JP7540475B2 - Curable Composition - Google Patents

Description

This disclosure relates to a curable composition.

In order to increase the density and performance of semiconductor packages, a mounting form has been proposed in which chips with different performance are mixed in a single package. In this case, cost-effective high-density interconnect technology between chips is becoming important (see, for example, Patent Document 1).

As forms for mounting multiple chips at high density, packaging technology using organic substrates with high-density wiring, fan-out type packaging technology (FO-WLP: FanOut-WaferLevelPackage) with through mold vias (TMV: Through Mold Via), packaging technology using silicon or glass interposers, packaging technology using through silicon vias (TSV: Through Silicon Via), packaging technology using chips embedded in a substrate for inter-chip transmission, etc. have been proposed.

In particular, when mounting semiconductor chips on one another in a semiconductor wiring layer and FO-WLP, a fine wiring layer is required to electrically connect the semiconductor chips with high density (see, for example, Patent Document 2). Fine wiring with a line width and space width of, for example, 5 μm or less is arranged in the wiring layer. The wiring is formed, for example, by using the trench method. The trench method is a method in which a metal layer that will become the wiring is formed by plating or the like in a trench (groove) formed by a laser or the like on the surface of an insulating layer (interlayer insulating layer) formed between wiring layers.

The insulating properties of the wiring interlayer insulation layer must be maintained appropriately (excellent insulating reliability). For example, Patent Document 3 discloses a resin composition that contains a curable resin and a curing agent and is used to form a wiring interlayer insulation layer that contacts copper wiring, with the aim of providing a wiring interlayer insulation layer with good insulating reliability.

Special Publication No. 2012-529770 US Patent Application Publication No. 2011/0221071 International Publication No. 2018/056466

In addition to being excellent in insulation reliability, wiring interlayer insulation layers are required to exhibit low dielectric properties (low dielectric constant and dielectric tangent). Therefore, the present invention aims to provide a composition capable of forming wiring interlayer insulation layers that exhibit low dielectric properties and have excellent insulation reliability.

式（１）中、Ｒ^１１はアリル基を表し、ｍは０又は１を表す。 One aspect of the present invention is a composition containing a maleimide compound and a nadimide compound having a group represented by the following formula (1):

In formula (1), R ¹¹ represents an allyl group;

式（２）中、Ｒ^１１及びｍは、それぞれ独立に、前記式（１）中のＲ^１１及びｍとそれぞれ同義であり、Ｒ^１２は、２価の有機基を表す。 The nadimide compound may be a compound represented by the following formula (2).

In formula (2), R ¹¹ and m each independently have the same definition as R ¹¹ and m in formula (1), and R ¹² represents a divalent organic group.

式（３）中、Ｒ^１２は、前記式（２）中のＲ^１２と同義である。 The nadimide compound may be a compound represented by the following formula (3).

In formula (3), R ¹² has the same meaning as R ¹² in formula (2).

The divalent organic group may have an aromatic hydrocarbon group. The divalent organic group may be a divalent hydrocarbon group.

The above composition may be used to form an insulating layer between wiring layers in a semiconductor package.

The present invention makes it possible to form an insulating layer between wiring layers that exhibits low dielectric properties and has excellent insulation reliability.

1 is a schematic cross-sectional view showing an embodiment of a semiconductor package. 2 is a schematic cross-sectional view showing a wiring layer laminate included in the semiconductor package of FIG. 1 .

The composition according to one embodiment contains a maleimide compound and a nadimide compound. This composition is a curable composition that can be cured by heat and/or light. In this composition, the nadimide compound can function as a curing agent.

The composition contains one or more maleimide compounds having at least two maleimide groups represented by, for example, the following formula (I):

式中、Ｘは、２価の炭化水素基を含む２価の連結基である。 The maleimide compound is, for example, a compound represented by the following formula (II).

In the formula, X is a divalent linking group containing a divalent hydrocarbon group.

The divalent hydrocarbon group contained in the linking group represented by X may be either a saturated hydrocarbon group or an unsaturated hydrocarbon group. The divalent hydrocarbon group may be either a chain or a cyclic group, and the chain divalent hydrocarbon group may be either a straight chain or a branched chain. The cyclic unsaturated hydrocarbon group may be an aromatic group. The divalent hydrocarbon group may contain two or more of these groups.

From the viewpoint of improving the flexibility of the composition and the handleability (tackiness, cracking, powder fall, etc.) and strength of a film made from the composition, the divalent hydrocarbon group preferably contains a chain-like hydrocarbon group, and more preferably contains a chain-like alkylene group having a main chain with 6 or more carbon atoms.

A chain-like alkylene group having a main chain with 6 or more carbon atoms is represented by -(CR ^a R ^b ) _m - (where m is an integer of 6 or more, and R ^a and R ^b each independently represent a hydrogen atom or an alkyl group having less than m carbon atoms). The number of carbon atoms (m) in the main chain of the alkylene group is preferably 4 or more or 6 or more, and preferably 20 or less, 15 or less, or 10 or less.

The number of carbon atoms of the divalent hydrocarbon group is preferably 8 or more, 10 or more, or 15 or more, from the viewpoint of making it easy to make the molecular structure of the maleimide compound three-dimensional and increasing the free volume of the polymer to lower the density, i.e., to lower the dielectric constant, and is preferably 300 or less, 250 or less, 200 or less, 100 or less, 70 or less, or 50 or less. From the same viewpoint, the number of carbon atoms of the divalent hydrocarbon group may be preferably 8 to 300, 8 to 250, 8 to 200, or 8 to 100. The divalent hydrocarbon group is preferably an alkylene group having 8 to 300, 8 to 250, 8 to 200, or 8 to 100 carbon atoms, which may have a branch, more preferably an alkylene group having 10 to 70 carbon atoms, and even more preferably an alkylene group having 15 to 50 carbon atoms, which may have a branch.

式中、Ｒ^１及びＲ^２は、それぞれ独立にアルキレン基を表し、Ｒ^３及びＲ^４は、それぞれ独立にアルキル基を表す。 From the viewpoint of more effectively improving the high frequency characteristics and HAST (Highly Accelerated Temperature and Humidity Stress Test) resistance, the divalent hydrocarbon group may be a group represented by the following formula (III).

In the formula, ^R1 and ^R2 each independently represent an alkylene group, and ^R3 and ^R4 each independently represent an alkyl group.

From the viewpoint of further improving flexibility and ease of synthesis, the number of carbon atoms in the alkylene group represented by ^R1 or ^R2 is preferably 4 to 50, more preferably 5 to 25, even more preferably 6 to 10, and particularly preferably 7 to 10. The alkylene group represented by ^R1 and ^R2 is preferably a chain-like alkylene group having a main chain with 6 or more carbon atoms as described above.

The number of carbon atoms in the alkyl group represented by ^R3 or ^R4 is preferably 4 to 50, more preferably 5 to 25, even more preferably 6 to 10, and particularly preferably 7 to 10, from the viewpoint of further improving flexibility and ease of synthesis.

From the viewpoint of more effectively increasing the high frequency characteristics and elongation, the maleimide compound preferably has multiple divalent hydrocarbon groups. In this case, the multiple divalent hydrocarbon groups may be the same or different. The maleimide compound preferably has 2 to 40 divalent hydrocarbon groups, more preferably 2 to 20 divalent hydrocarbon groups, and even more preferably 2 to 10 divalent hydrocarbon groups.

The divalent hydrocarbon group may be, for example, an alkylene group such as a nonylene group, a decylene group, an undecylene group, a dodecylene group, a tetradecylene group, a hexadecylene group, an octadecylene group, a nonadecylene group, an icosilene group, an icosilene group, a docosilene group, a tricosilene group, a tetracosilene group, a pentacosilene group, a hexacosilene group, a heptacosilene group, an octacosilene group, a nonacosilene group, or a triacontylene group; an arylene group such as a benzylene group, a phenylene group, or a naphthylene group; an arylene alkylene group such as a phenylene methylene group, a phenylene ethylene group, a benzyl propylene group, a naphthylene methylene group, or a naphthylene ethylene group; or an arylene dialkylene group such as a phenylenedimethylene group or a phenylenediethylene group.

The linking group represented by X may consist only of the divalent hydrocarbon group described above, or may contain other organic groups in addition to the divalent hydrocarbon group described above. The other organic groups are, for example, divalent organic groups having at least two imide bonds.

式中、Ｒ^５は、４価の有機基を表す。 The divalent organic group having at least two imido bonds may be, for example, a group represented by the following formula (IV).

In the formula, ^R5 represents a tetravalent organic group.

The tetravalent organic group represented by ^R5 may be, for example, a hydrocarbon group from the viewpoint of handleability. The number of carbon atoms in the hydrocarbon group may be, for example, 1 to 100, 2 to 50, or 4 to 30.

The hydrocarbon group may be substituted, and may, for example, contain a substituted or unsubstituted siloxane group. Examples of the siloxane group include groups derived from dimethylsiloxane, methylphenylsiloxane, diphenylsiloxane, etc.

The substituent may be, for example, an alkyl group, an alkenyl group, an alkynyl group, a hydroxyl group, an alkoxy group, a mercapto group, a cycloalkyl group, a substituted cycloalkyl group, a heterocyclic group, a substituted heterocyclic group, an aryl group, a substituted aryl group, a heteroaryl group, a substituted heteroaryl group, an aryloxy group, a substituted aryloxy group, a halogen atom, a haloalkyl group, a cyano group, a nitro group, a nitroso group, an amino group, an amido group, -C(O)H, -C(O)-, -S-, -S(O) ₂ -, -OC(O)-O-, -C(O)-NR ^c , -NR ^c C(O)-N(R ^c ) ₂ , -OC(O)-N(R ^c ) ₂ , an acyl group, an oxyacyl group, a carboxyl group, a carbamate group, a sulfonyl group, a sulfonamide group, a sulfuryl group, etc. Here, R ^c represents a hydrogen atom or an alkyl group. One or more of these substituents may be selected depending on the purpose, application, etc.

The tetravalent organic group represented by ^R5 may be, for example, a tetravalent residue of an acid anhydride having two or more anhydride rings in one molecule, that is, a tetravalent group obtained by removing two acid anhydride groups (-CO(=O)OC(=O)-) from an acid anhydride. Examples of acid anhydrides include compounds described below.

From the viewpoint of excellent high frequency characteristics, the organic group represented by ^R5 is preferably a tetravalent aromatic group, more preferably a residue obtained by removing two acid anhydride groups from pyromellitic anhydride. The divalent organic group having at least two imide bonds is preferably a group represented by the following formula (V).

From the viewpoint of excellent dielectric properties, the divalent organic group having at least two imide bonds may be a group represented by the following formula (VI) or (VII).

The maleimide compound preferably has a plurality of divalent organic groups having at least two imide bonds, from the viewpoints of excellent high frequency characteristics and excellent compatibility with other resins when the composition further contains other resins (particularly high molecular weight thermoplastic elastomer resins). In this case, the plurality of divalent organic groups may be the same or different. The maleimide compound preferably has 2 to 40, more preferably 2 to 20, and even more preferably 2 to 10 divalent organic groups.

式中、Ｚ^１、Ｚ^２及びＺ^３は、それぞれ独立に上述した２価の炭化水素基を表し、Ｒ^５は式（ＩＶ）中のＲ^５と同義であり、ｎは１～１０の整数を表す。ｎが２以上である場合、複数のＺ^３は、互いに同一であっても異なっていてもよい。 More specifically, in one embodiment, the maleimide compound may be, for example, a compound represented by the following formula (VIII) or a compound represented by the following formula (IX).

In the formula, Z ¹ , Z ² and Z ³ each independently represent the above-mentioned divalent hydrocarbon group, R ⁵ has the same meaning as R ⁵ in formula (IV), and n represents an integer of 1 to 10. When n is 2 or more, multiple Z ^3s may be the same or different from each other.

The maleimide compound can be, for example, a commercially available product. Examples of commercially available products include maleimide compounds represented by formula (VIII), such as BMI-TMH, BMI-1000, BMI-1000H, BMI-1100, BMI-1100H, BMI-2000, BMI-2300, BMI-3000, BMI-3000H, BMI-4000, BMI-5100, BMI-7000, BMI-7000H (all trade names, manufactured by Daiwa Kasei Kogyo Co., Ltd.), BMI, BMI-70, and BMI-80 (all trade names, manufactured by K.I. Kasei Co., Ltd.). Commercially available products include, for example, SFR2300 (trade name, manufactured by Hitachi Chemical Co., Ltd.), BMI-1500, BMI-1700, BMI-3000, BMI-5000, and BMI-9000 (all trade names, manufactured by Designer Molecules Inc. (DMI)), which are maleimide compounds represented by formula (IX).

The weight average molecular weight Mw of the maleimide compound may be 1000 or more, 1500 or more, or 3000 or more, and may be 30000 or less, 20000 or less, or 15000 or less. From the viewpoints of solubility in solvents and compatibility with other components such as monomers and resins, the weight average molecular weight Mw of the maleimide compound is preferably 1000 to 30000, more preferably 1500 to 20000.

The weight average molecular weight Mw of the maleimide compound can be measured by gel permeation chromatography (GPC) under the following conditions.
Pump: L-6200 type [manufactured by Hitachi High-Technologies Corporation]
Detector: L-3300 RI [manufactured by Hitachi High-Technologies Corporation]
Column oven: L-655A-52 [manufactured by Hitachi High-Technologies Corporation]
Guard column and column: TSK Guardcolumn HHR-L + TSKgel G4000HHR + TSKgel G2000HHR [all manufactured by Tosoh Corporation, product names]
Column size: 6.0 x 40 mm (guard column), 7.8 x 300 mm (column)
Eluent: Tetrahydrofuran Sample concentration: 30 mg/5 mL
Injection volume: 20 μL
Measurement temperature: 40°C

The content of the maleimide compound may be, for example, 10% by mass or more, 40% by mass or more, or 80% by mass or more, and may be 99% by mass or less, 95% by mass or less, or 90% by mass or less, based on the total amount of solids in the composition.

式（１）中、Ｒ^１１はアリル基を表し、ｍは０又は１を表す。 The composition contains one or more nadimide compounds. The nadimide compounds are compounds having a group represented by the following formula (1):

In formula (1), R ¹¹ represents an allyl group;

式（２）中、Ｒ^１１及びｍは、それぞれ独立に、式（１）中のＲ^１１及びｍとそれぞれ同義であり、Ｒ^１２は、２価の有機基を表す。 The nadimide compound may have one group represented by formula (1), or may have two or more groups represented by formula (1), and preferably has two groups. The nadimide compound is preferably a compound represented by the following formula (2).

In formula (2), R ¹¹ and m each independently have the same definition as R ¹¹ and m in formula (1), and R ¹² represents a divalent organic group.

The divalent organic group represented by R ¹² may have an aromatic hydrocarbon group (aromatic ring). The aromatic hydrocarbon group (aromatic ring) may be a benzene residue, a toluene residue, a xylene residue, a naphthalene residue, or the like. The divalent organic group may have a linear, branched, or cyclic aliphatic hydrocarbon group. The aliphatic hydrocarbon group may be a linear, branched, or cyclic alkyl group. The divalent organic group may have both the aromatic hydrocarbon group (aromatic ring) and the aliphatic hydrocarbon group.

The divalent organic group represented by R ¹² may be a divalent hydrocarbon group containing only carbon atoms and hydrogen atoms, or a divalent organic group containing other atoms in addition to carbon atoms and hydrogen atoms, and is preferably a divalent hydrocarbon group.

式中、ｎは１～１０の整数である。 The divalent hydrocarbon group may be a divalent aliphatic hydrocarbon group, and may be a divalent aliphatic hydrocarbon group having the following structure:

In the formula, n is an integer from 1 to 10.

The divalent hydrocarbon group is preferably a divalent hydrocarbon group having an aromatic hydrocarbon group (aromatic ring), and more preferably a divalent hydrocarbon group having any of the following structures:

The divalent organic group containing other atoms may contain, in addition to carbon and hydrogen atoms, one or more of the following atoms: nitrogen atom, oxygen atom, sulfur atom, fluorine atom, etc. The divalent organic group containing other atoms is preferably a divalent hydrocarbon group having any of the following structures:

式（３）中、Ｒ^１２は、式（２）中のＲ^１２と同義である。 The nadimide compound is preferably a bisallylnadimide compound represented by the following formula (3) (a compound in which m in formula (2) is 1).

In formula (3), R ¹² has the same meaning as R ¹² in formula (2).

The nadimide compound is more preferably a bisallylnadimide compound in which R ¹² in formula (3) is a divalent hydrocarbon group having an aromatic hydrocarbon group (aromatic ring), and more preferably a bisallylnadimide compound represented by the following formula (3-1) or (3-2). From the viewpoint of being able to more suitably form a wiring interlayer insulating layer which has excellent UV curability and compatibility with maleimide compounds and exhibits low dielectric properties, a bisallylnadimide compound represented by the following formula (3-1) is more preferable.

The content of the nadiimide compound is preferably 1 part by mass or more, more preferably 10 parts by mass or more, and preferably 90 parts by mass or less, more preferably 50 parts by mass or less, from the viewpoint of sufficiently improving heat resistance, when the total of the maleimide compound and the nadiimide compound is 100 parts by mass.

The composition may further contain a compound having a (meth)acryloyl group (hereinafter also referred to as "(meth)acryloyl compound") from the viewpoint of improving the UV curability of the composition and also improving the compatibility between the maleimide compound and the nadimide compound. Note that a coupling agent having a (meth)acryloyl group, which will be described later, is not included in the (meth)acryloyl compound.

The (meth)acryloyl compound may be, for example, tricyclodecane dimethanol di(meth)acrylate, ethoxylated bisphenol A di(meth)acrylate, propoxylated ethoxylated bisphenol A (meth)acrylate, dipentaerythritol poly(meth)acrylate, ethoxylated isocyanuric acid tri(meth)acrylate, polyethylene glycol di(meth)acrylate, a silsesquioxane derivative having a (meth)acryloyl group, or the like.

From the viewpoint of excellent heat resistance, the (meth)acryloyl compound is preferably tricyclodecane dimethanol di(meth)acrylate, ethoxylated bisphenol A di(meth)acrylate, propoxylated ethoxylated bisphenol A (meth)acrylate, or a silsesquioxane derivative having a (meth)acryloyl group, and from the viewpoint of excellent compatibility with the maleimide compound, more preferably tricyclodecane dimethanol di(meth)acrylate.

The content of the (meth)acryloyl compound may be 0.1 parts by mass or more, 2 parts by mass or more, or 5 parts by mass or more, and may be 98 parts by mass or less, 50 parts by mass or less, or 40 parts by mass or less, when the total of the maleimide compound, the nadiimide compound, and the (meth)acryloyl compound is 100 parts by mass. From the viewpoint of being able to form a wiring interlayer insulating layer exhibiting further low dielectric properties, the content is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, even more preferably 10 parts by mass or less, and particularly preferably 5 parts by mass or less. In one embodiment, the composition does not contain a (meth)acryloyl compound, from the viewpoint of being able to more suitably form a wiring interlayer insulating layer exhibiting low dielectric properties.

The composition may further contain a photoradical polymerization initiator as a curing agent. The photoradical polymerization initiator may be, for example, an alkylphenone-based photoradical polymerization initiator, an acylphosphine oxide-based photoradical polymerization initiator, or the like.

Alkylphenone-based photoradical polymerization initiators can be purchased, for example, from BASF as Irgacure 651, Irgacure 184, DAROCURE 1173, Irgacure 2959, Irgacure 127, DAROCURE EMBF, Irgacure 907, Irgacure 369, Irgacure 379EG, etc. Acylphosphine oxide-based photoradical polymerization initiators can be purchased, for example, from BASF as Irgacure 819, LUCIRINTPO, etc.

The photoradical polymerization initiator may be other photoradical polymerization initiators available commercially as Irgacure 784, Irgacure OXE01, Irgacure OXE02, Irgacure 754, etc., manufactured by BASF.

As the photoradical polymerization initiator, from the viewpoint of high sensitivity, preferably Irgacure 907, Irgacure 369, Irgacure 379EG, Irgacure OXE01, and Irgacure OXE02 are used, and from the viewpoint of solubility in solvents, Irgacure 907, Irgacure 379EG, and Irgacure OXE02 are more preferably used. These photoradical polymerization initiators may be used alone or in combination of two or more types according to the purpose, application, etc.

The content of the photoradical polymerization initiator may be preferably 0.1 parts by mass or more and may be 10 parts by mass or less, from the viewpoint of sufficiently curing the curable composition when the total of the maleimide compound and the nadimide compound is 100 parts by mass, and more preferably 1 part by mass or more and may be 6 parts by mass or less, from the viewpoint of further reducing the likelihood of unreacted substances remaining.

The composition may further contain a coupling agent. The coupling agent may be, for example, a silane coupling agent. The silane coupling agent may have, for example, a vinyl group, an epoxy group, a styryl group, an acryloyl group, a methacryloyl group, an amino group, a ureido group, an isocyanate group, an isocyanurate group, a mercapto group, or the like.

Examples of silane coupling agents having a vinyl group include KBM-1003 and KBE-1003 (all trade names, manufactured by Shin-Etsu Chemical Co., Ltd.; the same applies below). Examples of silane coupling agents having an epoxy group include KBM-303, 402, 403, KBE-402, 403, X-12-981S, and X-12-984S. Examples of silane coupling agents having a styryl group include KBM-1403. Examples of silane coupling agents having a methacryloyl group include KBM-502, 503, KBE-502, 503, and the like. Examples of silane coupling agents having an acryloyl group include KBM-5103, X-12-1048, and X-12-1050. Examples of silane coupling agents having an amino group include KBM-602, 603, 903, 573, 575, KBE-903, 9103P, and X-12-972F. Examples of silane coupling agents having a ureido group include KBE-585. Examples of silane coupling agents having an isocyanate group include KBE-9007 and X-12-1159L. Examples of silane coupling agents having an isocyanurate group include KBM-9659. Examples of silane coupling agents having a mercapto group include KBM-802, 803, X-12-1154, and X-12-1156. These may be used alone or in combination of two or more types depending on the purpose and application.

The content of the silane coupling agent, when the total of the maleimide compound and the nadimide compound is taken as 100 parts by mass, may be preferably 0.01 parts by mass or more and may be 5 parts by mass or less from the viewpoint of improving adhesion to glass, silica, etc., and more preferably 0.1 parts by mass or more and may be 2 parts by mass from the viewpoint of further reducing the likelihood of unreacted substances remaining.

The composition may further contain a thermosetting resin. Examples of the thermosetting resin include epoxy resins, phenolic resins, cyanate resins, isocyanate resins, benzoxazine resins, oxetane resins, amino resins, unsaturated polyester resins, allyl resins, dicyclopentadiene resins, silicone resins, triazine resins, and melamine resins. However, the thermosetting resin does not include the maleimide compounds and nadimide compounds described above. The thermosetting resin may be used alone or in combination of two or more types. From the viewpoints of heat resistance and electrical insulation, the thermosetting resin is preferably an epoxy resin or a cyanate resin.

Epoxy resins include, for example, bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, phenol novolac type epoxy resins, cresol novolac type epoxy resins, bisphenol A novolac type epoxy resins, bisphenol F novolac type epoxy resins, stilbene type epoxy resins, triazine skeleton-containing epoxy resins, fluorene skeleton-containing epoxy resins, biphenyl type epoxy resins, xylylene type epoxy resins, biphenyl aralkyl type epoxy resins, naphthalene type epoxy resins, dicyclopentadiene type epoxy resins, alicyclic epoxy resins, polyfunctional phenols and diglycidyl ether compounds of polycyclic aromatics such as anthracene, and phosphorus-containing epoxy resins in which phosphorus compounds are introduced into these. From the viewpoints of heat resistance and flame retardancy, the epoxy resin is a biphenyl aralkyl type epoxy resin or a naphthalene type epoxy resin. These may be used alone or in a mixture of two or more.

Examples of cyanate resins include bisphenol-type cyanate resins such as novolac-type cyanate resins, bisphenol A-type cyanate resins, bisphenol E-type cyanate resins, and tetramethylbisphenol F-type cyanate resins, as well as prepolymers of these partially triazine-converted resins. These may be used alone or in combination of two or more types. From the viewpoints of heat resistance and flame retardancy, the cyanate resin is preferably a novolac-type cyanate resin.

The composition may further contain other curing agents as a curing agent in addition to the nadiimide compound and the photoradical polymerization initiator. Examples of other curing agents include aromatic amine compounds such as dicyandiamide, 4,4'-diaminodiphenylmethane, 4,4'-diamino-3,3'-diethyl-diphenylmethane, 4,4'-diaminodiphenylsulfone, phenylenediamine, and xylenediamine, aliphatic amine compounds such as hexamethylenediamine and 2,5-dimethylhexamethylenediamine, and guanamine compounds such as melamine and benzoguanamine. The other curing agent is preferably an aromatic amine compound from the viewpoint of obtaining good reactivity and heat resistance.

When the composition contains a cyanate resin, the composition may further contain, as a curing agent, a polyfunctional phenolic compound such as phenol novolac, cresol novolac, or aminotriazine novolac resin, or an acid anhydride such as phthalic anhydride, pyromellitic anhydride, maleic anhydride, or maleic anhydride copolymer. These may be used alone or in combination of two or more.

The composition may further contain a filler in order to impart low moisture absorption and low moisture permeability. The filler may be an inorganic filler made of an inorganic material, or an organic filler made of an organic material. These fillers are preferably insulating fillers.

Examples of inorganic fillers include alumina, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, aluminum oxide, aluminum nitride, crystalline silica, amorphous silica, boron nitride, titania, glass, iron oxide, ceramics, etc. Examples of organic fillers include carbon, rubber-based fillers, etc. Fillers can be used without particular restrictions, regardless of type, shape, etc.

The filler may be used according to the desired function. For example, inorganic fillers are added to the wiring interlayer insulating layer for the purpose of imparting thermal conductivity, low thermal expansion, low moisture absorption, etc. Organic fillers are added for the purpose of imparting toughness, etc. to the wiring interlayer insulating layer. The filler may contain at least one of inorganic fillers and organic fillers, and one type of filler may be used alone or in combination of two or more types. The filler is preferably an inorganic filler from the viewpoint of being able to impart thermal conductivity, low moisture absorption characteristics, insulation, etc. required for the wiring interlayer insulating layer, and is more preferably at least one of silica filler and alumina filler from the viewpoint of good dispersibility in resin varnish and the viewpoint of being able to impart high adhesive strength when heated.

The average particle diameter of the filler is, for example, 10 μm or less, and the maximum particle diameter of the filler is, for example, 30 μm or less. It is preferable that the average particle diameter of the filler is 5 μm or less, and the maximum particle diameter of the filler is 20 μm or less. By having an average particle diameter of 10 μm or less and a maximum particle diameter of 30 μm or less, the effect of improving the fracture toughness of the wiring interlayer insulation layer can be favorably exhibited, and the occurrence of a decrease in and variation in the adhesive strength of the wiring interlayer insulation layer can be suppressed, and the surface of the wiring interlayer insulation layer can be prevented from becoming rough and the adhesive strength from decreasing. There is no particular limit on the lower limit of the average particle diameter of the filler and the lower limit of the maximum particle diameter, but both may be 0.001 μm or more.

Methods for measuring the average particle size and maximum particle size of the filler include, for example, using a scanning electron microscope (SEM) to measure the particle size of about 20 fillers. Measurement methods using SEM include, for example, preparing a sample by heat-curing a composition containing the filler (preferably at 150-180°C for 1-10 hours), cutting the center of this sample, and observing the cross section with an SEM. In this case, it is preferable that the probability of the presence of fillers with a particle size of 30 μm or less in the cross section is 80% or more of the total fillers.

The content of the filler is appropriately determined according to the characteristics or functions to be imparted. For example, the content of the filler is preferably 1% by mass to 70% by mass, or 2% by mass to 60% by mass, and more preferably 5% by mass to 50% by mass, based on the mass of the composition. By increasing the content of the filler, the elastic modulus of the wiring interlayer insulating layer is increased. This effectively improves the dicing properties (cutting properties with a dicer blade), wire bonding properties (ultrasonic efficiency), and adhesive strength during heating. From the viewpoint of suppressing the deterioration of thermocompression bonding properties, the content of the filler is preferably equal to or less than the upper limit value described above. The optimal content of the filler may be determined to balance the desired characteristics. The mixing and kneading of the filler may be performed by appropriately combining a dispersing machine such as a normal mixer, a mortar mill, a three-roll mill, or a ball mill.

The composition may further contain an antioxidant from the viewpoints of storage stability, prevention of electromigration, and prevention of corrosion of the metal conductor circuit. There are no particular limitations on the antioxidant, and examples thereof include benzophenone-based, benzoate-based, hindered amine-based, benzotriazole-based, and phenol-based antioxidants. From the viewpoints of the effect of addition, heat resistance, cost, etc., the content of the antioxidant is preferably 0.01 parts by mass to 10 parts by mass per 100 parts by mass of the resin component.

The composition may further contain a catalyst to further accelerate the curing. Examples of catalysts include peroxides, imidazole compounds, organic phosphorus compounds, secondary amines, tertiary amines, and quaternary ammonium salts. These may be used alone or in combination of two or more. From the viewpoint of reactivity, the catalyst is preferably at least one selected from the group consisting of peroxides, imidazole compounds, and organic phosphorus compounds, and more preferably a peroxide, particularly from the viewpoint of contributing to the self-polymerization of the maleimide group and the reaction between the maleimide group and the acryloyl group.

The composition may further contain a flame retardant. Examples of the flame retardant include, but are not limited to, halogen-containing flame retardants such as bromine-based flame retardants and chlorine-based flame retardants, phosphorus-based flame retardants such as triphenyl phosphate, tricresyl phosphate, tris-dichloropropyl phosphate, phosphate ester compounds, and red phosphorus, nitrogen-based flame retardants such as guanidine sulfamate, melamine sulfate, melamine polyphosphate, and melamine cyanurate, phosphazene-based flame retardants such as cyclophosphazene and polyphosphazene, and inorganic flame retardants such as antimony trioxide. These flame retardants may be used alone or in combination of two or more.

The composition may further contain an ultraviolet absorber. The ultraviolet absorber is not particularly limited, but examples thereof include benzotriazole-based ultraviolet absorbers.

The composition may further contain a fluorescent whitening agent. Examples of the fluorescent whitening agent include, but are not limited to, stilbene derivatives.

From the viewpoint of ease of handling, the composition is preferably in the form of a film. The composition may also be in the form of a varnish (liquid) in which each component is dissolved or uniformly dispersed in a solvent.

There are no particular limitations on the means and conditions for preparing the varnish. For example, the main components in the prescribed amounts are thoroughly and uniformly stirred and mixed using a mixer or the like, then kneaded using a mixing roll, extruder, kneader, roll, extruder, or the like, and the resulting kneaded product is further cooled and pulverized. There are no particular limitations on the kneading method.

When the composition is a varnish, the solvent may be, for example, an organic solvent. The organic solvent is not particularly limited, but may be, for example, alcohols such as methanol, ethanol, butanol, butyl cellosolve, ethylene glycol monomethyl ether, and propylene glycol monomethyl ether; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and cyclopentanone; aromatic hydrocarbons such as toluene, xylene, mesitylene, and limonene; esters such as methoxyethyl acetate, ethoxyethyl acetate, butoxyethyl acetate, and ethyl acetate; and nitrogen-containing solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone. These may be used alone or in combination of two or more. In terms of solubility, the organic solvent is preferably toluene, xylene, cyclohexanone, cyclopentanone, limonene, or mesitylene, and more preferably cyclopentanone, limonene, or mesitylene in terms of low toxicity.

The organic solvent is preferably used in an amount such that the solid content of the composition in the varnish is 5 to 90% by mass, and more preferably in an amount such that the solid content is 10 to 60% by mass in order to maintain good handling and application/coating properties of the varnish.

The moisture absorption rate of the cured composition after being placed in an environment of 130°C and 85% relative humidity for 200 hours is preferably 1% by mass or less. The moisture absorption rate of the cured composition after being placed in an environment of 130°C and 85% relative humidity for 200 hours can be measured by the method described in the Examples.

The concentration of chloride ions in the cured product of the composition is preferably 5 ppm or less from the viewpoint of insulation reliability, and more preferably 3 ppm or less from the viewpoint of suppressing discoloration of copper wiring. The concentration of chloride ions can be measured by the following procedure. 1 g of the cured product sample and 10 g of ultrapure water as an extracting solution are placed in a heat-resistant container made of Teflon (registered trademark) and heated at 130°C for 5 hours. The extracting solution is then filtered and analyzed by ion chromatography. In the obtained chromatogram, the peak detected at elution times of 0 to 30 minutes is regarded as the total amount of eluted material, and the mass of chloride ions in the cured product sample is determined from the peak area of chloride ions at around 9.6 minutes. The ratio of the determined mass of chloride ions to the mass of the cured product sample is calculated as the concentration (ppm) of chloride ions in the cured product.
The conditions for the ion chromatography are as follows:
・Apparatus: Dionex ISC-2000
Detector: Electrical conductivity detector Column: AS20 (4 mmφ x 200 mm)
Column temperature: 30°C
・Flow rate: 1.0mL/min ・Injection volume: 25μL
Gradient settings: KOH concentration was set to 5 mM at 0 min, 5 mM at 5 min, 30 mM at 15 min, and 55 mM at 20 min.

In terms of suppressing crosstalk between wiring layers, the dielectric constant of the wiring interlayer insulating layer (cured product of the composition) at 10 GHz is preferably 3.6 or less, 3.2 or less, or 3.0 or less, and in terms of improving the reliability of electrical signals, it is more preferably 2.8 or less. The dielectric constant may be 1.0 or more. The dielectric loss tangent of the wiring interlayer insulating layer (cured product of the composition) at 10 GHz is preferably 0.012 or less, more preferably 0.008 or less, even more preferably 0.005 or less, and may be, for example, 0.0001 or more. The dielectric constant and dielectric loss tangent can be measured by the method described in the Examples.

The glass transition temperature of the cured composition is preferably 120°C or higher in terms of suppressing cracks during temperature cycling, and more preferably 140°C or higher in terms of reducing stress on the wiring. The glass transition temperature of the cured composition is preferably 240°C or lower in terms of enabling lamination at low temperatures, and more preferably 220°C or lower in terms of suppressing cure shrinkage. The glass transition temperature of the cured composition can be measured by the method described in the Examples.

The breaking elongation of the cured composition is preferably 5% or more from the viewpoint of reducing warping of the wiring interlayer insulating layer, more preferably 10% or more from the viewpoint of relieving stress on the copper wiring, and even more preferably 15% or more from the viewpoint of improving the temperature cycle reliability of the wiring layer laminate. The breaking elongation may be 200% or less. The breaking elongation can be measured by the method described in the examples.

From the viewpoint of heat resistance reliability, the 5% weight loss temperature of the cured composition is, for example, 300°C or higher. The 5% weight loss temperature of the cured composition can be measured using a simultaneous differential thermal and thermogravimetric analyzer (manufactured by Hitachi High-Tech Science Corporation, product name: TG/DTA6300) under the conditions of a heating rate of 10°C/min and a nitrogen flow of 400 mL/min, using a 300 μm thick cured sample obtained by curing the composition by heating at 180°C for 2 hours.

The storage modulus of the cured composition at 40°C may be 10 MPa to 5 GPa.

The composition described above is capable of forming an insulating layer between wiring layers that exhibits low dielectric properties and has excellent insulation reliability, and is therefore suitable for use as an insulating layer between wiring layers in semiconductor packages as described below.

Figure 1 is a schematic cross-sectional view showing one embodiment of a semiconductor package, and Figure 2 is a schematic cross-sectional view showing a wiring layer laminate included in the semiconductor package of Figure 1. As shown in Figure 1, the semiconductor package 100 includes a substrate 1, a wiring layer laminate 10 provided on the substrate 1, and semiconductor chips 2A and 2B mounted on the wiring layer laminate 10.

The substrate 1 is a sealed body formed by sealing the semiconductor chips 2C, 2D and the electrodes 5A, 5B with an insulating material 4. The semiconductor chips 2C, 2D in the substrate 1 can be connected to an external device via the electrodes exposed from the insulating material 4. The electrodes 5A, 5B function, for example, as conductive paths for electrically connecting the wiring layer stack 10 to an external device. The semiconductor chips 2A, 2B are fixed on the wiring layer stack 10 by corresponding underfills 3A, 3B, respectively, and are electrically connected to each other via surface wiring (not shown) provided in the wiring layer stack 10. Each of the semiconductor chips 2A to 2D is electrically connected to one of the wirings in the wiring layer stack 10.

Each of the semiconductor chips 2A to 2D is, for example, a graphic processing unit (GPU), a volatile memory such as a dynamic random access memory (DRAM) or a static random access memory (SRAM), a non-volatile memory such as a flash memory, an RF chip, a silicon photonics chip, a micro electro mechanical system (MEMS), a sensor chip, etc. The thickness of the semiconductor chips 2A and 2B may be, for example, 30 μm or more and 200 μm or less.

The underfills 3A and 3B are, for example, capillary underfill (CUF), molded underfill (MUF), paste underfill (NCP), film underfill (NCF), or photosensitive underfill. The underfills 3A and 3B are each composed mainly of a liquid curing resin (for example, epoxy resin). The insulating material 4 is, for example, a curing resin having insulating properties.

As shown in FIG. 2, the wiring layer laminate 10 includes a plurality of wiring layers 41, 42 each including organic insulating layers 21, 22, copper wirings 13, 14 embedded in the organic insulating layers 21, 22, and barrier metal films 15, 16 provided between the copper wirings 13, 14 and the organic insulating layers 21, 22, wiring interlayer insulating layers 17, 18 adjacent to the wiring layers 41, 42, and through wirings 19 penetrating the organic insulating layers 21, 22 and the wiring interlayer insulating layers 17, 18. The organic insulating layers 21, 22 and the wiring interlayer insulating layers 17, 18 are alternately laminated on the substrate 11. A portion of the surface of the copper wirings 13, 14 is exposed on one main surface side of the wiring layers 41, 42, and the wiring interlayer insulating layers 17, 18 are in contact with the exposed surfaces of the copper wirings 13, 14. The wiring interlayer insulating layers 17, 18 are hardened products of the above-mentioned composition. The organic insulating layers 21 and 22 can be layers formed from a photosensitive insulating resin. The copper wiring may be exposed on both main surfaces of the wiring layer, and the exposed surfaces of the copper wiring may be in contact with an insulating layer between wiring layers.

The substrate 11 is a support that supports the wiring layer laminate 10. The shape of the substrate 11 in a plan view is, for example, circular or rectangular. If the substrate 11 is circular, it has a diameter of, for example, 200 mm to 450 mm. If the substrate 11 is rectangular, one side of the substrate 11 is, for example, 300 mm to 700 mm.

The substrate 11 may be, for example, a silicon substrate, a glass substrate, or a peelable copper foil. When a silicon substrate or a glass substrate is used as the substrate 11, a temporary fixing layer (not shown) may be provided to temporarily fix the wiring layer laminate 10 and the substrate 11. In this case, the substrate 11 can be easily peeled off from the wiring layer laminate 10 by removing the temporary fixing layer. The peelable copper foil is a laminate in which a support, a peeling layer, and a copper foil are stacked in this order. In the peelable copper foil, the support corresponds to the substrate 11, and the copper foil can form part of the through wiring 19.

The organic insulating layer 21 (first organic insulating layer) includes a third organic insulating layer 23 located on the substrate 11 side and a fourth organic insulating layer 24 located on the second organic insulating layer 22 side. The first organic insulating layer 21 has a plurality of grooves 21a (first grooves) in which corresponding copper wiring 13 is arranged. The fourth organic insulating layer 24 has a plurality of openings corresponding to the grooves 21a. The surfaces of the third organic insulating layer 23 exposed by these openings form the bottom surfaces of the inner surfaces of the grooves 21a. The side surfaces of the grooves 21a are formed by the fourth organic insulating layer 24.

The third organic insulating layer 23 and the fourth organic insulating layer 24 may each have a thickness of, for example, 0.5 μm to 10 μm. The first organic insulating layer 21 may have a thickness of, for example, 1 μm to 20 μm.

The multiple grooves 21a are provided on the surface of the first organic insulating layer 21 opposite the substrate 11. In a cross section along a direction perpendicular to the extension direction of the grooves 21a, each of the grooves 21a has a substantially rectangular shape. The inner surface of the grooves 21a has a side surface and a bottom surface. The multiple grooves 21a have a predetermined line width L and space width S. The line width L and space width S may each be independently 0.5 μm to 10 μm, for example. The line width L corresponds to the width of the grooves 21a in a direction perpendicular to the extension direction of the grooves 21a in a plan view. The space width S corresponds to the distance between adjacent grooves 21a. The depth of the grooves 21a corresponds to, for example, the thickness of the fourth organic insulating layer 24.

The organic insulating layer 22 (second organic insulating layer) is laminated on the first organic insulating layer 21 with the wiring interlayer insulating layer 17 (first wiring interlayer insulating layer) sandwiched therebetween. The second organic insulating layer 22 has a plurality of grooves 22a (second grooves) in which corresponding copper wiring 14 is arranged.

The thickness of the second organic insulating layer 22 may be, for example, 1 μm to 10 μm. A portion of the second organic insulating layer 22 has a plurality of openings corresponding to the grooves 22a. The surface of the first wiring interlayer insulating layer 17 exposed by these openings constitutes the bottom surface of the inner surface of the grooves 22a. Each side surface of the grooves 22a is constituted by the second organic insulating layer 22. The line width and space width of the plurality of grooves 22a are the same as the line width L and space width S of the grooves 21a.

The copper wiring 13 is provided in the corresponding groove portion 21a as described above, and functions as a conductive path inside the wiring layer laminate 10. The width of the copper wiring 13 is approximately equal to the line width L of the groove portion 21a, and the distance between adjacent copper wirings 13 is approximately equal to the space width S of the groove portion 21a. The copper wiring 14 is provided in the corresponding groove portion 22a as described above, and functions as a conductive path inside the wiring layer laminate 10. Therefore, the width of the copper wiring 13 is approximately equal to the line width of the groove portion 22a, and the distance between adjacent copper wirings 14 is approximately equal to the space width of the groove portion 22a. The copper wiring 14 contains the same metal material as the copper wiring 13.

The barrier metal film 15 (first barrier metal film) is a metal film provided to separate the copper wiring 13 from the first organic insulating layer 21 (i.e., the inner surface of the groove portion 21a). The first barrier metal film 15 is a film for preventing the diffusion of copper from the copper wiring 13 into the first organic insulating layer 21, and is formed along the inner surface of the groove portion 21a. For this reason, the first barrier metal film 15 contains a metal material that is difficult to diffuse into the organic insulating layer (e.g., titanium, chromium, tungsten, palladium, nickel, gold, tantalum, or an alloy containing these).

The thickness of the first barrier metal film 15 is less than half the width of the groove portion 21a and less than the depth of the groove portion 21a. From the viewpoint of preventing electrical conduction between the copper wirings 13 and suppressing an increase in the resistance of the copper wiring 13, the thickness of the first barrier metal film 15 may be, for example, 0.001 μm to 0.5 μm.

The second barrier metal film 16 is a metal film provided to separate the copper wiring 14 from the second organic insulating layer 22 (i.e., the inner surface of the groove 22a). The second barrier metal film 16 is a film for preventing the diffusion of copper from the copper wiring 14 into the second organic insulating layer 22, and is formed along the inner surface of the groove 22a. For this reason, the second barrier metal film 16, like the first barrier metal film 15, contains a metal material that is difficult to diffuse into the organic insulating layer. The thickness of the second barrier metal film 16, like the first barrier metal film 15, is less than half the width of the groove 22a and less than the depth of the groove 22a, and may be, for example, 0.001 μm to 0.5 μm.

The first wiring interlayer insulating layer 17 is an insulating film for preventing diffusion of copper from the copper wiring 13 to the first organic insulating layer 21 and the second organic insulating layer 22. The first wiring interlayer insulating layer 17 is provided between the wiring layer 41 (first wiring layer) and the wiring layer 42 (second wiring layer) so as to separate the copper wiring 13 from the second organic insulating layer 22. The first wiring interlayer insulating layer 17 is in contact with the surface of the copper wiring 13 exposed on the main surface of the first wiring layer 41 opposite the substrate 11. From the viewpoint of being able to thin the wiring layer laminate 10, the thickness of the first wiring interlayer insulating layer 17 may be, for example, 50 μm or less.

The second wiring interlayer insulating layer 18 is an insulating film for preventing diffusion of copper from the copper wiring 14 to the second organic insulating layer 22. The second wiring interlayer insulating layer 18 is provided on the second wiring layer 42 while being in contact with the surface of the copper wiring 14 exposed on the main surface of the second wiring layer 42 opposite the substrate 11. The second wiring interlayer insulating layer 18 contains the same material as the first wiring interlayer insulating layer 17, and has the same characteristics as the first wiring interlayer insulating layer 17.

The through wiring 19 is a wiring embedded in a via 31 that penetrates the wiring layers 41, 42 and the wiring interlayer insulating layers 17, 18, and functions as a connection terminal to an external device.

The copper wiring in the semiconductor package may be formed by the trench method as described above, or in another embodiment, by SAP (Semi Additive Process). In either case, the composition described above is suitable for use in forming an insulating layer between wiring layers.

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

（Ａ－２）：下記式で表されるマレイミド化合物の混合物（大和化成工業株式会社製、商品名：ＢＭＩ－ＴＭＨ）

（ａ－１）：アクリル系エラストマ（日立化成株式会社製、商品名：ＫＨ－ＣＴ－８６５） In the examples and comparative examples, the following components were used.
(A-1): Maleimide compound represented by the following formula (mixture of n=1 to 10, weight average molecular weight: about 15,000 to 20,000, manufactured by Hitachi Chemical Co., Ltd., product name: SFR2300)

(A-2): A mixture of maleimide compounds represented by the following formula (manufactured by Daiwa Chemical Industry Co., Ltd., product name: BMI-TMH)

(a-1): Acrylic elastomer (manufactured by Hitachi Chemical Co., Ltd., product name: KH-CT-865)

（Ｂ－２）：下記式（３－２）で表されるナジイミド化合物（丸善石油化学株式会社製、商品名：ＢＡＮＩ－Ｍ）

（ｂ－１）液状エポキシ樹脂(ｊＥＲ８１１、三菱ケミカル株式会社製)とした場合の比較例を追記いたしました。 (B-1): A nadimide compound represented by the following formula (3-1) (manufactured by Maruzen Petrochemical Co., Ltd., product name: BANI-X)

(B-2): A nadimide compound represented by the following formula (3-2) (manufactured by Maruzen Petrochemical Co., Ltd., product name: BANI-M)

(b-1) A comparative example using liquid epoxy resin (jER811, manufactured by Mitsubishi Chemical Corporation) has been added.

(C): Tricyclodecane dimethanol diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., product name: A-DCP)
(D): Photoradical polymerization initiator (manufactured by BASF, product name: IrgacureOXE02)
(E): Silane coupling agent having an epoxy group (manufactured by Shin-Etsu Chemical Co., Ltd., product name: X-12-984S)

<Evaluation of dielectric properties>
The above components were mixed in the compounding ratios shown in Tables 1 to 3 to prepare a varnish. The prepared varnish was spin-coated on peelable copper foil under the following conditions, and then dried, exposed, and baked after exposure to form a resin film. This was repeated multiple times to obtain a resin film having a thickness of about 30 to 100 μm. It was then cured at 220° C. for 2 hours. The copper foil was then peeled off and dissolved and removed with ammonium persulfate to obtain an evaluation sample.
The conditions for spin coating, drying, exposure and post-exposure baking were as follows.
Spin coating conditions: Step 1: 1000 rpm/5 seconds, Step 2: 2000 rpm/30 seconds, SLOPE: 5 seconds. Drying conditions: 90° C., 3 minutes. Exposure conditions: Exposure amount: 1000 mJ/cm ²
Broadband exposure and post-exposure bake (PEB)
100°C, 1 min

The dielectric properties (dielectric constant Dk and dielectric loss tangent Df) were measured by the SPDR method using evaluation samples cut to a specified size. An SPDR dielectric resonator manufactured by Agilent Technologies was used for the SPDR, an Agilent Technologies vector network analyzer E8364B was used for the measurement, and the measurement program was CPMA-V2. The conditions were a frequency of 10 GHz and a measurement temperature of 25°C.

<Evaluation of insulation reliability (b-HAST resistance)>
The above varnish was applied by spin coating onto the comb-like wiring prepared using SAP, followed by drying, exposure and PEB to prepare an evaluation sample. The conditions for spin coating, drying, exposure and post-exposure baking were the same as those for the evaluation sample for dielectric properties. The prepared comb-like wiring was left to stand with a voltage of 3.3 V applied under conditions of 85% humidity and 130° C. The resistance value between the anode and cathode was measured at scheduled time intervals, and samples that had a resistance value of 1×10 ⁶ Ω or more for 300 hours or more were rated as “A” (with insulation reliability (b-HAST resistance)), and samples that did not had such a resistance value were rated as “B” (without insulation reliability (b-HAST resistance)).

<Measurement of Glass Transition Temperature>
An evaluation sample was prepared in the same manner as the evaluation sample for dielectric properties, and cut into a size of 8 mm x 3 cm. This sample was measured by a tensile method using a DMA (dynamic viscoelasticity measurement) device (manufactured by UBM Corporation, product name: Rheogel-E4000) under conditions of a chuck distance of 20 mm, a frequency of 10 Hz, a heating rate of 10°C/min, and a temperature range of -30 to 300°C. The temperature at which tan δ was maximum was recorded as the glass transition temperature (°C).

<Measurement of linear expansion coefficient>
Evaluation samples prepared in the same manner as the samples for evaluating dielectric properties were cut into pieces measuring 4 mm x 3 cm, and the linear expansion coefficient α1 (10 -6 /K) at 50°C to 70°C and the linear expansion coefficient α2 ( ^{10 -6} /K) at 200°C to 220°C were measured by a tensile method using a TMA (thermal mechanical analysis) device (Seiko Instruments Inc., product name: TMA/SS6000) under a load of 10 mN and the following temperature conditions:
Temperature conditions: 30°C → 200°C (heating rate: 10°C/min)
200℃→30℃ (Cooling rate 20℃/min)
30°C → 260°C (heating rate 5°C/min)
260℃→30℃ (temperature fall rate 20℃/min)

<Sputter resistance>
The above varnish was applied by spin coating onto a silicon wafer (6 inch diameter, 400 μm thick), and then heated and dried at 90°C for 3 minutes to form a resin film on the silicon wafer. It was exposed to light at 1000 mJ/ ^cm2 using a high-precision parallel exposure machine (manufactured by Oak Manufacturing Co., Ltd., product name: EXM-1172-B-∞). After additional heating at 100°C for 1 minute, the wafer was further heated at 220°C for 2 hours to obtain a sample.
A 50 nm titanium film was formed on the resin film of the obtained sample by sputtering, and then a 150 nm copper film was formed by sputtering. After cooling, the sample was taken out and the presence or absence of cracks or wrinkles in the sputtered film was observed under a microscope. The sputtered film was evaluated as "A" (sputter resistant) when no cracks or wrinkles were observed, and "B" (no sputter resistance) when cracks or wrinkles were observed.

<Measurement of moisture absorption rate>
The above varnish was applied to a wafer (6 inch diameter, 400 μm thick) using a spin coater, and dried at 90 ° C / 3 minutes to form a resin layer. After curing by exposure at 1000 mJ / cm ² , a sample was prepared by heating at 220 ° C / 2 hours. This sample was left for 200 hours in a thermo-hygrostat (manufactured by Espec Corporation, product name: EHS-221MD) set at a relative humidity of 85% and 130 ° C. Then, after lowering the temperature in the thermo-hygrostat to 50 ° C, the sample was taken out and a part of the resin was scraped off from the silicon wafer. A part of the scraped off resin was measured using a differential thermal thermogravimetry simultaneous measurement device (manufactured by Hitachi High-Tech Science Corporation, product name: TG / DTA6300) under the conditions of a heating rate of 10 ° C / min, a nitrogen flow of 400 mL / min, and a temperature range of 25 ° C to 150 ° C. On the other hand, a sample prepared in the same manner was dried at 130° C. for 2 hours and subjected to TG-DTA measurement in the same manner. The difference between the weight loss rates at 150° C. was calculated as the moisture absorption rate.

<Measurement of elongation rate>
The varnish was spin-coated on the peelable core and dried. Next, exposure was performed through a mask with a length of 30 mm and a width of 5 mm. The obtained sample was developed and then cured at 220°C for 2 hours. Thereafter, the copper foil was etched in the same manner as above to obtain a resin film. The resulting sample was measured for breaking elongation at a feed rate of 5 mm/min using a small tabletop tester (manufactured by Shimadzu Corporation, product name: EZ-S). The resin film produced by this method had smooth edges, so a higher elongation was obtained compared to samples cut out using a blade such as a cutter.

<Evaluation of fine wiring formability>
A varnish was applied by spin coating onto a silicon wafer (6 inch diameter, 400 μm thick), and the wafer was dried at 90° C. for 3 minutes to form a resin film on the silicon wafer. At that time, the spin coating conditions were adjusted so that the resin film thickness after drying was 5 μm. Next, a negative pattern mask with Line/Space (L/S (μm/μm)) of 200/200, 100/100, 80/80, 60/60, 50/50, 40/40, 30/30, 20/20, 10/10, 7/7, 5/5, 4/4, and 3/3 and via diameters of 50, 40, 30, 20, 10, 7, 5, 4, and 3 μm was placed on the wafer, and the wafer was exposed at 1000 mJ/cm ² using a high-precision parallel exposure machine (manufactured by Oak Manufacturing, product name: EXM-1172-B-∞). Further, additional heating was performed under the condition of 100°C/1 minute to obtain a sample. The obtained sample was immersed in cyclopentanone at room temperature (25°C) for 60 seconds while being shaken, then rinsed with cyclopentanone, and then immersed in isopropyl alcohol at room temperature (25°C) for 5 seconds. Thereafter, the isopropyl alcohol was volatilized by blowing compressed air on it, for example.
The fine wiring formability was confirmed by checking with a metal microscope for peeling of the resin film from the wafer, cracks in the resin film, roughness at the pattern edge, and the presence or absence of residue at the bottom of the pattern after developing the resin. The smallest L/S and via diameter at which these defects could not be confirmed were defined as the fine processability.

The evaluation results for each of the characteristics described above are shown in Tables 1 to 3.

1...substrate, 2A-2D...semiconductor chips, 3A, 3B...underfill, 4...insulating material, 10...wiring layer laminate, 11...substrate, 13...copper wiring, 14...copper wiring, 15, 16...barrier metal film, 17, 18...wiring interlayer insulating layer, 21...organic insulating layer, 21a...groove, 22...organic insulating layer, 22a...groove, 100...semiconductor package, L...line width, S...space width.

Claims (7)

A curable composition comprising a maleimide compound represented by the following formula (VIII) or the following formula (IX), a nadimide compound having a group represented by the following formula (2), and a photoradical polymerization initiator,
The content of the maleimide compound is 10 mass% or more based on the total amount of solids in the curable composition,
The content of the nadimide compound is 1 part by mass or more and 90 parts by mass or less when the total amount of the maleimide compound and the nadimide compound is 100 parts by mass.
Curable compositions.

[In formula (VIII), ^Z1 represents a chain divalent hydrocarbon group (excluding aliphatic hydrocarbon groups having 26 to 54 carbon atoms). In formula (IX), ^Z2 and ^Z3 each independently represent a divalent hydrocarbon group, ^R5 represents a tetravalent aromatic hydrocarbon group, and n represents an integer of 1 to 10. In formula (2), ^R11 represents an allyl group, m represents 0 or 1, and ^R12 represents a divalent hydrocarbon group having an aromatic hydrocarbon group.] The curable composition according to claim 1, wherein in formula (VIII), Z ¹ represents a linear and branched divalent hydrocarbon group (excluding aliphatic hydrocarbon groups having 26 to 54 carbon atoms). The curable composition according to claim 1 or 2, wherein the content of the maleimide compound is (60/103.3) x 100 mass% or more based on the total amount of solids in the curable composition. The curable composition according to any one of claims 1 to 3, further comprising a compound having a (meth)acryloyl group. The curable composition according to any one of claims 1 to 4, further comprising a coupling agent. The curable composition according to any one of claims 1 to 5, wherein the content of the nadiimide compound is 37.5 parts by mass or less when the total of the maleimide compound and the nadiimide compound is 100 parts by mass. The curable composition according to any one of claims 1 to 6, which is used for forming an insulating layer between wiring layers of a semiconductor package.

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