JP2014075577A - Method of producing resin layer having pattern, and resin composition for use therein - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for forming a resin layer having a good pattern easily.SOLUTION: A method for forming a resin layer having a pattern includes a step for forming a pattern, inverted for an uneven pattern, in a resin layer 10a, by pressing a mold having an uneven pattern against the resin layer 10a composed of a resin composition containing a polymerizable unsaturated compound. The polymerizable unsaturated compound includes a (meth)acrylate compound having an urethane bond.

Description

  The present invention relates to a method for producing a resin layer having a pattern, and a resin composition used therefor.

  Conventionally, in order to form a surface protective layer or an interlayer insulating layer of a semiconductor element, a polyimide resin having excellent heat resistance, electrical characteristics, mechanical characteristics, and the like has been used. However, with the recent progress of high integration and miniaturization of semiconductor elements, surface mounting methods such as LOC (Lead-on-Chip) or solder reflow have been adopted to cope with the thinning and miniaturization of sealing resin packages. Therefore, a polyimide resin excellent in mechanical properties, heat resistance and the like is required more than ever.

  By using the photosensitive polyimide resin, the process of forming a pattern can be simplified and a complicated manufacturing process can be shortened (for example, refer to Patent Documents 1 to 4).

  As a method for forming a fine pattern using a photosensitive polyimide resin in a manufacturing process of a semiconductor element or various information recording media, there are electron beam lithography, focused ion beam lithography, and the like. However, since these methods require a plurality of steps such as exposure and development, there is a problem that the throughput (processing capacity per unit time) is small.

  In recent years, an imprint method has been proposed as an alternative to electron beam lithography, focused ion beam lithography, or the like (Patent Document 5). According to the imprint method, by pressing the mold against the resin layer and transferring the shape of the mold to the resin layer, it is possible to form a fine pattern of submicron or less with high throughput.

  Among the imprint methods, the UV nanoimprint method that irradiates the resin layer with ultraviolet light while the mold is pressed, and the thermal imprint method that heats the resin layer while the mold is pressed have excellent pattern transfer accuracy and resolution. In particular, application to semiconductor device manufacturing is expected (for example, Patent Document 6). In these methods, the resin layer is deformed by pressing a mold having a fine pattern against the resin layer in a liquid or soft state, and the resin layer is cured in that state, thereby patterning the resin layer.

Japanese Patent No. 3712164 JP 2006-173655 A JP 2008-1876 A JP 2008-1877 A JP 2000-232095 JP-T-2006-521682

  Resin layers containing various polymer materials such as polyimide resin have excellent heat resistance, but tend to elastically deform when pressed by the mold, so they are patterned after removing the mold. The resin layer easily returns to its original shape. Therefore, in order to sufficiently plastically deform the resin layer, it is necessary to apply pressure for a long time.

  The present invention has been made in view of the above problems of the prior art, and an object thereof is to provide a method capable of easily forming a resin layer having a good pattern.

  The present invention comprises a step of pressing a mold having a concavo-convex pattern against a resin layer made of a resin composition containing a polymerizable unsaturated compound, and forming a pattern reversed on the concavo-convex pattern on the resin layer. The present invention relates to a method for producing a resin layer having The polymerizable unsaturated compound includes a (meth) acrylate compound having a urethane bond.

  According to the method of the present invention, a resin layer having a good pattern (hereinafter also referred to as “resin pattern”) can be easily formed.

  The method according to the present invention may further include a step of irradiating the resin layer with light before the step of forming the pattern on the resin layer. By this light irradiation, the releasability of the resin layer is enhanced, and the pattern can be formed more efficiently.

  The resin composition may further contain an inorganic filler. The combination of the inorganic filler and the (meth) acrylate compound having a urethane bond can significantly reduce the thermal expansion coefficient of the cured resin layer.

  The content of the inorganic filler may be 50 to 78% by mass with respect to the total amount of the resin composition. By setting it as the said range, the thermal expansion coefficient of the resin layer after hardening can be reduced significantly.

  The resin layer having a pattern obtained by the method of the present invention may be a permanent film.

  The resin composition may further contain a photopolymerization initiator. When the resin layer contains a photopolymerization initiator, the shape of the pattern is more easily retained when heated.

  The thermal expansion coefficient of the cured resin layer may be 30 ppm / ° C. or less at 50 to 100 ° C. By making the thermal expansion coefficient of a resin layer into the said range, the difference of the thermal expansion coefficient of a resin layer and a metal can be made smaller. As a result, when the resin layer is applied to a substrate formed with a metal circuit, for example, a substrate formed with copper (coefficient of thermal expansion: 18 ppm), the warpage of the substrate can be further suppressed. it can.

  In another aspect, the present invention relates to an imprint resin composition. The resin composition according to the present invention contains a polymerizable unsaturated compound including a (meth) acrylate compound having a urethane bond. The resin composition according to the present invention is a method for producing a resin layer having a pattern, comprising a step of pressing a mold having a concavo-convex pattern on the resin layer to form a pattern reversed on the concavo-convex pattern on the resin layer. Can be used to form the resin layer.

  Moreover, this invention also provides the resin film for imprints provided with the resin layer which consists of the resin composition for imprints concerning the said invention. The present invention also provides an electronic component having such a permanent film.

  According to the present invention, a resin layer having a good pattern can be easily formed. In particular, when the resin layer or the resin composition for imprinting contains an inorganic filler, high dimensional stability against temperature change, that is, low thermal expansion can be imparted to the resin layer having a pattern.

It is process drawing which shows one Embodiment of the method of manufacturing the resin layer which has a pattern. It is process drawing which shows one Embodiment of the method of manufacturing the resin layer which has a pattern. It is sectional drawing which shows one Embodiment of a semiconductor device provided with the resin layer which has a pattern as a permanent film.

  Hereinafter, preferred embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments.

<Method for producing resin layer having pattern>
FIG.1 and FIG.2 is process drawing which shows one Embodiment of the method of manufacturing the resin layer which has a pattern. The method shown in FIGS. 1 and 2 mainly includes a step of providing a resin layer 10a made of an imprinting resin composition on a substrate 1 (FIG. 1A) and a resin layer 10a on the substrate 1. And irradiating light (FIG. 1 (b)) and pressing the mold 5 having the concavo-convex pattern against the resin layer 10a irradiated with the light, the pattern reversed with respect to the pattern of the mold 5 is applied to the resin layer 10a. Steps of forming (FIGS. 1C and 1D), removing the mold 5 from the resin layer 10b on which the pattern is formed (FIG. 2E), and the resin layer 10b on which the pattern is formed It comprises a step of irradiating light ((f) in FIG. 2) and a step of thermally curing the resin layer 10b on which the pattern is formed ((g) in FIG. 2).

  As shown to (a) of FIG. 1, it is preferable that the resin layer 10a is formed by the method in which the film thickness becomes uniform. The preferred thickness of the resin layer 10a is about 1/3 to 2 times the height of the convex portion of the concave / convex pattern of the mold 5. When the resin layer 10a has an appropriate thickness, the resin composition is particularly easily filled in the uneven pattern, and the resin can be more effectively suppressed from remaining on the mold when the mold is removed from the resin layer. The thickness of the resin layer 10a is usually 1 to 100 μm, preferably 1 to 50 μm, more preferably 1 to 25 μm. The thickness of the resin layer 10a may be 15 μm or less. When the thickness of the resin layer 10a is particularly 15 μm or less, the remaining film thickness after imprinting (imprint) can be reduced while maintaining a good pattern shape. For example, when the height of the convex portion of the concavo-convex pattern of the mold 5 is 10 μm and L / S (line width / space width) = 5/5 μm, the remaining shape after the mold pressing is maintained while maintaining a good pattern shape. The film thickness can be about 0.1 to 10 μm.

  In the following description of the present specification, the expression “residual film” has a pattern by pressing the mold 5 having convex portions against the resin layer 10a and removing the mold 5 as shown in FIGS. When the resin layer 10b is formed, it is used as a term that defines a portion of the resin layer 10c corresponding to the convex portion of the mold 5. Further, the expression “residual film thickness” is used as a term that defines the thickness t of the resin layer 10c.

  The resin layer 10a can be formed, for example, by applying a resin composition for imprinting to the substrate 1. If necessary, the resin composition is dissolved or dispersed in a solvent to prepare a coating liquid, and the coating liquid is applied to the substrate 1 to form a coating film containing the resin composition and the solvent. The resin layer 10a may be formed by removing the solvent from the film. The method of application is not particularly limited, and for example, methods such as spin coating and dip coating can be used. Details of the resin composition for imprint will be described later.

  Alternatively, the resin layer 10a is formed in advance on the support film, and the imprint resin film having the support film and the resin layer 10a provided on the support film is prepared. The resin layer 10a can be provided on the substrate. Apply a resin composition for imprinting or a solution or dispersion thereof to a support film, and use a hot plate, oven, etc., for example, at 60 to 120 ° C. to dry the coating film by heating for 1 minute to 1 hour, The resin layer 10a can be formed on the support film. As the support film, for example, an organic film such as a polyethylene terephthalate film can be used. A protective film selected from a polyethylene terephthalate film, a polyethylene film, a polypropylene film, and the like may be laminated on the resin layer 10a. If the resin layer 10a has self-supporting properties, the support film can be peeled off and the resin layer 10a can be used alone as an imprinting resin film.

  In this case, the thickness of the resin layer 10a of the imprint resin film is usually 1 to 100 μm, preferably 1 to 50 μm, more preferably 1 to 25 μm. The thickness of the resin layer 10a may be 15 μm or less. When the thickness of the resin layer 10a is particularly 15 μm or less, for example, when a mold having an uneven pattern with a depth (or height) of 10 μm is used, the embossing (in) The remaining film thickness after printing can be reduced.

  After forming the resin layer 10 a on the substrate 1, as shown in FIG. 1B, the resin layer 10 a is irradiated with light (active light) from the side opposite to the substrate 1. This light irradiation can improve the mold release property on the surface of the resin layer 10a while maintaining the fluidity of the resin layer suitable for imprinting. As a result, after the mold 5 is pressed against the resin layer 10a to form a pattern on the resin layer 10a, the adhesion of the resin layer to the mold 5 is suppressed. Furthermore, the mold can be easily removed from the resin layer, and a resin layer having a better pattern can be obtained.

The type of light to be irradiated is not particularly limited. For example, at least one actinic ray selected from the group consisting of ultraviolet rays, visible rays, electron beams and X-rays is irradiated using a light source usually used in the field. The Among these, ultraviolet rays or visible rays are particularly preferable. Exposure, for example 1~4000mJ / cm ^2, preferably from 1 to 2,000 mJ / cm ^2, more preferably 1 to 100 mJ / cm ^2, more preferably in the range of 5~50mJ / cm ^2, the release resin layer Can be appropriately adjusted in consideration of a suitable balance between the property and fluidity. When the exposure amount is increased, the releasability of the resin layer is improved, and the fluidity of the resin layer tends to be lowered. In particular, when the resin layer 10a contains a polymerizable unsaturated compound, the resin layer 10a can be released and flowed by irradiating light with an exposure amount such that photopolymerization of the polymerizable unsaturated compound partially proceeds. A good balance of properties can be easily achieved.

  From the viewpoint of pattern formation efficiency, it is preferable to irradiate the resin layer 10a with light before pressing the mold 5 against the resin layer 10a. However, it is possible to secure the mold release property of the resin layer 10a to the extent that there is no practical problem. For example, this light irradiation is not always necessary.

  Next, as shown in FIGS. 1C and 1D, a mold 5 having a concavo-convex pattern inverted with respect to the pattern of the finally formed resin layer 10 is prepared, and this is pressed onto the resin layer 10a. Hit it. The method of pressing the mold is not particularly limited, and for example, a method of pressing the mold by hand, a method of pressing the mold at a high pressure using a press device, or the like can be used. As the mold 5, for example, a silicon mold can be used. The mold 5 does not necessarily need to be subjected to a release treatment, but may be subjected to a release treatment.

  When the mold 5 is pressed against the resin layer 10 a, the resin layer 10 a flows and fills the uneven pattern of the mold 5. Thereby, the resin layer 10b having a pattern inverted with respect to the concave / convex pattern of the mold 5 is formed. That is, the resin layer is patterned by imprinting using the mold 5. In the step of pressing the mold 5 against the resin layer 10a, it is preferable that the mold 5 is heated, particularly when the viscosity of the resin layer is high, in order to ensure good filling properties of the resin. The temperature of the mold 5 is preferably 40 ° C. or higher. Further, the temperature of the mold 5 is preferably 300 ° C. or lower for reasons such as preventing decomposition of the resin.

  The atmosphere when pressing the mold 5 against the resin layer is not particularly limited, but it is preferable to perform the step under reduced pressure in order to prevent bubbles from remaining in the resin layer. In particular, when the resin layer contains a polymerizable unsaturated compound having a carbon-carbon double bond such as a (meth) acryloyl group, an allyl group, or a vinyl group, the step is performed under reduced pressure in order to prevent polymerization inhibition due to oxygen. It is preferable.

  After the resin layer 10b having a pattern is formed, the mold 5 is removed from the resin layer 10b as shown in FIG.

  After the mold 5 is removed, the heat resistance, physical strength, and the like of the resin layer 10b can be increased by further curing the resin layer 10b. The resin layer 10b is heated by heating the resin layer 10b ((g) in FIG. 2, thermosetting), irradiating the resin layer 10b with light ((f) in FIG. 2, photocuring), or a combination thereof. It can be cured.

  The heating method for thermosetting is not particularly limited. For example, the formed pattern can be particularly easily held by gradually raising the temperature while maintaining the temperature below the glass transition point of the resin layer 10a. Moreover, the thermal decomposition of resin can be suppressed more by making the temperature of heating into 300 degrees C or less.

Photocuring can be performed by irradiating the resin layer 10b with active rays such as ultraviolet rays and visible rays in the same manner as the light irradiation before imprinting ((b) in FIG. 1). As light curing sufficiently proceeds, the exposure amount, for example 1~4000mJ / cm ^2, preferably adjusted within a range of 1000~4000mJ / cm ^2. This photocuring makes it difficult to soften the resin layer during thermosetting, and can more effectively prevent the pattern shape from collapsing. Therefore, the resin layer 10b is preferably photocured before thermosetting. The effect of pattern holding by photocuring is particularly prominent when the resin layer 10a contains a photopolymerization initiator. The fact that the shape of the pattern is easily maintained is particularly advantageous when, for example, a fine pattern is formed.

  When a residual film remains in the recess of the resin layer after imprinting, the residual film may be removed by dry etching. The dry etching process is not particularly limited as long as it is a commonly used method. For example, physical etching and reactive ion etching described in Japanese Patent No. 4257808 and Japanese Patent No. 4076889 can be used. .

<Imprint Resin Composition> (A) Polymerizable Unsaturated Compound The imprint resin composition according to this embodiment may contain (A) a polymerizable unsaturated compound. The polymerizable unsaturated compound may be, for example, a (meth) acrylate compound. As used herein, “(meth) acrylate compound” means an acrylate compound or a methacrylate compound. “(Meth) acryloyl group” means an acryloyl group or a methacryloyl group. The same applies to other terms similar to these.

  Since a resin composition containing a polymerizable unsaturated compound such as a (meth) acrylate compound can easily obtain higher fluidity than a polyimide resin, a resin layer having a good pattern can be formed. The resin composition according to this embodiment preferably includes a (meth) acrylate compound in which the polymerizable unsaturated compound has a urethane bond. When the polymerizable unsaturated compound includes a (meth) acrylate compound having a urethane bond, the strength of the resin pattern before curing is increased, and further, the resin layer before curing is applied to an adherend such as the substrate 1. Good adhesion can be imparted. As described above, a resin pattern such as a breakage of the resin pattern is caused by the strength of the resin pattern in the step of removing the mold from the resin layer after the mold having the uneven pattern is pressed against the resin layer and the resin pattern is formed. Defects can be suppressed. Furthermore, it can suppress that the said resin pattern peels from an adherend because the resin pattern before hardening has favorable adhesiveness to an adherend. Thereby, a resin layer having a good pattern can be obtained.

  Examples of the (meth) acrylate compound having a urethane bond include urethane (meth) acrylate and ethylene oxide (EO) -modified urethane di (meth) which are addition reaction products of a (meth) acrylic monomer having a hydroxyl group at the β-position and the like and a diisocyanate compound. Acrylate, ethylene oxide (EO) or propylene oxide (PO) modified urethane di (meth) acrylate, urethane (meth) acrylate having carboxy group, diol compound and two functional epoxy having two hydroxyl groups and two ethylenically unsaturated groups (meta ) It may be at least one selected from the group consisting of a reaction product of acrylate and polyisocyanate.

  The (meth) acrylic monomer having a hydroxyl group at the β-position is at least selected from the group consisting of 2-hydroxyethyl (meth) acrylate, dipentaerythritol penta (meth) acrylate, and pentaerythritol tri (meth) acrylate, for example. One kind may be sufficient. The isocyanate compound may be, for example, at least one selected from the group consisting of isophorone diisocyanate, 2,6-toluene diisocyanate, 2,4-toluene diisocyanate, and 1,6-hexamethylene diisocyanate.

  Optimize the number of functional groups (number of (meth) acryloyloxy groups) and weight average molecular weight of (meth) acrylate compounds with urethane bonds to achieve both higher levels of heat resistance, rigidity and high adhesion. Is preferred. Thereby, since the range of the material which can be selected without increasing a viscosity excessively becomes wide, the viscosity of the resin composition for imprint apply | coated on a board | substrate can be adjusted easily. Although the viscosity of the resin composition for imprint can be lowered by using a solvent, the amount of the solvent can be increased by using a (meth) acrylate compound having a urethane bond with an appropriate number of functional groups and weight average molecular weight. Can be reduced. By reducing the amount of the solvent, it is easy to maintain good characteristics and reliability of the cured resin layer.

  The number of functional groups (number of (meth) acryloyloxy groups) of the (meth) acrylate compound having a urethane bond is preferably 2 to 15 from the viewpoints of heat resistance, adhesion, coatability, and pattern formability. The number of functional groups is more preferably 2 to 12, and still more preferably 2 to 10 from the viewpoint of the physical properties of the resin layer after curing and the stability of characteristics.

  When the number of functional groups is 2 or more, the heat resistance of the cured resin layer and the rigidity of the resin layer at high temperatures can be further increased. When the number of the functional groups is 15 or less, the cured resin layer can be prevented from becoming brittle, and better adhesion can be obtained. Moreover, since the weight average molecular weight of a (meth) acrylate compound will not become large too much when the said functional group number is small, it is easy to adjust the viscosity of a resin composition to an appropriate range. Therefore, good coatability is easily obtained. Furthermore, a large amount of unreacted (meth) acryloyloxy groups remain after photocuring and / or heat curing, and as a result, it is possible to more effectively avoid fluctuations in physical properties and characteristics of the resin layer. it can.

  The weight average molecular weight (Mw) of the (meth) acrylate compound having a urethane bond is preferably 950 to 25000. The weight average molecular weight is more preferably 950 to 15000 from the viewpoint of improving coatability, and further preferably 950 to 11,000 from the viewpoint of compatibility. In the present specification, the value of the weight average molecular weight (Mw) means a value converted to standard polystyrene measured by a gel permeation chromatography craft (GPC) method using a developing solvent such as tetrahydrofuran and toluene. .

  When the weight average molecular weight is 950 or more, the viscosity of the resin composition does not become too low, and it is possible to prevent the resin composition applied on the substrate from dripping. Moreover, it is preferable that a weight average molecular weight is 950 or more also from the point that formation of a thick film is easy and the reliability fall resulting from hardening shrinkage does not occur easily. When the weight average molecular weight is 25000 or less, the viscosity of the resin composition does not become too high, and particularly good coatability is obtained. Moreover, thick film formation is also easy.

  The (meth) acrylate compound having a urethane bond is preferably a compound represented by the following general formula (1) from the viewpoints of heat resistance after curing, strength of the resin layer having a pattern, and adhesion.

R ₁ and R ₂ each independently represent a divalent organic group, for example, a linear or branched alkylene group having 1 to 15 carbon atoms, or an alicyclic group that may have a substituent, 1 to 1 carbon atoms. There are 20 groups. n is an integer greater than or equal to 1, for example, 1-5. In particular, from the viewpoint of improving the heat resistance after curing and the strength of the resin layer having a pattern, R ₂ is preferably a divalent group represented by the following structure.

［式中、ｎは５〜２０の整数を表す。］ Examples of (meth) acrylate compounds having a typical urethane bond include compounds represented by the following formula (2), (3), (4), (5) or (6). It is not limited.

[Wherein n represents an integer of 5 to 20. ]

［式中、ｎは５〜２０の整数を表す。］

[Wherein n represents an integer of 5 to 20. ]

［式中、ｎは５〜２０の整数を表す。］

[Wherein n represents an integer of 5 to 20. ]

［式中、ｎは５〜２０の整数を表す。］

[Wherein n represents an integer of 5 to 20. ]

［式中、ｎは５〜２０の整数を表す。］

[Wherein n represents an integer of 5 to 20. ]

  As a commercial item of the compound represented by the said general formula, UN-952 (the number of functional groups: 10, Mw: 6500-11000) etc. which are a compound represented by the said Formula (2) are mentioned, for example. Moreover, as a commercial item of the acrylate compound (compound which has acryloyloxy group) which has a urethane bond, UN-904 (functional group number: 10) which is an acrylate compound (compound which has acryloyloxy group) which has a urethane bond, for example. Mw: 4900), UN-952 (functional group number: 10, Mw: 6500 to 11000), UN-333 (functional group number: 2, Mw: 5000), UN-1255 (functional group number: 2, Mw: 8000), UN -2600 (functional group number: 2, Mw: 2500), UN-6200 (functional group number: 2, Mw: 6500), UN-3320HA (functional group number: 6, Mw: 1500), UN-3320HC (functional group number: 6, Mw: 1500), UN-9000 PEP (functional group number: 2, Mw: 5000), UN-9200A ( No. of functional groups: 2, Mw: 15000), UN-3320HS (functional groups: 15, Mw: 4900), UN-6301 (functional groups: 2, Mw: 33000) (all are trade names, Negami Industrial Co., Ltd.) , TMCH-5R (trade name, Hitachi Chemical Co., Ltd.), KRM8452 (functional group number = 10, Mw = 1200), EBECRYL8405 (urethane acrylate / 1,6-hexanediol diacrylate = 80/20 addition reaction product, functional group number : 4, Mw: 2700) (all are trade names, Daicel-Cytec Co., Ltd.).

  Examples of the methacrylate compound having a urethane bond (compound having a methacryloyloxy group) include UN-6060PTM (functional group number: 2, Mw: 6000, trade name, Negami Industrial Co., Ltd.), JTX-0309 (trade name, Hitachi Chemical) Co., Ltd.), UA-21 (trade name, Shin-Nakamura Chemical Co., Ltd.).

  From the viewpoint of improving heat resistance, the content of the (meth) acrylate compound having a urethane bond is preferably 10% by mass or more, more preferably 30% by mass, based on the total amount of the polymerizable unsaturated compound of the component (A). % Or more, more preferably 50 mass% or more. When the content is 10% by mass or more, various physical properties and characteristics required for coating properties and a cured product of the resin composition can be maintained at a higher level.

  In view of the coating properties of the resin composition and the physical properties and properties required for the cured product of the resin composition, in order to selectively blend other (meth) acrylate compounds described later, a urethane bond ( The content of the (meth) acrylate is preferably 95% by mass or less, more preferably 85% by mass or less, and still more preferably 75% by mass or less, with respect to the total amount of the polymerizable unsaturated compound (A).

  The resin composition may contain (meth) acrylate compounds other than the (meth) acrylate compound which has a urethane bond as a polymerizable unsaturated compound. This (meth) acrylate compound includes, for example, a (meth) acrylate compound having an amide bond, a compound obtained by reacting a polyhydric alcohol with an α, β-unsaturated carboxylic acid, a bisphenol A (meth) acrylate compound, glycidyl. It contains at least one selected from the group consisting of a compound obtained by reacting a group-containing compound with an α, β-unsaturated carboxylic acid, and a (meth) acrylic acid alkyl ester copolymer having an ethylenically unsaturated group. .

Among these, a (meth) acrylate compound having an amide bond is preferable in terms of increasing the tolerance of the imprint process in addition to improving heat resistance and adhesion. The tolerance of the imprint process means an allowable range of various conditions such as temperature and exposure amount in the imprint process. The (meth) acrylate compound having an amide bond is preferably a compound represented by the following general formula (7) from the viewpoint of resolution and adhesion. In formula (7), R ³¹ , R ³² and R ³³ each independently represent a divalent organic group, R ³⁴ represents a hydrogen atom or a methyl group, and R ³⁵ and R ³⁶ each independently represent hydrogen. An atom, an alkyl group having 1 to 4 carbon atoms or a phenyl group is shown.

The divalent organic group as R ³¹ , R ³² or R ³³ is, for example, a phenylene group which may have a substituent, a pyridylene group which may have a substituent, a linear chain having 1 to 10 carbon atoms, or A branched alkylene group, a group having 1 to 10 carbon atoms including an alicyclic group which may have a substituent, or a hydroxyl group from bisphenol (such as 2,2-bis (4-hydroxy-3,5-dichlorophenyl) propane) Is a group formed by removing

  The compound represented by the general formula (7) can be obtained, for example, by reacting a compound having two oxazoline groups with a compound having two carboxy groups and / or a compound having two phenolic hydroxyl groups. . Thereby, a high elastic modulus and high heat resistant resin cured product is particularly easily formed.

Examples of the compound containing an oxazoline group used for synthesizing the compound represented by the formula (7) include a bisoxazoline represented by the following general formula (8). In the formula ^(8), R ^{33, R 35} and ^{R 36} have the same meanings as ^{R 33, R 35} and ^{R 36} in the formula (7).

  Examples of the bisoxazoline represented by the formula (8) include 2,2 ′-(1,3-phenylene) bis-2-oxazoline and 2,6-bis (4-isopropyl-2-oxazolin-2-yl). At least one selected from the group consisting of pyridine, 2,2′-isopropylidenebis (4-phenyl-2-oxazoline), and 2,2′-isopropylidenebis (4-tertiarybutyl-2-oxazoline) is there.

Examples of the compound having two phenolic hydroxyl groups (bisphenol) include biphenol, tetramethylbiphenol, dihydroxynaphthalene, dihydroxymethylnaphthalene, dihydroxydimethylnaphthalene, bis (4-hydroxyphenyl) ketone, and bis (4-hydroxy-3,5). -Dimethylphenyl) ketone, bis (4-hydroxy-3,5-dichlorophenyl) ketone, bis (4-hydroxyphenyl) sulfone, bis (4-hydroxy-3,5-dimethylphenyl) sulfone, bis (4-hydroxy- 3,5-dichlorophenyl) sulfone, bis (4-hydroxyphenyl) hexafluoropropane, bis (4-hydroxy-3,5-dimethylphenyl) hexafluoropropane, bis (4-hydroxy-3,5-dichlorophenyl) Nyl) hexafluoropropane, bis (4-hydroxyphenyl) dimethylsilane, bis (4-hydroxy-3,5-dimethylphenyl) dimethylsilane, bis (4-hydroxy-3,5-dichlorophenyl) dimethylsilane, bis (4 -Hydroxyphenyl) methane, bis (4-hydroxy-3,5-dichlorophenyl) methane, bis (4-hydroxy-3,5-dibromophenyl) methane, 2,2-bis (4-hydroxyphenyl) propane, 2, 2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 2,2-bis (4-hydroxy-3,5-dichlorophenyl) propane, 2,2-bis (4-hydroxy-3-methylphenyl) Propane, 2,2-bis (4-hydroxy-3-chlorophenyl) propane, bis (4- Droxyphenyl) ether, bis (4-hydroxy-3,5-dimethylphenyl) ether, bis (4-hydroxy-3,5-dichlorophenyl) ether, 9,9-bis (4-hydroxyphenyl) fluorene, 9-bis (4-hydroxy-3-methylphenyl) fluorene, 9,9-bis (4-hydroxy-3-chlorophenyl) fluorene, 9,9-bis (4-hydroxy-3-bromophenyl) fluorene, 9, 9-bis (4-hydroxy-3-fluorophenyl) fluorene, 9,9-bis (4-hydroxy-3-methoxyphenyl) fluorene, 9,9-bis (4-hydroxy-3,5-dimethylphenyl) fluorene 9,9-bis (4-hydroxy-3,5-dichlorophenyl) fluorene, and 9,9-bis (4- It may be at least one selected from the group consisting of (hydroxy-3,5-dibromophenyl) fluorene. Among these, 2,2-bis (4-hydroxy-3,5-dichlorophenyl) propane is preferable. R ³¹ in formula (7) is usually a residue obtained by removing a hydroxyl group from a compound having these two phenolic hydroxyl groups.

  The reaction between the compound having an oxazoline group and the compound having a carboxy group and / or the compound having a phenolic hydroxyl group is preferably performed at 50 to 200 ° C. If reaction temperature is 50 degreeC or more, reaction can be advanced efficiently, and if it is 200 degrees C or less, a side reaction can fully be suppressed. If necessary, the reaction may be carried out in a polar organic solvent such as dimethylformamide, dimethylacetamide, dimethylsulfoxide.

  Examples of the compound obtained by reacting a polyhydric alcohol with an α, β-unsaturated carboxylic acid include, for example, polyethylene glycol di (meth) acrylate having 2 to 14 ethylene groups and 2 to 14 propylene groups. Polypropylene glycol di (meth) acrylate, polyethylene polypropylene glycol di (meth) acrylate having 2 to 14 ethylene groups and 2 to 14 propylene groups, trimethylolpropane di (meth) acrylate, trimethylol Propane tri (meth) acrylate, ethylene oxide (EO) modified trimethylolpropane tri (meth) acrylate, propylene oxide (PO) modified trimethylolpropane tri (meth) acrylate, EO and PO modified trimethylolpropane tri (meth) acrylate Or at least one selected from the group consisting of tetramethylolmethane tri (meth) acrylate, tetramethylolmethanetetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, and dipentaerythritol hexa (meth) acrylate Good.

  Examples of bisphenol A-based (meth) acrylate compounds include 2,2-bis (4-((meth) acryloxypolyethoxy) phenyl) propane and 2,2-bis (4-((meth) acryloxypolypropoxy). Phenyl) propane, 2,2-bis (4-((meth) acryloxypolybutoxy) phenyl) propane, and 2,2-bis (4-((meth) acryloxypolyethoxypolypropoxy) phenyl) propane It may be at least one selected from the group.

  The compound obtained by reacting a glycidyl group-containing compound with an α, β-unsaturated carboxylic acid is, for example, at least one epoxy selected from the group consisting of a novolac type epoxy resin, a bisphenol type epoxy resin and a salicylaldehyde type epoxy resin The epoxy (meth) acrylate compound obtained by making resin and (meth) acrylic acid react may be sufficient.

  An acid-modified epoxy acrylate compound obtained by reacting an acid anhydride such as tetrahydrophthalic anhydride with the hydroxyl group of the epoxy (meth) acrylate compound can also be used as the polymerizable unsaturated compound. As such an acid-modified epoxy acrylate compound, for example, EA-6340 (Shin Nakamura Chemical Co., Ltd., trade name) represented by the following general formula (9) is commercially available. In formula (9), m and n represent 0 or an integer of 1 or more, and the ratio of m to n is 100/0 to 0/100.

  Examples of the (meth) acrylic acid alkyl ester copolymer having an ethylenically unsaturated group include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, and (meth) acrylic acid 2- At least one (meth) alkyl acid ester selected from the group consisting of ethylhexyl is included as a monomer unit.

  The (meth) acrylate compound used as the polymerizable unsaturated compound of component (A) preferably has a carbon-nitrogen bond and has a amide bond from the viewpoint of improving heat resistance and adhesion. And / or (meth) acrylate compounds having a urethane bond are more preferred.

  The resin composition has a (meth) acrylate compound having an amide bond and a urethane bond from the viewpoint of improving the adhesion density by increasing the crosslink density, increasing the tolerance of the imprint process, and balancing heat resistance. It is preferable to contain a (meth) acrylate compound. In this case, the ratio of (meth) acrylate compound having urethane bond to (meth) acrylate compound having amide bond ((meth) acrylate compound having urethane bond / (meth) acrylate compound having amide bond, mass ratio) is , Preferably 40/60 to 90/10, more preferably 50/50 to 85/15, still more preferably 60/40 to 80/20.

(B) Photopolymerization initiator The resin composition for imprints according to this embodiment may contain a photopolymerization initiator. Thereby, a polymerizable unsaturated compound can be bridge | crosslinked efficiently by light irradiation and the viscoelasticity of a resin layer can be easily adjusted to the range suitable for an imprint process. When the resin layer is heat-cured after the imprint process, depending on the heating conditions, the resin may melt and the pattern may sag and deform, but the resin composition contains a photopolymerization initiator, and patterning is possible. Since the polymerizable unsaturated compound can be efficiently cured by subsequent light irradiation, it is possible to more effectively suppress the deterioration of the pattern shape (pattern droop) associated with thermosetting.

  The photopolymerization initiator is not particularly limited as long as it is a compound that generates a free radical by actinic rays. For example, acylphosphine oxide, oxime ester, aromatic ketone, quinones, benzoin ether compound, benzyl derivative, 2, 4 , 5-triarylimidazole dimer, acridine derivative, coumarin compound, N-phenylglycine, and at least one selected from the group consisting of N-phenylglycine derivatives. Among these, acylphosphine oxide or oxime ester is preferable from the viewpoint of improvement of photocurability, high sensitivity, and transparency of the cured film.

  As said photoinitiator, the photoinitiator described in the international publication 2013/077358 can be used, for example.

  The content of the photopolymerization initiator is preferably 0.1 to 20 parts by mass, more preferably 0.5 to 10 parts by mass, and still more preferably, with respect to 100 parts by mass of the polymerizable unsaturated compound (A). 0.75 to 5 parts by mass. When the content is within these ranges, the sensitivity and photocurability of the imprint resin composition are particularly enhanced, and the adjustment of the viscoelasticity of the resin layer and the retention of the pattern shape during thermosetting are further facilitated. Become.

(C) Inorganic filler The resin composition for imprints according to this embodiment may contain an inorganic filler. The inorganic filler can adjust the fluidity of the resin composition for imprinting, and can increase the process tolerance when it is formed into a film. Further, the combination of the (meth) acrylate compound having a urethane bond as the component (A) and the inorganic filler can specifically and significantly reduce the thermal expansion coefficient of the cured resin layer. When forming a resin layer having a pattern by photolithography, it is generally difficult to contain an inorganic filler in the resin layer, but according to the imprint method, a resin layer containing an inorganic filler can be easily patterned. it can.

  The shape of the inorganic filler may be any of a spherical shape, a crushed shape, a needle shape, or a plate shape, and a desired shape can be selected according to the particle diameter or the like. The volume average particle diameter of the inorganic filler is preferably in the range of 10 nm to 50 μm. As the inorganic filler, silica, alumina or the like can be preferably used. For example, a small particle diameter inorganic filler having a spherical or nearly spherical shape with a volume average particle diameter in the range of 10 nm to 1 μm not only increases the elastic modulus at a high temperature of the resin composition for imprinting, but also of a cured product. Mechanical strength can be improved. Furthermore, the effect of imparting thixotropy to the imprinted resin composition before curing and improving the coating property can also be obtained. Therefore, an inorganic filler having a small particle diameter is suitable when it is desired to further improve the physical properties and characteristics of the resin composition without substantially affecting the light transmission and light absorption. A large particle size inorganic filler having a volume average particle size in the range of 1 μm to 50 μm can greatly increase the elastic modulus of the resin composition for imprints at a high temperature, so it has a great effect on pattern shape retention. Can be demonstrated.

  When the volume average particle diameter of the inorganic filler is 10 nm or more, the inorganic filler hardly aggregates in the resin composition, and the inorganic filler can be easily and uniformly dispersed. Therefore, a fine pattern can be easily formed, and in addition, variations in physical properties and characteristics of the cured product of the resin composition can be reduced. The volume average particle diameter of the inorganic filler is more preferably 50 nm or more. Furthermore, if the volume average particle diameter of the inorganic filler is 1 μm or more, the resin composition can be easily formed into a film even if the filler is highly filled in the resin, and the laminate can be used without any problem. Can do. When the volume average particle diameter of the inorganic filler is 50 μm or less, the cured product of the resin composition can be prevented from becoming brittle, and it becomes easier to form a fine pattern.

  The volume average particle diameter of the inorganic filler is more preferably smaller than the width and height of the pattern formed by the imprint method. The preferred volume average particle diameter depends on the pattern to be formed, but is 10 nm to 5 μm from the viewpoint of the fine pattern formability. Furthermore, the volume average particle diameter of the inorganic filler is more preferably 1 μm to 5 μm from the viewpoint of laminating properties when formed into a film, fine pattern formability, and mechanical strength of the cured product, and 1.5 μm to 4 μm. More preferably, it is more preferably over 2 μm.

  The volume average particle diameter of the inorganic filler can be obtained as a MV value (Mean Volume Diameter: volume average value) using a laser diffraction particle size distribution meter (for example, Nikkiso Co., Ltd., trade name: Microtrack MT3000). The volume average particle diameter of the inorganic filler can be measured by using a test solution prepared by dispersing phosphinates as a dispersant and dispersing the inorganic filler in water.

  Commercially available inorganic fillers having the volume average particle diameter as described above may be used as they are, or a combination of a plurality of commercially available products and / or a method of classifying the commercially available products by sieving, etc. An inorganic filler having a volume average particle diameter may be prepared.

  When the inorganic filler is contained, the content thereof is preferably 0.1 to 500 parts by mass, more preferably 40 to 400 parts by mass with respect to 100 parts by mass of the polymerizable unsaturated compound (A). is there. From the viewpoint of improving the mechanical strength of the cured product and specifically reducing the thermal expansion coefficient of the cured resin layer, the content of the inorganic filler is more preferably 100 to 350 parts by mass.

  When the content of the inorganic filler is 500 parts by mass or less with respect to 100 parts by mass of the polymerizable unsaturated compound (A), the resin composition suppresses a decrease in fluidity of the resin composition due to the addition of the filler. An object can be more easily formed into a film. When the content of the inorganic filler is 1 part by mass or more, the fluidity of the resin composition can be lowered, and the repellency on the surface of the support film can be reduced, so the resin composition can be more easily formed into a film. Tend to be able to.

  The content of the inorganic filler with respect to the total amount of the resin composition is preferably 1 to 85% by mass, more preferably 25 to 80% by mass, still more preferably 50 to 78% by mass, and 60 to 78%. It is particularly preferable that the content is% by mass. By making the content rate of an inorganic filler into the said range, the thermal expansion coefficient of the resin layer after hardening can be reduced significantly. By making the content rate of an inorganic filler 85 mass% or less, since the fall of the fluidity | liquidity of the resin composition by filler addition can be suppressed more, a resin composition can be easily shape | molded in a film form. By setting the content of the inorganic filler to 1% by mass or more, the repellency on the surface of the support film can be reduced, so that the resin composition can be easily formed into a film. Especially, by making the content rate of an inorganic filler 50-78 mass%, the mechanical strength of hardened | cured material can be improved and the thermal expansion coefficient of the resin layer after hardening can be reduced specifically, 60-78 By setting it as the mass%, the said effect can be show | played more notably.

  The surface of the inorganic filler may be surface-treated with an organic group, and examples of the organic group include an epoxy group, a phenyl group, and a methacryl group. Thereby, aggregation of an inorganic filler can be suppressed more.

  The resin composition for imprints of the present embodiment has a polymerizable functional group ((meth) acryloyl) of a polymerizable unsaturated compound after pattern formation for the purpose of maintaining the shape of the formed pattern or improving film characteristics. The polymerization reaction of an oxy group or the like can be further advanced. When polymerizing a polymerizable functional group by heat, the resin composition may contain one or more thermal radical polymerization initiators such as organic peroxides and azo compounds.

  As said thermal radical polymerization initiator, the thermal radical polymerization initiator described in the international publication 2013/077358 and the international publication 2008/105309 can be used, for example.

  When it contains a thermal radical polymerization initiator, the content thereof is preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the polymerizable unsaturated compound (A).

(Other ingredients)
The imprinting resin composition may contain an adhesion aid as necessary in order to improve the adhesion between the imprinting resin composition and the substrate. Examples of the adhesion assistant include silane coupling agents such as γ-glycidoxysilane, aminosilane, and γ-ureidosilane. The content of the adhesion assistant is preferably 0.1 to 10 parts by mass, more preferably 0.2 to 5 parts by mass, and still more preferably 0 with respect to 100 parts by mass of the polymerizable unsaturated compound (A). .5 to 2 parts by mass.

  From the viewpoint of workability when applied to a substrate, a support film or the like, a solvent or a dispersion of the resin composition may be added as a coating liquid by adding a solvent to the resin composition for imprint. The solvent to be used is not particularly limited, but includes, for example, polar solvents such as N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, propylene glycol monomethyl ether acetate, and γ-butyrolactone. It may be at least one selected from the group. The concentration of the resin composition for imprint in the coating solution is preferably 20 to 85% by mass, more preferably 30 to 80% by mass, based on the mass of the coating solution.

  The resin composition according to the present embodiment can be suitably used for producing a resin layer having a pattern. That is, according to this embodiment, the application for manufacturing the resin layer which has a pattern of a resin composition is provided.

<Electronic parts>
The electronic component according to the present embodiment includes a resin layer (cured film) having a pattern formed by the above-described method as a permanent film. The electronic component may be, for example, a semiconductor device, a multilayer wiring board, various electronic devices, or the like.

  The “permanent film” is a film constituting an electronic component or the like as a finished product without being removed in the process of manufacturing the electronic component or the like. Specific examples of the permanent film include a surface protective layer and an interlayer insulating layer of an electronic component, and an interlayer insulating layer of a multilayer wiring board. The electronic component according to the present embodiment is not particularly limited as long as it has a permanent film formed by the method according to the present embodiment.

  FIG. 3 is a cross-sectional view showing an embodiment of a semiconductor device provided with a resin layer having a pattern as a permanent film. A semiconductor device 100 shown in FIG. 3 includes a silicon chip 23, an interlayer insulating layer 11 provided on one surface side of the silicon chip 23, and an Al having a pattern including a pad portion 15 formed on the interlayer insulating layer 11. A wiring layer 12, an insulating layer 13 (for example, a P-SiN layer) and a surface protective layer 14, which are sequentially stacked on the interlayer insulating layer 11 and the Al wiring layer 12 while forming an opening on the pad portion 15, and a surface protective layer 14 is in contact with the pad portion 15 in the openings of the insulating layer 13 and the surface protective layer 14 and is opposite to the surface protective layer 14 of the core 18 for the rewiring layer. And a rewiring layer 16 extending on the surface protective layer 14 so as to be in contact with the surface. Further, the semiconductor device 100 includes a cover coat layer 19 that covers the surface protective layer 14, the rewiring core 18 and the rewiring layer 16, and forms an opening in the rewiring layer 16 portion on the core 18. The conductive ball 17 connected to the rewiring layer 16 with the barrier metal 20 interposed therebetween in the opening of the layer 19, the collar 21 that holds the conductive ball, and the cover coat layer 19 around the conductive ball 17 are provided. The underfill 22 is provided. The conductive ball 17 is used as an external connection terminal and is formed of solder, gold or the like. The underfill 22 is provided to relieve stress when the semiconductor device 100 is mounted.

  In the semiconductor device 100, at least one permanent film selected from the group consisting of the interlayer insulating layer 11, the surface protective layer 14, the cover coat layer 19, the rewiring core 18, the collar 21, and the underfill 22 is the resin composition described above. It is a permanent film that can be formed by an object. The cured film formed by the resin composition for imprinting according to the present embodiment is excellent in adhesiveness with a metal layer and a sealant and has a high stress relaxation effect. Therefore, the semiconductor device 100 has extremely excellent reliability. The semiconductor device according to the present invention is not limited to the one having the structure shown in FIG.

  For example, the interlayer insulating layer 11 in FIG. 3 can be formed as follows. On the silicon chip 23 on which the circuit is formed, the resin composition for imprinting according to the present embodiment is provided so that the steps are embedded, and a resin layer is formed. Thereafter, a mold having projections and depressions is prepared, and a concave portion is provided in the resin layer by pressing the surface having projections and depressions toward the resin layer side and removing the mold. Then, the resin layer which has the formed recessed part is thermosetted by performing heat processing. Here, a residual film may remain in the concave portion of the resin layer. In this case, by performing a dry etching process, the residual film of the concave portion can be removed, and an opening that penetrates the concave portion is obtained. Can do. The dry etching process can also be performed after providing an etching protective film. As described above, the interlayer insulating layer 11 can be obtained.

  In order to make the interlayer insulating layer 11, the surface protective layer 14, the cover coat layer 19, the rewiring core 18, the ball collar 21 such as solder, the underfill 22, etc. more reliable, the resin composition for imprinting The thermal expansion coefficient at 50 to 100 ° C. after curing of the product is preferably 50 ppm / ° C. or less, more preferably 30 ppm / ° C. or less. By including an appropriate amount of inorganic filler in the imprinting resin composition used to form the permanent film, the thermal expansion coefficient can be significantly reduced.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples.

<Synthesis of polyimide resin (for comparative example)>
11.52 g (36 mmol) of 2,2′-bis (trifluoromethyl) -4,4′-diaminobiphenyl was dissolved in 66.4 g of N-methyl-2-pyrrolidone. Thereafter, 8.72 g (40 mmol) of pyromellitic dianhydride was added to proceed the polymerization, and a solution of the produced polyamic acid (polyimide resin I) was obtained. The weight average molecular weight of the polyamic acid determined by standard polystyrene conversion was 44900.

<Preparation of resin composition for imprint>
The (meth) acrylate compound as the component (A), the photopolymerization initiator as the component (B), the inorganic filler as the component (C), and other components in N, N-dimethylacetamide as a solvent are shown in Table 1. Or it mixed in the ratio shown in Table 2, and the solution of the resin composition for imprints of each Example and a comparative example was obtained. The numbers in the table indicate the mass parts of the solid content of each component. The detail of each component in a table | surface is shown below.
(A) Component: (Meth) acrylate compound Urethane compound having (meth) acryloyloxy group-UN-904, UN-952, UN-333, UN-3320HA, UN-3320HS (trade name, urethane acrylate, hydroxyl group-containing (meth) acrylic monomer and diisocyanate compound Addition reaction product, Negami Industrial Co., Ltd.)
2. Other (meth) acrylate compounds FA-7220M (trade name, amide bond-containing methacrylate represented by formula (7), Hitachi Chemical Co., Ltd.)
・ EA-6340 (trade name, tetrahydrophthalic anhydride-modified vinyl group-containing phenol type epoxy resin, Shin-Nakamura Chemical Co., Ltd.)
・ BPE-100 (trade name, ethoxylated bisphenol A dimethacrylate, Shin-Nakamura Chemical Co., Ltd.)
・ Polyamide acid (polyimide resin) synthesized above
Component (B): Photopolymerization initiator / I-819 (trade name, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, Ciba Specialty Chemicals Co., Ltd.)
I-OXE01 (trade name, 1,2-octanedione-1- [4- (phenylthio) phenyl] -2- (O-benzoyloxime, Ciba Specialty Chemicals Co., Ltd.)
・ Dicumyl peroxide (trade name, Park Mill D, Nippon Oil & Fat Co., Ltd. (thermal radical polymerization initiator)
(C) component: inorganic filler silica A (spherical silica, volume average particle diameter 3.6 μm, CIK Nanotech Co., Ltd.)
・ Silica B (spherical silica, volume average particle size 1.5 μm, Tatsumori Co., Ltd.)
・ Silica C (spherical silica, volume average particle size 0.5 μm, Tatsumori Co., Ltd.)
Other components ・ Epicron N-865 (trade name, polyfunctional bisphenol A novolac type epoxy resin, Dainippon Ink & Chemicals, Inc.)
AY43-031 (trade name, silane coupling agent, Toray Dow Corning Co., Ltd.)

Tables 1 and 2 show the number of urethane acrylate functional groups (acryloyloxy groups) and the weight average molecular weight. The weight average molecular weight (Mw) is determined by GPC method using tetrahydrofuran and N, N-dimethylacetamide as an eluent. Details of the GPC method are as follows.
Device name: HLC-8320GPC (product name, Tosoh Corporation)
Column: TSKgel Super AWM-H, TSK gel guard column Super A W-H, TSK gel Super H 2500, TSK gel Super H 3000, TSK gel Super H 4000, TSK gel guard column Super H, H all L
Detector: UV, RI detector Column temperature: 40 ° C
Eluent: Mixed solution of tetrahydrofuran and N, N-dimethylacetamide (mixing ratio 1: 1)
Additives: lithium bromide monohydrate (0.03 mol / L), phosphoric acid (0.06 mol / L)
Flow rate: 0.35 ml / min Standard material: Polystyrene

<Preparation of resin film for imprint>
The solution of the resin composition for imprint of an Example and a comparative example was apply | coated uniformly using the applicator on the polyethylene terephthalate as a support film. The coated solution is heated for 30 minutes with a 120 ° C. dryer to remove the solvent, thereby forming a resin layer for imprinting, and having a support film and a resin layer formed on the support film A resin film for imprinting was obtained. The resin layer thickness of the obtained resin film for imprinting was 24 μm.

<Evaluation of pattern formability>
On the test substrate, the resin film for imprint was laminated in such a direction that the support film was located on the opposite side of the test substrate. Lamination was performed using a laminator. The resin film for imprint laminated on the test substrate was irradiated with light at an exposure amount of 100 mJ / cm ² using a high-precision parallel exposure machine (Oak Manufacturing Co., Ltd.) (light irradiation before imprinting).

Next, after peeling off the support film, the resin layer is placed on a silicon mold (height 10 μm, L / S (line width / space width) = 5/5 μm) together with the test substrate, and these are put on a crimping machine. It was set and pressurized while heating to 60 ° C. (Examples 1 to 6) or 100 ° C. (Examples 7 to 14) at 8 MPa for 2 minutes. After pressurization, the mold was removed from the resin layer, the coating of the resin layer having a pattern was observed using a scanning electron microscope, and the pattern forming property was evaluated based on the following criteria.
A: The resin pattern remained in the mold, and a good pattern was formed.
B: Resin partially remains in the mold, and chipping can be confirmed in the pattern (resin pattern chipping).
C: Most of the resin remains in the mold, and pattern formation is difficult (break of the resin pattern).
D: The mold does not peel from the resin layer.
E: When the mold is removed, the pattern is deformed and it is difficult to form the pattern.

<Evaluation of pattern retention>
Similar to the evaluation of pattern formation, an imprinting resin film was laminated on the test substrate. Next, after peeling off the support film, the resin layer is placed on a silicon mold (height 10 μm, L / S = 5/5 μm) together with the test substrate, and these are set on a crimping machine, and 2 at 8 MPa. Pressurize with heating to 60 ° C. (Examples 1 to 6) or 100 ° C. (Examples 7 to 14) for 5 minutes. After pressurization, the mold was removed from the resin layer, and then the resin layer on which the pattern was formed was irradiated with light at an exposure amount of 4000 mJ / cm ² using a high-precision parallel exposure machine (Oak Manufacturing Co., Ltd.). After the exposure, the temperature was raised from room temperature to 200 ° C. at 2.8 ° C./min in an oven, and then the resin layer was thermally cured by heating at 200 ° C. for 1 hour.

The cured resin layer (cured film) was observed using a scanning electron microscope, and pattern retention was evaluated based on the following criteria.
A: The resin layer is not melted and the shape is maintained (the shape change is within 10%).
B: Shape change due to melting is observed.

<Evaluation of remaining film thickness>
Similar to the evaluation of pattern formation, an imprinting resin film was laminated on the test substrate. Next, after peeling off the support film, the resin layer is placed on a silicon mold (height 10 μm, L / S = 5/5 μm) together with the test substrate, and these are set on a crimping machine, and 2 at 8 MPa. The pressure was applied while heating to 100 ° C. (Examples 1 to 6) or 140 ° C. (Examples 7 to 14) for minutes. After pressurization, the mold was removed from the resin layer, and the resin layer on which the pattern was formed was observed using a scanning electron microscope. The remaining film thickness was evaluated based on the following criteria.
A: The remaining film thickness is 0 μm or more and less than 1 μm.
B: The remaining film thickness is 1 μm or more and less than 10 μm.
C: The remaining film thickness is 10 μm or more.
D: Evaluation is impossible.

<Coefficient of thermal expansion (CTE)>
The average thermal expansion coefficient at 50 to 100 ° C. of the cured resin layer was measured as shown below. Device name: Thermomechanical analyzer (with stress strain measurement function) TMA / SS6000 (product name, Seiko Instruments Inc.)
Sample preparation conditions Sample size: length 30 mm × width 2 mm × thickness 100 μm
Exposure amount: 4000 mJ / cm ²
Curing conditions: The resin layer was exposed under the above exposure conditions, heated from 30 ° C. to 200 ° C. at 2.8 ° C./min, and then cured at 200 ° C. for 1 hour, and the following temperature conditions were used. Measured with.
Temperature: 30-300 ° C
Load: 500mPa

<Glass transition temperature>
The glass transition temperature of the cured resin layer was measured by a method in which extrapolation points before and after the inflection point obtained with a thermomechanical analyzer (TMA) were used as the glass transition temperature. The glass transition temperature by TMA is a point (inflection point) at which the linear expansion coefficient changes discontinuously, and is obtained by a method in which extrapolation points before and after the inflection point are used as the glass transition temperature.

  Table 3 shows the evaluation results. The resin composition for imprinting of Examples containing a (meth) acrylate compound having a urethane bond as a (meth) acrylate compound was pressed against a resin layer with a mold having an uneven pattern, and a resin layer having a pattern was formed. Later, in the step of removing the mold from the resin layer, defects in the resin layer having a pattern did not occur, and the resin layer did not peel from the test substrate, indicating excellent pattern formability. Furthermore, according to the resin composition of Examples 1-5 and 8-14 which mix | blended the photoinitiator, the characteristic outstanding also in the point of pattern retainability was acquired.

  When an epoxy resin is used instead of the (meth) acrylate compound having a urethane bond as in Comparative Examples 1 and 2, the strength of the resin layer having the pattern is insufficient, and it is suitable for the imprint process by light irradiation. Therefore, it was difficult to adjust the viscoelasticity, so that the releasability was not improved and pattern formation was difficult. Moreover, in these comparative examples, as a result of evaluating the pattern retention of the resin layer obtained by applying a very strong force to remove from the mold, it was not possible to prevent the resulting resin layer from melting due to thermosetting, Retention was not sufficient.

  When using only a (meth) acrylate compound other than a (meth) acrylate compound having a urethane bond as in Comparative Examples 3 and 4, it is difficult to remove the resin layer from the mold, and the resin layer peels off from the test substrate. There were many parts. Moreover, it was difficult to maintain the pattern shape under the severe conditions of high-temperature heating.

  Further, when an epoxy resin is used instead of the (meth) acrylate compound as in Comparative Examples 1 and 2, the effect of reducing the coefficient of thermal expansion due to the addition of the inorganic filler is small, whereas it has a urethane bond (meta In the case of Examples using acrylate compounds, it was also confirmed that the thermal expansion coefficient was specifically reduced by the addition of an inorganic filler.

  DESCRIPTION OF SYMBOLS 1 ... Substrate, 5 ... Mold, 10 ... Resin layer (cured film) having a pattern, 10a ... Resin layer, 10b ... Resin layer having a pattern, 10c ... Resin layer corresponding to convex part of mold 5 (residual film) 11 ... interlayer insulating layer, 12 ... Al wiring layer, 13 ... insulating layer, 14 ... surface protective layer, 15 ... pad portion, 16 ... re-wiring layer, 17 ... conductive ball, 18 ... core, 19 ... cover coat Layer: 20 ... Barrier metal, 21 ... Color, 22 ... Underfill, 23 ... Silicon chip, 100 ... Semiconductor device (electronic component).

Claims (16)

A step of pressing a mold having a concavo-convex pattern against a resin layer made of a resin composition containing a polymerizable unsaturated compound, and forming a pattern reversed with respect to the concavo-convex pattern on the resin layer,
The method for producing a resin layer having a pattern, wherein the polymerizable unsaturated compound contains a (meth) acrylate compound having a urethane bond.   The method according to claim 1, further comprising irradiating the resin layer with light before the step of forming the pattern on the resin layer.   The method according to claim 1, wherein the resin composition further contains an inorganic filler.   The method of Claim 3 whose content of the said inorganic filler is 50-78 mass% with respect to the resin composition whole quantity.   The method according to claim 1, wherein the resin layer having the pattern is a permanent film.   The method according to claim 1, wherein the resin composition further contains a photopolymerization initiator.   The method as described in any one of Claims 1-6 whose thermal expansion coefficient after hardening of the said resin layer is 30 ppm / degrees C or less in 50-100 degreeC. Containing a polymerizable unsaturated compound including a (meth) acrylate compound having a urethane bond,
To form a resin layer in a method of manufacturing a resin layer comprising a step of pressing a mold having a concavo-convex pattern on a resin layer and forming a pattern inverted with respect to the concavo-convex pattern on the resin layer. A resin composition for imprints used in the above.   The resin composition for imprints according to claim 8, further comprising an inorganic filler.   The resin composition for imprints according to claim 9, wherein the content of the inorganic filler is 50 to 78 mass% with respect to the entire resin composition.   The resin composition for imprints according to any one of claims 8 to 10, further comprising a photopolymerization initiator.   The resin composition for imprints as described in any one of Claims 8-11 whose thermal expansion coefficient after hardening is 30 ppm / degrees C or less in 50-100 degreeC.   The resin film for imprints provided with the resin layer which consists of a resin composition for imprints as described in any one of Claims 8-12.   The resin layer which has a pattern which can be obtained by the method as described in any one of Claims 1-4, 6, and 7.   The resin layer having a pattern according to claim 14, which is a permanent film.   An electronic component comprising a resin layer having the pattern according to claim 14.

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