JPH0792673A - Photosensitive resin composition and photosensitive film - Google Patents

Abstract

PURPOSE:To provide a photosensitive resin composition and a photosensitive film without peeling between the photosensitive layer and a support even in the case of conveying the photosensitive laminate in an uncut state and storing it, and having superior various performances. CONSTITUTION:The photosensitive resin composition soluble or swellable in an aqueous solution of alkali comprising 3-20 pts.wt. of an ethylenically unsaturated compound represented by formula in which R<1> is H or methyl; R<2> is H or a 1-3C alkyl; R<3> is a 4-14C alkyl; n is an integer of 13-20; and m is 1, 2, or 3. (B) 15-40 pts.wt. of an ethylenically unsaturated compound other than (A), (C) 50-70 pts.wt. of a polymer having carboxylic groups, [the total content of (A), (B), and (C) is 100 pts.wt.], and (D) 0.05-20 pts.wt. of a photoinitiator, and the photosensitive film using this resin composition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive resin composition, and more particularly to a photosensitive resin composition and a photosensitive film which can be developed and peeled with an alkaline aqueous solution used for preparing a printed circuit board.

[0002]

2. Description of the Related Art A photosensitive resin composition is widely used as a resist used in the production of printed circuit boards, and a photosensitive film obtained by laminating the photosensitive resin composition on a support is also widely used. . These photosensitive films are
The alkali developing type, which removes the uncured portion with an alkaline aqueous solution, is the mainstream.

In this photosensitive film, a photosensitive layer is laminated on a substrate for a printed circuit board which has been polished or treated with chemicals, the laminate is cut into a size corresponding to one printed circuit board, and then a desired negative mask is formed. After exposure through, remove the support,
It is used by a method of forming a resist image on a substrate by developing using an alkaline aqueous solution such as a 0.5 to 3 wt% sodium carbonate aqueous solution.

When cutting a laminate in which a photosensitive film is laminated on a printed circuit board, chips and a photosensitive layer may be brought into an exposure machine, which may interfere with the exposure during pattern exposure. Therefore, it has been considered to expose the laminate as a continuous body without cutting. However, in a commercially available photosensitive film, the adhesive strength between the support and the photosensitive layer is weak, and the air is peeled between the photosensitive layer and the support layer due to the force generated during carrying and stacking of the continuous body. There is a problem that a pattern cannot be formed due to entering and oxygen inhibition.

In order to improve the adhesive strength between the support and the photosensitive layer, there is a method of lowering the viscosity of the photosensitive layer. However, when the photosensitive film is stored in a rolled state, the end part of the roll is rolled. The resin in the photosensitive layer flows out from the above, and a phenomenon called edge fusion occurs in which the adjacent photosensitive layers are connected to each other, and it cannot be put to practical use.

Therefore, it is conceivable to use a compound having a high adhesive force with the polyethylene terephthalate film (PET), but desired properties cannot be obtained in terms of adhesion with copper and the like. For example, in phenoxypolyethoxyethyl acrylate, phenoxypolypropoxyethyl acrylate, etc. described in JP-B-4-22508, when the number of ethoxy groups or propoxy groups is small, the above-mentioned adhesive strength is low, and R ³ When there is no linear alkyl group, the developer resistance is lowered. Also, the polyethoxy group is more PET than the polypropyloxy group.
Adhesion with and tends to be high.

[0007]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, and conveys a continuous film as it is without cutting a laminate in which a photosensitive film is laminated on a printed circuit board. Then, even when stored, a peeling between the photosensitive layer and the support does not occur, and a photosensitive resin composition and a photosensitive film having various excellent properties are provided.

[0008]

The present invention provides (A) an ethylenically unsaturated compound represented by the following general formula (I) in an amount of 3 to 2
0 parts by weight

[Chemical 3] (In the formula, R ¹ represents a hydrogen atom or a methyl group, R ² represents a hydrogen atom or a C _{1 to} C ₄ alkyl group, and R ³ represents a C ₄ to
Represents a C ₁₄ alkyl group, n is an integer of 13 to 20, and m is an integer of 1 to 3) (B) An ethylenically unsaturated compound other than the above (A) is 15
To 40 parts by weight and (C) a polymer compound having a carboxyl group in an amount of 50 to 7
0 parts by weight (however, the total amount of (A), (B) and (C) is 1)
100 parts by weight) and (D) a photoinitiator in a total amount of (A), (B) and (C) of 10
0.05 to 20 parts by weight based on 0 parts by weight,
The present invention relates to a photosensitive resin composition that is soluble or swellable in an alkaline aqueous solution and a photosensitive film obtained by laminating the photosensitive resin composition on a support.

The (A) ethylenically unsaturated compound represented by the general formula (I) used in the present invention has a structure in which 1 to 3 alkyl groups are bonded to a phenoxy group (bonding of alkyl groups If the number (m) is 4 or more, the availability and the developability are deteriorated), and the number of carbon atoms of this alkyl group is 4
~ 14 When the carbon number is 3 or less, the developing solution resistance and the adhesive force to copper decrease, and when it is 15 or more, the developability also decreases. A halogen atom, a nitrogen atom-containing group, an aryl group, an alkylene group or the like may be bonded to the phenoxy group. Examples of this compound include nonylphenoxypolyethoxyethyl (meth) acrylate, butylphenoxypolyethoxyethyl (meth) acrylate, and the like, wherein the number of repeating units of the ethoxy group in which R ² is a hydrogen atom and R ² is methyl. The total number (n) of repeating units of the propyloxy group as a group is 13 to 20 on average, and preferably 14 to 16. If this number is less than 13, the adhesive force between the support such as PET and the photosensitive layer cannot be obtained, and if it exceeds 20, the developing solution resistance of the photosensitive layer deteriorates. The amount of the component (A) used is 3 to 20 parts by weight based on 100 parts by weight of the total amount of (A), (B) and (C), and if less than 3 parts by weight, a support such as PET is used. If the adhesive strength to the photosensitive layer cannot be obtained and the amount exceeds 20 parts by weight, the crosslink density decreases and the film strength of the photosensitive layer decreases.

Examples of the (B) ethylenically unsaturated compound other than the above (A) used in the present invention include, for example, JP-B-5
Photopolymerizable compounds described in JP-A-3-37214, monomers described in JP-A-53-56018, photopolymerizable urethane compounds described in JP-B-59-23723, etc. Is mentioned. Specific examples of the ethylenically unsaturated compound include trimethylolpropane, trimethylolethane, pentaerythritol, dipentaerythritol, 1,6-hexanediol, propylene glycol, tetraethylene glycol, dibromoneopentyl glycol, and lauryl. Examples thereof include acrylic acid esters or methacrylic acid esters of monohydric or polyhydric alcohols such as alcohols. Reaction products of acrylic acid or methacrylic acid with compounds having an epoxy group such as cycloaliphatic epoxy resin, epoxidized novolac resin, bisphenol A-epichlorohydrin type epoxy resin such as bisphenol A-polyethoxyethyl (meth) acrylate Can be used. Among these (B) ethylenically unsaturated compounds, a bisphenol A polyethoxyethyl (meth) acrylate compound represented by the following general formula (II) is preferable from the viewpoint of photocurability, adhesion, etc., and its use The amount is 30 to 80 of the component (B)
It is preferable to set it to be wt%.

[Chemical 4] (In the formula, R ³ represents a hydrogen atom or a methyl group, and p and q are integers selected so that p + q is 6 to 14.) (B) The amount of the ethylenically unsaturated compound used is (A) ,
15 to 4 based on 100 parts by weight of the total amount of (B) and (C)
It is set to 0 parts by weight. If it is less than 15 parts by weight, the curing rate will decrease, and if it exceeds 40 parts by weight, resin leaching from the edges (edge fusion) will occur when the photosensitive laminate is rolled.

As the polymer compound having a carboxyl group (C) used in the present invention, a known polymer compound having thermoplasticity can be used, and there is no particular limitation, but a polymer obtained by vinyl copolymerization can be used. preferable. Examples of vinyl polymerizable monomers used for vinyl copolymerization include methyl methacrylate, butyl methacrylate, ethyl acrylate, styrene, α-methylstyrene, vinyltoluene, 2-hydroxyethyl methacrylate, and 2-hydroxypropyl acrylate. , Acrylic acid, trifluoroethyl methacrylate, tetrafluoropropyl acrylate, methacrylic acid, t-butylaminoethyl methacrylate, 2,3-dibromopropyl methacrylate, 3-chloro-2-hydroxypropyl methacrylate, tetrahydrofurfuryl methacrylate, tribromophenyl Acrylate, acrylamide, acrylonitrile, butadiene, etc. are mentioned. These are used alone or in combination of two or more. The weight average molecular weight of the polymer compound is preferably in the range of 20,000 to 300,000, and preferably 50,000 to 200,000.
The range of 00 is more preferable. Weight average molecular weight is 20,0
When it is less than 00, the fluidity of the photosensitive laminate is large, the storage stability is poor, and the development resistance tends to be low. On the other hand, if it exceeds 300,000, the compatibility with other components tends to deteriorate. The amount of the polymer compound (C) having a carboxyl group is 50 to 50 parts by weight based on 100 parts by weight of the total amount of (A), (B) and (C) from the viewpoint of viscosity and photocurability of the photosensitive resin composition. 70 parts by weight. From the viewpoint of developing the obtained photosensitive resin composition with an alkaline aqueous solution, the acid value of the polymer compound (C) having a carboxyl group is preferably 50 to 300, and more preferably 100 to 200. .

The photoinitiator (D) used in the present invention is not particularly limited, but for example, 2,4,5-triarylimidazole dimer and 2-mercaptobenzoquinazole, leuco crystal violet, Tris. Examples include combinations with (4-diethylamino-2-methylphenyl) methane and the like. Further, although it does not have photoinitiating property by itself, it is possible to use an additive which becomes a photopolymerization initiator system having better photoinitiating performance as a whole when used in combination with the above-mentioned substances. Examples of such additives include tertiary amines such as triethanolamine for benzophenone. (D) The amount of the photoinitiator used is (A), from the viewpoint of photocurability.
0.05 based on 100 parts by weight of the total of (B) and (C)
~ 20 parts by weight.

The photosensitive resin composition may further be mixed with an adhesion improver, a thermal polymerization inhibitor, a dye, a pigment, a plasticizer, a flame retardant, a fine particulate filler, a coatability improver, and the like. These selections are made under the same considerations as those for ordinary photosensitive resin compositions.

The fluidity of the photosensitive layer, which is a layer of the photosensitive resin composition, is preferably 300 μm or less. If the fluidity is too small, the laminating property tends to deteriorate, and if it is too large, edge fusion tends to occur. The lower limit of fluidity is usually 150 μm. What is liquidity?
Using a 12 mm-thick layer of a photosensitive layer, which is a layer of a photosensitive resin composition, punched out into a circle with a diameter of 15 mm, a William Plastometer (manufactured by Kamijima Seisakusho) installed in a constant temperature bath at 30 ° C was used. It is the value measured using. The sample is left on the measuring table of the plast maker (atmosphere of 30 ° C) for 10 minutes, and then a load of 5 kg is applied to it.
The film thickness (A) after 0 seconds and the film thickness (B) after 900 seconds are measured, and the value (μm) of (A)-(B) is taken as the fluidity.

As the support used in the present invention, a polymer film, for example, a film made of polyethylene terephthalate, polypropylene, polyethylene or the like is used, and a polyethylene terephthalate film is preferable. These polymer films must not be of a material that makes them impossible to remove, as they must be removable from the photosensitive layer later. The adhesive strength of the photosensitive layer, which is not removed during carrying after lamination used in the present invention, is preferably 10 to 100 g / cm (using a 180 ° peel rheometer) in view of the adhesiveness of the support. The thickness of these polymer films is usually 5 to 100 μm, preferably 10 to
It is 30 μm. One of these polymer films may be laminated on both sides of the photosensitive layer as a support film for the photosensitive layer and the other as a protective film for the photosensitive layer.

In producing the photosensitive film, first, the photosensitive resin composition containing the components (A) to (D) is uniformly dissolved in a solvent. The solvent may be a solvent that dissolves the photosensitive resin composition, for example, acetone-based solvents such as methyl ethyl ketone and methyl isobutyl ketone, ether-based solvents such as methyl cellosolve and ethyl cellosolve, chlorinated dichloromethane and chloroform. Hydrocarbon-based solvents, alcohol-based solvents such as methyl alcohol, ethyl alcohol and the like are used. These solvents may be used alone or in combination of two or more.

Then, the photosensitive resin composition in the form of a solution is uniformly applied on the polymer film as the support film layer, and then the solvent is removed by heating and / or blowing with hot air to form a dry film. The thickness of the dry film is not particularly limited and is usually 10 to 100 μm, preferably 20 to 6
It is set to 0 μm. The photosensitive film of the present invention comprising two layers of the photosensitive layer and the polymer film thus obtained is stored as it is or on the other surface of the photosensitive layer, the protective film is further wound into a roll and stored. It

In producing a photoresist image using the photosensitive film of the present invention, when the protective film is present, after removing the protective film, the photosensitive layer is heated and pressed onto the substrate. To stack.
The surface to be laminated is usually a metal surface, but is not particularly limited. Heating and pressure bonding of the photosensitive layer are usually 90 to 130 ° C.,
The pressure is 3 kgf / cm ² , but these conditions are not particularly limited.

When the photosensitive film of the present invention is used, it is not necessary to preheat the substrate beforehand if the photosensitive layer is heated as described above. Needless to say, the substrate may be preheated to further improve the stackability.

The photosensitive layer thus laminated is
It is then imagewise exposed to actinic light using a negative or positive film. At this time, when the polymer film existing on the photosensitive layer is transparent, it may be exposed as it is, and when it is opaque, it is of course necessary to remove it. From the viewpoint of protecting the photosensitive layer, it is preferable that the polymer film is transparent, and the polymer film is allowed to remain and exposed through it. As the active light, light generated from a known active light source such as carbon arc, mercury vapor arc, xenon arc, or the like is used. The sensitivity of the photoinitiator contained in the photosensitive layer is usually maximum in the UV region, in which case the actinic light source should be one which emits UV radiation effectively. Of course, when the photoinitiator is one that is sensitive to visible light, for example, 9,10-phenanthrenequinone, visible light is used as the active light, and the light source other than those described above is photographed. Flood light bulbs and sun lamps are also used.

After the exposure, if a polymer film is present on the photosensitive layer after exposure, it is removed and then an alkaline aqueous solution is used, for example, publicly known methods such as spraying, rocking dipping, brushing and scrubbing. By the method, the unexposed portion is removed and development is performed. Examples of the base of the alkaline aqueous solution include alkali hydroxides such as lithium, sodium or potassium hydroxides, alkali carbonates such as lithium, sodium or potassium carbonates or bicarbonates, alkali metals such as potassium phosphate and sodium phosphate. Phosphates, alkali metal pyrophosphates such as sodium pyrophosphate, potassium pyrophosphate and the like are used, and an aqueous solution of sodium carbonate is particularly preferable. The pH of the aqueous alkaline solution used for development is preferably between 9 and 11, and the temperature is adjusted according to the developability of the photosensitive layer. A surface active agent, a defoaming agent, and a small amount of an organic solvent for accelerating the development may be mixed in the alkaline aqueous solution.

When manufacturing a printed wiring board, the exposed surface of the substrate is treated by a known method such as etching or plating using the developed photoresist image as a mask. Next, the photoresist image is usually stripped with an aqueous solution having a stronger alkaline property than the alkaline solution used for the development. As the strong alkaline aqueous solution, for example, a 1 to 5 wt% sodium hydroxide aqueous solution or the like is used.

[0023]

EXAMPLES Next, the present invention will be described in more detail by way of examples. Unless otherwise specified, "%" in the following examples means "% by weight". Example 1 A solution (solution A) having the composition shown in Table 1 and Table 2 was uniformly applied on a polyethylene terephthalate film (PET) having a thickness of 25 μm by using the apparatus shown in FIG. 1, and the hot air convection method at 100 ° C. was used. The solvent was removed by drying in a dryer 7 for about 3 minutes. In FIG. 1, 1 is a polyethylene terephthalate film payout roll, 2, 3, 4, 9 and 10 are rolls, 5 is a knife, 6 is a solution of a photosensitive resin composition, 8 is a polyethylene film payout roll, and 11 is a photosensitive film. It is a take-up roll. The thickness of the photosensitive layer after drying is
It was about 25 μm.

[0024]

[Table 1]

[Table 2]

Separately, the copper surface of a printed wiring board substrate (trade name: MCL-E-61, manufactured by Hitachi Chemical Co., Ltd.), which is a glass epoxy material in which copper plates are laminated on both sides, is polished with a cleanser, washed with water, and blown with air. Dried in. This substrate (23 ℃)
Laminating machine manufactured by Hitachi Chemical Co., Ltd. (Model HLM-
1500) using a lamination temperature of 110 ° C. and a lamination pressure of 3
The photosensitive film was manufactured at kg / cm ² . Immediately after the production, the photosensitive layer was pulled by hand, but the photosensitive layer adhered well to the substrate and did not peel off.

Next, the above film was cut into a width of 2 cm, and the adhesive force between the polyethylene terephthalate film and the photosensitive layer was measured using a rheator (Fudo Kogyo KK). As a result, it showed a strength of 80 g / cm. Further, when two substrates were laminated and folded, no peeling of PET was observed. Further, when the above photosensitive film having a length of 150 m was wound into a roll and tested for storage stability, no leaching of the photosensitive layer was observed for 3 months, showing good stability.

Then, the obtained sample was mixed with a Stouffer
Exposure was performed for 20 seconds from a distance of 90 cm to a high pressure mercury lamp of 3 kW using a 1-step step tablet and a negative of a linear line of 100 μm.

The development was carried out by removing the polyethylene terephthalate film and then spraying an aqueous 1% sodium carbonate solution at 30 ° C. for 60 seconds (the unexposed portion was completely removed by spraying for 30 seconds, and further 30 seconds).
Sprayed for a second). The 100 μm linear lines are in close contact with each other. As a result of observing this resist image with an electron microscope at a magnification of 400 times, the resist has no creases or cavities and has a good shape, and the number of remaining step tablets is 8 steps. showed that.

Next, a cupric chloride etching solution (an aqueous solution containing 200 g / liter of cupric chloride and 200 g / liter of hydrochloric acid) is heated to 50 ° C. and sprayed at 2.5 kgf / cm ² by a spray type etching machine. Etching was performed by pressure.
When this sample piece was stripped with a 2% sodium hydroxide stripping solution at 50 ° C., a 100 μm wide resist line was 3 cm.
It was peeled off from the substrate while being subdivided into the lengths of, and showed good peelability. Furthermore, the linearity of the copper line was good.

The results are summarized in Table 3. Examples 2 to 4 and Comparative Examples 1 to 2 Using the ethylenically unsaturated compound shown in Example 1 as the compound shown in Table 3, the same test as in Example 1 was conducted, and the results are shown in Table 3.
It was shown to.

[0031]

[Table 3]

As is apparent from Table 3, the photosensitive resin composition of the present invention and the photosensitive film using the same showed excellent adhesiveness to a support and etching resistant resist shape.

[0033]

EFFECTS OF THE INVENTION According to the photosensitive resin composition of the present invention and the photosensitive film using the same, good adhesiveness of the resist to the support, etching resistance, and resist shape can be obtained, and it is possible to handle the substrate. It is possible to prevent air obstruction during exposure due to peeling of the resist and the support.

[Brief description of drawings]

FIG. 1 is a system diagram of a photosensitive film manufacturing apparatus used in Examples.

[Explanation of symbols]

1 Polyethylene terephthalate film feeding roll 2, 3, 4, 9, 10 roll 5 Knife 6 Solution of photosensitive resin composition 7 Dryer 8 Polyethylene film feeding roll 11 Photosensitive film winding roll

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location G03F 7/038 H01L 21/027 H05K 3/00 F

Claims (3)

[Claims] (A) 3 to 20 parts by weight of an ethylenically unsaturated compound represented by the following general formula (I): (In the formula, R ¹ represents a hydrogen atom or a methyl group, R ² represents a hydrogen atom or a C _{1 to} C ₄ alkyl group, and R ³ represents a C ₄ to
Represents a C ₁₄ alkyl group, n is an integer of 13 to 20, and m is an integer of 1 to 3) (B) An ethylenically unsaturated compound other than the above (A) is 15
To 40 parts by weight and (C) a polymer compound having a carboxyl group in an amount of 50 to 7
0 parts by weight (however, the total amount of (A), (B) and (C) is 1)
100 parts by weight) and (D) a photoinitiator in a total amount of (A), (B) and (C) of 10
0.05 to 20 parts by weight based on 0 parts by weight,
A photosensitive resin composition that is soluble or swellable in an alkaline aqueous solution. 2. The (B) ethylenically unsaturated compound contains a bisphenol A polyethoxyethyl (meth) acrylate compound represented by the following general formula (II):
The photosensitive resin composition described. [Chemical 2] (In the formula, R ³ represents a hydrogen atom or a methyl group, and p and q are integers selected so that p + q is 6 to 14.) 3. A photosensitive film obtained by laminating the photosensitive resin composition according to claim 1 or 2 on a support.