KR101653369B1 - Thermally conductive adhesive composition and thermally conductive adhesive thin sheet therefrom - Google Patents

Abstract

The present invention relates to a thermally conductive pressure-sensitive adhesive composition capable of minimizing delamination due to curing shrinkage and capable of improving thermal conductivity and a thermally conductive thin film pressure-sensitive adhesive sheet prepared therefrom. To this end, an acrylic resin, a thermosetting agent, A thermally conductive pressure-sensitive adhesive composition comprising a thermally conductive filler in the form of a thermally conductive adhesive.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a thermally conductive pressure-sensitive adhesive composition and a thermally conductive thin-

The present invention relates to a thermally conductive pressure-sensitive adhesive composition and a thermally conductive pressure-sensitive adhesive sheet prepared therefrom, and more particularly, to a thermally conductive pressure-sensitive adhesive composition capable of minimizing delamination due to curing shrinkage and improving thermal conductivity, And a thermally conductive thin film adhesive sheet produced thereby.

In general, semiconductor technology for the development of next generation electronic devices is being developed as a highly integrated technology for light weight shortening and multifunctionalization. However, the driving of such a highly integrated device causes heat emission inside the device. Especially in recent years, the use of the portable module device has been rapidly increasing, and the high thermal density in the device due to the miniaturization of the electronic device device shortens the reliability and lifetime of the device. Results. In addition, for faster processing speed and safety, there is a growing awareness and demand for heat dissipation at the device level and heat dissipation at the level of electronic components or IC packages.

On the other hand, a heat sink or a heat-dissipating fan is generally used as a method for discharging heat generated from the inside to the outside. The heat sink has a principle of maximizing the contact area with the outside air to radiate heat to the outside, while the radiating fan has a principle of forcibly discharging the heat to the outside through the fan. Particularly, in terms of heat dissipation efficiency, .

However, in recent electronic appliances and semiconductor device packages, it is impossible to mount the heat dissipating fan and the heat sink in accordance with the requirement of thin and light shortening, and a method of directly discharging the heat generated in the heat generating portion to a heat spreader or the like use. At this time, a heat conduction material is necessarily required for efficient heat transfer between the heat generating part such as the semiconductor chip and the heat spreader. As such a heat conductive material applied between the heat generating portion and the heat spreader, a composite material containing high thermal conductive fillers is usually used for the polymer resin. Examples of the form of the heat conduction material include a paste type, a gel type, a phase transition material, and a film type.

For example, Korean Patent Laid-Open Publication No. 2008-0096453 has selected paste type heat conductive materials. The paste type heat dissipation material has an advantage of being excellent in wetting property and minimizing the contact heat resistance. However, since the IC package has been thinned and shortened, and the management range of the structural dimension of the package itself has been narrowed from tens to hundreds of micrometers A problem has arisen with respect to the use of a paste-type material causing a Bound Line Thickness (BLT) deviation of several tens of 탆. In addition, since the paste type is dispensed on the surface and then fixed by a hardening process, a thin and small IC package has a serious problem of warpage due to hardening shrinkage, which limits its application.

In addition, Korean Patent Laid-Open Publication No. 2011-0119256 selects sheet-shaped heat conductive materials using monomolecular epoxy. However, in the case of the adhesive material using the curing of the monomolecular epoxy, the BLT (Bond Line Thickness) control is easy because of the sheet shape. However, since the hardness of the surface is relatively high, Bubbles may be trapped on the surface of the heat spreader or the surface of the heat sink fin. Further, after mounting on a substrate, curing shrinkage occurs in the pressure-sensitive adhesive layer itself due to the thermosetting step, which may cause delamination problems with the substrate. In other words, the heat conduction efficiency of the IC package is lower than that of the actual pressure-sensitive adhesive layer.

Korean Patent Registration No. 10-1374818 discloses a resin composition excellent in mechanical properties such as tensile strength, flexural modulus and impact strength by using a thermoplastic resin and a spherical polysilicon compound and a platelet graphite as filler. However, since the thermal conductivity is not high and the thermoplastic resin is difficult to be formed into a thin film, it is difficult to use the thermoplastic resin for mounting a thin and light electronic device.

On the other hand, since the thermal conductivity of general polymer resin is very low, 0.1 to 0.5 W / m · K, the heat is transmitted through the thermally conductive filler dispersed in the polymer resin. For the purpose of increasing the thermal conductivity, It is difficult to obtain the sheet in the form of a sheet because the flexibility of the pressure-sensitive adhesive layer is lowered, and it is difficult to realize the adhesive property.

Korean Patent Laid-Open Publication No. 2008-0096453 Korean Patent Laid-Open Publication No. 2011-0119256 Korean Patent Registration No. 10-1374818

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a thermoconductive pressure sensitive adhesive composition capable of minimizing delamination due to curing shrinkage and capable of improving thermal conductivity and a thermally conductive thin film So as to provide a pressure-sensitive adhesive sheet.

These and other objects and advantages of the present invention will become more apparent from the following description of a preferred embodiment thereof.

The above object is achieved by a thermally conductive pressure-sensitive adhesive composition, which comprises an acrylic resin, a thermosetting agent and thermally conductive fillers of at least two shapes.

Here, the acrylic resin may be an acrylate copolymer obtained by copolymerizing 85 to 99% by weight of a monomer having no cross-linkable functional group with 1 to 15% by weight of a monomer having a cross-linkable functional group, based on the total weight of the monomers constituting the acrylic copolymer Lt; / RTI >

Preferably, the thermally conductive filler may be a spherical filler (A) having an average particle diameter of 0.1 to 20 μm and a plate-like filler (B) having an average long diameter of 1 to 20 μm.

Preferably, the spherical filler (A) may be selected from metals, ceramics and carbon materials having a Young's modulus of 250 to 600 GPa.

Preferably, the plate-like filler (B) may be one obtained by physically deforming spherical metal particles having a Young's modulus of 10 to 100 GPa into a plate shape by collision with ceramic beads having a Young's modulus of 150 to 200 GPa.

Preferably, the plate-like filler (B) has a thickness-to-diameter ratio of 1: 3 to 1:10.

Preferably, 0.3 to 10 parts by weight of the thermosetting agent, 200 to 700 parts by weight of the spherical filler (A), and 100 to 400 parts by weight of the plate-like filler (B) are added to 100 parts by weight of the acrylic resin.

The above objects are also achieved by a thermally conductive thin film adhesive sheet characterized by comprising a pressure-sensitive adhesive layer formed of the above-mentioned thermally conductive pressure-sensitive adhesive composition and a base film applied on both surfaces of the pressure-sensitive adhesive layer.

Here, the thickness of the pressure-sensitive adhesive layer may be 10 탆 to 100 탆.

Preferably, the thermally conductive thin-film adhesive sheet has a thermal conductivity in the thickness direction of 1.5 W / m · K or more, and a delamination area ratio to the metal substrate may be 10% or less.

According to the present invention, it is possible to minimize delamination due to curing shrinkage which may occur in a heat curing process of a conventional paste-type thermally conductive material or a thermally conductive sheet of an adhesive type, and it is possible to minimize delamination by mixing a spherical filler and a plate- And the thermal conductivity is improved.

However, the effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by those skilled in the art from the following description.

1 is a sectional view of a thermally conductive thin film adhesive sheet according to an embodiment of the present invention.
2 is a photograph showing a manufacturing process through physical modification of a plate-shaped filler used in a thermally conductive pressure-sensitive adhesive composition according to an embodiment of the present invention.

Hereinafter, the present invention will be described in detail with reference to embodiments and drawings of the present invention. It will be apparent to those skilled in the art that these embodiments are provided by way of illustration only for the purpose of more particularly illustrating the present invention and that the scope of the present invention is not limited by these embodiments .

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In case of conflict, the present specification, including definitions, will control. Also, although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods and materials are described herein.

The thermoconductive pressure sensitive adhesive composition according to an embodiment of the present invention is characterized by including an acrylic resin, a thermosetting agent, and at least two types of thermally conductive fillers. The pressure-sensitive adhesive layer formed from such a thermally conductive pressure-sensitive adhesive composition may have a crosslinked structure formed by thermal curing.

In the present specification, a thermal conductive adhesive composition comprising an acrylic resin, a spherical filler and a plate-like filler is proposed, thereby controlling the thickness and length ratio of the plate-like filler to increase the probability of contact between the fillers, thereby establishing a heat transfer network inside the adhesive sheet Lt; / RTI > According to one embodiment of the present invention, the thermal conductivity can be improved without increasing the content of the thermally conductive filler extremely, and the adhesive property can be secured. Therefore, compared with the conventional adhesive thermally conductive adhesive sheet, It is possible to minimize delamination at the surface of the substrate by the method of the present invention.

Hereinafter, each composition will be described in detail.

1. Thermoconductive adhesive composition

1-1. Acrylic resin

The acrylic resin, which is one component of the thermoconductive pressure-sensitive adhesive composition according to an embodiment of the present invention, is made of an acrylate copolymer, and more specifically, it is an acrylic copolymer having no cross-linkable functional groups based on the total weight of monomers constituting the acrylic copolymer A copolymer obtained by copolymerizing 85 to 99% by weight of a monomer and 1 to 15% by weight of a monomer having a crosslinkable functional group. When the amount of the monomer having no crosslinkable functional group in the pressure-sensitive adhesive composition is less than 85% by weight, the problem of the storage stability of the pressure-sensitive adhesive due to the relatively large number of functional groups and the deterioration of the cohesive force of the pressure- If it exceeds 99% by weight, the reactivity of the functional group is remarkably lowered, so that the reaction may not be performed well and the cohesion is deteriorated due to the decrease of the degree of crosslinking.

The acrylic copolymer preferably has a weight average molecular weight of 100,000 to 3,000,000, more preferably 40 to 1,000,000. When the weight average molecular weight is less than 100,000, cohesive failure may occur, while when the weight average molecular weight exceeds 300,000, the viscosity may be increased and the workability may be deteriorated.

The monomer having no crosslinkable functional group is (meth) acrylic acid ester monomer, but is not particularly limited. Preferably, the monomer not having a crosslinkable functional group includes a (meth) acrylic acid ester in which the alkyl group of the ester moiety has 1 to 20 carbon atoms. Examples of the (meth) acrylic acid ester having 1 to 20 carbon atoms in the alkyl moiety of the ester moiety include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) (Meth) acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl Acrylate, myristyl (meth) acrylate, palmityl (meth) acrylate, and stearyl (meth) acrylate. These may be used alone or in combination of two or more.

The monomer containing a crosslinkable functional group preferably contains at least one of a hydroxyl group, a carboxyl group, an amino group and an amide group as a functional group. Specific examples of such a monomer include 2-hydroxyethyl (meth) acrylic acid, 2- (Meth) acrylic acid such as propyl (meth) acrylic acid, 3-hydroxypropyl (meth) acrylic acid, 2- hydroxybutyl (meth) acrylic acid, 3- hydroxybutyl (meth) acrylic acid, Acrylic acid hydroxyalkyl esters; Acrylamides such as N-methyl (meth) acrylamide, N-methyl (meth) acrylamide and N-methylol (meth) acrylamide; Monomethylaminoethyl (meth) acrylate, monoalkylamino (meth) acrylate; And ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid and citraconic acid. These monomers may be used alone or in combination of two or more.

1-2. Heat curing agent

The acrylic resin of the thermoconductive pressure sensitive adhesive composition according to an embodiment of the present invention can be used by adding a suitable crosslinking agent. Any crosslinking agent or curing agent can be used as long as it can cure a resin having a hydroxyl group as a functional group. Specifically, melamine, poly (urea-formaldehyde), aryl isocyanate, and the like can be given.

The amount of the thermosetting agent is preferably 0.3 to 10 parts by weight, preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the acrylic resin. When the amount of the thermosetting agent is less than 0.3 parts by weight based on 100 parts by weight of the acrylic resin, the crosslinking structure is not sufficiently formed and the pressure-sensitive adhesive layer is excessively retreated (relative glass transition temperature is decreased and loss modulus is increased) If the amount of the thermosetting agent exceeds 10 parts by weight based on 100 parts by weight of the acrylic resin, the acrylic resin becomes excessively hard and the pressure-sensitive adhesive layer becomes too hard. As a result, the adhesive strength and wettability are too low, The bubble may be trapped because the surface roughness of the surface of the substrate is not sufficiently filled, and in the worst case, too much hardness may cause a problem that the pressure-sensitive adhesive layer is broken during the lamination process.

1-3. Thermally conductive filler

Examples of the thermally conductive filler include spherical, plate or needle powder such as metal, metal oxide, metal nitride, metal carbide, and metal hydroxide, and carbon material. Examples of the metal include gold, silver, aluminum and copper. Examples of the metal oxide include aluminum oxide, magnesium oxide, zinc oxide and iron oxide. Examples of the metal nitride include boron nitride and aluminum nitride . Examples of the metal carbide include silicon carbide and tungsten carbide, and examples of the metal hydroxide include aluminum hydroxide. Examples of the carbon material include pitch-based carbon fibers, PAN-based carbon fibers, fibers obtained by carbonizing resin fibers, fibers obtained by graphitizing resin fibers, carbon nanotubes, carbon black, graphite and graphene.

The thermally conductive filler, which is the third component of the thermally conductive pressure-sensitive adhesive composition according to one embodiment of the present invention, includes two or more kinds of shapes represented by a spherical filler (A) and a sheet-like filler (B) And dispersed in the acrylic resin through a dispersion method using collision energy of ceramic beads having a Young's modulus of 150 to 200 GPa.

The spherical filler (A) is preferably selected from metals, ceramics and carbon materials having a Young's modulus of 250 to 600 GPa, and preferably 200 to 700 parts by weight based on 100 parts by weight of the acrylic resin. If the amount is less than 200 parts by weight, a high thermal conductivity can not be achieved. If the amount is more than 700 parts by weight, flexibility of the pressure-sensitive adhesive sheet can not be ensured and the pressure-sensitive adhesive sheet may be broken. The spherical filler (A) preferably has an average particle diameter of 0.1 to 20 mu m. When the average particle diameter is less than 0.1 탆, the number of interfaces between the filler and the acrylic resin is increased and the probability of contact with the plate-like filler (B) is lowered. Thus, there is a possibility that the thermal conductivity of the adhesive sheet is lowered. , There is a possibility that a large roughness is generated on the surface of the pressure-sensitive adhesive layer, and there is a possibility that the bubble is trapped during lamination to the substrate.

2, which is a photograph showing a manufacturing process through physical modification of the plate-like filler used in the thermally conductive pressure-sensitive adhesive composition according to an embodiment of the present invention, the plate-like filler (B) is a spherical metal having a Young's modulus of 10 to 100 GPa The particle shape is physically deformed from a spherical shape to a plate shape due to collision with ceramic beads having a Young's modulus of 150 to 200 GPa, and the probability of contact with the spherical filler (A) in the acrylic resin is increased and the thermal conductivity It is preferable that the thickness of the filler (B) deformed into a plate shape: the long diameter ratio is in the range of 1: 3 to 1:10. When the thickness ratio of the sheet-like filler (B) is 1: 3 or less, the probability of contact with the spherical filler (A) is not effectively improved and the improvement of the thermal conductivity is limited. When the thickness: The contact probability becomes too high, and since many contact points between the pillars are generated, the heat is not transmitted directionally and scattered, so efficient heat conduction is not achieved. The amount of the sheet-like filler (B) is preferably 100 to 400 parts by weight based on 100 parts by weight of the acrylic resin. If the amount is less than 100 parts by weight, a high thermal conductivity can not be realized. If the amount is more than 400 parts by weight, flexibility of the pressure-sensitive adhesive sheet can not be ensured and the pressure-sensitive adhesive sheet may be broken. The average long diameter of the sheet-like filler (B) is preferably 1 to 20 mu m. When the average long diameter is less than 1 占 퐉, the number of interfaces between the filler and the acrylic resin is increased and the probability of contact with the spherical filler (A) is low, so there is a possibility that the thermal conductivity of the adhesive sheet is lowered. , There is a possibility that a large roughness is generated on the surface of the pressure-sensitive adhesive layer, and there is a possibility that the bubble is trapped during lamination to the substrate.

The mixing ratio of the spherical filler (A) and the sheet-like filler (B) may be varied to increase the filling ratio of the thermally conductive filler in the adhesive sheet and the probability of contact between each filler. Specifically, The filler fill factor in the interior of the adhesive sheet and the probability of contact between the fillers can be maximized as the average diameter or the average diameter of the filler and the thickness of the plate-like filler (B): long diameter ratio are changed.

2. Base film

The kind of the base film is preferably selected from conventional general melamine-based, fluorine-based or silicone-based release films.

3. Adhesive Sheet

1, a thermally conductive thin film adhesive sheet according to an embodiment of the present invention will be described. Referring to Fig. 1, the pressure-sensitive adhesive sheet is composed of a pressure-sensitive adhesive layer 12 formed by applying the above-mentioned thermally conductive pressure-sensitive adhesive composition between a base film 11, 11 'and a base film 11, 11'.

The thickness of the pressure-sensitive adhesive layer is preferably from 10 탆 to 100 탆. If the thickness is less than 10 mu m, it is difficult to maintain the sheet shape. If the thickness exceeds 100 mu m, the distance between the heating portion and the heat spreader of the light and thinned electronic device may become distant, and the heat conduction characteristics may deteriorate.

The thermally conductive pressure-sensitive adhesive sheet according to the present invention preferably has a thermal conductivity in the thickness direction of 1.5 W / m · K or more and a delamination area ratio to the metal substrate of 10% or less

Hereinafter, the structure and effect of the present invention will be described in more detail with reference to examples and comparative examples. However, this embodiment is intended to explain the present invention more specifically, and the scope of the present invention is not limited to these embodiments.

[Production example: Production of plate-like filler (B)

400 parts by weight of beads made of zirconium oxide having a Young's modulus of 200 GPa were charged into 100 parts by weight of silver particles (mean particle diameter: 1 mu m) among the spherical metal particles having a Young's modulus of 100 GPa or less, 300 parts by weight of methyl isobutyl ketone was added, And dispersed using a dispersing machine of a net milling method to obtain platelet-shaped metal particles (B). The degree of physical deformation (thickness: long diameter ratio) of the plate-shaped metal particles (B) was controlled by controlling rpm and running time of the planetary milling machine.

≪ Example 1 >

300 parts by weight of methyl isobutyl ketone was added to 100 parts by weight (based on solid content) of an acrylic resin (Samwon, AT-2100) and 500 parts by weight of spherical aluminum nitride (Tokuyama, average particle size 1 탆) (Sigma Aldrich, thickness: long diameter ratio of 1: 3, average long diameter: 3 占 퐉) 300 parts by weight were charged and stirred for 1 hour. Thereafter, 0.5 part by weight of an isocyanate-based thermosetting agent (Samwon, CAT-45) was added and stirred for 1 hour to prepare a pressure-sensitive adhesive composition.

The pressure-sensitive adhesive composition was coated on one surface of a silicone type release film (XD5BR, 38 탆) of a silicone release film (XD5BR, 38 탆) at a thickness of about 40 탆 and dried at 130 캜 for 3 minutes (thermosetting) ) Was applied to produce a pressure-sensitive adhesive sheet.

≪ Example 2 >

300 parts by weight of methyl isobutyl ketone was added to 100 parts by weight (based on solid content) of an acrylic resin (Samwon, AT-2100) and 500 parts by weight of spherical aluminum nitride (Tokuyama, average particle size 1 탆) (Sigma Aldrich, thickness: long diameter ratio 1:10, average long diameter 5 占 퐉) 300 parts by weight were charged and stirred for 1 hour. Thereafter, 0.5 part by weight of an isocyanate-based thermosetting agent (Samwon, CAT-45) was added and stirred for 1 hour to prepare a pressure-sensitive adhesive composition.

The pressure-sensitive adhesive composition was coated on one surface of a silicone type release film (XD5BR, 38 탆) of a silicone release film (XD5BR, 38 탆) at a thickness of about 40 탆 and dried at 130 캜 for 3 minutes (thermosetting) ) Was applied to produce a pressure-sensitive adhesive sheet.

≪ Example 3 >

300 parts by weight of methyl isobutyl ketone was added to 100 parts by weight (based on solid content) of an acrylic resin (Samwon, AT-2100), 500 parts by weight of spherical aluminum nitride (Tokuyama, average particle diameter 5 탆) (Sigma Aldrich, thickness: long diameter ratio 1:10, average long diameter 5 占 퐉) 300 parts by weight were charged and stirred for 1 hour. Thereafter, 0.5 part by weight of an isocyanate-based thermosetting agent (Samwon, CAT-45) was added and stirred for 1 hour to prepare a pressure-sensitive adhesive composition.

The pressure-sensitive adhesive composition was coated on one surface of a silicone type release film (XD5BR, 38 탆) of a silicone release film (XD5BR, 38 탆) at a thickness of about 40 탆 and dried at 130 캜 for 3 minutes (thermosetting) ) Was applied to produce a pressure-sensitive adhesive sheet.

≪ Comparative Example 1 &

300 parts by weight of methyl isobutyl ketone was added to 100 parts by weight (based on solid content) of an acrylic resin (Samwon, AT-2100), 500 parts by weight of spherical aluminum nitride (Tokuyama, average particle size 1 μm) and spherical silver (Sigma Aldrich, Particle diameter 1 mu m) were added and stirred for 1 hour. Thereafter, 0.5 part by weight of an isocyanate-based thermosetting agent (Samwon, CAT-45) was added and stirred for 1 hour to prepare a pressure-sensitive adhesive composition.

The pressure-sensitive adhesive composition was coated on one surface of a silicone type release film (XD5BR, 38 탆) of a silicone release film (XD5BR, 38 탆) at a thickness of about 40 탆 and dried at 130 캜 for 3 minutes (thermosetting) ) Was applied to produce a pressure-sensitive adhesive sheet.

≪ Comparative Example 2 &

300 parts by weight of methyl isobutyl ketone was added to 100 parts by weight (based on solid content) of an acrylic resin (Samwon, AT-2100) and 500 parts by weight of spherical aluminum nitride (Tokuyama, average particle size 1 탆) (Sigma Aldrich, thickness: long diameter ratio 1:20, average long diameter 8 占 퐉) 300 parts by weight were charged and stirred for 1 hour. Thereafter, 0.5 part by weight of an isocyanate-based thermosetting agent (Samwon, CAT-45) was added and stirred for 1 hour to prepare a pressure-sensitive adhesive composition.

The pressure-sensitive adhesive composition was coated on one surface of a silicone type release film (XD5BR, 38 탆) of a silicone release film (XD5BR, 38 탆) at a thickness of about 40 탆 and dried at 130 캜 for 3 minutes (thermosetting) ) Was applied to produce a pressure-sensitive adhesive sheet.

≪ Comparative Example 3 &

300 parts by weight of methyl isobutyl ketone was added to 100 parts by weight (based on solid content) of an acrylic resin (Samwon, AT-2100), 500 parts by weight of spherical aluminum nitride (Tokuyama, average particle diameter 1 μm) and spherical alumina (DENKA, 0.7 mu m) was added and stirred for 1 hour. Thereafter, 0.5 part by weight of an isocyanate-based thermosetting agent (Samwon, CAT-45) was added and stirred for 1 hour to prepare a pressure-sensitive adhesive composition.

The pressure-sensitive adhesive composition was coated on one surface of a silicone type release film (XD5BR, 38 탆) of a silicone release film (XD5BR, 38 탆) at a thickness of about 40 탆 and dried at 130 캜 for 3 minutes (thermosetting) ) Was applied to produce a pressure-sensitive adhesive sheet.

≪ Comparative Example 4 &

300 parts by weight of methyl isobutyl ketone was added to 100 parts by weight (based on solid content) of an acrylic resin (Samwon, AT-2100), 800 parts by weight of spherical aluminum nitride (Tokuyama, average particle size 1 μm) and spherical alumina (DENKA, 0.7 mu m) were added and stirred for 1 hour. Thereafter, 0.5 part by weight of an isocyanate-based thermosetting agent (Samwon, CAT-45) was added and stirred for 1 hour to prepare a pressure-sensitive adhesive composition.

The pressure-sensitive adhesive composition was coated on one surface of a silicone type release film (XD5BR, 38 탆) of a silicone release film (XD5BR, 38 탆) at a thickness of about 40 탆 and dried at 130 캜 for 3 minutes (thermosetting) ) Was applied to produce a pressure-sensitive adhesive sheet.

≪ Comparative Example 5 &

300 parts by weight of methyl isobutyl ketone was added to 100 parts by weight (based on solid content) of an acrylic resin (Samwon, AT-2100) and 500 parts by weight of spherical aluminum nitride (Tokuyama, average particle diameter 1 μm) and boron nitride (LOWER FRICTION, Average long diameter 1.5 占 퐉, thickness: long diameter ratio 1: 8), and the mixture was stirred for 1 hour. Thereafter, 0.5 part by weight of an isocyanate-based thermosetting agent (Samwon, CAT-45) was added and stirred for 1 hour to prepare a pressure-sensitive adhesive composition.

The pressure-sensitive adhesive composition was coated on one surface of a silicone type release film (XD5BR, 38 탆) of a silicone release film (XD5BR, 38 탆) at a thickness of about 40 탆 and dried at 130 캜 for 3 minutes (thermosetting) ) Was applied to produce a pressure-sensitive adhesive sheet.

The properties of the pressure-sensitive adhesive sheets according to Examples 1 to 3 and Comparative Examples 1 to 5 were measured through the following experimental examples, and the results are shown in Table 3 below.

[Experimental Example]

1. Thermal conductivity [W / mK]

The thermally conductive pressure-sensitive adhesive compositions of Examples and Comparative Examples were dried on a Teflon-made dish (diameter 8 cm), dispensed so that the thickness of the sample became 1 mm, and dried at 40 ° C for 8 hours using a vacuum oven. Respectively. The sample thus prepared was measured at 25 DEG C using NETZSCH LFA447 under the following conditions, and the thermal conductivity of the sample was measured.

- ASTME 1461 / DIN EN821

2. Delamination Area ratio

A pressure sensitive adhesive sheet having a size of 3 cm x 3 cm was placed on one surface of the slide glass so that the pressure sensitive adhesive surface was in contact with the pressure sensitive adhesive sheet, and then pressed (1.2 MPa, 5 sec) at room temperature using a press machine (Daegu Precision, Hot press). After pressing, the sample was cured in a hot air oven at 170 DEG C for 1 hour, and the opposite surface of the slide glass with the adhesive was observed with an optical microscope to measure the area ratio of the portion where delamination occurred.

3. Whether it is delamination

A pressure sensitive adhesive sheet having a size of 3 cm x 3 cm was placed between a metal SUS having a size of 4 cm x 4 cm and a silicon wafer having a size of 4 cm x 4 cm and compressed at room temperature using a press machine (Daegu Precision, Hot press) ). After compression, the specimen is cured in a hot air oven at 170 ° C for 1 hour and then immersed in an ethanol solution in which red dye is dissolved for 1 hour. After 1 hour, the sample was taken out and the metal SUS and the silicon wafer were disassembled, and it was confirmed whether or not the dye penetrated between the substrate and the pressure-sensitive adhesive. The criteria are shown in Table 1 below.

Judgment division Judgment method X No red dye marks △ Dye penetration was observed at the edges. ○ Dye penetration to the middle part was observed.

4.Imprint Evaluation

An adhesive tape is applied to the lead frame (Cu) Two rounds of lamination were carried out at room temperature using a 2 kg roller. Thereafter, the pressure-sensitive adhesive tape was peeled off, and the imprint strength of the pressure-sensitive adhesive surface was observed with a microscope and evaluated based on the criteria shown in Table 2 below.

Judgment division Judgment method River Imprint is very clear medium Imprint appears about Imprint hardly appears

Thermal conductivity [W / mk] Delamination area ratio [%] Whether it is delamination Imprint rating Example 1 1.8 2.1 x River Example 2 2.1 7.1 x River Example 3 2.2 9.0 x River Comparative Example 1 1.2 2.5 x River Comparative Example 2 1.3 6.5 x River Comparative Example 3 1.0 2.2 x River Comparative Example 4 1.6 23 ○ about Comparative Example 5 1.2 11 △ about

As can be seen from Table 3, the adhesive sheets according to Examples 1 to 3 of the present invention satisfy all the main requirements.

However, for Comparative Examples 1 to 3, the properties such as delamination area ratio and delamination were satisfied, but the thermal conductivity was relatively low. In the case of Comparative Example 4, the thermal conductivity satisfied the required properties, but did not satisfy the delamination properties. In the case of Comparative Example 5, both the thermal conductivity and the delamination properties were not satisfied.

More specifically, in the case of Comparative Example 1, as a result of injecting the spherical particles, it is expected that when the spherical particles are mixed with the tabular particles, the expected probability of contact between the particles is low and the thermal conductivity is not improved.

In the case of Comparative Example 2, it is expected that the plate-like phase is physically excessively deformed to increase the probability of contact between the particles, so that the heat conduction can not be made directionally and the heat is scattered and the thermal conductivity is lowered.

In the case of Comparative Example 3, spherical alumina having a lower thermal conductivity than spherical particles was introduced, and as a result, the thermal conductivity was lower than that of Comparative Example 1.

In the case of Comparative Example 4, although the thermal conductivity was greatly improved as a result of increasing the content of the thermally conductive filler, the flexibility of the pressure-sensitive adhesive layer was lowered and many delaminations occurred in the substrate, failing to satisfy required properties.

Finally, in the case of Comparative Example 5, the probability of contacting the particles with each other was increased by using the plate-shaped boron nitride particles, and the thermal conductivity was improved, but the thermal conductivity of the plate-like particles was lower than that of the particles, I did.

It is to be understood that the present invention is not limited to the above embodiments and various changes and modifications may be made by those skilled in the art without departing from the spirit and scope of the invention.

11, 11 ': substrate film
12: pressure-sensitive adhesive layer
21: Concrete metal filler
22: Plate metal filler (thickness: long diameter ratio = 1: 8)

Claims (8)

(B) having a Young's modulus of 10 (10) to 20 (10), wherein the thermoplastic resin (B) has a Young's modulus of 10 Wherein the spherical metal particles having a Young's modulus of 100 GPa are physically deformed in a spherical shape into a plate by collision with ceramic beads having a Young's modulus of 150 to 200 GPa. delete The method according to claim 1,
The spherical filler (A) is selected from metal, ceramic and carbon materials having a Young's modulus of 250 to 600 GPa. delete The method according to claim 1,
Wherein the sheet-like filler (B) has a thickness-to-length ratio of 1: 3 to 1:10. The method according to claim 1,
(A) and 100 to 400 parts by weight of the sheet-like filler (B), based on 100 parts by weight of the acryl-based resin, 0.3 to 10 parts by weight of the thermosetting agent, 200 to 700 parts by weight of the spherical filler Composition. A pressure-sensitive adhesive layer formed from the thermoconductive pressure-sensitive adhesive composition according to any one of claims 1 to 7;
Wherein the pressure-sensitive adhesive layer comprises a base film applied on both sides of the pressure-sensitive adhesive layer. 8. The method of claim 7,
Wherein the thickness of the pressure-sensitive adhesive layer is 10 占 퐉 to 100 占 퐉.

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