JP2903333B2 - Adhesive composition for temporary fixing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an adhesive composition used for temporarily fixing electronic components such as I and C before soldering them on a printed circuit board. In particular, after the temporary fixation, the electronic components do not shift or fall off when soldering, and when the temporarily fixed electronic components are removed for replacement etc., they can be easily immersed only in water or hot water etc. The present invention relates to a temporary fixing adhesive composition that can be quickly removed and can easily remove an adhesive remaining on a printed circuit board.

[Conventional technology]

When soldering electronic components such as I and C onto a printed circuit board, it is necessary to temporarily fix the electronic components before soldering in order to prevent the electronic components from shifting or falling off.

Conventionally, a cyanoacrylate-based adhesive has been used as an adhesive for such temporary fixing.

[Problems to be solved by the invention]

However, this adhesive causes the adhesive to flow out of the gap between the electronic component and the printed circuit board, resulting in insufficient temporary fixation, causing the electronic component to shift or fall off during soldering, making soldering difficult. Becomes

Further, when the electronic component is temporarily fixed on the printed circuit board and then replaced for repair or the like, the electronic component must be removed from the printed circuit board.
However, this removal requires heating at a temperature of 150 ° C for several tens of minutes, which not only makes the removal work troublesome, but also deteriorates the electronic components due to this heat,
Receives damages and other losses. In addition, even after the electronic components have been removed, the adhesive remaining on the printed circuit board must be removed by washing with an organic solvent, which makes the removal work cumbersome. It will introduce the deterioration of the working environment due to the solvent.

Therefore, an object of the present invention is to temporarily fix an electronic component on a printed circuit board, and to prevent the electronic component from shifting or falling off during soldering, and to replace the temporarily fixed electronic component from the printed circuit board for replacement. It can be easily and quickly removed by simply immersing it in water or warm water when removing it, and the residual adhesive on the printed circuit board is also removed by washing, and the temporary fixing adhesive that has improved the disadvantages of the above-mentioned known technology is improved. Agent composition.

[Means for solving the problem]

In order to achieve the above object, according to the present invention, in an adhesive composition used as a temporary fixing of an electronic component before soldering the electronic component on a printer substrate, the following (A), (B) ), (C) and (D), that is, (A) a monomer having at least one ethylenic double bond in the molecule and whose homopolymer can be water-absorbing or water-soluble (B) water-absorbing or water-soluble (C) a monomer having at least one ethylenic double bond in the molecule, and a homopolymer thereof being non-water-absorbing and non-water-soluble; (D) a polymerization initiator; ) And (B) are used in an amount of 0.1 to 25 parts by weight with respect to 100 parts by weight,
(D) is used in an amount of 0.01 to 10 parts by weight, and according to the present invention, the above-mentioned component (A),
In addition to (B), (C) and (D), an inorganic filler is contained as component (E).

Specific examples of the above-mentioned component (A) include N-vinyl-2-pyrrolidone, N, N-dialkylaminoalkyl (meth) acrylic acid, such as N, N-dimethylaminoethyl acrylate, and N, N-dialkyl. Amino (meth) acrylamides such as N, N-diacrylamide, N-N-dialkylaminoalkyl (meth) acrylamides such as N, N-dimethylaminopropylacrylamide, N-N-dimethylamino And propyl methacrylamide.

As the component (B), besides a homopolymer of the monomer of the component (A) or a copolymer of a different monomer of the component (A), for example, polyethylene glycol, polyethylene oxide, alginic acid, a salt of alginic acid, carboxymethylcellulose, hydroxy Ethylcellulose, methylcellulose, methylcellulose, ethylcellulose, poly (meth) acrylic acid, poly (meth) acrylic acid salt,
Polyvinyl alcohol, polyvinyl ether, polyethyloxazoline, vinylpyrrolidone-vinyl acetate copolymer, methyl vinyl ether-maleic anhydride copolymer,
Examples include starch, gelatin, agar and the like. These components (B) are preferably dissolved in the component (A), but may be completely or partially insoluble and dispersed in the component (A). In addition, the component (B) may be any substance having any of the properties of water absorption and water solubility.

Specific examples of the component (C) include, for example, isobornyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, 1,6- Hexanediol di (meth) acrylate, pentaerythritol tri (meth) acrylate, tris [-2- (meth) allyloxyethyl] isocynurate, dipentaerythritol monohydroxypenta (meth) acrylate, bisphenol A ethoxy (meth) acrylate, etc. Is raised.

Further, as the component (D), for example, a photopolymerization initiator,
Redox polymerization initiators and the like, and specific examples of the photopolymerization initiator include, for example, benzophenone, acetophenone, Michler's ketone, benzyl, benzoin,
Benzoin methyl ether, benzoin ethyl ether, tetramethyl thiuram sulfide, thioxane trichlorothioxanthone, benzyl dimethyl ketal, methyl benzoyl formate, and the like.In addition to these photopolymerization initiators, if necessary, use a sensitizer. You can also. The redox polymerization initiator is a redox catalyst containing an organic peroxide and a reducing agent, for example, methyl ethyl ketone peroxide, ketone peroxide such as methylcyclohexanone peroxide and a metal soap such as cobalt naphthenate and copper naphthenate. combination,
Or a combination of a diacyl peroxide such as octanoyl peroxide or benzoyl peroxide with a tertiary amine such as N, N-dimethylaniline, N, N-dimethyl-P-toluidine, or cumene hydroperoxide or diisopropylbenzene hydro Examples include a combination of a hydroperoxide such as peroxide and an organic thiourea such as thiourea and ethylene thiourea. As the component (D), a photopolymerization initiator and a redox-based polymerization initiator can be used in combination.

The mixing ratio of the components (A) and (B) is arbitrary, but if the viscosity is to be increased, a large amount of the component (B) is mixed. The viscosity is adjusted to a desired value by changing the amount of (1).

The amount of the component (C) added is 0.1 to 25 parts by weight, preferably 5 to 15 parts by weight, based on 100 parts by weight of the total of the components (A) and (B). If the amount is too small, the electronic components will shift or fall off during soldering. If the amount is too large, the water solubility of the cured product will decrease, and the workability when removing the electronic components will decrease.

The amount of the component (D) is 0.01 to 10 parts by weight, preferably 1 to 5 parts by weight, based on 100 parts by weight of the total of the components (A) and (B).

In the present invention, in addition to the components (A), (B), (C) and (D), the viscosity of the adhesive composition can be more easily adjusted by further containing an inorganic filler. In addition, thixotropic properties can be imparted to the adhesive composition, and workability in handling the adhesive can be improved. As such an inorganic filler, a filler dispersed in water such as a silica-based filler is preferable, and a filler in which a hydroxyl group on the surface of a filler particle remains is more preferable. There is no limitation.

Further, the present invention, if necessary, a polymerization inhibitor, for example,
Hydroquinone, catechol, 2,6-ditert-butyl-P-cresol and the like can be used for the purpose of improving storage stability.

[Action]

The above-mentioned composition of the present invention comprises the component (B) relative to the component (A).
The viscosity can be freely adjusted by changing the blending amount of the resin, so that, for example, even if the electronic component is warped and a large gap is formed between the electronic component and the printed circuit board, the viscosity is adjusted to be high to adjust the viscosity. , And does not flow out of the gap unlike the conventional cyanoacrylate adhesive, and the temporary fixing is sufficient to prevent the electronic components from shifting or falling off. Further components (A), (B), (C)
Increases the adhesive strength of the temporary fixing, prevents the electronic components from slipping or falling off during soldering, increases the water absorption or water solubility of the cured product, and improves workability when removing the electronic components I do.

Further, by adding an inorganic filler to the composition of the present invention, the above viscosity adjustment is further facilitated, and the thixotropic property can be imparted to the adhesive composition of the present invention, so that workability in handling is improved.

(Example of the invention)

Adhesive composition samples No. 1 to 5 having the formulations shown in Table 1 below
Were mixed and adjusted. Among them, Sample Nos. 1 and 2 are compositions according to the present invention (Examples), Samples Nos. 3 to 5 are comparative examples, and particularly Sample No. 5 is a conventional ethyl cyanoacrylate adhesive alone. .

A temporary fixing test as shown in FIG. 1 and FIG. 2 was performed using each sample adhesive in Table 1.

FIG. 1 is a plan view showing a state in which an electronic component is temporarily fixed to a printed circuit board, and FIG. 2 is a cross-sectional view of FIG. First
As shown in FIG. 2 and FIG. 2, the adhesives 2 of the respective sample Nos. 1 to 5 in Table 1 were applied on the printed circuit board 1, respectively.
The electronic component 3 was mounted thereon. Next, each of the sample Nos. 1 to 4 was irradiated with ultraviolet rays from a height of 15 cm for 20 seconds using a high-pressure mercury lamp (4 KW) to temporarily fix the electronic component 3 on the printed circuit board 1. For sample No.5, humidity 60%, temperature 25 ℃
Was temporarily fixed by being left for 24 hours under the conditions described above.

Each of the above-mentioned samples was tested for solder heat resistance and removability in water. Solder heat resistance test
Each of the above-mentioned temporarily fixed samples was immersed twice in a solder bath at a temperature of 260 ° C. twice for 3 seconds, and the floating and displacement of the electronic component 3 were visually observed. Regarding the removability, each sample was immersed in warm water with stirring at a temperature of 80 ° C., and the peeled state was observed. Table 2 shows the results.

As is clear from Table 2, the samples according to the composition of the present invention
Nos. 1 and 2 show satisfactory values for both the solder heat resistance and the removability.

〔The invention's effect〕

As described above, the adhesive composition of the present invention does not displace or drop electronic components at the time of final joining with solder, and can be easily removed with water, so that improvement in workability when replacing electronic components can be expected. Also, the working environment is good because cleaning with an organic solvent is not required.

[Brief description of the drawings]

FIG. 1 is a plan view showing an attached state of an electronic component, and FIG. 2 is a sectional view of FIG. 1. Printed circuit board 2. Adhesive 3. Electronic parts.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) C09J 4 / 06,4 / 02,4 / 00 H05K 3/34

Claims (3)

(57) [Claims] An adhesive composition used for temporarily fixing an electronic component before soldering the electronic component on a printer substrate comprises the following (A), (B), (C) and (D):
And the amount of (C) used is 0.1 to 25 parts by weight with respect to 100 parts by weight of the total used amount of (A) and (B),
The adhesive composition for temporary fixing, wherein the amount of (D) used is 0.01 to 10 parts by weight. (A) a monomer having at least one ethylenic double bond in the molecule and a homopolymer of which is capable of becoming water-absorbing or water-soluble; (B) a water-absorbing or water-soluble polymer substance; Having at least one hydrophilic double bond and whose homopolymer can be non-water-absorbing and non-water-soluble (D) a polymerization initiator 2. The composition according to claim 1, wherein in addition to the components (A), (B), (C) and (D),
An adhesive composition for temporary fixing, further comprising an inorganic filler as the component (E). 3. The composition according to claim 1, wherein component (C) is isobornyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyloxyethyl. (Meth) acrylate, 1,6-hexanediol di (meth) acrylate, pentaerythritol tri (meth) acrylate, tris [2- (meth) acryloxyethyl] isocyanurate, dipentaerythritol monohydroxypenta (meth) An adhesive composition for temporary fixing, which is one or more compounds selected from acrylate and bisphenol A epoxy (meth) acrylate.