, this includes the case where the certain configuration is in direct contact with the other configuration. It also includes the case where another configuration is included between a certain configuration and the other configuration, that is, where the configuration is indirectly in contact. Also, unless otherwise specified, the words "on", "upper side", "upper", or "lower", or "lower", "lower" and "lower" may be used in the up-down direction.

In this specification and drawings, unless otherwise specified, identical parts or parts having similar functions are given the same or similar symbols, and repeated explanations may be omitted. In addition, the dimensional ratios of the drawings may differ from the actual ratios for the convenience of explanation, and some components may be omitted from the drawings.

Unless otherwise specified in this specification and drawings, one embodiment of this specification may be combined with other embodiments to the extent that no contradictions arise. In addition, other embodiments may be combined with each other to the extent that no contradictions arise.

Unless otherwise specified in this specification and drawings, when multiple steps are disclosed in a method such as a manufacturing method, other steps that are not disclosed may be performed between the disclosed steps. In addition, the order of the disclosed steps is arbitrary to the extent that no contradiction occurs.

In this specification and drawings, unless otherwise specified, a numerical range expressed by the symbol "to" includes the numerical values before and after the symbol. For example, the numerical range defined by the expression "34 to 38% by mass" is the same as the numerical range defined by the expression "34% by mass or more and 38% by mass or less."

One embodiment of the present disclosure will be described in detail below with reference to the drawings. Note that the embodiment described below is an example of an embodiment of the present disclosure, and the present disclosure should not be interpreted as being limited to only these embodiments.

A first aspect of the present disclosure is a base film for use in a dry film resist having a resist layer, comprising:
at least a base layer comprising plastic;
The base film has a first surface, which is located on the opposite side to the resist layer, having an arithmetic mean roughness of 0.01 nm or more and 0.2 nm or less.

A second aspect of the present disclosure is a base film according to the first aspect described above,
The base film may have a haze of 1.0% or less.

A third aspect of the present disclosure is a base film according to the first aspect or the second aspect,
The base film may have a total light transmittance of 90% or more.

A fourth aspect of the present disclosure is a base film according to each of the first to third aspects described above,
The base film may have a thickness of 8 μm or more and 24 μm or less.

A fifth aspect of the present disclosure is a base film according to any one of the first to third aspects described above,
The thickness of the base film may be 12 μm or more and 16 μm or less.

A sixth aspect of the present disclosure is a base film according to any one of the first to fifth aspects described above,
a surface layer located on the base layer and constituting the first surface of the base film;
the surface layer comprises a binder and particles;
The particles in the surface layer may have an average particle size of 50 nm or less.

A seventh aspect of the present disclosure is a base film according to the sixth aspect,
The surface layer may have a thickness of 1.0 μm or less.

An eighth aspect of the present disclosure is a base film according to the sixth aspect or the seventh aspect,
The particles of the surface layer may comprise silica.

A ninth aspect of the present disclosure is a base film according to each of the first to eighth aspects described above,
A surface of the base layer may constitute the first surface of the base film.

A tenth aspect of the present disclosure is a dry film resist, comprising:
A base film according to any one of the first to eighth aspects described above;
and a resist layer on a second surface of the base film opposite the first surface.

An eleventh aspect of the present disclosure is a dry film resist according to the tenth aspect,
The resist layer may have a thickness of 5 μm or more and 15 μm or less.

A twelfth aspect of the present disclosure is a dry film resist according to the tenth aspect or the eleventh aspect,
A protective film for protecting the resist layer may be provided.

A thirteenth aspect of the present disclosure is a dry film resist according to any one of the twelfth aspects described above,
The protective film may comprise polyethylene.

A fourteenth aspect of the present disclosure is a dry film resist according to the twelfth aspect or the thirteenth aspect,
The protective film may have a thickness of 20 μm or more and 50 μm or less.

A fifteenth aspect of the present disclosure is a dry film resist according to any one of the twelfth aspect to the fourteenth aspect,
The protective film may have a static friction coefficient of 0.30 or less.

A sixteenth aspect of the present disclosure is an exposure method, comprising:
A step of attaching the resist layer of the dry film resist according to any one of the tenth aspect to the fifteenth aspect to a metal plate;
and irradiating the resist layer with light through a light-transmitting region of an exposure mask including a light-transmitting region and a light-shielding region.

A seventeenth aspect of the present disclosure is an exposure method according to the sixteenth aspect, comprising:
The light shielding region of the exposure mask may have a dimension of 30 μm or less.

An eighteenth aspect of the present disclosure is an exposure method according to the sixteenth aspect or the seventeenth aspect,
The metal plate may have a thickness of 30 μm or less.

One embodiment of the present disclosure will be described in detail below with reference to the drawings. Note that the embodiment described below is an example of an embodiment of the present disclosure, and the present disclosure should not be interpreted as being limited to only these embodiments.

FIG. 1 is a cross-sectional view showing an example of a dry film resist 50. The dry film resist 50 includes a first surface 501 and a second surface 502 located on the opposite side of the first surface 501. The dry film resist 50 may include a base film 55 and a resist layer 51 located closer to the second surface 502 than the base film 55.

The base film 55 includes a first surface 551 located on the side opposite to the resist layer 51, and a second surface 552 located on the resist layer 51 side. As shown in FIG. 1, the first surface 551 of the base film 55 may constitute the first surface 501 of the dry film resist 50. In addition, the second surface 552 of the base film 55 may be in contact with the resist layer 51.

The dry film resist 50 may include a protective film 52 located closer to the second surface 502 than the resist layer 51. As shown in FIG. 1, the protective film 52 may constitute the second surface 502 of the dry film resist 50.

Each component of the dry film resist 50 will be described in detail.

First, the base film 55 will be described. The base film 55 is a member for supporting the resist layer 51. As described below, the exposure process for exposing the resist layer 51 is carried out in a state in which the base film 55 is attached to the resist layer 51. In this case, the light for exposing the resist layer 51 reaches the resist layer 51 after passing through the base film 55. For this reason, the base film 55 is required to be transparent.

Haze can be used as an index of transparency of a film such as the base film 55. Haze is the ratio of diffuse transmittance to total light transmittance. The haze of the base film 55 may be, for example, 0.1% or more, 0.2% or more, 0.3% or more, or 0.5% or more. The haze of the base film 55 may be, for example, 0.7% or less, 0.8% or less, 0.9% or less, or 1.0% or less. By making the haze of the base film 55 1.00% or less, it is possible to suppress scattering of light for exposing the resist layer 51 while passing through the base film 55. This makes it possible to improve the positional accuracy of the exposure.

The haze range of the base film 55 may be determined by a first group consisting of 0.1%, 0.2%, 0.3%, and 0.5%, and/or a second group consisting of 0.7%, 0.8%, 0.9%, and 1.0%. The haze range of the base film 55 may be determined by a combination of any one of the values included in the first group described above and any one of the values included in the second group described above. The haze range of the base film 55 may be determined by a combination of any two of the values included in the first group described above. The haze range of the base film 55 may be determined by a combination of any two of the values included in the second group described above. For example, it may be 0.1% or more and 1.0% or less, 0.1% or more and 0.9% or less, 0.1% or more and 0.8% or less, 0.1% or more and 0.7% or less, 0.1% or more and 0.5% or less, 0.1% or more and 0.3% or less, 0.1% or more and 0.2% or less, 0.2% or more and 1.0% or less, 0.2% or more and 0.9% or less, 0.2% or more and 0.8% or less, 0.2% or more and 0.7% or less, 0.2% or more and 0.5% or less, 0.2% or more and 0.3% or less, or 0.3% or more and 1.0% or less. Alternatively, it may be 0.3% or more and 0.9% or less, 0.3% or more and 0.8% or less, 0.3% or more and 0.7% or less, 0.3% or more and 0.5% or less, 0.5% or more and 1.0% or less, 0.5% or more and 0.9% or less, 0.5% or more and 0.8% or less, 0.5% or more and 0.7% or less, 0.7% or more and 1.0% or less, 0.7% or more and 0.9% or less, 0.7% or more and 0.8% or less, 0.8% or more and 1.0% or less, 0.8% or more and 0.9% or less, or 0.9% or more and 1.0% or less.

The method for measuring the haze of the base film 55 will be described. First, a base film 55 having a length of 700 mm is prepared. Next, the base film 55 is divided into thirds in the width direction to create three films. Next, a part of each film is cut to create three samples having a width of 50 mm and a length of 100 mm. Each sample includes the center of each film in the longitudinal direction. Next, the samples are placed in a haze meter so that the first surface 551 is located on the light source side, and the haze is measured by a method conforming to JIS K7136:2000. As the haze meter, a haze meter HM-150 manufactured by Murakami Color Research Laboratory Co., Ltd. is used.

For each sample, haze measurements are performed at three different locations. Therefore, when three samples are used, haze measurement results are obtained at nine different locations. The average value A of the measurement results at the nine locations is used as the haze of the base film 55.

The standard deviation B of the haze measured at nine locations may be calculated. It is preferable that the haze value taking into account variation, calculated from the average haze value A and standard deviation B, is within the haze range defined by the first and second groups described above. For example, it is preferable that both "A+2×B" and "A-2×B" are within the haze range defined by the first and second groups described above. When the haze value taking into account variation is within the haze range defined by the first and second groups described above, it is considered that the haze value at each position of the base film 55 is also within the haze range defined by the first and second groups described above. For example, when the base film 55 or the dry film resist 50 is provided in a rolled state, if "A+2×B" and "A-2×B" in a sample obtained from a portion of the base film 55 are both within the haze ranges defined by the first and second groups described above, then the haze values at each position of the base film 55 in a rolled state are also considered to be within the haze ranges defined by the first and second groups described above.

The total light transmittance can also be used as an index of transparency of a film such as the base film 55. The total light transmittance of the base film 55 may be, for example, 90% or more, 91% or more, 92% or more, or 93% or more. The total light transmittance of the base film 55 may be, for example, 94% or less, 95% or less, 97% or less, or 99% or less. When the total light transmittance of the base film 55 is 90% or more, the positional accuracy of the exposure can be improved.

The range of the total light transmittance of the base film 55 may be determined by a first group consisting of 90%, 91%, 92% and 93%, and/or a second group consisting of 94%, 95%, 97% and 99%. The range of the total light transmittance of the base film 55 may be determined by a combination of any one of the values included in the first group described above and any one of the values included in the second group described above. The range of the total light transmittance of the base film 55 may be determined by a combination of any two of the values included in the first group described above. The range of the total light transmittance of the base film 55 may be determined by a combination of any two of the values included in the second group described above. For example, it may be 90% or more and 99% or less, 90% or more and 97% or less, 90% or more and 95% or less, 90% or more and 94% or less, 90% or more and 93% or less, 90% or more and 92% or less, 90% or more and 91% or less, 91% or more and 99% or less, 91% or more and 97% or less, 91% or more and 95% or less, 91% or more and 94% or less, 91% or more and 93% or less, 91% or more and 92% or less, or 92% or more and 99% or less. Alternatively, it may be 92% or more and 97% or less, 92% or more and 95% or less, 92% or more and 94% or less, 92% or more and 93% or less, 93% or more and 99% or less, 93% or more and 97% or less, 93% or more and 95% or less, 93% or more and 94% or less, 94% or more and 99% or less, 94% or more and 97% or less, 94% or more and 95% or less, 95% or more and 99% or less, 95% or more and 97% or less, or 97% or more and 99% or less.

The method for measuring the total light transmittance of the base film 55 will be described. First, as in the case of haze measurement, a base film 55 having a length of 700 mm is prepared. Next, the base film 55 is divided into three equal parts in the width direction to create three films. Next, three samples having a width of 50 mm and a length of 100 mm are prepared by cutting a part of each film. Each sample includes the center of each film in the longitudinal direction. Next, the samples are placed in a haze meter so that the first surface 551 is located on the light source side, and the total light transmittance is measured by a method conforming to JIS K7361-1:1997. As the haze meter, a haze meter HM-150 manufactured by Murakami Color Research Laboratory Co., Ltd. is used.

As with haze measurements, total light transmittance is measured at three different locations for each sample. Therefore, when three samples are used, total light transmittance measurements are obtained at nine different locations. The average value C of the measurement results at the nine locations is used as the total light transmittance of the base film 55.

The standard deviation D of the total light transmittance measured at nine locations may be calculated. It is preferable that the total light transmittance value taking into account the variation, calculated from the average total light transmittance value C and the standard deviation D, is within the range of total light transmittance determined by the first and second groups described above. For example, as in the case of the haze value, it is preferable that both "C+2×D" and "C-2×D" are within the range of total light transmittance determined by the first and second groups described above.

One method for increasing the transparency of the base film 55 is to increase the flatness of the surface of the base film 55. On the other hand, if the flatness of the surface of the base film 55 is increased, blocking is more likely to occur when the base film 55 before the resist layer 51 is laminated thereon is stored or transported in a rolled-up state.

Blocking will be described with reference to Figures 3 and 4. Figure 3 is a side view showing an example of the base film 55 in a wound state. Figure 4 is a cross-sectional view showing an enlarged portion of the base film 55 in a wound state. In the wound state of the base film 55, a first surface 551 of a portion of the base film 55 is in contact with a second surface 552 of the other portion of the base film 55 that overlaps the portion. Blocking is a phenomenon in which the first surface 551 of a portion of the base film 55 in a wound state sticks to the second surface 552 of the other portion of the base film 55 that overlaps the portion.

One example of a method for preventing blocking in a film such as the base film 55 is to incorporate particles into the film and form protrusions on the surface of the film. However, if the density of particles in the base film 55 is high, the positional accuracy of the exposure may decrease due to the light passing through the base film 55 being scattered by the particles. In addition, if the portion of the base film 55 that contacts the base layer 56 contains particles, it is possible that depressions due to the particles will be formed in the resist layer 51 laminated on the base film 55.

In order to suppress blocking while ensuring the transparency of the base film 55, this embodiment proposes that the base film 55 has a base layer 56 and a surface layer 57, as shown in Figures 1 and 2. Figure 2 is an enlarged cross-sectional view showing an example of the base film 55 of the dry film resist 50 in Figure 1.

The base layer 56 is a layer containing plastic. The surface layer 57 is located on the base layer 56 and constitutes the first surface 551 of the base film 55. The thickness of the base layer 56 is greater than the thickness of the surface layer 57. By increasing the transparency of the base layer 56, the transparency of the base film 55 can be increased. Furthermore, by providing the surface layer 57 on the base layer 56, the occurrence of blocking can be suppressed. The base layer 56 and the surface layer 57 are described in detail below.

The base layer 56 may include a transparent plastic, such as polyester. Polyester may be made from dicarboxylic acids, such as terephthalic acid, isophthalic acid, and 2,6-naphthalenedicarboxylic acid, and diols, such as ethylene glycol, 1,3-propanediol, and 1,4-butanediol. An example of polyester is polyethylene terephthalate (hereinafter also referred to as PET). Polyethylene terephthalate may be made from terephthalic acid and ethylene glycol.

It is preferable that the base layer 56 does not contain particles made of silica or the like. Even if the base layer 56 contains particles, it is preferable that the density of the particles in the base layer 56 is limited so that the haze of the base film 55 falls within the range of hazes defined by the first and second groups described above.

The thickness of the base layer 56 may be, for example, 8 μm or more, 10 μm or more, 12 μm or more, or 14 μm or more. The thickness of the base layer 56 may be, for example, 16 μm or less, 18 μm or less, 20 μm or less, or 24 μm or less.

The thickness range of the base layer 56 may be determined by a first group consisting of 8 μm, 10 μm, 12 μm, and 14 μm, and/or a second group consisting of 16 μm, 18 μm, 20 μm, and 24 μm. The thickness range of the base layer 56 may be determined by a combination of any one of the values included in the first group described above and any one of the values included in the second group described above. The thickness range of the base layer 56 may be determined by a combination of any two of the values included in the first group described above. The thickness range of the base layer 56 may be determined by a combination of any two of the values included in the second group described above. For example, it may be 8 μm or more and 24 μm or less, 8 μm or more and 20 μm or less, 8 μm or more and 18 μm or less, 8 μm or more and 16 μm or less, 8 μm or more and 14 μm or less, 8 μm or more and 12 μm or less, 8 μm or more and 10 μm or less, 10 μm or more and 24 μm or less, 10 μm or more and 20 μm or less, 10 μm or more and 18 μm or less, 10 μm or more and 16 μm or less, 10 μm or more and 14 μm or less, 10 μm or more and 12 μm or less, 12 μm or more and 24 μm or less, or 1 It may be 2 μm or more and 20 μm or less, 12 μm or more and 18 μm or less, 12 μm or more and 16 μm or less, 12 μm or more and 14 μm or less, 14 μm or more and 24 μm or less, 14 μm or more and 20 μm or less, 14 μm or more and 18 μm or less, 14 μm or more and 16 μm or less, 16 μm or more and 24 μm or less, 16 μm or more and 20 μm or less, 16 μm or more and 18 μm or less, 18 μm or more and 24 μm or less, 18 μm or more and 20 μm or less, or 20 μm or more and 24 μm or less.

The thickness of the base layer 56 may be calculated from an image of a cross section of a laminate including the base layer 56. The laminate including the base layer 56 is a dry film resist 50 or a base film 55. A scanning electron microscope JSM7800FPRIME manufactured by JEOL Ltd. can be used as a device for acquiring an image of the laminate.

The base layer 56 may be a uniaxially stretched film stretched in one direction, or a biaxially stretched film stretched in two directions. The stretching direction of the base layer 56 is not particularly limited. For example, the base layer 56 may be stretched along the length direction of the base film 55, or may be stretched in the width direction perpendicular to the length direction. The thickness of the base layer 56 may be obtained by measuring the thickness of the film constituting the base layer 56. A micrometer MDH-25MB manufactured by Mitutoyo Corporation can be used as a device for measuring the thickness of the film.

The surface layer 57 may contain a binder 571 and particles 572, as shown in FIG. 2. In a portion of the first surface 551 of the base film 55, the particles 572 are exposed from the binder 571, or the binder 571 is raised, thereby forming concaves and convexes on the first surface 551. This allows the first surface 551 to be given a roughness sufficient to suppress blocking.

The arithmetic mean roughness Ra of the first surface 551 formed by the surface layer 57 may be, for example, 0.01 nm or more, 0.02 nm or more, 0.03 nm or more, or 0.05 nm or more. The arithmetic mean roughness Ra may be, for example, 0.07 nm or less, 0.10 nm or less, 0.15 nm or less, or 0.20 nm or less. By having the arithmetic mean roughness Ra of the first surface 551 be 0.01 nm or more, blocking can be suppressed. Furthermore, by having the arithmetic mean roughness Ra of the first surface 551 be 0.20 nm or less, scattering of light that has reached the first surface 551 of the base film 55 can be suppressed. Furthermore, the formation of a gap between the exposure mask used in the exposure process and the first surface 551 can be suppressed.

The range of the arithmetic mean roughness Ra of the first surface 551 formed by the surface layer 57 may be determined by a first group consisting of 0.01 nm, 0.02 nm, 0.03 nm, and 0.05 nm, and/or a second group consisting of 0.07 nm, 0.10 nm, 0.15 nm, and 0.20 nm. The range of the arithmetic mean roughness Ra may be determined by a combination of any one of the values included in the first group described above and any one of the values included in the second group described above. The range of the arithmetic mean roughness Ra may be determined by a combination of any two of the values included in the first group described above. The range of the arithmetic mean roughness Ra may be determined by a combination of any two of the values included in the second group described above. For example, it may be 0.01 nm or more and 0.20 nm or less, 0.01 nm or more and 0.15 nm or less, 0.01 nm or more and 0.10 nm or less, 0.01 nm or more and 0.07 nm or less, 0.01 nm or more and 0.05 nm or less, 0.01 nm or more and 0.03 nm or less, 0.01 nm or more and 0.02 nm or less, 0.02 nm or more and 0.20 nm or less, 0.02 nm or more and 0.15 nm or less, 0.02 nm or more and 0.10 nm or less, 0.02 nm or more and 0.07 nm or less, 0.02 nm or more and 0.05 nm or less, 0.02 nm or more and 0.03 nm or less, or 0.03 nm or more and 0.20 nm or less. Alternatively, it may be 0.03 nm or more and 0.15 nm or less, 0.03 nm or more and 0.10 nm or less, 0.03 nm or more and 0.07 nm or less, 0.03 nm or more and 0.05 nm or less, 0.05 nm or more and 0.20 nm or less, 0.05 nm or more and 0.15 nm or less, 0.05 nm or more and 0.10 nm or less, 0.05 nm or more and 0.07 nm or less, 0.07 nm or more and 0.15 nm or less, 0.07 nm or more and 0.10 nm or less, 0.10 nm or more and 0.20 nm or less, 0.10 nm or more and 0.15 nm or less, or 0.15 nm or more and 0.20 nm or less.

A method for measuring the arithmetic mean roughness Ra of the first surface 551 of the base film 55 will be described. First, a part of the base film 55 is cut to prepare a square sample. The length of a side of the sample is 50 mm. Next, the arithmetic mean roughness Ra of the first surface 551 is measured using a laser microscope VK-X1000 manufactured by Keyence Corporation.
For one sample, the arithmetic mean roughness is measured at nine different points. The average value E of the measurement results at the nine points is used as the arithmetic mean roughness Ra of the first surface 551 of the base film 55.
The standard deviation F of the arithmetic mean roughness measured at nine locations may be calculated. It is preferable that the value of the arithmetic mean roughness Ra, which takes into account the variation and is calculated from the average value E of the arithmetic mean roughness and the standard deviation F, is within the range of the arithmetic mean roughness Ra defined by the above-mentioned first and second groups. For example, as in the case of the haze value, it is preferable that both "E+2×F" and "E−2×F" are within the range of the arithmetic mean roughness Ra defined by the above-mentioned first and second groups.

The binder 571 and particles 572 of the surface layer 57 will be described in detail.

The binder 571 is different from the plastic of the base layer 56. The binder 571 may contain a resin such as polyurethane resin, polyester resin, acrylic resin, or polyimide resin, and may contain, for example, an acrylic urethane resin. The polyurethane resin is a hardened material produced by reacting a polyol as a base material with an isocyanate compound as a hardener. The acrylic urethane resin is a hardened material produced by reacting an acrylic polyol as a base material with an isocyanate compound as a hardener.

The particles 572 may contain an inorganic substance such as silica, and may contain, for example, colloidal silica. The average particle diameter of the particles 572 may be, for example, 5 nm or more, 10 nm or more, 20 nm or more, or 30 nm or more. The average particle diameter of the particles 572 may be, for example, 40 nm or less, 50 nm or less, 70 nm or less, or 100 nm or less. By having the average particle diameter of the particles 572 be 100 nm or less, it is possible to suppress scattering of light that reaches the first surface 551 of the base film 55.

The range of the average particle size of the particles 572 may be determined by a first group consisting of 5 nm, 10 nm, 20 nm, and 30 nm, and/or a second group consisting of 40 nm, 50 nm, 70 nm, and 100 nm. The range of the average particle size of the particles 572 may be determined by a combination of any one of the values included in the first group described above and any one of the values included in the second group described above. The range of the average particle size of the particles 572 may be determined by a combination of any two of the values included in the first group described above. The range of the average particle size of the particles 572 may be determined by a combination of any two of the values included in the second group described above. For example, it may be 5 nm or more and 100 nm or less, 5 nm or more and 70 nm or less, 5 nm or more and 50 nm or less, 5 nm or more and 40 nm or less, 5 nm or more and 30 nm or less, 5 nm or more and 20 nm or less, 5 nm or more and 10 nm or less, 10 nm or more and 100 nm or less, 10 nm or more and 70 nm or less, 10 nm or more and 50 nm or less, 10 nm or more and 40 nm or less, 10 nm or more and 30 nm or less, 10 nm or more and 20 nm or less, 20 nm or more and 100 nm or less, or 20 It may be 20 nm or more and 70 nm or less, 20 nm or more and 50 nm or less, 20 nm or more and 40 nm or less, 20 nm or more and 30 nm or less, 30 nm or more and 100 nm or less, 30 nm or more and 70 nm or less, 30 nm or more and 50 nm or less, 30 nm or more and 40 nm or less, 40 nm or more and 100 nm or less, 40 nm or more and 70 nm or less, 40 nm or more and 50 nm or less, 50 nm or more and 100 nm or less, 50 nm or more and 70 nm or less, or 70 nm or more and 100 nm or less.

The average particle diameter of the particles 572 is calculated from an image of the cross section of the dry film resist 50 or the base film 55. Specifically, first, the area S of each of the 100 particles 572 shown in the image is calculated. Then, assuming that the shape of the particles 572 in the image is a perfect circle, the diameter d of the particles 572 is calculated from the area S. d = 2 x (S / π) ^0.5 . Then, the average value of the diameters d of the 100 particles 572 is calculated, and this is adopted as the average particle diameter of the particles 572. As a device for acquiring the image, a scanning electron microscope JSM7800FPRIME manufactured by JEOL Ltd. can be used.

The thickness of the surface layer 57 may be, for example, 0.05 μm or more, 0.1 μm or more, 0.2 μm or more, or 0.3 μm or more. The thickness of the surface layer 57 may be, for example, 0.4 μm or less, 0.6 μm or less, 0.8 μm or less, or 1.0 μm or less.

The thickness range of the surface layer 57 may be determined by a first group consisting of 0.05 μm, 0.1 μm, 0.2 μm, and 0.3 μm, and/or a second group consisting of 0.4 μm, 0.6 μm, 0.8 μm, and 1.0 μm. The thickness range of the surface layer 57 may be determined by a combination of any one of the values included in the first group described above and any one of the values included in the second group described above. The thickness range of the surface layer 57 may be determined by a combination of any two of the values included in the first group described above. The thickness range of the surface layer 57 may be determined by a combination of any two of the values included in the second group described above. For example, it may be 0.05 μm or more and 1.0 μm or less, 0.05 μm or more and 0.8 μm or less, 0.05 μm or more and 0.6 μm or less, 0.05 μm or more and 0.4 μm or less, 0.05 μm or more and 0.3 μm or less, 0.05 μm or more and 0.2 μm or less, 0.05 μm or more and 0.1 μm or less, 0.1 μm or more and 1.0 μm or less, 0.1 μm or more and 0.8 μm or less, 0.1 μm or more and 0.6 μm or less, 0.1 μm or more and 0.4 μm or less, 0.1 μm or more and 0.3 μm or less, 0.1 μm or more and 0.2 μm or less, or 0.2 μm or more and 1.0 μm or less. It may be 0.2 μm or more and 0.8 μm or less, 0.2 μm or more and 0.6 μm or less, 0.2 μm or more and 0.4 μm or less, 0.2 μm or more and 0.3 μm or less, 0.3 μm or more and 1.0 μm or less, 0.3 μm or more and 0.8 μm or less, 0.3 μm or more and 0.6 μm or less, 0.3 μm or more and 0.4 μm or less, 0.4 μm or more and 1.0 μm or less, 0.4 μm or more and 0.8 μm or less, 0.4 μm or more and 0.6 μm or less, 0.6 μm or more and 1.0 μm or less, 0.6 μm or more and 0.8 μm or less, or 0.8 μm or more and 1.0 μm or less.

The thickness of the surface layer 57, like the thickness of the base layer 56, is calculated from an image of a cross section of the dry film resist 50 or the base film 55. A scanning electron microscope JSM7800FPRIME manufactured by JEOL Ltd. can be used as a device for acquiring the image.

The thickness of the surface layer 57 is smaller than the thickness of the base layer 56. Therefore, the overall thickness of the base film 55 is mainly determined by the thickness of the base layer 56. The thickness of the base film 55 may be, for example, 8 μm or more, 10 μm or more, 12 μm or more, or 14 μm or more. The thickness of the base film 55 may be, for example, 16 μm or less, 18 μm or less, 20 μm or less, or 24 μm or less.

The thickness range of the base film 55 may be determined by a first group consisting of 8 μm, 10 μm, 12 μm, and 14 μm, and/or a second group consisting of 16 μm, 18 μm, 20 μm, and 24 μm. The thickness range of the base film 55 may be determined by a combination of any one of the values included in the first group described above and any one of the values included in the second group described above. The thickness range of the base film 55 may be determined by a combination of any two of the values included in the first group described above. The thickness range of the base film 55 may be determined by a combination of any two of the values included in the second group described above. For example, it may be 8 μm or more and 24 μm or less, 8 μm or more and 20 μm or less, 8 μm or more and 18 μm or less, 8 μm or more and 16 μm or less, 8 μm or more and 14 μm or less, 8 μm or more and 12 μm or less, 8 μm or more and 10 μm or less, 10 μm or more and 24 μm or less, 10 μm or more and 20 μm or less, 10 μm or more and 18 μm or less, 10 μm or more and 16 μm or less, 10 μm or more and 14 μm or less, 10 μm or more and 12 μm or less, 12 μm or more and 24 μm or less, or 1 It may be 2 μm or more and 20 μm or less, 12 μm or more and 18 μm or less, 12 μm or more and 16 μm or less, 12 μm or more and 14 μm or less, 14 μm or more and 24 μm or less, 14 μm or more and 20 μm or less, 14 μm or more and 18 μm or less, 14 μm or more and 16 μm or less, 16 μm or more and 24 μm or less, 16 μm or more and 20 μm or less, 16 μm or more and 18 μm or less, 18 μm or more and 24 μm or less, 18 μm or more and 20 μm or less, or 20 μm or more and 24 μm or less.

When the base film 55 is available separately, the thickness of the base film 55 is measured by a contact type measuring method. For the contact type measuring method, a length gauge "MT1271" made by HEIDENHAIM-METRO, which is equipped with a ball bush guided plunger, is used.

When the base film 55 is obtained in the form of a dry film resist 50 in which a resist layer 51 is laminated on the base film 55, the thickness of the base film 55 is calculated from an image of a cross section of the dry film resist 50. A scanning electron microscope JSM7800FPRIME manufactured by JEOL Ltd. can be used as a device for acquiring the image.

The base film 55 is also simply referred to as a film. In this case, the base film 55 may be expressed as follows.
"First surface 551,
A film having a second surface 552 opposite to the first surface 551 and having an arithmetic mean roughness of the surface of 0.01 nm or more and 0.2 nm or less.

Next, the resist layer 51 will be described. The resist layer 51 contains a material having photosensitivity. For example, the resist layer 51 may contain an acrylic resin and an initiator.

The thickness of the resist layer 51 may be, for example, 3 μm or more, 5 μm or more, 7 μm or more, or 9 μm or more. Also, the thickness of the resist layer 51 may be, for example, 11 μm or less, 13 μm or less, 15 μm or less, or 20 μm or less.

The thickness range of the resist layer 51 may be determined by a first group consisting of 3 μm, 5 μm, 7 μm, and 9 μm, and/or a second group consisting of 11 μm, 13 μm, 15 μm, and 20 μm. The thickness range of the resist layer 51 may be determined by a combination of any one of the values included in the first group described above and any one of the values included in the second group described above. The thickness range of the resist layer 51 may be determined by a combination of any two of the values included in the first group described above. The thickness range of the resist layer 51 may be determined by a combination of any two of the values included in the second group described above. For example, it may be 3 μm or more and 20 μm or less, 3 μm or more and 15 μm or less, 3 μm or more and 13 μm or less, 3 μm or more and 11 μm or less, 3 μm or more and 9 μm or less, 3 μm or more and 7 μm or less, 3 μm or more and 5 μm or less, 5 μm or more and 20 μm or less, 5 μm or more and 15 μm or less, 5 μm or more and 13 μm or less, 5 μm or more and 11 μm or less, 5 μm or more and 9 μm or less, 5 μm or more and 7 μm or less, 7 μm or more and 20 μm or less, 7 μm or more and 7 μm or less. It may be 15 μm or less, 7 μm or more and 13 μm or less, 7 μm or more and 11 μm or less, 7 μm or more and 9 μm or less, 9 μm or more and 20 μm or less, 9 μm or more and 15 μm or less, 9 μm or more and 13 μm or less, 9 μm or more and 11 μm or less, 11 μm or more and 20 μm or less, 11 μm or more and 15 μm or less, 11 μm or more and 13 μm or less, 13 μm or more and 20 μm or less, 13 μm or more and 15 μm or less, or 15 μm or more and 20 μm or less.

The thickness of the resist layer 51 is calculated from an image of the cross section of the dry film resist 50. A scanning electron microscope JSM7800FPRIME manufactured by JEOL Ltd. can be used as a device for acquiring the image.

The base film 55 is also referred to as a first layer. The resist layer 51 is also referred to as a second layer. In this case, the dry film resist 50 may be expressed as follows.
"A first layer 55 having a first surface 551 and a second surface 552 located on the opposite side to the first surface 551 and having an arithmetic mean roughness of the surface of 0.01 nm or more and 0.2 nm or less;
a second layer 51 on the first surface 551, the second layer 51 including a resist; and

Next, the protective film 52 will be described. The protective film 52 is a film that protects the resist layer 51. The protective film 52 may be in contact with the resist layer 51 via an adhesive layer or the like.

The protective film 52 is preferably configured to suppress the occurrence of blocking in the dry film resist 50. Blocking in the dry film resist 50 will be described with reference to FIG. 5 and FIG. 6. FIG. 5 is a side view showing an example of the dry film resist 50 in a wound state. FIG. 6 is a cross-sectional view showing an enlarged portion of the dry film resist 50 in a wound state. In the dry film resist 50 in a wound state, a first surface 501 of a portion of the dry film resist 50 contacts a second surface 502 of the other portion of the base film 55 overlapping the portion. In this embodiment, the surface layer 57 constitutes the first surface 501, and the protective film 52 constitutes the second surface 502. Therefore, in the dry film resist 50 in a wound state, the surface layer 57 and the protective film 52 contact each other.

The static friction coefficient of the protective film 52 is preferably low enough to prevent scratches from occurring on the surface layer 57. The static friction coefficient of the protective film 52 may be, for example, 0.15 or more, 0.18 or more, 0.20 or more, or 0.22 or more. The static friction coefficient of the protective film 52 may be, for example, 0.24 or less, 0.26 or less, 0.28 or less, or 0.30 or less. When the static friction coefficient of the protective film 52 is 0.30 or less, scratches can be prevented from occurring on the surface layer 57 of the dry film resist 50 in a rolled-up state.
If scratches are present on the surface layer 57, light is scattered by the surface layer 57 during the exposure process, which makes exposure defects more likely to occur. The exposure defects are, for example, insufficient reactions caused by irradiation of light in the resist layer 51. The exposure defects may result in reduced accuracy of the positions and shapes of the through holes in the deposition mask.
When the static friction coefficient of the protective film 52 is 0.30 or less, it is possible to suppress the occurrence of scratches on the surface layer 57. This makes it easier to improve the accuracy of the positions and shapes of the through holes of the deposition mask.

The range of the static friction coefficient of the protective film 52 may be determined by a first group consisting of 0.15, 0.18, 0.20, and 0.22, and/or a second group consisting of 0.24, 0.26, 0.28, and 0.30. The range of the static friction coefficient of the protective film 52 may be determined by a combination of any one of the values included in the first group described above and any one of the values included in the second group described above. The range of the static friction coefficient of the protective film 52 may be determined by a combination of any two of the values included in the first group described above. The range of the static friction coefficient of the protective film 52 may be determined by a combination of any two of the values included in the second group described above. For example, it may be 0.15 or more and 0.30 or less, 0.15 or more and 0.28 or less, 0.15 or more and 0.26 or less, 0.15 or more and 0.24 or less, 0.15 or more and 0.22 or less, 0.15 or more and 0.20 or less, 0.15 or more and 0.18 or less, 0.18 or more and 0.30 or less, 0.18 or more and 0.28 or less, 0.18 or more and 0.26 or less, 0.18 or more and 0.24 or less, 0.18 or more and 0.22 or less, 0.18 or more and 0.20 or less, or 0.20 or more and 0.30 or less. Alternatively, it may be 0.20 or more and 0.28 or less, 0.20 or more and 0.26 or less, 0.20 or more and 0.24 or less, 0.20 or more and 0.22 or less, 0.22 or more and 0.30 or less, 0.22 or more and 0.28 or less, 0.22 or more and 0.26 or less, 0.22 or more and 0.24 or less, 0.24 or more and 0.30 or less, 0.24 or more and 0.28 or less, 0.24 or more and 0.26 or less, 0.26 or more and 0.30 or less, 0.26 or more and 0.28 or less, or 0.28 or more and 0.30 or less.

The method for measuring the static friction coefficient of the protective film 52 will be described. First, a dry film resist 50 having a length of 700 mm is prepared. Next, five films are created by dividing the dry film resist 50 into five equal parts in the width direction. Next, five square samples are created by cutting a part of each film. The length of a side of the sample is 63.5 mm. Each sample includes the center of each film in the longitudinal direction. Next, the sample is placed on a horizontal table with the second surface 502 of the sample, which is composed of the protective film 52, facing up. Next, a portable friction meter is placed on the second surface 502 of the sample so that the slider of the portable friction meter is in contact with the second surface 502 of the sample. By starting the measurement in this state, the static friction coefficient of the protective film 52 can be measured.

The portable friction meter used is a HEIDON Tribogear Muse TPYE:94i manufactured by Shinto Scientific Co., Ltd. Details of the friction meter and measurement conditions are as follows.
- Shape of the slider in plan view: circle with a diameter of 25 mm - Weight of the slider: 40 g
Slider material: chrome-plated brass Ambient environment: temperature 23°C, relative humidity 50%

The static friction coefficient is measured for five samples. The average value G of the static friction coefficients measured for each sample is calculated. This average value E is used as the static friction coefficient of the protective film 52.

The standard deviation H of the static friction coefficients measured for each sample may be calculated. It is preferable that the value of the static friction coefficient taking into account the variation, calculated from the average value G of the static friction coefficients and the standard deviation H, is within the range of the static friction coefficients defined by the first and second groups described above. For example, it is preferable that both "G+2×H" and "G-2×H" are within the range of the static friction coefficients defined by the first and second groups described above.

The protective film 52 may include a polymer such as a polyolefin, for example polyethylene. The protective film 52 may be a film made by forming a polymer, for example by extrusion.

The thickness of the protective film 52 may be, for example, 20 μm or more, 25 μm or more, 30 μm or more, or 35 μm or more. The thickness of the protective film 52 may be, for example, 40 μm or less, 50 μm or less, 60 μm or less, or 70 μm or less.

The thickness range of the protective film 52 may be determined by a first group consisting of 20 μm, 25 μm, 30 μm, and 35 μm, and/or a second group consisting of 40 μm, 50 μm, 60 μm, and 70 μm. The thickness range of the protective film 52 may be determined by a combination of any one of the values included in the above-mentioned first group and any one of the values included in the above-mentioned second group. The thickness range of the protective film 52 may be determined by a combination of any two of the values included in the above-mentioned first group. The thickness range of the protective film 52 may be determined by a combination of any two of the values included in the above-mentioned second group. For example, it may be 20 μm or more and 70 μm or less, 20 μm or more and 60 μm or less, 20 μm or more and 50 μm or less, 20 μm or more and 40 μm or less, 20 μm or more and 35 μm or less, 20 μm or more and 30 μm or less, 20 μm or more and 25 μm or less, 25 μm or more and 70 μm or less, 25 μm or more and 60 μm or less, 25 μm or more and 50 μm or less, 25 μm or more and 40 μm or less, 25 μm or more and 35 μm or less, 25 μm or more and 30 μm or less, or 30 μm or more and 70 μm or less. Alternatively, it may be 30 μm or more and 60 μm or less, 30 μm or more and 50 μm or less, 30 μm or more and 40 μm or less, 30 μm or more and 35 μm or less, 35 μm or more and 70 μm or less, 35 μm or more and 60 μm or less, 35 μm or more and 50 μm or less, 35 μm or more and 40 μm or less, 40 μm or more and 70 μm or less, 40 μm or more and 60 μm or less, 40 μm or more and 50 μm or less, 50 μm or more and 70 μm or less, 50 μm or more and 60 μm or less, or 60 μm or more and 70 μm or less.

When the protective film 52 is available separately, the thickness of the protective film 52 is measured by a contact measurement method. For the contact measurement method, a length gauge "MT1271" made by HEIDENHAIM-METRO, which is equipped with a ball bush guided plunger, is used.

When the protective film 52 is obtained in the form of a laminated dry film resist 50 laminated on the resist layer 51, the thickness of the protective film 52 is calculated from an image of a cross section of the dry film resist 50. A scanning electron microscope JSM7800FPRIME manufactured by JEOL Ltd. can be used as a device for acquiring the image.

It is preferable that the protective film 52 does not contain particles made of inorganic substances, etc. This makes it possible to prevent depressions caused by particles in the protective film 52 from being formed in the resist layer 51.

Next, an example of a method for producing the dry film resist 50 will be described.

First, a film for forming the base layer 56 is prepared. Next, a liquid containing the binder 571 and the particles 572 is prepared, and the liquid is applied onto the film. This makes it possible to obtain the base film 55 having the base layer 56 and the surface layer 57.

The film for forming the base layer 56 may be uniaxially or biaxially stretched. The process of stretching the film may be performed before or after applying the liquid containing the binder 571 and the particles 572 to the film.

Next, a liquid containing a photosensitive material is prepared and applied onto the base layer 56. This makes it possible to obtain a laminate comprising the base film 55 and the resist layer 51.

Next, the protective film 52 is attached to the resist layer 51. This results in a laminate comprising the base film 55, the resist layer 51, and the protective film 52, as shown in FIG. 1.

Next, we will explain how to use the dry film resist 50. Here, we will explain an example of manufacturing a deposition mask by etching a metal plate using the dry film resist 50.

First, the metal plate 21 is prepared. The metal plate 21 may contain an iron alloy. As the iron alloy, an iron alloy containing nickel may be used. The iron alloy may contain cobalt in addition to nickel. For example, as the material of the metal plate 21, an iron alloy in which the total content of nickel and cobalt is 28 mass% or more and 54 mass% or less and the cobalt content is 0 mass% or more and 6 mass% or less may be used.
The total content of nickel and cobalt in the metal plate 21 may be 28% by mass or more and 38% by mass or less. In this case, specific examples of the iron alloy containing nickel or nickel and cobalt include Invar, Super Invar, and Ultra Invar. The Invar is an iron alloy containing 34% by mass or more and 38% by mass or less of nickel, the balance being iron and unavoidable impurities. The Super Invar is an iron alloy containing 30% by mass or more and 34% by mass or less of nickel, cobalt, and the balance being iron and unavoidable impurities. The Ultra Invar is an iron alloy containing 28% by mass or more and 34% by mass or less of nickel, 2% by mass or more and 7% by mass or less of cobalt, 0.1% by mass or more and 1.0% by mass or less of manganese, 0.10% by mass or less of silicon, 0.01% by mass or less of carbon, and the balance being iron and unavoidable impurities.
The total content of nickel and cobalt in the metal plate 21 may be 38% by mass or more and 54% by mass or less. In this case, a specific example of the iron alloy containing nickel or nickel and cobalt is a low-thermal expansion Fe-Ni-based plated alloy. The low-thermal expansion Fe-Ni-based plated alloy is an iron alloy containing 38% by mass or more and 54% by mass or less of nickel, with the balance being iron and unavoidable impurities.

The thickness of the metal plate 21 may be, for example, 5 μm or more, 7 μm or more, 10 μm or more, or 13 μm or more. The thickness of the metal plate 21 may be, for example, 16 μm or less, 20 μm or less, 25 μm or less, or 30 μm or less. By reducing the thickness of the metal plate 21, it becomes easier to improve the accuracy of the position and shape of the through holes formed in the metal plate 21. It also becomes easier to improve the accuracy of the position and shape of the deposition material attached to the target substrate in the deposition process using the metal plate 21 and a deposition mask having through holes.

The thickness range of the metal plate 21 may be determined by a first group consisting of 5 μm, 7 μm, 10 μm, and 13 μm, and/or a second group consisting of 16 μm, 20 μm, 25 μm, and 30 μm. The thickness range of the metal plate 21 may be determined by a combination of any one of the values included in the first group described above and any one of the values included in the second group described above. The thickness range of the metal plate 21 may be determined by a combination of any two of the values included in the first group described above. The thickness range of the metal plate 21 may be determined by a combination of any two of the values included in the second group described above. For example, it may be 5 μm or more and 30 μm or less, 5 μm or more and 25 μm or less, 5 μm or more and 20 μm or less, 5 μm or more and 16 μm or less, 5 μm or more and 13 μm or less, 5 μm or more and 10 μm or less, 5 μm or more and 7 μm or less, 7 μm or more and 30 μm or less, 7 μm or more and 25 μm or less, 7 μm or more and 20 μm or less, 7 μm or more and 16 μm or less, 7 μm or more and 13 μm or less, 7 μm or more and 10 μm or less, 10 μm or more and 30 μm or less, or 10 μm or less. It may be 25 μm or less, 10 μm or more and 20 μm or less, 10 μm or more and 16 μm or less, 10 μm or more and 13 μm or less, 13 μm or more and 30 μm or less, 13 μm or more and 25 μm or less, 13 μm or more and 20 μm or less, 13 μm or more and 16 μm or less, 16 μm or more and 30 μm or less, 16 μm or more and 25 μm or less, 16 μm or more and 20 μm or less, 20 μm or more and 30 μm or less, 20 μm or more and 25 μm or less, or 25 μm or more and 30 μm or less.

A contact-type measuring method is used to measure the thickness of the metal plate 21. For the contact-type measuring method, a length gauge "MT1271" by HEIDENHAIM-METRO, equipped with a ball bush guide type plunger, manufactured by HEIDENHAIN, is used.

The metal plate 21 may be produced by rolling an iron alloy. The metal plate obtained by rolling may be etched over the entire surface to produce the metal plate 21 to which the dry film resist 50 is attached. The metal plate 21 may also be produced by a plating process. For example, the metal plate 21 may be produced by forming a plating film on the surface of a rotating drum made of stainless steel or the like that is partially immersed in a plating solution, and then peeling off the plating film.

Next, the protective film 52 is peeled off from the dry film resist 50, and then the resist layer 51 of the dry film resist 50 is attached to the metal plate 21, as shown in FIG. 7.

Next, an exposure mask 70 including a light-transmitting region 71 and a light-shielding region 72 is prepared, and as shown in FIG. 8, the exposure mask 70 is placed on the surface layer 57 of the dry film resist 50. At this time, it is preferable that the exposure mask 70 is in contact with the surface layer 57. The light-shielding region 72 includes a material having light-shielding properties, such as chromium.

Next, as shown in FIG. 8, an exposure process is performed in which light L1 is irradiated onto the dry film resist 50 through the light-transmitting region 71 of the exposure mask 70. The light incident on the dry film resist 50 passes through the base film 55 and reaches the resist layer 51. This exposes the resist layer 51.

The wavelength of light L1 in the exposure process is appropriately selected according to the characteristics of the resist layer 51. Light L1 may be visible light. The wavelength of light L1 may be, for example, 380 nm or more, 430 nm or more, 480 nm or more, or 530 nm or more. In addition, the wavelength of light L1 may be, for example, 580 nm or less, 630 nm or less, 700 nm or less, or 780 nm or less.

The range of wavelengths of light L1 may be determined by a first group consisting of 380 nm, 430 nm, 480 nm, and 530 nm, and/or a second group consisting of 580 nm, 630 nm, 700 nm, and 780 nm. The range of wavelengths of light L1 may be determined by a combination of any one of the values included in the first group described above and any one of the values included in the second group described above. The range of wavelengths of light L1 may be determined by a combination of any two of the values included in the first group described above. The range of wavelengths of light L1 may be determined by a combination of any two of the values included in the second group described above. For example, it may be 380 nm or more and 780 nm or less, 380 nm or more and 700 nm or less, 380 nm or more and 630 nm or less, 380 nm or more and 580 nm or less, 380 nm or more and 530 nm or less, 380 nm or more and 480 nm or less, 380 nm or more and 430 nm or less, 430 nm or more and 780 nm or less, 430 nm or more and 700 nm or less, 430 nm or more and 630 nm or less, 430 nm or more and 580 nm or less, 430 nm or more and 530 nm or less, 430 nm or more and 480 nm or less, or 480 nm or more and 780 nm or less. Alternatively, it may be 480 nm or more and 700 nm or less, 480 nm or more and 630 nm or less, 480 nm or more and 580 nm or less, 480 nm or more and 530 nm or less, 530 nm or more and 780 nm or less, 530 nm or more and 700 nm or less, 530 nm or more and 630 nm or less, 530 nm or more and 580 nm or less, 580 nm or more and 780 nm or less, 580 nm or more and 700 nm or less, 580 nm or more and 630 nm or less, 630 nm or more and 780 nm or less, 630 nm or more and 700 nm or less, or 700 nm or more and 780 nm or less.

Figure 9 is a plan view showing an example of an exposure mask 70. The light-shielding regions 72 of the exposure mask 70 may be arranged along two different directions. For example, as shown in Figure 9, the light-shielding regions 72 may be arranged along a first direction D1 and a second direction D2 perpendicular to the first direction D1.

In the etching process described below, through holes are formed in the metal plate 21 in the areas that overlap the light-shielding areas 72 in a plan view. Therefore, when the exposure mask 70 shown in FIG. 9 is used, the through holes formed in the metal plate 21 are also arranged along the first direction D1 and the second direction D2 that is perpendicular to the first direction D1.

The dimensions of the light shielding region 72 may be, for example, 10 μm or more, 15 μm or more, 20 μm or more, or 25 μm or more. Also, the dimensions of the light shielding region 72 may be, for example, 30 μm or less, 35 μm or less, 40 μm or less, or 50 μm or less.

The range of dimensions of the light-shielding region 72 may be defined by a first group consisting of 10 μm, 15 μm, 20 μm, and 25 μm, and/or a second group consisting of 30 μm, 35 μm, 40 μm, and 50 μm. The range of dimensions of the light-shielding region 72 may be defined by a combination of any one of the values included in the first group described above and any one of the values included in the second group described above. The range of dimensions of the light-shielding region 72 may be defined by a combination of any two of the values included in the first group described above. The range of dimensions of the light-shielding region 72 may be defined by a combination of any two of the values included in the second group described above. For example, it may be 10 μm or more and 50 μm or less, 10 μm or more and 40 μm or less, 10 μm or more and 35 μm or less, 10 μm or more and 30 μm or less, 10 μm or more and 25 μm or less, 10 μm or more and 20 μm or less, 10 μm or more and 15 μm or more and 15 μm or more and 50 μm or less, 15 μm or more and 40 μm or less, 15 μm or more and 35 μm or less, 15 μm or more and 30 μm or less, 15 μm or more and 25 μm or less, 15 μm or more and 20 μm or more and 20 μm or more and 50 μm or less. Alternatively, it may be 20 μm or more and 40 μm or less, 20 μm or more and 35 μm or less, 20 μm or more and 30 μm or less, 20 μm or more and 25 μm or less, 25 μm or more and 50 μm or less, 25 μm or more and 40 μm or less, 25 μm or more and 35 μm or less, 25 μm or more and 30 μm or less, 30 μm or more and 50 μm or less, 30 μm or more and 40 μm or less, 30 μm or more and 35 μm or less, 35 μm or more and 50 μm or less, 35 μm or more and 40 μm or less, or 40 μm or more and 50 μm or less.

The dimension of the light-shielding region 72 is the maximum dimension of the light-shielding region 72 in the direction in which the light-shielding region 72 is arranged. When the light-shielding region 72 is arranged along two different directions as shown in FIG. 9, the dimension of the light-shielding region 72 is the smaller of the maximum dimension S1 of the light-shielding region 72 in the first direction D1 and the maximum dimension S2 of the light-shielding region 72 in the second direction D2.

Next, a development process is carried out to develop the resist layer 51 to form an image on the exposed resist layer 51. This allows the formation of a resist pattern including the resist layer 51 partially located on the surface of the metal plate 21, as shown in FIG. 10.

Next, an etching process is carried out in which the areas of the metal plate 21 that are not covered by the resist layer 51 are etched using an etching solution. As a result, as shown in FIG. 11, through holes 25 can be formed in the areas of the metal plate 21 that are not covered by the resist layer 51. Thereafter, the resist layer 51 remaining on the metal plate 21 is removed. In this manner, the deposition mask 20 can be obtained.

In this embodiment, the base film 55 of the dry film resist 50 has high transparency. For example, the haze of the base film 55 is 1.00% or less. This makes it possible to suppress scattering of the light L1 for exposing the resist layer 51 while passing through the base film 55. This improves the positional accuracy of the exposure, thereby increasing the accuracy of the position and shape of the resist pattern. This makes it possible to form the through holes 25 with small dimensions in the metal plate 21 with high precision.

In addition, in this embodiment, the arithmetic mean roughness Ra of the first surface 551 of the base film 55 of the dry film resist 50 is 0.20 nm or less. Therefore, when the base film 55 is wound up or when the dry film resist 50 including the base film 55 and the resist layer 51 is wound up, it is possible to suppress the occurrence of blocking.

Note that various modifications can be made to the embodiment described above. Below, other embodiments will be described with reference to the drawings as necessary. In the following description and the drawings used in the following description, parts that can be configured similarly to the embodiment described above will be designated by the same reference numerals as those used for the corresponding parts in the embodiment described above, and duplicated descriptions will be omitted. Also, if it is clear that the effects obtained in the embodiment described above can also be obtained in other embodiments, the description may be omitted.

In the above embodiment, an example has been shown in which the resist layer 51 of the dry film resist 50 is attached to one of the two surfaces of the metal plate 21. However, this is not limited to this, and as shown in FIG. 12, the resist layer 51 of the dry film resist 50 may be attached to each of the two surfaces of the metal plate 21.

Figure 13 is a cross-sectional view showing an example of a process for exposing and developing the dry film resist 50 shown in Figure 12. As shown in Figure 13, the dimensions of the resist layer 51 remaining on one side of the metal plate 21 may be different from the dimensions of the resist layer 51 remaining on the other side of the metal plate 21. Figure 14 is a cross-sectional view showing an example of a deposition mask produced by etching the metal plate 21 shown in Figure 13.

In the above embodiment, an example was shown in which the first surface 551 of the base film 55 is configured by the surface layer 57. However, the configuration of the first surface 551 is arbitrary as long as the arithmetic mean roughness Ra of the first surface 551 of the base film 55 can be set to a value within the range determined by the above-mentioned first and second groups. For example, as shown in FIG. 15, the first surface 551 of the base film 55 may be configured by the base layer 56.

Figure 16 is an enlarged cross-sectional view showing an example of the base film 55 of the dry film resist 50 of Figure 15. As shown in Figure 16, the first surface 551 formed by the base layer 56 may have protrusions 561. The size and distribution of the protrusions 561 are adjusted so that the arithmetic mean roughness Ra of the first surface 551 of the base film 55 falls within the ranges defined by the first and second groups described above.

The method for forming the protrusions 561 on the base layer 56 is not particularly limited. For example, the protrusions 561 can be formed by a processing method such as nanoimprinting.

Next, the above-mentioned embodiment will be explained in more detail using examples, but the embodiment is not limited to the description of the following examples as long as it does not exceed the gist of the embodiment.

Example 1
A stretched film for constituting the base layer 56 was produced by the following procedure. First, pellets of PET having an intrinsic viscosity of 0.65 dl/g were prepared. The pellets did not contain inorganic particles such as silica. Next, the pellets were dried by heating them to 180°C. Next, the PET was extruded from a T-die of a single-screw extruder. Next, an unstretched film having a thickness of 300 μm was produced by sandwiching the extruded PET between mirror-finished rolls. The extrusion temperature of the T-die was 300°C. The temperature of the mirror-finished rolls was 15°C. Next, a stretched film was produced by stretching the unstretched film 3.3 times in the machine direction.

Next, a surface layer 57 was formed on the surface of the stretched film by the following procedure. First, a coating liquid containing silica particles, polyethylene emulsion, and melamine was prepared. The average particle size of the silica particles was 30 nm. The acid value of the polyethylene emulsion was 25 mg KOH/g. The weight ratios of the silica particles, polyethylene emulsion, and melamine in the coating liquid were 5 wt%, 70 wt%, and 25 wt%, respectively. Next, the coating liquid was applied to one surface of the stretched film by a bar coating method. Next, the stretched film was stretched 3.1 times in the width direction perpendicular to the flow direction. Next, the stretched film was heated to 230°C to solidify the coating liquid. The thickness of the surface layer 57 composed of the solidified coating liquid was 0.5 μm. Next, both ends of the stretched film in the width direction were cut so that the width of the stretched film was 600 mm. In this way, a base film 55 including a base layer 56 containing a stretched film and a surface layer 57 was produced. The base film 55 has a thickness of 16 μm, a width of 600 mm, and a length of 300 m.

As a first evaluation, the arithmetic mean roughness Ra of the first surface 551 of the base film 55 was measured using a laser microscope VK-X1000 manufactured by Keyence Corporation. The arithmetic mean roughness Ra was 0.15 nm.

For the second and third evaluations, the haze and total light transmittance of the base film 55 were measured using a haze meter HM-150 manufactured by Murakami Color Research Laboratory Co., Ltd. The haze was 0.8%. The total light transmittance was 91%.

The protective film 52 was produced by the following procedure. First, pellets of metallocene polyethylene having a density of 0.905 g/cm ³ and MFR of 3.5 were prepared. Then, the metallocene polyethylene was extruded from the T-die of a single-screw extruder. Then, the extruded metallocene polyethylene was sandwiched between a mirror roll and a shaping roll to produce a film having a thickness of 30 μm. The extrusion temperature of the T-die was 300° C. The temperature of the mirror roll was 5° C. Then, both ends of the film in the width direction were cut so that the width of the film was 610 mm. In this way, a protective film 52 containing metallocene polyethylene was produced. The protective film 52 has a thickness of 30 μm, a width of 610 mm, and a length of 300 m. Then, the protective film 52 was wound up. The surface of the protective film 52 located on the mirror roll side is also referred to as the first protective surface.

The dry film resist 50 was prepared by the following procedure. First, a liquid containing a photosensitive material was applied to the second surface 552 of the base film 55. Next, the liquid was solidified by heating the base film 55. The resist layer 51 formed by the solidified liquid had a thickness of 9 μm and a width of 590 mm. Next, the first protective surface of the protective film 52 was attached to the resist layer 51. In this way, the dry film resist 50 including the base film 55, the resist layer 51, and the protective film 52 was prepared. Next, both ends of the dry film resist 50 in the width direction were cut by 10 mm each. Next, the dry film resist 50 was rolled up.

Then, the dry film resist 50 was unwound. As the fourth evaluation, it was confirmed whether blocking occurred when unwound. No blocking occurred.

As the fifth evaluation, the surface layer 57 of the unwound dry film resist 50 was visually inspected to see if it had any scratches. No scratches were found.

As the sixth evaluation, a deposition mask 20 was produced by etching a metal plate 21 using a dry film resist 50. First, as shown in FIG. 12, a resist layer 51 of the dry film resist 50 was attached to each of the two surfaces of the metal plate 21. Next, the resist layer 51 was exposed to light. Then, the base film 55 was peeled off from the resist layer 51. Then, the resist layer was developed. Through these steps, the resist layer 51 was processed as shown in FIG. 13. Next, the metal plate 21 was etched to form a through hole 25 in the metal plate 21 as shown in FIG. 14. In this way, a deposition mask 20 including a metal plate 21 and a plurality of through holes 25 was produced.

The multiple through holes 25 are aligned in the first direction D1 and the second direction D2. The number of through holes 25 aligned in the first direction D1 is 2353, and the number of through holes 25 aligned in the second direction D2 is 1323. The pitch of the through holes 25 in the first direction D1 is 56 μm, and the pitch of the through holes 25 in the second direction D2 is 56 μm. The shape of the through holes 25 in a plan view is a circle with a diameter of 28 μm.

The area of all the through holes 25 was measured using the light passing through the through holes 25. Specifically, first, the deposition mask 20 and the substrate were prepared. The deposition mask 20 includes a first surface and a second surface. The second surface is the surface located on the deposition source side in the deposition process. In the deposition process, a part of the deposition material that reaches the second surface passes through the through holes 25 and reaches the first surface. The substrate faces the first surface of the deposition mask. Next, the second surface of the deposition mask 20 was irradiated with light along the normal direction of the second surface. At this time, a light irradiation area irradiated by the light that passed through the through holes 25 of the deposition mask 20 is formed on the substrate. The dimensions of this light irradiation area were measured as the dimensions of the through holes 25. Next, the average value I and standard deviation J of the area of the through holes 25 were calculated. Next, it was confirmed whether (3J/I)×100 was 5 or less. (3J/I)×100 was 5 or less.

(Examples 2 to 6 and Comparative Examples 1 and 2)
At least one of the following parameters was changed from that in Example 1 to prepare a base film 55, a protective film 52, and a dry film resist 50.
- Intrinsic viscosity of PET in base layer 56 - Thickness of base layer 56 - Average particle size of silica particles in surface layer 57 - Weight ratio of silica particles in the coating liquid for surface layer 57 - Weight ratio of polyethylene emulsion in the coating liquid for surface layer 57 - Weight ratio of melamine in the coating liquid for surface layer 57 - Thickness of surface layer 57 Each parameter in Examples 2 to 6 and Comparative Examples 1 and 2 is shown in Figure 17.

As in Example 1, the first to third evaluations were performed on the base film 55. The evaluation results are shown in Figure 17.

As in Example 1, the fourth to sixth evaluations were performed on the dry film resist 50. The evaluation results are shown in FIG. 17. In the row of evaluation 4, "good" is shown if no blocking occurred, and "bad" is shown if blocking occurred. In the row of evaluation 5, "good" is shown if no scratches occurred on the surface layer 57, and "bad" is shown if scratches occurred on the surface layer 57. In the row of evaluation 6, "good" is shown if (3J/I)×100 was 5 or less, and "bad" is shown if (3J/I)×100 was more than 5.

As shown in FIG. 17, blocking occurred in Comparative Example 1, in which the arithmetic mean roughness Ra of the base film 55 was 0.005 nm. On the other hand, blocking did not occur in Examples 1 to 6, in which the arithmetic mean roughness Ra of the base film 55 was 0.01 nm or more.

As shown in FIG. 17, in Comparative Example 2, in which the arithmetic mean roughness Ra of the base film 55 was 0.3 nm, (3J/I)×100 exceeded 5. On the other hand, in Examples 1 to 6, in which the arithmetic mean roughness Ra of the base film 55 was 0.2 nm or less, (3J/I)×100 was 5 or less.

(Examples 7 to 12 and Comparative Example 3)
At least one of the following parameters was changed from that in Example 1 to prepare a base film 55, a protective film 52, and a dry film resist 50.
Density of the metallocene polyethylene of the protective film 52 MFR of the metallocene polyethylene of the protective film 52
Thickness of Protective Film 52 The parameters in Examples 7 to 12 and Comparative Example 3 are shown in FIG.

As the seventh evaluation, the static friction coefficient of the protective film 52 was measured. The evaluation results are shown in Figure 18.

As in Example 1, the fifth and sixth evaluations were performed on the dry film resist 50. The evaluation results are shown in Figure 18.

As shown in FIG. 18, in Comparative Example 3, in which the static friction coefficient of the protective film 52 was 0.31, scratches were generated on the surface layer 57. On the other hand, in Examples 7 to 12, in which the static friction coefficient of the protective film 52 was 0.30 or less, no scratches were generated on the surface layer 57.

Claims (16)

A base film used in a dry film resist having a resist layer,
a base layer comprising a plastic;
Particles exposed on a portion of the first surface of the base film;
the first surface is a surface of the base film that is located on an opposite side to the resist layer,
The average particle size of the particles is 5 nm or more and 10 nm or less,
the base film includes a surface layer located on the base layer and constituting the first surface of the base film;
the surface layer includes a binder and the particles,
the particles are exposed from the binder or the binder is raised in a portion of the first surface, thereby forming projections and recesses on the first surface;
A base film, wherein the weight ratio of the particles in the surface layer is 5% by weight or more and 10% by weight or less . The base film according to claim 1, wherein the haze of the base film is 1.0% or less. The base film according to claim 1 or 2, wherein the total light transmittance of the base film is 90% or more. The base film according to any one of claims 1 to 3, wherein the thickness of the base film is 8 μm or more and 24 μm or less. The base film according to any one of claims 1 to 3, wherein the thickness of the base film is 12 μm or more and 16 μm or less. The base film according to claim 1 , wherein the surface layer has a thickness of 1.0 μm or less. The base film according to claim 1 , wherein the particles of the surface layer comprise silica. A base film according to any one of claims 1 to 7 ;
a resist layer on a second surface of the base film opposite the first surface. The dry film resist according to claim 8 , wherein the resist layer has a thickness of 5 μm or more and 15 μm or less. The dry film resist according to claim 8 or 9 , further comprising a protective film for protecting the resist layer. The dry film resist of claim 10 , wherein the protective film comprises polyethylene. The dry film resist according to claim 10 or 11 , wherein the protective film has a thickness of 20 μm or more and 50 μm or less. 13. The dry film resist according to claim 10 , wherein the protective film has a static friction coefficient of 0.30 or less. A step of attaching the resist layer of the dry film resist according to any one of claims 8 to 13 to a metal plate;
and irradiating the resist layer with light through a light-transmitting region of an exposure mask including a light-transmitting region and a light-shielding region. 15. The exposure method according to claim 14 , wherein the light shielding region of the exposure mask has a dimension of 30 [mu]m or less. 16. The exposure method according to claim 14 , wherein the metal plate has a thickness of 30 [mu]m or less.