JPH07304871A - Polyimide precursor and photosensitive resin composition and electronic device using the same - Google Patents

Abstract

PURPOSE:To obtain a polyimide precursor, having a specific recurring unit, excellent in transparency at a specific wavelength and heat resistance after thermal imidation and useful for resin compositions, etc., for passivation films such as electronic devices. CONSTITUTION:This polyimide precursor has a recurring unit expressed by formula I [A is a group expressed by formula II, III or IV; B is 2,3,5,6-tetra-1-3C alkylphenylene, 2,3,6-tri-1-3C alkylphenylene(1,4),3,3'5,5'-tetra-1-3C alkylbiphenylylene(4,4') or 3,3',5-tri-1-3C alkylbiphenylylene(4,4'); (n) is 14-270].

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to 365 nm (hereinafter referred to as i
The present invention relates to a polyimide precursor, a photosensitive resin composition, which is a polyimide excellent in transparency after being thermally imidized, and an electronic device using the same.

[0002]

2. Description of the Related Art In the semiconductor industry, materials for insulating layers and passivation films and interlayer insulating materials for LSIs and multilayer printed wiring boards are required to have excellent insulating properties and heat resistance. Various polyimides have been proposed as materials suitable for this. However, since polyimide does not have a photosensitive group, after applying the polyimide precursor varnish for LSI etc.,
After thermal imidization, a chemical etching process is performed on it through a photoresist to form a relief pattern in polyimide. Therefore, there is a problem that the process steps are extremely long.

As a method for simplifying this, a photosensitive polyimide in which a photosensitive group is added to polyimide or polyamic acid as a polyimide precursor has been proposed. Specifically, JP-B-49-17374 (combination of polyimide precursor and dichromic acid), JP-A-55-30207 (polyimide precursor and photosensitive group covalently bonded), JP-A-60. No. 1001433 (in which a polyimide precursor and a photosensitive group are ionically bonded) has been proposed and partially put into practical use. As another example, as described in JP-A-63-47142, it is described that a benzophenonetetracarboxylic dianhydride and a polyimide having a diaminodiphenylmethane unit are self-crosslinking and photosensitive.

However, nothing has been found in consideration of transparency and heat resistance on the short wavelength side. In the field of semiconductors, miniaturization of wiring of semiconductor elements is indispensable in order to cope with an increase in memory capacity. Therefore, the wavelength used for resist exposure is becoming shorter, and the adoption of i-line resist is rapidly progressing. When the resist processing for i-line is decided, it is indispensable for the photosensitive polyimide to be compatible with i-line because the stepper device is shared. Further, since the semiconductor element has a solder connection step when it is surface-mounted on a printed circuit board, the photosensitive polyimide needs to have a heat resistance of about 330 ° C. including a margin. Therefore, these photosensitive polyimides are required to have both transparency of the polyimide precursor at the i-line and heat resistance after thermal imidization.

However, in the prior art, the transparency and heat resistance of polyimide were in conflict. Since Kapton, which is a commercially available polyimide manufactured by DuPont, is an aromatic type, it has a high glass transition temperature (hereinafter abbreviated as Tg) of 340 ° C. and is excellent in heat resistance. However, as can be seen from the appearance of the brown-colored polyimide, the polyimide precursor shows a large decrease in transparency from around 500 nm and a transmittance at 400 nm of 5 at a thickness giving a polyimide film of 10 μm or more.
% Or less, and 0% at 365 nm. As can be seen from this example, the conventional polyimide is excellent in heat resistance, but insufficient in transparency.

It has been suggested to prevent formation of CT complex (Charge Transfer) in order to improve transparency. Specifically, introduction of a polyimide aliphatic polyimide containing a fluorine-containing polyimide ether group or a sulfone group. However, has a problem in adhesion and has low heat resistance. Connectivity is an important issue for insulating layers, and fluorine-containing polyimide cannot be used because of its adhesiveness.

Generally, photosensitive polyimide can be patterned by the following steps. The varnish coating of the photosensitive polyimide precursor onto the substrate can be performed by means of spin coating using a spinner, dipping, spray printing, etc., and can be appropriately selected. The coating film thickness can be adjusted by the coating means, varnish concentration and the like. A composition which has become a film of a precursor which does not become sticky on a supporting substrate through a drying process, and a high pressure mercury lamp centered at a wavelength of 200 to 500 nm through a photomask, an ultrahigh pressure mercury lamp, a metal halide lamp, a xenon lamp, a carbon arc. Irradiates light from lamps, chemical lamps, etc. to cause photo-curing and decomposition by photoreaction.
Next, the relief is formed on the support by eluting the uncured portion and the decomposed portion with the developing solution. This relief pattern is a polyimide precursor and is 150-45.
A polyimide pattern is obtained by treating at a temperature selected from the range of 0 ° C.

The developer is γ-butyl lactone, 1-acetoxy-2-methoxyethane, diethylene glycol dimethyl ether, N-methyl-2-pyrrolidone, N, N.
A solvent such as -dimethylacetamide, N, N-dimethylformamide, dioxane, dimethylsulfoxide, toluene, xylene, water, methanol, ethanol, n-propanol, isopropanol can be used. These may be used alone or in combination of two or more.

[0009]

As described above, in the above-mentioned prior art, when the polyimide precursor has a thickness which gives a polyimide film having a thickness of 10 μm or more after imidization, i-line transmittance is high and thermal imidization is performed. A polyimide structure having excellent heat resistance has not been proposed. Therefore, there has been no one satisfying the application to the semiconductor integrated circuit, which is required to have higher performance and smaller size. The present invention provides a polyimide precursor having a high i-line transmittance, excellent transparency and heat resistance, a photosensitive resin composition having a photosensitizing group introduced therein, and various electronic devices using the same. The task is to do.

[0010]

In order to solve the above problems, the present invention provides a polyimide precursor having a repeating unit represented by the following general formula (1).

[0011]

[Chemical 1] (However, in the formula, A is the following formula 2, B is the following formula 3, R is an alkyl group having 1 to 3 carbon atoms, and n is 14 to 270)

[Chemical 2]

[Chemical 3]

The above polyimide precursor has a transmittance of 2 at a wavelength of 365 nm at a thickness of the polyimide precursor that gives a polyimide film of 10 μm or more after imidization.
It is 0% or more, and its glass transition temperature after thermal imidization is 330 ° C. or more. As described above, in the present invention, in order to achieve both transparency and heat resistance, when three or more positions of the four ortho positions of the amide group of the repeating unit of the polyamic acid are replaced with alkyl groups, i-line Has excellent transmittance at
It was found that the Tg after imidization also shows 330 ° C. or higher,
The present invention has been reached.

In the present invention, a photosensitive resin composition is prepared by introducing a photosensitizing group into the above polyimide precursor. Further, in the present invention, a photosensitivity-imparting group is introduced into a mixed polyimide precursor composed of 10 to 70 wt% of the polyimide precursor of Chemical formula 1 and 30 to 90 wt% of the polyimide precursor having a repeating unit shown in Chemical formula 4 below. Resin composition.

[0014]

[Chemical 4] (However, in the formula, R ₁ is a tetravalent aromatic group, R ₂ is a divalent organic group, and n is 12 to 270.)

The method of adding a photosensitive group to the polyimide precursor of the present invention is described in Polyfile, pp. As described in the 14-18, February issue (1990), the ionic bond method, the covalent bond method, and the method of adding an acid generator or a chlorine generator have been proposed so far. It can be used arbitrarily. As these photosensitizing compounds, 2-nitrobenzyl alcohol, α-methyl-nitrobenzyl alcohol, α-ethyl-nitrobenzyl alcohol,
2,4-dinitrobenzyl alcohol, methacroyl ethanol, β-oxyethyl methacrylate, dimethylaminoethyl methacrylate, isocyanate ethyl acrylate, isocyanate propyl acrylate, isocyanate hexyl ethyl methacrylate, (((2
-Nitrobenzyl) oxy) carbonyl) hexylamine, bis (((2-nitrobenzyl) oxy) carbonyl) hexane, p-nitrobenzyl-9,10-diethoxyanthracene-2-sulfonate and the like.

The polyamic acid of the polyimide precursor of the present invention is described in J. As described in Polymer Sci., A-1, 3, 1373 (1965), a method obtained by melt polycondensing equimolar tetracarboxylic acid dianhydride and diamine in a polar solvent is most industrially Are better. Examples of the polar solvent used in the polyamic acid synthesis include n-methyl-2-pyrrolidone (hereinafter abbreviated as NMP), dimethylacetamide, dimethylformamide, diglyme, phenol, toluene, xylene, etc., which may be used alone or in combination of two or more. Can be used.

The tetracarboxylic dianhydride which can be used in the general formula 1 is pyromellitic dianhydride,
Examples include 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride and 3,3 ″, 4,4 ″ -p-terphenyltetracarboxylic dianhydride. These can be used alone or in combination of two or more. Examples of the diamine that reacts with the tetracarboxylic dianhydride include tetramethyl-1,4-phenylenediamine, tetraethyl-1,4-phenylenediamine, tetrapropyl-1,4-phenylenediamine, and trimethyl-1,4-phenylene. Diamine, triethyl-1,4-
Phenylenediamine, tripropyl-1,4-phenylene dimian, 3,3 ', 5'-trimethyl-4,4'-
Diaminobiphenyl, 3,3 ', 5'-triethyl-
4,4'-diaminobiphenyl, 3,3 ', 5'-tripropyl-4,4'-diaminobiphenyl and the like can be mentioned. These amine compounds may be used alone or in combination of two or more.

The tetracarboxylic acid dianhydride which can be used in the general formula 4 is pyromellitic dianhydride,
3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, 3,3', 4,4'-benzophenone tetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride 2,3,6,7-naphthalenetetracarboxylic dianhydride, 2,3,5,6-pyridinetetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 4,4′-sulfonyldiphthalic acid dianhydride, 3,3 ″, 4,4 ″ -p-terphenyltetracarboxylic dianhydride, 3,3 ″, 4,4 ″
-M-terphenyl tetracarboxylic dianhydride and the like.

Examples of the diamine that reacts with the tetracarboxylic dianhydride include o-tolidine, p-phenylenediamine, 2,4-diaminodiphenyl ether, and 4,4 '.
-Diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfide, 4,
4 ″ -diaminoterphenyl, 4,4 ″ -diaminodicyclohexylmethane, 1,5-diaminonaphthalene, 4,4′-bis (p-aminophenoxy) biphenyl, 4,4′-bis (m-aminophenoxy) ) Diphenyl sulfone, 2,2-bis (4- (p-aminophenoxy) phenyl) propane, 3,3'-dimethyl-4,
4'-diaminodiphenylmethane, 2,7-diaminofluorene, acetoguanamine, 3,3'-dimethoxybenzidine, m-phenylenediamine, 2,6-diaminoanthraquinone, 2,6-aminotoluene, 2,5-diaminopyridine, 2,6-diaminopyridine, 2,5-
Diaminotoluene, 2,3-diaminopyridine, 3,4
-Diaminopyridine, 4,4'-diaminobenzophenone, 4,4'-bis (p-aminophenoxy) diphenyl sulfone, benzoguanamine, 2,7-diaminonaphthalene, 3,4-diaminotoluene, m-xylenediamine, p- Examples include xylenediamine, 4,4'-dithiodianiline, o-phenylenediamine, 4,4'-methylenebis (2-methylcyclohexylamine) and the like.

The number average molecular weight of the polyimide precursor (hereinafter,
(Mn is abbreviated) is an important property that affects solubility and mechanical properties. Specifically, it is 1 in terms of polystyrene by gel permeation chromatography (GPC).
0000 to 100000 (where n in the chemical formula 1 is 14 to 27)
(Corresponding to 0) is preferred. If it is less than 10,000, the mechanical properties are deteriorated, and in some cases, the polyimide film is not formed. If it exceeds 100,000, the solubility is lowered, which is not preferable. The above-mentioned photosensitive resin composition of the present invention can be suitably used as a passivation film. Further, the passivation film is formed on the bonding pad, the through hole is formed, the bonding pad and the lead frame are connected, and the semiconductor device can be obtained by sealing with a sealant.

[0021]

The polyamic acid of the present invention has excellent transparency and heat resistance because it has three or more substituents at the ortho positions of the amide group in the repeating unit of the polyamic acid. Specifically, the polyimide precursor has a transmittance of 20% or more for i-line at a thickness that gives a polyimide film having a film thickness of 10 μm or more after imidization, and its Tg after thermal imidization is 330 ° C. or more. is there. Therefore, a photosensitive resin composition having excellent heat resistance, which can be exposed to i-rays, can be obtained.

The i-line transmittance of the coating film obtained from the photosensitive resin composition of the present invention was measured using a 557 type two-wavelength spectrophotometer manufactured by Hitachi. A quartz glass plate having a thickness of 0.5 mm and a diameter of 100 mm was used as the substrate for measuring the transmittance. The coating thickness is a thickness that gives a polyimide film of 10 μm or more, and is specifically 20 to 22 μm. Tg
Sets a polyimide film having a thickness of 10 μm and a width of 6 mm in a thermophysical tester (manufactured by Vacuum Riko Co., Ltd., TMA-3000 type), and applies a load of 0.5 g per 1 μm of the film thickness to stretch the film in a tensile mode. It was measured. The point of intersection of the tangents at which the tangents of the elongation temperature curve differ greatly was taken as Tg.

As an example of an electronic device using the photosensitive resin composition of the present invention, a schematic diagram for explaining a method of manufacturing a resin-sealed semiconductor device is shown in FIG. That is, as shown in FIG. 1A, aluminum wiring 2 was formed on an LSI chip 1 to form a 50 μm square bonding pad 3. Subsequently, as shown in (b), the photosensitive resin composition 5 of the present invention was applied using a spinner whose rotation speed was adjusted so that the polyimide thickness was 10 μm.

In (c), after preliminary drying at 80 ° C. for 10 minutes,
A photomask was placed and exposed with i-line. Further, development and thermal imidization were performed to form through holes of 50 μm square.
In (d), the bonding pad 3 having a through hole and the lead frame 8 are connected by a bonding wire 7, and the whole is sealed with an epoxy-based or phenol-based sealing resin to produce a resin-sealed semiconductor device. This polyimide film is S
Excellent adhesion to iO ₂ , PSG (phosphosilicate glass), and SiN _2, and particularly excellent adhesion to epoxy-based or phenol-based encapsulating resin, so that moisture intrusion from the interface is prevented and Corrosion of metal such as aluminum forming a circuit can be prevented, and the reliability of the LSI is improved.

[0025]

EXAMPLES The present invention will be described in detail below with reference to examples. Example 1 (1) Synthesis of Polyamic Acid The polyamic acid was replaced with nitrogen in a four-necked flask equipped with a thermometer, a nitrogen blowing tube, a calcium chloride tube, and a stirrer, and then NMP as a reaction solvent was added. Then, diamine is added and stirred to completely dissolve it. Then tetracarboxylic dianhydride was added. The compounding amount of the diamine and the tetracarboxylic dianhydride is 14 wt% and is equimolar (hereinafter referred to as NV 14%). NMP is 86 wt%.

The reaction temperature is room temperature and the stirring speed is 150 rpm.
I did it in. The system that generated heat after the start of the reaction was cooled with water. The reaction time was 8 hours. If the viscosity of the varnish increased and the stir bar became entangled before that, the reaction was terminated at that point. A system having a varnish viscosity at 25 ° C. of 50 poise or less even after being reacted for 8 hours or more was further reacted for 1 day or more.
If the viscosity of the varnish after reaction is 500 poise or more, 70
The viscosity of the varnish was adjusted to about 100 poises by heating to -80 ° C to hydrolyze the polyamic acid.

(2) Synthesis of photosensitive resin composition 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, tetramethyl-1,4-phenylenediamine, N
300 g of polyamic acid was synthesized by the above method using MP,
Further, 83.0 g of glycidyl methacrylate was added and the temperature was 60 ° C.
The reaction was carried out at a constant temperature for 48 hours. To 150 g of this varnish, 2.6 g of initiator 1-phenyl-3-ethoxy-propanetrione-2-benzoyloxime and 2.4 g of 4,4'-bis (diethylamino) benzophenone were added and dissolved and stirred. Then, a membrane having a pore size of 5 μm was added. It pressure-filtered with the filter and the photosensitive resin composition was obtained.

(3) Exposure Next, this was spin-coated on a silicon wafer to a thickness giving a polyimide film of 10 μm or more. This was placed in an air circulation dryer at 80 ° C. for 10 minutes and dried to such an extent that the coated surface was not sticky. The i-line transmittance at that time is 4
It was 5%. 500 through a photomask on this coating
Irradiation with 300 mJ / cm ² of i-line was performed with a W ultra-high pressure mercury lamp. Next, add 2% choline hydroxide to the silicone wafer.
Aqueous solution / isopropyl alcohol (volume ratio = 95: 5)
After developing with the developer of No. 1 and rinsing with water, a photomask pattern was formed. This was heated in a nitrogen atmosphere from a room temperature to 350 ° C. with a circulation dryer at a temperature rising rate of 2 ° C./min and held at 350 ° C. for 30 minutes to obtain a polyimide pattern. Its Tg was 361 ° C.

Example 2 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, tetramethyl-1,4-phenylenediamine, N
Polyamic acid was synthesized by the above method using MP. To 20 g of this varnish was added 0.15 g of 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one and 0.02 of 2-isopropylthioxanthone.
g was added and pressure-filtered with a membrane filter having a pore size of 5 μm to obtain a photosensitive resin composition.

Then, this was applied to the same film thickness as in Example 1 and dried. At that time, the i-line transmittance was 43%. Further, through a photomask on the coating film on the silicon wafer, i-line is irradiated at 300 mJ / cm ² with a 500 W ultra-high pressure mercury lamp.
Irradiated. After exposure, it was developed with a mixed solution of NMP / ethanol / 2% tetramethylammonium hydroxide aqueous solution (weight ratio = 1/4/5), and rinsed with ethanol to obtain a relief pattern. This is heated in a nitrogen atmosphere at a heating rate of 2
Increase the temperature from room temperature to 350 ° C with a circulation dryer at
It was kept at 350 ° C. for 30 minutes to obtain a polyimide pattern. Its Tg was 380 ° C.

Example 3 Polyamic acid was synthesized by the above method using trimethyl-1,4-phenylenediamine and NMP to prepare a photosensitive resin composition according to Example 1, which was spin-coated after filtration.
A polyimide pattern was obtained by drying, exposing, developing and thermal imidizing. Its Tg is 352 ° C and the transmittance of the coating film is 45%.
Met.

Example 4 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride and 3,3', 5,5'-tetramethyl-4,4'-
A polyamic acid solution was synthesized from diaminobiphenyl and NMP according to Example 1. To this polyamic acid solution, tetracarboxylic dianhydride and an equivalent amount of [((2,6-dinitrobenzyl) oxy) carbonyl] cyclohexylamine were added and pressure-filtered to obtain a photosensitive resin composition.
Spin coating, drying and exposure are carried out in accordance with Example 1,
It was developed with water / methanol (volume ratio 1/1) and thermally imidized to obtain a polyimide pattern. Its Tg is 366 ° C
The transmittance of the coating film was 39%.

Example 5 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride and 3,3', 5,5'-tetramethyl-4,4'-
A photosensitive resin composition was obtained from diaminobiphenyl and NMP according to Example 2. In a further step, spin coating, drying, exposure, development and thermal imidization were carried out in accordance with Example 2 to obtain a polyimide pattern on a silicon wafer. Its Tg was 362 ° C., and the transmittance of the coating film was 36%.

EXAMPLE 6 3,3 ″, 4,4 ″ -p-terphenyltetracarboxylic dianhydride, trimethyl-1,4-phenylenediamine and NMP in accordance with Example 1 A composition was made. This and the photosensitive resin composition of Example 3 were mixed in an equivalent amount to obtain a mixed photosensitive resin composition. In the subsequent steps, a polyimide pattern was obtained on a silicon wafer according to Example 1. Its Tg is 389 ° C and the transmittance of the coating film is 3
It was 0%.

Example 7 Example 1 from pyromellitic dianhydride, 3,3 ', 5'-trimethyl-4,4'-diaminobiphenyl and NMP
A photosensitive resin composition A was prepared in accordance with. 3 more
A photosensitive resin composition B was prepared according to Example 1 from 3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, diaminodiphenyl ether and NMP. These photosensitive resin compositions were mixed with (A / B = 70/30) to obtain a mixed photosensitive resin composition. In the subsequent steps, a polyimide pattern was obtained on a silicon wafer according to Example 1. Its Tg was 353 ° C. and the transmittance of the coating film was 25%.

Example 8 100 g of varnish from 3,3 ', 4,4'-diphenyltetracarboxylic dianhydride, 3,3', 5-trimethyl-4,4'-diaminobiphenyl and NMP was added with p-nitro. Benzyl-9,10-diethoxyanthracene-2-
12 g of sulfonate was added to obtain a photosensitive resin composition. Spin coating, drying and exposure were carried out in accordance with Example 1, development was carried out with water / methanol (volume ratio 1/1), and thermal imidization was carried out to obtain a polyimide pattern. Its Tg is 366 ° C,
The transmittance of the coating film was 22%.

Example 9 Example 1 from pyromellitic dianhydride, 3,3 ', 5'-trimethyl-4,4'-diaminobiphenyl and NMP
A photosensitive resin composition A was prepared in accordance with. 3 more
A photosensitive resin composition B was prepared according to Example 1 from 3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, diaminodiphenyl ether and NMP. These photosensitive resin compositions were mixed with (A / B = 70/30) to obtain a mixed photosensitive resin composition. In the subsequent steps, a polyimide pattern was obtained on a silicon wafer according to Example 1. Its Tg was 353 ° C. and the transmittance of the coating film was 29%.

Example 10 Example 1 from pyromellitic dianhydride, 3,3 ', 5'-trimethyl-4,4'-diaminobiphenyl and NMP
A photosensitive resin composition A was prepared in accordance with. 3 more
3 ', 4,4'-benzophenone tetracarboxylic dianhydride, 1,4-diaminodiphenyl sulfide and NMP
A photosensitive resin composition B was prepared according to Example 6. These photosensitive resin compositions (A / B = 70/30)
To obtain a mixed photosensitive resin composition. In the subsequent steps, a polyimide pattern was obtained on a silicon wafer according to Example 1. Its Tg was 335 ° C., and the transmittance of the coating film was 22%.

Comparative Example 1 A photosensitive resin composition was prepared from pyromellitic dianhydride, 4,4'-diaminodiphenyl ether and NMP in accordance with Example 1. However, the transmittance of the coating film is 2%
The Tg was 332 ° C.

Comparative Example 2 Example 1 from 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, p-phenylenediamine and NMP
A photosensitive resin composition was prepared according to. However, the coating had a transmittance of 0% and a Tg of 398 ° C.

[0041]

EFFECT OF THE INVENTION The polyimide precursor of the present invention exhibits excellent transparency at i-line as compared with the conventional one, and has a high Tg after thermal imidization. Therefore, the photosensitive resin composition comprising a polyimide precursor having a photosensitive group can be exposed to i-rays and can withstand the solder heat resistance temperature after thermal imidization. The photosensitive resin composition is a passivation film for semiconductor elements,
It is useful as a buffer coat film, α-ray shielding film, etc.
It can be used for an insulating layer such as I.

[Brief description of drawings]

FIG. 1 is a schematic diagram illustrating a method for manufacturing a resin-encapsulated semiconductor device using a photosensitive resin composition of the present invention.

[Explanation of symbols]

1 ... LSI chip, 2 ... Aluminum wiring, 3 ... Bonding pad, 4 ... Tab, 5 ... Photosensitive resin composition, 6 ... Polyimide, 7 ... Bonding wire, 8 ... Lead frame,
9 ... Sealing agent.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Takao Miwa Inventor Takao Miwa 7-1, 1-1 Omika-cho, Hitachi-shi, Ibaraki Hitachi, Ltd. Hitachi Research Laboratory (72) Inventor Akio Takahashi 7-chome, Omika-cho, Hitachi-shi, Ibaraki No. 1 Hitachi Ltd. Hitachi Research Laboratory

Claims (6)

[Claims] 1. A polyimide precursor having a repeating unit represented by the following general formula 1. [Chemical 1] (In the formula, A is the following formula 2, B is the following formula 3, R is an alkyl group having 1 to 3 carbon atoms, and n is 14 to 270) [Chemical 3] 2. A polyimide precursor having a thickness of 10 μm or more after imidization, having a transmittance of 20% or more at a wavelength of 365 nm and a glass transition temperature of 330 ° C. or more after thermal imidization. The polyimide precursor according to claim 1, wherein 3. A photosensitive resin composition obtained by introducing a photosensitizing group into the polyimide precursor according to claim 1. 4. The polyimide precursor 10 according to claim 1.
A photosensitive resin composition, which comprises introducing a photosensitizing group into a mixed polyimide precursor composed of 70 wt% and 30 to 90 wt% of a polyimide precursor having a repeating unit represented by the following chemical formula 4. [Chemical 4] (However, in the formula, R ₁ is a tetravalent aromatic group, R ₂ is a divalent organic group, and n is 12 to 270.) 5. A passivation film using the photosensitive resin composition according to claim 3. 6. The passivation film according to claim 5 is formed on a bonding pad, and after forming a through hole,
A semiconductor device in which the bonding pad and lead frame are connected and sealed with a sealant.