JP7666026B2 - Resin composition, cured film, method for producing a pattern of the cured film, and electronic component - Google Patents

Description

The present invention relates to a resin composition. More specifically, the present invention relates to a photosensitive resin composition that is suitable for use as a surface protective film or interlayer insulating film for electronic components such as semiconductor elements, or as an insulating layer for organic electroluminescent elements.

Conventionally, polyimide resins and polybenzoxazole resins, which have excellent heat resistance and mechanical properties, have been widely used for surface protection films and interlayer insulating films of semiconductor elements of electronic components. Usually, polyimide resins and polybenzoxazole resins are obtained by thermally dehydrating and cyclizing the coating film of their precursors to obtain thin films with excellent heat resistance and mechanical properties. In this case, high-temperature baking at about 350°C is usually required. However, for example, MRAM (Magnetoresistive Random Access Memory), which is promising as a next-generation memory, and sealing resins are weak at high temperatures. Therefore, in order to use it for the surface protection film of such elements and the interlayer insulating film of fan-out wafer-level packages that form a rewiring structure on the sealing resin, there is a demand for polyimide resins or polybenzoxazole resins that can be hardened by baking at a low temperature of about 250°C or less and can obtain high film properties such as heat resistance and mechanical properties that are comparable to conventional materials baked at a high temperature of about 350°C. In addition, in recent years, semiconductor packages have become finer and finer in wiring in response to demands for higher integration, miniaturization, and higher speeds. Therefore, there is a demand for insulating materials with low water absorption to resist cracking due to the stress that accompanies multi-layering, as well as to suppress changes in parasitic components (resistance, capacitance, etc.) and defects during the reflow process.

Surface protective films and interlayer insulating films of semiconductor elements of electronic components require the formation of through holes, etc. One of the methods for forming such films is etching using a positive photoresist. However, this method requires the steps of applying and peeling off the photoresist, which is problematic in that it is cumbersome. Therefore, heat-resistant materials that have been given photosensitivity have been studied for the purpose of streamlining the work process. When using a resin cured film formed from a photosensitive resin composition that has been given photosensitivity, additives such as the photosensitizer, sensitizer, acid generator, and dissolution regulator that make up the composition remain in the cured film even after heat curing, so the adhesive strength with the base metal is lower, the curing temperature is higher, and the dielectric constant is also higher than those that do not contain additives. In response to these issues, technologies have been disclosed, such as a photosensitive resin composition that suppresses copper corrosion by adding a copper discoloration inhibitor to the photosensitive resin (see Patent Document 1), and a photosensitive resin composition that combines low-temperature curing and photosensitivity due to a photobase generator (see Patent Document 2).

In addition to photosensitive resin compositions, there have also been reports of studies on processing polyimide with a laser without using a photosensitizer (see Patent Document 3).

JP 2011-169980 A JP 2011-213783 A JP 2001-213962 A

However, the photosensitive resin composition described in Patent Document 1, in which a copper discoloration inhibitor is added to the photosensitive resin, does not have sufficient adhesion strength to copper, and the photosensitive resin composition described in Patent Document 2, in which a photobase generator is added, has good physical properties but has problems such as poor storage stability. Furthermore, the polyimide for laser processing described in Patent Document 3 has low elongation and strength, and is insufficiently imidized at low temperatures. In addition, all of these have the high water absorbency characteristic of polyimides.

In order to solve the above problems, the present invention relates to the following.
The present invention comprises a polyimide precursor (A) having an acid anhydride residue represented by formula (1) and an alicyclic diamine residue, and a solvent (B),
The alicyclic diamine residue has one or more structures selected from the group consisting of formula (2), formula (3), and formula (4).

In formula (1), ^X1 and ^X2 each represent an oxygen atom, a sulfur atom, or an --NH-- group, and n represents an integer of 4 to 20.

In formula (2), the * symbol indicates the bond.

In formula (3), ^R1 and ^R2 each independently represent a hydrogen atom, a methyl group, or a trifluoromethyl group, and m represents an integer ranging from 1 to 10. The symbol * represents a bond.

In formula (4), ^R3 and ^R4 each independently represent a hydrogen atom, a methyl group, or a trifluoromethyl group, and the asterisk (*) represents a bond.

The resin composition of the present invention has excellent room temperature storage stability and low temperature curing properties. In addition, the cured film obtained by curing the composition has high elongation, high strength, and low water absorption.

1 is an enlarged cross-sectional view of a pad portion of a semiconductor device having bumps; 1A to 1C are diagrams illustrating a detailed method for manufacturing a semiconductor device having bumps. 1 is an enlarged cross-sectional view of a pad portion of a semiconductor device according to an embodiment of the present invention; 1 is a cross-sectional view of a coil component of an inductor device showing an embodiment of the present invention. 1 is a schematic diagram of a coplanar feed type microstrip antenna, which is a type of planar antenna. 1 is a schematic diagram showing a cross section of a semiconductor package including an IC chip (semiconductor element), rewiring, a sealing resin, and an antenna element.

The present invention relates to a polyimide precursor (A) having an acid anhydride residue represented by formula (1) and an alicyclic diamine residue, and a solvent (B),
The alicyclic diamine residue is a resin composition having one or more structures selected from the group consisting of formula (2), formula (3), and formula (4).

In the formula, ^X1 and ^X2 each represent an oxygen atom, a sulfur atom, or an --NH-- group, and n represents an integer of 4 to 20.

In formula (2), the * symbol indicates the bond.

In formula (3), R ¹ and R ² each independently represent a hydrogen atom, a methyl group, or a trifluoromethyl group, m represents an integer in the range of 1 to 10, and the * symbol represents a bond.

In formula (4), ^R3 and ^R4 each independently represent a hydrogen atom, a methyl group or a trifluoromethyl group, and the * symbol represents a bond.
Each component will be described below.

The polyimide precursor (A) (hereinafter, sometimes abbreviated as component (A)) contains a residue of an acid anhydride represented by formula (1).
Since the component (A) contains a residue of an acid anhydride represented by formula (1), the resin composition can be imidized at a low temperature of 250° C. or less without using an imidization accelerator such as a base generator when curing the resin composition. The imidization makes the resin insoluble in various solvents and cures the resin composition. In addition, the cured film obtained by curing the resin composition has high elongation and strength, and is excellent in processability with a UV laser.

In formula (1), X ¹ and X ² represent either an oxygen atom, a sulfur atom, or an -NH- group. Of these, from the viewpoint of the solvent solubility of the (A) component, it is preferable that both X ¹ and X ² are oxygen atoms. In formula (1), n represents an integer of 4 to 20. Of these, n is preferably 8 to 16 from the viewpoint of the balance of low-temperature curing property, moisture absorption, and heat resistance. When n is less than 4, it is difficult to obtain the effect of promoting imidization at low temperatures, and when n is 21 or more, there is a concern about a decrease in the glass transition point. Here, when "-" is written in the present invention, it means that the upper and lower limit numbers are included unless otherwise specified.

It is preferable that the (A) polyimide precursor contains 30 mol % or more and 100 mol % or less of the acid anhydride residue represented by the formula (1) relative to 100 mol % of all carboxylic acid residues in the (A) polyimide precursor. By setting the content within the above range, the curing temperature can be lowered. There is no particular upper limit, but by keeping the content at 70 mol % or less, different properties can be imparted depending on the other monomers, and at 50 mol % or less, the balance with other properties is even better, which is more preferable.

Examples of the acid anhydride represented by the formula (1) include tetramethylene bistrimellitate dianhydride, pentamethylene bistrimellitate dianhydride, hexamethylene bistrimellitate dianhydride, heptamethylene bistrimellitate dianhydride, octamethylene bistrimellitate dianhydride, nonamethylene bistrimellitate dianhydride, decamethylene bistrimellitate dianhydride, dodecamethylene bistrimellitate dianhydride, tetradecamethylene bistrimellitate dianhydride, hexadecane Ester compounds such as camethylene bistrimellitate dianhydride and octadecamethylene bistrimellitate dianhydride, as well as tetraethylene bistrimellitate amide dianhydride, pentamethylene bistrimellitate amide dianhydride, hexamethylene bistrimellitate amide dianhydride, heptamethylene bistrimellitate amide dianhydride, octamethylene bistrimellitate amide dianhydride, nonamethylene bistrimellitate amide dianhydride, decamethylene bistrimellitate amide dianhydride, Examples of the amide compounds include water, dodecamethylene bistrimellitic acid amide dianhydride, tetradecamethylene bistrimellitic acid amide dianhydride, hexadecamethylene bistrimellitic acid amide dianhydride, and octadecamethylene bistrimellitic acid amide dianhydride, as well as thioester compounds such as tetraethylene bistrimellitic acid thioester dianhydride, pentamethylene bistrimellitic acid thioester dianhydride, hexamethylene bistrimellitic acid thioester dianhydride, heptamethylene bistrimellitic acid thioester dianhydride, octamethylene bistrimellitic acid thioester dianhydride, nonamethylene bistrimellitic acid thioester dianhydride, decamethylene bistrimellitic acid thioester dianhydride, dodecamethylene bistrimellitic acid thioester dianhydride, tetradecamethylene bistrimellitic acid thioester dianhydride, hexadecamethylene bistrimellitic acid thioester dianhydride, and octadecamethylene bistrimellitic acid thioester dianhydride. From the viewpoint of a balance between low-temperature curing property, moisture absorption, solvent solubility, and heat resistance, examples of suitable acid anhydrides include octamethylene bistrimellitate dianhydride, nonamethylene bistrimellitate dianhydride, decamethylene bistrimellitate dianhydride, and dodecamethylene bistrimellitate dianhydride. The above acid anhydrides can be used alone or in combination of two or more. These tetracarboxylic acid dianhydrides can be synthesized from trimellitic anhydride monochloride and the corresponding diol.

Component (A) further contains an alicyclic diamine residue. The alicyclic diamine residue has one or more structures selected from the group consisting of formula (2), formula (3), and formula (4). By having such a residue, water absorption is suppressed, and the moisture absorption rate under constant temperature and humidity conditions (e.g., 23°C/45% RH) can be suppressed. In addition, it plays a role in supporting the imidization of the acid anhydride residue represented by formula (1) at low temperatures.

In formula (2), the symbol * indicates a bond.
Examples of alicyclic diamines having a structure represented by formula (2) include trans-1,4-cyclohexanediamine, trans-1,3-cyclohexanediamine, trans-1,2-cyclohexanediamine, cis-1,4-cyclohexanediamine, cis-1,3-cyclohexanediamine, cis-1,2-cyclohexanediamine, 1,2-bis(aminomethyl)cyclohexane, 1,3-bis(aminomethyl)cyclohexane, and 1,4-bis(aminomethyl)cyclohexane. Among these, trans-1,4-cyclohexanediamine is preferred because it has a small thermal expansion.

In formula (3), ^R1 and ^R2 each independently represent a hydrogen atom, a methyl group, or a trifluoromethyl group, and m represents an integer ranging from 1 to 10. The symbol * represents a bond.
Examples of the alicyclic diamine having the structure represented by formula (3) include 4,4'-methylenebis(cyclohexylamine), 4,4'-methylenebis(2-methylcyclohexylamine), 4,4'-isopropylidenebis(cyclohexylamine), 4,4'-isopropylidenebis(2-methylcyclohexylamine), 4,4'-hexafluoroisopropylidenebis(cyclohexylamine), and 4,4'-hexafluoroisopropylidenebis(2-methylcyclohexylamine).

In formula (4), ^R3 and ^R4 each independently represent a hydrogen atom, a methyl group, or a trifluoromethyl group, and the asterisk (*) represents a bond.
Examples of the alicyclic diamine having the structure represented by formula (4) include 4,4'-bicyclohexyldiamine, 2,2'-methyl-4,4'-aminobicyclohexane, and 2,2'-trifluoromethyl-4,4'-aminobicyclohexane.

In the present invention, it is preferable that component (A) is a resin structure having a structure represented by the following formula (5).

In formula (5), each of the ^R5 's independently represents a tetravalent to hexavalent organic group having 4 to 40 carbon atoms. Each of the ^R6 's independently represents a divalent organic group having 2 to 40 carbon atoms, and ^R7 represents a hydrogen atom or an organic group having 1 to 20 carbon atoms. 1 is an integer of 2 to 4.

The component (A) may contain an acid anhydride residue other than the acid anhydride residue represented by the formula (1).
Among these, from the viewpoint of processability with a UV laser, it is preferable that the compound contains an aromatic acid dianhydride residue, and it is more preferable that the compound contains a biphenyltetracarboxylic acid dianhydride residue or a derivative residue thereof.

Specific examples include pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,3,3',4'-biphenyltetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 2,2',3,3'-benzophenonetetracarboxylic dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 2,2-bis(2,3-dicarboxyphenyl)propane dianhydride, 1,1-bis(3,4-dicarboxyphenyl)ethane dianhydride, 1,1-bis(2,3 1,2,5,6-naphthalenetetracarboxylic dianhydride, 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride, 9,9-bis{4-(3,4-dicarboxyphenoxy)phenyl}fluorene dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 2,3,5,6-pyridinetetracarboxylic dianhydride, bis(3,4-dicarboxyphenyl)ethane dianhydride, bis(3,4-dicarboxyphenyl)methane dianhydride, bis(2,3-dicarboxyphenyl)methane dianhydride, bis(3,4-dicarboxyphenyl)sulfone dianhydride, bis(3,4-dicarboxyphenyl)ether dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride, 9,9-bis{4-(3,4-dicarboxyphenoxy)phenyl}fluorene dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 2,3,5,6-pyridinetetracarboxylic dianhydride tetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalenesuccinic dianhydride, 5-(2,5-dioxotetrahydrofuryl)-3-methyl-3-cyclohexene-1,2-dicarboxylic dianhydride, 2,3,5-tricarboxy-2-cyclopentanetetracarboxylic dianhydride, Examples of such compounds include, but are not limited to, norbornane acetic dianhydride, bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 2,3,4,5-tetrahydrofuran tetracarboxylic dianhydride, 3,5,6-tricarboxy-2-norbornane acetic dianhydride, 1,3,3a,4,5,9b-hexahydro-5(tetrahydro-2,5-dioxo-3-furanyl)naphtho[1,2-c]furan-1,3-dione, and acid dianhydrides having the structure shown in the formula below, as well as compounds in which some of the hydrogen atoms of these aromatic rings or hydrocarbons are substituted with alkyl groups having 1 to 10 carbon atoms. These may be used alone or in combination of two or more.

In the above structure, R ⁸ represents an oxygen atom, C(CH ₃ ) ₂ or SO ₂ , and R ⁹ to R ¹² represent a hydrogen atom, a hydroxyl group or a thiol group.

The component (A) may contain a diamine residue other than the alicyclic diamine residue having the structure represented by any one of the formulas (2) to (4).
For example, the inclusion of a dimethylsiloxane structure or a diphenyl ether structure can impart high elongation, and the inclusion of a biphenyl group can improve UV ablation properties. Other examples include the introduction of a phenolic hydroxyl group to impart alkali solubility, and the introduction of a polycyclic aromatic group or a heavy element to increase the refractive index.

Specific examples include 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl methane, 4,4'-diaminodiphenyl methane, 3,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfide, 1,4-bis(4-aminophenoxy)benzene, m-phenylenediamine, p-phenylenediamine, 1,5-naphthalenediamine, 2,6-naphthalenediamine, bis(4-aminophenoxyphenyl)sulfone, bis(3-aminophenoxyphenyl)sulfone, bis(4-aminophenoxy)biphenyl, bis{4-(4-aminophenoxy)furan phenyl} ether, 1,4-bis(4-aminophenoxy)benzene, benzidine, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-diethyl-4,4'-diaminobiphenyl, 2,2'-ditrifluoromethyl-4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-diethyl-4,4'-diaminobiphenyl, 3,3'-ditrifluoromethyl-4,4'-diaminobiphenyl, 2,2',3,3'-tetramethyl-4,4'-diaminobiphenyl, 3,3',4,4'-tetramethyl-4,4'-diaminobiphenyl, bis(3-amino-4-hydroxyphenyl)sulfone, bis(3-amino-4-hydroxyphenyl)propane, bis( Aromatic diamines such as bis(3-amino-4-hydroxyphenyl)methylene, bis(3-amino-4-hydroxyphenyl)ether, bis(3-amino-4-hydroxy)biphenyl, and bis(3-amino-4-hydroxyphenyl)fluorene, bis(3-aminopropyl)tetramethyldisiloxane, and bis(p-aminophenyl)octamethylpentasiloxane, as well as ethylenediamine, 1,3-diaminopropane, 2-methyl-1,3-propanediamine, 1,4-diaminobutane, 1,5-diaminopentane, 2-methyl-1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,11-diaminohexane, and the like. Diaminoundecane, 1,12-diaminododecane, 1,2-bis(2-aminoethoxy)ethane, KH-511, ED-600, ED-900, ED-2003, EDR-148, EDR-176, D-200, D-400, D-2000, THF-100, THF-140, THF-170, RE-600, RE-900, RE-2000, RP-40 Examples of the diamines include, but are not limited to, aliphatic diamines such as RP-5, RP-409, RP-2005, RP-2009, RT-1000, HE-1000, HT-1100, and HT-1700 (all trade names, manufactured by HUNTSMAN Co., Ltd.), and compounds in which some of the hydrogen atoms of the aromatic rings or hydrocarbons are substituted with alkyl groups having 1 to 10 carbon atoms. The other diamines to be copolymerized can be used as they are, or as the corresponding diisocyanate compounds or trimethylsilylated diamines. Two or more of these diamine components may also be used in combination.

The component (A) preferably has a biphenyl structure.
The biphenyl structure provides a cured film with high strength and high elongation, and improves ablation processability by UV laser. A method for introducing a biphenyl structure includes a method using an acid component and/or a diamine component having a biphenyl structure as a monomer.

The acid component may be any of the specific examples of acid anhydrides mentioned above that have a biphenyl structure. Specific examples include 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,3,3',4'-biphenyltetracarboxylic dianhydride, and 2,2',3,3'-biphenyltetracarboxylic dianhydride.

The diamine component may be any of the specific examples of diamines mentioned above that have a biphenyl structure. Specific examples include benzidine, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-diethyl-4,4'-diaminobiphenyl, 2,2'-ditrifluoromethyl-4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-diethyl-4,4'-diaminobiphenyl, 3,3'-ditrifluoromethyl-4,4'-diaminobiphenyl, 2,2',3,3'-tetramethyl-4,4'-diaminobiphenyl, and 3,3',4,4'-tetramethyl-4,4'-diaminobiphenyl.

The component (A) preferably contains a polyamic acid ester structure.
By having a polyamic acid ester structure, the depolymerization reaction of the (A) component can be suppressed during thermal curing, so that a cured film with high tensile elongation and breaking strength can be obtained. In addition, when the (A) component is a polyamic acid, metal diffusion occurs due to the interaction between the carboxylic acid and the metal wiring, but the content of the metal component is reduced by esterification, and a high-resolution pattern without residue can be obtained in ablation processing using a UV laser. As the polyamic acid ester structure, a structure in which R ⁷ in the formula (5) is an organic group having 1 to 20 carbon atoms can be mentioned. Since low-temperature curing properties and curing shrinkage can be suppressed, it is more preferable that R ⁷ is a methyl group. It is more preferable that the esterification rate of the carboxylic acid residue containing R ⁷ is 10% or more and less than 90%. Note that the carboxylic acid residue includes an imidized portion. When the imidization is 10%, the esterification rate is less than 90%. In terms of the balance between metal adhesion, ablation processing residue, and shape, the esterification rate of the carboxylic acid residue is preferably 10% or more, and more preferably 40% or more.

For the above-mentioned esterification, it is preferable to use 130 mol % to 200 mol % of the compound represented by formula (6) or formula (7) relative to 100 mol % of all carboxylic acid residues in the structural units derived from the (A) component structure. This is preferable because it can promote both esterification and imidization.

In formula (6), R ¹³ represents a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms, and is preferably a hydrogen atom from the viewpoint of reactivity. R ¹⁴ represents a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms, and is preferably a nitrogen-containing organic group.
Specifically, a dimethylamino group is preferred in terms of reactivity. In formula (6), a plurality of R ¹⁵ each independently represents a monovalent organic group having 1 to 20 carbon atoms.

In formula (7), R ¹⁶ represents a divalent cyclic organic group having 1 to 20 carbon atoms, and among these, a nitrogen-containing cyclic organic group is preferable. Each of the multiple R ¹⁷ independently represents a monovalent organic group having 1 to 20 carbon atoms. R ¹⁵ in formula (6) and R ¹⁷ in formula (7) are functional groups of the ester group of component (A), and a substituent to be introduced can be selected.

In addition, in order to improve the storage stability of the resin composition of the present invention and to exhibit various functions, the main chain ends of component (A) may be blocked with a terminal blocking agent. Examples of terminal blocking agents include known ones such as monoamines, acid anhydrides, monocarboxylic acids, monoacid chloride compounds, monoalcohols, and monoactive ester compounds. From the viewpoint of solubility in the developer and the mechanical properties of the resulting cured film, the introduction ratio of the terminal blocking agent is preferably 0.1 mol% to 60 mol%, and particularly preferably 5 mol% to 50 mol%. Multiple terminal blocking agents may be reacted to introduce multiple different terminal groups.

As the monoamine used as the terminal blocking agent, known compounds can be used, such as M-600, M-2070 (all trade names, manufactured by HUNTSMAN Co., Ltd.), aniline, 2-ethynylaniline, 3-ethynylaniline, 4-ethynylaniline, 2-aminobenzoic acid, 3-aminobenzoic acid, 4-aminobenzoic acid, 4-aminosalicylic acid, 2-aminophenol, 3-aminophenol, and 4-aminophenol. Two or more of these may be used.

As the acid anhydride, monocarboxylic acid, monoacid chloride compound, and monoactive ester compound, known compounds can be used, but examples of suitable compounds include acid anhydrides such as phthalic anhydride, maleic anhydride, nadic anhydride, cyclohexanedicarboxylic anhydride, and itaconic anhydride, monocarboxylic acids such as 3-carboxyphenol, 4-carboxyphenol, 1-hydroxy-7-carboxynaphthalene, and 1-hydroxy-6-carboxynaphthalene, and active ester compounds in which the carboxyl groups of these compounds are esterified. Two or more of these compounds may also be used.

As the monoalcohol used as the terminal blocking agent, aliphatic alcohols such as methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, and 1-pentanol, or monoalcohols derived from alkylene oxides such as ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, triethylene glycol monomethyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, and tripropylene glycol monomethyl ether can be used. Two or more of these may be used.

In addition, the various residues introduced into component (A) used in the present invention can be easily detected by known analytical methods such as NMR.

The weight average molecular weight of component (A) is preferably 5,000 or more and 100,000 or less. By making the weight average molecular weight 5,000 or more as calculated using polystyrene by GPC (gel permeation chromatography), mechanical properties such as elongation after curing, strength at break, and elastic modulus can be improved. In order to obtain better mechanical properties, a weight average molecular weight of 20,000 or more is more preferable. In addition, when component (A) contains two or more types of resins, it is sufficient that the weight average molecular weight of at least one of them is within the above range.

Component (A) can be obtained, for example, by the following known polymerization method. First, diamine, acid dianhydride, and other copolymerization components are dissolved in an organic solvent at room temperature, or at an elevated temperature if necessary, and then heated to polymerize. From the viewpoint of the stability of the solution during the reaction, it is preferable to dissolve the highly soluble diamine compound first. If necessary, other copolymerization components are added, and then an acid, acid anhydride, or monoamine that serves as an end-capping agent is added and polymerized. When the obtained component (A) is to be esterified, after the above polymerization, the carboxylic acid is reacted with an esterifying agent. In particular, when the above formula (6) or formula (7) is used, the imidization rate can be adjusted. The imidization rate may also be adjusted by adding an imidization promoter such as pyridine and stirring at 40 to 150°C.

After polymerization by the above method, other additives may be mixed to form a resin composition, but it is preferable to add it to a large amount of water or a mixture of methanol and water, precipitate it, filter, dry, and isolate it. The drying temperature is preferably 40 to 100°C, and more preferably 50 to 80°C. This operation removes unreacted monomers and oligomer components such as dimers and trimers, improving the film properties after thermal curing.

In the present invention, the imidization ratio can be easily determined, for example, by the following method. First, the infrared absorption spectrum of the polymer is measured to confirm the presence of absorption peaks (near 1780 cm ^-1 and 1377 cm ^{-1) of the imide structure resulting from polyimide. Next, the polymer is heat-treated at 350°C for 1 hour, and a sample having an imidization ratio of 100% is subjected to infrared absorption spectrum measurement. The peak intensities near 1377 cm- 1} of the resin before and after the heat treatment are compared to calculate the content of imide groups in the resin before the heat treatment, thereby determining the imidization ratio.

Examples of organic solvents used in the polymerization of component (A) include amides such as N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, N,N'-dimethylpropyleneurea, N,N-dimethylisobutyric acid amide, methoxy-N,N-dimethylpropionamide, γ-butyrolactone, γ-valerolactone, δ-valerolactone, γ-caprolactone, ε-caprolactone, α-methyl-γ-butyrolactone, Examples include, but are not limited to, cyclic esters such as lactones, carbonates such as ethylene carbonate and propylene carbonate, glycols such as triethylene glycol, phenols such as m-cresol and p-cresol, acetophenone, 1,3-dimethyl-2-imidazolidinone, sulfolane, dimethyl sulfoxide, tetrahydrofuran, dimethyl sulfoxide, propylene glycol monomethyl ether acetate, and ethyl lactate.

The resin composition of the present invention contains a solvent (B). Examples of the solvent include polar aprotic solvents such as N-methyl-2-pyrrolidone, γ-butyrolactone, γ-valerolactone, δ-valerolactone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethylsulfoxide, 1,3-dimethyl-2-imidazolidinone, N,N'-dimethylpropyleneurea, N,N-dimethylisobutyric acid amide, and methoxy-N,N-dimethylpropionamide, ethers such as tetrahydrofuran, dioxane, propylene glycol monomethyl ether, and propylene glycol monoethyl ether, ketones such as acetone, methyl ethyl ketone, and diisobutyl ketone, esters such as ethyl acetate, butyl acetate, isobutyl acetate, propyl acetate, propylene glycol monomethyl ether acetate, and 3-methyl-3-methoxybutyl acetate, alcohols such as ethyl lactate, methyl lactate, diacetone alcohol, and 3-methyl-3-methoxybutanol, and aromatic hydrocarbons such as toluene and xylene. Two or more of these may be contained. Among these, amide-based solvents that have good solubility for component (A) are preferred, with N-methyl-2-pyrrolidone, N,N'-dimethylpropyleneurea, N,N-dimethylisobutyric acid amide, and methoxy-N,N-dimethylpropionamide being preferred.

The content of the solvent is preferably 100 parts by mass or more per 100 parts by mass of component (A) in order to dissolve component (A), and is preferably 1,500 parts by mass or less in order to form a coating film with a thickness of 1 μm or more.

The resin composition of the present invention may contain adhesion improvers, antioxidants, surfactants, etc., as long as the effects of the invention are not impaired.

The adhesion improver includes a heterocyclic compound containing a nitrogen atom for metal substrates, and a silane coupling agent for silicon substrates. Examples of the heterocyclic compound containing a nitrogen atom include imidazole, pyrazole, indazole, carbazole, pyrazoline, pyrazolidine, triazole, tetrazole, pyridine, piperidine, pyrimidine, pyrazine, triazine, cyanuric acid, isocyanuric acid, and derivatives thereof, and more specifically, 1H-benzotriazole, 4-methyl-1H-methylbenzotriazole, 5-methyl-1H-methylbenzotriazole, 4-carboxy-1H-benzotriazole, 5-carboxy-1H-benzotriazole, 1H-tetrazole, 5-methyl-1H-tetrazole, 5-phenyl-1H-tetrazole, etc.

The content of the heterocyclic compound containing a nitrogen atom is preferably 0.01 parts by mass or more and 5.0 parts by mass or less, and more preferably 0.05 parts by mass or more and 3.0 parts by mass or less, per 100 parts by mass of component (A). When the content of the heterocyclic compound containing a nitrogen atom is within this range, the developability and the stabilization effect of the base metal can be maintained at an appropriate level.

Examples of the silane coupling agent include trimethoxyaminopropylsilane, trimethoxycyclohexylepoxyethylsilane, trimethoxyvinylsilane, trimethoxythiolpropylsilane, trimethoxyglycidyloxypropylsilane, tris(trimethoxysilylpropyl)isocyanurate, and a reaction product of trimethoxyaminopropylsilane and an acid anhydride. The reaction product can be used in the form of an amide acid or an imidized state. Examples of the acid anhydride to be reacted include succinic anhydride, maleic anhydride, nadic anhydride, cyclohexanedicarboxylic anhydride, pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,2',3,3'-benzophenonetetracarboxylic dianhydride, and 4,4'-oxydiphthalic dianhydride. The preferred content of the silane coupling agent is 0.01 to 10 parts by mass per 100 parts by mass of component (A).

The inclusion of the antioxidant prevents yellowing of the cured film during the subsequent curing process and reduces the deterioration of mechanical properties such as elongation. It is also preferable because it has a rust-preventing effect on metal materials and can suppress oxidation of metal materials.

As the antioxidant, a hindered phenol-based antioxidant or a hindered amine-based antioxidant is preferred. Examples of hindered phenol-based antioxidants include, but are not limited to, Irganox 245, Irganox 3114, and Irganox 1010 (all trade names, manufactured by BASF Corporation), and 2,6-di(t-butyl)-p-cresol. Examples of hindered amine-based antioxidants include, but are not limited to, TINUVIN 144 and TINUVIN 292 (all trade names, manufactured by BASF Corporation), 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate, and 2,2,6,6-tetramethyl-4-piperidyl methacrylate. Other antioxidants include phenol, catechol, resorcinol, hydroquinone, 4-t-butylcatechol, 2,6-di(t-butyl)-p-cresol, phenothiazine, and 4-methoxyphenol. The content of the antioxidant is preferably 0.1 parts by mass or more and 10.0 parts by mass or less, and more preferably 0.3 parts by mass or more and 5.0 parts by mass or less, per 100 parts by mass of component (A). When the content of the antioxidant is within this range, the developability and the effect of suppressing discoloration due to curing can be appropriately maintained.

The surfactant makes the surface thickness of the cured film uniform, so that the refractive index of the surface becomes uniform, and a high-resolution pattern can be obtained during ablation processing by laser. Specifically, examples of the surfactant include fluorine-based surfactants such as "Florard" (registered trademark) manufactured by Sumitomo 3M Co., Ltd., "Megafac" (registered trademark) manufactured by DIC Corporation, and "Sulfron" (registered trademark) manufactured by Asahi Glass Co., Ltd., KP341 manufactured by Shin-Etsu Chemical Co., Ltd., DBE manufactured by Chisso Corporation, "Polyflow" (registered trademark) and "Granol" (registered trademark) manufactured by Kyoeisha Chemical Co., Ltd., and BYK manufactured by BYK-Chemie Co., Ltd., and acrylic polymer surfactants such as Polyflow manufactured by Kyoeisha Chemical Co., Ltd. Among these, acrylic polymer surfactants are preferred because they tend to be unevenly distributed on the film surface of the cured film due to their low compatibility with component (A). The surfactant is preferably contained in an amount of 0.01 to 10 parts by mass per 100 parts by mass of component (A).

The resin composition of the present invention may contain other resins as long as the properties of component (A) are not impaired, but non-fluorine-based resins are preferred. Fluorine-based resins refer to polytetrafluoroethylene, trichlorofluoroethylene, tetrafluoroethylene-hexafluoropropylene, polyvinylidene fluoride, polyvinyl fluoride, tetrafluoroethylene-perfluoroalkyl vinyl ether, tetrafluoroethylene-ethylene, and chlorotrifluoroethylene-ethylene resins. Fluorine does not absorb in the ultraviolet range, so even if it contains a resin or additive that absorbs in the ultraviolet range, it cannot be removed during ablation processing to form a fine pattern, leaving residue, and the interaction with molecular chains and metals is suppressed, resulting in a decrease in physical properties and a decrease in adhesion, so non-fluorine-based resins are preferred.

Specific examples of other resins include polyimide resins, polybenzoxazoles, polybenzoxazole precursors, polyamide resins, siloxane resins, maleimide resins, acrylic polymers copolymerized with acrylic acid, epoxy resins, novolac resins, resol resins, polyhydroxystyrene resins, and modified versions of these resins with crosslinking groups such as methylol groups, alkoxymethyl groups, and epoxy groups, as well as copolymers of these resins.

The viscosity of the resin composition of the present invention is preferably 2 to 5,000 mPa·s. The viscosity can be measured using an E-type rotational viscometer. By adjusting the solid content concentration so that the viscosity is 2 mPa·s or more, it becomes easy to obtain a desired film thickness. On the other hand, if the viscosity is 5,000 mPa·s or less, it becomes easy to obtain a highly uniform coating film. A resin composition having such a viscosity can be easily obtained, for example, by setting the solid content concentration to 5 to 60 mass%.

Next, the cured film obtained by curing the resin composition of the present invention will be described.
The cured film of the present invention is obtained by curing the resin composition of the present invention. The curing temperature is preferably 150°C or more and 350°C or less. In order to prevent influence on the substrate/semiconductor device and to obtain appropriate elongation/strength, 200°C or more and 250°C or less is more preferable. The curing device may be an oven, a hot plate, infrared irradiation, microwave irradiation, or the like, and is preferably performed for 20 minutes to several hours. In addition, the material may be directly put into a hot plate or oven or other equipment set at the curing temperature, but it may also be put into a curing equipment at around room temperature and heated stepwise. There is no particular limit to the temperature rise rate, but 0.5°C/min to 10°C/min is preferable. The atmosphere during curing may be under air or under an inert gas such as nitrogen, but under an inert gas is preferable, and in the case of under air, the curing temperature is preferably 250°C or less.

The imidization rate of the cured film of the present invention is preferably 97% or more and 100% or less from the viewpoints of chemical resistance and ablation processability with a UV laser described below.
Moreover, a cured film cured at a curing temperature of 200° C. to 250° C., which causes little damage to the substrate, is preferred.
The cured film of the present invention is preferably a cured film patterned by UV laser ablation. The cured film of the present invention has excellent ablation processability by UV laser. The reason is unclear, but it is presumed that the cured film is excellent in UV absorption because it is a polyimide obtained from an aromatic acid anhydride, has low water absorption so that it is unlikely to foam due to sudden heat generation, and has high breaking strength so that it is resistant to stress changes due to temperature shock around the laser irradiated area.

The electronic component of the present invention comprises the above-mentioned cured film.
Specifically, the electronic component may be provided with a cured film as an insulating film or a protective film.

Here, examples of electronic components include active components that have semiconductors, such as transistors, diodes, integrated circuits (ICs), and memories, as well as passive components, such as resistors, capacitors, and inductors. Electronic components also include sealed packages that are designed to improve the durability of these components, and modules that integrate multiple components. Electronic components that use semiconductors are also called semiconductor devices or semiconductor packages. Other examples include display panels and touch sensor panels.

Specific examples of cured films in electronic components include passivation films for semiconductors, surface protection films for semiconductor elements and TFTs (Thin Film Transistors), interlayer insulating films such as interlayer insulating films between rewirings in multilayer wiring for high-density packaging of 2 to 10 layers, insulating films for touch panel displays, protective films, and insulating layers for organic electroluminescent devices. However, the present invention is not limited to these and can have a variety of structures. Among these, it is preferably used as an interlayer insulating film in multilayer wiring for high-density packaging. This is because it has lower water absorption than conventional polyimides, so the parasitic components that are an issue when densified do not change, it can be cured at low temperatures, and it can be used as a substrate material for both organic and inorganic substrates, and it has high elongation and strength, so it has high resistance to cracking against stress caused by multilayering.

Next, the method for forming a pattern of the cured film of the present invention will be described.
The method for producing a pattern of a cured film includes the steps of applying the resin composition of the present invention to a substrate, volatilizing the solvent (B) at 80° C. or more and less than 150° C., curing the composition at 150° C. or more and 250° C. or less, and ablation processing with a UV laser.

First, the step of applying the resin composition of the present invention to a substrate will be described.
Examples of substrates include, but are not limited to, silicon wafers, ceramics, gallium arsenide, organic circuit boards, inorganic circuit boards, composite substrates of silicon wafers and sealing resins such as epoxy resins, and substrates on which circuit constituent materials are disposed.

Examples of organic circuit boards include glass substrate copper-clad laminates such as glass cloth/epoxy copper-clad laminates, composite copper-clad laminates such as glass nonwoven cloth/epoxy copper-clad laminates, temporary carrier substrates, heat-resistant/thermoplastic substrates such as polyetherimide resin substrates, polyetherketone resin substrates, and polysulfone resin substrates, and flexible substrates such as polyester copper-clad film substrates and polyimide copper-clad film substrates. Examples of inorganic circuit boards include glass substrates, ceramic substrates such as alumina substrates, aluminum nitride substrates, and silicon carbide substrates, and metal substrates such as aluminum-based substrates and iron-based substrates. Examples of circuit materials include conductors containing metals such as silver, gold, and copper, resistors containing inorganic oxides, low dielectrics containing glass-based materials and/or resins, high dielectrics containing resins and high-dielectric-constant inorganic particles, and insulators containing glass-based materials.

The surface condition of metal wiring on circuit boards, etc. changes when oxidized in air, so it is preferable to oxidize it in advance using oxygen plasma treatment or hydrogen peroxide solution.

Coating methods include spin coating using a spinner, spray coating, roll coating, screen printing, blade coater, die coater, calendar coater, meniscus coater, bar coater, roll coater, comma roll coater, gravure coater, screen coater, and slit die coater. The coating thickness varies depending on the coating method, the solids concentration of the composition, the viscosity, etc., but it is usually applied so that the film thickness after drying is 0.1 to 150 μm.

To improve adhesion between a substrate such as a silicon wafer and the resin composition, the substrate can be pretreated with the aforementioned silane coupling agent. For example, a solution in which the silane coupling agent is dissolved in a solvent such as isopropanol, ethanol, methanol, water, tetrahydrofuran, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, ethyl lactate, or diethyl adipate at a concentration of 0.5 to 20% by mass is used for surface treatment by spin coating, immersion, spray application, steam treatment, or the like. In some cases, a heat treatment up to 50°C to 300°C is then performed to promote the reaction between the substrate and the silane coupling agent.

Next, the step of volatilizing the solvent (B) at a temperature of 80° C. or higher and lower than 150° C. will be described.
The drying step for volatilizing the solvent is preferably carried out for 1 minute to several hours at a temperature in the range of 50° C. to 150° C. using an oven, a hot plate, infrared irradiation, microwave irradiation, etc. The drying atmosphere may be air or an inert gas such as nitrogen.

Next, the step of curing at 150° C. or higher and 250° C. or lower will be described.
The curing conditions are preferably 150°C or higher and 350°C or lower. In order to prevent the influence on the substrate/semiconductor device and to obtain appropriate elongation/strength, 200°C or higher and 250°C or lower are more preferable. The same equipment as that used for drying can be used for curing, and curing is preferably performed for 20 minutes to several hours. The material can be directly placed in equipment such as a hot plate or oven set at the curing temperature, but it can also be placed in the curing equipment at around room temperature and heated stepwise. There is no particular limit to the temperature rise rate, but 0.5°C/min to 10°C/min is preferable. The atmosphere during curing may be air or an inert gas such as nitrogen, but an inert gas is preferable. In addition, when the material is cured in air, the curing temperature is preferably 250°C or lower.

Next, the process of ablation using a UV laser will be described.
The cured film is irradiated with a UV laser to perform an ablation process, thereby forming a pattern in the desired position.

The irradiation conditions of this UV laser are not particularly limited, but typically excimer lasers such as ArF (193 nm), KrF (248 nm), XeCl (308 nm), XeCl (351 nm), and YAG laser (355 nm) light are used. Among these, excimer lasers are preferred because they are less susceptible to heat during processing and can form high-resolution patterns with via diameters of 5 μm or less. Processing with KrF (248 nm) is even more preferred because the wavelength of the UV laser provides an appropriate absorbance of the cured film, resulting in a high-resolution pattern without residue.

When forming a pattern, the UV laser light having an energy density of 5 to 10,000 mJ/ ^cm2 is irradiated onto the cured film-formed substrate for a predetermined time via an optical system having a reduction ratio of 0.1 to 20 times at a repetitive pulse rate of 1 to 3,000 Hz, either directly or using a patterning mask of a desired shape, to form a pattern.

The cured film of the resin composition of the present invention can have a rectangular tapered shape by setting the UV laser irradiation energy to 500 to 1000 mJ/ ^cm2 , and the tapered shape can be controlled by controlling the energy density to 100 or more and less than 500 mJ/ ^cm2 . This is preferable because it is easy to control the shape in an interlayer insulating film where different shapes are required for each layer due to differences in wiring thickness and pattern formation density.

In the present invention, the absorbance of the cured film when the resin composition is cured is preferably 0.05 to 0.9 per 1 μm of film thickness at the wavelength of the UV laser, and more preferably 0.07 to 0.3. This range is preferable because it is possible to form a pattern with the UV laser and shape abnormalities are unlikely to occur.

The cured film of the present invention can also be ablated with a carbon dioxide laser. Although the carbon dioxide laser has inferior resolution compared to the UV laser, the equipment cost is low and it is economical, so the carbon dioxide laser may be used in applications that do not require high resolution.

Next, an application example of the resin composition of the present invention to a semiconductor device having bumps will be described with reference to the drawings (Application Example 1). FIG. 1 is an enlarged cross-sectional view of a pad portion of a semiconductor device having bumps of the present invention. As shown in FIG. 1, a passivation film 3 is formed on an aluminum (hereinafter, Al) pad 2 for input/output on a silicon wafer 1, and a via hole is formed in the passivation film 3. Furthermore, an insulating film 4 is formed on the insulating film 3 as a pattern using the resin composition of the present invention, and a metal (Cr, Ti, etc.) film 5 is formed so as to be connected to the Al pad 2, and a metal wiring (Al, Cu, etc.) 6 is formed by electrolytic plating or the like. The metal film (Cr, Ti, etc.) 5 etches the periphery of the solder bump 10 to insulate each pad from the other. Furthermore, an insulating film 7 is formed on the insulating pad as a pattern using the resin composition of the present invention. A barrier metal 8 and a solder bump 10 are formed on the insulated pad. The resin of the present invention has excellent elongation, so the resin itself can deform, alleviating stress from the encapsulating resin during mounting, preventing damage to bumps, wiring, and low-k layers and providing a highly reliable semiconductor device.

2 shows a detailed method for manufacturing a semiconductor device. As shown in FIG. 2, 2a, an Al pad 2 for input/output and a passivation film 3 are formed on a silicon wafer 1, and an insulating film 4 is formed as a pattern using the resin composition of the present invention. Then, as shown in FIG. 2, 2b, a metal (Cr, Ti, etc.) film 5 is formed so as to be connected to the Al pad 2, and as shown in FIG. 2, 2c, a metal wiring (Al, Cu, etc.) 6 is formed by plating. Next, as shown in FIG. 2, 2d', the resin composition of the present invention is applied and cured, and then an ablation process is performed to form an insulating film 7 as a pattern as shown in FIG. 2, 2d. Further wiring (so-called rewiring) can be formed on the insulating film 7. When forming a multilayer wiring structure of two or more layers, the above steps can be repeated to form a multilayer wiring structure in which two or more rewiring layers are separated by an interlayer insulating film obtained from the resin composition of the present invention. There is no upper limit to the number of layers in the multilayer wiring structure, but a structure of 10 layers or less is often used. At this time, the resin composition of the insulating film 7 is processed into a thick film at the scribe line 9. When forming a multilayer wiring structure with three or more layers, the above steps can be repeated to form each layer.

Next, as shown in Fig. 2e and 2f, a barrier metal 8 and solder bumps 10 are formed. Then, the final dicing is performed along the scribe lines 9 to separate the chips.

Next, an application example 2 to a semiconductor device having bumps using the resin composition of the present invention will be described with reference to the drawings. FIG. 3 is an enlarged cross-sectional view of the pad portion of a semiconductor device having an insulating film of the present invention, and has a structure called a fan-out wafer level package (fan-out WLP). As in the above application example 1, a silicon wafer 1 on which an Al pad 2 and a passivation film 3 are formed is diced and cut into chips, and then sealed with resin 11. An insulating film 4 is formed as a pattern using the resin composition of the present invention over this sealing resin 11 and the chip, and further a metal (Cr, Ti, etc.) film 5 and metal wiring 6 are formed. Then, a barrier metal 8 and a solder bump 10 are formed in the opening of the insulating film 7 formed on the sealing resin outside the chip. The fan-out WLP is a semiconductor package in which an extension portion is provided around the semiconductor chip using a sealing resin such as an epoxy resin, rewiring is performed from the electrodes on the semiconductor chip to the extension portion, and solder balls are also mounted on the extension portion to ensure the required number of terminals.

Fan-out WLP is a type of package that is created using a process called RDL-first, in which a temporary bonding material is placed on a support substrate as an interlayer insulating film between rewirings, a silicon chip and sealing resin are placed on top of that, and then the support substrate on which the temporary bonding material is placed is peeled off from the rewirings. The resin composition of the present invention can be used in the same way in RDL-first.

Next, a third application example of the inductor device coil component using the resin composition of the present invention will be described with reference to the drawings. FIG. 4 is a cross-sectional view of a coil component having an insulating film of the present invention. As shown in FIG. 4, an insulating film 13 is formed on a substrate 12, and an insulating film 14 is formed as a pattern on the insulating film 13. Ferrite or the like is used as the substrate 12. The resin composition of the present invention may be used for either the insulating film 13 or the insulating film 14. A metal (Cr, Ti, etc.) film 15 is formed in the opening of this pattern, and a metal wiring (Ag, Cu, etc.) 16 is plated on the metal wiring 15. The metal wiring 16 (Ag, Cu, etc.) is formed in a spiral shape. By repeating steps 13 to 16 multiple times and stacking them, the function of a coil can be provided. Finally, the metal wiring 16 (Ag, Cu, etc.) is connected to an electrode 18 by a metal wiring 17 (Ag, Cu, etc.) and sealed with a sealing resin 19.

The antenna element of the present invention is an antenna element comprising at least one or more antenna wirings and the cured film of the present invention, wherein the antenna wiring includes at least one or more antennas selected from the group consisting of a meandering loop antenna, a coiled loop antenna, a meandering monopole antenna, a meandering dipole antenna, and a microstrip antenna, the area occupied by each antenna part in the antenna wiring is 1000 ^mm2 or less, and the cured film is preferably an insulating film that provides insulation between the ground and the antenna wiring.

Here, the antenna element refers to an electronic component that utilizes passive components such as resistors, inductors, and capacitors and has the function of transmitting and receiving radio waves.
The material used for the antenna wiring is not particularly limited as long as it has conductivity, and examples thereof include metal materials such as copper, gold, silver, platinum, aluminum, molybdenum, and titanium. These may be laminates or alloys of different metals, or may be composites with organic substances such as polymers. In addition, carbon materials such as graphite, graphene, and carbon nanotubes, and conductive polymers may be used. Among these, copper is preferred because of its excellent cost, conductivity, and stability.

The antenna element of the present invention will be specifically described with reference to FIG. 5. FIG. 5 is a schematic diagram of a coplanar-feed type microstrip antenna, which is a type of planar antenna. 5a shows a cross-sectional view, and 5b shows a top view. First, the formation method will be described. The thermosetting resin composition of the present invention is applied onto copper foil and pre-baked. Next, copper foil is laminated and thermally cured to form a cured film having copper foil on both sides. After that, patterning is performed by the subtractive method, and an antenna element having an antenna pattern of copper wiring of a microstrip line (MSL) as shown in FIG. 5 is obtained.

Next, the antenna pattern in FIG. 5 will be described. In 5a, 55 indicates the ground (all over), and 56 indicates an insulating film that becomes the substrate of the antenna. The upper layers 51 to 53 indicate the cross section of the antenna wiring obtained by the patterning. The ground wiring thickness J and the antenna wiring thickness K can be any thickness depending on the impedance design, but are generally 2 to 20 μm. In 5b, 51 indicates the antenna part, 52 indicates the matching circuit, 53 indicates the MSL feed line, and 54 indicates the feeding point. In order to match the impedance of the antenna part 51 and the MSL feed line 53, the length M of the matching circuit 52 has a length of 1/4 λr (λr = (wavelength of transmitted radio wave) / (dielectric constant of insulating material) ^1/2 ). In addition, the width W and length L of the antenna part 51 are designed to be 1/2 λr. The antenna part length L may be 1/2 λr or less depending on the impedance design.

The cured film of the present invention has low water absorption, so that an antenna element with small characteristic variations due to the environment can be provided. In addition, due to these characteristics, an antenna element using the insulating film of the present invention is particularly suitable as a high-frequency antenna, and a small antenna element can be formed by setting the area (=L×W) of the antenna part to a size of 1000 ^mm2 or less. In this way, an antenna element for high frequencies can be obtained.

Furthermore, the semiconductor package of the present invention is a semiconductor package comprising at least a semiconductor element, a redistribution layer, a sealing resin, and an antenna wiring, the antenna wiring includes at least one type selected from the group consisting of a meandering loop antenna, a coiled loop antenna, a meandering monopole antenna, a meandering dipole antenna, and a microstrip antenna, the area occupied by each antenna portion in the antenna wiring is 1000 ^mm2 or less, the insulating layer of the redistribution layer and/or the sealing resin includes the cured film of the present invention, and it is preferable that the sealing resin is located between a ground and the antenna wiring.

Materials used for the antenna wiring include those described in the description of the antenna element above. In addition, examples of semiconductor elements include an integrated circuit (RFIC) that processes signals transmitted and received by the antenna, and may have semiconductor elements such as an amplifier and a noise filter. From the viewpoints of cost and reliability, the rewiring layer is preferably made up of 1 to 3 layers of metal wiring and 1 to 4 layers of insulating layers, but is not limited thereto. The insulating layer is preferably the cured film of the present invention. The sealing resin is preferably the cured film of the present invention, but when used in the insulating layer of the rewiring layer, there are no restrictions and any sealing agent can be used, and a mixture of epoxy resin and inorganic filler is common.

A semiconductor package having an IC chip (semiconductor element), a rewiring layer, a sealing resin, and an antenna wiring will be described. FIG. 6 is a schematic diagram of a cross section of a semiconductor package having an IC chip (semiconductor element), a rewiring, a sealing resin, and an antenna element. On the electrode pad 602 of the IC chip 601, a rewiring layer (two copper layers, three insulating layers) is formed by copper wiring 609 and an insulating film 610 formed by the cured film of the present invention. The thickness of the copper wiring is preferably 2 to 10 μm in order to reduce noise. The thickness of the insulating layer can be set according to the thickness of the copper wiring, and it is preferable to make it 2 to 5 μm thicker than the copper wiring from the viewpoint of insulation. A barrier metal 611 and a solder bump 612 are formed on the pad of the rewiring layer (copper wiring 609 and insulating film 610). In order to seal the IC chip, a first sealing resin 608 made of the cured film of the present invention is formed, and a copper wiring 609 serving as a ground for the antenna is further formed thereon. A first via wiring 607 is formed to connect the ground 606 and the rewiring layer (copper wiring 609 and insulating film 610) through a via hole formed in the first sealing resin 608. A second sealing resin 605 made of the cured film of the present invention is formed on the first sealing resin 608 and the ground 606, and a planar antenna wiring 604 is formed thereon. A second via wiring 603 is formed to connect the planar antenna wiring 604 and the rewiring layer (copper wiring 609 and insulating film 610) through a via hole formed in the first sealing resin 608 and the second sealing resin 605. The thickness of each layer of the insulating film 610 is preferably 10 to 20 μm, and the first sealing resin and the second sealing resin are preferably 50 to 200 μm and 100 to 400 μm, respectively. Since the cured film of the present invention has low water absorption, the semiconductor package having the obtained antenna element has small characteristic fluctuation due to the environment and is highly reliable.

The present invention will be described below with reference to examples, but the present invention is not limited to these examples. First, the evaluation methods for each example and comparative example will be described. For the evaluation, the resin composition (hereinafter referred to as varnish) of each example was used, which had been previously filtered through a polytetrafluoroethylene (PTFE) filter (manufactured by Sumitomo Electric Industries, Ltd.) with an average pore size of 1 μm.

(1) Molecular weight measurement and esterification rate measurement The weight average molecular weight (Mw) of component (A) was confirmed using a GPC (gel permeation chromatography) device Waters 2690-996 (manufactured by Japan Waters Co., Ltd.). Measurements were performed using N-methyl-2-pyrrolidone (hereinafter referred to as NMP) as the developing solvent, and the weight average molecular weight (Mw) and dispersity (PDI = Mw/Mn) were calculated in terms of polystyrene.

The esterification rate of component (A) was measured using a 400 MHz ^1H -NMR (nuclear magnetic resonance) device (AL-400, manufactured by JEOL Ltd.) in a deuterated dimethyl sulfoxide solution with 16 cumulative measurements, and the esterification rate was calculated based on the integral value of the protons of the esterified substituents.

(2) Measurement of imidization rate of cured film The varnish was spin-coated on a 4-inch silicon wafer and dried at 120°C for 3 minutes. When a varnish containing a photobase generator was used, the entire surface was exposed to 300 mJ/ ^cm2 using PLA, and the temperature was raised to the curing temperature shown in Table 2 at a rate of 3.5°C/min using an inert oven CLH-21CD-S (manufactured by Koyo Thermo Systems Co., Ltd.) with an oxygen concentration of 20 ppm or less, under the curing conditions shown in Table 2. Furthermore, the infrared absorption spectrum was measured, and the presence of absorption peaks of the imide structure (near 1780 cm ^-1 and 1377 cm ^-1 ) was confirmed.
Next, the coating film was cured at 350° C. for 1 hour, and the infrared absorption spectrum of the sample with an imidization rate of 100% was measured, and the content of imide groups in the resin before heat treatment was calculated by comparing the peak intensities at about 1377 cm ⁻¹ of the resin before and after curing at 350° C., thereby determining the imidization rate. The infrared absorption spectrum was measured using an "FT-720" (trade name, manufactured by Horiba, Ltd.) as a measuring device.

(3) Measurement of elongation at break and strength at break of cured film The varnish was applied to a 6-inch silicon wafer by spin coating using a coating and developing apparatus ACT-8 so that the film thickness after pre-baking at 120 ° C. for 3 minutes was 11 μm, and then pre-baked. When a varnish containing a photobase generator was used, the entire surface was exposed to 300 mJ / cm ² using PLA, and the temperature was raised to the curing temperature shown in Table 2 at a rate of 3.5 ° C. / min using an inert oven CLH-21CD-S (manufactured by Koyo Thermo Systems Co., Ltd.) with an oxygen concentration of 20 ppm or less, and curing was performed for 1 hour at the curing temperature shown in Table 2. When the temperature reached 50 ° C. or less, the silicon wafer was removed and immersed in 45 mass % hydrofluoric acid for 5 minutes to peel off the cured film of the resin composition from the wafer. The film was cut into strips 1.5 cm wide and 9 cm long, and was stretched at a tensile speed of 50 mm/min (chuck spacing = 2 cm) at room temperature of 23.0°C and humidity of 45.0% RH using a Tensilon RTM-100 (manufactured by Orientec Co., Ltd.) to measure the elongation at break (%) and strength at break (MPa). Measurements were performed on 10 strips per specimen, and the average of the top 5 highest values was calculated from the results (significant figures = 2 digits).

(4) Measurement of water absorption rate A free-standing cured film was prepared in the same manner as in "(2) Measurement of elongation at break and strength at break of cured film" above, and treated for 20 hours under saturated conditions of 23°C, 100% RH and 1 atm using a high temperature and humidity tester (HAST CHAMBER EHS-211MD, manufactured by Tabai Spec Co., Ltd.), and then this film was held at 120°C for 30 minutes in a thermogravimetric analyzer (TGA). The water absorption rate was calculated from the weight loss rate before and after heating.

(5) Pattern Evaluation The varnish was applied by spin coating using a coating and developing apparatus ACT-8 (manufactured by Tokyo Electron Co., Ltd.) on an 8-inch silicon wafer on which a 100 nm copper sputtered film had been formed, and pre-baked at 120°C for 3 minutes. When a varnish containing a photobase generator was used, the entire surface was exposed to 300 mJ/ ^cm2 using PLA, and the temperature was raised to the curing temperature shown in Table 2 at a rate of 3.5°C/min using an inert oven CLH-21CD-S (manufactured by Koyo Thermo Systems Co., Ltd.) at an oxygen concentration of 20 ppm or less, and curing was performed for 1 hour at the curing temperature shown in Table 2. The obtained cured film having a thickness of 10 μm was irradiated with a carbon dioxide laser (wavelength 10600 nm) or a KrF excimer laser (wavelength 248 nm), which is a UV laser, to form a via pattern at an irradiation dose of 600 mJ/ ^cm2 . The minimum via pattern diameter (μm) that can be opened was taken as the resolution.

(6) Evaluation of Adhesion to Copper Substrate Adhesion to metallic copper was evaluated by the following method.

First, a cured film was formed on a copper-plated metal substrate with a thickness of approximately 3 μm in the same manner as in "(2) Measurement of the imidization rate of the cured film" above. Using a single-edged blade, 10 rows and 10 columns of cuts were made in the resulting cured film on the copper substrate at 1 mm intervals. The adhesive properties between the metal material and the cured resin film were then evaluated based on how many of the 100 squares peeled off when peeled off using "Scotch Tape" (registered trademark). In the peel test, 0 peeled pieces were scored as 5, 1 to 10 pieces were scored as 4, 10 to 30 pieces were scored as 3, 30 to 50 pieces were scored as 2, and 50 pieces or more were scored as 1.

The fewer the number of peeled pieces, the better the adhesion.

(7) Storage Stability of Varnish The viscosity of the varnish immediately after preparation and after standing at 23° C. for 2 weeks was measured, and the rate of change in viscosity before and after standing was calculated.
The smaller the rate of change in viscosity before and after standing, the better the storage stability.

(Synthesis Example 1) Synthesis of (A-1) Under a dry nitrogen stream, 4,4'-methylenebis(cyclohexylamine) (HM) (21.0 g, 0.1 mol) was dissolved in 250 g of N-methyl-2-pyrrolidone (NMP), and then decamethylene bistrimellitate dianhydride (10BA) (52.3 g, 0.1 mol) was added and reacted at 40°C for 1 hour. Thereafter, the temperature was raised to 80°C and further stirred for 2 hours. After completion of the reaction, the mixture was cooled to room temperature and diluted with NMP to a solid content concentration of 20 wt%, to obtain an NMP solution of a polyimide precursor polymer (A-1) (solid content concentration 20 wt%). The esterification rate of the obtained (A-1) was 0%, the weight average molecular weight was 50,500, and the PDI was 2.4.

Synthesis Example 2 Synthesis of (A-2) An NMP solution (solid content concentration 20 wt%) of a polyimide precursor polymer (A-2) was obtained in the same manner as in Synthesis Example 1, except that trans-cyclohexanediamine (t-CHDA) (11.4 g, 0.1 mol) was used instead of HM. The esterification rate of the obtained (A-2) was 0%, the weight average molecular weight was 52,500, and the PDI was 2.5.

Synthesis Example 3 Synthesis of (A-3) Except for using 2,2'-trifluoromethyl-4,4'-aminobicyclohexane (H-TFMB) (33.2 g, 0.1 mol) instead of HM, an NMP solution (solid content concentration 20 wt%) of a polyimide precursor polymer (A-3) was obtained in the same manner as in Synthesis Example 1. The esterification rate of the obtained (A-3) was 0%, the weight average molecular weight was 53,000, and the PDI was 2.5.

Synthesis Example 4 Synthesis of (A-4) Except for using hexadecamethylene bistrimellitate dianhydride (16BA) (60.7 g, 0.1 mol) instead of 10BA, an NMP solution (solid content concentration 20 wt%) of a polyimide precursor polymer (A-4) was obtained in the same manner as in Synthesis Example 1. The esterification rate of the obtained (A-4) was 0%, the weight average molecular weight was 50,000, and the PDI was 2.3.

Synthesis Example 5 Synthesis of (A-5) Except for using hexamethylene bistrimellitate dianhydride (6BA) (46.6 g, 0.1 mol) instead of 10BA, an NMP solution (solid content concentration 20 wt%) of a polyimide precursor polymer (A-5) was obtained in the same manner as in Synthesis Example 1. The esterification rate of the obtained (A-5) was 0%, the weight average molecular weight was 49,000, and the PDI was 2.2.

(Synthesis Example 6) Synthesis of (A-6) Under a dry nitrogen stream, 4,4'-methylenebis(cyclohexylamine) (HM) (21.0 g, 0.1 mol) was dissolved in 250 g of dimethyl sulfoxide (DMSO), and then decamethylenebistrimellitic acid amide dianhydride (10BAm) (52.1 g, 0.1 mol) was added and reacted at 40 ° C. for 1 hour. Thereafter, the temperature was raised to 80 ° C. and further stirred for 2 hours. After completion of the reaction, the mixture was cooled to room temperature and diluted with DMS to a solid content concentration of 20 wt%, to obtain a DMSO solution of a polyimide precursor polymer (A-6) (solid content concentration 20 wt%). The esterification rate of the obtained (A-5) was 0%, the weight average molecular weight was 52,000, and the PDI was 2.4. This polymerization was carried out in DMSO because thickening occurred due to insufficient solubility when the solvent was NMP.

Synthesis Example 7 Synthesis of (A-7) A DMSO solution (solid content concentration 20 wt%) of a polyimide precursor polymer (A-7) was obtained in the same manner as in Synthesis Example 6, except that decamethylene bistrimellitic acid thioester dianhydride (10BS) (55.5 g, 0.1 mol) was used instead of 10BAm. The esterification rate of the obtained (A-7) was 0%, the weight average molecular weight was 45,000, and the PDI was 2.2.

Synthesis Example 8 Synthesis of (A-8) Except for changing the amount of 10BA to (26.1 g, 0.05 mol) and further using 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) (14.7 g, 0.05 mol) as the acid component, an NMP solution (solid content concentration 20 wt%) of a polyimide precursor polymer (A-8) was obtained in the same manner as in Synthesis Example 1. The esterification rate of the obtained (A-8) was 0%, the weight average molecular weight was 52,000, and the PDI was 2.4.

Synthesis Example 9 Synthesis of (A-9) Except for changing the amount of 10BA to 15.7 g (0.03 mol) and further using BPDA (20.6 g, 0.07 mol) as the acid component, an NMP solution (solid content concentration 20 wt%) of a polyimide precursor polymer (A-9) was obtained in the same manner as in Synthesis Example 1. The esterification rate of the obtained (A-9) was 0%, the weight average molecular weight was 53,000, and the PDI was 2.5.

Synthesis Example 10 Synthesis of (A-10) Except for changing the amount of HM charged to 10.5 g (0.05 mol) and further using 2,2'-ditrifluoromethyl-4,4'-diaminobiphenyl (TFMB) (16.0 g, 0.05 mol) as the diamine component, an NMP solution (solid content concentration 20 wt%) of a polyimide precursor polymer (A-10) was obtained in the same manner as in Synthesis Example 1. The esterification rate of the obtained (A-10) was 0%, the weight average molecular weight was 54,000, and the PDI was 2.5.

Synthesis Example 11 Synthesis of (A-11) Except for changing the amount of HM charged to 6.3 g (0.03 mol) and further using TFMB (22.4 g, 0.07 mol) as the diamine component, an NMP solution (solid content concentration 20 wt%) of a polyimide precursor polymer (A-11) was obtained in the same manner as in Synthesis Example 1. The esterification rate of the obtained (A-11) was 0%, the weight average molecular weight was 54,000, and the PDI was 2.5.

(Synthesis Example 12) Synthesis of (A-12) Under a dry nitrogen stream, HM (21.0 g, 0.1 mol) was dissolved in 250 g of NMP, 10BA (52.3 g, 0.1 mol) was added, and the mixture was reacted at 40° C. for 1 hour. The temperature was then raised to 80° C., and the mixture was stirred for another 2 hours. Then, a solution of N,N-dimethylformamide dimethyl acetal (35.8 g, 0.3 mol) diluted with 10 g of NMP was added dropwise over 10 minutes. After the addition, the mixture was stirred at 40° C. for 3 hours. After the reaction was completed, the solution was poured into 2 L of water, and the precipitate of the polymer solid was collected by filtration. The polymer solid was dried in a vacuum dryer at 50° C. for 72 hours to obtain a polyimide precursor (A-12). The esterification rate of the resin thus obtained by methyl groups was 50%. The weight average molecular weight was 55,300, and the PDI was 2.4.

Synthesis Example 13 Synthesis of (A-13) Except for using pyromellitic anhydride (PMDA) (21.2 g, 0.1 mol) instead of 10BA, an NMP solution (solid content concentration 20 wt%) of a polyimide precursor polymer (A-13) was obtained in the same manner as in Synthesis Example 1. The esterification rate of the obtained (A-13) was 0%, the weight average molecular weight was 50,000, and the PDI was 2.3.

Synthesis Example 14 Except for using 4,4'-diaminodiphenyl ether (ODA) (20.2 g, 0.1 mol) instead of the synthetic HM of (A-14), an NMP solution (solid content concentration 20 wt%) of a polyimide precursor polymer (A-14) was obtained in the same manner as in Synthesis Example 1. The esterification rate of the obtained (A-14) was 0%, the weight average molecular weight was 55,000, and the PDI was 2.5.
(Synthesis Example 15) Synthesis of (A-15) Under a dry nitrogen stream, 62.04 g (0.2 mol) of oxydiphthalic anhydride (ODPA) was dissolved in 1000 g of NMP. 96.72 g (0.16 mol) of a diamine (HA) having the following structure and 4.97 g (0.02 mol) of 1,3-bis(3-aminopropyl)tetramethyldisiloxane (SiDA) were added thereto together with 100 g of NMP, and the mixture was reacted at 20° C. for 1 hour, and then at 50° C. for 2 hours. Next, 4.37 g (0.04 mol) of 3-aminophenol (MAP) was added as an end-capping agent together with 30 g of NMP, and the mixture was reacted at 50° C. for 2 hours. Thereafter, a solution obtained by diluting 47.66 g (0.4 mol) of N,N-dimethylformamide dimethylacetal with 50 g of NMP was added dropwise over 10 minutes. After the dropwise addition, the mixture was stirred at 50°C for 3 hours. After the stirring was completed, the solution was cooled to room temperature and then poured into 1 L of water to obtain a precipitate. The precipitate was collected by filtration, washed three times with water, and then dried in a vacuum dryer at 80°C for 20 hours to obtain a powder of polyimide precursor resin (A-15). The esterification rate by methyl groups of the resin thus obtained was 50%. The molecular weight of polyimide precursor (A-15) was measured by gel permeation chromatography (standard polystyrene equivalent) to find that the weight average molecular weight (Mw) was 25,000 and the PDI was 2.3.

The components of the polyimide precursor obtained in the synthesis example are shown in Table 1.

Example 1
The NMP solution (solid content concentration 20 wt%) of the polyimide precursor (A-1) synthesized in Synthesis Example 1 was filtered through a syringe filter (made of PTFE) with a pore size of 1.0 μm as described above to obtain a varnish. The obtained varnish was subjected to various measurements using the methods described in (1) to (7) above. The curing temperature was 180° C.
Example 2
The same procedure as in Example 1 was carried out except that the curing temperature was 200° C. However, since the varnish was the same as in Example 1, evaluation of storage stability was omitted.
Example 3
The same procedure as in Example 1 was carried out except that the curing temperature was 230° C. However, since the varnish was the same as in Example 1, evaluation of storage stability was omitted.
Example 4
The same procedure as in Example 1 was carried out except that the curing temperature was 250° C. However, since the varnish was the same as in Example 1, evaluation of storage stability was omitted.
Example 5
The same procedure as in Example 1 was repeated except that, instead of the polyimide precursor (A-1), an NMP solution (solid content concentration: 20 wt%) of the polyimide precursor (A-2) synthesized in Synthesis Example 2 was used and the curing temperature was set to 230°C.

Example 6
The same procedure as in Example 1 was repeated except that, instead of the polyimide precursor (A-1), an NMP solution (solid content concentration: 20 wt%) of the polyimide precursor (A-3) synthesized in Synthesis Example 3 was used and the curing temperature was set to 230°C.
(Example 7)
The same procedure as in Example 1 was repeated except that, instead of the polyimide precursor (A-1), an NMP solution (solid content concentration: 20 wt%) of the polyimide precursor (A-4) synthesized in Synthesis Example 4 was used and the curing temperature was set to 230°C.
(Example 8)
The same procedure as in Example 1 was repeated except that, instead of the polyimide precursor (A-1), an NMP solution (solid content concentration: 20 wt%) of the polyimide precursor (A-5) synthesized in Synthesis Example 5 was used and the curing temperature was set to 230°C.
(Example 9)
The same procedure as in Example 1 was repeated except that, instead of the polyimide precursor (A-1), an NMP solution (solid content concentration: 20 wt%) of the polyimide precursor (A-6) synthesized in Synthesis Example 6 was used and the curing temperature was set to 230°C.
(Example 10)
The same procedure as in Example 1 was repeated except that, instead of the polyimide precursor (A-1), an NMP solution (solid content concentration: 20 wt%) of the polyimide precursor (A-7) synthesized in Synthesis Example 7 was used and the curing temperature was set to 230°C.

Example 11
The same procedure as in Example 1 was repeated except that, instead of the polyimide precursor (A-1), an NMP solution (solid content concentration: 20 wt%) of the polyimide precursor (A-8) synthesized in Synthesis Example 8 was used and the curing temperature was set to 230°C.
Example 12
The same procedure as in Example 1 was repeated except that, instead of the polyimide precursor (A-1), an NMP solution (solid content concentration: 20 wt%) of the polyimide precursor (A-9) synthesized in Synthesis Example 9 was used and the curing temperature was set to 230°C.
Example 13
The same procedure as in Example 1 was repeated except that a solution (solid content concentration: 20 wt%) in which the polyimide precursor (A-10) synthesized in Synthesis Example 10 was dissolved in NMP was used instead of the polyimide precursor (A-1), and the curing temperature was set to 230°C.
(Example 14)
The same procedure as in Example 1 was repeated except that a solution (solid content concentration: 20 wt%) in which the polyimide precursor (A-11) synthesized in Synthesis Example 11 was dissolved in NMP was used instead of the polyimide precursor (A-1), and the curing temperature was set to 230°C.
(Example 15)
The same procedure as in Example 1 was repeated except that a solution (solid content concentration: 20 wt%) in which the polyimide precursor (A-12) synthesized in Synthesis Example 12 was dissolved in NMP was used instead of the polyimide precursor (A-1), and the curing temperature was set to 230°C.

(Comparative Example 1)
The same procedure as in Example 1 was repeated except that, instead of the polyimide precursor (A-1), an NMP solution (solid content concentration: 20 wt%) of the polyimide precursor (A-13) synthesized in Synthesis Example 13 was used and the curing temperature was set to 230°C.
(Comparative Example 2)
The same procedure as in Example 1 was repeated except that, instead of the polyimide precursor (A-1), an NMP solution (solid content concentration: 20 wt%) of the polyimide precursor (A-14) synthesized in Synthesis Example 14 was used and the curing temperature was set to 230°C.
(Comparative Example 3)
The same procedure as in Comparative Example 1 was repeated except that 3 parts by weight of cyclohexylamine-2-hydroxycinnamate was added as a photobase generator based on 100 parts by weight of the polyimide precursor (A-13).
(Comparative Example 4)
3.5 g of the polyimide precursor (A-15) synthesized in Synthesis Example 15, 0.5 g of a 5-naphthoquinone diazide compound (product name "TPPA-280" manufactured by Toyo Gosei Co., Ltd.), and 0.07 g of 1H-benzotriazole were diluted with NMP to a solid content concentration of 20 wt %, and filtered through a syringe filter (made of PTFE) having a pore size of 1.0 μm to obtain a varnish. The obtained varnish was subjected to various measurements using the methods described in (1) to (7) above.
The results of the examples and comparative examples are shown in Table 2.

1 Silicon wafer 2 Al pad 3 Passivation film 4 Insulation film 5 Metal (Cr, Ti, etc.) film 6 Metal wiring (Al, Cu, etc.)
7 insulating film 8 barrier metal 9 scribe line 10 solder bump 11 sealing resin 12 substrate 13 insulating film 14 insulating film 15 metal (Cr, Ti, etc.) film 16 metal wiring (Ag, Cu, etc.)
17 Metal wiring (Ag, Cu, etc.)
18 Electrode 19 Sealing resin 51 Antenna section 52 Matching circuit 53 MSL power supply line 54 Power supply point 55 Ground 56 Insulating film J Thickness of ground wiring K Thickness of antenna wiring M Length of matching circuit L Length of antenna section W Width of antenna section 601 IC chip 602 Electrode pad 603 Second via wiring 604 Planar antenna wiring 605 Second sealing resin 606 Ground 607 First via wiring 608 First sealing resin 609 Copper wiring 610 Insulating film 611 Barrier metal 612 Solder bump

Claims (13)

The present invention comprises a polyimide precursor (A) having an acid anhydride residue represented by formula (1) and an alicyclic diamine residue, and a solvent (B),
The alicyclic diamine residue is trans-1,4-cyclohexanediamine, trans-1,3-cyclohexanediamine, trans-1,2-cyclohexanediamine, cis-1,4-cyclohexanediamine, cis-1,3-cyclohexanediamine, cis-1,2-cyclohexanediamine, 1,2-bis(aminomethyl)cyclohexane, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, 4,4'-methylenebis(cyclohexylamine), 4,4'-methylenebis(2-methylcyclohexylamine). , 4,4'-isopropylidenebis(cyclohexylamine), 4,4'-isopropylidenebis(2-methylcyclohexylamine), 4,4'-hexafluoroisopropylidenebis(cyclohexylamine), 4,4'-hexafluoroisopropylidenebis(2-methylcyclohexylamine), 4,4'-bicyclohexyldiamine, 2,2'-methyl-4,4'-aminobicyclohexane, and 2,2'-trifluoromethyl-4,4'-aminobicyclohexane .

(In the formula, ^X1 and ^X2 represent either an oxygen atom, a sulfur atom, or an -NH- group; n represents an integer of 4 to 20.) The resin composition according to claim 1 , wherein X ¹ and X ² in the formula (1) are both oxygen atoms. The resin composition according to claim 1 or 2, wherein the polyimide precursor (A) has a biphenyl structure. The resin composition according to any one of claims 1 to 3, wherein the polyimide precursor (A) contains a polyamic acid ester structure. The resin composition according to any one of claims 1 to 4, wherein the polyimide precursor (A) contains 30 mol % or more and 100 mol % or less of the acid anhydride residue represented by the formula (1) relative to 100 mol % of all carboxylic acid residues in the polyimide precursor (A). A cured film obtained by curing the resin composition according to claims 1 to 5. The cured film of claim 6, which has been patterned by UV laser ablation. The cured film according to claim 6 or 7, in which the imidization rate is 97% or more and 100% or less. The cured film according to any one of claims 6 to 8, cured at a curing temperature of 200°C to 250°C. A method for producing a pattern of a cured film, comprising the steps of: applying the resin composition according to any one of claims 1 to 5 to a substrate; volatilizing the solvent (B) at 80°C or more and less than 150°C; curing the composition at 150°C or more and 250°C or less; and ablation processing using a UV laser. An electronic component having a cured film according to any one of claims 6 to 9. An antenna element comprising at least one antenna wiring and the cured film according to any one of claims 6 to 9,
an antenna element, wherein the antenna wiring includes at least one type selected from the group consisting of a meandering loop antenna, a coiled loop antenna, a meandering monopole antenna, a meandering dipole antenna, and a microstrip antenna, the area occupied by each antenna portion in the antenna wiring is 1000 ^mm2 or less, and the cured film is an insulating film that provides insulation between the ground and the antenna wiring. A semiconductor package including at least a semiconductor element, a rewiring layer, a sealing resin, and an antenna wiring,
a semiconductor package, wherein the antenna wiring includes at least one antenna selected from the group consisting of a meandering loop antenna, a coiled loop antenna, a meandering monopole antenna, a meandering dipole antenna, and a microstrip antenna, an area occupied by each antenna portion in the antenna wiring is 1000 ^mm2 or less, an insulating layer of the redistribution layer and/or the sealing resin includes the cured film according to any one of claims 6 to 9, and the sealing resin is located between a ground and the antenna wiring.

Images