JP2014219636A - Uv-curable sheet material, uv-curable dry film and insulation material for uv-curable buildup - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a UV-curable sheet material which has good patterning properties and a small thermal expansion coefficient.SOLUTION: A UV-curable sheet material 1 is composed of a UV-curable resin composition, and the resin composition contains a UV-curable resin and a filler. The content of the filler is 45 vol.% or more of the whole resin composition. The UV-curable sheet material 1 has a UV transmissivity at the 365-nm wavelength of 50% or higher.

Description

  The present invention is used when producing a printed wiring board by an ultraviolet curable sheet material formed from an ultraviolet curable resin composition, an ultraviolet curable dry film used for soldering a printed wiring board, and a build-up method. The present invention relates to an insulating material for buildup.

  With the demand for higher performance, smaller size and thinner electronic parts, various resin compositions have been proposed as insulating materials corresponding to the demand. Resin compositions are roughly classified into thermosetting and ultraviolet curable depending on the curing system.

  Thermosetting resin compositions are widely used because they can be cured regardless of the shape and optical properties (transparency). And since a thermosetting resin composition is easy to combine a filler, a highly functional thermosetting resin composition having high heat resistance, low coefficient of thermal expansion or high elasticity has long been proposed (for example, Patent Document 1).

  However, when using the above thermosetting resin composition for solder resists, insulating materials for electric circuits, embedded materials for embedded parts, etc., processing with a drill, laser, etc. is required for pattern formation and drilling. However, there are problems that the process becomes complicated and that process time and process cost are increased.

  On the other hand, the ultraviolet curable resin composition can be formed with a pattern much more easily than the above thermosetting resin composition by using an exposure and development process using a photomask.

  However, when the ultraviolet curable resin is combined with a filler in order to have high heat resistance or low thermal expansion coefficient, the ultraviolet ray is scattered and hardly hardens to the inside of the resin composition, particularly to the bottom. Moreover, since ultraviolet rays are scattered at the interface between the ultraviolet curable resin and the filler contained in the ultraviolet curable resin composition and high photosensitivity is difficult to obtain, there is a problem that patterning properties are lowered. Therefore, it has been difficult to obtain an ultraviolet curable resin composition having high heat resistance or low thermal expansion coefficient.

  As a technique for overcoming these problems, for example, the inventions described in Patent Document 2 and Patent Document 3 can be cited. Patent Document 2 proposes an invention related to a solder resist that can be exposed and developed containing a filler, and Patent Document 3 proposes an invention related to a printed wiring board that contains a filler and can be exposed and developed. In these two inventions, by making the refractive index of the ultraviolet curable resin and filler contained in the ultraviolet curable resin composition close to each other, the ultraviolet light scattering property of the ultraviolet curable resin composition is lowered and the pattern can be formed. A curable resin composition is proposed.

  However, in the invention described in Patent Document 2, since the ultraviolet rays are scattered, the average particle size of the filler is limited to 0.5 μm or less, and the filler amount is limited in such a small particle size filler. The In addition, in the invention described in Patent Document 3, since the photosensitivity is lowered, the filler content is limited to 50% by mass or less of the entire resin composition. Therefore, it cannot be said that the high heat resistance or the low coefficient of thermal expansion of these two ultraviolet curable resin compositions is sufficient.

  Patent Document 4 proposes an invention relating to a dry film that can be exposed and developed and contains a filler with a refractive index limited.

  However, in the present invention, when the filler content increases, the moldability decreases and the water absorption increases, so the filler content is limited to 40% by volume or less of the entire resin composition. Therefore, it cannot be said that this ultraviolet curable resin composition has sufficient high heat resistance or low thermal expansion coefficient.

Japanese Patent No. 4224907 International Publication No. 2006/004158 JP 2004-126159 A JP 2011-75923 A

  The present invention has been made in view of the above points, and provides an ultraviolet curable sheet material, an ultraviolet curable dry film, and an ultraviolet curable build-up insulating material having good patternability and a low coefficient of thermal expansion. It is for the purpose.

  The ultraviolet curable sheet material according to the present invention is an ultraviolet curable sheet material formed of an ultraviolet curable resin composition, wherein the resin composition contains an ultraviolet curable resin and a filler, and the filler content is It is 45 volume% or more of the whole resin composition, and the ultraviolet-ray transmittance of the said ultraviolet curable sheet material of wavelength 365nm is 50% or more, It is characterized by the above-mentioned.

  In the ultraviolet curable sheet material, the linear expansion coefficient is preferably 45 ppm / K or less.

  In the ultraviolet curable sheet material, the filler preferably has an average particle diameter of 1 to 50 μm.

  In the ultraviolet curable sheet material, the filler preferably contains crystalline silica.

  In the ultraviolet curable sheet material, the ultraviolet curable resin preferably contains at least 50 to 70% by mass of a resin having an oxiranylcyclohexane structure or a resin having a 3 ', 4'-epoxycyclohexylmethyl structure.

  In the ultraviolet curable sheet material, the filler preferably contains spherical E glass.

  In the ultraviolet curable sheet material, the ultraviolet curable resin preferably contains 20 to 50% by mass of a resin having at least an oxiranylcyclohexane structure or a resin having a 3 ', 4'-epoxycyclohexylmethyl structure.

  In the ultraviolet curable sheet material, the filler preferably contains spherical alumina.

  In the ultraviolet curable sheet material, the ultraviolet curable resin preferably contains a fluorene resin.

  In the ultraviolet curable sheet material, the ultraviolet curable resin preferably contains 50 to 100% by mass of a fluorene resin.

  In the ultraviolet curable sheet material, the filler preferably contains a spherical glass frit having a refractive index of 1.52 to 1.65.

  The ultraviolet curable dry film according to the present invention is formed by laminating the ultraviolet curable sheet material on a carrier substrate.

  The ultraviolet curable build-up insulating material according to the present invention is formed by laminating the ultraviolet curable sheet material on a carrier substrate.

  According to the present invention, since the ultraviolet ray transmittance of the ultraviolet curable sheet material is high, scattering and reflection of ultraviolet rays at the interface between the ultraviolet curable resin and the filler are suppressed, and the patterning property is improved. Further, since the content of the filler in the ultraviolet curable sheet material is large, the coefficient of thermal expansion can be lowered.

An example of the ultraviolet curable sheet material which concerns on this invention is shown, (a) (b) is sectional drawing. It is sectional drawing which shows an example of the semiconductor package using the ultraviolet curable sheet material which concerns on this invention. It is sectional drawing which shows an example of the printed circuit board using the ultraviolet curable sheet material which concerns on this invention. An example of the evaluation method of patterning property is shown, (a) is sectional drawing at the time of exposure, (b) is sectional drawing after image development.

  Embodiments of the present invention will be described below.

  The ultraviolet curable sheet material according to the present invention is formed of a resin composition that is cured by ultraviolet rays. This resin composition contains a composite of an ultraviolet curable resin and a filler.

  First, the ultraviolet curable resin will be described. The ultraviolet curable resin is not particularly limited as long as it is a compound that is cured by the action of a photopolymerization initiator, and may be in any form of a monomer, an oligomer, a prepolymer, and a resin.

  For example, as the ultraviolet curable resin, only one kind such as an acrylic resin, an epoxy resin, and a silicone resin can be used, or two or more kinds can be used in combination. In particular, a resin that is cured by light and cured by heat is preferable because the degree of curing can be easily controlled during exposure and development. As such a resin, an epoxy resin is suitable. Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, aralkyl epoxy resin, phenol novolac type epoxy resin, alkylphenol novolac type epoxy resin, biphenol type epoxy resin, and naphthalene type epoxy. Resin, dicyclopentadiene type epoxy resin, epoxy compound of condensate of phenol and aromatic aldehyde having phenolic hydroxyl group, triglycidyl isocyanurate, alicyclic epoxy resin, etc. Two or more types can be used in combination.

  Moreover, an epoxy resin can be divided into a liquid epoxy compound and a solid epoxy compound as follows, and these can also be used.

  Specific examples of the liquid epoxy compound include a liquid bisphenol A type epoxy compound (for example, “Epiclon 850S” manufactured by DIC Corporation), a liquid bisphenol F type epoxy compound (for example, “Epiclon 830S” manufactured by DIC Corporation), and liquid bisphenol E. Type epoxy compound, liquid bisphenol type epoxy compound such as liquid bisphenol S type epoxy compound, liquid hydrogenated bisphenol A type epoxy compound (for example, “YX8000” manufactured by Japan Epoxy Resin Co., Ltd.), liquid hydrogenated bisphenol F type epoxy compound, liquid type Liquid hydrogenated bisphenol type epoxy compounds such as hydrogenated bisphenol E type epoxy compounds, liquid hydrogenated bisphenol S type epoxy compounds, liquid 3 ′, 4′-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxyl Rate (for example, “Celoxide 2021P” manufactured by Daicel Chemical Industries, Ltd.), liquid ε-caprolactone-modified 3 ′, 4′-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate (for example, “Celoxide 2081 manufactured by Daicel Chemical Industries, Ltd.) )) Or the like, and an epoxy compound having a liquid 3 ′, 4′-epoxycyclohexylmethyl skeleton (resin having a 3 ′, 4′-epoxycyclohexylmethyl structure). In particular, among the above liquid epoxy compounds, it is preferable to use a resin having a 3 ', 4'-epoxycyclohexylmethyl structure. Thereby, scattering of ultraviolet rays can be easily reduced at the interface between the ultraviolet curable resin and the filler, and high photosensitivity can be obtained, so that the curing rate can be increased.

  Specific examples of the solid epoxy compound include a solid bisphenol A type epoxy compound (for example, “Epicoat 1006FS” manufactured by Japan Epoxy Resin Co., Ltd.) and a solid bisphenol F type epoxy compound (for example, “Epicoat 4007” manufactured by Japan Epoxy Resin Co., Ltd.). , Solid bisphenol E type epoxy compound, solid bisphenol type epoxy compound such as solid bisphenol S type epoxy compound, solid hydrogenated bisphenol A type epoxy compound (for example, “YL7170” manufactured by Japan Epoxy Resins Co., Ltd.), solid hydrogenated bisphenol F type Solid hydrogenated bisphenol type epoxy compounds such as epoxy compounds, solid hydrogenated bisphenol E type epoxy compounds, solid hydrogenated bisphenol S type epoxy compounds, solid 2,2-bis (hydroxymethyl) -1-butane 1,2-epoxy-4- (2-oxiranyl) cyclohexane adduct (eg, “EHPE3150” manufactured by Daicel Chemical Industries, Ltd.), a fluorene-based epoxy resin (for example, Osaka) And fluorene-based resins such as “CG-500” manufactured by Gas Chemical Co., Ltd. Of the above solid epoxy compounds, it is preferable to use a resin having an oxiranylcyclohexane structure or a fluorene-based resin. Thereby, it becomes easy to reduce scattering of ultraviolet rays at the interface between the ultraviolet curable resin and the filler.

Next, the photopolymerization initiator will be described. Examples of the photopolymerization initiator include a cationic photopolymerization initiator and a radical photopolymerization initiator. For example, the above epoxy resin functions as an ultraviolet curable resin when used together with a cationic photopolymerization initiator. The photocationic polymerization initiator is a polymerization initiator that causes ring-opening self-polymerization of an epoxy group of an epoxy compound by light. Such a cationic photopolymerization initiator includes not only a cationic photopolymerization initiator that can be cured only by light, but also a cationic photopolymerization initiator that can initiate curing by light or heat. If it is with these initiators, you may use the thermal cationic polymerization initiator which can start hardening only by a heat | fever. Specific examples of the cationic photopolymerization initiator, Ltd. ADEKA "SP-170" ^- include (SbF ₆ sulfonium salt). A photoinitiator can use only 1 type, or can be used in combination of 2 or more type. The photopolymerization initiator is preferably blended in the range of 0.5 to 2 parts by mass with respect to 100 parts by mass of the ultraviolet curable resin in the resin composition.

  Next, the filler will be described. The filler is not particularly limited as long as it can make the transmittance of ultraviolet rays with a wavelength of 365 nm (preferably a wavelength of 350 to 400 nm) of the ultraviolet curable sheet material 50% or more (upper limit is 99%). Absent.

  The average particle size of the filler is preferably 0.03 to 100 μm. When the average particle size is 0.03 μm or more, it can be avoided that the manufacture of the filler is difficult, and when the average particle size is 100 μm or less, the electronic component is reduced in size and thickness. It is difficult to become an impeding factor. In particular, the average particle size of the filler is more preferably 1 to 50 μm. When the average particle size is 1 μm or more, it becomes easy to highly fill the UV curable sheet material with filler, and when the average particle size is 50 μm or less, electronic components can be easily downsized and thinned. Can do. In the present specification, the average particle diameter means a particle diameter at an integrated value of 50% in a particle size distribution obtained by observation with a scanning electron microscope.

  Examples of the shape of the filler include a spherical shape, a crushed shape, and a scaly shape, but a spherical shape is preferable because the filling amount can be increased.

  The refractive index of the filler is preferably 1.52 to 1.65 when measured based on JIS K 7142 (wavelength 550 nm). In this case, in the ultraviolet region having a wavelength of 350 to 400 nm, the refractive index of the filler and the refractive index of the ultraviolet curable resin are easily brought close to each other, and ultraviolet rays are hardly scattered and reflected at the interface between the filler and the ultraviolet curable resin. Therefore, the transmittance of ultraviolet rays (particularly, wavelength 365 nm) of the ultraviolet curable sheet material tends to be 50% or more, and the patterning property is easily improved. For example, the ultraviolet transmittance at a wavelength of 365 nm of an ultraviolet curable sheet material having a thickness of 50 μm tends to be 50% or more. In addition, in this specification, a refractive index means what is measured based on JISK7142 (wavelength 550nm).

  As the filler, for example, it is preferable to use only one kind of crystalline silica, fused silica, E glass, alumina, glass frit, T glass or the like, or to contain two or more kinds. Examples of the crystalline silica include “C-BASE-1” (crushed, average particle size 5.0 μm, refractive index 1.55) manufactured by Tatsumori, and “5X” (crushed, manufactured by Tatsumori). And an average particle size of 1.5 μm, a refractive index of 1.55), “Crystalite 3K-S” (average particle size of 35 μm) manufactured by Tatsumori Co., Ltd., and the like. Examples of the E glass include “spherical E glass” (average particle size: 5.0 μm, refractive index: 1.56) manufactured by Asahi Schwer Co., Ltd. As the alumina, for example, “DAW-45” (spherical, average particle size 43 μm) manufactured by Denki Kagaku Kogyo Co., Ltd., “DAW-05” (spherical, average particle size 5.0 μm, refracted) manufactured by Denki Kagaku Kogyo Co., Ltd. 1.65), “ASFP-20” (average particle size 0.3 μm) manufactured by Denki Kagaku Kogyo Co., Ltd., and the like. Examples of the glass frit include “CF0111” (average particle size 15 μm, refractive index 1.524) manufactured by Nippon Frit Co., Ltd.

  The surface of the filler is preferably pretreated with a surface treatment agent such as a silane coupling agent in order to improve wettability with the ultraviolet curable resin as necessary. Especially when a coupling agent such as epoxy silane, vinyl silane, mercapto silane, amino silane, styryl silane, methacryloxy silane, acryloxy silane, titanate or the like is used as a surface treatment agent, the filler in the resin composition The dispersibility of can be improved. Of the above coupling agents, epoxy silane-based and vinyl silane-based coupling agents are particularly preferable because they hardly inhibit photopolymerization.

  The filler content is 45% by volume or more of the entire resin composition, and preferably 60% by volume or more (the upper limit is 90% by volume). When the filler content is 45% by volume or more, the linear expansion coefficient of the ultraviolet curable sheet material can be easily reduced to 45 ppm / K or less, the thermal expansion coefficient can be lowered, and the heat resistance can be increased. It is.

  The resin composition contains the ultraviolet curable resin and filler described above, and the following combinations are particularly preferable.

  When the filler contains crystalline silica, the UV curable resin may be a resin having at least an oxiranylcyclohexane structure or a resin having a 3 ′, 4′-epoxycyclohexylmethyl structure in an amount of 50 to 50% of the entire UV curable resin. It is preferable to contain 70 mass%. This means that only 50 to 70% by mass of a resin having an oxiranylcyclohexane structure, 50 to 70% by mass of only a resin having a 3 ′, 4′-epoxycyclohexylmethyl structure, This means that the total content of the resin having a ranylcyclohexane structure and the resin having a 3 ′, 4′-epoxycyclohexylmethyl structure is 50 to 70% by mass. This makes it easy to bring the refractive index of the filler close to the refractive index of the ultraviolet curable resin in the ultraviolet region of a wavelength of 350 to 400 nm, and easily reduces the scattering and reflection of ultraviolet rays at the interface between the filler and the ultraviolet curable resin. Become.

  When the filler contains spherical E glass, at least 20 to 50% by mass of the resin having an oxiranylcyclohexane structure or a resin having a 3 ′, 4′-epoxycyclohexylmethyl structure is contained in the entire ultraviolet curable resin. It is preferable to do. This means that only 20-50% by mass of a resin having an oxiranylcyclohexane structure, 20-50% by mass of only a resin having a 3 ′, 4′-epoxycyclohexylmethyl structure, This means that the total content of the resin having a ranylcyclohexane structure and the resin having a 3 ′, 4′-epoxycyclohexylmethyl structure is 20 to 50% by mass. This makes it easy to bring the refractive index of the filler close to the refractive index of the ultraviolet curable resin in the ultraviolet region of a wavelength of 350 to 400 nm, and easily reduces the scattering and reflection of ultraviolet rays at the interface between the filler and the ultraviolet curable resin. Become.

  When the filler contains spherical alumina, it is preferable to contain a fluorene-based resin, and it is more preferable to contain the fluorene-based resin in an amount of 50 to 100% by mass of the entire ultraviolet curable resin. This makes it easy to bring the refractive index of the filler close to the refractive index of the ultraviolet curable resin in the ultraviolet region of a wavelength of 350 to 400 nm, and easily reduces the scattering and reflection of ultraviolet rays at the interface between the filler and the ultraviolet curable resin. Become.

  The ultraviolet curable sheet material according to the present invention can be manufactured as follows.

  First, the above ultraviolet curable resin, photopolymerization initiator and filler are kneaded, and a solvent is further blended, and then the ultraviolet curable resin, photopolymerization initiator and filler are dissolved and dispersed in the solvent to obtain a slurry-like resin. A resin varnish of the composition is prepared. The solvent is not particularly limited as long as it can dissolve the ultraviolet curable resin and disperse the filler. For example, ketones such as methyl ethyl ketone, aromatic hydrocarbons, glycol ethers, glycols Ether acetates, esters, alcohols, aliphatic hydrocarbons, petroleum solvents, dimethyl sulfoxide, and the like can be used. In particular, in order to improve the dispersibility of the filler in the resin composition, a dispersant may be further blended. Examples of the dispersant that can be used include alkyl ether-based, sorbitan ester-based, alkyl polyether amine-based, and polymer-based dispersants. Of the above dispersants, alkyl ether-based and alkyl polyether amine-based dispersants are particularly preferable because they hardly inhibit photopolymerization.

  Next, the above resin varnish is applied to one or both sides of a carrier base material, and this is heated and dried by hot air spraying or the like to remove the solvent, and as shown in FIG. The sheet material 1 can be obtained in a state of being laminated on the carrier substrate 4. As shown in FIG. 1 (b), a protective substrate 5 may be laminated on the ultraviolet curable sheet material 1. This improves the handleability. Usually, the protective substrate 5 is peeled off immediately before the ultraviolet curable sheet material 1 is bonded to another member, and the carrier substrate 4 is peeled off after the ultraviolet curable sheet material 1 is exposed.

  As the carrier substrate 4 and the protective substrate 5, for example, a polymer film, a metal sheet, a release paper or the like can be used. Examples of the polymer film include polyolefin films such as polyethylene film, polypropylene film, and polyvinyl chloride film, polyester films such as polyethylene terephthalate (PET) film, and polycarbonate films. As a metal sheet, metal foil, such as copper foil, aluminum foil, nickel foil, is mentioned, for example. It is preferable that the surface of the carrier base material 4 and the protective base material 5 on which the ultraviolet curable sheet material 1 is stacked is previously subjected to mold release treatment with organopolysiloxane or the like. As for the thickness of the carrier base material 4 and the protective base material 5, 10-150 micrometers is common. The carrier base material 4 and the protective base material 5 are preferably polyester films in terms of cost and heat resistance.

  The thickness of the ultraviolet curable sheet material 1 is not particularly limited as long as the ultraviolet ray transmittance of the ultraviolet curable sheet material at a wavelength of 365 nm is 50% or more, but is, for example, 10 to 1000 μm. If the thickness of the ultraviolet curable sheet material 1 is 10 μm or more, even if the filler is miniaturized, it is difficult to cause a problem in the filling property. If the thickness of the ultraviolet curable sheet material 1 is 1000 μm or less, voids are hardly generated inside even if the drying time of the resin varnish applied to the carrier substrate 4 is short. If the ultraviolet curable sheet material 1 having a thickness exceeding 1000 μm is required, it is practically preferable to use the necessary number of the ultraviolet curable sheet material 1 having a thickness of 10 to 1000 μm.

  In the present invention, the transmittance of ultraviolet rays having a wavelength of 365 nm of the ultraviolet curable sheet material 1 is 50% or more. If this is satisfied, the thickness of the ultraviolet curable sheet material 1 can be set, for example, in the range of 10 μm to 50 μm, or in the range of 50 μm to 1000 μm. Thus, when the ultraviolet ray transmissive sheet material 1 has a high ultraviolet ray transmittance, scattering and reflection of ultraviolet rays at the interface between the ultraviolet curable resin and the filler are suppressed, and the patterning property is improved.

  Next, a usage example of the ultraviolet curable sheet material 1 will be described.

  1 formed by laminating the ultraviolet curable sheet material 1 on the carrier substrate 4 can be used as an ultraviolet curable dry film. FIG. 2 shows a semiconductor package, and an example in which the above-described ultraviolet curable dry film is used for forming a solder resist in the semiconductor package. The solder resist is formed by adhering the ultraviolet curable sheet material 1 of an ultraviolet curable dry film to both surfaces of an interposer 6 provided with a first pad 7 on the front surface and a second pad 8 on the back surface, and then exposing and developing. Can be done. Adhesion can be performed by laminating with a simple laminator or a vacuum laminator, or by direct pressure molding or the like. Thereafter, the semiconductor chip 9 is mounted on the surface of the interposer 6, the semiconductor chip 9 and the first pad 7 are electrically connected by the bonding wire 10, and then the semiconductor chip 9 is sealed with the mold resin 11. On the other hand, by providing the solder balls 12 on the second pad 8, a semiconductor package as shown in FIG. 2 can be manufactured.

  The ultraviolet curable dry film can also be used for pattern formation. When patterning is performed, the ultraviolet curable sheet material 1 is bonded to a predetermined member, and then a mask on which a core pattern slit is formed is overlapped, and exposure is performed by irradiating ultraviolet rays through the slit. As an exposure method, in addition to a selective exposure method using a mask, a direct drawing method of scanning and irradiating a laser beam along a pattern shape can be employed. After the exposure, the ultraviolet curable sheet material 1 is developed using a developer such as an aqueous flux cleaning agent to remove the uncured resin that is not exposed. Thereby, a predetermined pattern can be formed.

  Moreover, what was formed by laminating | stacking the ultraviolet curable sheet material 1 on the carrier base material 4 can also be used as an insulating material for ultraviolet curable buildup. FIG. 3 shows an example in which an electronic component 17 such as LSI is mounted on a multilayer printed wiring board (printed circuit board). In this multilayer printed wiring board, the above-described ultraviolet curable build-up insulating material is used for forming an insulating layer. Indicates. The insulating layer is formed by adhering the ultraviolet curable sheet material 1 of the ultraviolet curable build-up insulating material to both surfaces of the core material 13 provided with the conductor layer 14 and the via hole 15, and then exposing and developing. Can do. In this way, an insulating layer provided with the photo via hole 16 can be formed. After forming as many insulating layers as necessary using the build-up method, the electronic component 17 is mounted on the outermost layer and soldering is performed. By performing electrical connection by attaching, a printed circuit board as shown in FIG. 3 can be manufactured.

Moreover, you may use the ultraviolet curable sheet material 1 as follows. For example, the ultraviolet curable sheet material 1 is placed on the surface of the semiconductor wafer (the active surface or the opposite surface), and bonded by heating at 80 to 180 ° C. for several seconds to 5 minutes. And after peeling a carrier base material, it irradiates with ultraviolet rays of energy of 50-2000 mJ / cm < ² >, for example with a high pressure mercury lamp etc., puts into a dryer, and heats again at 100-200 degreeC for 1 minute-2 hours. Harden completely. Through the above steps, a substrate having a coating film formed on the surface of a semiconductor wafer can be obtained.

  Hereinafter, the present invention will be specifically described by way of examples.

(Constituent components of resin composition)
In manufacturing the ultraviolet curable sheet material, the following were used as the resin.

Bisphenol A type epoxy compound (liquid): “Epiclon 850S” manufactured by DIC Corporation
Bisphenol A type epoxy compound (solid): “Epicoat 1006FS” manufactured by Japan Epoxy Resin Co., Ltd.
1,2-epoxy-4- (2-oxiranyl) cyclohexane adduct of 2,2-bis (hydroxymethyl) -1-butanol: “EHPE3150” manufactured by Daicel Chemical Industries, Ltd.
3 ′, 4′-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate: “Celoxide 2021P” manufactured by Daicel Chemical Industries, Ltd.
Fluorene epoxy resin: “CG-500” manufactured by Osaka Gas Chemical Co., Ltd.
The following fillers were used.

Crushed crystal silica 1: “C-BASE-1” manufactured by Tatsumori Co., Ltd. (average particle size 5 μm, refractive index 1.55)
Crushed crystal silica 2: “5X” manufactured by Tatsumori Co., Ltd. (average particle size 1.5 μm, refractive index 1.55)
Spherical E Glass: “Spherical E Glass” manufactured by Asahi Schavel Co., Ltd. (average particle size 5 μm, refractive index 1.56)
Spherical glass frit: “CF0111” manufactured by Nippon Frit Co., Ltd. (average particle size 15 μm, refractive index 1.524)
Spherical Alumina 1: “DAW-05” manufactured by Denki Kagaku Kogyo Co., Ltd. (average particle size 5 μm, refractive index 1.65)
Spherical alumina 2: “AO502” manufactured by Admatechs Co., Ltd. (average particle size 0.7 μm, refractive index 1.65)
Spherical fused silica: “FB3SDX” manufactured by Denki Kagaku Kogyo Co., Ltd. (average particle size 3 μm, refractive index 1.47)
Moreover, the following were used as a photoinitiator.

Photo-cationic polymerization curing agent: manufactured) ADEKA "SP-170" (SbF ₆ ^- sulfonium salt)
(UV curable sheet material)
A resin varnish having a viscosity of 3000 cps was prepared by kneading the resin, filler and photopolymerization initiator in a blending amount (parts by mass) shown in Table 1 with a planetary mixer and further blending with methyl ethyl ketone.

  Next, the above resin varnish was applied to a carrier substrate made of a polyethylene terephthalate (PET) film having a thickness of 75 μm using a multi coater (manufactured by Hirano Tech Seed Co., Ltd.) of a comma coater head. This carrier base material is obtained by applying an organopolysiloxane in advance to the application surface of the resin varnish and performing a release treatment. And it heat-dried at 130 degreeC for 8 minute (s), and manufactured the ultraviolet curable sheet material which consists of an epoxy resin composition of the B stage state by the thickness of Table 1 on the single side | surface of a carrier base material.

[Filler content]
The filler content (volume%) in the entire resin composition was determined from the density of each resin, filler, and photopolymerization initiator.

[Transmissivity]
Using a visible ultraviolet spectrophotometer “U-4100” manufactured by Hitachi, Ltd., the transmittance of ultraviolet rays having a wavelength of 365 nm was measured for each ultraviolet curable sheet material in a state of being laminated on a carrier substrate.

[Patternability]
The patterning property was evaluated as shown in FIG. First, using a pressure-type vacuum laminator (“V130” manufactured by Nichigo Morton Co., Ltd.), an ultraviolet curable sheet material 1 ( (Containing UV curable resin 2 and filler 3).

As the mask 19, a mask having a light transmitting part 20 and a light shielding part 21 having a diameter φ ₁ = 200 μm was used. After this mask 19 is overlaid on the carrier substrate 4 as shown in FIG. 4 (a), ultraviolet rays (open arrows in FIG. 4) are irradiated under the condition of 500 mJ / cm ² using an ultrahigh pressure mercury lamp. A portion of the ultraviolet curable sheet material 1 exposed through the light transmitting portion 20 of the mask 19 was photocured.

  Next, after peeling the mask 19 and the carrier substrate 4 from the ultraviolet curable sheet material 1, heat treatment was performed at 140 ° C. for 2 minutes. Subsequently, a non-exposed portion of the ultraviolet curable sheet material 1 is dissolved and removed by developing with an aqueous flux cleaning agent adjusted to 55 ° C. (“Pine Alpha ST-100SX” manufactured by Arakawa Chemical Industries, Ltd.). , Washed with water. Then, after the surface moisture was blown with air and dried at 100 ° C. for 10 minutes, the opening 22 was formed in the cured ultraviolet curable sheet material 1 as shown in FIG.

The bottom diameter (φ ₂ ) of the opening 22 was observed using a 1000 × scanning electron microscope (SEM), measured, and the patternability was evaluated according to the following criteria.

“◎”: Bottom diameter of 180 μm or more and 200 μm or less “◯”: Bottom diameter of 160 μm or more and less than 180 μm “X”: Bottom diameter of less than 160 μm [Linear expansion coefficient]
The ultraviolet curable sheet material was photocured by irradiating with ultraviolet rays using an ultra-high pressure mercury lamp at 500 mJ / cm ² , and then the linear expansion coefficient was measured according to JIS K7197.

  As is clear from Table 1, in Examples 1 to 10, it was confirmed that the patterning property was good, the linear expansion coefficient was 45 ppm / K or less, and the thermal expansion coefficient was low.

  On the other hand, in Comparative Example 1, although the coefficient of thermal expansion was low, it was confirmed that the patternability was not good because of the low transmittance of ultraviolet rays.

  In Comparative Example 2, it was confirmed that the thermal expansion coefficient was high because the transmittance of ultraviolet rays was low, the patterning property was not good, and the filler content was low.

1 UV curable sheet material 2 UV curable resin 3 Filler 4 Carrier base material

Claims (13)

  In the ultraviolet curable sheet material formed of the ultraviolet curable resin composition, the resin composition contains an ultraviolet curable resin and a filler, and the filler content is 45% by volume or more of the entire resin composition. An ultraviolet curable sheet material, wherein the ultraviolet curable sheet material has an ultraviolet transmittance of a wavelength of 365 nm of 50% or more.   The ultraviolet curable sheet material according to claim 1, wherein the linear expansion coefficient is 45 ppm / K or less.   The ultraviolet curable sheet material according to claim 1, wherein the filler has an average particle diameter of 1 to 50 μm.   The ultraviolet curable sheet material according to claim 1, wherein the filler contains crystalline silica.   5. The ultraviolet ray according to claim 4, wherein the ultraviolet curable resin contains at least 50 to 70% by mass of a resin having an oxiranylcyclohexane structure or a resin having a 3 ′, 4′-epoxycyclohexylmethyl structure. Curable sheet material.   The ultraviolet curable sheet material according to claim 1, wherein the filler contains spherical E glass.   7. The ultraviolet ray according to claim 6, wherein the ultraviolet curable resin contains at least 20 to 50% by mass of a resin having an oxiranylcyclohexane structure or a resin having a 3 ′, 4′-epoxycyclohexylmethyl structure. Curable sheet material.   The ultraviolet curable sheet material according to claim 1, wherein the filler contains spherical alumina.   The ultraviolet curable sheet material according to claim 8, wherein the ultraviolet curable resin contains a fluorene resin.   The ultraviolet curable sheet material according to claim 9, wherein the ultraviolet curable resin contains 50 to 100% by mass of a fluorene-based resin.   The ultraviolet curable sheet material according to any one of claims 1 to 3, wherein the filler contains a spherical glass frit having a refractive index of 1.52 to 1.65.   An ultraviolet curable dry film formed by laminating the ultraviolet curable sheet material according to any one of claims 1 to 11 on a carrier substrate.   An insulating material for ultraviolet curable build-up, wherein the ultraviolet curable sheet material according to any one of claims 1 to 12 is laminated on a carrier substrate.

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