JPS63248883A - Adhesive composition and usage thereof as adhesive - Google Patents

Abstract

PURPOSE:To obtain an adhesive composition suitable for bonding printed circuit boards mutually or between said board and substrate, copper foil, etc., by kneading filler and thixotropic agent in a blend of ultraviolet-curing epoxy resin composition and thermosetting epoxy resin composition. CONSTITUTION:The objective composition can be obtained by kneading a blend comprising (A) a ultraviolet-curing epoxy-methacrylate resin composition and (B) a thermosetting epoxy resin composition either incurable by ultraviolet irradiation or containing a potential curing agent resistant to such curing with (C) filler and (D) a thixotropic agent. This composition has the following characteristics: 1, viscosity at a shear rate 1sec<-1> (at 25 deg.C) 200-500PS (determined using a Brookfield type viscometer) 2, thixotropic index defined as the ratio: viscosity at a shear rate 1sec<-1> determined using a Brookfield type viscometer/viscosity at a shear rate 100sec<-1> determined using said viscometer 10-60.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an adhesive composition used for bonding printed wiring boards to each other or to bonding a printed wiring board to a base material or copper foil, and its adhesive composition. It relates to how to use it as an adhesive.

[Prior Art] Conventionally, adhesive sheets used for bonding such printed wiring boards, etc. are made by impregnating a base material with a thermosetting resin composition mainly composed of epoxy resin, unsaturated polyester resin, etc. Alternatively, it is produced by applying it or forming it into a sheet or film and heating it at an appropriate temperature and time to bring it into a semi-cured state. Then, the prepreg, sheet, or film produced by the above method is thermocompressed (temporarily bonded) to one side of the adherend such as a printed wiring board using a press, etc., and then mechanical processing is performed on the printed wiring board, etc. 1) This was again hot-pressed (main bonding) to the other object to be bonded using a press or the like.

However, the above-mentioned thermosetting adhesive sheet S and its adhesion method had the following drawbacks.

First, in order to bring the resin composition into the desired semi-cured state homogeneously and with good reproducibility, it is necessary to strictly control manufacturing conditions such as heating temperature and heating time. Since the adhesive sheet was in a semi-cured state, the curing reaction of unreacted resin reactive groups proceeded gradually even at room temperature, resulting in extremely poor storage stability of the adhesive sheet.

Furthermore, since the resin composition is a thermosetting resin, it requires a long heating time to reach the desired semi-cured state, resulting in poor productivity. In addition, in order to impregnate or apply the resin composition described in h above to a substrate or to form it into a sheet or film, it is necessary to add a solvent or a diluent to lower the viscosity. In this case, when it was brought into a semi-cured state, the solvent could not be removed sufficiently, causing voids or deteriorating the properties of the product after the #ti was deposited.

In addition to the adhesive strength, the above adhesive sheet also has
In order to suppress the extrusion of the resin to the circuit-forming metal and the edges of the base material, low flowability of the resin is required during heating and pressurization. In this regard, conventional adhesive sheets have OT flexibility, low flowability, and adhesive strength by adding a rubbery component to a thermosetting resin composition. However, since conventional adhesive sheets contain rubber-like components, they have the disadvantage that properties such as heat resistance, moisture resistance, and chemical resistance are greatly reduced.

On the other hand, conventional bonding methods for printed wiring boards, etc. have the following drawbacks.

First, in the conventional bonding method for printed wiring boards, etc., during machining after temporary bonding as described in Section L, a portion of the resin is melted by the heated trill, and it is scattered onto the bonding surface and the printed wiring board This caused unnecessary unevenness on the surface.

Second, with conventional bonding methods for printed wiring boards, etc., it takes too much time from temporary bonding to final bonding, which causes problems such as the resin absorbing moisture and dust adhering to the board surface. was.

[Problems to be Solved by the Invention] The present invention has been made to solve the above-mentioned problems in conventional adhesive sheets and methods for adhering the same.
The purpose of this is to uniformly and stably obtain a semi-cured adhesive state in a short time, to have excellent storage stability at room temperature, to have good adhesion at low flowability, and to have good heat resistance. Adhesive set T with satisfactory moisture resistance and chemical resistance
t1. and to provide an adhesion method that eliminates unevenness on the surface of a base material and eliminates the risk of moisture absorption and dust adhesion by applying an L-distributed adhesive to an adherend by screen printing. It is.

[Means for Solving the Problems] In order to achieve the above object, as a result of extensive research by the present inventors, the following adhesive composition and its method of use as an adhesive have been developed using conventional methods. I found that it was significantly better than.

In other words, the composition of the adhesive composition adopted in the present invention is "ultraviolet curable epoxy methacrylate resin composition (I
) and a thermosetting epoxy resin composition (
II) and kneaded a filler and a thixotropic agent into this mixture, the adhesive composition (m) has a viscosity of 200 to 500 P at a temperature of 25°C and a sliding speed of 1SeC-1 as measured by a B-type viscometer. S and has a thixotropic index of 10 to 60 as expressed by (viscosity at a sliding speed of 15 ec-' by a B-type viscometer)/(viscosity at a sliding speed of 1005 ec-' by a B-type viscometer) There is also a method for using such a composition as an adhesive for printed wiring boards, etc.

"Ultraviolet curable epoxy methacrylate resin composition 1r
) and a thermosetting epoxy resin composition (
II) and kneaded a filler and a thixotropic agent into this mixture.
00 to 5 oops, and a chickuntropic index expressed as (Bj [viscosity at sliding speed l 5ec-' by viscometer)/(viscosity at sliding speed + Ofl 5ec-' by B-type viscometer) is 10 to 60. Composition J.

The adhesive composition ( I [
This is method 1 for using an adhesive composition as an adhesive in which the above-mentioned ultraviolet curing or curing only the epoxy methacrylate resin composition <I) in parentheses [) is used.

The above means of the present invention will be explained in detail below.

The ultraviolet curable epoxy methacrylate resin composition (I) used in the present invention contains an epoxy methacrylate resin, a copolymerizable crosslinking agent, and a sensitizer as essential components.

First, the epoxy methacrylate resin used in the present invention is a bisphenol type epoxy methacrylate resin which is an addition reaction product of a bisphenol A type or bisphenol F type epoxy resin and methacrylic acid, a phenol novolac epoxy resin or a cresol novolac epoxy resin and methacrylic acid. The main component is at least one of the following: a novolac type epoxy methacrylate resin, which is an addition reaction product between a glycidyl ether type epoxy resin of a polyhydric alcohol, and an aliphatic epoxy methacrylate resin, which is an addition reaction product between a glycidyl ether type epoxy resin of a polyhydric alcohol, and methacrylic acid. That is. Further, in the present invention, an epoxy acrylate resin, which is an addition reaction product of these epoxy resins and acrylic acid, can also be copolymerized with an epoxy methacrylate resin and used, if necessary.

Examples of copolymerizable crosslinking agents include diallyl phthalate, triethylene glycol diacrylate, trimethylene propane triacrylate, etc., acrylic acid esters, trimethylolpropane trimethacrylate, and polypropylenes that react with epoxy methacrylate resins. A monomer having two or more saturated groups at the end or a prepolymer thereof can be used.

The copolymerizable crosslinking agent is epoxy methacrylate resin 100
@10 to 200 parts by weight, preferably 50 to 200 parts by weight
Preferably a total of 100 i. If it is less than 50 parts by weight, the viscosity of the epoxy methacrylate resin composition (I) becomes high, resulting in poor workability, and if it exceeds 100 parts by weight, the performance of the cured product will deteriorate, which is not preferable.

Next, as the #II sensitizer, benzophenone, Michler's ketone, benzyl dimethyl ketal, and thioxansones can be used.

These sensitizers are appropriately selected depending on the type of epoxy methacrylate resin mentioned above and the conditions of use.

Next, examples of epoxy resins used in the present invention include glycidyl ethers of polyhydric phenols such as bisphenol A, bisphenol F, phenol novolac resins, and cresol novolac resins, and polyhydric alcohols such as butanediol and polypropylene glycol. Examples include glycidyl-type epoxy resins such as glycidyl esters of carboxylic acids such as glycidyl ether, phthalic acid, and tetrahydrophthalic acid, and alicyclic-type epoxy resins obtained by epoxidizing intramolecular orphine bonds with peracetic acid or the like.

The epoxy curing agent used in the present invention is selected from one that does not easily react with the epoxy resin at room temperature or when exposed to ultraviolet rays, and that sufficiently hardens the epoxy resin when heated. 2. Acid anhydrides such as methylnadic anhydride and methyltetrahydrophthalic anhydride; 1-cyanoethyl derivatives and trimellitate-based imidazole derivatives such as 1-cyanoethyl-2-methylimidazole-trimelitate; 2.
4-diamino-6-(2”-methylimidazole-(1
'))-Imidazole compounds such as triazine compound-based imidazole derivatives such as -ethyl-s-'r-riazine;
Complexes of Lewis acids and aliphatic primary and secondary amines such as BF3-diethylamine complexes, dicyandiamide derivatives synthesized from cyanoethyl)ζ and dicyandiamide and aromatic amines, organic acid hydrazides such as adipic acid hydrazide and inphthalic acid hydrazide, diamino Examples thereof include maleonitrile and its derivatives, melamine and its derivatives, and amine imides synthesized from carboxylic acid esters, dimethyl or radines, and epoxy compounds.

These curing agents are appropriately selected depending on the type of epoxy resin mentioned above and usage conditions.

In addition, these curing agents include benzyldimethylamine, etc.
An imidazole compound such as a grade amine or 2-ethyl-4-methylimidazole may be added as a curing accelerator to such an extent that the epoxy will not be cured in a greenhouse.

Next, the mixing ratio of (I) to (U) is set to t, 1
It is desirable that it be within the range of /9 to 9/1. If it is smaller than l/9, the surface of the produced adhesive will become extremely sticky. If it is greater than 9/1, the proportion of unreacted (■) contained in the adhesive is too small, resulting in a decrease in adhesive strength. ♀ More preferably 3/7 to 7/3.

Fillers include fused silica, crystalline silica, alumina,
Examples include aluminum hydroxide, zirconium oxide, zirconium silicate, calcium carbonate, talc, titanium oxide, precipitated barium sulfate, and mica.

Examples of thixotropic agents include fine inorganic powders such as silica and magnesium oxide, metal soaps such as aluminum stearate and aluminum octoate, and organic bentonite. These thixotropic agents have a great influence on the titanium tropic index of the adhesive composition of the present invention and are important constituents.

Adhesive 11 composition according to the present invention is - (1) above, (■)
The composition contains a filler, a thixotropic agent, and a coloring agent, an antifoaming agent, etc., as necessary. As the coloring agent to be mixed here, Ja-free and organic pigments, disperse dyes, etc. can be used, and as the antifoaming agent, silicone oil, etc. can be used.

The adhesive composition of the present invention has characteristics suitable for forming an adhesive layer by a printing method such as screen printing or stamp printing. In other words, the viscosity at a temperature of 25°C and a shear rate of 1 sec on a B-type viscometer is 200
~500 P S, and (viscosity at a slip rate of 15 ec-' by a B-type viscometer>/(a slip rate of 1 by a B-type viscometer)
It is characterized by a titanium tropic index (viscosity of 0.005 ec-') of 10 to 60.

Since the adhesive composition of the present invention is a non-Newtonian fluid, in order to limit its viscosity, it is necessary to specify the type of viscometer and measurement conditions. A B-type viscometer was used to measure viscosity, and the measurement conditions were as follows.

When the temperature is 25°C and the shear rate is 15ec-'', 1
The adhesive composition of the present invention has a viscosity of 2 (JO to 5 oops).If the viscosity is less than 20 UPS, the resin will tend to get around to the back of the plate during screen printing, causing bleeding etc. If the viscosity exceeds 5 oops, the resin will not come out from the mesh of the screen,
A viscosity of 200 to 5 oops is suitable for the printing method because it tends to cause blurring and the like. The adhesive layer formed by screen printing using the adhesive composition of the present invention is filled between patterns,
Moreover, since the adhesive composition must also be applied to the pattern L, it is more preferable that the viscosity of the adhesive composition is 250 to 1511 PS.

Next, the titanium tropic index, which has a large relationship with screen printing characteristics, was measured using a CB type viscometer at a speed of 1 sec.
-' viscosity)/(shear rate by B-type viscometer 1005e
c-' viscosity), the adhesive composition of the present invention has a titanium trophic index of 1 rho 60. If the titanium tropic index is less than 10, it is likely that the solid shape formed by screen printing press 1 will sag. Conversely, if the thixotropic wI number exceeds 60, a squeegee or scraper etc. will be used during screen printing. When moving the resin, the resin does not flow off the squeegee or scraper, and 1 g
Due to these reasons, the titanium tropic index falls within the glorious range of 1O to 61. Especially 1
5) Fv is filled between patterns and is formed by a screen printing method using adhesive composition 11 of the present invention, and in addition, pattern 1. It is more desirable that the Titasotrovic index is in the range of 25 to 5, since the adhesive layer must be coated evenly and the irregularities on the surface of the adhesive layer must be made as small as possible.

The adhesive composition of the present invention is a composition containing an epoxy resin, an epoxy methacrylate resin, a curing agent, a sensitizer, a copolymerizable crosslinking agent, a filler, and a thixotropic agent, and has a viscosity within a predetermined range and a titasotropic index. It has no relation to the so-called -liquid type, two-liquid type, etc. That is, even in the case of a two-component adhesive composition, all adhesive compositions of the present invention have a viscosity and a titasotropic index within a predetermined range when mixed and used.

[Actions of the Invention] The present invention has the following effects by adopting the above measures.

First, in general, curing of UV-curable epoxy methacrylate resin is caused by the generation of radicals due to the decomposition of the sensitizer.
The terminal unsaturated group undergoes radical polymerization and hardens. less than,
The curing reaction formula of epoxy methacrylate resin is shown.

hv R-R'-→R.+°R'.-(1)H Next, the epoxy resin is generally cured by an addition reaction with the official group of the curing agent through an epoxy ring opening reaction. The curing reaction of an epoxy resin using an amine curing agent, which is a typical curing agent, is shown below.

→R-CI□-C1+-(:H2-Nil-I+'H H...(3) In the present invention, the formula (L) is cured by irradiation with ultraviolet light as shown in (2). The ultraviolet curable epoxy acrylate resin composition (I) and the thermosetting epoxy resin set (II) that is cured by heating as shown in formula (3) are mixed.This mixture is irradiated with ultraviolet rays. In this case, only the ultraviolet curable epoxy methacrylate resin composition (1) in the mixture is cured, and the 1% curable epoxy resin composition (n) is hardly cured, so it is stable even if the curing conditions are not strictly controlled. Moreover, since the thermosetting epoxy resin composition (n), which is cured by heating, hardly cures at room temperature, it becomes a semi-cured state with excellent storage stability. Compared to thermosetting resin compositions, ultraviolet curable resin compositions generally require a much shorter curing time, so workability is greatly improved.Moreover, the mixing of (I) and (■) described above Any semi-cured state can be selected by changing the ratio. This means that the flowability of the resin can be selected arbitrarily.

In addition, in order to give this mixture printing properties, a filler and a titanium agent are mixed to have a predetermined viscosity and titanium tropic index, and the mixture is applied by screen printing and cured with ultraviolet light. Because the product does not contain solvents.

After water adhesion, no voids occur or performance deterioration due to residual solvent occurs.

Second, by applying the adhesive using screen printing, machining can be performed before application, and no resin scattering occurs due to drilling. In addition, pressing immediately after printing reduces problems such as moisture absorption of the resin and dust adhesion to the surface of the substrate, which occur when the resin is left in the air.

[Example] Next, the present invention will be specifically explained using examples.

First, mixing examples of the adhesive composition of the present invention will be explained, but the present invention is not limited to the following blending examples.
In the formulation examples below, all "parts" refer to "parts by weight."

Example 1 100 parts of bisphenol A type epoxy methacrylate resin (average 'f amount 1000, Neoball 8104 manufactured by Nippon U-Pica Co., Ltd.) and 75 parts of diallyl butarate (manufactured by Osaka Maen Co., Ltd.) as a copolymerizable crosslinking agent. , 3.5 parts of benzophenone as a sensitizer was mixed, and this was used as composition (1).Also, bisphenol A type epoxy tree * (average molecular weight 380, manufactured by Yuka Ciel Co., Ltd. E-828) 10
Part 0, @! 4.0 parts of dicyandiamide is mixed as a cyanizing agent, and this is added to (II>, illll).
) and (rI) compositions at a ratio of 2:1. To 100 parts of this mixture, 33 parts of titanium oxide as a filler,
8.3 parts of talc and 8.3 parts of silica powder as a titanium agent were mixed and kneaded using a three-roll mill.

In Example 1, Michler's ketone was used as a sensitizer at 3.5
Example 1 except that 1 flOFf6 of NK ester TMPT (manufactured by Shin Nakamura Chemical Industry Co., Ltd.) was used as a copolymerizable crosslinking agent, 50 parts of fused silica was used as a filler, and 5.5 parts of fine magnesium oxide powder was used as a titanium agent. The same shall apply.

L! LfN-di Example 1 was the same as Example 1 except that 51 parts of talc was used as a filler and 5.5 parts of C silica fine powder was used as a titanium agent.

Example 1 except that 40 parts of crystalline silica was used as the filler and 7.5 parts of fine silica powder was used as the titanium agent.
Same as .

IV comparative example A reprint adhesive sheet with added rubbery components.

The mixed resin compositions of Examples 1 to 4 above were applied to the etched surface of the copper foil of the copper-clad A-layer board using a screen printer, and then heated using an ultra-high pressure mercury lamp at an intensity of 4 mw/cm'' for 5 minutes. The adhesive layers were semi-cured by irradiation with ultraviolet rays.The adhesive layers were evaluated by the following method, and the results are shown in the table.

(Rate of change over time): The calorific value before and after heat treatment at 100°C for 2 hours was measured by SC, and the change was determined from the formula shown below.

Rate of change over time = Calorific value before heat treatment 1 Calorific value after knee heat treatment)xto.

Calorific value before heat treatment (extrusion of resin): A copper-clad laminate with a hole of 1 cm in diameter and a semi-cured board with printed adhesive were heated at a temperature of 170°C and a pressure of 40 kg f/crn'. After bonding under press conditions for 90 minutes, the length of the resin protruding into the hole was measured.

(Contact vise): After bonding a copper foil with a thickness of 3SILm and a semi-cured board with printed adhesive under the above press conditions, cut the copper foil into 1cm width and measure beer strength. did.

(Heat resistance) 150 of the sample for beer strength measurement mentioned above
"C, beer strength after 240 hours of heat treatment.

(Moisture resistance vk): P of the sample for beer strength measurement listed in h.
Beer strength after 100 hours at T (121°C, 2 atm).

(Margin below) Table 1 As is clear from the table, the rate of change over time for each Example was approximately O, which indicates that hardening had hardly progressed even after heat treatment. From this, it can be seen that the adhesive of the present invention in the previously cured state has extremely excellent storage stability at room temperature.

Furthermore, the protrusion of the resin is explained in (I) and (II) above.
It can be seen that if the ratio is round, it will take almost the same value.

On the other hand, good adhesive strength results were obtained even when the resin protrusion was small. Furthermore, it was revealed that the decrease in adhesive strength after heat treatment or moisture absorption was smaller than in the comparative example, and the moisture resistance and body heat resistance were good.

In addition, the time required for semi-curing is extremely short, 5 minutes, and it can be seen that the productivity is significantly superior.

Further, the viscosity and ticotropic index of the resin composition in each example are shown in Table-2.

Table 2 Next, an example of the adhesive method of the present invention will be explained in more detail using the composition of Example 1 as an adhesive composition, but the adhesive method of the present invention is limited to the following example. It is not something that will be done.

First, as shown in the first factor, the composition (lO) of Example 1 was adjusted to 4! ! It was applied onto a machined printed circuit board (21) by a conventional screen printing method.

At this time, when using a stainless steel screen (mesh opening 178gm, emulsion thickness 40Bm), bleeding may occur due to the resin wrapping around the back of the plate, or blurring may occur due to poor resin coming out from the screen mesh.
There were no occurrences of anyone occurring during printing or when the plate was removed. In addition, after the combination & material (10) of Formulation Example 1 was applied by screen printing, it was ensured that it was placed around the conductive circuit (22) formed on the printed circuit board (21). .

The composition (10) coated by the screen printing method as described in 1- above was brought into a semi-cured state by irradiation with ultraviolet rays, and the composition (10) was used as a contact layer (11) as shown in FIG. A laminated substrate (23) as shown in FIG. 3 is stacked on top of this contact layer (11).

These were heated and pressurized using a hot platen.

The printed wiring board formed as described below exhibited extremely excellent characteristics as a semiconductor device (20) as shown in FIG. That is, the bonded substrate (23) is coated with the composition (
10) on a printed circuit board (21) to protect the conductive circuit (22). Since it is reliably bonded to the substrate (21), the conductor circuit (22) is reliably protected. In addition, in Fig. 4, the symbol (24)
indicates a silicon chip to be mounted on a printed circuit board (21), h, and symbol (25) indicates a sealing resin for protecting this silicon chip (24).

[Effects of the Invention] As is clear from the Examples, the adhesive of the present invention and its 4t=M method had the following advantages.

1. For ultraviolet irradiation to semi-cure the above (II)
Since there is almost no reaction, an adhesive layer that is always in a uniform semi-cured state can be obtained.

2. Since (n) does not react even at room temperature, an adhesive with extremely excellent storage stability can be obtained.

3. Since the product is semi-cured by curing with ultraviolet rays, curing time is short and productivity is high.

4. Since the adhesive resin composition does not contain any solvent, there is no need to worry about the generation of voids or poor product properties due to residual solvent after main pressing.

5. The resin flow can be determined by the mixing ratio of the above (I) and the above (II), and a stable flow can always be obtained.

6. Since it does not contain rubbery components, it is heat resistant, moisture resistant,
Excellent chemical resistance.

7. Since the adhesive is applied using the screen printing method, machining that causes resin scattering can be performed before printing, and there is no unevenness on the substrate surface caused by resin scattering.

8. Since the process from printing to pressing is completed in a short time, there is no risk of moisture absorption or dust adhesion during the process.

[Brief explanation of the drawing]

Figures 1 to 3 are cross-sectional views illustrating the bonding method of the present invention, in which the adhesive composition of the present invention is applied to a printed circuit board by screen printing, cured, and then heated and pressed using a hot platen. be. FIG. 4 is a partially enlarged sectional view of a semiconductor device using the adhesive composition of the present invention as an adhesive on a substrate for mounting a semiconductor element. Explanation of symbols 1O...adhesive fA composition, lt...adhesive layer, 21.
...Printed circuit board, 22--conductor circuit, 23--laminated board, 24--silicon chip, 25" seal and resin. That's all for Figure 4.

Claims (1)

[Claims] 1) An ultraviolet curable epoxy methacrylate resin composition (I) and a thermosetting epoxy resin composition (II) containing a latent curing agent that does not or is difficult to cure by ultraviolet irradiation. The adhesive composition (III) is obtained by kneading a filler and a thixotropic agent into this mixture, and the temperature is 25°C and the shear rate is 1 sec by a B-type viscometer.
1 has a viscosity of 200 to 500 PS and a thixotropic index expressed as (viscosity at a shear rate of 1 sec^-^1 by a B-type viscometer)/(viscosity at a shear rate of 100 sec^-^1 by a B-type viscometer) An adhesive composition characterized in that it has a molecular weight of 10 to 60. 2) The ultraviolet curable epoxy methacrylate resin composition (I) is a bisphenol-type epoxy methacrylate resin obtained by adding methacrylic acid to a bisphenol-type epoxy resin, or a novolak-type epoxy methacrylate resin obtained by adding methacrylic acid to a novolak-type epoxy resin. Alternatively, at least one resin selected from aliphatic epoxy methacrylate resins obtained by adding methacrylic acid to glycidyl ether type epoxy resins of polyhydric alcohols, a copolymerizable crosslinking agent, and a sensitizer are essential components. The adhesive composition according to claim 1, characterized in that: 3) The adhesive composition according to claim 1 or 2, wherein the thermosetting epoxy resin composition (11) contains an epoxy resin and a curing agent as essential components. . 4) The thermosetting epoxy resin composition (II) of the ultraviolet curable epoxy methacrylate resin composition (I)
4. The adhesive composition according to any one of claims 1 to 3, wherein the mixing ratio is within the range of 1/9 to 9/1. 5) Mix the ultraviolet curable epoxy methacrylate resin composition (I) and the thermosetting epoxy resin composition (II) containing a latent curing agent that does not or is difficult to cure by ultraviolet irradiation, and add to this mixture. An adhesive composition (III) obtained by kneading a filler and a thixotropic agent, which has a viscosity of 200 to 500 PS at a temperature of 25°C and a shear rate of 1 sec^-^1 as measured by a B-type viscometer, and ( An adhesive composition having a thixotropic index of 10 to 60 expressed as viscosity at a shear rate of 1 sec^-^1)/(viscosity at a shear rate of 100 sec^-^1 measured by a B-type viscometer) is printed wiring by a screen printing method. After applying the adhesive composition (III) to the surfaces of both or either of the boards, the printed wiring board and the base material, or the printed wiring board and the copper foil, the adhesive composition (III) is irradiated with ultraviolet rays. A method for using an adhesive composition as an adhesive, which comprises curing only the ultraviolet curable epoxy methacrylate resin composition (I) in the composition (III).