JPH0145052B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a method for forming a resist pattern using a dry film resist with excellent workability. [Prior Art] Dry film resists are mainly used as etching resists and plating resists for forming conductor patterns during the manufacture of printed circuit boards. Such dry film resists include, for example, Du Pont Co.'s “Riston”;
“Laminar” by Dynachem Corp., Hitachi Chemical
There is “Hitachi Photosensitive Resist Film” by Co., Ltd.
All of these are composed of an acrylate polymer, an acrylate monomer, a storage stabilizer, a dye, and a photopolymerization initiator. Since these compositions contain acrylate monomers and are soft and sticky, they are handled by being sandwiched between a support film such as a polyester film and a protective film such as a polyolefin film. but,
Even if these compositions are handled in this form, if they are stored at high temperatures for a long period of time, the compositions may bulge out from both sides of the support film, impairing the opening properties of the film, and may cause discomfort peculiar to acrylate monomers. It has an odor, the photosensitive layer is sticky, so the photomask cannot be brought into close contact with the photomask when printing the image, and the printing must be done through the support film, making it difficult to obtain a clear image.Furthermore, the film is brittle after being photocured. It has the disadvantage that images created by photocuring tend to peel off. In addition to etching and plating resist,
A field in which resist is used in the form of a dry film is solder resist for printed circuit boards, but because heat resistance is required, commercially available etching and plating resists cannot be used as they are as solder resists. Commercially available dry films for solder resists are acrylate-based photosensitive resin compositions, but they have the same drawbacks as the dry film resists for etching and plating resists, and they do not have sufficient heat resistance. The problem is that it is not. [Problems to be Solved by the Invention] The present invention was made against the background of the above-mentioned conventional technical problems, and is useful as a method for forming etching, plating, and solder resist, and provides a resist pattern with excellent workability. The purpose is to provide a forming method. [Means for Solving the Problems] That is, the present invention provides a polybutadiene cyclized product (hereinafter simply referred to as "(a) polybutadiene cyclized product") which is formed on a support and satisfies the following formulas () to (). monster"
That's what it means. ), (b) at least one of a photocrosslinking agent, a photosensitizer, and a photopolymerization initiator, and (c) a storage stabilizer. The present invention provides a method for forming a resist pattern, which is characterized by laminating a workpiece with heat, then peeling off the support if it remains, exposing it to light through a negative film, and developing it. () 30000≦MW≦300000 () DC／10≧9.5−logMW () DC／5≦8.5＋logMW () 40≦DC≦70 () 0.3≦[η]30° Toluene≦0.7 (In the formula, MW is the raw material molecular weight of polybutadiene,
DC is the cyclization rate (%) of polybutadiene cyclized product, [η]
30° Toluene represents the intrinsic viscosity (dl/g) of the polybutadiene cyclized product. ) The polybutadiene cyclized product (a) used in the present invention is one in which the molecular weight of the raw material polybutadiene, the cyclization rate of the cyclized product, and the intrinsic viscosity [η] are within specific ranges. In other words, the molecular weight of the raw material polybutadiene is 30,000~
300,000, and if the molecular weight is less than 30,000, the image obtained by photocuring will be brittle when used as a dry film, and the molecular weight will be too low.
If it exceeds 300,000, a high temperature is required when laminating the dry film onto the substrate, and therefore, there is a drawback that thermal fogging of the dry film cannot be completely prevented. In addition, the cyclization rate is in the range of 40 to 70%, and when the cyclization rate is less than 40%, the polybutadiene cyclized product exhibits rubbery properties,
It has the disadvantage that it protrudes from both sides of the support film during storage, and if the cyclization rate exceeds 70%, the flexibility of the dry film decreases, making it particularly difficult to laminate to copper-clad laminates. Furthermore, the intrinsic viscosity of the cyclide [η] is 30°, and toluene is 0.3
~0.7 (dl/g), [η]30° Toluene
If it is less than 0.3, the dry film and its photocured portion will be brittle and unusable, and if [η]30° toluene exceeds 0.7, there will be a drawback that the thickness of the dry film will become more uneven. Furthermore, in the polybutadiene cyclized product (a) within the above range, the cyclization rate (DC) of the cyclized product and the molecular weight (MW) of the raw material polybutadiene satisfy the following formulas () and (). This eliminates the stickiness of the resulting dry film, allowing it to be exposed with a photomask in close contact with it. () DC/10≧9.5−logMW () DC/5≦8.5+logMW (a) The photocrosslinking agent, photosensitizer, and photopolymerization initiator added to the polybutadiene cyclized product include, for example. Examples include: That is, as a photocrosslinking agent, an azide such as 2,6-bis(4'-azidobenzal)cyclohexanone, bis(4-azidobenzal)acetone, 4,4'-diazidostilbene, p-azidobenzalacetophenone is used. Compounds; photosensitizers include p,p'-tetramethyldiaminobenzophenone, benzophenone, anthraquinone, 1,2-benzanthraquinone, carbonyl compounds such as bioanthrone, 5-nitroacenaphthene, α-nitronaphthalene , nitro compounds such as 2-nitrofluorene; Examples of photopolymerization initiators include benzoin-based compounds such as benzoin, beyzoin methyl ether, benzoin isopropyl ether, benzoin dimethyl ketal, and sulfur compounds such as diphenyl sulfide. be able to. These compounds exhibit the greatest effect when used alone or in combination of two or more in an amount of 0.1 to 10% by weight based on (a) the polybutadiene cyclized product. As the storage stabilizer (c) used in the present invention, for example, 2,2'-methylenebis(4-thymel-6-
t-butylphenol), 2,2'-methylenebis(4-ethyl-6-t-butylphenol), 2,
Alkylphenol compounds such as 6-di-t-butyl-p-cresol; aromatic amine compounds such as phenyl-β-naphthylamine, diphenyl-p-phenylenediamine, phenylisopropylphenylenediamine; lauryl thiodipropionate, 4,4'-thiobis(6-t
-butyl-m-cresol), 2(3,5-di-t
-Butyl-4-hydroxyanilino)-4,6-
There are sulfur-based compounds such as bis(N-octylthio)-1,3,5-triazine, etc., and one or more of these can be mixed in an amount of 0.1 to 5% by weight based on (a) polybutadiene cyclized product. It is added and used. Depending on the use of the dry film used in the present invention, the formed image may be visually inspected, so it is desirable that the dry film itself be colored to make it easier to see. Coloring can be done using dyes and/or pigments. Although essentially any dye or pigment may be used, it is necessary that the image of the photocured portion remaining after development is colored. Therefore, it is preferable that it is difficult to extract with a halogenated hydrocarbon such as 1,1,1-trichloroethane, which is a commonly used developer, and an insoluble one is preferably used. For something like this, CI
Pigment Orange14 (CI21165), CIPigment
Azo compounds such as Red13 (CI12395), CI
Pigment Blue15 (CI74160), CIPigment
Phthalocyanine compounds such as Green7 (CI74260), CIPigment Blue22 (CI69810), CIVat
Anthraquinone compounds like Orange3, CI
Vat Orange7 (CI71105), CIVat Red15 (C.
Perinone compounds such as I.71100), CIVat
Indigoid compounds such as Violet3 (CI73395), carbonium compounds such as CIPigment Red81 (CI45160), CIViolet19 (CI46500)
Examples include quinacridone compounds such as. The amount of these dyes and/or pigments used is from 0.01 to (a) polybutadiene cyclized product.
It is used by adding 3.0% by weight. If the amount of dye and/or pigment added is more than 3.0% by weight, the dye and pigment will absorb a large amount of light, and sufficient photocuring will not occur. In the present invention, (a) polybutadiene cyclized product,
(b) at least one of a photocrosslinking agent, a photosensitizer and a photoinitiator; (c) a storage stabilizer and if necessary a dye and/or pigment; toluene, xylene,
A support in which a homogeneous composition is made using a solvent such as tetrachlorethylene and then subjected to release treatment on a film such as polytetrafluoroethylene, polyethylene film, polyethylene terephthalate film, other plastic films, laminated paper, etc. It is applied onto the body and dried to produce a dry film with a thickness of 10 μm to several hundred μm. The dry film thus obtained can be easily laminated to a workpiece by heat, either as it is or after peeling off the support. After laminating the workpiece, if any dry film support remains, the support is peeled off, exposed to light through a negative film, and developed. Here, examples of the developer used for development include hydrocarbon solvents. [Examples] Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to the following Examples unless the gist thereof is exceeded. Example 1 Cis-1,4-polybutadiene (molecular weight 45000,
cis-1,4-content 96%) was cyclized in toluene to obtain a cyclized product with a cyclization rate of 56% and [η]30° toluene=0.54. Toluene solution with cyclide concentration of 27.8% by weight
Cyanyl blue (CI74160) 0.278 per 100g
g, benzoin isopropyl ether 1.39 g,
0.278 g of 4,4'-thiobis(6-t-butyl-m-cresol) was added, and a homogeneous composition was prepared using a ball mill. This composition is made into a polyester film [Fujimori Industries Co., Ltd.]
Co., Ltd. BYNASHEET 38E-001C]
It was dried at 80° C. for 1 hour to form a film with a thickness of 17 μm. Next, the composition film was peeled off from the support film, and then laminated by pressing with a rubber roller at a feed rate of 1 m/min onto a copper-clad laminate that had been preheated to 120°C. A test pattern photomask with a minimum width of 100 μm was closely attached to the laminated film, and after exposure for 20 seconds to ultra-high pressure mercury lamp light with a light intensity of 270 W/m ² , a developer for microphotoresist [manufactured by Nippon Gosei Rubber Co., Ltd.] was applied. , J.S.R.
When developed with DEVELOPERG-005, a hydrocarbon solvent, a clear colored image was obtained with no peeling of the film. The copper-clad laminate having this colored image was slightly warped, but no peeling of the image was observed. Etching was then carried out at 60° C. for 10 minutes using a 25% by weight aqueous ferric chloride solution by dipping. When the resist was removed by rubbing with a piece of cloth soaked in methylene chloride, a copper foil pattern faithful to the mask was obtained. Example 2 The same process as in Example 1 was carried out except that the following compound was used instead of benzoin isopropyl ether and the exposure time was changed, but the results were the same as in Example 1. Amount used Exposure seconds p,p'-tetramethyldiamino
1.39g 20 seconds Benzophenone p,p'-tetramethyldiamino
0.14g 20 seconds BenzophenoneBenzophenone 0.21g Ha 2,6-bis(4′-azidobenzal)
0.70g 1 second Cyclohexanone Example 3 In Example 1, 4,4'-thiobis(6-t-
Exactly the same treatment was performed except that the following compound was used instead of (butyl-m-cresol), but the results were exactly the same as in Example 1. A 2(3,5-di-t-butyl-4-hydroxyanilino)-4,6-bis(N-octylthio)-1,3,5-triazine 0.278g B 2,2'-methylenebis(4- ethyl-6-t
-butylphenol) 0.278g Example 4 A composition was prepared in exactly the same manner as in Example 1 except that the following substance was used instead of cyanine blue, and after forming it into a dry film, it was laminated on a copper viscose laminate, It was exposed and developed to obtain a colored image. The subsequent operations were performed in the same manner as in Example 1, and similar results were obtained. Compounds used in place of cyanine blue Heat resistance, flexibility A CIViolet19 Same as Example 1 CIVat Orange3 CIPigment Green7 Example 5 Cis-1,4-polybutadiene (molecular weight 45000,
(cis-1,4 content: 96%) was cyclized in toluene to obtain a cyclized product with a cyclization rate of 62% and [η] 30° toluene = 0.36. Using this cyclized product, the subsequent operations were carried out in the same manner as in Example 1 to obtain a uniform composition. The same treatment as in Example 1 was performed except that this composition was used and the exposure time was changed to 25 seconds, and the same results as in Example 1 were obtained. Example 6 Cis-1,4-polybutadiene (molecular weight 45000,
Cis-1,4 content 88%, trans-1,4 content 5
%) in toluene, the cyclization rate was 51%, [η]
A cyclized product of 30° toluene = 0.43 was obtained. Cyclide concentration 30.0
To 100 g of wt% toluene solution, 0.15 g of p,p'-tetramethyldiaminobenzophenone, 0.375 g of bezophenone, 0.30 g of 4,4'-thiobis(6-t-butyl-m-cresol), 2,2' -Methylenebis(4-methyl-6-t-butylphenol)
0.30g, CIPigment Green7 (CI74260) 0.15g
was added, and a homogeneous composition was prepared using a ball mill. Paper treated with this composition as a release agent [manufactured by Fujimori Industries Co., Ltd.]
BYNASHEET70X-532] and dried at 80°C for 1 hour to form a film with a thickness of 22 μm. Next, peel off the composition film from the release-treated paper,
Lamination was carried out at a speed of 90 cm/min onto a copper-clad laminate that had been preheated to 110°C. The laminated film is then passed through a test pattern to measure the light intensity.
After exposure for 60 seconds to ultra-high pressure mercury lamp light of 270 W/m ² , development was performed for 2 minutes at room temperature using 1,1,1-trichloroethane by the immersion method to obtain a colored image. After further post-curing the colored image at 160°C for 30 minutes, it was immersed in a solder bath at 260°C 10 times for 10 seconds each.
No changes were made. Example 7 Cis-1,4-polybutadiene (molecular weight 45000,
Cis-1,4 content 88%, trans-1,4 content 5
%) in toluene, the cyclization rate was 63%, [η]
A cyclized product of 30° toluene = 0.51 was obtained. Using this cyclized product, a uniform composition was obtained in the same manner as in Example 6. The same treatment as in Example 6 was performed except that this composition was used and the exposure time was changed to 70 seconds, and the same results as in Example 6 were obtained. Example 8 Cis-1,4-polybutadiene (molecular weight 67000,
(cis-1,4 content: 96%) was cyclized in toluene to obtain a cyclized product with a cyclization rate of 56% and [η] 30° toluene = 0.54. Toluene solution with cyclide concentration of 27.8% by weight
Cyanine blue (CI74160) 0.278 per 100g
g, benzoin isopropyl ether 1.39 g,
0.278 g of 4,4'-thiobis(6-t-butyl-m-cresol) was added, and a homogeneous composition was prepared using a ball mill. This composition is made into a polyester film [Fujimori Industries Co., Ltd.]
Co., Ltd. BYNASHEET 38E-001C]
It was dried at 80°C for 1 hour to form a film with a thickness of 17 μm. Next, the composition film was peeled off from the support film, and then laminated by pressing with a rubber roller at a feed rate of 1 m/min onto a copper-clad laminate that had been preheated to 120°C. A test pattern photomask with a minimum width of 100 μm was closely attached to the laminated film, and after exposure for 20 seconds to ultra-high pressure mercury lamp light with a light intensity of 270 W/m ² , a developer for microphotoresist [manufactured by Nippon Gosei Rubber Co., Ltd.] was applied. J.S.R.
DEVELOPER G-005, hydrocarbon solvent], a clear colored image was obtained. Next, use a borofluoric acid plating bath to remove approximately 7μ
Solder plating was performed to a thickness of m. After removing the resist by rubbing with a cloth impregnated with methylene chloride, etching was performed using an ammonium persulfate bath. As a result, a clear image of the solder-plated copper foil was obtained. Comparative Example 1 Cis-1,4-polybutadiene (molecular weight 45000,
The same procedure as in Example 1 was carried out except that a cyclized product obtained by cyclizing cis-1,4 (96% content) in toluene with a cyclization rate of 38% and [η] 30° toluene = 0.73 dl/g was used. , a homogeneous composition was obtained. The obtained composition was made into a dry film in the same manner as in Example 1, and after being stored at room temperature for 45 days, an attempt was made to peel the dry film from the support film, but the composition protruded from both sides of the support film and the dry film was removed. I couldn't peel it off properly. Comparative Example 2 Cis-1,4-polybutadiene (molecular weight 45000,
Cis-1,4 content 88%, trans-1,4 content 5
%) in toluene, the cyclization rate was 72%,
[η] 30° A uniform composition was obtained in the same manner as in Example 6 except that a cyclized product of toluene = 0.31 dl/g was used. The obtained composition was made into a dry film in the same manner as in Example 6, and was laminated onto a copper-clad laminate, exposed for 90 seconds, and developed, but because the lamination to the copper-clad laminate was not sufficient, the developer was not used for lamination. It penetrated into the film, and peeling of the film was observed. Example 3 Cis-1,4-polybutadiene (molecular weight 25000,
A homogeneous composition was prepared in the same manner as in Example 1 except that a cyclized product with a cyclization rate of 58% and [η] 30° toluene = 0.24 was obtained by cyclizing cis-1,4 (95% content) in toluene. I got something. The resulting composition was made into a dry film in the same manner as in Example 1, laminated onto a copper laminate, exposed, and developed to obtain a colored image. When the copper viscose laminate having this colored image was slightly warped, some peeling of the image was observed. Above, Examples 1 and 5 to 8 and Comparative Example 1
The data of formulas () to () above for component (a) of ~3 are shown in Table 1.

〔Effect of the invention〕

The dry film used in the present invention does not contain any volatile monomers, so it does not have an unpleasant odor, and by using a specific polyester cyclized product, the composition remains stable even when stored at high temperatures for long periods of time. It does not protrude from both sides and impair the opening properties of the film, and it is not sticky at room temperature and can be handled as a single layer film.
Because it can be exposed in close contact with the negative film and the film has excellent flexibility after being photocured, it has the advantage of printing clear images without peeling. In addition, when the resist pattern obtained by the present invention is used as a solder resist, it has sufficient heat resistance, and like commercially available acrylate products, it can be used as a solder resist.
There is no limit to 260℃ soldering only once (approximately 10 seconds), and the feature is that it can withstand 260℃ for 10 minutes. Furthermore, the method of the present invention allows the dry film to be easily laminated onto the workpiece by heat, and is a method with excellent workability.

Claims (1)

[Scope of Claims] 1. Formed on a support, (a) the following () to
A dry film consisting of a composition containing a polybutazine cyclized product satisfying the formula (), (b) at least one of a photocrosslinking agent, a photosensitizer, and a photopolymerization initiator, and (c) a storage stabilizer is used as it is, or After peeling off the support, it is laminated onto the workpiece using heat.
A method for forming a resist pattern, which comprises: then peeling off the support if it remains, exposing it to light through a negative film, and developing it. () 30000≦MW≦300000 () DC／10≧9.5−logMW () DC／5≦8.5＋logMW () 40≦DC≦70 () 0.3≦[η]30° Toluene≦0.7 (In the formula, MW is the raw material molecular weight of polybutadiene,
DC is the cyclization rate (%) of polybutadiene cyclized product, [η]
30° Toluene represents the intrinsic viscosity (dl/g) of polybutadiene cyclized product. )