JP2018154768A - Maleimide copolymer, photosensitive resin composition, semiconductor device, and electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a maleimide copolymer and a photosensitive resin composition that can form a resin film having excellent chemical resistance, a semiconductor device containing a cured product of the photosensitive resin composition, and an electronic apparatus having the semiconductor device.SOLUTION: A maleimide copolymer has: a first repeating unit represented by the formula (1); and a vinyl ether structure repeating unit that has an organic group containing a C3-30 alkylene group or an organic group containing a C3-8 cycloalkyl group. The organic group is preferably an open-chain saturated hydrocarbon or a cyclic saturated hydrocarbon.SELECTED DRAWING: None

Description

  The present invention relates to a maleimide copolymer, a photosensitive resin composition, a semiconductor device, and an electronic device.

  For semiconductor elements, resin films made of resin materials are used for applications such as protective films, interlayer insulating films, and planarization films.

  For example, Patent Document 1 proposes a photosensitive resin composition containing a polyamide resin, a photosensitive material, a phenol resin, and an adhesion assistant. Such a photosensitive resin composition is used as a protective film for protecting a semiconductor chip from external force, thermal shock, and the like by being applied to the surface of the semiconductor chip.

  On the other hand, in the manufacturing process of such a protective film, fine processing for exposing the terminals and the like is performed. Thereafter, a chemical load is applied to the protective film such as contact with the mold resin. For this reason, the protective film is required to have durability (chemical resistance) against various chemicals such as a mold resin and a solvent contained therein.

JP 2013-174843 A

  An object of the present invention includes a maleimide copolymer and a photosensitive resin composition capable of forming a resin film excellent in chemical resistance, a semiconductor device including a cured product of the photosensitive resin composition, and such a semiconductor device. To provide electronic equipment.

［式中、Ｘは、炭素数３〜３０のアルキレン基を含む有機基または炭素数３〜８のシクロアルキル基を含む有機基である。］ Such an object is achieved by the present inventions (1) to (8) below.
(1) A maleimide copolymer comprising a first repeating unit represented by the following formula (1) and a second repeating unit represented by the following formula (2).

[In formula, X is an organic group containing a C3-C30 alkylene group or a C3-C8 cycloalkyl group. ]

  (2) The maleimide copolymer according to (1), wherein the organic group is a chain saturated hydrocarbon or a cyclic saturated hydrocarbon.

(3) The maleimide copolymer according to (1), wherein the organic group further contains a hydroxyl group.
(4) The maleimide copolymer according to any one of (1) to (3), which has alkali solubility.

(5) the maleimide copolymer according to any one of (1) to (4) above,
A crosslinking agent capable of crosslinking with the maleimide copolymer;
A photosensitizer,
The photosensitive resin composition characterized by having.

  (6) The photosensitive resin composition as described in said (5) whose glass transition temperature of hardened | cured material is 250 degreeC or more.

(7) a semiconductor substrate;
A coating layer provided on the surface of the semiconductor substrate and containing a cured product of the photosensitive resin composition according to the above (5) or (6);
A semiconductor device comprising:

  (8) An electronic apparatus comprising the semiconductor device according to (7).

  According to the present invention, a maleimide copolymer and a photosensitive resin composition capable of forming a resin film excellent in chemical resistance can be obtained.

Moreover, according to this invention, the semiconductor device containing the hardened | cured material of the said photosensitive resin composition is obtained.
In addition, according to the present invention, an electronic apparatus including the semiconductor device can be obtained.

It is a longitudinal cross-sectional view which shows embodiment of the semiconductor device of this invention.

  Hereinafter, the maleimide copolymer, the photosensitive resin composition, the semiconductor device, and the electronic apparatus of the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.

<Semiconductor device>
First, prior to the description of the maleimide copolymer and the photosensitive resin composition, an embodiment of the semiconductor device of the present invention to which these are applied will be described.

  FIG. 1 is a longitudinal sectional view showing an embodiment of a semiconductor device of the present invention. In the following description, the upper side in FIG. 1 is referred to as “upper” and the lower side is referred to as “lower”.

  A semiconductor device 10 shown in FIG. 1 is a QFP (Quad Flat Package) type semiconductor package containing a semiconductor chip 20, and a die pad that supports the semiconductor chip 20 via a semiconductor chip 20 (semiconductor substrate) and an adhesive layer 60. 30, a protective film 70 (covering layer) that protects the semiconductor chip 20, leads 40 electrically connected to the semiconductor chip 20, and a mold part 50 that seals the semiconductor chip 20. As described later in detail, such a semiconductor device 10 has high reliability due to the protective action of the protective film 70.

  The die pad 30 is made of a metal substrate and has a function as a support for supporting the semiconductor chip 20.

  The die pad 30 includes a metal substrate made of various metal materials such as Cu, Fe, Ni, and alloys thereof (for example, Cu-based alloys and iron / nickel-based alloys such as Fe-42Ni), and the metal substrates. The surface of which is plated with silver or Ni—Pd, and the surface of Ni—Pd is further provided with a gold plating layer provided to improve the stability of the Pd layer. It is done.

  Moreover, the planar view shape of the die pad 30 usually corresponds to the planar view shape of the semiconductor chip 20 and is, for example, a square such as a square or a rectangle.

A plurality of leads 40 are provided radially on the outer periphery of the die pad 30.
An end portion of the lead 40 opposite to the die pad 30 protrudes (exposes) from the mold portion 50.

  Further, the exposed portion of the lead 40 from the mold portion 50 may be subjected to surface treatment such as gold plating, tin plating, solder plating, or solder coating on the surface thereof.

  The lead 40 is made of a conductive material, and for example, the same material as that of the die pad 30 described above can be used.

  The semiconductor chip 20 is fixed (fixed) to the die pad 30 via the adhesive layer 60.

  The adhesive layer 60 has a function of connecting the die pad 30 and the semiconductor chip 20 and also has a function of transmitting (dissipating) heat generated when the semiconductor chip 20 is driven to the die pad 30 side.

  The adhesive layer 60 includes, for example, a metal powder such as silver powder, aluminum powder, and nickel powder, or ceramic powder such as silica powder, alumina powder, and titania powder as an filler, an epoxy resin, an acrylic compound, Those composed of a thermosetting resin such as polyimide resin are preferably used.

The semiconductor chip 20 has an electrode pad 21 on its upper surface, and the electrode pad 21 and the lead 40 are electrically connected by a conductive wire 22. Thereby, the semiconductor chip 20 and each lead 40 are electrically connected.
The conductive wire 22 can be composed of, for example, Au wire or Al wire.

  A protective film 70 is formed on the semiconductor chip 20 so that the electrode pads 21 are exposed.

  The protective film 70 has a function of protecting the semiconductor chip 20 when the mold part 50 is cured and contracted, a thermal shock in a solder reflow process for mounting the semiconductor device 10 on a substrate or the like, and a rapid heat of the mold part 50. It has a function of protecting against expansion stress.

  In the semiconductor device 10 according to the present embodiment, the protective film 70 is formed using the photosensitive resin composition according to the present embodiment. The constituent materials of the photosensitive resin composition will be described in detail later.

  Furthermore, the die pad 30, each member provided on the upper surface side of the die pad 30, and the portion inside the lead 40 are sealed by the mold part 50. As a result, the outer end portion of the lead 40 protrudes from the mold portion 50.

  This mold part 50 can be comprised with various resin materials, such as an epoxy-type resin, for example.

<Method for Manufacturing Semiconductor Device>
Such a semiconductor device 10 can be manufactured as follows, for example.

  [1] First, a lead frame including a die pad 30 and a plurality of leads 40 is prepared.

  [2] Next, separately from this, the semiconductor chip 20 provided with the protective film 70 patterned so as to expose the electrode pads 21 is prepared.

  Such a protective film 70 can be formed on the semiconductor chip 20 as follows, for example.

  [2-1] First, the photosensitive resin composition of the present invention is prepared as a liquid material (varnish), and this liquid material is supplied using a coating method so as to cover almost the entire top surface of the semiconductor chip 20. .

Examples of the coating method include a spin coating method using a spinner, a spray coating method using a spray coater, a dipping method, a printing method, a roll coating method, and the like. Can be used in combination.
The coating amount is appropriately set according to the thickness of the protective film 70 to be formed.

  [2-2] Next, by drying the liquid material, a film containing the constituent material contained in the photosensitive resin composition is formed on the upper surface of the semiconductor chip 20.

  In addition, the drying temperature at the time of drying a liquid material becomes like this. Preferably it is about 40-150 degreeC, More preferably, it is set to about 80-130 degreeC.

  Moreover, it is preferable that the processing time at the time of drying is about 0.5 to 30 minutes, and it is more preferable that it is about 1 to 10 minutes.

  [2-3] Next, the film formed at a position corresponding to the electrode pad 21 is selectively exposed and exposed using a mask corresponding to the shape of the electrode pad 21, and then an alkaline aqueous solution or an organic solvent is used. Develop with developer. Thereby, the film is patterned into a shape in which the electrode pad 21 is exposed.

The light applied to the film formed using the photosensitive resin composition at the time of exposure / sensitivity is not particularly limited, and g-line (436 nm) and i-line (365 nm) are usually used, but i-line is particularly preferable. (365 nm) is preferably used. Thereby, the film can be surely patterned into a fine shape. Furthermore, when irradiating i line | wire at room temperature, energy amount is set to about 100-5000mJ / cm < ² >.

  Further, the aqueous alkali solution (alkaline developer) is not particularly limited. For example, in addition to organic alkali such as tetramethylammonium hydroxide, triethylamine, ethanolamine, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate Inorganic alkalis such as these can be used, and one or more of these can be used in combination. Especially, the tetramethylammonium hydroxide aqueous solution currently used by the semiconductor process is used suitably. The concentration of the tetramethylammonium hydroxide aqueous solution is set to about 0.05 to 10% by mass, preferably about 0.1 to 5% by mass. And it develops for 10 seconds-10 minutes at room temperature using this alkaline aqueous solution, and also by rinsing with a pure water, a clear positive pattern can be obtained.

  In some cases, alcohols may be added to the alkaline aqueous solution. Examples of usable alcohols include methanol, ethanol, 1-propanol, 2-propanol and the like.

The organic solvent is not particularly limited, and lactones such as γ-butyrolactone, acetone, methyl ethyl ketone (MEK), cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, ketones such as 2-heptanone, ethylene glycol, Polyhydric alcohols such as diethylene glycol, propylene glycol, dipropylene glycol, ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, dipropylene glycol monoacetate, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME) ) And the like, the polyhydric alcohols or the compounds having an ester bond. Derivatives of polyhydric alcohols such as monoalkyl ethers such as nomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether or compounds having an ether bond such as monophenyl ether [in these, propylene glycol monomethyl ether acetate ( PGMEA) and propylene glycol monomethyl ether (PGME) are preferred]; cyclic ethers such as dioxane, methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, Esters such as methyl methoxypropionate and ethyl ethoxypropionate; anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenetol, butylphenol Examples include phenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, mesitylene and other aromatic organic solvents, dimethyl sulfoxide (DMSO), and the like.
These organic solvents may be used independently and may be used as 2 or more types of mixed solvents.

  Of these, PGMEA, PGME, γ-butyrolactone or EL is preferably used.

  [2-4] Next, the patterned film is cured to obtain the protective film 70.

  In addition, the hardening process of the said film | membrane can be smoothly advanced by heating the patterned film | membrane, for example.

  The temperature for heating the film is preferably in the range of 150 to 400 ° C, more preferably in the range of 170 to 350 ° C. On the other hand, when considering the thermal effect on the semiconductor chip 20, it is preferably about 170 to 250 ° C.

  The heating time is preferably in the range of 1 to 60 minutes, and more preferably in the range of 10 to 30 minutes.

  The atmosphere for heating may be an air atmosphere, but is preferably an inert atmosphere such as nitrogen or a reduced pressure atmosphere. Thereby, hardening reaction can be advanced more reliably.

  The average film thickness of the protective film 70 is preferably about 1 to 20 μm, and more preferably about 5 to 10 μm. Thereby, the function as the protective film 70 described above can be surely exhibited.

  [3] Next, the constituent material of the adhesive layer 60 before curing is supplied onto the die pad 30 by using a commercially available discharge device such as a die bonder.

  [4] Next, the semiconductor chip 20 is placed on the die pad 30 with the surface on which the protective film 70 is provided on the die pad 30 so that the constituent material of the adhesive layer 60 before curing is interposed, and heated. To do. Thereby, the constituent material of the adhesive layer 60 before curing is cured, and the adhesive layer 60 composed of the cured product is formed. As a result, the semiconductor chip 20 is bonded onto the die pad (support) 30 via the adhesive layer 60.

  [5] Next, the conductive wire 22 is wired between the electrode pad 21 exposed from the protective film 70 and the lead 40 by wire bonding. Thereby, the electrode pad 21 and the lead 40 are electrically connected.

[6] Next, the mold part 50 is formed by, for example, transfer molding.
Thereafter, a resin-fixed tie bar is punched out from the lead frame, and a trim and foam process is performed to manufacture the semiconductor device 10.

<Protective film 70>
Next, the protective film 70 will be described.

  As described above, the protective film 70 is provided on the surface of the semiconductor chip 20 (semiconductor substrate) and contains a maleimide copolymer (an embodiment of the maleimide copolymer of the present invention) ( It is the resin film formed using the liquid material of the embodiment of the photosensitive resin composition of this invention.

≪Maleimide copolymer≫
The maleimide copolymer according to this embodiment has a first repeating unit represented by the following formula (1) and a second repeating unit represented by the following formula (2).

［式中、Ｘは、炭素数３〜３０のアルキレン基を含む有機基または炭素数３〜８のシクロアルキル基を含む有機基である。］
なお、上記「炭素数」とは、それぞれ、有機基に含まれる炭素原子の数のことをいう。

[In formula, X is an organic group containing a C3-C30 alkylene group or a C3-C8 cycloalkyl group. ]
The “carbon number” means the number of carbon atoms contained in the organic group.

  The protective film 70 (resin film) formed using the photosensitive resin composition containing such a maleimide copolymer has excellent chemical resistance. For this reason, even when the protective film 70 is subjected to a process of contacting an organic solvent or the like, the deterioration of the protective film 70 is suppressed. As a result, even after the above-described steps, the above-described function performed by the protective film 70 is maintained, and the highly reliable semiconductor device 10 can be realized.

  Moreover, moderate flexibility can be imparted to the protective film 70 by setting the carbon number of the alkylene group and the cycloalkyl group contained in the organic group within the above range. For this reason, it is possible to realize the protective film 70 having sufficient mechanical strength as a resin film and difficult to peel off following the adherend.

  If the number of carbon atoms of the alkylene group or cycloalkyl group is less than the lower limit, the molecular structure that provides flexibility is reduced, and the flexibility of the protective film 70 may be reduced. On the other hand, if the carbon number exceeds the upper limit, the flexibility tends to be excessive, and the mechanical strength of the protective film 70 may be reduced.

  X in the above formula (2) is preferably an organic group containing an alkylene group having 3 to 20 carbon atoms or an organic group containing a cycloalkyl group having 4 to 6 carbon atoms.

  Note that at least one of hydrogen atoms contained in X may be substituted with a halogen atom.

  On the other hand, having the first repeating unit mainly imparts alkali solubility to the maleimide copolymer mainly due to the phenolic hydroxyl group while imparting rigidity to the protective film 70 due to the maleimide structure. be able to. For this reason, in the photosensitive resin composition containing a maleimide-based copolymer, good developability with respect to an alkaline developer is exhibited, and a protective film 70 having an appropriate mechanical strength can be realized.

  The molar ratio of the second repeating unit in the maleimide copolymer is not particularly limited. However, when the first repeating unit is 100 mol parts, the molar ratio is preferably 10 to 900 mol parts, and more preferably 100 to 300 mol parts. Is more preferable. Thereby, the protective film 70 containing a maleimide-based copolymer can optimize the balance between flexibility and rigidity while ensuring chemical resistance. As a result, it is possible to obtain a protective film 70 that is unlikely to peel off and that is particularly reliable.

  In addition, the organic group in X in the above formula (2) is preferably a chain saturated hydrocarbon or a cyclic saturated hydrocarbon. Such a saturated hydrocarbon is composed of only carbon and hydrogen and has a low reactivity, and thus contributes to further improvement in chemical resistance of the protective film 70. Such saturated hydrocarbons also contribute effectively in optimizing the balance between the flexibility and rigidity of the protective film 70 because the carbon number is within the above range.

  The chain saturated hydrocarbon in the present embodiment is an aliphatic saturated hydrocarbon containing an alkylene group having 3 to 30 carbon atoms. For example, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl Group, tert-butyl group, pentyl group, neopentyl group, hexyl group, heptyl group, octyl group, isooctyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl Group, octadecyl group and the like.

  The cyclic saturated hydrocarbon in the present embodiment is an alicyclic saturated hydrocarbon containing a cycloalkyl group having 3 to 8 carbon atoms. For example, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclo An octyl group etc. are mentioned.

  On the other hand, the organic group in X of the above formula (2) preferably further contains a hydroxyl group. Thereby, the outstanding alkali solubility can be provided to the photosensitive resin composition containing a maleimide-type copolymer. As a result, a photosensitive resin composition having good developability and capable of processing with high resolution can be realized.

  In addition, when it contains a hydroxyl group, it is preferable that the carbon number contained in an organic group is about 3-10, and it is more preferable that it is about 4-8. The organic group is preferably a chain saturated hydrocarbon. Thereby, moderate flexibility can be imparted to the protective film 70.

≪Method for synthesizing maleimide copolymer≫
Next, an example of a method for synthesizing the maleimide copolymer according to this embodiment will be described.

(Raw material preparation process)
Examples of the monomer used as a raw material include a maleimide monomer represented by the following formula (3) and a vinyl ether monomer represented by the following formula (4).

［式中、Ｘは、炭素数３〜３０のアルキレン基を含む有機基または炭素数３〜８のシクロアルキル基を含む有機基である。］
なお、上記「炭素数」とは、それぞれ、有機基に含まれる炭素原子の数のことをいう。

[In formula, X is an organic group containing a C3-C30 alkylene group or a C3-C8 cycloalkyl group. ]
The “carbon number” means the number of carbon atoms contained in the organic group.

  Among these, examples of the maleimide monomer include 3-hydroxyphenyl maleimide and 4-hydroxyphenyl maleimide, and 4-hydroxyphenyl maleimide is particularly preferably used. A plurality of monomers can be used in combination.

  On the other hand, examples of the vinyl ether monomer include n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, tert-butyl vinyl ether, n-pentyl vinyl ether, isopentyl vinyl ether, tert-pentyl vinyl ether, n-hexyl vinyl ether, Isohexyl vinyl ether, 2-ethylbutyl vinyl ether, 2-ethylhexyl vinyl ether, n-heptyl vinyl ether, n-octyl vinyl ether, nonyl vinyl ether, decyl vinyl ether, dodecyl vinyl ether, hexadecyl vinyl ether, octadecyl vinyl ether, 2-methoxyethyl vinyl ether, 2-ethoxy Ethyl vinyl ether, 2-butoxyethyl Nyl ether, acetoxymethyl vinyl ether, 2-acetoxyethyl vinyl ether, 3-acetoxypropyl vinyl ether, 4-acetoxybutyl vinyl ether, 4-ethoxybutyl vinyl ether, 2- (2-methoxyethoxy) ethyl vinyl ether, 4-hydroxybutyl vinyl ether, 5-hydroxy Pentyl vinyl ether, 6-hydroxyhexyl vinyl ether, diethylene glycol methyl vinyl ether, diethylene glycol ethyl vinyl ether, tetraethylene glycol monovinyl ether, cyclohexyl vinyl ether, cyclohexyl methyl vinyl ether, cyclohexyl ethyl vinyl ether, 1-norbornyl vinyl ether, 2-norbornyl vinyl ether, 7- Norbornilbi Ether, benzyl vinyl ether, monofunctional vinyl etc., divinyl ethers, triethylene vinyl ethers, polyfunctional vinyl ethers such as tetra-vinyl ethers and the like, can be used singly or in combination of two or more of them.

  Of these, monofunctional vinyl ether is preferably used. This contributes to the realization of the protective film 70 in which the balance between flexibility and rigidity is optimized.

(Synthesis process)
Next, a maleimide monomer and a vinyl ether monomer are synthesized by addition polymerization. Here, as an example, a maleimide copolymer is synthesized from a maleimide monomer and a vinyl ether monomer by radical polymerization.

  For example, a maleimide monomer, a vinyl ether monomer, and a polymerization initiator are dissolved in a solvent, and heated in an inert atmosphere for a predetermined time to polymerize the maleimide monomer and the vinyl ether monomer. The heating temperature is, for example, about 50 to 80 ° C., and the heating time is, for example, about 5 to 100 hours.

Examples of the solvent include γ-butyrolactone, N-methyl-2-pyrrolidone (NMP), N, N′-dimethylacetamide (DMAc), diethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, propylene glycol monomethyl ether. , Dipropylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, methyl lactate, ethyl lactate, butyl lactate, methyl-1,3-butylene glycol acetate, 1,3-butylene glycol-3-monomethyl ether, methyl pyruvate, pyruvate Examples include ethyl, methyl-3-methoxypropionate, tetrahydrofuran, toluene, methyl ethyl ketone, and the like. It can be used as a single solvent or a mixed solvent.
Of these, γ-butyrolactone is preferably used from the viewpoint of solubility, stability, and the like.

  Examples of the polymerization initiator include 2,2′-azodiisobutyronitrile (AIBN), dimethyl 2,2′-azobis (2-methylpropionate), 1,1′-azobis (cyclohexanecarbonitrile) (ABCN). ), Hydrogen peroxide, ditertiary butyl peroxide (DTBP), benzoyl peroxide (benzoyl peroxide, BPO), and organic peroxides such as methyl ethyl ketone peroxide (MEKP). 1 type or 2 types or more are used in combination.

Although the addition amount of a polymerization initiator is not specifically limited, It is preferable that it is about 0.1-10 mol% of the sum total of a maleimide type monomer and a vinyl ether type monomer. Thereby, the molecular weight of the maleimide copolymer to be synthesized can be optimized.
A maleimide copolymer is synthesized as described above.

  The weight average molecular weight of the maleimide copolymer synthesized as described above is preferably about 5,000 to 500,000, and more preferably about 30,000 to 200,000. Thereby, the photosensitive resin composition containing such a maleimide-based copolymer has an appropriate solubility in a developer. In addition, the protective film 70 formed from such a photosensitive resin composition has particularly excellent chemical resistance, and the balance between flexibility and rigidity is optimized.

  If the weight average molecular weight of the maleimide copolymer is below the lower limit, the chemical resistance and mechanical strength of the protective film 70 may be lowered depending on the molecular structure. On the other hand, when the weight average molecular weight of the maleimide copolymer exceeds the upper limit, the solubility of the photosensitive resin composition in the developer may be lowered depending on the molecular structure, and the flexibility of the protective film 70 may be reduced. There is a risk that peeling and the like are likely to occur.

  The maleimide copolymer according to the present embodiment preferably has, for example, Mw (weight average molecular weight) / Mn (number average molecular weight) of 1.5 to 2.5. Mw / Mn is a degree of dispersion indicating the width of the molecular weight distribution. By setting Mw / Mn within the above range, for example, when forming the protective film 70 using a photosensitive resin composition containing a maleimide copolymer, pattern deformation during curing can be suppressed, and patterning can be performed. Can improve the accuracy.

  The weight average molecular weight (Mw), number average molecular weight (Mn), and molecular weight distribution (Mw / Mn) are calculated from, for example, a standard polystyrene (PS) calibration curve obtained by GPC (Gel Permeation Chromatography) measurement. Polystyrene equivalent value is used. The measurement conditions are, for example, as follows.

-Gel permeation chromatography device HLC-8320GPC manufactured by Tosoh Corporation
Column: Tosoh Corporation TSK-GEL Supermultipore HZ-M
-Detector: RI detector for liquid chromatogram-Measurement temperature: 40 ° C
・ Solvent: THF
Sample concentration: 2.0 mg / ml

  The maleimide copolymer according to this embodiment has sufficient alkali solubility, for example, as a positive photosensitive resin composition, and the alkali dissolution rate is preferably 50 nm / second or more and 2000 nm / second or less. . Thereby, the efficiency of the development process using an alkali developer can be sufficiently increased, and generation of residues after development can be sufficiently suppressed.

The alkali dissolution rate is measured as follows.
First, a maleimide copolymer is dissolved in propylene glycol monomethyl ether acetate (PGMEA) to prepare a solution having a solid content of 25% by mass.

  Next, the prepared solution is spin-coated on a silicon wafer and then dried at 100 ° C. for 6 minutes to obtain a polymer film.

  Next, this polymer film is immersed in a tetramethylammonium hydroxide aqueous solution having a concentration of 2.38% by mass and left to stand for 30 seconds.

  Next, the polymer film is taken out and rinsed with pure water, and the presence or absence of a polymer film residue is visually confirmed. Then, the alkali dissolution rate is calculated by measuring the time required until the polymer film disappears.

  Further, the synthesized maleimide copolymer may contain low molecular weight components such as monomers and oligomers that have not been polymerized. Examples of such a low molecular weight component include the monomers of the above formulas (3) and (4).

  In that case, the content of the low molecular weight component is preferably appropriately controlled so that the peak area at a molecular weight of 1000 or less is 2% or less in the molecular weight distribution curve obtained by GPC. Thereby, when forming the protective film 70 using the photosensitive resin composition containing a maleimide-type copolymer, for example, the deformation | transformation of the pattern at the time of hardening can be suppressed and the precision of patterning can be improved.

  In the plurality of first repeating units included, the bonding positions of the hydroxyl groups with respect to the benzene ring of formula (1) are preferably the same as each other, but may be different from each other.

  In the plurality of second repeating units included, X in the formula (2) is preferably the same organic group as each other, but may be different from each other.

  The maleimide copolymer according to the present embodiment may be an alternating copolymer in which the first repeating units and the second repeating units are alternately arranged, or a random copolymer in which the first repeating units are randomly arranged. It may be a block copolymer formed by arranging each block.

  Among these, from the viewpoint of stabilizing the characteristics of the maleimide copolymer, an alternating copolymer is preferable. That is, the maleimide copolymer according to this embodiment preferably has a repeating unit represented by the following formula (5).

［式中、Ｘは、炭素数３〜３０のアルキレン基を含む有機基または炭素数３〜８のシクロアルキル基を含む有機基である。また、ｎは１０〜３０００の整数である。］
なお、上記「炭素数」とは、それぞれ、有機基に含まれる炭素原子の数のことをいう。

[In formula, X is an organic group containing a C3-C30 alkylene group or a C3-C8 cycloalkyl group. N is an integer of 10 to 3000. ]
The “carbon number” means the number of carbon atoms contained in the organic group.

  In the plurality of repeating units contained, X in the formula (5) is preferably the same organic group as each other, but may be different from each other.

  Furthermore, the maleimide copolymer according to the present embodiment has a repeating unit represented by the following formula (6) from the viewpoint of making the above-described functions and effects of the maleimide copolymer more remarkable. Is more preferable.

［式中、Ｘは、炭素数３〜３０のアルキレン基を含む有機基または炭素数３〜８のシクロアルキル基を含む有機基である。また、ｎは１０〜３０００の整数である。］
なお、上記「炭素数」とは、それぞれ、有機基に含まれる炭素原子の数のことをいう。

[In formula, X is an organic group containing a C3-C30 alkylene group or a C3-C8 cycloalkyl group. N is an integer of 10 to 3000. ]
The “carbon number” means the number of carbon atoms contained in the organic group.

After that, the synthesized maleimide copolymer may be washed.
This washing is performed, for example, by dropping a solution containing a maleimide copolymer into a mixed solvent of water and an organic solvent (for example, acetone), stirring, and allowing to stand, and then collecting the precipitate. .

  Thereafter, the collected precipitate is dried to obtain a solid maleimide copolymer.

≪Photosensitive resin composition≫
The photosensitive resin composition according to the present embodiment includes the maleimide copolymer according to the present embodiment, a crosslinking agent capable of crosslinking with the maleimide copolymer, and a photosensitive agent. Such a photosensitive resin composition makes it possible to form a resin film such as the protective film 70 having excellent chemical resistance by the action and effect of the maleimide copolymer described above.

(Maleimide copolymer)
Although the photosensitive resin composition which concerns on this embodiment has the maleimide-type copolymer mentioned above, when the total solid content of the photosensitive resin composition is 100 mass parts, it is 20-20. The amount is preferably 90 parts by mass, and more preferably 30 to 80 parts by mass. Thereby, the photosensitive resin composition can fully exhibit the characteristics of the maleimide copolymer described above.

(Crosslinking agent)
The photosensitive resin composition according to the present embodiment has a crosslinking agent capable of crosslinking with the maleimide copolymer. Thereby, sclerosis | hardenability can be improved and the mechanical strength of a cured film like the protective film 70 can be raised.

  Examples of the crosslinking agent include melamine type, substituted urea type, or polymer type thereof.

  Further, as the cross-linking agent, those having at least two cross-linking substituents such as a methylol group and an alkoxymethyl group are preferably used, and a nitrogen-containing compound having 2 to 4 nitrogen atoms substituted with the cross-linking substituents Is more preferably used.

  Examples of such nitrogen-containing compounds include hexamethoxymethyl melamine (trade names: MX-30HM, MX-390, MX-100LM, manufactured by Sanwa Chemical Co., Ltd.), tetramethoxymethyl benzoguanamine, 1, 3, 4 , 6-Tetrakis (methoxymethyl) glycoluril (trade name: MX-270, manufactured by Sanwa Chemical Co., Ltd.), 1,3,4,6-tetrakis (butoxymethyl) glycoluril, 1,3,4,6 -Tetrakis (hydroxymethyl) glycoluril, 1,3-bis (hydroxymethyl) urea, 1,1,3,3-tetrakis (butoxymethyl) urea, 1,1,3,3-tetrakis (methoxymethyl) urea, etc. These may be used, and one or more of these may be used in combination.

  Other aromatic compounds substituted with a methylol group or a methoxymethyl group include, for example, 1-hydroxybenzene-2,4,6-trimethanol, 3,3 ′, 5,5′-tetrakis (hydroxymethyl) -4 , 4′-dihydroxybiphenyl, 5,5 ′-[2,2,2-trifluoro-1- (trifluoromethyl) ethylidene] bis [2-hydroxy-1,3-benzenedimethanol], 2,2- Dimethoxymethyl-4-t-butylphenol, 3,3 ′, 5,5′-tetramethoxymethyl-4,4′-dihydroxybiphenyl, bis (2-hydroxy-3-hydroxymethyl-5-methylphenyl) methane, bis (4-Hydroxy-3-hydroxymethyl-5-methylphenyl) methane, 5,5 ′-(1-methylethylidene) bis (2- Dorokishi 1,3 benzenedimethanol), whether employed singly or in combination of two or more of them.

  Although the content rate of a crosslinking agent is not specifically limited, It is preferable that it is about 1-80 mass parts with respect to 100 mass parts of maleimide-type copolymers, and it is more preferable that it is about 10-60 mass parts. If the content of the crosslinking agent is lower than the lower limit value or higher than the upper limit value, the chemical resistance of the cured film such as the protective film 70 may be lowered.

(Photosensitive agent)
The photosensitive resin composition according to the present embodiment has a photosensitive agent. The patterning method can be selected from a positive type and a negative type.

  In the case of the positive type, the film obtained by drying the photosensitive resin composition is selectively irradiated with light, so that the solubility of the film located in the light irradiation region in the alkaline aqueous solution can be reduced. Compared to the solubility of the film located in the non-irradiated region in the alkaline aqueous solution, the film can be improved. Therefore, alkali solubility can be imparted to the photosensitive resin composition, and a positive photosensitive resin composition can be provided.

  In the case of the negative type, the film located in the light irradiation region is insoluble in the organic solvent by applying a heating process after selectively irradiating the film obtained by drying the photosensitive resin composition. Thus, the film located in the non-irradiated region remains soluble in the organic solvent. Therefore, the organic resin insolubility can be imparted to the photosensitive resin composition, and a negative photosensitive resin composition can be provided.

  As the photosensitive agent, in the case of a positive photosensitive resin composition, a photoacid generator that generates an acid by absorbing light energy can be used.

  Specifically, diazoquinone compound; diaryl iodonium salt; 2-nitrobenzyl ester compound; N-iminosulfonate compound; imidosulfonate compound; 2,6-bis (trichloromethyl) -1,3,5-triazine compound; dihydropyridine compound Etc.

  Among these compounds, photosensitive diazoquinone compounds are preferably used. Since such a compound is most excellent in sensitivity and resolution in the wavelength range of actinic radiation mainly used for exposure, the protective film 70 can be formed with excellent patterning accuracy.

  Examples of the photosensitive diazoquinone compound include esters of a phenol compound and 1,2-naphthoquinone-2-diazide-5-sulfonic acid or 1,2-naphthoquinone-2-diazide-4-sulfonic acid. These may be used alone or in combination of two or more.

  In addition, as a specific structure of these compounds, Formula (B10)-Formula (B16) described in Unexamined-Japanese-Patent No. 2013-174843 is mentioned, for example.

  On the other hand, in the case of a negative photosensitive resin composition, a photoacid generator is used as a photosensitizer, and further a crosslinker that crosslinks a polymer by the action of an acid.

  Specifically, any acid may be used as long as it generates an acid by absorbing light energy. For example, triarylsulfonium salt, triphenylsulfonium trifluoromethanesulfonate, tris (4-t-butylphenyl) sulfonium-trifluoromethane. Sulfonium salts such as sulfonate; diazonium salts such as p-nitrophenyldiazonium hexafluorophosphate; ammonium salts; phosphonium salts; iodonium salts such as diphenyliodonium trifluoromethanesulfonate, (triccumyl) iodonium-tetrakis (pentafluorophenyl) borate; quinonediazides , Diazomethanes such as bis (phenylsulfonyl) diazomethane; 1-phenyl-1- (4-methylphenyl) sulfonyloxy Sulfonic acid esters such as -1-benzoylmethane and N-hydroxynaphthalimide-trifluoromethanesulfonate; disulfones such as diphenyldisulfone; tris (2,4,6-trichloromethyl) -s-triazine, 2- (3 And compounds such as triazines such as 4-methylenedioxyphenyl) -4,6-bis (trichloromethyl) -s-triazine. These photoacid generators can be used alone or in combination.

  Although the content rate of a photosensitive agent is not specifically limited, It is preferable that it is about 1-50 mass parts with respect to 100 mass parts of maleimide-type copolymers, It is more preferable that it is about 5-40 mass parts, 8- More preferably, it is about 30 parts by mass. Thereby, the difference in alkali solubility between the light irradiation region (exposure portion) and the light non-irradiation region (non-exposure portion) can be surely expressed.

  The photosensitive resin composition which concerns on this embodiment may have the acid generator which generates an acid with heat other than a photosensitive agent as needed. By including such an acid generator, the crosslinking reaction between the maleimide copolymer and the crosslinking agent can be promoted by heating the photosensitive resin composition.

  Although the content rate of an acid generator is not specifically limited, It is preferable that it is 3 mass parts or less with respect to 100 mass parts of crosslinking agents.

  Examples of thermal acid generators that generate acid by heat include SI-45L, SI-60L, SI-80L, SI-100L, SI-110L, SI-150L, SI-200 (Sanshin Chemical Industry Co., Ltd.) Aromatic sulfonium salts such as

  In addition, when the total solid content of a resin composition is 100 mass parts, it is preferable that the content rate of an acid generator is 0.1-5 mass parts.

(Surfactant)
The photosensitive resin composition according to this embodiment may have a surfactant as necessary.

  As the surfactant, for example, one having a crosslinkable group is used. Examples of the crosslinkable group contained in the surfactant include those that crosslink with a maleimide copolymer or a crosslinking agent, or that crosslink with a surfactant alone. In particular, the crosslinkable group is preferably one that causes a crosslinking reaction by light or heat, and examples thereof include a (meth) acryloyl group and a vinyl group. In this case, it is possible to perform crosslinking more efficiently by further including a radical polymerization initiator such as azobisisobutyronitrile (AIBN), benzoyl peroxide (BPO) in the photosensitive resin composition. is there.

  Thus, the coating property of the photosensitive resin composition can be improved by adding a surfactant having a crosslinkable group to the photosensitive resin composition. Furthermore, by using a surfactant having a crosslinkable group, the surfactant can cause a crosslinking reaction to improve the chemical resistance of the cured film of the photosensitive resin composition.

  The surfactant having a crosslinkable group is preferably a compound containing a fluorine group (for example, a fluorinated alkyl group) or a silanol group, or a compound having a siloxane bond as a main skeleton. Such a surfactant is collected on the surface of the coating film of the photosensitive resin composition by having a fluorine group or a silanol group or having a siloxane bond as a main skeleton. And since it will carry out a crosslinking reaction on the surface of the film | membrane of the photosensitive resin composition, the chemical resistance of the cured film of the photosensitive resin composition can be improved more reliably. Such an effect can be particularly prominent by using a surfactant having a fluorine group.

The surfactant having a crosslinkable group may be any of a nonionic surfactant, a cationic surfactant, and an anionic surfactant, but is a nonionic surfactant from the viewpoint of the stability of the photosensitive resin composition. It is preferable. For example, the surfactant having a crosslinkable group is a nonionic surfactant, and preferably has a polyoxyalkylene chain as a hydrophilic group. Examples of the polyoxyalkylene chain may include those represented by (OR) x, wherein R is an alkylene chain having 2 to 4 carbon atoms, and —CH ₂ CH ₂ —, —CH ₂ CH ₂ CH ₂ — , —CH (CH ₃ ) CH ₂ —, —CH ₂ CH ₂ CH ₂ CH ₂ —, or —CH (CH ₃ ) CH (CH ₃ ) — is preferable. Note that x is a positive integer, preferably an integer of 2 to 50, and more preferably an integer of 3 to 30.

  Moreover, you may make it use together the surfactant which does not have a crosslinkable group with the surfactant which has a crosslinkable group. Thereby, smoothing of a cured film can be aimed at and generation | occurrence | production of the crack of a cured film can be suppressed.

  The surfactant having no crosslinkable group may be any of a nonionic surfactant, a cationic surfactant, and an anionic surfactant. From the viewpoint of the stability of the photosensitive resin composition, the nonionic surfactant is used. It is preferable that The surfactant having no crosslinkable group is preferably a compound containing a fluorine group or a silanol group or a compound having a siloxane bond as a main skeleton from the viewpoint of smoothing the film surface. Such a surfactant having a fluorine group or a silanol group or having a siloxane bond as a main skeleton has a high surface tension reducing ability, so that the film surface can be smoothed.

  As mentioned above, although it explained in full detail about each component of the photosensitive resin composition, a photosensitive resin composition is a base generator, a crosslinking catalyst, antioxidant, a filler, a sensitizer, an adhesive improvement agent etc. as needed. The additive may be included.

  Moreover, the photosensitive resin composition may contain the solvent which melt | dissolves or disperse | distributes the component mentioned above uniformly. Examples of such solvents include propylene glycol methyl ether acetate, dimethylformamide, toluene, benzene, xylene, methyl ethyl ketone, tetrahydrofuran, ethyl cellosolve, ethyl cellosolve acetate, dioxane, cyclohexanone, ethyl acetate, N-methyl-pyrrolidinone, One or a combination of two or more of these is used.

<< Hardened product of photosensitive resin composition >>
The photosensitive resin composition which concerns on this embodiment hardens | cures through the hardening process which is illustrated below, for example, and produces | generates hardened | cured material. This cured product preferably has the following physical properties.

(Glass transition temperature and thermal expansion coefficient)
First, the photosensitive resin composition varnished with propylene glycol methyl ether acetate (PGMEA) is passed through a filter having a pore diameter of 0.5 μm.

  Next, the photosensitive resin composition passed through the filter is applied to a silicon wafer or the like, and the obtained coating film is dried by heating at 100 ° C. for 6 minutes.

  Next, the temperature in the clean oven is maintained at 30 ° C., and a silicon wafer provided with a dried coating film is placed inside.

Next, the temperature is raised to 200 ° C. at a rate of 5 ° C. per minute, and then held for 60 minutes, and then lowered to 80 ° C. at a rate of 5 ° C. per minute.
A cured film having a thickness of 10 μm is obtained as described above.
A test piece having a width of 5 mm and a length of 10 mm or more is cut out from the cured film.

  Next, the glass transition temperature Tg and linear expansion of this test piece were measured using a thermomechanical analysis (TMA) apparatus under the conditions of a starting temperature of 30 ° C., a measurement temperature range of 30 to 400 ° C., and a heating rate of 5 ° C./min. The coefficient CTE is measured.

  The cured product of the photosensitive resin composition according to this embodiment preferably has a glass transition temperature Tg of 250 ° C or higher, more preferably 280 ° C or higher. The cured product of such a photosensitive resin composition has a sufficiently high mechanical strength even at high temperatures. For this reason, for example, even when it is subjected to a solder reflow process or the like, the protective film 70 that does not easily lose its function is obtained.

  Further, the cured product of the photosensitive resin composition according to this embodiment preferably has a thermal expansion coefficient of −50 to 50 ppm / ° C., and more preferably −30 to 30 ppm / ° C. Since such a cured product of the photosensitive resin composition has a small difference in thermal expansion from a semiconductor material such as silicon, for example, warpage of the semiconductor chip 20 and defects due to thermal stress can be suppressed.

(Tensile strength, tensile modulus and tensile elongation)
First, a cured film is obtained in the same manner as the evaluation of the glass transition temperature.
A test piece having a width of 10 mm and a length of 60 mm or more is cut out from the cured film.

  Next, the test piece is subjected to a tensile test using a tensile tester. The test conditions are a tensile speed of 0.05 mm / min, a temperature of 23 ° C., and a relative humidity of 55%.

  And a tensile strength, a tensile elasticity modulus, and a tensile elongation rate are computed from the result of a tension test. In addition, about a measurement result, it is set as the average value of the measured value obtained from five or more test pieces, respectively.

  The cured product of the photosensitive resin composition according to this embodiment preferably has a tensile strength of 20 MPa or more, and more preferably 30 to 300 MPa. Thereby, the protective film 70 having sufficient mechanical strength and excellent durability can be obtained.

  Moreover, it is preferable that the cured | curing material of the photosensitive resin composition which concerns on this embodiment has a tensile elasticity modulus of 1 GPa or more, and it is more preferable that it is 2-5 GPa. Thereby, the protective film 70 having sufficient mechanical strength and excellent durability can be obtained.

  Further, the cured product of the photosensitive resin composition according to the present embodiment preferably has a tensile elongation of 1% or more, more preferably 5% or more, and further preferably 20 to 50%. . Thereby, the hardened | cured material like the protective film 70 excellent in shape followability is obtained. As a result, the protective film 70 becomes more difficult to peel off.

  The physical properties as described above are the same as those described above for the cured product in which the maximum temperature during curing is reduced from 200 ° C to 180 ° C. Even when cured at such a relatively low temperature, the photosensitive resin composition according to the present embodiment can produce a cured product having excellent mechanical properties. For this reason, the thermal load applied to the semiconductor chip 20 and the like at the time of curing can be further reduced, which can contribute to the improvement of the reliability of the semiconductor chip 20. Moreover, since the thermal expansion coefficient is reduced along with the suppression of the thermal load, the occurrence of defects due to stress concentration is also suppressed.

(chemical resistance)
First, the photosensitive resin composition varnished with propylene glycol methyl ether acetate is passed through a filter having a pore diameter of 0.5 μm.

Next, the photosensitive resin composition passed through the filter is applied to a silicon wafer or the like, and the obtained coating film is dried.
Drying is performed by heating on a hot plate at 100 ° C. for 136 seconds.

Next, the dried coating film is immersed in an alkali developer (tetramethylammonium hydroxide aqueous solution having a concentration of 0.5% by mass) and left to stand for 90 seconds.
Next, the coating film is taken out and rinsed with pure water.

Next, ultraviolet rays are exposed at 300 mJ / cm ² and then heated in an oven at 230 ° C. for 60 minutes.
The film thickness of the coating film after heating is measured, and this is defined as t1.

  Next, the heated coating film is immersed in a chemical and left to stand for a predetermined time. Examples of chemicals include N-methylpyrrolidone (NMP), dimethyl sulfoxide (DMSO), propylene glycol monomethyl ether (PGME), propylene glycol monomethyl ether acetate (PGMEA), tetramethylammonium hydro hydride having a concentration of 2.38% by mass Examples thereof include an aqueous oxide (TMAH) solution.

Next, the coating film is taken out, the film thickness is measured, and this is defined as t2.
And (t1-t2) / t1 * 100 is calculated and this is made into film thickness change rate (%).

  When the cured product of the photosensitive resin composition according to this embodiment is brought into contact with N-methylpyrrolidone (NMP) at 60 ° C. for 10 minutes, the rate of change in film thickness is preferably 5% or less, and preferably 3% or less. It is more preferable that Thereby, even when the protective film 70 is subjected to the step of being immersed in N-methylpyrrolidone, the film thickness is hardly reduced. For this reason, the protective film 70 which can maintain a function even after being subjected to such a process is obtained.

  The film thickness change rate when the cured product of the photosensitive resin composition according to the present embodiment is brought into contact with dimethyl sulfoxide (DMSO) at 60 ° C. for 10 minutes is preferably 5% or less, and preferably 3% or less. It is more preferable that Thereby, even when the protective film 70 is subjected to the step of being immersed in dimethyl sulfoxide, the film thickness is hardly reduced. For this reason, the protective film 70 which can maintain a function even after being subjected to such a process is obtained.

  Further, the rate of change in film thickness when the cured product of the photosensitive resin composition according to this embodiment is brought into contact with propylene glycol monomethyl ether (PGME) at 25 ° C. for 30 minutes is preferably 5% or less. % Or less is more preferable. Thereby, even when the protective film 70 is subjected to a step of being immersed in propylene glycol monomethyl ether, the film thickness is hardly reduced. For this reason, the protective film 70 which can maintain a function even after being subjected to such a process is obtained.

  The rate of change in film thickness when the cured product of the photosensitive resin composition according to this embodiment is brought into contact with propylene glycol monomethyl ether acetate (PGMEA) at 25 ° C. for 30 minutes is preferably 5% or less, More preferably, it is 3% or less. Thereby, even when the protective film 70 is subjected to the step of being immersed in propylene glycol monomethyl ether acetate, the film thickness is hardly reduced. For this reason, the protective film 70 which can maintain a function even after being subjected to such a process is obtained.

  In addition, when the cured product of the photosensitive resin composition according to the present embodiment is brought into contact with an aqueous tetramethylammonium hydroxide (TMAH) solution having a concentration of 2.38% by mass at 25 ° C. for 15 minutes, the film thickness change rate is 5 % Or less is preferable, and 3% or less is more preferable. Thereby, even when the protective film 70 is subjected to the step of being immersed in tetramethylammonium hydroxide, the film thickness is hardly reduced. For this reason, the protective film 70 which can maintain a function even after being subjected to such a process is obtained.

  In addition to the protective film 70 (passivation film) described above, the cured product of the photosensitive resin composition according to the present embodiment includes, for example, a semiconductor buffer coat, a rewiring layer, an α-ray prevention film, an interlayer insulating film, a photo It can be applied to photosensitive coating materials (coating layers) for various semiconductors such as resists.

  Among these, permanent films such as a semiconductor buffer coat, a rewiring layer, an α-ray prevention film, and an interlayer insulating film are required to have durability and mechanical strength for protecting the semiconductor chip 20. From this point of view, the photosensitive coating material including the cured product of the photosensitive resin composition according to the present embodiment can protect the semiconductor chip 20 over a long period of time when used as a permanent film, and is reliable. This contributes to the realization of a semiconductor device 10 having a high level.

<Electronic equipment>
The electronic apparatus according to the present embodiment includes the semiconductor device according to the present embodiment described above.

  Since such a semiconductor device includes a protective film having excellent chemical resistance, it is highly reliable. For this reason, high reliability is also provided to the electronic apparatus according to the present embodiment.

  The electronic device according to the present embodiment is not particularly limited as long as it includes such a semiconductor device. For example, the electronic device is a communication device such as a mobile phone, a smartphone, a tablet terminal, a personal computer, a server, or a router. Examples of such devices include in-vehicle devices such as devices, vehicle control computers, and car navigation systems.

  As mentioned above, although this invention was demonstrated based on embodiment of illustration, this invention is not limited to these.

  For example, the maleimide copolymer, photosensitive resin composition, semiconductor device, and electronic device of the present invention may be those obtained by adding arbitrary elements to the above embodiment.

  Moreover, the photosensitive resin composition is applicable to, for example, MEMS (Micro Electro Mechanical Systems) and various sensor structure forming materials in addition to semiconductor devices.

Next, specific examples of the present invention will be described.
1. Synthesis of maleimide copolymer (Synthesis Example 1)
[1] First, in a flask equipped with a condenser and a stirrer, 4-hydroxyphenylmaleimide (Seiko Chemical Co., Ltd.) as a maleimide monomer, butyl vinyl ether (Tokyo Chemical Industry Co., Ltd.) as a vinyl ether monomer, and polymerization initiation 2,2′-Azodiisobutyronitrile (Tokyo Chemical Industry Co., Ltd.) was dissolved in γ-butyrolactone (Tokyo Chemical Industry Co., Ltd.) as a solvent and stirred. In addition, the compounding ratio of each raw material is as shown in Table 1.

  [2] Next, after the atmosphere in the flask was replaced with nitrogen, the temperature of the solution was raised to 70 ° C. while stirring, and then maintained for 6 hours. Thereby, a reaction solution was obtained.

  [3] Next, the obtained reaction solution was dropped into an aqueous acetone solution over 5 minutes while stirring. The aqueous acetone solution was prepared so as to have a mass ratio of water / acetone = 9/1.

  [4] Next, the acetone aqueous solution to which the reaction solution was dropped was allowed to stand for 30 minutes, and then the supernatant was removed and the precipitate was collected. And the collect | recovered deposit was heated up to 60 degreeC under vacuum pressure reduction, and was then dried over 48 hours. As a result, a polymer (maleimide copolymer) was obtained.

(Synthesis Examples 2-9)
A polymer was obtained in the same manner as in Synthesis Example 1 except that the raw materials and the blending ratio thereof were changed as shown in Table 1.

(Comparative Synthesis Examples 1 and 2)
Except for changing the raw materials and the blending ratio thereof as shown in Table 1, attempts were made to obtain a polymer in the same manner as in Synthesis Example 1, but the polymer could not be precipitated.

  Although the methyl vinyl ether used in Comparative Synthesis Example 1 is a vinyl ether monomer, the organic group corresponding to X in the formula (2) is a methyl group.

  Moreover, although the ethyl vinyl ether used in Comparative Synthesis Example 2 is a vinyl ether monomer, the organic group corresponding to X in Formula (2) described above is an ethyl group.

(Comparative Synthesis Example 3)
[1] First, in a flask equipped with a condenser and a stirrer, 3,5-diaminobenzoic acid (Tokyo Kasei Kogyo Co., Ltd.) as diamine and 4,4′-oxydiphthalic anhydride (Tokyo Kasei Kogyo) as acid anhydride Were dissolved in γ-butyrolactone as a solvent and stirred.

  [2] Next, after the atmosphere in the flask was replaced with nitrogen, the temperature of the solution was increased to 35 ° C. while stirring, and then maintained for 1 hour. Thereby, a reaction solution was obtained.

  [3] Next, 20 g of toluene was added to the resulting reaction solution, and toluene and water were distilled off while heating at 180 ° C. to obtain a polymer (polyamic acid).

2. 2.1 Evaluation of Maleimide Copolymer 2.1 Evaluation of Polymerizability The polymer obtained in each synthesis example and comparative synthesis example 3 is obtained from a standard polystyrene (PS) calibration curve obtained by GPC (Gel Permeation Chromatography) measurement. A molecular weight distribution curve in terms of polystyrene was determined.

  Then, the polymerizability of the polymer was evaluated according to what percentage of the peak area at a molecular weight of 1000 or less. In addition, this evaluation was performed in light of the following evaluation criteria for the obtained peak area ratio.

<Evaluation criteria for polymerizability>
○: The ratio of the peak area is 2% or less. Δ: The ratio of the peak area is more than 2% and 40% or less. X: The ratio of the peak area is more than 40%.

2.2 Evaluation of molecular weight About the polymer obtained in each synthesis example and comparative synthesis example 3, the weight average molecular weight was calculated from the molecular weight distribution curve of polystyrene conversion value obtained from the calibration curve of standard polystyrene (PS) obtained by GPC measurement. Asked.
The measurement results are shown in Table 1.

2.3 Evaluation of degree of dispersion For the polymers obtained in each synthesis example and comparative synthesis example 3, the weight average molecular weight was determined from the molecular weight distribution curve in terms of polystyrene calculated from the standard polystyrene (PS) calibration curve obtained by GPC measurement. Mw and number average molecular weight Mn were determined.

Next, the degree of dispersion defined by Mw / Mn was calculated.
The calculation results are shown in Table 1.

2.4 Evaluation of Alkali Solubility The polymer obtained in each Synthesis Example and Comparative Synthesis Example 3 was dissolved in propylene glycol monomethyl ether acetate (PGMEA) to prepare a solution having a solid content of 25% by mass.
Next, the prepared solution was passed through a filter having a pore size of 0.5 μm.

  Next, the solution passed through the filter was spin-coated on a silicon wafer, and then dried at 100 ° C. for 6 minutes to obtain a polymer film.

  Next, the obtained polymer film was immersed in an aqueous tetramethylammonium hydroxide solution having a concentration of 2.38% by mass and allowed to stand for 30 seconds.

  Next, the polymer film was taken out and rinsed with pure water, and the presence or absence of a polymer film residue was visually confirmed. The alkali dissolution rate was calculated by measuring the time required until the polymer film disappeared.

  And the alkali solubility was evaluated in light of the calculated alkali dissolution rate against the following evaluation criteria.

<Evaluation criteria for alkali solubility>
○: Alkali dissolution rate is 50 nm / second or more and 2000 nm / second or less Δ: Alkali dissolution rate is less than 50 nm / second or more than 2000 nm / second ×: Not dissolved at all Evaluation results are shown in Table 1.

  As is clear from Table 1, it was confirmed that the polymers obtained in the respective synthesis examples had good polymerizability and also had alkali solubility.

  On the other hand, in Comparative Synthesis Examples 1 and 2, the polymer could not be obtained due to the low polymerizability of the monomer.

3. Preparation of photosensitive resin composition (Example 1)
As a polymer of Synthesis Example 1, 1,3,4,6-tetrakis (methoxymethyl) glycoluril (trade name: MX-270, manufactured by Sanwa Chemical Co., Ltd.) as a crosslinking agent, and as a photosensitizer (photoacid generator) A compound represented by the following formula (17) and RS-75 manufactured by DIC Corporation as a surfactant are dissolved in propylene glycol monomethyl ether acetate (PGMEA) as a solvent, and a filter having a pore size of 0.5 μm is prepared. I let it pass. Thereby, a photosensitive resin composition was obtained. In addition, the blending ratio of each raw material is as shown in Table 2.

［式中、Ｑは、水素原子または下記式（１８）である。］

[In formula, Q is a hydrogen atom or following formula (18). ]

(Examples 2 to 10)
A photosensitive resin composition was obtained in the same manner as in Example 1 except that the raw materials and the blending ratio thereof were changed as shown in Table 2.

  “CPI-200K” in Table 2 is a photosensitizer CPI-200K manufactured by San Apro Co., Ltd.

(Comparative Examples 1-4)
A photosensitive resin composition was obtained in the same manner as in Example 1 except that the raw materials and the blending ratio thereof were changed as shown in Table 2.

4). 4. Evaluation of photosensitive resin composition 4.1 Evaluation of patterning property 4.1.1 Positive patterning property [1] First, the photosensitive resin composition of each example and each comparative example was spin-coated on a silicon wafer. And dried at 120 ° C. for 3 minutes to obtain a dry film having a film thickness of 9.0 to 10.0 μm.

  [2] Next, irradiation was performed by changing the exposure amount using an i-line stepper (Nikon Corporation NSR-4425i) through a positive pattern mask.

  [3] Next, using an aqueous solution of tetramethylammonium hydroxide (TMAH) having a concentration of 2.38% by mass at 25 ° C. as a developer, the exposed portion is dissolved and removed by performing paddle development, and then rinsed with pure water. did. The film thickness after rinsing was 7.0 to 8.0 μm.

  [4] Next, whether or not patterning could be performed was visually confirmed, and positive patterning property was evaluated in light of the following evaluation criteria.

<Positive patterning evaluation criteria>
◯: A pattern could be obtained by dissolving the exposed area. ×: A pattern could not be obtained due to total dissolution or insolubility.

4.1.2 Negative patterning properties [1] First, the photosensitive resin compositions of the respective examples and comparative examples were spin-coated on a silicon wafer and then dried at 120 ° C. for 3 minutes to obtain a film thickness of 9.0. A dry film of ˜10.0 μm was obtained.

  [2] Next, irradiation was performed by changing the exposure amount using an i-line stepper (NSR-4425i, manufactured by Nikon Corporation) through a negative pattern mask. Thereafter, heating was performed at 100 ° C. for 3 minutes.

  [3] Next, using propylene glycol monomethyl ether acetate (PGMEA) at 25 ° C. as a developing solution, paddle development was performed to dissolve and remove the unexposed portion, followed by rinsing with isopropyl alcohol (IPA). The film thickness after rinsing was 9.0 to 10.0 μm.

  [4] Next, it was visually confirmed whether or not patterning was possible, and negative patterning property was evaluated in light of the following evaluation criteria.

<Evaluation criteria for negative patterning>
○: A pattern could be obtained by dissolving the unexposed area. ×: A pattern could not be obtained due to total dissolution or insolubility.

4.2 Evaluation of low-temperature curability [1] First, the photosensitive resin compositions of Examples and Comparative Examples were spin-coated on a silicon wafer and then dried at 100 ° C. for 6 minutes to obtain a dried film.

  [2] Next, the temperature in the clean oven was maintained at 30 ° C., and a silicon wafer provided with a dry film was placed therein.

  [3] Next, the temperature in the clean oven was raised to 200 ° C. at a rate of 5 ° C. per minute, held for 60 minutes, and then lowered to 80 ° C. at a rate of 5 ° C. per minute. As described above, a cured film having a thickness of 10 μm was obtained.

  [4] Next, it was visually confirmed whether or not a cured film could be produced, and low temperature curability at 200 ° C. was evaluated in light of the following evaluation criteria.

<Evaluation criteria for low-temperature curability>
○: A cured film could be produced. ×: A cured film could not be produced. Table 2 shows the evaluation results.

4.3 Evaluation of glass transition temperature The glass transition temperature was measured about the cured film of the photosensitive resin composition of each Example and each comparative example.
The measurement results are shown in Table 2.

4.4 Evaluation of Tensile Strength, Tensile Elastic Modulus, and Tensile Elongation Tensile strength, tensile elastic modulus, and tensile elongation were measured for the cured films of the photosensitive resin compositions of Examples and Comparative Examples.
The measurement results are shown in Table 2.

4.5 Evaluation of chemical resistance Chemical resistance was measured for the cured films of the photosensitive resin compositions of Examples and Comparative Examples.

In addition, the chemical | medical agent used for evaluation is as follows.
・ N-methylpyrrolidone (NMP)
・ Dimethyl sulfoxide (DMSO)
・ Propylene glycol monomethyl ether (PGME)
・ Propylene glycol monomethyl ether acetate (PGMEA)
-Tetramethylammonium hydroxide (TMAH) 2.38 mass% aqueous solution Evaluation result is shown in Table 2.

  As is apparent from Table 2, it was confirmed that the photosensitive resin compositions of the respective examples had curability at a relatively low temperature.

  Also, the cured product was found to have a high glass transition temperature and exhibit good mechanical properties.

  In addition, it was recognized that patterning was possible by both positive and negative procedures.

  On the other hand, none of the photosensitive resin compositions of the comparative examples had sufficient curability at low temperatures. In addition, there was no level that could be patterned by both positive and negative procedures.

  In addition, although the experiment which changed the ratio of the crosslinking agent in Example 1 into 25 mass parts and 35 mass parts was conducted, the evaluation result was the same tendency as Example 1.

  Moreover, although the experiment which changed the ratio of the photosensitive agent in Example 1 into 8 mass parts and 12 mass parts was conducted, the evaluation result was the same tendency as Example 1.

DESCRIPTION OF SYMBOLS 10 Semiconductor device 20 Semiconductor chip 21 Electrode pad 22 Conductive wire 30 Die pad 40 Lead 50 Mold part 60 Adhesive layer 70 Protective film

Claims (8)

A maleimide copolymer comprising a first repeating unit represented by the following formula (1) and a second repeating unit represented by the following formula (2).

[In formula, X is an organic group containing a C3-C30 alkylene group or a C3-C8 cycloalkyl group. ]   The maleimide copolymer according to claim 1, wherein the organic group is a chain saturated hydrocarbon or a cyclic saturated hydrocarbon.   The maleimide copolymer according to claim 1, wherein the organic group further contains a hydroxyl group.   The maleimide copolymer according to any one of claims 1 to 3, which has alkali solubility. The maleimide copolymer according to any one of claims 1 to 4,
A crosslinking agent capable of crosslinking with the maleimide copolymer;
A photosensitizer,
The photosensitive resin composition characterized by having.   The photosensitive resin composition of Claim 5 whose glass transition temperature of hardened | cured material is 250 degreeC or more. A semiconductor substrate;
A coating layer provided on the surface of the semiconductor substrate and containing a cured product of the photosensitive resin composition according to claim 5 or 6,
A semiconductor device comprising:   An electronic apparatus comprising the semiconductor device according to claim 7.

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