JP2002161248A - Method for bonding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for mutually bonding metal substrates that are metal thin sheets, especially a method for bonding by which bonding can simply be carried out without problems is quality even when a fine pattern is formed on the metal substrate and further a method for bonding by which response can be made in aspects of mass productivity. SOLUTION: This method for mutually bonding metal substrates comprises forming an electrodeposition film on the whole surface or a part of either one or both metal substrates to be bonded by electrodeposition using an electrodeposition liquid prepared by dispersing a polyimide soluble in organic solvents and a hydrophilic polymer in an aqueous solvent, mutually thermocompressing the metal substrates with the electrodeposition film as a bonding medium and bonding the metal substrates.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bonding method for bonding metal substrates, and more particularly, to a method for bonding finely processed metal products typified by shadow masks, lead frames, and the like using a bonding medium. .

[0002]

2. Description of the Related Art In a method of bonding metal substrates together,
A typical example is welding. It is mainly used for thick and large metal bodies such as plates and pipes of industrial plants, and is effective for obtaining adhesive strength. For a thin metal substrate, a method using a tape which is welded by thermoplasticity is used, and for a finely processed metal, a plating method or the like is also used. In the case of welding, a flat layer having a thick build-up joint surface is rarely obtained, and deformation is caused when the metal base is a thin plate. In the case of using a tape which is welded by thermoplasticity, if the thin plate is finely processed, the tape needs to be processed with high precision in order to adhere to a desired location in accordance with the finely processed shape. When the plating layer is used as an adhesive medium, phenomena such as corrosion due to a potential difference between the metal substrate and the plating layer and corrosion of a gap between the plating layers have been concerned.

[0003]

As described above, there are various problems in the bonding between metal substrates when the metal substrate is a thin plate and is subjected to fine processing, and there is a need for a bonding method that can cope with these problems. I was The present invention corresponds to this and is a bonding method for metal substrates in which the metal substrate is a thin plate. In particular, even when the metal substrate is subjected to fine processing, the bonding is easy and the quality is not problematic. It is intended to provide a possible bonding method. Further, it is an object of the present invention to provide a bonding method capable of coping with mass productivity.

[0004]

The bonding method of the present invention is a method for bonding metal substrates together, and uses an electrodeposition solution in which an organic solvent-soluble polyimide and a hydrophilic polymer are dispersed in an aqueous solvent. An electrodeposition film is formed by electrodeposition on the entire surface or a part of one or both metal substrates to be bonded, and the metal substrates are bonded by thermocompression bonding using the electrodeposition film as an adhesive medium. is there. And in the above,
Metal substrate is lead frame, shadow mask, HDD
And one selected from a suspension and a metal sheet for a printer nozzle. Further, in the above, the metal substrate is a sheet body or a continuous body.

[0005]

The bonding of the present invention can be easily performed by the above-described structure by a bonding method between metal substrates having a thin metal substrate, especially when the metal substrate is subjected to fine processing. Thus, it is possible to provide a bonding method capable of bonding without any problem in quality. Furthermore, it is possible to provide a bonding method that can be used in mass production. Specifically, this is a method of bonding metal substrates together, using an electrodeposition solution in which an organic solvent-soluble polyimide and a hydrophilic polymer are dispersed in an aqueous solvent, and forming an electrodeposited film on one or both of the adhered films. This is achieved by forming an electrodeposition on the entire surface or a part of the metal substrate, and bonding the metal substrates by thermocompression bonding using the electrodeposition film as an adhesive medium. That is, by using the electrodeposition film as an adhesive medium, the adhesive medium can be made thinner, and deformation of the metal base can be avoided during bonding. In addition, since the adhesive medium is formed by electrodeposition, even if the metal substrate is a single-sheet body or a continuous body, the formation can be relatively easily performed. Even when the metal substrate is a continuous body, the electrodeposition can be continuously performed. It is. In addition, since the electrodeposited film serving as an adhesive medium is formed by electrodeposition on the surface portion regardless of the processed shape, it is possible to cope with a case where the metal substrate to be bonded is finely processed. In addition, as the metal substrate on which the fine processing of the object to be bonded is performed,
Lead frames, shadow masks, HDD suspensions, thin metal plates for printer nozzles, etc.
It is not limited to this. Further, the electrodeposition film, which is an adhesive medium, also serves as a film for a metal substrate, and thus prevents metal corrosion.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows one embodiment of the bonding method of the present invention.
FIG. 2 is a schematic cross-sectional view showing various bonding modes. In FIG. 1, S110 to S150 indicate processing steps, and in FIG.
0 is a hole, and 111 to 421 are electrodeposition films.

In this example, a metal substrate 1 and a metal substrate 2, each of which is a single sheet, are bonded to each other by using an electrodeposition solution in which an organic solvent-soluble polyimide and a hydrophilic polymer are dispersed in an aqueous solvent. An electrodeposition film is electrodeposited on the entire surface of both metal substrates to be formed, and the formed electrodeposition film is used as an adhesion medium,
The metal substrates are bonded by thermocompression bonding. Less than,
The processing up to bonding will be described in order with reference to FIG. First,
After performing the pretreatment on the metal base 1 and the metal base 2 (S110), an electrodeposition film is formed by electrodeposition on the entire surface of each. The pretreatment is a process for forming an electrodeposited film uniformly and with good adhesion, and is usually performed in the order of alkali degreasing, washing, pickling, washing, and drying (air blowing). (S120) Then,
Each of the metal base 1 and the metal base 2 is immersed in an electrodeposition solution, and subjected to a pre-dip treatment to make the entire surface wet with the electrodeposition solution. Electrodeposition is performed under the conditions (electrodeposition voltage, electrodeposition time, etc.), an electrodeposition film is electrodeposited, a cleaning process is performed, and a drying process is performed.
(S130) As the electrodeposition film, usually, 0.0008 to
A thin film of about 0.0019 mm is formed.

Next, the metal substrate 1 and the metal substrate 2 having the electrodeposited film formed on the surface thereof are dried to increase the elastic modulus of the electrodeposited film and to give an appropriate adhesive force to the electrodeposited film. After performing the treatment, the metal substrate 1 and the metal substrate 2 each having the electrodeposition film formed on the surface thereof are superimposed on each other, and at a predetermined temperature,
Pressure is applied and thermocompression bonding is performed to bond the two. Furthermore,
Thereafter, drying is performed after bonding in order to increase the bonding strength between the metal base 1 and the metal base 2. Thus, the adhesion between the metal base 1 and the metal base 2 is completed. (S150)

As shown in FIG. 2A, two metal substrates 11 and 12 each having electrodeposition films 111 and 121 formed on the entire surface thereof are superposed and adhered. As shown in FIG. 2B, three metal bases 21, 22, and 23 each having electrodeposition films 211, 221, and 231 formed on the entire surface thereof are superposed and bonded. As shown in FIG. 2D, a metal substrate 31 having no electrodeposition film and a metal substrate 32 having an electrodeposition film 321 formed on the entire surface thereof are overlapped and bonded, FIG.
As shown in FIG. 2, there is a form in which two metal bases 41 and 42 each having an electrodeposition film 411 and 421 formed on one entire surface thereof are overlapped and bonded via the electrodeposition films 411 and 421, and the like. It is not limited to these. FIG.
The hole 50 in (d) is formed by combining the recess of the metal base 41 and the recess of the metal base 42.

In this example, an electrodeposition solution in which an organic solvent-soluble polyimide and a hydrophilic polymer are dispersed in an aqueous solvent is used. However, an organic solvent-soluble polyimide and a hydrophilic polymer are mixed in a solution state in an organic solvent. Examples of the method include (i) a method of mixing a separately prepared solution of a polyimide and a solution of a hydrophilic polymer, and (ii) adding one of the polyimide and the hydrophilic polymer to a solution of the other as a solid. And (iii) a method in which both a polyimide and a hydrophilic polymer are added as solids to an organic solvent and mixed and dissolved, and the like, and the method (i) is particularly preferred.

The organic solvent used when mixing the polyimide and the hydrophilic polymer in a solution state is not particularly limited as long as it is inert to the polyimide and the hydrophilic polymer and can dissolve them. Not something,
Examples thereof include aprotic polar solvents, esters, ketones, and phenols used in the synthesis of the polyamic acid or polyimide, and polar solvents used in the synthesis of the hydrophilic polymer. These organic solvents can be used alone or in combination of two or more. In the case of the method (i), the organic solvent used for the polyimide solution and the hydrophilic polymer solution is as follows:
They may be the same or different.

Further, other compounds can be added to the mixed solution obtained by the methods (i) to (iii) according to the purpose.

Compounds that can be added to the mixed solution of the organic solvent-soluble polyimide and the hydrophilic polymer include, for example, epoxidized polybutadiene, bisphenol A type epoxy resin, naphthalene type epoxy resin, fluorene type epoxy resin, biphenyl type Epoxy resin,
Epoxy compounds such as glycidyl ester type epoxy resins; diisocyanate compounds such as tolylene diisocyanate and blocked products thereof; high-density polyethylene, medium-density polyethylene, polypropylene, polycarbonate, polyarylate, aliphatic polyamide, polyamideimide,
Polysulfone, polyether sulfone, polyether ketone, polyphenylene sulfide, (modified) polycarbodiimide, polyetherimide, polyesterimide,
Thermoplastic or thermosetting resins such as modified polyphenylene oxide can be used. These compounds can be used alone or in combination of two or more.

The concentration of the mixed solution of the organic solvent-soluble polyamide and the hydrophilic polymer is preferably 5 to 60% by weight, more preferably 10 to 50% by weight as the total amount of both components.
% By weight.

When mixing the organic solvent-soluble polyimide and the hydrophilic polymer in a solution state, for example, a stirring blade,
Appropriate mixing means such as a ribbon and a screw can be employed. Further, the mixing conditions are such that the rotation speed is typically
10 to 50,000 rpm, preferably 20 to 5,000 rpm
0 rpm.

When mixing the organic solvent-soluble polyimide and the hydrophilic polymer in a solution state, an appropriate amount of a surfactant can be added as necessary. However, when the obtained electrodeposition liquid is used as an insulating material, the amount of the surfactant is preferably reduced as much as possible because the surfactant may also cause a reduction in insulation durability.

Further, the pH of the electrodeposition solution is preferably 4 to
10, more preferably 5 to 9,
Thereby, an aqueous dispersion having particularly excellent storage stability can be obtained.

Such pH adjustment can be performed, for example, by (iv)
A method of adding a required amount of a pH adjuster to a mixed solution of an organic solvent-soluble polyimide and a hydrophilic polymer and then dispersing the mixture in an aqueous medium; (v) a mixed solution of an organic solvent-soluble polyimide and a hydrophilic polymer Is dispersed in an aqueous medium to which a necessary amount of a pH adjuster is added, (vi) a required amount of a pH adjuster is dispersed while dispersing a mixed solution of an organic solvent-soluble polyimide and a hydrophilic polymer in the aqueous medium. Can be carried out, for example, and the method (iv) is particularly preferable. When the pH is adjusted in the method (II), a necessary amount of a pH adjuster may be added to the aqueous medium in advance.

The pH adjuster is not particularly restricted but includes, for example, ammonia, potassium hydroxide,
Organic or inorganic bases such as sodium hydroxide, lithium hydroxide and alkanolamine; and organic or inorganic protic acids such as formic acid, acetic acid, butyric acid, hydrochloric acid and sulfuric acid. These pH adjusters are appropriately used depending on the type of the reactive group (a) in the organic solvent-soluble polyimide or the hydrophilic group or the reactive group (b) in the hydrophilic polymer, or a combination thereof.

Next, when dispersing the mixed solution of the organic solvent-soluble polyimide and the hydrophilic polymer in the aqueous medium, the aqueous solution may be added to the mixed solution, or the mixed solution may be added to the aqueous medium. It may be added, but the latter method is particularly preferred.

In dispersing the mixed solution of the organic solvent-soluble polyimide and the hydrophilic polymer in the aqueous medium, for example, an appropriate mixing means such as a stirring blade, a ribbon, and a screw can be employed. The mixing conditions vary depending on the solid content concentration of the electrodeposition solution, the desired average particle size of the dispersed particles, and the like, but the rotation speed is typically 10 to 50,000 rpm.
pm, preferably 20 to 5,000 rpm.

In preparing the electrodeposition solution, methods for removing an organic solvent or a medium other than water include, for example, distillation,
Ultrafiltration and the like can be mentioned.

The total amount of the aqueous medium used in the electrodeposition liquid is:
It is preferably 10 to 10,000 based on 100 parts by weight of the total of the organic solvent-soluble polyimide and the hydrophilic polymer.
Parts by weight, more preferably 20 to 5,000 parts by weight. The average particle diameter of the particles in the electrodeposition solution is 0.03 to 5
μm, preferably 0.05 to 2 μm. in this case,
When the average particle diameter of the particles is less than 0.03 μm, the viscosity of the aqueous dispersion becomes too high, and when it exceeds 5 μm, the storage stability of the aqueous dispersion decreases, and the particles tend to settle. . This average particle diameter can be measured by a known optical method or an electron microscope.

Further, in producing the electrodeposition solution, the polyimide and the hydrophilic polymer are combined by appropriately combining the reactive group in the organic solvent-soluble polyimide and the reactive group in the hydrophilic polymer. Mix in solution in an organic solvent,
After the reaction, if necessary, while heating, the reaction solution is mixed with an aqueous medium, and at least a part of the organic solvent is optionally removed, whereby the polyimide and the hydrophilic polymer are mutually bonded. By containing the particles having the predetermined average particle diameter in the same particles and dispersing the particles in an aqueous medium, an electrodeposition solution having excellent storage stability as an aqueous dispersion and various physical properties of a cured product is obtained. Can be manufactured.

The synthesis of an organic solvent-soluble polyimide for forming an electrodeposition solution is performed as follows. The method for synthesizing an organic solvent-soluble polyimide is not particularly limited, but, for example, in an organic polar solvent, a tetracarboxylic dianhydride and a diamine compound are mixed and polycondensed to obtain a polyamic acid. Thereafter, a polyimide can be synthesized by subjecting the polyamic acid to a dehydration ring-closing reaction by a heat imidation method or a chemical imidization method. In addition, a polyimide having a block structure can be synthesized by performing polycondensation of a tetracarboxylic dianhydride and a diamine compound in multiple stages.

<Tetracarboxylic dianhydride> The tetracarboxylic dianhydride used in the synthesis of the organic solvent-soluble polyimide is not particularly limited, and examples thereof include butanetetracarboxylic dianhydride, , 2,3,4
-Cyclobutanetetracarboxylic dianhydride, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride Anhydride, 1,3-dichloro-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4
-Cyclobutanetetracarboxylic dianhydride, 1,2,2
3,4-cyclopentanetetracarboxylic dianhydride,
1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3 ', 4,4'-dicyclohexyltetralcarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic dianhydride, , 5,6-Tricarboxynorbornane-2-acetic acid dianhydride, 2,3,4,5-tetrahydrofurantetracarboxylic dianhydride, 1,3
3a, 4,5,9b-Hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,
2-c] -furan-1,3-dione, 1,3,3a,
4,5,9b-Hexahydro-5-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3
a, 4,5,9b-Hexahydro-5-ethyl-5-
(Tetrahydro-2,5-dioxo-3-furanyl)-
Naphtho [1,2-c] -furan-1,3-dione, 1,
3,3a, 4,5,9b-hexahydro-7-methyl-
5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-7-
Ethyl-5- (tetrahydro-2,5-dioxo-3-
Furanyl) -naphtho [1,2-c] -furan-1,3-
Dione, 1,3,3a, 4,5,9b-hexahydro-
8-methyl-5- (tetrahydro-2,5-dioxo-
3-furanyl) -naphtho [1,2-c] -furan-1,
3-dione, 1,3,3a, 4,5,9b-hexahydro-8-ethyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-
1,3-dione, 1,3,3a, 4,5,9b-hexahydro-5,8-dimethyl-5- (tetrahydro-2,
5-dioxo-3-furanyl) -naphtho [1,2-c]
-Furan-1,3-dione, 5- (2,5-dioxotetrahydrofural) -3-methyl-3-cyclohexene-1,2-dicarboxylic dianhydride, bicyclo [2,2,
2] -oct-7-ene-2,3,5,6-tetracarboxylic dianhydride and aliphatic tetracarboxylic dianhydrides such as compounds represented by the following formula (1) or (2) Or an alicyclic tetracarboxylic dianhydride,

[0027]

Embedded image (Wherein, R ¹ represents a divalent organic group having an aromatic ring;
² represents a hydrogen atom or an alkyl group;
² may be the same or different from each other),

[0028]

Embedded image (Wherein, R ³ represents a divalent organic group having an aromatic ring;
⁴ represents a hydrogen atom or an alkyl group;
⁴ may be the same or different from each other); pyromellitic dianhydride, 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride, 3,3', 4,4'-biphenyl sulfone Tetracarboxylic dianhydride, 1,4,5
8-naphthalenetetracarboxylic dianhydride, 2,3
6,7-naphthalenetetracarboxylic dianhydride, 3,
3 ', 4,4'-biphenylethertetracarboxylic dianhydride, 3,3', 4,4'-dimethyldiphenylsilanetetracarboxylic dianhydride, 3,3 ', 4,4'-
Tetraphenylsilanetetracarboxylic dianhydride, 1,
2,3,4-furantetracarboxylic dianhydride, 4,
4'-bis (3,4-dicarboxyphenoxy) diphenyl sulfide dianhydride, 4,4'-bis (3,4-dicarboxyphenoxy) diphenyl sulfone dianhydride,
4,4'-bis (3,4-dicarboxyphenoxy) diphenylpropane dianhydride, 3,3 ', 4,4'-perfluoroisopropylidene diphthalic anhydride, 3,
3 ', 4,4'-biphenyltetracarboxylic dianhydride, bis (phthalic acid) phenylphosphine oxide dianhydride, p-phenylene-bis (triphenylphthalic acid) dianhydride, m-phenylene-bis (tri Phenylphthalic acid) dianhydride, bis (triphenylphthalic acid)
4,4'-diphenyl ether dianhydride, bis (triphenylphthalic acid) -4,4'-diphenylmethane dianhydride, ethylene glycol-bis (anhydrotrimellitate), propylene glycol-bis (anhydrotrimellitate) ), 1,4-butanediol-bis (anhydrotrimellitate), 1,6-hexanediol-bis (anhydrotrimellitate), 1,8-octanediol-bis (anhydrotrimellitate), 2,2-
Aromatic tetracarboxylic dianhydrides such as bis (4-hydroxyphenyl) propane-bis (anhydrotrimellitate) and compounds represented by the following formulas (3) to (6);

[0029]

Embedded image

[0030]

Embedded image

[0031]

Embedded image

[0032]

Embedded image And the like. These tetracarboxylic dianhydrides can be used alone or in combination of two or more.

<Diamine compound> Examples of the diamine compound used in the synthesis of the polyimide soluble in an organic solvent include p-phenylenediamine, m-phenylenediamine, 4,4'-diaminodiphenylmethane, and 4,4'-diamine.
Diaminodiphenylethane, 4,4'-diaminodiphenylsulfide, 4,4'-diaminodiphenylsulfone, 3,3'-dimethyl-4,4'-diaminobiphenyl, 4,4'-diaminobenzanilide, 4,4 ' -Diaminodiphenyl ether, 1,5-diaminonaphthalene, 3,3'-dimethyl-4,4'-diaminobiphenyl, 5-amine-1- (4'-aminophenyl) -1,
3,3-trimethylindane, 6-amino-1- (4 '
-Aminophenyl) -1,3,3-trimethylindane, 3,4'-diaminodiphenyl ether, 3,3 '
-Diaminobenzophenone, 3,4'-diaminobenzophenone, 4,4'-diaminobenzophenone, 2,2
-Bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-
Aminophenyl) hexafluoropropane, 2,2-bis [4- (4-aminophenoxy) phenyl] sulfone, 1,4-bis (4-aminophenoxy) benzene,
1,3-bis (4-aminophenoxy) benzene, 1,
3-bis (3-aminophenoxy) benzene, 9,9-
Bis (4-aminophenyl) -10-hydroanthracene, 2,7-diaminofluorene, 9,9-bis (4-
Aminophenyl) fluorene, 4,4'-methylene-bis (2-chloroaniline), 2,2 ', 5,5'-tetrachloro-4,4'-diaminobiphenyl, 2,2'-
Dichloro-4,4'-diamino-5,5'-dimethoxybiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 4,4 '-(p-phenyleneisopropylidene) bisaniline, 4,4' -(M-phenyleneisopropylidene) bisaniline, 2,2'-bis [4-
(4-amino-2-trifluoromethylphenoxy) phenyl] hexafluoropropane, 4,4'-diamino-2,2'-bis (trifluoromethyl) biphenyl,
Aromatic diamines such as 4,4'-bis [(4-amino-2-trifluoromethyl) phenoxy] -octafluorobiphenyl; 1,1-metaxylylenediamine;
3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, 4,4-diaminoheptamethylenediamine, 1,4-diaminocyclohexane, isophoronediamine, tetrahydrodiamine Fats such as cyclopentadienylenediamine, hexahydro-4,7-methanoindanylene dimethylenediamine, tricyclo [6,2,1,02.7] -undesylenedimethyldiamine, and 4,4'-methylenebis (cyclohexylamine) Aliphatic diamines or alicyclic diamines; 2,3-diaminopyridine, 2,6
-Diaminopyridine, 3,4-diaminopyridine, 2,
4-diaminopyrimidine, 5,6-diamino-2,3-
Dicyanopyrazine, 5,6-diamino-2,4-dihydroxypyrimidine, 2,4-diamino-6-dimethylamino-1,3,5-triazine, 1,4-bis (3-aminopropyl) piperazine, 2, 4-diamino-6-isopropoxy-1,3,5-triazine, 2,4-diamino-6-methoxy-1,3,5-triazine, 2,4
-Diamino-6-phenyl-1,3,5-triazine,
2,4-diamino-6-methyl-1,3,5-triazine, 2,4-diamino-1,3,5-triazine, 4,
6-diamino-2-vinyl-1,3,5-triazine,
2,4-diamino-5-phenylthiazole, 2,6-
Diaminopurine, 5,6-diamino-1,3-dimethyluracil, 3,5-diamino-1,2,4-triazole, 6,9-diamino-2-ethoxyacridine lactate, 3,8-diamino-6 Such as phenylphenanthridine, 1,4-diaminopiperazine, 3,6-diaminoacridine, bis (4-aminophenyl) phenylamine, and a compound represented by the following formula (7) or (8):
Diamines having two primary amino groups and a nitrogen atom other than the primary amino group in the molecule,

[0034]

Embedded image (Wherein R ⁵ is pyridine, pyrimidine, triazine,
X represents a monovalent organic group derived from a compound having a nitrogen-containing ring structure selected from the group consisting of piperidine and piperazine;
Represents a divalent organic group),

[0035]

Embedded image (Wherein R ⁶ is pyridine, pyrimidine, triazine,
X represents a divalent organic group derived from a compound having a nitrogen-containing ring structure selected from the group consisting of piperidine and piperazine;
Represents a divalent organic group, and a plurality of Xs may be mutually the same or different; monosubstituted phenylenediamines represented by the following formula (9):

[0036]

Embedded image (Wherein Y is -O-, -COO-, -OCO-, -NH
R ⁷ represents a hydrogen atom, a fluorine atom, a trifluoromethyl group, a carbon number of 6
An alkyl group or a monovalent group having a steroid skeleton); diaminoorganosiloxane represented by the following formula (10):

[0037]

Embedded image (Wherein, R ⁸ represents a hydrocarbon group having 1 to 12 carbon atoms, and a plurality of R ⁸ may be the same or different from each other;
p is an integer of 1 to 3, q is an integer of 1 to 20); compounds represented by the following formulas (11) to (23);

[0038]

Embedded image

[0039]

Embedded image

[0040]

Embedded image

[0041]

Embedded image (Where y is an integer of 2 to 12)

[0042]

Embedded image (In the formula, z is an integer of 1 to 5.)

[0043]

Embedded image

[0044]

Embedded image

[0045]

Embedded image

[0046]

Embedded image

[0047]

Embedded image

[0048]

Embedded image

[0049]

Embedded image

[0050]

Embedded image And the like. These diamine compounds are:
They can be used alone or in combination of two or more.

The following are examples of the hydrophilic polymer for the electrodeposition liquid. The hydrophilic polymer component has, as a hydrophilic group, at least one kind of, for example, an amino group, a carboxyl group, a hydroxyl group, a sulfonic group, an amide group, and the like. 0
1 g / 100 g or more, preferably 0.05 g / 100 g
It is composed of the above hydrophilic polymer.

Further, in addition to the above-mentioned hydrophilic group, the hydrophilic polymer includes a carboxyl group, an amino group, a hydroxyl group, a sulfonic acid group, an amide group, and the like in the organic solvent-soluble polyimide.
One reactive group (a) such as an epoxy group or an isocyanate group
Although it may have at least one kind, it is preferable to have at least one kind of reactive group (b) that can react with the reactive group (a).
Examples of such a reactive group (b) include, in addition to an epoxy group, an isocyanate group, and a carboxyl group, an amino group, a hydroxyl group, a sulfonic acid group, and an amide group similar to the hydrophilic groups.

It is considered that such a hydrophilic polymer exhibits an action of dispersing the particles in an aqueous medium in a stable state when mixed in the same particles together with the organic solvent-soluble polyimide.

Preferred among the hydrophilic polymers are homopolymers of a monovinyl monomer having a hydrophilic group (hereinafter referred to as “hydrophilic monomer”), or a hydrophilic monomer unit, typically. Is 0.1 to 80% by weight, preferably 1
Copolymers containing from 60 to 60% by weight, more preferably from 3 to 50% by weight are desirable, and copolymers of hydrophilic monomers are particularly desirable.

Further, a preferred hydrophilic polymer is a reactive group (b) capable of reacting with the reactive group (a).
Is typically 0.1 to 30% by weight, preferably 0.2 to 20% by weight, and more preferably 0.1 to 30% by weight. 5-
A copolymer containing 15% by weight is desirable.

<Hydrophilic monomer or reactive monomer constituting hydrophilic polymer> Among the hydrophilic monomers or reactive monomers constituting the hydrophilic polymer, amino group-containing monomers are used. Is an aminoalkyl group-containing (meth) such as 2-dimethylaminoethyl (meth) acrylate, 2-diethylaminoethyl (meth) acrylate, 2-dimethylaminopropyl (meth) acrylate, and 3-dimethylaminopropyl (meth) acrylate. ) Acrylates; 2- (2-dimethylaminoethoxy) ethyl (meth) acrylate, 2- (2-diethylaminoethoxy) ethyl (meth) acrylate, 2- (2-dimethylaminoethoxy) propyl (meth) acrylate, 3- Amines such as (2-dimethylaminoethoxy) propyl (meth) acrylate Alkoxyalkyl group-containing (meth) acrylates; N- (2-dimethylaminoethyl) (meth) acrylamide, N- (2-diethylaminoethyl) (meth) acrylamide, N- (2-dimethylaminopropyl) (meth) acrylamide , N-
N-aminoalkyl group-containing (meth) acrylamides such as (3-dimethylaminopropyl) (meth) acrylamide; p-dimethylaminomethylstyrene, p-diethylaminomethylstyrene, p-dimethylaminomethyl-
α-methylstyrene, p-diethylaminomethyl-α-
Methylstyrene, p- (2-dimethylaminoethyl) styrene, p- (2-diethylaminoethyl) styrene,
Amino group-containing aromatic vinyl compounds such as p- (2-dimethylaminoethyl) -α-methylstyrene, p- (2-diethylaminoethyl) -α-methylstyrene, 2-vinylpyrine and 4-vinylpyrine; glycidyl (meth) Examples include adducts of an acrylate with a primary or secondary amine compound, and salts obtained by neutralizing or quaternizing amino groups in these monomers.

Among the hydrophilic monomers or reactive monomers constituting the hydrophilic polymer, examples of the carboxyl group-containing monomer include (meth) acrylic acid, crotonic acid, cinnamic acid, and maleic acid. Carboxyl groups of unsaturated polycarboxylic acids such as monomethyl maleate, monoethyl maleate, monomethyl fumarate, monoethyl fumarate, etc .; Esters and salts thereof; succinic acid mono (2- (meth) acryloyloxyethyl) ester, phthalic acid mono (2
Mono (2- (meth) acryloyloxyalkyl) esters of non-polymerizable dicarboxylic acids such as-(meth) acryloyloxyethyl) ester and salts thereof can be mentioned.

Among the hydrophilic monomers or reactive monomers constituting the hydrophilic polymer, examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth). Acrylate,
3-hydroxypropyl (meth) acrylate, N-methylol (meth) acrylamide, 2- (meth) acryloyloxyethyl phthalate, 2-hydroxyethyl diester, etc., and a sulfonic acid group-containing vinyl monomer Examples thereof include p-styrenesulfonic acid, p-α-methylstyrenesulfonic acid, sulfonated isoprene, and salts thereof. Examples of the amide group-containing monomer include (meth) acrylamide, Crotonic amide, cinnamic amide, maleic diamide, fumaric diamide and the like.

Among the reactive monomers constituting the hydrophilic polymer, examples of the epoxy group-containing monomer include glycidyl (meth) acrylate, allyl glycidyl ether and 3,4-epoxycyclohexyl (meth).
Acrylate and the like can be mentioned.

Among the reactive monomers constituting the hydrophilic polymer, examples of the isocyanate group-containing monomer include 2-isocyanatoethyl (meth) acrylate,
-Isocyanatopropyl (meth) acrylate, 3-isocyanatopropyl (meth) acrylate and the like.

These hydrophilic monomers and reactive monomers can be used alone or in combination of two or more.

<Other Copolymerizable Monomers> Examples of other monovinyl monomers copolymerizable with the hydrophilic monomer or the reactive monomer constituting the hydrophilic polymer include, for example, methyl (Meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, i-propyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate, se
c-butyl (meth) acrylate, t-butyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl (meth) (Cyclo) alkyl (meth) acrylates such as acrylate; 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2-methoxypropyl (meth) acrylate, 3-methoxypropyl (meth) acrylate, 2 Alkoxy (cyclo) alkyl (meth) acrylates such as -methoxybutyl (meth) acrylate, 3-methoxybutyl (meth) acrylate, 4-methoxybutyl (meth) acrylate, p-methoxycyclohexyl (meth) acrylate Cyano group-containing monomers such as (meth) acrylonitrile, vinylidene cyanide, crotonitrile, 2-cyanoethyl (meth) acrylate, 2-cyanopropyl (meth) acrylate, and 3-cyanopropyl (meth) acrylate; Methoxymethyl (meth) acrylamide, N-ethoxymethyl (meth) acrylamide, N- (2-methoxyethyl) (meth) acrylamide, N- (3-methoxypropyl)
(Meth) acrylamide, N- (4-methoxybutyl)
N-alkoxyalkyl-substituted derivatives of the amide group-containing monomer such as (meth) acrylamide; trifluoroethyl (meth) acrylate, pentafluoropropyl (meth) acrylate, heptafluorobutyl (meth)
Fluoroalkyl (meth) acrylates such as acrylate; trimethylsiloxanyldimethylsilylpropyl (meth) acrylate, tris (trimethylsiloxanyl) silylpropyl (meth) acrylate, di (meth) acrylate
Siloxanyl compounds such as acryloylpropyldimethylsilyl ether; styrene, o-vinyltoluene, m
Monovinyl aromatic compounds such as vinyltoluene, p-vinyltoluene, p-ethylstyrene, α-methylstyrene and α-fluorostyrene; halogenated vinyl compounds such as vinyl chloride and vinylidene chloride; vinyl acetate, vinyl propionate and the like Vinyl esters: In addition to unsaturated aliphatic hydrocarbons such as ethylene, butadiene, and isoprene, silicon-modified monomers, macromonomers, and the like can be given. The other monovinyl monomer may be used alone or
A mixture of more than one species can be used.

Further, the amount of the obtained copolymer may be, for example, divinylbenzene or the like in an amount that does not excessively impair the hydrophilicity of the copolymer.
Polyvinyl aromatic compounds such as diisopropenylbenzene; bis (meth) acrylamides such as ethylenebis (meth) acrylamide, trimethylenebis (meth) acrylamide, and tetramethylenebis (meth) acrylamide; ethylene glycol di (meth) acrylate; Diethylene glycol di (meth) acrylate, polyethylene glycol diacrylate, propylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, 1 1,4-butylene glycol di (meth) acrylate, 1,6-hexylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 2, 2-bis (4- (meth) acryloxypropoxyphenyl) propane, 2,2-
Bis (4- (meth) acryloxydiethoxyphenyl)
Di (meth) acrylates such as propane; glycerin tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolethanetri (meth) acrylate, pentaerythritol tetra (meth) acrylate, di-trimethylolpropane tetraacrylate One or more crosslinkable monomers such as a monomer having three or more (meth) acryloxy groups can also be copolymerized.

<Synthesis of Hydrophilic Polymer> The hydrophilic polymer can be produced, for example, by a known solution polymerization using a radical polymerization initiator and, if necessary, in the presence of a chain transfer agent. Examples of the polymerization medium used for the solution polymerization include water, a polar solvent, a mixed medium of water and a polar solvent, and the like. Examples of the polar solvent include acetonitrile, N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, tetramethylurea, hexamethylphosphortriamide, and acetic acid. Methyl, ethyl acetate, n-propyl acetate,
N-butyl acetate, methyl 3-methoxypropionate, 3
-Methyl ethoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, diethyl oxalate, diethyl malonate, ethyl lactate, butyl lactate, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, ethylene glycol, 1,
3-propylene glycol, 1,4-butylene glycol, diethylene glycol, triethylene glycol,
Polyethylene glycol 200, polyethylene glycol 400, polyethylene glycol 600, polyethylene glycol 1500, glycerin, N-methylolpyrrolidone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol mono-n-butyl ether , Diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol diether, methanol,
Ethanol and the like can be mentioned. These polar solvents can be used alone or in combination of two or more.

The hydrophilic polymer is preferably a known hydrophilic polymer which satisfies the above-mentioned solubility condition in water, for example, polyvinylpyrrolidone, polyethyleneimine, polyallylamine, sulfonated polystyrene, sulfonated styrene-isoprene copolymer Compounds and the like can also be used.

The number average molecular weight (hereinafter referred to as “Mn”) of the hydrophilic polymer determined by gel permeation chromatography (GPC) is typically 1,000 to 1
00,000, preferably 3,000 to 20,000.

The hydrophilic polymers can be used alone or in combination of two or more.

The hydrophilic polymer is used for preparing an electrodeposition solution as a solution or a solid.

<Additives> Various additives can be added to the electrodeposition solution as needed. Such additives include, for example, epoxidized polybutadiene, bisphenol A epoxy resin, naphthalene epoxy resin,
Epoxy compounds such as fluorene-based epoxy resins, biphenyl-type epoxy resins and glycidyl ester-type epoxy resins; diisocyanate compounds such as tolylene diisocyanate and their blocked products; high-density polyethylene, medium-density polyethylene, polypropylene, polycarbonate,
Thermoplastic or thermosetting resins such as polyarylate, aliphatic polyamide, polyamideimide, polysulfone, polyethersulfone, polyetherketone, polyphenylene sulfide, (modified) polycarbodiimide, polyetherimide, polyesterimide, modified polyphenylene oxide, etc. Can be mentioned.

Other additives include, for example, fillers such as clay, zeolite, talc, mica, silica, carbon black, graphite, alumina, calcium carbonate, wollastonite, glass, carbon, alumina and titanium. Fibers such as potassium silicate, aluminum borate, silicon carbide, silicon nitride, aromatic polyamide, polyamide imide, polyimide, wholly aromatic polyester, ultra-high molecular weight polyethylene, high-strength polyacrylonitrile, high-strength polyvinyl alcohol, and reinforcing materials such as whiskers Can be mentioned. The reinforcing material may be used, for example, in the form of a fabric such as a woven fabric, a nonwoven fabric, or a knitted fabric, and may be used by impregnating the fabric with the electrodeposition film forming solution for transfer of the present invention.

Each of the above additives can be used alone or in combination.
A mixture of more than one species can be used.

Further, additives other than those described above include, for example, antioxidants, heat stabilizers, ultraviolet absorbers, light stabilizers,
Examples thereof include an antistatic agent, a flame retardant, a coloring agent, a lubricant, an antifogging agent, an adhesion improving agent, and a fungicide.

If necessary, a small amount of an emulsifier or a water-soluble dispersant can be added to the electrodeposition film forming liquid for transfer.

[0074]

(Example 1) In Example 1, a metal substrate 1 and a metal substrate 2, each of which is a single thin plate, were formed by using the bonding method of the embodiment shown in FIG.
Adhesion was performed using a 40% square, 0.1 mm thick 42% Ni-Fe alloy (referred to as 42 alloy) as a solid plate, and using the electrodeposition liquid 1 obtained in Adjustment Example 1 described later. Things. It will be described below in order based on FIG.
First, the pretreatment (S12) is performed on the metal base 1 and the metal base 2.
As 0), alkali degreasing-washing-pickling-washing-drying (air blower) was performed, respectively. (S121-
S125) Next, in order to increase the wettability of the surface portion before the electrodeposition and to prevent the occurrence of pinholes due to partial electrodeposition inhibition due to bubbles during the electrodeposition, the same electrodeposition liquid 1 as the electrodeposition liquid 1 is used. Prior to film formation, pre-dip was performed. (S131) Next, electrodeposition was performed under the following electrodeposition conditions to obtain a 0.012 mm
A thick electrodeposited film thickness was obtained. (S132) <Electrodeposition condition> Applied voltage 6V Electrodeposition time 60 seconds Next, cleaning was performed (S133), and further, in an oven,
A drying treatment was performed at 100 ° C. for 5 minutes. (S134) Next, in order to increase the modulus of elasticity and give a suitable adhesive strength,
After drying before press bonding at 00 ° C. for 2 minutes (S141),
The metal substrate 1 on which the electrodeposition film is formed and the metal substrate 2 are overlapped, and the press plate temperature is 250 ° C., the press pressure is 50 kg / c.
Thermocompression bonding was performed at m ^{2 for} a pressing time of 35 sec. (S142) Further, in order to increase the bonding strength, 150
C. and dried for 1 hour. (S143) Thus, the metal base 1 and the metal base 2 were bonded. The adhered product was placed in a 3% sulfuric acid aqueous solution (room temperature) for 1 hour.
After soaking for weeks, no corrosion was observed.

(Example 2) In Example 2, bonding was performed using the electrodeposition liquid 2 obtained in Adjustment Example 2 described later in Example 1. Also in the case of this example, the bonded product was immersed in a 3% sulfuric acid aqueous solution (normal temperature) for one week.
No corrosion was seen.

Example 3 In Example 3, bonding was performed using the electrodeposition liquid 3 obtained in Adjustment Example 3 described later in Example 1. Also in the case of this example, the bonded product was immersed in a 3% sulfuric acid aqueous solution (normal temperature) for one week.
No corrosion was seen.

(Preparation Example 1) 50 parts (solid content) of the polyimide (A-2) obtained in Synthesis Example 2 of the polyimide described later were mixed with the hydrophilic polymer obtained in Synthesis Example 1 of the hydrophilic polymer described later ( 30 parts (solid content) of B-1) and 20 parts (solid content) of Epicoat YL980 (manufactured by Yuka Shell Epoxy) as an additive were thoroughly mixed, heated at 70 ° C. for 3 hours, and then 3 parts of acetic acid Slowly add and mix, pH
Adjustments were made. Then, 1000 parts of distilled water was gradually added to obtain an electrodeposition film forming liquid free of aggregates (this is referred to as electrodeposition liquid 1). (Adjustment Example 2) 50 parts (solid content) of the polyimide (A-3) obtained in Synthesis Example 3 of the polyimide described later, and the hydrophilic polymer (B-1) obtained in Synthesis Example 1 of the hydrophilic polymer described later ) Of 30 parts (solid content) and 2 parts of Epicoat YX4000H (manufactured by Yuka Shell Epoxy) as an additive.
An electrodeposition film forming liquid (hereinafter referred to as electrodeposition liquid 2) was obtained in the same manner as in Preparation Example 1 except that 0 part (solid content) was used. (Adjustment Example 3) 30 parts (solid content) of the polyimide (A-1) obtained in the polyimide synthesis example 1 described later were mixed with the hydrophilic polymer (B-B) obtained in the hydrophilic polymer synthesis example 2 described later.
2) 40 parts (solid content), Epicoat Y as an additive
30 parts of L980 (made of Yuka Shell Epoxy) (solid content)
Was used in the same manner as in Preparation Example 1, except that was used, to obtain an electrodeposition film forming liquid (hereinafter referred to as electrodeposition liquid 3).

(Synthesis Example 1 of Polyimide) As a tetracarboxylic dianhydride, 17.94 g (50 mmol) of 3,3 ′, 4,4′-diphenylsulfonetetracarboxylic dianhydride, 4,4 ′-[ 2,2,2-trifluoromethyl-1- (trifluoromethyl) ethylidene] bis (1,2-benzenedicarboxylic anhydride 17.78 g
(40 mmol) and 1, 3, 3a, 4, 5, 9b-
Hexahydro-5 (tetrahydro-2,5-dioxo-
3-furanyl) -naphtho [1,2-c] -furan-1,
3.00 g (10 mmol) of 3-dione, 36.95 g (90 mmol) of 2,2-bis [4- (4-aminophenoxy) phenyl] propane as a diamine compound
And an organosiloxane LP71 corresponding to the formula (1)
2.49 g (10 mmol) of 00 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.) was dissolved in 450 g of N-methyl-2-pyrrolidone and reacted at room temperature for 12 hours. Thereafter, to this reaction solution, 32 g of pyridine and 71 g of acetic anhydride were added, and 1
The dehydration ring closure reaction was performed at 00 ° C. for 3 hours. Then, the reaction solution was purified by distillation under reduced pressure, and the logarithmic viscosity was 0.51 dl /.
g, a solution of polyimide (hereinafter referred to as A-1) having an imidation ratio of 95% and a solid content of 10% containing 5% polyamic acid was obtained. (Synthesis example 2 of polyimide) 35.88 g (100 mmol) of 3,3 ′, 4,4′-diphenylsulfonetetracarboxylic dianhydride as tetracarboxylic dianhydride,
32.84 g of 2,2-bis [4- (4-aminophenoxy) phenyl] propane as a diamine compound (80
Mmol) 4,4'-diaminodiphenylmethane
98 g (10 mmol) and 9.00 g (10 mmol) of an organosiloxane X-22-161AS (trade name, manufactured by Shin-Etsu Chemical Co.) corresponding to the formula (1) were added to N-methyl-2.
-Dissolved in 500 g of pyrrolidone and reacted at room temperature for 12 hours. Thereafter, 32 g of pyridine and 71 g of acetic anhydride were added to this reaction solution, and a dehydration ring closure reaction was performed at 100 ° C. for 3 hours. Next, the reaction solution was purified by distillation under reduced pressure, and had a logarithmic viscosity of 0.45 dl / g and an imidation ratio of 95%.
A solution of 10% solid content polyimide (hereinafter referred to as A-2) containing 5% polyamic acid was obtained. (Synthesis example 3 of polyimide) 17.94 g (50 mmol) of 3,3 ′, 4,4′-diphenylsulfonetetracarboxylic dianhydride and 3,3 ′, 4,4 ′ as tetracarboxylic dianhydrides -Benzophenonetetracarboxylic dianhydride 16.11 (50 mmol), 2,2-bis [4- (4-aminophenoxy) as a diamine compound
[Phenyl] propane 28.74 g (70 mmol), diaminobenzoic acid 3.04 g (20 mmol) and an organosiloxane X-22 corresponding to the above formula (10).
9.00 g (10 mmol) of 161AS (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.) was dissolved in 500 g of N-methyl-2-pyrrolidone and reacted at room temperature for 12 hours. Thereafter, 8 g of pyridine and 10 g of acetic anhydride were added to the reaction solution,
The dehydration ring closure reaction was performed at 100 ° C. for 3 hours. Next, the reaction solution was purified by distillation under reduced pressure, and a logarithmic viscosity of 0.48 dl /
g, a solution of polyimide (hereinafter referred to as A-3) having an imidation ratio of 50% and a solid content of 10% containing polyamic acid of 50% was obtained.

(Synthesis Example 1 of Hydrophilic Polymer) A reaction vessel containing 100 parts of γ-butyrolactone was kept at 85 ° C. under a nitrogen gas atmosphere, and 65 parts of n-butyl acrylate, dimethylaminoethyl Acrylate 3
While continuously adding a mixed solution consisting of 0 parts, 5 parts of glycidyl methacrylate, and 1 part of azobisisobutyronitrile over 5 hours, solution polymerization was performed under stirring.
After completion of the dropwise addition, stirring was further continued at 85 ° C. for 2 hours to complete the solution polymerization, and a hydrophilic polymer having a solid content of 50% (hereinafter referred to as B-1) was obtained. (Synthesis example 2 of hydrophilic polymer) γ-butyrolactone 10
The reactor containing 0 parts was kept at 85 ° C. under a nitrogen gas atmosphere, and n-butyl acrylate 65 was added to the reactor.
, A mixture of 30 parts of dimethylaminoethyl acrylate, 5 parts of isocyanatoethyl methacrylate, and 1 part of azobisisobutyronitrile was added continuously over 5 hours to carry out solution polymerization under stirring. . After completion of the dropping, stirring was continued at 85 ° C. for another 2 hours to complete the solution polymerization, and a hydrophilic polymer having a solid content of 50% (B
-2).

[0080]

As described above, the present invention relates to a method of bonding metal substrates each other in which the metal substrate is a thin plate. It is possible to provide a bonding method that can bond without any problem. In addition, it has become possible to provide a bonding method that can be used in mass production.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a flow of an example of an embodiment of a bonding method of the present invention.

FIG. 2 is a cross-sectional view showing various types of bonding.

[Explanation of symbols]

 S110-S150 Processing Steps 11-44 Metal Base 50 Holes 111-421 Electrodeposited Film

Continued on the front page (72) Inventor Hiroto Yoshinuma 1-1-1, Ichigaya-Kaga-cho, Shinjuku-ku, Tokyo Inside Dai Nippon Printing Co., Ltd. (72) Inventor Yoichi Hitomi 1-1-1-1, Ichigaya-ka-cho, Shinjuku-ku, Tokyo No. Within Dai Nippon Printing Co., Ltd. (72) Inventor Kazuo Umeda 1-1-1, Ichigaya Kagacho, Shinjuku-ku, Tokyo Inside Dainippon Printing Co., Ltd. (72) Junichi Yamada 1-1, Ichigaga-cho, Shinjuku-ku, Tokyo No. 1 Inside Dai Nippon Printing Co., Ltd. (72) Inventor Yuji Yamaguchi 1-1-1, Ichigaya Kagacho, Shinjuku-ku, Tokyo F-term inside Dai Nippon Printing Co., Ltd. 4J040 DB092 DH012 DH022 DH032 EH031 JA02 JA03 MA02 NA20 PA02 PA30 PA33

Claims (3)

[Claims] 1. A method of bonding metal substrates, comprising:
Using an electrodeposition solution in which an organic solvent-soluble polyimide and a hydrophilic polymer are dispersed in an aqueous solvent, an electrodeposition film is formed by electrodeposition on the entire surface or a part of one or both of the metal substrates to be adhered. A bonding method comprising bonding metal substrates together by thermocompression bonding using the film as an adhesive medium. 2. The bonding method according to claim 1, wherein the metal substrate is one selected from a lead frame, a shadow mask, an HDD suspension, and a metal sheet for a printer nozzle. 3. The bonding method according to claim 1, wherein the metal substrate is a single sheet or a continuous body.