JP2002020722A - Adhesive and method for adhering therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for adhering by which the thickness of an adhesive layer can suitably be controlled. SOLUTION: This method for adhering two articles 10, 20 to each other, characterized by intervening between the articles 10, 20 an adhesive 30 comprising a liquid or sheet-like adhesive material 31 in which particles having a larger hardness than that of the adhesive material portion and an approximately uniform particle diameter 32 are dispersed, and controlling the thickness of the adhesive layer to the approximately same length as the particle diameter of the particles 30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive capable of appropriately controlling the thickness of an adhesive layer, and an adhesive method using the same.

[0002]

2. Description of the Related Art As is well known, when two articles (members), for example, a metal plate, a substrate, a plastic plate, a ceramics plate, and the like are adhered by an adhesive, an adhesive is applied between these two articles and adhered. That is often done.

On the other hand, the adhesives used in this manner include:
Various types have already been proposed, and as for the main components, thermoplastic resin type, thermosetting resin type, rubber type, and even composite type in which these are mixed are listed. There are things.

[0004] These adhesives are used in the form of a liquid or processed in advance into a sheet, and in any case, the adhesive can be obtained by curing the adhesive.
Furthermore, in order to improve the adhesive strength or to shorten the curing time, an appropriate catalyst, a curing agent, a curing accelerator, or the like may be appropriately mixed, or a treatment such as heating and pressing may be performed at the time of bonding. is there.

[0005]

However, when two articles are bonded with such an adhesive, it is difficult to control the thickness of the adhesive layer portion in the product after bonding to a constant value, resulting in variation. It often happens. For example, as shown in FIG. 3, when obtaining a product having a predetermined thickness t (including an intermediate) including the two articles 1 and 2 and the adhesive layer 3, the entire surfaces of both articles 1 and 2 It is quite difficult to apply a uniform pressure over a period of time, and when the pressure becomes uneven, as shown in FIG.
A phenomenon occurs in which the articles 1 and 2 are not bonded in parallel.

Further, even if a uniform pressure can be applied, if the pressure is too strong, as shown in FIG.
If the adhesive layer 3 is too thin to obtain a predetermined thickness t, or conversely, if the pressure at the time of bonding is small, it will be thicker than the predetermined thickness t as shown in FIG. A phenomenon occurs.

As described above, it is quite difficult to optimally control the thickness of the adhesive layer when two articles are bonded by the adhesive. In particular, such as parts for electronic equipment,
It was extremely difficult to control the thickness of the adhesive layer between the articles on the order of several μm to several tens μm.

[0008] The present invention has been made in view of such a conventional situation, and specific particles are intentionally dispersed in an adhesive material, and the thickness of the adhesive layer is appropriately controlled by the particle diameter of the particles. It is an object of the present invention to provide a novel adhesive and a method for bonding the same.

[0009]

According to the first aspect of the present invention, there is provided a liquid or sheet-like adhesive material in which particles having a hardness greater than that of the adhesive material and a particle diameter substantially uniform are dispersed. An adhesive characterized in that:

According to a second aspect of the present invention, there is provided the adhesive according to the first aspect, wherein a dispersion ratio of the particles in the adhesive material is set to 50% or less.

According to a third aspect of the present invention, in bonding two articles, in the liquid or sheet-like adhesive material between the two articles, the hardness is larger than the adhesive material portion and the particle size is substantially uniform. An adhesive method in which an adhesive in which fine particles are dispersed is interposed, and the thickness of the adhesive layer is controlled to be substantially the same as the particle diameter of the particles.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an example in which two articles are bonded using the adhesive according to the present invention, and FIG. 2 is an enlarged view thereof. In the figure, reference numerals 10 and 20 denote substrates such as metal plates (foil) and printed wiring boards, plastic sheets (plates) such as FPCs, ceramic plates, etc., which are used in, for example, parts for electronic devices. The two articles 30 to be bonded are a liquid or sheet-like adhesive for adhering these two articles 10 and 20, 31 is the adhesive material, and 32 is particles dispersed in the adhesive material 31.

The adhesive 30 in the present invention is not particularly limited. As in the prior art, the adhesive 30 is of a thermoplastic resin type, a thermosetting resin type, a rubber type, or a composite type obtained by mixing these. Things can be used. Then, in the adhesive material 31 of the adhesive 30, an appropriate catalyst, a curing agent, a curing accelerator, and the like can be appropriately mixed as necessary, as in the related art.

The particles 32 dispersed in the adhesive material 31
For example, spherical particles are preferable (lumps such as cubes having a uniform shape can also be used), and examples thereof include spherical particles such as alumina, acrylic resin, and solder balls.
In addition, it is required that the material be harder than the adhesive material 31 and have a substantially uniform particle size.

First, as shown in FIG. 2, the thickness t ₀ of the adhesive layer portion between the two articles 10 and 20 is controlled to be substantially constant in relation to the particle size of the particles 32. By setting the thickness t between the two articles 10 and 20,
This is because at least the portion of the adhesive material 31 is required to be harder.

If the particles 32 themselves cannot be maintained in the adhesive material 31 due to softening or melting, the function of maintaining the thickness t ₀ of the adhesive layer portion cannot be obtained, and However, even if the adhesive layer is easily crushed by an external pressure at the time of bonding, the function of maintaining the thickness of the adhesive layer cannot be obtained, so the hardness includes such characteristics.

Next, if the particle size of the particles 32 varies, it becomes difficult to keep the thickness t ₀ of the adhesive layer portion almost constant, so that the particle size is required to be substantially uniform. Because it is done. In particular, since the thickness t ₀ of the adhesive layer portion is determined by the maximum particle size of the particles 32, it is preferable that the thickness t ₀ be substantially uniform on the maximum particle size side.

However, a sheet-like adhesive (adhesive sheet)
In this case, since the sheet thickness is reduced by pressure bonding during normal bonding, the maximum particle size of the particles 32 is 80% of the sheet thickness after bonding.
% To 50% or more.

The dispersion ratio of the particles 32 having the above function in the adhesive material 31 is preferably 50% or less with respect to the adhesive volume. The reason for this is that if the dispersion ratio of the particles 32 is larger than this, the adhesive material 31 is reduced accordingly, and there is a possibility that sufficient adhesive strength may not be obtained.

Example 1 Under the conditions shown in Table 1,
Using a liquid adhesive in which particles (80 μm, 50 μm) having a substantially uniform maximum particle size were dispersed, a sample (Example product) in which two copper plates were bonded was prepared. Specifically, first, after a liquid adhesive was applied to one copper plate, the other copper plate was brought into close contact with the copper plate, and an external pressure was applied between the two copper plates for 20 seconds. The external pressure at this time is 5 kgf / cm ² , 10 kgf
/ Cm ² and 20 kgf / cm ² . Thereafter, it was placed in a furnace maintained at 160 ° C. and dried. Further, for comparison, a similar sample (comparative product) was prepared using a normal liquid adhesive containing no particles. Implementation conditions Copper plate: 1 mm (thickness) x 10 mm (length) x 10 mm
(Horizontal) Adhesive: Thermosetting resin-based dispersed particle material used: Alumina, acrylic resin, solder ball Particle dispersion: 50% or less Adhesive applied amount: 10 mm ³

The change in the thickness (μm) of the adhesive layer in each of the above samples (Example product and Comparative example product) was examined. From Table 1, it can be seen that in the example product of the present invention, the thickness of the adhesive layer is hardly influenced by the external pressure, is almost equal to the maximum particle size of the dispersed particles, and is well controlled. On the other hand, it can be seen that the thickness of the adhesive layer greatly depends on the external pressure in the conventional comparative example product. In the examples of the present invention, the reason why the thickness of the adhesive layer is slightly larger than the maximum particle size of the dispersed particles in some cases is considered to be that the adhesive material is interposed in the gap between the particles and the copper plate. .

[0022]

[Table 1]

Example 2 Under the conditions shown in Table 2,
Using a sheet-like adhesive (adhesive sheet) in which particles (80 μm, 50 μm) having a substantially uniform maximum particle size are dispersed, 2
A sample (Example product) in which two copper plates were bonded was prepared. Specifically, first, an adhesive sheet was placed on one copper plate by 80
After temporarily press-bonding at ² ° C. and ² kgf / cm ² for 5 seconds, the other copper plate was brought into close contact, and an external pressure was applied between the two copper plates at 160 ° C. for 20 seconds to perform final pressure bonding. The external pressure at this time is 5 kg
f / cm ² , 10 kgf / cm ² , 20 kgf / cm ²
Of three types. Further, for comparison, a similar sample (comparative product) was prepared using a sheet-like adhesive containing no particles. Implementation conditions Copper plate: 1 mm (thickness) x 10 mm (length) x 10 mm
(Horizontal) Adhesive: Thermosetting resin type Dispersed particle material used: Alumina, acrylic resin, solder ball Particle dispersion: 50% or less Adhesive sheet thickness: 100 μm

Table 2 shows the change in the thickness (μm) of the adhesive layer in each sample (Example product and Comparative product). From Table 2, it can be seen that in the example product of the present invention, the thickness of the adhesive layer is hardly influenced by the external pressure, is almost equal to the maximum particle size of the dispersed particles, and is well controlled. On the other hand, it can be seen that the thickness of the adhesive layer greatly depends on the external pressure in the conventional comparative example product. In the examples of the present invention, the reason why the thickness of the adhesive layer is slightly larger than the maximum particle size of the dispersed particles in some cases is considered to be that the adhesive material is interposed in the gap between the particles and the copper plate. .

[0025]

[Table 2]

[0026]

As is clear from the above description, according to the adhesive and the bonding method using the same according to the present invention, the thickness of the adhesive layer between two articles to be bonded depends on the particle size of the particles to be dispersed. Can be easily and accurately controlled. In addition, the thickness of the adhesive layer can be controlled in the order of several μm to several tens μm by setting the particle diameter of the particles. Can provide significant benefits.

[Brief description of the drawings]

FIG. 1 is an example of a longitudinal sectional view showing a state where two articles are adhered by an adhesive according to the present invention.

FIG. 2 is an enlarged vertical sectional view of FIG.

FIG. 3 is an explanatory diagram showing a case in which two articles are adhered to each other with a constant thickness using a normal adhesive.

FIG. 4 is an explanatory diagram showing a case where two articles are inclined and adhered by a normal adhesive;

FIG. 5 is an explanatory diagram showing a case where two articles are bonded to each other with a thickness smaller than a predetermined thickness using a normal adhesive.

FIG. 6 is an explanatory diagram showing a case where two articles are bonded to each other with a normal adhesive so as to be thicker than a predetermined thickness.

[Explanation of symbols]

 10, 20 Article 30 Adhesive 31 Adhesive material 32 Particle

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kenichi Okada 1-5-1, Kiba, Koto-ku, Tokyo F-term in Fujikura Co., Ltd. (Reference) 4J040 DF022 HA076 HA136 HA09 JA09 KA03 LA03 PA21 PA23 PA24

Claims (3)

[Claims] 1. An adhesive characterized in that particles having a hardness higher than that of an adhesive material portion and a particle diameter substantially uniform are dispersed in a liquid or sheet-like adhesive material. 2. The adhesive according to claim 1, wherein a dispersion ratio of the particles in the adhesive material is set to 50% or less. 3. In bonding two articles, an adhesive in which particles having a hardness higher than that of the adhesive material and a particle having a substantially uniform particle size are dispersed in a liquid or sheet-like adhesive material is interposed between the two articles. And controlling the thickness of the adhesive layer to be substantially the same as the particle size of the particles.