JP2000356852A - Photosensitive resin laminated body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the adhesion of a resist to the top of a wafer and to improve plating resistance in a conductor plating step by incorporating a specified polymer, a specified polymerizable monomer and p-aminophenyl ketone into a photosensitive resin layer. SOLUTION: The photosensitive resin laminated body comprises a substrate and a photosensitive resin layer containing 20-90 wt.% polymer having a carboxyl content of 100-600 (expressed in terms of acid equivalent) and a weight average molecular weight of 20,000-500,000, 10-60 wt.% one or more polymerizable monomers including at least a compound of the formula and 0.001-0.1 wt.% at least one p-aminophenyl ketone. In the formula, X is H, methyl or hydroxy A is a residue of a copolymer of CH2CH(CH3)O and CH2CH2O, (n) is an integer of 0-5 and R is H or methyl. A compound having one (meth) acrylic ester group called a monofunctional monomer is used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive resin laminate, and more particularly to a photosensitive resin laminate suitable for manufacturing a CSP (Chip Size Package).

[0002]

2. Description of the Related Art A CSP is a component in which an LSI chip is packaged, and is generally a package having a size equal to or slightly larger than the size of an LSI chip. . The CSP has a BGA (Ball Grid) depending on the package type.
Array) type, LGA (Land Grid Array) type,
SON (Small Outline Non-leaded) type, etc.

Conventionally, an LSI chip is packaged in a CSP by cutting an LSI manufactured on a wafer into individual chips, and then bonding the LSI chip to a wiring board having external terminals by wire bonding, soldering, ultrasonic bonding, or the like. And then sealing or underfilling with an organic resin if necessary. In recent years, a plurality of LSIs formed on a silicon wafer are collectively formed with wiring and external terminals before cutting, and if necessary, are sealed with an organic resin to form a CSP or BG.
A method of cutting individual parts after the parts such as A are started to be adopted. Parts made by this method are commonly referred to as wafer level CSPs.

In the process of producing a wafer-level CSP, wiring for connecting an LSI chip terminal to an external terminal is required, and is often formed by plating a conductor. More specifically, after applying and drying a liquid resist on a wafer on which a metal layer has been applied, an actinic ray is exposed through a wiring pattern mask, and the resist is developed and removed, so that only a portion where conductor wiring is to be formed is opened. Then, electrolytic metal plating is performed thereon to form necessary wiring.

[0005] Examples of the wiring include a linear wiring and a columnar wiring in which via holes are filled with copper. In particular, regarding the columnar wiring, it is required that the plating thickness be as large as 50 μm to 200 μm. When forming the wiring, a liquid resist is used as a resist. However, if the liquid resist does not have a desired thickness by a single application, a plurality of applications are required and the number of steps increases. was there. Also,
The repetition of coating and drying a plurality of times deteriorates the final uniformity of the resist thickness, and the coating method for making the resist uniform becomes complicated in operation.

In addition, when the plating thickness is as thick as 100 to 200 μm, the time required for electric conductor plating is prolonged, so that the resist partially peels off from the substrate while being immersed in the plating solution, and as a result, the plating And it was easy to be defective.

[0007]

SUMMARY OF THE INVENTION The present invention relates to the aforementioned C
An object of the present invention is to provide a photosensitive resin laminate that can solve the problems in the production of SP.

[0008]

The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, as a resist for forming a wiring by plating, a specific polymerizable monomer and p-type as a photoinitiator were used. By using a photosensitive resin laminate having a layer of a photosensitive resin composition containing aminophenyl ketone, the adhesion of the resist on the wafer is improved, and the plating resistance in the conductor plating step is significantly improved. I found that. In addition, it has been found that the combination of a specific polymerizable monomer, in addition to the performance improvement, also improves the peelability of the cured resist.

That is, the first aspect of the present invention comprises a support and a photosensitive resin layer, wherein the photosensitive resin layer has (1) a carboxyl group content of 100 to 600 in acid equivalent and a weight average molecular weight of 20,000. -500,000 polymers: 20-90% by weight, (2) one or more polymerizable monomers containing at least a compound represented by the following formula (1): 10-60% by weight,

[0010]

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(Where X represents a hydrogen atom, a methyl group or a hydroxyl group. A represents CH ₂ CH (CH ₃ ) O and CH ₂
Represents a copolymer residue of CH ₂ O, and n represents an integer of 0 to 5. R represents a hydrogen atom or a methyl group. And (3) at least one p-aminophenyl ketone:
Provided is a photosensitive resin laminate containing 0.001 to 0.1% by weight. Furthermore, in order to improve the releasability, a compound having one (meth) acrylate group (a compound called a monofunctional monomer) is used in addition to the polymerizable monomer used in the first invention. To provide a photosensitive resin laminate. (This is referred to as a second invention.) The photosensitive resin laminate of the present invention comprises a support layer and a photosensitive resin composition. In general, a photosensitive resin composition is laminated on a support film, and in many cases, Further, a protective film is laminated on the composition.

In the present invention, the amount of the carboxyl group contained in the polymer (1), which is a component of the photosensitive resin layer, must be 100 to 600 in terms of acid equivalent, and is 300 to 40.
0 is preferred. Here, the acid equivalent refers to the weight of a polymer having one equivalent of a carboxyl group therein. The measurement of the acid equivalent is performed by potentiometric titration with 0.1N sodium hydroxide. When the acid equivalent is 100 or less, the compatibility with the coating solvent or the monomer is reduced, and when the acid equivalent is 600 or more, the developability and the peelability are reduced.

The weight average molecular weight of the polymer must be 20,000 to 500,000, more preferably 40,000 to 200,000. The molecular weight is measured by gel permeation chromatography (GPC) using a standard polystyrene calibration curve. If it is 500,000 or more, the developability is reduced, and if it is 20,000 or less, it becomes difficult to maintain a uniform thickness of the photosensitive resin layer when used in a photosensitive resin laminate. The polymer is obtained by copolymerizing one or more of each of the following two types of monomers. The first monomer is a carboxylic acid having one polymerizable unsaturated group such as a carbon-carbon double bond in the molecule. For example, (meth) acrylic acid, fumaric acid, cinnamic acid, crotonic acid, itaconic acid, maleic acid half ester and the like. Second
Is a non-acidic monomer having a polymerizable unsaturated group such as a carbon-carbon double bond in the molecule, and has the developability of the photosensitive resin layer, the resistance in the etching step, and the flexibility of the cured film. It is selected to maintain various properties such as sex. For example, (meta)
Methyl acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate,
Alkyl (meth) acrylates such as 2-ethylhexyl (meth) acrylate and 2-hydroxyethyl (meth) acrylate, benzyl (meth) acrylate, esters of vinyl alcohol such as vinyl acetate, styrene or polymerizable Examples include styrene derivatives and (meth) acrylonitrile.

The component (2) of the photosensitive resin layer of the present invention.
It is necessary to include at least a compound represented by the following general formula (1).

[0015]

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(Where X represents a hydrogen atom, a methyl group or a hydroxyl group. A represents CH ₂ CH (CH ₃ ) O and CH ₂
Represents a copolymer residue of CH ₂ O, and n represents an integer of 0 to 5. R represents a hydrogen atom or a methyl group. Specific examples of such a compound include glycerin propylene oxide-added tri (meth) acrylate, glycerin ethylene oxide-added tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, and trimethylolpropane propylene oxide-added tri (meth) acrylate. Acrylate, trimethylolpropane ethylene oxide-added tri (meth) acrylate, trimethylolpropanepropylene oxide ethylene oxide-added tri (meth) acrylate, pentaerythritol tri (meth) acrylate, and the like can be given.

According to the second invention, the polymerizable monomer (2), which is a component of the photosensitive resin layer, is a compound represented by the following general formula (1):

[0018]

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(Where X represents a hydrogen atom, a methyl group or a hydroxyl group. A represents CH ₂ CH (CH ₃ ) O and CH ₂
Represents a copolymer residue of CH ₂ O, and n represents an integer of 0 to 5. R represents a hydrogen atom or a methyl group. ) And a compound having one (meth) acrylate group. Specific examples of such a compound having one (meth) acrylate group include 2-
Hydroxy-3-phenoxypropyl acrylate (the following compound),

[0020]

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Phenoxyhexaethylene glycol acrylate (the following compound),

[0022]

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Β-hydroxypropyl-β ′-(acroyloxy) propyl phthalate (the following compound),

[0024]

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4-N-octylphenoxypentaethylene glycol tripropylene glycol acrylate (the following compound)

[0026]

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And the like. The polymerizable monomer used in the present invention may include an unsaturated compound having at least one terminal ethylenically unsaturated group other than those described above. Examples of such compounds include 1,4-tetramethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,4-cyclohexanediol di (meth) acrylate, and octapropylene glycol di ( (Meth) acrylate, 2-di (p-hydroxyphenyl) propane di (meth) acrylate, glycerol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, bisphenol A
Diglycidyl ether di (meth) acrylate, ethylene oxide-modified (meth) acrylate of isocyanuric acid, diallyl phthalate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, bis (polyethylene glycol (meth) acrylate) polypropylene glycol , Etc. Further, examples thereof include urethanization products of a polyvalent isocyanate compound such as hexamethylene diisocyanate and tolylene diisocyanate with a hydroxy acrylate compound such as 2-hydroxypropyl (meth) acrylate.

The amount of the polymerizable monomer contained in the photosensitive resin layer is in the range of 10 to 60% by weight, preferably 20 to 50% by weight. In the photosensitive resin layer of the present invention,
It is necessary to include at least one p-aminophenyl ketone as a photoinitiator. The amount of p-aminophenyl ketone contained in the photosensitive resin layer is 0.001 to
0.1% by weight, preferably from 0.01 to 0.1% by weight.
08% by weight. As a specific example, p-aminophenylketone is preferably, for example, p-aminophenylketone.
Aminobenzophenone, p-butylaminophenone, p
-Dimethylaminoacetophenone, p-dimethylaminobenzophenone, p, p'-bis (ethylamino) benzophenone, p, p'-bis (dimethylamino) benzophenone [Michler's ketone], p, p'-bis (diethylamino) benzophenone, p , P'-bis (dibutylamino) benzophenone and the like are used.

More preferably, the structure of p-aminophenylketone is p, p'-bis (dimethylamino) benzophenone or p, p'-bis (diethylamino) benzophenone. The other initiator contained in the photosensitive resin layer of the present invention is not particularly limited, and any known compounds can be used. As a specific example,
Benzyl dimethyl ketal, benzyl diethyl ketal, benzyl dipropyl ketal, benzyl diphenyl ketal, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin phenyl ether, benzoin phenyl ether, 2,4,5-triarylimidazolyl dimer, benzophenone, 9- Acridines such as phenylacridine, α, α-dimethoxy-α-morpholino-methylthiophenylacetophenone, 2,4,6-
Trimethylbenzoylphosphonoxide, phenylglycine, 2-benzyl-2-dimethylamino-1- (4
-Morpholinophenyl) butanone-1, thioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2,4-diisopropylthioxanthone, 2-fluorothioxanthone, 4-fluoro Thioxanthone, 2-chlorothioxanthone, 4-chlorothioxanthone, 1-chloro-4-
Propoxythioxanthone, p-dimethylbenzoic acid, p
-Diethylbenzoic acid and p-diisopropylbenzoic acid and esters thereof with the following alcohols can be used. Examples of the alcohol include methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, butyl alcohol, isobutyl alcohol, sec-butyl alcohol, tert-butyl alcohol, n-amyl alcohol, isoamyl alcohol, hexyl alcohol, and octyl alcohol. Further, 1-phenyl-1,2-propanedione-2
There are oxime esters such as -O-benzoyl oxime and ethyl 2- (O-benzoylcarbonyl) -oxime 2,3-dioxo-3-phenylpropionate.

In order to improve the thermal stability and storage stability of the photosensitive resin used in the present invention, it is preferable that the photosensitive resin layer contains a radical polymerization inhibitor. For example, p-methoxyphenol, hydroquinone, pyrogallol, naphthylamine, tert-butylcatechol, cuprous chloride, 2,6-di-tert-butyl-p-
Cresol, 2,2'-methylenebis (4-ethyl-6
-Tert-butylphenol) and 2,2'-methylenebis (4-methyl-6-tert-butylphenol).

The photosensitive resin layer of the present invention may contain coloring substances such as dyes and pigments. For example, fuchsin, phthalocyanine green, auramine base, chalcoxide green S, paramagenta, crystal violet, methyl orange, Nile blue 2B, Victoria blue, malachite green, basic blue 20, diamond green, and the like. Further, a coloring dye which develops color by light irradiation may be contained. As a color-forming dye, a combination of a leuco dye and a halogen compound is well known. Examples of the leuco dye include tris (4-dimethylamino-2-methylphenyl) methane [leuco crystal violet] and tris (4-dimethylamino-2-methylphenyl).
Methylphenyl) methane [leucomalachite green]
And the like. On the other hand, as the halogen compound, amyl bromide, isoamyl bromide, isobutylene bromide, ethylene bromide, diphenylmethyl bromide, benzal bromide, methylene bromide, tribromomethylphenylsulfone, carbon tetrabromide,
Tris (2,3-dibromopropyl) phosphate, trichloroacetamide, amyl iodide, isobutyl iodide, 1,1,1-trichloro-2,2-bis (p-chlorophenyl) ethane, hexachloroethane and the like.

Further, the photosensitive resin layer of the present invention may contain additives such as a plasticizer, if necessary. For example, phthalic acid esters such as diethyl phthalate, o-toluenesulfonic acid amide, p-toluenesulfonic acid amide, tributyl citrate, triethyl citrate, triethyl acetyl citrate, tri-n-propyl acetyl citrate, triacetyl citrate -N-butyl, polypropylene glycol and the like can be exemplified.

The thickness of the photosensitive resin layer of the present invention is adjusted according to the required thickness of the wiring. It is 50 to 250 μm, preferably 80 to 200 μm, and more preferably 100 to 150 μm. As the support used in the present invention, a polymer film having high transparency to ultraviolet light is used. For example, polyethylene terephthalate film, polyethylene naphthalate film, polyvinyl alcohol film, polyvinyl chloride film, vinyl chloride copolymer film, polyvinylidene chloride film, vinylidene chloride copolymer film, polymethyl methacrylate copolymer film, polystyrene Examples include a film, a polyacrylonitrile film, a styrene copolymer film, a polyamide film, and a cellulose derivative film. These films may be stretched if necessary.

When a protective film is provided, a film is selected which has a property that the adhesion between the protective film and the photosensitive resin layer is smaller than the adhesion between the support and the photosensitive resin layer. For example, a polyerylene film, a polypropylene film and the like can be mentioned. The photosensitive resin laminate of the present invention is used as follows in CSP production. First, if there is a protective film, the protective film is peeled off from the photosensitive resin laminate, and then the base and the photosensitive resin laminate are thermocompression-bonded (laminated) with a pair of heated rolls. A resist film is formed on the material surface. Examples of the thermocompression bonding device (hereinafter, referred to as a laminator) used here include a multi-stage laminator having two or more pairs of heating rolls and a so-called vacuum laminator in which the atmosphere in the roll section is reduced. The temperature of the heating roll at this time is 40 to 160 ° C, preferably 60 to 120 ° C.

The substrate can be applied to individual LSI chips, but a silicon wafer is more preferable.
In general, the surface of a silicon wafer is protected by an organic resin except for the chip terminals, and a base metal layer is often provided on the entire surface by a method such as sputtering for plating. After lamination, the photosensitive resin laminate is exposed to actinic radiation through a mask formed so as to obtain a desired wiring, with or without the support. As actinic radiation, X-rays, electron beams, ultraviolet rays, visible rays, and the like can be used.
Those having a wavelength of 0 nm are preferred. Further, the portion (photosensitive resin) exposed to the actinic radiation is cured.

As an exposure apparatus, a scattering exposure apparatus using a super-high pressure mercury lamp as a light source, a parallel exposure apparatus and the like are used. Also, L
A mask aligner and a stepper, which are common in the manufacture of SI, can also be used. Exposure with ultraviolet light monochromatized by a filter is also possible. Further, a step of heating the wafer immediately after exposure (PEB; Post Exposure Bake) may be performed. The PEB process improves the adhesion of the cured resist to the wafer. The heating temperature is preferably 50 to 100 ° C., and the heating time is preferably 30 seconds to 10 minutes.

The exposed resist is developed with an inorganic or organic alkaline solution. As a result, the unexposed portions are dissolved and removed, leaving the cured resist only in the exposed portions. Examples of the developer used here include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, inorganic alkalis such as aqueous ammonia, primary amines such as ethylamine and n-propylamine, and diethylamine. , Secondary amines such as di-n-propylamine, and tertiary amines such as triethylamine and methyldiethylamine.
Aqueous solutions of amines, alcoholamines such as dimethylethanolamine and triethanolamine, and alkalis such as quaternary ammonium salts such as tetramethylammonium hydroxide and tetraethylammonium hydroxide can be used. When trace amounts of inorganic alkali ions (sodium ions, potassium ions) remaining in the wafer affect the performance of the CSP, it is preferable to use an organic alkali liquid. Development methods include spray, paddle, dipping,
A method such as ultrasonic waves is possible.

By performing electrolytic metal plating on this, a metal having a desired thickness is formed in a portion where there is no hardened resist. Examples of the metal include copper, nickel, chromium, gold, and solder, and particularly, copper plating is frequently used.
A hardened resist equivalent or thicker for the desired plating thickness is required. Since the thickness of the photosensitive resin layer is substantially equal to the thickness of the cured resist after exposure and development, a photosensitive resin laminate having a photosensitive resin laminate equivalent to or thicker than the plating thickness is used.

After forming the conductor wiring as described above,
The cured resist is peeled off with an inorganic or organic alkaline liquid. Generally, it is more alkaline than a developing solution, and is peeled off at a high solution temperature. Examples of the stripping solution used here include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia; primary amines such as ethylamine and n-propylamine; and diethylamine. , Di-n
Secondary amines such as -propylamine, tertiary amines such as triethylamine and methyldiethylamine, alcoholamines such as 2-aminoethanol, dimethylethanolamine and triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide and the like And an aqueous solution containing an appropriate amount of an organic solvent such as methanol, ethanol, dimethylsulfoxide, N-methylpyrrolidone, dimethylformamide and the like. When trace amounts of inorganic alkali ions (sodium ions, potassium ions) remaining in the wafer affect the performance of the CSP, it is preferable to use an organic alkali liquid. As a peeling method, a method such as spraying, paddle, immersion, and ultrasonic wave can be used.

After the cured resist is removed, the underlying metal layer on the wafer is removed by flash etching, plasma etching, reactive ion etching, or the like, leaving only the necessary wiring. Further, a CSP is manufactured by sealing with an organic resin as needed. CS on wafer
When an aggregate of P is produced, it is cut into individual CSPs by dicing.

[0041]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail by way of examples. The characteristic evaluation in the examples was measured by the following method. 1) Resolution evaluation A A mask in which five 80 μm-width line portions and 80 μm-width space portions were alternately arranged on a wafer on which a photosensitive resin laminate was laminated was placed, and a parallel light exposure machine HMW- manufactured by Oak Corporation was used. Exposure was performed at 801 at 200 mJ / cm ² . After peeling off the support, 1% aqueous sodium carbonate solution at 30 ° C.
By spraying for 20 seconds, the photosensitive resin layer in the unexposed portion was removed by development to form five resist patterns arranged side by side. The case where five resist lines were independently formed was evaluated as ○, and the case where some of the five resist lines were connected or peeled off from the wafer surface was evaluated as x. 2) Resolution evaluation B A mask in which five 80 μm-width line portions and 80 μm-width space portions are alternately arranged on a wafer on which a photosensitive resin laminate is laminated, and the mask is aligned with a mask aligner PLA-501F manufactured by Canon Inc. Exposure was for 11 seconds. When the illuminance of the exposure machine was measured, it was 6.3 mW / cm ² , and the calculated exposure was 70 mJ / cm ² . Immediately after the exposure, the wafer was placed in an oven at 80 ° C. and baked for 2 minutes after the exposure. After peeling off the support, 2.38% at room temperature
Paddle development was performed using an aqueous solution of tetramethylammonium hydroxide. Total development time of paddle development is 240
Seconds. Develop and remove the unexposed photosensitive resin layer,
Five resist patterns arranged side by side were formed. If 5 resist lines are independently formed,
The case where a part of the resist line of the book was connected or the resist line was peeled off from the wafer surface was evaluated as x.

3) Evaluation of plating hole The wafer after peeling was observed with an optical microscope and an SEM (scanning electron microscope) to examine the state of the plating hole. The following ranking was used for the judgment.・ ・ ・: No plating burrs at all め っ き: Plating burrs are less than 5 μm ・ ・ ・: Plating burrs are 5 μm or more 4) Evaluation of peelability of cured resist 300 μm dots (diameter of 150 μm in diameter (impermeable to light))
100 rows vertically and 100 rows horizontally (total number of dots: 100
00) A mask having an arranged pattern was placed on a wafer on which a photosensitive resin laminate was laminated, and exposed to a mask aligner PLA-501F manufactured by Canon Inc. for 11 seconds. After peeling off the support, paddle development was carried out at room temperature using a 2.38% aqueous solution of tetramethylammonium hydroxide to form a circular hole of about 150 μmφ. The total development time for paddle development was 240 seconds. This wafer was subjected to electrolytic copper plating in a copper sulfate plating solution for 90 minutes to form a columnar copper wiring. The current density was adjusted to be 5 A / dm2. The height of the copper plating was 100 μm. The wafer after plating was immersed in an alkaline stripping solution at 50 ° C. for 10 minutes to strip the resist. As the alkali stripping solution, a 10% aqueous solution of a film strip 500 manufactured by Meltex Co. was used. The wafer after peeling was observed and evaluated according to the following rank.・ ・ ・: No peeling residue was left on the wafer. △ ・ ・ ・ Ratio of peeling residue around columnar copper wiring
Less than 10% as area. × ・ ・ ・ Ratio of peeling residue around columnar copper wiring
10% or more as area.

[0043]

EXAMPLE 1 60 parts by weight of a polymer having a weight average molecular weight of 200,000 (methyl methacrylate / methacrylic acid / ethyl acrylate = 55/25/20 wt%), and 30 parts of trimethylolpropane triacrylate as a polymerizable monomer.
Parts by weight, 5 parts by weight of 2,4,5-triarylimidazolyl dimer as photoinitiator, 0.05 parts by weight of p, p'-bis (dimethylamino) benzophenone and 100 parts by weight of methyl ethyl ketone as a solvent The dissolved liquid is applied to a support (a 16 μm-thick polyethylene terephthalate film) using a bar coater, dried, and covered with a protective film (a 23 μm-thick polyethylene film) to form a photosensitive resin laminate (a photosensitive resin layer). (Thickness: 100 μm). <Evaluation 1> A chromium layer having a thickness of 2000 angstroms was formed on a 5-inch silicon wafer by a sputtering apparatus manufactured by Anelva, and a copper layer having a thickness of 2000 angstroms was further formed.

The photosensitive resin laminate prepared above was laminated with a laminator AL-70 manufactured by Asahi Kasei so that the surface of the photosensitive resin layer was in close contact with the silicon wafer while peeling off the protective film. Lamination was performed at a roll temperature of 100 ° C., a pressure of 3 kg / cm ² by air pressure, and a speed of 1.5 m / min. A mask was placed on the wafer on which the photosensitive resin laminate was laminated, and the wafer was exposed to 200 mJ / cm ² using a parallel light exposure machine HMW-801 manufactured by Oak.

After the support was peeled off, a 1% aqueous solution of sodium carbonate at 30 ° C. was sprayed for 120 seconds, and the unexposed portion of the photosensitive resin layer was removed by development to form a resist pattern. The result of the resolution evaluation A was ○. The wafer on which the resist is formed is degreased by immersing the wafer in an acidic cleaner (FRTX manufactured by Atotech Japan) at 30 ° C. for 3 minutes, and then electrolyzed in a copper sulfate plating solution (Copper Glyme 125 manufactured by Meltex Corporation) for 6 hours. Copper plated. The current density was adjusted to be 2 A / dm ² . The height of the copper plating was 90 μm. After the plating, the wafer
The resist was stripped by immersion in a 10% aqueous sodium hydroxide solution for 10 minutes. The plating was evaluated as ○.

[0046]

EXAMPLES 2-6, COMPARATIVE EXAMPLES 1-5 A photosensitive resin laminate having the photosensitive resin laminate shown in Tables 1 and 2 was prepared. Plating wiring was formed. Tables 1 and 2 also show the results of the resolution evaluation and the plating stripping evaluation. The meanings of the abbreviations of the photosensitive resin raw materials in Tables 1 and 2 are as follows. A-1: Methyl methacrylate / methacrylic acid / ethyl acrylate = 55/25/20 wt% polymer having a weight average molecular weight of 200,000 A-2: Methyl methacrylate / methacrylic acid / styrene / butyl methacrylate = 45/25/20 / 10w
Polymer having a weight average molecular weight of 100,000 at t% A-3: methyl methacrylate / methacrylic acid / styrene / butyl methacrylate / acrylonitrile = 37 /
Polymer having a weight average molecular weight of 120,000 at 22/9/19/13 wt% B-1: trimethylolpropane triacrylate B-2: trimethylolpropane ethylene oxide 6
Molar addition triacrylate CH ₃ —CH ₂ —C [CH ₂ —O— (CH ₂ CH ₂ O) ₂ —C
_{O-CH = CH 2] 3} B-3: trimethylolpropane trimethacrylate B-4: Bis (triethylene glycol dimethacrylate) polypropylene glycol _{CH 2 = C (CH 3)} -CO-O- (CH 2 CH 2 O) _{3 - - (CH (CH 3} ) CH 2 O) 12 - (CH 2 CH 2 O) 3 - -CO-C (CH 3) = CH 2 B-5: nonaethylene glycol diacrylate CH ₂ = CH-CO —O— (CH ₂ CH ₂ O) ₉ —CO—C
H = CH ₂ B-6: ethylene oxide-added dimethacrylate of bisphenol A CH ₂ ＣC (CH ₃ ) —CO—O— (CH ₂ CH ₂ O) ₅ −−φ−C (CH ₃ ) ₂ −φ− O— (CH ₂ CH ₂ O) ₅ ——CO—C (CH ₃ ) 2CH ₂ (where φ is a benzene ring) C-1: p, p′-bis (dimethylamino) benzophenone C-2: p, p'-Bis (diethylamino) benzophenone C-3: 2- (o-chlorophenyl) -4.5-diphenylimidazolyl dimer C-4: Benzophenone C-5: 2-benzyl-2-dimethylamino-1- (4
-Morpholinophenyl) butanone-1 (Ciba Geigy, trade name: Irgacure 369)

<Evaluation 2> A chromium layer having a thickness of 2000 angstroms was formed on a 5-inch silicon wafer by a sputtering apparatus manufactured by Anelva, and a copper layer having a thickness of 2000 angstroms was further formed. The photosensitive resin laminate of Example 1 was laminated thereon in the same manner as in Example 1. A mask was placed on the wafer on which the photosensitive resin laminate was laminated, and the wafer was exposed to 200 mJ / cm ² using a parallel light exposure machine HMW-801 manufactured by Oak. After removing the support, 3
A 1% aqueous solution of sodium carbonate at 0 ° C. was sprayed for 120 seconds, and the unexposed portion of the photosensitive resin layer was removed by development to form a resist pattern.

The result of the resolution evaluation A was ○. The wafer on which the resist is formed is degreased by immersing the wafer in an acidic cleaner (FRX manufactured by Atotech Japan) at 30 ° C. for 3 minutes, and then immersed in a solder plating solution (Plutin LA borofluoride bath manufactured by Meltex). Time electrolytic solder plating. The current density was adjusted to 1.5 A / dm ² . The height of the solder plating was 90 μm. The wafer after plating was immersed in a 3% aqueous solution of sodium hydroxide at 50 ° C. for 10 minutes to remove the resist. The plating was evaluated as ○.

[0049]

Example 7 Methyl methacrylate / methacrylic acid / ethyl acrylate = 55/25/20 wt% and a polymer having a weight average molecular weight of 200,000 was 60 parts by weight, and trimethylolpropane triacrylate was 30 as a polymerizable monomer.
Parts by weight, 10 parts by weight of 2-hydroxy-3-phenoxypropyl acrylate, 5 parts by weight of a 2,4,5-triarylimidazolyl dimer as a photoinitiator, and 0.1 part of p, p'-bis (dimethylamino) benzophenone. A liquid obtained by mixing and dissolving 05 parts by weight and 100 parts by weight of methyl ethyl ketone as a solvent is applied to a support (a polyethylene terephthalate film having a thickness of 19 μm) using a bar coater, dried, and covered with a protective film (a polyethylene film having a thickness of 30 μm). Thus, a photosensitive resin laminate (thickness of the photosensitive resin layer: 120 μm) was prepared.

A chromium layer having a thickness of 2000 angstroms was formed on a 5-inch silicon wafer by sputtering from Japan Vacuum, and a copper layer having a thickness of 2000 angstroms was further formed. The photosensitive resin laminate prepared above was laminated with a laminator AL-70 manufactured by Asahi Kasei Corporation so that the surface of the photosensitive resin layer was in close contact with the silicon wafer while peeling off the protective film. Lamination is performed at a roll temperature of 100 ° C and pressure of 3.5kg / c by air pressure.
m ² , speed was 1.0 m / min.

A mask was placed on the wafer on which the photosensitive resin laminate was laminated, and a mask aligner PL manufactured by Canon Inc. was used.
Exposure was performed with A-501F for 11 seconds. When the illuminance of the exposure machine was measured, it was 6.3 mW / cm ^2.
The exposure amount was mJ / cm ² . Immediately after the exposure, the wafer was placed in an oven at 80 ° C. and baked for 2 minutes after the exposure. After peeling off the support, paddle development was performed at room temperature using a 2.38% aqueous solution of tetramethylammonium hydroxide. The total development time for paddle development was 240 seconds. The unexposed portion of the photosensitive resin layer was developed and removed to form a resist pattern.

The result of the resolution evaluation B was ○. The wafer on which the resist is formed is degreased by immersing the wafer in an acidic cleaner (FRTX manufactured by Atotech Japan) at 30 ° C. for 3 minutes, and then electrolyzed in a copper sulfate plating solution (Copper Glyme 125 manufactured by Meltex Corporation) for 6 hours. Copper plated.
The current density was adjusted to be 2 A / dm ² . The height of the copper plating was 90 μm. 5 wafers after plating
The resist was stripped by immersion in a 3% aqueous sodium hydroxide solution at 0 ° C. for 10 minutes.

The plating was evaluated as ○. Diameter 1
A mask having a pattern in which dots of 50 μm were arranged was placed on a wafer on which a photosensitive resin laminate was laminated, and was exposed to a mask aligner PLA-501F manufactured by Canon Inc. for 11 seconds. After peeling off the support, paddle development was performed at room temperature using a 2.38% aqueous solution of tetramethylammonium hydroxide. This wafer was subjected to electrolytic copper plating in a copper sulfate plating solution to form a columnar copper wiring. The wafer after plating was immersed in an alkaline stripping solution at 50 ° C. for 10 minutes to strip the resist. The evaluation of peelability of the cured resist was ○.

[0054]

Examples 8 to 10 and Comparative Examples 6 to 8 Photosensitive resin laminates having the photosensitive resin laminates shown in Table 3 were prepared.
In the same manner as described above, wiring of copper electroplating on the wafer was formed. Table 3 also shows the results of the evaluation of the resolution, the evaluation of the plating removal, and the evaluation of the peelability of the cured resist. Abbreviations of photosensitive resin raw materials other than the above-mentioned raw materials have the following meanings. B-7: 2-hydroxy-3-phenoxypropyl acrylate B-8: Phenoxyhexaethylene glycol acrylate B-9: β-hydroxypropyl-β ′-(acroyloxy) propyl phthalate B-10: 4-normal octylphenoxy Pentaethylene glycol tripropylene glycol acrylate

[0055]

[Table 1]

[0056]

[Table 2]

[0057]

[Table 3]

[0058]

As described above, when the photosensitive resin laminate of the first invention of the present application is used, in forming a CSP, in forming wiring for connecting a chip terminal and an external terminal, an excellent resolution is obtained. As a result, fine wiring can be formed, and a high-quality conductive wiring free from plating in the conductive plating step can be obtained, which is extremely suitable for CSP production. According to the second invention of the present application,
It is possible to obtain a highly reliable circuit in which the resist is easily stripped after plating and has no peeling residue.

Claims (2)

[Claims] 1. A photosensitive resin layer comprising a support and a photosensitive resin layer, wherein the photosensitive resin layer has (1) a carboxyl group content of 1 in acid equivalent.
Polymer having a weight average molecular weight of 20,000 to 500,000: 20 to 90% by weight, and (2) one or more polymerizable monomers containing at least a compound represented by the following formula (1) : 10 to 60% by weight, (Where X represents a hydrogen atom, a methyl group or a hydroxyl group. A represents a copolymer residue of CH ₂ CH (CH ₃ ) O and CH ₂ CH ₂ O, and n represents an integer of 0 to 5. R represents a hydrogen atom or a methyl group), and (3) at least one p-aminophenyl ketone: 0.001 to 0.1.
A photosensitive resin laminate characterized by containing by weight. 2. A photosensitive resin layer comprising a support and a photosensitive resin layer, wherein the photosensitive resin layer comprises (1) a carboxyl group having an acid equivalent of 1%.
Polymer having a weight average molecular weight of 20,000 to 500,000: 20 to 90% by weight, (2) at least i) Formula (1)
A compound represented by the following formula: (Where X represents a hydrogen atom, a methyl group or a hydroxyl group. A represents a copolymer residue of CH ₂ CH (CH ₃ ) O and CH ₂ CH ₂ O, and n represents an integer of 0 to 5. R represents a hydrogen atom or a methyl group.) And ii) two or more polymerizable monomers including a compound having one acrylate group: 10 to 60% by weight, and (3) at least one type of p -Aminophenyl ketone: 0.001 to 0.1
A photosensitive resin laminate characterized by containing by weight.