JP3486012B2 - Polyimide siloxane block copolymer, varnish containing the same and method of using the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel polyimide siloxane block copolymer, a film-forming varnish containing the same, and a method of using the varnish. For more details,
The present invention is a resin that is useful in the field of electric and electronic parts and industrial parts where heat and humidity resistance and workability are important, and is excellent in heat resistance, adhesiveness, and wear resistance, and an electrical insulating material,
The present invention relates to a novel polyimide siloxane block copolymer which is a resin useful as various molding materials, coating materials, impregnating materials, etc., a varnish for forming a coating film containing the same, and a method of using the varnish.

[0002]

2. Description of the Related Art In recent years, with the miniaturization and multi-functionalization of semiconductor products, LSI packages tend to be thin and have many pins despite the large size of chips. Along with this, development of a polymer material excellent in heat resistance, adhesiveness, moldability, and electric characteristics is desired, and various proposals have been made. Polyimide resins, polyamide resins, etc. are widely known as heat-resistant polymer materials. In addition to heat resistance, they are also excellent in impact resistance, mechanical properties, solvent resistance, and high molecular electronic materials. Has been noticed as. But,
Formability, adhesiveness, hygroscopicity, dielectric properties, etc.
A compound with an elastomer such as siloxane having a low hygroscopic property and a low dielectric property has been studied.

[0003]

However, the conventionally proposed polyimide resin and polyamide resin have low compatibility with the elastomer and thus are difficult to form into a composite, and the solubility of the resin synthesized with a desired composition is also high. Getting worse,
There was a difficulty in using it as a coating. Therefore, when it is used as a polymer electronic material, it is desired to realize a polymer material having excellent properties in terms of solvent solubility, moldability, etc. in addition to heat resistance, adhesiveness, and electrical properties. Therefore, an object of the present invention is to provide a polyimide siloxane block copolymer which satisfies the above characteristics and is useful as a high-reliability polymer material. Another object of the present invention is to provide a film-forming varnish containing the above-mentioned polyimidesiloxane block copolymer and a method for using the varnish.

[0004]

The present inventors have completed various aspects of the invention as a result of various studies to solve the above-mentioned problems in the prior art. The polyimide siloxane block copolymer of the present invention is 3,3 ′, 4,4 ′.
A block copolymer comprising a polyimide structural unit formed of biphenyltetracarboxylic dianhydride and a 4,4′-diaminodiphenylmethane derivative and a diaminodimethylsiloxane structural unit, having an intrinsic viscosity of 0.1 to
It is characterized by having a structure represented by the following general formula (1) of 3.0 dl / g, preferably 0.2 to 2.0 dl / g.

[Chemical 2] (And however, R ¹ and R ² are each a hydrogen atom, or an alkyl group having 1 to 3 carbon atoms. However, they .x and y not simultaneously hydrogen atoms, respectively x =. 1 to 150, y = 1 to an integer of 30. n is 1
Represents an integer of 100. )

The polyimide siloxane block copolymer varnish for forming a film of the present invention is obtained by dissolving the polyimide siloxane block copolymer represented by the general formula (1) in an organic solvent and has a viscosity of 100 to 50,000 centipoise. It is in the range of.

The method of use of the present invention is characterized in that the above-mentioned polyimide siloxane block copolymer varnish is applied to a suitable substrate and dried. In the method of use of the present invention, when a substrate on which a conductive circuit is formed is used, a protective film or an insulating film for the conductive circuit can be formed. Further, another one of the methods of use of the present invention is to form a patterned coating film, which is obtained by applying the polyimide siloxane block copolymer varnish for forming a coating film described above to a suitable substrate and drying it to obtain an alkaline aqueous solution. It is characterized in that a pattern is formed by etching with a basic etching solution such as.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below. The polyimide siloxane block copolymer of the present invention can be easily produced by a known general method. That is, 3,3 ', 4,4'-
After heating the biphenyltetracarboxylic dianhydride and the 4,4′-diaminodiphenylmethane derivative in a reaction solvent between room temperature and 60 ° C. to produce a polyamic acid represented by the following general formula (2), The diaminodimethylsiloxane represented by the general formula (3) is added and reacted with this polyamic acid to produce a block-copolymerized polyamic acid, which is further heated at 150 to 250 ° C. for about 30 minutes to 5 hours for imide ring closure. , Can be synthesized by adding the reaction product to a poor solvent such as methanol.

[Chemical 3] (In the formula , R ¹ , R ² , x, and n have the same meanings as described above.)

[0008]

[0009] 3, 3 ', in the case of using 4,4'-biphenyltetracarboxylic acid dianhydride, is preferably used because it significantly improves the solvent solubility without reducing the thermal or electrical properties . With this dianhydride,
The processability can be improved without sacrificing the heat resistance and moisture resistance of the polyimide siloxane block copolymer, and the polyimide siloxane block copolymer having the best electrical characteristics can be obtained.

Examples of the 4,4'-diaminodiphenylmethane derivative used in the present invention include bis (4-amino-3-methylphenyl) methane and bis (4
-Amino-3,5-dimethylphenyl) methane, bis (4-amino-3-ethylphenyl) methane, bis (4
-Amino-3-ethyl-5-methylphenyl) methane,
Bis (4-amino-3,5-diethylphenyl) methane, bis (4-amino-3-propylphenyl) methane, bis (4-amino-3,5-dipropylphenyl)
Methane, bis (4-amino-3-isopropylphenyl) methane, bis (4-amino-3,5-diisopropylphenyl) methane, bis (4-amino-2,3-dimethylphenyl) methane, bis (4-amino) Examples include, but are not limited to, −2,5-dimethylphenyl) methane and the like. Moreover, you may use these individually or in combination.

Of these, particularly preferred 4,4'-diaminophenylmethane derivatives are bis (4-amino-3,5-dimethylphenyl) methane and bis (4-amino-3,5-diethylphenyl). Methane, bis (4-
Amino-3-ethyl-5-methylphenyl) methane 3
One type of diamine can be mentioned. When these diamines are used alone or in combination of two or more, the solvent solubility is remarkably improved without lowering the thermal characteristics such as heat resistance and electrical characteristics of the polyimidesiloxane block copolymer, and the processability may be improved. it can.

In the present invention, the above 3, 3 ′, 4,
4'-biphenyltetracarboxylic dianhydride and 4,4 '
-The polyamic acid formed by heating with the diaminodiphenylmethane derivative needs to be in the range of x = 1 to 150, and is preferably set in the range of 1 to 50. x
If the value of exceeds 150, problems such as poor film formability in processing the resin are likely to occur.

The diaminodimethylsiloxane used in the invention for reacting with the above polyamic acid is a diaminodimethylsiloxane having an aminopropyl terminal in which the repeating unit of the siloxane bond is 1 to 100.
Among them, particularly preferable diaminodimethylsiloxane for the present invention has n in the range of 1 to 17. When the value of n exceeds 100, the solubility in a solvent becomes poor, which causes a problem in use.

The reaction solvent used in the synthesis of the polyimide siloxane block copolymer is, for example,
N, N- dimethylformamide, N, N- dimethylacetamide, N- methyl-2-pyrrolidone, N- methyl caprolactam, Jimechirusu Le sulfoxide, 1,3-dimethyl-2-imidazolidinone, tetramethylurea, pyridine, dimethyl Examples thereof include sulfone and hexamethylphosphoric acid triamide-m-cresol.

If necessary, a solvent other than these may be added to the reaction system to generate a polyamic acid. For example, a low hydrocarbon organic solvent having a carbon number of 10 or less, a cyclic hydrocarbon organic solvent, an aromatic organic solvent such as benzene, toluene, xylene, or the like, which is a low polar organic solvent that does not inhibit the amic acid formation reaction, or Tetrahydrofuran,
An ether organic solvent such as 1,4-dioxane or diglyme can be added to the reaction system. At this time, a protonic acid such as p-toluenesulfonic acid or a dehydrating agent such as acetic anhydride can be used as the imide ring-closing catalyst.

In the present invention, under the above reaction conditions ,
When the total number of moles of 4,4'-diaminophenylmethane derivative and diaminodimethylsiloxane is equal to the number of moles of 3 ', 4,4'-biphenyltetracarboxylic dianhydride , high polymerization is achieved. A certain degree of polyimide copolymer is obtained. Further, it is possible to obtain one having a small average degree of polymerization by using one of the components in excess.

In the present invention, the use ratio of diaminodimethylsiloxane can be set arbitrarily, but it is 5 to 10 mol% of the total amount of the diamine compound, and the dimethylsiloxane structural unit contained in the final reaction product. Is preferably used in a range such that the content of 5 to 15% by weight. In the polyimidesiloxane block copolymer of the present invention, when the content of the dimethylsiloxane structural unit is in the range of 5 to 15% by weight, moisture resistance and adhesiveness can be improved without sacrificing heat resistance and processability. It can be imparted and the electric characteristics can be further improved.

The polyimidesiloxane block copolymer of the present invention produced as described above has y = 1 to 30,
It is preferably in the range of 1 to 20 and has an intrinsic viscosity (resin concentration: 0.5 g / dl of dimethylacetamide solution of 30).
Means a measured value in ° C) is 0.1 to 3.0 dl
/ G is necessary, and preferably 0.2
It is set in the range of up to 2.0 dl / g. Intrinsic viscosity is 0.
When it is lower than 1 dl / g, a sufficient film cannot be obtained, and when it is higher than 3.0 dl / g, workability is deteriorated and a problem in use occurs.

The above-mentioned polyimide siloxane block copolymer of the present invention has excellent solvent solubility, and examples thereof include low boiling point solvents such as chloroform, tetrahydrofuran, cyclohexanone, N-methyl-2-pyrrolidone,
It is soluble in amide solvents such as N, N-dimethylacetamide, N, N-dimethylformamide, and 1,3-dimethyl-2-imidazolidinone, and is characterized by high solubility. Further, the polyimidesiloxane block copolymer of the present invention has excellent heat resistance, adhesiveness, solvent solubility, moldability, and electrical characteristics.

The polyimidesiloxane block copolymer of the present invention has the above-mentioned excellent properties and is therefore very useful as a film-forming material. For example, the polyimide siloxane block copolymer of the present invention an organic solvent, for example,
A coating solution obtained by dissolving it in N, N-dimethylacetamide, tetrahydrofuran or the like and adding other resin, pigment or the like, if necessary, can be preferably used as a film-forming varnish. In the present invention, the varnish for forming a film is preferably adjusted so that the solution viscosity thereof is in the range of 100 to 50,000 centipoise (cp).
When the solution viscosity is lower than 100 cp, a sufficient film cannot be obtained, and when it is higher than 50,000 cp, the workability is deteriorated. A coating-forming varnish consisting of a coating solution adjusted to be in the above solution viscosity range is applied onto a substrate,
By drying, a coating such as a heat-resistant film, heat-resistant coating film, heat-resistant adhesive film or the like can be formed.

The substrate is not particularly limited, and examples thereof include glass, metal plates such as aluminum plates, plastic materials, and composite materials such as FRP. It is preferable to use an aluminum plate as the substrate because the varnish for forming a film has excellent adhesiveness. Further, as the substrate, a substrate having an electric circuit formed on a plastic substrate can be used. In that case, the film formed by the film-forming varnish of the present invention functions as a protective film or an insulating film.

The polyimide siloxane block copolymer of the present invention contains a releasing agent such as pigments, dyes, conductive inorganic materials, inorganic fibers, organic fibers, waxes, flame retardants, and antioxidants, if necessary. It can also be used as a mixture with additives such as ultraviolet absorbers, light stabilizers, inorganic compounds, organic compounds and other resins.

The polyimidesiloxane block copolymer of the present invention can be easily etched with an alkaline aqueous solution such as NaOH or KOH, a hydrazine solution, or a basic etching solution such as an amine solvent such as ethylenediamine. It is useful for forming a patterned film. In particular, it is useful as a circuit board material used around a semiconductor chip showing high precision and high reliability. For example, a film-forming varnish obtained by dissolving the above-mentioned polyimide siloxane block copolymer in an appropriate organic solvent is applied onto an appropriate substrate such as a semiconductor and dried to form a film, and then a photoresist material To form a photosensitive layer, which is exposed to light, and developed with a developing solution to elute and remove the unexposed portion, and then a basic etching solution is used to remove the film on the portion where the resist image is not formed by etching. A patterned coating can be formed by peeling and removing the photosensitive layer in the resist image portion. The formed patterned film has excellent heat resistance and electrical insulation, and can be used as an insulating film used around a semiconductor chip.

[0024]

The present invention will be described in detail below with reference to examples, but the present invention is not limited thereto. Example 1 Bis (4-amino-3-ethyl-5-methylphenyl) methane 5.649 in a 300 ml three neck round bottom flask.
g (20.0 mmol) and N-methyl-2-pyrrolidone (35 ml) were added, and the mixture was dried under an atmosphere of dry nitrogen at 5 ° C. to give 3,3 ′,
4,4'-biphenyltetracarboxylic dianhydride 6.3
04 g (21.4 mmol) was gradually added as a powder and reacted at 40 ° C. for 3 hours to give a polyamic acid (x = 1.
5) was prepared. Then, a dimethyl siloxane oligomer having amino groups at both ends (X, manufactured by Shin-Etsu Silicone Co., Ltd.
22-161AS, n = 10) 1.305 g (1.4 mmol) was dissolved in 35 ml of tetrahydrofuran, added to the reaction system, and further reacted at 40 ° C. for 3 hours. To this reaction solution, 5.1 g of pyridine and 6.6 g of acetic anhydride were added, and imide ring closure reaction was carried out at 80 ° C. for 2 hours. After the reaction was completed, the polymer solution was poured into 2 liters of methanol to precipitate the polymer. After filtration, the polymer was washed in hot methanol to remove unreacted oligomers.
After filtration, vacuum drying was performed to obtain a polyimidesiloxane block copolymer (y = 10) of the present invention having a yield of 98.0% and a siloxane content of 10% by weight. The viscosity value of this polyimidesiloxane block copolymer measured by an E-type viscometer was 4,600 cp at 25 ° C. in N-methyl-2-pyrrolidone at a polymer solution concentration of 10% by weight. In addition, the IR spectrum (KBr tablet method) was measured to confirm the structure. As a result, the absorption of an imide carbonyl group at around 1720 cm ⁻¹ and the absorption group of a methyl group that is a substituent on the silicon atom at 1840 cm ⁻¹ were 1010 to 1010. 1100 cm
^-1 showed absorption based on the siloxane skeleton, confirming that it was the target compound.

[0025]

[0026]

Example 2 Using the polyimidesiloxane block copolymer synthesized in Example 1, a varnish consisting of an N, N-dimethylacetamide solution having a solution viscosity of 1500 cp was prepared. A varnish made of this polymer solution was applied to a glass plate by a casting method and the solvent was removed by a vacuum dryer, whereby a transparent film was obtained. The glass transition temperature: Tg of the polyimidesiloxane block copolymer of Example 1 was 280 ° C., the thermal decomposition initiation temperature in air: Td was 340 ° C., and the frequency was 100.
The dielectric constant at room temperature in KHz: ε'was 2.7, and the moisture absorption rate was 0.3% .

[0028] There use polyimide siloxane block copolymer synthesized in Example 3 Example 1, N - to prepare a varnish solution viscosity 1000cp consisting methyl-2-pyrrolidone solution. The above varnish is applied on a conductive circuit on which wiring has been formed and on an aluminum plate by using a spin coater, and then at 150 ° C. for 1 hour, 200
Heat treatment was performed at 30 ° C. for 30 minutes to form a thin film having a thickness of 1 to 5 μm. On top of that, cyclized rubber negative photoresist (OM
R83, manufactured by Tokyo Ohka Kogyo Co., Ltd.) was applied using a spin coater and dried at 90 ° C. for 20 minutes to form a resist thin film of 1 μm. A photomask was brought into close contact with this thin film, and exposure (5 mJ / cm ² × 5 seconds) was performed through the photomask. After the exposure, the thin film is immersed in a developing solution (OMR developing solution, manufactured by Tokyo Ohka Kogyo Co., Ltd.) at 20 ° C. for 2 minutes.
The unexposed portion of the thin film was eluted and removed. Next, the exposed portion of the polyimide siloxane block copolymer film not covered with the photoresist film is immersed in a mixed solution of hydrazine monohydrate and ethylenediamine (7: 3) at a temperature of 30 ° C. for 5 minutes. By etching. After the etching treatment, the polyimide siloxane block copolymer thin film covered with the photoresist film is immersed in a resist stripping solution (S-502, manufactured by Tokyo Ohka Kogyo Co., Ltd.),
The photoresist coating was stripped off. After removing the photoresist coating, heat treatment was carried out at 200 ° C. for about 30 minutes to obtain a pattern-formed product composed of a polyimidesiloxane block copolymer thin film. It was confirmed that each of the obtained patterned products composed of the polyimide siloxane block copolymer thin film had a sharp pattern with sharp edges. Further, the pattern formed product did not deform even when heated to 250 ° C.

[0029]

INDUSTRIAL APPLICABILITY The polyimide siloxane block copolymer of the present invention has improved solvent solubility and compatibility with other resins, is not only excellent in heat resistance and processability, but also has low moisture absorption. It has a high dielectric constant and a low dielectric constant, and has excellent adhesiveness. Further, the polyimidesiloxane block copolymer of the present invention has not only film-forming properties and excellent adhesiveness, but also high flexibility and high followability to the substrate, so that the thermal change of the substrate It has excellent followability to irregularities and the like on the surface of the substrate and can form a strong coating film. Therefore, the polyimide siloxane block copolymer of the present invention is an extremely useful material in the fields of electrical insulating materials, coating materials, electronic parts and the like. That is, the coating film formed using the polyimidesiloxane block copolymer of the present invention has a low dielectric constant and a high insulating property, and is therefore useful as a protective film or an insulating film for a conductive circuit. Furthermore, since the coating can be etched with a basic etching solution, it is possible to form a patterned coating,
It is useful for making circuit boards.

Front page continued (58) Fields surveyed (Int.Cl. ⁷ , DB name) C08G 73/00-73/26 CAPLUS (STN) REGISTRY (STN)

Claims (9)

(57) [Claims] 1. 3,3 ′, 4,4′-biphenyltetra
A block copolymer composed of a polyimide structural unit formed from a carboxylic dianhydride and a 4,4'-diaminodiphenylmethane derivative and a dimethylsiloxane structural unit, having a structure represented by the following general formula (1): Polyimide siloxane block copolymer having an intrinsic viscosity of 0.1 to 3.0 dl / g. [Chemical 1] (And however, R ¹ and R ² are each a hydrogen atom, or an alkyl group having 1 to 3 carbon atoms. However, they .x and y not simultaneously hydrogen atoms, respectively x =. 1 to 150, y = 1 to an integer of 30. n is 1
Represents an integer of 100. ) 2. A 4,4'-diaminodiphenylmethane derivative
The conductor is bis (4-amino-3,5-dimethylphenyl)
) Methane, bis (4-amino-3,5-diethylphene)
Nyl) methane and bis (4-amino-3-ethyl-5)
-Methylphenyl) methane or one selected from
2. The porcelain according to claim 1, characterized in that
Mid-siloxane block copolymer. 3. A siloxane having a dimethylsiloxane structural unit.
The number of repeating units of the hydrogen bond is 1 to 17
The polyimide film according to claim 1 or 2, which is a characteristic of the polyimide film.
Roxane block copolymer. 4. A polyimide siloxane block copolymer
Content of the dimethylsiloxane structural unit in 5 to 1
Claims 1 to 5, characterized in that it is 5% by weight.
Polyimide siloxane block according to any one of 3
Polymer. 5. The method according to any one of claims 1 to 4.
Put the polyimide siloxane block copolymer in an organic solvent
It has a viscosity of 100-50,000 cm.
A film-forming poly-characterized in poise range
Mid-siloxane block copolymer varnish. 6. The polyimidesiloxane according to claim 5.
Apply the block copolymer varnish to the substrate and dry
A method of using the varnish, which is characterized in that 7. A conductive circuit is formed on a substrate.
The method of using the varnish according to claim 6, characterized in that: 8. The substrate is an aluminum plate
7. The method of using the varnish according to claim 6. 9. The polyimidesiloxane according to claim 5.
The block copolymer varnish is applied to a substrate, dried,
Pattern by etching with a basic etching solution
A method of using a varnish, which comprises forming a varnish.