JP2962457B2 - Diazo photosensitive material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a color-developed image having excellent light-shielding properties, and has excellent adhesion to other materials (original plates and photosensitive materials) during close-contact printing. The present invention relates to a diazo photosensitive material having excellent adhesiveness to a photosensitive resin layer of a laminate provided with a conductive resin layer and excellent transparency.

[0002]

2. Description of the Related Art A transparent diazo photosensitive film in which a diazo photosensitive layer for providing a light-shielding color image is formed on a transparent film is known. Such a film is used as a photomask for making a printed wiring board and for making various printing original plates.

Conventionally, for example, in the production of a printed wiring board, a photomask (pattern) is superimposed on a photosensitive resin layer provided on a conductive layer (copper layer) such as a copper-clad laminate, and the photomask is passed through the photomask. The photosensitive resin layer is exposed with a contact printing machine for a predetermined time. Then, the exposed photosensitive resin layer is developed to form a pattern. Thereafter, unnecessary portions of the conductive layer are removed by etching, and the remaining photosensitive resin layer is further removed to form a printed wiring board having a predetermined wiring pattern. During this operation, the contact baking operation has a profound effect on the resolution of the image and the work efficiency when creating a printed wiring board. This causes the wiring pattern to be interrupted or distorted. Further, in order to improve the degree of adhesion, it is necessary to take a sufficient suction time for vacuuming when air existing between the photomask and the photosensitive resin is removed by suction.

Recently, a transparent diazo photosensitive film which can be used for producing a printed wiring board has been proposed (Japanese Patent Publication No. 4-76461), and a considerable effect has been recognized. Was not satisfactory in terms of the adhesion to the photosensitive resin layer during the printing operation and the resolution thereof. Further, in order to improve the degree of adhesion, it takes a long time to suck and remove the air between the photomask and the photosensitive resin layer, which leaves problems such as poor work efficiency.

[0005]

An object of the present invention is to provide a diazo photosensitive material having the following characteristics. (1) Excellent adhesion to the original film and the photosensitive resin layer on the copper-clad laminate. (2) A photomask obtained from a diazo photosensitive material is overlaid on the photosensitive resin layer of the copper-clad laminate, A short suction time for removing air present between the mask and the photosensitive resin layer by suction. (3) A diazo photosensitive material and a photomask obtained therefrom can be easily distinguished from each other. (4) Non-image area ( (Transparent area) has excellent ultraviolet transmittance. (5) The photosensitive layer is not easily damaged. (6) The photomask obtained from the diazo photosensitive material can be easily retouched.

[0006]

Means for Solving the Problems The present inventors have conducted various studies to solve the above problems, and as a result, have completed the present invention. That is, according to the present invention, the general formula

Embedded image (Wherein R ¹ and R ² represent lower alkyl groups and X represents an anion), phenylphenol, N- (2′-hydroxy lower alkyl) -β-resorcylamide, and a Coulter counter method. Thickness containing solid fine powder having an average particle size of 1.0 to 8.0 μm according to
A photosensitive layer having a thickness of from 0.5 to 14 μm on a transparent support, wherein the content of solid fine powder in the photosensitive layer is 0.5 to 5% by weight, and the center line average roughness of the photosensitive layer surface is 0.05 ~ 0.30
A diazo photosensitive material is provided which has an average light transmittance of 40% or more in a non-image area (transparent area) with respect to all light having a wavelength of 300 to 500 nm.

In the diazo compound (I) used in the present invention, the lower alkyl groups R ¹ and R ² have 1 to 6 carbon atoms.
Alkyl group, for example, a methyl group, an ethyl group, a propyl group, a butyl group and the like. Preferred examples of the anion X include PF ₆ , BF ₄ , and Cl · 1/2 Zncl ₂ .

The phenylphenol and N- (2′-hydroxy lower alkyl) -β-resorcinamide used as couplers for the diazo compound in the present invention are represented by the following structural formula. (Phenylphenol)

Embedded image (N- (2′-hydroxy lower alkyl) -β-resorcylamido)

Embedded image

In the above formula, R ³ OH represents a hydroxy lower alkyl group. Examples of the lower alkyl group R ³ include a methyl group, an ethyl group, a propyl group and a butyl group having 1 to 6 carbon atoms.
Alkyl group.

In the present invention, the proportion of the diazo compound (I), couplers (II) and (III) used is 0.8 mol of the total coupler [(II) + (III)] to 1 mol of the diazo compound.
２．５2.5 mol, preferably 1.2-1.6 mol.
The proportion of coupler (II) used is 80 to 99 mol%, preferably 85 to 95 mol%, and the proportion of coupler (III) is 1 to 20 mol%, preferably 5 to 95 mol%, based on all couplers. １５15 mol%.

The solid fine powder used in the present invention includes fine powders of inorganic substances such as silica, clay, talc, alumina, calcium carbonate and titanium oxide, polyethylene, and the like.
Examples include fine powders of organic substances such as polypropylene, polystyrene, acrylate / styrene copolymer, methacrylate / styrene copolymer, urea resin, melamine resin, guanamine resin, and benzoguanamine resin. The average particle diameter of these solid fine powders is 1 to 8 μm, preferably 2.5 to 6.0 μm, as an average particle diameter by a Coulter counter method.
m.

The diazo photosensitive material of the present invention (hereinafter, also simply referred to as "photosensitive material") is produced by applying and drying a coating solution containing the diazo compound, a coupler and a fine solid powder on a transparent support. You. In addition to the diazo compound, the coupler and the solid fine powder, a binder for binding these components to the support is added to the coating solution. Examples of the binder include polyvinyl alcohol, polyvinyl butyral, and nitro. cellulose,
Various polymer substances such as carboxymethyl cellulose are used. Examples of the solvent used for the coating liquid include conventional solvents such as water, alcohol, methyl ethyl ketone, methyl cellosolve, and dimethylformamide. Further, the coating liquid may contain a conventional auxiliary component, for example, citric acid, tartaric acid, sulfosalicylic acid, p
Thiourea, diphenylthiourea, and the like as antioxidants such as toluenesulfonic acid; and ultraviolet absorbers, dyes, surfactants, and antistatic agents.

As the transparent support, for example, polyester film, polyamide film, polyvinyl chloride film, polypropylene film, tracing paper, cellulose triacetate film and the like are used.
Its thickness is 25-250 μm, preferably 100-2
00 μm. The thickness of the photosensitive layer formed on the transparent support is 4 to 14 μm, preferably 6 to 12 μm. When the thickness of the photosensitive layer exceeds 14 μm, for example, it is difficult to form a high-accuracy image when performing close contact baking when producing a printed wiring board, while the thickness of the photosensitive layer is less than 4 μm. In such a case, it becomes difficult to manufacture a photomask having a high density color image.

In the present invention, the average particle size of the solid fine powder contained in the photosensitive layer is determined to be 1 by a Coulter counter method.
And the content of the solid fine powder in the photosensitive layer is 0.5 to 5% by weight, preferably 1 to 5 μm.
And a center line average roughness of the photosensitive layer surface of 0.05 to 0.3 μm, preferably 0.1 to 4% by weight.
And the average light transmittance of the non-image portion (transparent portion) to all light in the wavelength range of 300 to 500 nm of the photosensitive material is 40% or more, preferably 50% or more. Defined in

In the light-sensitive material of the present invention, if the average particle diameter of the solid fine powder is larger than the above range, the amount of irregular reflection by the solid fine powder in the obtained light-sensitive material increases, making it difficult to obtain a light-sensitive material having good transparency. become. On the other hand, when the average particle size of the solid fine powder is smaller than the above range, the compounding amount of the solid fine powder for obtaining the desired center line average roughness of the photosensitive layer surface is increased, and the transmittance of the obtained photosensitive material is reduced. It becomes impossible to perform close contact printing of a high-resolution image on the photosensitive resin layer provided on the conductive layer of the copper-clad laminate .

When the content of the fine solid powder contained in the photosensitive layer is more than the above range, the transmittance of the obtained photosensitive material is deteriorated, and it is difficult to obtain a desired center line average roughness of the photosensitive layer surface. And it becomes difficult to print a high-resolution image on a laminate in close contact. On the other hand, when the content of the solid fine powder is less than the above range, a photomask obtained from the photosensitive material is stacked on the laminate, and air existing between the photomask and the photosensitive resin layer provided on the conductive layer is removed. Disadvantages such as a long suction time when removing by suction under a high vacuum occur.

If the average roughness of the center line of the surface of the photosensitive layer is larger than the above range, the amount of irregular reflection of light by the photosensitive layer increases, so that the transmittance of the obtained photosensitive material is deteriorated and the photosensitive layer provided on the conductive layer is deteriorated. It becomes difficult to adhere a high-resolution image to the conductive resin layer. On the other hand, when the center line average roughness of the photosensitive layer surface is smaller than the above range, the photomask obtained from the photosensitive material is superimposed on the photosensitive resin layer provided on the conductive layer, and the distance between the photomask and the photosensitive resin layer is reduced. When sucking and removing air present in the air, it becomes difficult to suck and remove the air, and it takes time to suck and remove the air.
Since bubbles are likely to remain between the photomask and the photosensitive resin layer, it becomes difficult to efficiently and stably perform close-contact printing of a high-resolution image on the photosensitive resin layer.

The light-sensitive material of the present invention has a non-image portion (transparent portion) having an average light transmittance of 40% or more with respect to all light in the wavelength range of 300 to 500 nm. When the transmittance is lower than this, when a photomask obtained from a photosensitive material is overlaid on the photosensitive resin layer provided on the conductive layer and irradiated with ultraviolet light from above to print an image on the photosensitive resin layer,
Since the amount of light transmitted through the non-image portion (transparent portion) of the photomask is small, problems such as insufficient photocuring reaction of the photosensitive resin layer occur, and efficient and stable close contact printing cannot be performed. The transmittance of the photosensitive material depends on the type and thickness of the support, the particle size and amount of the solid fine powder contained in the photosensitive layer, the center line average roughness of the photosensitive layer surface, the thickness of the photosensitive layer, and the thickness of the photosensitive layer. By appropriately selecting the amount of the auxiliary component to be contained, the amount can be controlled to a desired range.

The light-sensitive material of the present invention can form a color image or a transparent image on the film surface by performing exposure and development in the same manner as a normal diazo photosensitive film. In this case, a mercury lamp can be used for exposure, and an alkali agent such as ammonia gas can be used for development. The image on the film obtained by such exposure and development is a positive image, the exposed portion is transparent, and the unexposed portion is a dye portion (colored portion). Therefore, in order to form a color image, exposure and development may be performed using a positive film having an opaque image as an original image film.
In order to obtain a transparent image, exposure and development may be performed using a negative film having a transparent image as an original film. The photosensitive material on which the color image or the transparent image thus obtained is formed is applied as a photomask.

In order to preferably manufacture a photomask using the photosensitive material of the present invention, an original film is placed on a transparent support plate of a vacuum contact printing machine, and the photosensitive material of the present invention is placed thereon with the photosensitive layer face down. , And a cover is placed thereon, and a vacuum is applied between the cover and the transparent support plate. As a result, the air between the original film and the photosensitive layer surface of the photosensitive material is quickly sucked and removed, and the two closely adhere. Next, in this state, ultraviolet rays are irradiated from below the transparent support plate to print the image of the original film on the photosensitive material. After the completion of the contact printing, the photosensitive material is brought into contact with an alkaline agent such as ammonia to develop the photosensitive material. In this way, a photomask made of a photosensitive material on which a color image or a transparent image is formed can be obtained.

In order to adhere the image of the photomask obtained as described above to the photosensitive resin layer provided on the conductive layer of the copper-clad laminate, the book is placed on a transparent support plate of a vacuum adhesion printer. A photomask obtained from the photosensitive material of the present invention is placed with its image surface facing up, a copper-clad laminate is laid thereon with the photosensitive resin layer facing down, and a cover is laid thereon, and the A vacuum is applied between the cover and the transparent support plate.
As a result, the air between the photomask and the photosensitive resin layer is quickly sucked and removed, and the two closely adhere. Next, in this state, ultraviolet rays are irradiated from below the transparent support plate, and the image of the photomask is printed on the photosensitive resin layer. Then, the photosensitive resin layer on which the image has been printed in this manner is developed to form a surface portion composed of a cured resin portion and an exposed copper portion. Next, this surface is subjected to an etching treatment to elute and remove the exposed copper portion, and then the remaining cured resin portion is removed. Thus, a printed wiring board having a predetermined wiring pattern is obtained.

[0022]

The light-sensitive material of the present invention has a thickness of 300 to 500 n.
Because of its excellent transmittance for light of wavelength m,
By forming an image on this, it is possible to obtain a photomask having excellent transmittance in a non-colored portion (transparent portion) and high adhesion baking efficiency. Moreover, the photosensitive material of the present invention
The thickness of the photosensitive layer is defined in the range of 4 to 14 μm, and the photosensitive layer is limited to 0.5 to 5% by weight of a solid fine powder having an average particle diameter of 1 to 8 μm. Amount, and the center line average roughness of the photosensitive layer surface is specified in a specific range of 0.05 to 0.3 μm. Very good adhesion. Therefore, when the original film is superimposed on the photosensitive material of the present invention, and the air existing between the photosensitive material and the original film is suctioned and removed under vacuum conditions, and the two are brought into close contact with each other, the time for sucking and removing the air is reduced. In addition to shortening, the obtained adhered body is a highly adhered body having no air bubbles remaining between the photosensitive material and the original film. Then, by irradiating the adhered body with ultraviolet rays, the image of the original film can be printed on the photosensitive material with high resolution.

In the photomask obtained from the photosensitive material of the present invention, since the image formed on the surface thereof has a high resolution, the photomask is formed on the surface of the photosensitive resin layer provided on the conductive layer of the copper clad laminate. By performing close contact baking, a high-resolution image can be formed on the photosensitive resin layer. Moreover, this photomask has a transparent portion of 300 to 500
Because of its excellent transmittance for light with a wavelength of nm,
When this is brought into close contact with the photosensitive resin layer and exposed using ultraviolet light, efficient printing can be performed. Further, this photomask has a surface on the image portion side of 0.05 to
Since it is formed on a rough surface having a center line average roughness in the range of 0.3 μm, the adhesiveness to the photosensitive resin layer surface is extremely excellent. That is, when the photomask is placed on the surface of the photosensitive resin layer, and air existing between the photomask and the photosensitive resin layer is removed by suction under vacuum conditions, and the two are brought into close contact with each other, the air is removed by suction. The time required to perform the process is shortened, and the obtained contact body is a highly adherent body in which no air bubbles remain between the photomask and the photosensitive resin layer. Then, by irradiating the adhered body with ultraviolet rays, the image of the photomask can be printed on the photosensitive resin layer at a high resolution, and finally, a printed wiring board having a high-resolution wiring pattern Can be obtained. In the photosensitive material of the present invention and the photomask obtained therefrom, the surface of the photosensitive layer is formed rough, so that the surface on the photosensitive layer side can be easily known by hand. Therefore, the photosensitive material of the present invention and the photomask obtained therefrom have the advantage that the front and back can be easily distinguished. Since the photosensitive material of the present invention and the photomask obtained therefrom have a rough photosensitive layer surface, they are scratched when the photosensitive layer hits a corner of a desk or a projection on a desk during operation. Hateful. Therefore, the photosensitive material of the present invention and the photomask obtained therefrom have the advantage that the photosensitive layer is not easily damaged. Since the photosensitive material of the present invention and the photomask obtained therefrom have a rough photosensitive layer surface, they can be modified with a pencil, pen or the like. Therefore, the light-sensitive material of the present invention and the photomask obtained therefrom have the advantage that corrections can be made easily.

[0024]

Next, the present invention will be described in more detail by way of examples.

Example 1 A polyester film having a thickness of 175 μm was used as a base film. On one side of this substrate film, a coating solution having the following component composition prepared by a conventional method was applied and dried to prepare a diazo photosensitive film having a photosensitive layer of 10 μm. (Coating liquid) Methyl ethyl ketone 40 parts by weight Methyl cellosolve 40 parts by weight Synthetic silica (average particle size 3.5 μm) 0.17 parts by weight Cellulose resin 8.41 parts by weight Modified vinyl acetate resin 3.61 parts by weight Acrylic resin solution 4.00 Parts by weight sulfosalicylic acid 0.07 parts by weight thiourea 0.14 parts by weight zinc chloride 0.14 parts by weight β-resorcylic acid ethanolamide 0.06 parts by weight o-phenylphenol 1.70 parts by weight Formula (I) diazo compound 1.44 part by weight _{^{(R 1 = CH 3, R}} 2 = CH 3, X = PF 6 -) methyl violet solution (concentration 0.4%) 0.28 parts by weight of surfactant solution 0.36 parts by weight

Example 2 A diazo photosensitive film was prepared in the same manner as in Example 1 except that the average particle size of the synthetic silica was changed to 2.5 μm.

Example 3 A diazo photosensitive film was prepared in the same manner as in Example 1 except that the content of the synthetic silica was changed to 0.35 parts by weight.

Comparative Example 1 A diazo photosensitive film was prepared in the same manner as in Example 1 except that the average particle size of the synthetic silica was changed to 10 μm.

Comparative Example 2 A diazo photosensitive film was prepared in the same manner as in Example 1 except that the average particle size of the synthetic silica was changed to 0.50 μm.

Comparative Example 3 A diazo photosensitive film was prepared in the same manner as in Example 1 except that the content of the synthetic silica was changed to 2.0 parts by weight.

Comparative Example 4 A diazo photosensitive film was prepared in the same manner as in Example 1 except that the thickness of the photosensitive layer was changed to 20 μm.

Comparative Example 5 A diazo photosensitive film was prepared in the same manner as in Example 1 except that the thickness of the photosensitive layer was changed to 3 μm.

Comparative Example 6 A diazo photosensitive film was prepared in the same manner as in Example 1 except that synthetic silica was not contained.

The characteristics of the diazo photosensitive films obtained above are shown in Table 1, and the diazo photosensitive films were tested as follows. Table 1
The content (% by weight) of the solid fine powder shown in the above is the content of the solid fine powder contained in the photosensitive layer. Further, the average light transmittance (%) is a light transmittance curve [horizontal axis: wavelength (nm), vertical axis: light transmittance (%)] prepared for a non-image portion (transparent portion) of the diazo photosensitive film. , The integrated value of the light transmittance at a wavelength of 300 to 500 nm
It is a value divided by the length of the horizontal axis between 500 nm. Further, the center line average roughness (μm) indicates the center line average roughness of the photosensitive layer surface and is measured according to JIS B0601.

Test 1 A negative film on which a print pattern was formed was placed on a sample film, exposed with a high-pressure mercury lamp, and developed with ammonia. The average light transmittance of the transparent part and the non-image part (transparent part) of the obtained film (photomask) with respect to all light having a wavelength of 300 to 500 nm was measured.

Test 2 Using the film obtained above, the photosensitive resin layer provided on the conductive layer of the copper-clad laminate was baked by a vacuum adhesion printer to form a pattern, and the baked pattern was formed. Were evaluated for image resolution and adhesion. The evaluation was performed in five stages, with 5 being good and 1 being bad.

Test 3 The density of the image area (colored area) of the film obtained in Test 1 was measured and evaluated. The evaluation was performed in five stages, with 5 having a high concentration and 1 being a low concentration.

Test 4 The same photosensitive resin layer as used in Test 2 was baked with the film obtained in Test 1 on a vacuum contact printing machine using a baking time (vacuum evacuation time + exposure time). Time), the printing characteristics of the photosensitive material were evaluated. Evaluation is 5
The test was performed in stages, and the time was short, and 5 was long, and 1 was long. Table 2 summarizes the results of Tests 1 to 4 above.
Shown in

From the results shown in Table 2, the products of the present invention (Examples 1 to 3)
It can be seen that 3) is a diazo photosensitive material having good image resolution, adhesion, and printing characteristics.

[0040]

[Table 1]

[0041]

[Table 2]

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-104247 (JP, A) JP-A-4-51142 (JP, A) JP-A-58-10740 (JP, A) JP-A-48-48 45304 (JP, A) Japanese Utility Model Showa 52-13102 (JP, U) Japanese Patent Publication No. 4-76461 (JP, B2) (58) Field surveyed (Int. Cl. ⁶ , DB name) G03C 1/52

Claims (1)

(57) [Claims] 1. A compound of the general formula (Wherein R ¹ and R ² represent lower alkyl groups and X represents an anion), phenylphenol, N- (2′-hydroxy lower alkyl) -β-resorcylamide, and a Coulter counter method. Thickness containing solid fine powder having an average particle size of 1.0 to 8.0 μm according to
A photosensitive layer having a thickness of 0.5 to 14 μm formed on a transparent support film, wherein the content of the solid fine powder in the photosensitive layer is 0.5
5% by weight, the center line average roughness of the photosensitive layer surface is 0.05-
A diazo photosensitive material having an average light transmittance of 40% or more in a non-image portion (transparent portion) with respect to all light having a wavelength of 0.30 μm and a wavelength of 300 to 500 nm.