TWM543773U - Photosensitive dry film - Google Patents

Description

Photosensitive dry film

The present invention relates to a dry film and an application thereof, and more particularly to a photosensitive dry film comprising a support substrate having a non-smooth structure and a photosensitive resin layer, and the photosensitive dry film for preparing a matte photosensitive development cover film Application.

Flexible printed circuit boards are widely used in various 3C products, optical lens modules, LCD modules, solar cells and other products. The traditional soft printed circuit board is mainly produced by using protective rubber and liquid anti-weld green paint to provide a circuit cover on the surface of the circuit board to protect the copper circuit on the surface of the soft board and increase the bending resistance of the line. . However, the conventional protective rubber and liquid anti-weld green paint have the disadvantages of low resolution and poor flexibility in application, and it is usually required to use the two at the same time, thus complicating the production process of the flexible printed circuit board. Therefore, circuit protection of a flexible printed circuit board is often carried out by using a photosensitive photomaskable cover (PIC) capable of forming a fine opening pattern and having both resolution and flexibility.

Modified acrylate or polyimide (PI) is a common photosensitive development film material, which can meet the mechanical strength of flexible circuit boards. Requirements for flexibility, solvent resistance, dielectric properties, and heat resistance. However, the protective film formed by curing the modified acrylate is transparent and colorless, and the protective film formed by curing the polyimide is transparent and slightly yellow. When the above material is covered on the flexible circuit board, it can still be observed. A circuit pattern that is placed on a flexible circuit board. Further, the above protective film has a characteristic of high glossiness, and there is still room for improvement in terms of matte surface and aesthetics.

In view of the above technical problems, the present invention aims to provide a photosensitive dry film for forming a cover film with excellent resolution and low gloss, which can provide protection and anti-spy function for circuits on a flexible printed circuit board, and both Aesthetic.

Therefore, an object of the present invention is to provide a photosensitive dry film comprising a support substrate and a photosensitive resin layer on the support substrate, wherein the support substrate comprises a first surface in contact with the photosensitive resin layer And a second surface opposite the first surface, and the first surface has a non-smooth structure.

In some embodiments of the present invention, the first surface of the support substrate has a gloss of less than 15 GU as measured by the ASTM D523 standard method.

In some implementations of the present invention, the average roughness (Ra) of the first surface is between 110 nm and 850 nm higher than the roughness of the second surface.

In some implementations of the present invention, the second surface has a smooth structure.

In some implementations of the present invention, the first surface has an average roughness (Ra) of 260 nm to 1000 nm, and the center line of the surface to be tested can be measured using a 3D roughness meter, an interferometer, or an atomic force microscope. Average surface roughness.

In some embodiments of the present invention, the support substrate has a thickness of from 10 micrometers to 250 micrometers.

In some embodiments of the present invention, the support substrate is a polyester film or a polyolefin film.

In some embodiments of the present invention, the photosensitive resin layer is formed by drying a photosensitive resin composition on the first surface of the support substrate, and the photosensitive resin composition comprises 15% by weight to 80%. % by weight of the polymer binder, 2% by weight to 65% by weight of the unsaturated group-containing photopolymerizable compound, and 0.5% by weight to 20% by weight of the photoinitiator. The polymer binder may be an acrylic binder or a polyimide-based binder, and the unsaturated group-containing photopolymerizable compound may be an acrylate group-containing photopolymerizable compound.

In some embodiments of the present invention, the photosensitive resin composition further contains an additive.

In order to make the above objects, technical features and advantages of the present invention more obvious, the following detailed description will be made in detail.

1‧‧‧ release layer

2‧‧‧Photosensitive resin layer

4‧‧‧Support substrate

5‧‧‧Substrate

Fig. 1 is a schematic view showing an embodiment of a photosensitive dry film of the present invention.

Fig. 2 is a flow chart showing the preparation of a photosensitive development cover film using the photosensitive dry film of the present invention.

In the following, some specific embodiments according to the present invention will be specifically described; however, the present invention can be in various forms without departing from the spirit of the present invention. As such, the scope of this Creative Protection should not be construed as limited to the description or the drawings. In the figures, the dimensions of the various items and regions may be exaggerated for clarity and not drawn to the actual scale. In addition, the terms "a", "an" and "the"

The photosensitive dry film of the present invention comprises a support substrate and a photosensitive resin layer on the support substrate, and a technical feature is that the surface of the support substrate in contact with the photosensitive resin layer has a non-smooth structure. Compared with the dry film using a support substrate having a smooth structure, the photosensitive dry film of the present invention can provide a protective cover film structure with more excellent resolution and low gloss, and provides a fog black in addition to providing a protective function. Aesthetics and the effect of shielding the circuit.

Fig. 1 is a schematic view showing an embodiment of a photosensitive dry film of the present invention. In the present embodiment, the photosensitive dry film includes the support substrate 4 and the photosensitive resin layer 2 on the support substrate 4, and the surface of the support substrate 4 in contact with the photosensitive resin layer 2 is the first surface, and A surface opposite the surface is a second surface, the first surface having a non-smooth structure. In addition, in the embodiment, the photosensitive dry film further comprises a release layer 1 on the surface of the photosensitive resin layer 2 not in contact with the support substrate 4 to provide protection during storage of the photosensitive dry film. And the function of insulating the photosensitive resin layer 2. The release layer 1 may be a release material known in the art to which the present invention pertains, as long as it provides a desired protective function and does not leave a residue on the surface of the photosensitive resin layer 2 after the tear-off. The use of such a release layer is performed by a person having ordinary knowledge in the technical field to which the present invention belongs, and can be completed based on the usual knowledge of the present specification, and is not the technical weight of the present invention. The point is not described in this article.

The surface (first surface) of the support substrate of the photosensitive dry film which is in contact with the photosensitive resin layer has a non-smooth structure.

In order to produce a matte effect, the first surface described above has a low gloss characteristic. In some embodiments, the first surface of the support substrate has a gloss of less than 15 GU, such as a gloss of 14 GU, 13 GU, 12 GU or less, and preferably has a gloss of less than 10 GU, Gloss is measured according to the ASTM D523 standard method.

In order to make the photosensitive dry film have a matte effect and maintain good photosensitivity, the roughness of the first surface of the support substrate of the photosensitive dry film needs to be higher than the roughness of the second surface, that is, the second surface is compared It is relatively smooth on the first surface, and the roughness of the first surface is preferably 110 nm to 850 nm higher than the roughness of the second surface in terms of surface roughness (Ra).

In some embodiments, the second surface of the support substrate of the photosensitive dry film has a smooth structure. In some embodiments, the second surface smoothing structure of the support substrate has a surface roughness (Ra) of from 0 nm to 200 nm.

In some embodiments, the first surface of the support substrate of the photosensitive dry film has a surface roughness (Ra) of 260 nm to 1000 nm, preferably 280 nm to 800 nm. Degrees, for example, surface roughness of 300 nm, 350 nm, 400 nm, 450 nm, 500 nm, 550 nm, 600 nm, 650 nm, 700 nm, 750 nm or higher. If the surface roughness of the first surface is too low, for example, less than 260 nm, the gloss of the first surface will be too high to affect the sensitization of the original surface. The matte texture of the cover film formed by the exposure and development steps of the dry film; if the surface roughness of the first surface is too high, for example, higher than 1000 nm, it will adversely affect the exposure of the photosensitive film of the present invention. The resolution of the cover film pattern formed after the development step.

In order to make the photosensitive resin layer of the photosensitive dry film have a high resolution after the subsequent exposure and development steps, preferably, the single surface of the support substrate has a non-smooth structure, preferably a surface, more preferably, the roughness of the first surface of the supporting substrate is higher than the roughness of the second surface by 130 nm to 650 nm, for example, 150 nm, 200 nm, 300 nm, 400 nm. , 500 nm or higher.

The type of the support substrate of the photosensitive dry film is not particularly limited, and any substrate known in the art to which the present invention pertains can be used, and a transparent support substrate is preferably used. For example, a polyester film or a polyolefin film may be used as the support substrate. The polyester film is, for example, a polyethylene terephthalate (PET) film, and the polyolefin film is, for example, a polypropylene film. In addition, the thickness of the support substrate is not particularly limited as long as the desired support properties can be provided. Generally, the thickness of the support substrate can be from 10 micrometers to 250 micrometers, preferably from 12 micrometers to 50 micrometers, for example. 12 microns, 15 microns, 16 microns, 20 microns, 25 microns, 30 microns, 35 microns, 40 microns, or 45 microns, but this creation is not limited thereto.

The photosensitive resin layer of the photosensitive dry film is formed by coating and drying a photosensitive resin composition on the first surface of the support substrate, and the photosensitive resin composition can be used for alkaline circuit of a printed circuit board. Etching, gold plating, electroless nickel immersion gold (ENIG), etc. The photosensitive resin composition contains 15% by weight to 80% by weight of the polymer binder, 2% by weight to 65% by weight of the unsaturated group-containing photopolymerizable compound, and 0.5% by weight based on the total weight of the fat composition. % to 20% by weight of a photoinitiator. The coating can be carried out, for example, by a conventional method such as a roll coater, a comma coater, a gravure coater, an air knife coater, a die coater, or a bar coater. get on. The drying may be carried out, for example, at a temperature of from 70 ° C to 150 ° C for from about 5 minutes to about 30 minutes. The photosensitive resin composition may be any photosensitive protective rubber material which is conventionally used for circuit protection of printed circuit boards. In general, the photosensitive resin composition contains a main component such as a polymer binder, a photopolymerizable compound containing an unsaturated group, a photoinitiator, and a solvent.

Examples of polymeric binders that can be used in the present invention include, but are not limited to, acrylic resins, styrenic resins, epoxy resins, guanamine resins, guanamine epoxies, polyimine precursors, alkyd resins. a phenol resin, a urethane resin, an epoxy acrylate resin obtained by a reaction of an epoxy resin with (meth)acrylic acid, an acid-modified epoxy acrylate resin obtained by reacting an epoxy acrylate resin with an acid anhydride, and the foregoing a mixture of two or more.

The unsaturated polymer-containing photopolymerizable compound of the present invention is generally a monomeric or short-chain oligomer having an ethylenically unsaturated functional group and comprising a monofunctional, difunctional or polyfunctional group. The above ethylenically unsaturated functional acrylate group can be used in the present unsaturated group-containing photopolymerizable compound, and examples thereof include, but are not limited to, 1,4-butanediol di(meth)acrylate (1, 4-butanediol di(meth)acrylate), 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate Neopentylglycol di(meth)acrylate, polyethyleneglycol di(meth)acrylate, neopentyl glycol di(meth)acrylate adipate (neopentylglycol dipate di(meth)acrylate), neopentyllglycol di(meth)acrylate hydroxypivalate, dicyclopentdienyl di(dicyclopentdienyl di) (meth)acrylate), caprolactone modified dicyclopentdienyl di(meth)acrylate, allylated cyclohexyl (meth)acrylate ( Allylated cyclohexyl di(meth)acrylate), isocyanurate di(meth)acrylate, trimethylol propane tri(meth)acrylate , dipentaerythriol tri(meth)acrylate, erythritol tris(meth)acrylate, trimethyltris(meth)acrylate,tris(propylene) Ethyl triacetate (tris(acryloxyethyl)isocyanurate) Alcohol penta (meth) acrylate, dipentyl erythritol hexa(meth) acrylate, ethoxylated trimethyl methoxide propane triacrylate, propoxylate glycerol triacrylate, B A bisphenol A ethoxylate dimethacrylate, an aliphatic urethane oligomer, and a mixture of two or more of the foregoing.

In some embodiments of the present invention, the polymer binder is an acrylic based binder (for example, an acrylic resin) or a polyimide based binder (for example, a polyimide based binder). Precursor) And the unsaturated group-containing photopolymerizable compound is an acrylate group-containing photopolymerizable compound.

The photoinitiator which can be used in the present invention can provide free radicals after being irradiated by light, and initiates polymerization by the transfer of free radicals. The type of photoinitiator is well known to those of ordinary skill in the art, and examples include, but are not limited to, benzoin, benzoin alkyl ether, diphenylglyoxal. (benzyl), ketals, acetophenones, benzophenone, 9-phenylacridine, 4,4-dimethyl-amino-di 4,4-dimethyl-amino-benzophenone, thioxanthones, morpholono-propanone, α-hydroxyketone, n-phenylglycine, imidazole A polymer, and a mixture of two or more of the foregoing. In addition, suitable 9-phenyl acridine homologues, such as those disclosed in U.S. Patent No. 5,217,845, the disclosure of which is incorporated herein in

The photosensitive resin composition of the present invention may contain a solvent as needed, and the solvent usable in the present invention includes any inert solvent which does not react with other components of the photosensitive resin composition, and examples thereof include, but are not limited to, methanol, ethanol, and C. Alcohol, butanol, acetone, methyl ethyl ketone, N-methyl 2-pyrrolidone, methyl ethyl ketone, methyl cellosolve, ethyl cellosolve, butyl cellosolve, toluene , N,N'-dimethylformamide, propylene glycol monomethyl ether dimethyl hydrazine, diethyl hydrazine, phenol, o-cresol, m-cresol, p-cresol, xylenol, halogenated phenol , catechol, tetrahydrofuran, dioxane, dioxolane, cyclopropanediol methyl ether, tetraethylene glycol dimethyl ether, Γ-butyrolactone, hexamethyl-o-decylamine, propylene glycol methyl ether acetate, and a mixture of two or more of the foregoing.

In some embodiments of the present invention, the content of the polymer binder may be 15% by weight to 50% by weight based on the total weight of the photosensitive resin composition, and the content of the photopolymerizable compound containing an unsaturated group may be 2% by weight to 30% by weight, the photoinitiator may be included in an amount of 0.5% by weight to 5% by weight, and the balance is a solvent. Further, the photosensitive resin composition may optionally contain other additives known to those skilled in the art to prepare a photosensitive dry film, and examples of the additive include, but are not limited to, fillers (e.g., carbon black, cerium oxide, etc.). Alumina, etc.), a heat curing agent, a dye, a leveling agent, an antifoaming agent, and a flame retardant. The content of the above-mentioned additives can be adjusted by routine experimentation by those having ordinary knowledge in the art to which the present invention pertains. In some embodiments, carbon black is added to the photosensitive resin composition to make the photosensitive development cover film having a better matte black effect, which is visually matte black. It is not easy to get fingerprints, the appearance is good, and it has better anti-peep effect. The specific preparation method of the photosensitive resin composition will be exemplified in the following examples.

The photosensitive dry film of the present invention can be used to form a cover film for a protective circuit on the surface of a printed circuit board. The method for forming a photosensitive development cover film comprises: laminating the above-mentioned photosensitive dry film on a substrate to form a laminated structure including the substrate, the photosensitive resin layer, and the support substrate in sequence; At least a portion of the photosensitive resin layer, and removing the support substrate before or after the exposing step; and performing a developing step, wherein the unexposed portion of the photosensitive resin layer is removed in the developing step, and the photosensitive type The photosensitive development cover film is formed on the exposed portion of the resin layer.

The photosensitive development cover film described above has a gloss of less than 15 GU as measured by the ASTM D523 standard method.

Hereinafter, the method will be described by taking the photosensitive dry film state shown in Fig. 1 as an example. Fig. 2 is a flow chart showing the preparation of a photosensitive development cover film using the photosensitive dry film of the present invention. As shown in FIG. 2, the method for forming a photosensitive development cover film is included in the method of removing the release layer 1 for protection, and laminating the photosensitive dry film on a substrate 5 so that the photosensitive resin layer 2 is not One surface of the support substrate 4 is bonded to the substrate 5 to which the photosensitive development cover film is to be applied, and a laminated structure including the substrate 5, the photosensitive resin layer 2, and the support substrate 4 in this order is formed. Next, an exposure step is performed to expose at least a portion of the photosensitive resin layer in accordance with the photosensitive development cover film pattern to be formed. In the case where the support substrate 4 is a transparent substrate, the support substrate 4 can be removed before or after the exposure step, preferably after the exposure step, to remove the support substrate 4 to ensure that the formed cover film is low. Glossy properties. After the exposure is completed and the support substrate 4 is removed, a development step is performed to remove the unexposed portion of the photosensitive resin layer 2, and the photosensitive development film is formed by the exposed portion of the photosensitive resin layer 2.

The cover film formed by using the photosensitive dry film of the present invention has excellent resolution (90 micrometers or less) and has a matte texture on the profile, so that it is aesthetically pleasing and provides line protection. The function.

The present invention is further illustrated by the following specific embodiments, wherein the measuring instruments and methods used are as follows:

[Gloss test]

Use gloss meter (Model: VG2000; Nippon Denshoku Division), the value of Gloss 60° of the sample to be tested is measured by the ASTM D523 method.

[surface roughness test]

The surface roughness (Ra) of the sample to be tested was measured using a hand-held roughness meter (model: SURTRONIC S100 series) under the measurement range of 100 μm × 100 μm.

[resolution test]

Exposure with an exposure energy of 6 exposure dots, and spray development, after the development treatment, the cured photosensitive resin layer pattern was observed using an optical microscope to evaluate the resolution, and the minimum aperture of the dot pattern without residue was opened. (μm) as the minimum resolution.

[Fog black texture test]

The appearance of the cover film formed by curing the photosensitive resin layer was observed with the naked eye, and if the appearance of the cover film was foggy and the circuit design under the cover film could not be observed, it was evaluated as "○"; When the circuit design under the cover film was observed, it was evaluated as "X".

Example

<Preparation of photosensitive resin composition 1>

The ratio of the polymer binder, the unsaturated photopolymerizable compound, the photoinitiator, the thermosetting agent, the solvent, and the inorganic filler shown in the following Table 1 was stirred to obtain a photosensitive resin composition 1.

<Preparation of photosensitive resin composition 2>

(1) Preparation of polymer binder

First, a polyproline oligomer was prepared in the following manner. 21.81 g (0.1 mol) of pyromellitic dianhydride (PMDA) was dissolved in 126 g of N-methyl-2-pyrrolidinone (NMP) and the resulting mixture was heated. It was reacted to 50 ° C and stirred for two hours. Then slowly add 2.322 grams (0.02 mole) of 2-hydroxyethyl acrylate (2-hydroxyethyl) Acrylate, HEA), and maintained at a temperature of 50 ° C, and reacted for two hours with stirring. Thereafter, 18.018 g (0.09 mol) of 4,4'-diamino-diphenyl ether (ODA) is added to the mixture obtained by the reaction, after completely dissolved, The polyamido acid oligomer was obtained by reacting at a temperature of 50 ° C for 6 hours while stirring.

Next, a diamine monomer was prepared in the following manner. 10.814 g (0.1 mol) of p-phenylenediamine (pPDA) was added to the toluene solvent, and 42.006 g (0.2 mol) of trifluoroacetic acid anhydride (TFAA) was slowly added with stirring. The reaction was carried out for one hour while maintaining the temperature at 50 ° C under stirring to obtain a diamine monomer.

200 g of the polyaminic acid oligomer (solid content: 25%) and 3 g of the diamine monomer were uniformly mixed to obtain a polymer binder.

(2) Preparation of photosensitive resin composition 2

The ratio of the polymer binder, the unsaturated photopolymerizable compound, the photoinitiator, the solvent, the inorganic filler, and the additive shown in the following Table 2 was stirred to obtain a photosensitive resin composition 2.

<Preparation of photosensitive resin composition 3>

The ratio of the polymer binder, the unsaturated photopolymerizable compound, the photoinitiator, the heat curing agent, the solvent, the inorganic filler, and the additive shown in the following Table 3 is stirred to obtain a photosensitive resin composition. 3.

<Preparation of photosensitive dry film>

<Example 1>

The photosensitive resin composition 1 was uniformly applied to the first surface of the PET supporting substrate having the gloss, surface roughness, and thickness properties as shown in Table 4, and was dried at 90 ° C using a hot air convection dryer. The coated photosensitive resin composition is dried The drying was carried out for about 5 minutes to form a photosensitive resin layer having a film thickness of 40 μm. Then, on the surface of the photosensitive resin layer not in contact with the support substrate, a PET film modified with a polyfluorinated surface is bonded as a protective film to obtain a photosensitive dry film 1 having the structure as illustrated in FIG. .

<Example 2>

The photosensitive dry film 2 was prepared in the same manner as in Example 1 except that PET support substrates having different gloss and surface roughness properties were used, as shown in Table 4.

<Example 3>

The photosensitive dry film 3 was prepared in the same manner as in Example 1, except that the photosensitive resin composition 2 was used to form a photosensitive resin layer, and PET support substrates having different gloss, surface roughness, and thickness properties were used. As shown in Table 4.

<Example 4>

A photosensitive dry film 4 was prepared in the same manner as in Example 3 except that PET support substrates having different gloss, surface roughness, and thickness properties were used, as shown in Table 4.

<Example 5>

A photosensitive dry film 5 was prepared in the same manner as in Example 1, except that the photosensitive resin composition 3 was used to form a photosensitive resin layer, and PET support substrates having different gloss, surface roughness, and thickness properties were used. As shown in Table 4.

<Example 6>

A photosensitive dry film 6 was prepared in the same manner as in Example 5 except that PET support substrates having different gloss, surface roughness, and thickness properties were used, such as a watch. 4 is shown.

<Example 7>

A photosensitive dry film 7 was prepared in the same manner as in Example 5 except that PET support substrates having different gloss and surface roughness properties were used, as shown in Table 4.

<Example 8>

A photosensitive dry film 8 was prepared in the same manner as in Example 5 except that PET support substrates having different gloss, surface roughness, and thickness properties were used, as shown in Table 4.

<Example 9>

A photosensitive dry film 9 was prepared in the same manner as in Example 5 except that PET support substrates having different gloss, surface roughness, and thickness properties were used, as shown in Table 4.

<Comparative Example 1 and Comparative Example 2>

Comparative photosensitive dry film 1 and comparative photosensitive dry film 2 were prepared in the same manner as in Example 1, except that PET support substrates having different gloss and surface roughness properties were used, as shown in Table 4.

<Comparative Example 3 and Comparative Example 4>

Comparative photosensitive dry film 3 and comparative photosensitive dry film 4 were prepared in the same manner as in Example 3 except that PET support substrates having different gloss, surface roughness, and thickness properties were used, as shown in Table 4.

<Comparative Example 5>

A comparative photosensitive dry film 5 was prepared in the same manner as in Example 5, except PET support substrates having different gloss, surface roughness, and thickness properties were used, as shown in Table 4.

<Preparation of photosensitive development cover film (1)>

The copper surface of the copper foil laminate (trade name: MCL-E-679; Hitachi Chemical Co., Ltd.) for printed wiring boards was processed using a roughening pretreatment liquid CZ-8100 (MEC Co., Ltd.), followed by Pure water is washed and dried. The copper foil laminate is obtained by laminating a copper foil having a thickness of 12 μm on a glass epoxy substrate.

Using the photosensitive dry film 1, the photosensitive dry film 2, the photosensitive dry film 5 to the photosensitive dry film 9, the comparative photosensitive dry film 1, the comparative photosensitive dry film 2, and the comparative photosensitive dry film 5, respectively A photosensitive development cover film is formed on the surface of the copper foil of the pretreated copper foil laminate. First, the photosensitive film of the photosensitive dry film or the comparative dry film is removed, and the photosensitive resin layer and the supporting substrate are bonded to the surface of the copper foil. Then, press-pressing vacuum press (model: MVP-600; Changxing Material Co., Ltd.) was pressed (pressing hot plate temperature: 50 ° C to 60 ° C; vacuuming time: 30 seconds; vacuum pressure: Less than 2 hPa; pressing time: 30 seconds; and pressing pressure: 0.5 MPa to 0.7 MPa), forming a laminated structure including a copper foil laminated plate, a photosensitive resin layer, and a supporting substrate.

After the laminated structure was allowed to stand at room temperature for 0.5 hour, exposure and development were carried out to form a photosensitive development cover film on the surface of the copper foil of the copper foil laminate. First, a 21-step exposure tablet was set, and exposure was performed using a direct image exposure apparatus (model: DXP-3512; ORC MANUFACTURING Co., Ltd.) using an ultrahigh pressure mercury lamp as a light source. After exposure, it was allowed to stand at room temperature for 30 minutes, and then the support substrate was removed. Subsequently, spray development was carried out for 30 seconds to 50 seconds using a 1% sodium carbonate aqueous solution at 30 ° C to remove the unexposed portion of the photosensitive resin layer. The exposure energy of the gloss residual exposure number of the 21-bed exposure grid was 9 to 10 as the sensitivity (unit: mJ/cm ² ) of the photosensitive resin layer. Finally, it was baked in an oven (temperature: 150 ° C to 155 ° C) for 50 minutes to 60 minutes, and then the formed photosensitive development cover film pattern was evaluated, and the results are shown in Table 5 below.

<Preparation of photosensitive development cover film (2)>

The copper surface of the copper foil laminate (trade name: MCL-E-679; Hitachi Chemical Co., Ltd.) for printed wiring boards was treated with a 5% to 10% H ₂ SO ₄ aqueous solution, followed by washing with pure water. After drying. The copper foil laminate is obtained by laminating a copper foil having a thickness of 12 μm on a polyimide substrate.

A photosensitive development film is formed on the surface of the copper foil of the copper foil laminate which has been subjected to the pretreatment by using the photosensitive dry film 3, the photosensitive dry film 4, the comparative photosensitive dry film 3, and the comparative photosensitive dry film 4, respectively. First, the photosensitive film of the photosensitive dry film or the comparative dry film is removed, and the photosensitive resin layer and the supporting substrate are bonded to the surface of the copper foil. Then press using a hot roller press (compression temperature: 60 ° C to 70 ° C; press speed: 0.5 M / min to 1.0 M / min; press pressure: 5 kgf / cm ² to 6 kgf / cm ² ), formed A laminated structure comprising a copper foil laminate, a photosensitive resin layer and a support substrate.

After the laminated structure was allowed to stand at room temperature for 30 minutes or more, exposure and development were carried out to form a photosensitive development cover film on the surface of the copper foil of the copper foil laminate. First, a 21-slot exposure grid was set and exposed using a direct image exposure apparatus using an ultra-high pressure mercury lamp as a light source. The support substrate was removed and baked at a temperature of 90 ° C for 15 minutes. Finally, the unexposed portion of the photosensitive resin layer was removed by spray development with a 1% potassium carbonate aqueous solution at 30 ° C for 44 seconds. The exposure energy of the gloss residual exposure number of the 21-bed exposure grid was 6 to 8 as the sensitivity (unit: mJ/cm ² ) of the photosensitive resin layer. Finally, it was baked in an oven (temperature: 170 ° C to 275 ° C) for 60 minutes to 120 minutes, and then the formed photosensitive development cover film pattern was evaluated, and the results are shown in Table 5 below.

As shown in the results in Table 5, the cover film formed by the photosensitive dry film of the present invention has excellent resolution (90 micrometers or less), and has a low-gloss haze black texture, which is both beautiful and provides line protection. The function.

From the results of Comparative Example 1 and Examples 1 and 2, it is known that if the surface roughness of the first surface of the support substrate is too small (for example, less than 260 nm), and the substrate is supported The roughness of the first surface is too small (for example, less than 110 nm) than the roughness of the second surface, and the obtained cover film does not have a good haze black texture, and the resolution of the pattern formed by the photosensitive resin layer Not good. From the results of Comparative Example 2, Comparative Example 3, and Examples 1 to 4, it can be seen that if the surface roughness of the first surface of the supporting substrate is too small (for example, less than 260 nm), the obtained coating film does not have good fog black. Texture.

From the results of Comparative Example 4 and Examples 3 and 4, it can be seen that if the roughness of the roughness of the first surface of the supporting substrate and the roughness of the second surface is too small (for example, less than 110 nm), the obtained pattern The resolution is not good.

From the results of Comparative Example 5 and Examples 5 to 9, it is known that if the surface roughness of the first surface of the support substrate is too large (for example, more than 1000 nm), and the roughness of the first surface of the support substrate is the same If the difference in roughness between the two surfaces is too large (for example, greater than 850 nm), the resolution of the resulting pattern is not good.

The above embodiments are merely illustrative of the principles of the present invention and its effects, and illustrate the technical features of the present invention, and are not intended to limit the scope of protection of the present invention. Any change or arrangement that can be easily accomplished by anyone familiar with the technology without departing from the technical principles and spirit of the creation is within the scope of this creation. Therefore, the scope of protection of the present invention is as set forth in the appended claims.

1‧‧‧ release layer

2‧‧‧Photosensitive resin layer

4‧‧‧Support substrate

Claims (10)

A photosensitive dry film comprising a support substrate and a photosensitive resin layer on the support substrate, wherein the support substrate comprises a first surface in contact with the photosensitive resin layer and opposite to the first surface a second surface, and the first surface has a non-smooth structure. The photosensitive dry film of claim 1, wherein the first surface of the support substrate has a gloss of less than 15 GU as measured by the ASTM D523 standard method. The photosensitive dry film of claim 1, wherein the first surface has an average roughness (Ra) which is 110 nm to 850 nm higher than the roughness of the second surface. The photosensitive dry film of claim 1, wherein the second surface has a smooth structure. The photosensitive dry film of claim 1, wherein the first surface has an average roughness (Ra) of from 260 nm to 1000 nm. The photosensitive dry film of claim 1, wherein the support substrate has a thickness of from 10 micrometers to 250 micrometers. The photosensitive dry film of claim 1, wherein the support substrate is a polyester film or a polyolefin film. The photosensitive dry film of claim 1, wherein the photosensitive resin layer is formed by drying a photosensitive resin composition on the first surface of the support substrate, and the photosensitive resin composition contains 15% by weight to 80% by weight of the polymer binder, 2% by weight to 65% by weight of the photopolymerizable compound containing an unsaturated group, 0.5% by weight Up to 20% by weight of a photoinitiator. The photosensitive dry film of claim 8, wherein the polymer binder is an acrylic adhesive or a polyimide-based adhesive, and the unsaturated group-containing photopolymerizable compound is an acrylate-based photopolymerizable polymer. Compound. The photosensitive dry film of claim 8, wherein the photosensitive resin composition further contains an additive.