KR20110085214A - Thermosetting silicone composition for light emitting diode encapsulant - Google Patents

Abstract

PURPOSE: A thermosetting silicone composition is provided to secure strong mechanical properties and high adhesive property without use of filler lowering optical tansmissivity, and to maintain the shape of the thermosetting silicone composition even in an additional heat process and the continued exposition to the heat. CONSTITUTION: A thermosetting silicone composition for a light emitting diode encapsulant comprises (a) a silicone resin including an organic group including at least two carbon-carbon double bonds, (b) a hardener including at least two hydrogens bonded to the silicon atoms, (c) additional reaction catalysts, (d) alcohols including a carbon-carbon triple bond, and (e) organic additives including an ester group. The linear expansion coefficient is 100-300 ppm/K.

Description

Thermosetting Silicone Composition for Light Emitting Diode Encapsulant

The present invention relates to a thermosetting silicone composition for light emitting diode encapsulant.

The light emitting diode (hereinafter referred to as "light emitting device") industry is a technology-intensive industry that requires expensive equipment and specialized personnel, high initial investment, and long-term technology accumulation. The light emitting device is a component that is applied to most industries, and its range is extended to electronic signs, traffic lights, automotive lamps, or LCD BLU (Back light units). As a conventional encapsulation material applied to such a light emitting device, epoxy resin is It has been widely used. Epoxy resins have been used in LEDs as well as semiconductors for a long time due to their high adhesion and strong mechanical properties.

The light emitting device of the past has been used for a long time because the epoxy itself does not have a great influence on the reliability because the luminance and heat generation are not high. However, in the high performance / high brightness field based on the blue / white light emitting device, the encapsulating material is actually used. Increasing the amount of heat generated by yellowing or high brightness of the glass requires long-lasting durability, making it impossible to cope with conventional epoxy resins.

As the required material level in the light emitting device field where light is generated and high heat is raised, the demand for a new material, that is, a silicon material, is continued. Silicon is a material with a siloxane bond called Si—O—Si— in the main chain. The bond energy of this siloxane bond is 10 ⁶ kcal / mol, and compared with the CC bond which is the main chain of general organic polymer, it is 20 kcal / mol or more and it is very stable. Therefore, it can be said that the material has excellent weather resistance, heat resistance, electrical insulation, and chemical stability compared to general organic materials. In addition, since it has a very high light transmittance up to the visible-ultraviolet region, the silicon material is a very suitable material as a material for a light emitting device that is left in a difficult environment.

However, silicon has poor adhesion and mechanical properties compared to the conventional epoxy type encapsulant, and has a limitation as a light emitting device material that requires long-term reliability due to its relatively high coefficient of linear expansion. On the other hand, the filler used to lower the coefficient of linear expansion may reduce the transparency of the encapsulant may reduce the overall light extraction efficiency of the light emitting device.

Therefore, the thermosetting silicone composition for a light emitting device encapsulation material of the present invention has an object to secure improved adhesion and low coefficient of linear expansion while satisfying the conditions of high brightness and high heat resistance without using a filler.

The present inventors lower the linear expansion coefficient, secure strong mechanical properties and adhesive strength without using a filler to increase the light extraction efficiency of the light emitting device and secure long-term reliability, and secure a suitable viscosity for the function as a potting agent to be mixed with the phosphor Efforts have been made to develop this easy silicone encapsulant. As a result, the present invention was completed by not only securing strong mechanical properties and adhesive strength without using a filler that lowers the light transmittance, but also maintaining the shape even after further thermal processing and continuous heat exposure with a low coefficient of linear expansion. .

Accordingly, an object of the present invention is to provide a thermosetting silicone composition for a LED encapsulant.

Other objects and advantages of the present invention will become apparent from the following detailed description and claims.

According to one aspect of the invention, the present invention (a) a silicone resin comprising an organic group comprising at least two carbon-carbon double bonds; (b) a curing agent comprising at least two hydrogens bonded to silicon atoms; (c) an addition reaction catalyst; (d) alcohols comprising carbon-carbon triple bonds; And (e) an organic additive comprising an ester group, the thermal expansion silicone composition for a LED encapsulant having a linear expansion coefficient of 100-300 ppm / K.

The present inventors lower the linear expansion coefficient, secure strong mechanical properties and adhesive strength without using a filler to increase the light extraction efficiency of the light emitting device and secure long-term reliability, and secure a suitable viscosity for the function as a potting agent to be mixed with the phosphor Efforts have been made to develop this easy silicone encapsulant. As a result, a silicone encapsulant was developed that not only secures strong mechanical properties and adhesion without using a filler that lowers light transmittance, but also maintains its shape even in a further thermal process and continuous heat exposure with a low coefficient of linear expansion.

The silicon composition for semiconductor die bonding of the present invention is basically (a) a silicone resin comprising an organic group including at least two carbon-carbon double bonds; (b) a curing agent comprising at least two hydrogens bonded to silicon atoms; (c) an addition reaction catalyst; (d) alcohols comprising carbon-carbon triple bonds; And (e) an organic additive comprising an ester group.

The silicone resin included in the present invention also includes any silicone resin used to manufacture a light emitting diode encapsulant in the art. Silicone resin suitable for the present invention is a silicone resin comprising an organic group containing at least two carbon-carbon double bonds, preferably the silicone resin is a polyorgano comprising a Q-unit of the following formula (1) Siloxane, a polyorganosiloxane not containing a Q-unit of Formula 1, a solid polyorganosiloxane comprising a Q-unit of Formula 1, and an M-unit of Formulas 2 and 3, a polyhedral polyorganosiloxane, and At least one selected from the group consisting of mixtures thereof:

Formula 1

Formula 2

In the M-unit of Formula 2, R ¹ is a monovalent hydrocarbon group that does not include an alkenyl group,

Formula 3

In the M-unit of Formula 3, R ¹ is a monovalent hydrocarbon group not including an alkenyl group, and R ² is an alkenyl group.

In the above formula, the monovalent hydrocarbon group that does not contain an alkenyl group is an alkyl, alkoxy, aryl or aralkyl group, preferably an alkyl group.

The term "alkyl" group here means a straight or pulverized saturated hydrocarbon group, preferably a C ₁ -C ₁₀ alkyl group, more preferably a C ₁ -C ₄ straight or branched alkyl group, which is lower alkyl, methyl, ethyl , n -propyl, isopropyl, isobutyl, n -butyl, t -butyl, pentyl, hexyl and heptyl, most preferably methyl. The term “alkoxy” means an —Oalkyl group. Preferably, the alkoxy group comprises methoxy or ethoxy.

The term “aryl” means a wholly or partially unsaturated substituted or unsubstituted monocyclic or polycyclic carbon ring, preferably monoaryl or biaryl, more preferably substituted or unsubstituted phenyl, Naphthyl, tolyl and xylyl, most preferably the aryl is phenyl.

The term “alkenyl group” refers to a straight or pulverized unsaturated hydrocarbon group having a specified carbon number, preferably C ₂ -C ₆ straight or branched chain alkenyl, which is a hydrocarbon group having 2 to 6 carbon atoms having at least one double bond. More preferably, they are ethenyl, propenyl, isopropenyl, butenyl, isobutenyl, t -butenyl, n -pentenyl, n -hexenyl and vinyl groups, and most preferably a vinyl group.

According to a more preferred embodiment of the present invention, the polyorganosiloxane comprising the Q-unit of Formula 1 of the present invention comprises the Q-unit of Formula 1 and the M-units of Formulas 2 and 3, R ² of the M-unit of 3 is a vinyl group, most preferably dimethylvinylsiloxy terminal 4 functional polyorganosiloxane.

According to a more preferred embodiment of the present invention, the polyorganosiloxane comprising the Q-unit of Formula 1 included in the composition of the present invention has a vinyl group content of 0.01-0.8 mmole / g, 5-65% Of Q-units, most preferably a vinyl group content of 0.2-0.5 mmole / g and 22-45% of Q-units.

According to still another preferred embodiment of the present invention, the polyorganosiloxane comprising the Q-unit of the formula (1) included in the composition of the present invention has a polyvinyl chloride having a viscosity of 600-1000 cP and 7,000-11,000 cP. Organosiloxanes are used. The reason for using a polyorganosiloxane with a difference in viscosity is that the viscosity varies depending on the molecular length of the main chain, which affects the degree of crosslinking and furthermore, the coefficient of linear expansion. That is, short molecules of polyorganosiloxane having a viscosity of 600-1000 cP are located between relatively long molecules having a viscosity of 7,000-11,000 cP to form a dense structure.

According to another preferred embodiment of the present invention, the polyorganosiloxane that does not include the Q-unit of Formula 1 included in the composition of the present invention is a linear type as a polyorganosiloxane including other units than the Q-unit. (linear type) polyorganosiloxane, most preferably dimethylvinylsiloxy terminal polyorganosiloxane.

According to another preferred embodiment of the present invention, the solid polyorganosiloxane comprising the Q-unit of Formula 1 and the M-units of Formulas 2 and 3 included in the composition of the present invention is represented by the following general formula (1) Solid polyorganosiloxanes are:

Formula 1

OH _a R ² _b R ¹ _c SiO _{(4-abc) / 2}

In General Formula 1, R ¹ is a monovalent hydrocarbon group that does not contain an alkenyl group, R ² is an alkenyl group, and a + b + c is smaller than 3 and greater than zero.

In the above formula, the monovalent hydrocarbon group which does not contain an alkenyl group is an alkyl, alkoxy, aryl or aralkyl group, preferably an alkyl group, more preferably methyl, ethyl, n -propyl, isopropyl, isobutyl, n − Butyl, t -butyl, pentyl, hexyl and heptyl, most preferably methyl. The alkenyl group is preferably C ₂ -C ₆ straight or branched alkenyl, which is a hydrocarbon group having 2 to 6 carbon atoms having at least one double bond, more preferably ethenyl, propenyl, isopropenyl, Butenyl, isobutenyl, t -butenyl, n -pentenyl, n -hexenyl and vinyl groups, most preferably vinyl groups.

Most preferably, the solid polyorganosiloxane comprising the Q-unit of Formula 1 and the M-units of Formulas 2 and 3 included in the composition of the present invention is a tetrafunctional vinyl terminated solid silicone resin. .

According to another preferred embodiment of the present invention, the polyhedral polysiloxane included in the composition of the present invention is a polysiloxane represented by the following general formula (2):

Formula 2

^{_{(R 3 SiO 3/2)}} n

In Formula 2, R ³ is a monovalent hydrocarbon group selected from the group consisting of alkyl, alkoxy, alkenyl, aryl, and hydroxyl groups.

Preferably, in Formula 2, R ³ is a mixture of an alkyl group and an alkenyl group, more preferably a C ₁ -C ₄ alkyl group and an alkenyl group, most preferably a methyl group and at least two vinyl groups. The polyhedral polyorganosiloxane may be included in the composition of the present invention for improving mechanical properties, and most preferably poly (propylmethacryl-heptaisobutylsilsesquioxane) -co- (n-butylmethacryl) Eight).

According to a preferred embodiment of the present invention, the silicone resin comprising an organic group comprising the at least two carbon-carbon double bonds included in the composition of the present invention (i) the Q-unit of the formula (unit) A polyorganosiloxane comprising; and (ii) a solid polyorganosiloxane comprising a Q-unit of formula (1) and an M-unit of formulas (2) and (3), more preferably of (iii) and (ii) The ratio is 6-9: 4-1. That is, in the case of a mixture of the components (iii) and (ii), (iii) a polyorganosiloxane comprising a Q-unit of the formula (1) is included as a subject.

According to another preferred embodiment of the present invention, the silicone resin comprising an organic group including the at least two carbon-carbon double bonds included in the composition of the present invention (i) the Q-unit of the formula (unit) It is a polyorganosiloxane and (ii) polyhedron type polyorganosiloxane containing, More preferably, the ratio of the said (iii) and (ii) component is 6-9.5: 4-0.5. That is, in the case of a mixture of the components (iii) and (ii), (iii) a polyorganosiloxane comprising a Q-unit of the formula (1) is included as a subject.

Since the polyorganosiloxane including the Q-unit of the formula (unit) is included as a subject, it is possible to secure strong mechanical properties, low linear expansion coefficient and high adhesion without using a filler.

The curing agent included in the composition of the present invention includes various curing agents known in the art commonly used in silicone encapsulants, and includes at least two hydrogens bonded to silicon atoms. Preferably, the curing agent is an organohydrogenpolysiloxane selected from at least one member selected from the group consisting of

Formula 3

^{_{R 1 3 SiO 1/2 (}} R 1 HSiO 1/2) n R 1 3 SiO 1/2

Formula 4

^{_{R 1 2 HSiO 1/2 (}} R 1 HSiO 1/2) m R 1 2 HSiO 1/2

Formula 5

^{_{R 1 2 HSiO 1/2 (}} R 1 2 SiO 1/2) p R 1 2 HSiO 1/2

In said general formula, R <^1> is monovalent hydrocarbon group which does not contain an alkenyl group.

In the above general formula, the monovalent hydrocarbon group containing no alkenyl group is an alkyl, alkoxy, aryl or aralkyl group, preferably an alkyl group, more preferably methyl, ethyl, n -propyl, isopropyl, isobutyl, n − Butyl, t -butyl, pentyl, hexyl and heptyl, most preferably methyl.

The curing agent comprising at least two hydrogens bonded to the silicon atoms included in the composition of the present invention preferably contains at least two Si-H bonds in the terminal or molecule and thus the carbon- of the component (a) silicone resin. It may react with the carbon double bond to form a crosslinked structure.

The organohydrogenpolysiloxane represented by the general formula (3) is preferably trimethylsiloxy-terminated methylhydrogenpolysiloxane, and the organohydrogenpolysiloxane represented by the general formula (5) is preferably dimethylhydrogensiloxy-terminated dimethylpolysiloxane. to be. SiH content of the curing agent is 0.1-10.0 mmole / g, the SiH content to 1 mole of vinyl group has a content ratio of 1-2 mole.

The addition reaction catalyst contained in the composition of the present invention is a catalyst for promoting hydrosilylation addition reaction between the carbon-carbon double bond in the silicone resin as component (a) and the SiH group in the curing agent as component (b). It is a platinum group metal catalyst, More preferably, it is a platinum catalyst, a palladium type catalyst, or a rhodium type catalyst, Most preferably, it is a platinum divinyl composite. Preferably, the addition reaction catalyst is blended in the range of 1-200 ppm, more preferably 5-50 ppm, based on the weight of the silicone resin as component (a).

One of the greatest features of the present invention is that it achieves improved adhesion and low coefficient of linear expansion while satisfying the conditions of high brightness and high heat resistance without including filler in the composition of the present invention.

Alcohols including carbon-carbon triple bonds included in the composition of the present invention include various alcohols known in the art, which serve to prevent aggregation of the coupling agent to induce uniform dispersion. Preferably, the alcohol containing the carbon-carbon triple bond is ethynyl cyclo hexanol.

The organic additive including the ester group included in the composition of the present invention has mechanical properties and anti-blocking agent properties, and is preferably a compound represented by the following Chemical Formula 4:

Formula 4

R ¹ -COO-R ²

In Formula 4, R ¹ And Each R ² is independently an alkyl group.

Alkyl groups are preferably methyl, ethyl, n -propyl, isopropyl, isobutyl, n -butyl, t -butyl, pentyl, hexyl and heptyl groups, and more preferably methyl groups.

Dimethyl ester is preferable as the organic additive including the ester group.

According to another preferred embodiment of the present invention, the composition of the present invention based on the entire thermosetting silicone composition for light emitting diode encapsulant (a) a silicone resin 40 comprising an organic group containing at least two carbon-carbon double bonds -98 weight percent; (b) 1-30% by weight of a curing agent comprising at least two hydrogens bonded to silicon atoms; (c) 0.01-10% by weight of addition reaction catalyst; (d) 0.01-10% by weight of an alcohol comprising a carbon-carbon triple bond; And (e) 0.01-10% by weight of an organic additive comprising an ester group, more preferably (a) 65-95% by weight of a silicone resin comprising an organic group comprising at least two carbon-carbon double bonds; (b) 3-20% by weight of a curing agent comprising at least two hydrogens bonded to silicon atoms; (c) 0.1-5% by weight of addition reaction catalyst; (d) 0.1-5% by weight alcohol containing carbon-carbon triple bonds; And (e) 0.1-5% by weight of an organic additive comprising an ester group, most preferably (a) 76-93% by weight of a silicone resin comprising an organic group comprising at least two carbon-carbon double bonds; (b) 5.9-15% by weight of a curing agent comprising at least two hydrogens bonded to silicon atoms; (c) 0.3-3 weight percent of addition reaction catalyst; (d) 0.3-3% by weight alcohol containing carbon-carbon triple bonds; And (e) 0.5-3% by weight of an organic additive comprising an ester group.

The thermosetting silicone composition for LED encapsulant of the present invention may further include a silane coupling agent, and an alkoxy group silane compound is preferable as the silane coupling agent, and more preferably vinyl group, glycidyl group, styryl group, methacryl group. , An alkoxy silane compound in which a functional group selected from an acryl group, a ureido group, a chloroalkyl group, a mercapto group, an isocyanate group, an amino group, a dimethylamino group, an imidazole group, an acetoacetate group and an epoxy group is further substituted, and most preferably a vinyl tree Ethoxysilane, Vinyltrimethoxysilane, Vinyltriacetoxysilane, Vinyltri (2-methoxyethoxy) silane, N- (3-acryloxy-2-hydroxypropyl) -3-aminopropyltriethoxy Silane, 3-methacryloxypropyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, N-phenylaminopropyltrimethoxysilane, N- (2- Minoethyl) -3-aminopropylmethyldimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropyltris (2-ethyl Methoxy) silane, 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-chloropropyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, (3 -Glycidoxypropyl) methyldiethoxysilane, 3-glycidoxypropyltrimethoxysilane, bis [3- (triethoxysilyl) propyl] tetrasulfide or mixtures thereof.

The content of the silane coupling agent in the composition of the present invention is 0.1-10 parts by weight, more preferably 0.2-5 parts by weight, most preferably based on 100 parts by weight of the composition comprising the above components (a) to (e). Preferably 0.4-1 part by weight.

In addition to the components (a) to (e), the composition of the present invention optionally contains an oxidative stabilizer, a reaction controlling agent for controlling reactivity and pot life, and a silicon in addition to the polyorganosiloxane described above for controlling hardness and adhesion. Various additives, such as linear or cyclic low molecular organosiloxane of about 2-10 atoms, can be added selectively within the range which does not impair the effect of this invention.

The content of the oxidative stabilizer as an additive included in the composition of the present invention is 0.01-10 parts by weight, more preferably 0.03-5 parts by weight based on 100 parts by weight of the composition containing the above components (a) to (e). And most preferably 0.05-1 part by weight.

In order to apply the composition of the present invention to a light emitting diode, it is applied by mixing and potting with a phosphor in a light emitting diode packaging process. In this case, a suitable viscosity and a thixotropic index (TI) are required. Has a viscosity and TI suitable for this. Preferably the composition of the present invention has a viscosity at 5.0 rpm of 1,000-4,000 cps, and has a thixotropic coefficient (TI) value of 1.0-2.0.

The composition of the present invention has a low coefficient of linear expansion, prevention of deterioration of transparency and improved adhesion even without using a filler. Preferably the coefficient of linear expansion has a value of 100-300 ppm / K, more preferably 200-290 ppm / K.

According to a preferred embodiment of the present invention, the composition of the present invention has a decrease in light transmittance after ultraviolet irradiation to light transmittance after curing of 0.5-5%.

According to another preferred embodiment of the present invention, the composition of the present invention has a decrease in light transmittance after heat exposure to light transmittance after curing of 0.5-3.5%.

The features and advantages of the present invention are summarized as follows:

(a) The thermosetting silicone composition for an LED encapsulant of the present invention is applied in a mixing and potting manner with a phosphor in a light emitting diode packaging process, and has a suitable viscosity and thixotropic index (TI) value.

(a) The composition of the present invention has strong mechanical properties, low linear expansion coefficient of 300 ppm / K or less, and high adhesion without using a filler by using a silicone resin containing an organic group as a main ingredient.

(c) As a result, the light extraction efficiency and reliability of the light emitting diode are ensured so that the light transmittance is maintained even after long-term exposure to heat and ultraviolet irradiation to maintain the performance of the light emitting diode.

Hereinafter, the present invention will be described in more detail with reference to Examples. These examples are only for illustrating the present invention in more detail, and the scope of the present invention is not limited by these examples in accordance with the gist of the present invention to those skilled in the art. Will be self explanatory.

Example

Example 1

The thermosetting silicone composition for a LED encapsulant of the present invention was prepared in the following composition:

Raw material name Part ratio(%) Remarks Dimethylvinylsiloxy terminal 4 functional polysiloxane 1 65 89.60 Vinyl Group Content: 0.230 mmole / g
Viscosity: 800 cP 4 quardri-functional
Vinyl Terminal Silicone Resin (Solid) 35  Vinyl group content: 0.19 mmole / g Trimethylsiloxy terminated methylhydrogenpolysiloxane 6 5.376  SiH content: 7.5 mmole / g Dimethylhydrogensiloxy terminated dimethylpolysiloxane 3 2.69  SiH content: 4.2mmole / g Dimethyl ester One 0.900  Sigma-aldrich Ethynylcyclohexanol 0.5 0.448  Sigma-aldrich Platinum divinyl composite 0.5 0.448  UCT Inc. Vinyltrimethoxysilane 0.5 0.448  Gelest Oxidation stabilizer
(Tris (2,4-ditert-butylphenyl) phosphite) 0.1 0.090  IRGAFOS 168 Gross weight 111.6 100 -

Example  2

The thermosetting silicone composition for a LED encapsulant of the present invention was prepared in the following composition:

Raw material name Part ratio(%) Remarks Dimethylvinylsiloxy terminal 4 functional polysiloxane 1 50 89.60 Vinyl Group Content: 0.230 mmole / g
Viscosity: 800 cP Dimethylvinylsiloxy terminal 4 functional polysiloxane 2 30 Vinyl Group Content: 0.213 mmole / g
Viscosity: 9,000 cP 4 quardri-functional
Vinyl Terminal Silicone Resin (Solid) 20  Vinyl group content: 0.19 mmole / g Trimethylsiloxy terminated methylhydrogenpolysiloxane 6 5.38  SiH content: 7.5 mmole / g Dimethylhydrogensiloxy terminated dimethylpolysiloxane 3 2.69  SiH content: 4.2 mmole / g Dimethyl ester One 0.90  Sigma-aldrich Ethynylcyclohexanol 0.5 0.45  Sigma-aldrich Platinum divinyl composite 0.5 0.45  UCT Inc. Vinyltrimethoxysilane 0.25 0.22  Gelest Acryloxytriethoxysilane 0.25 0.22  Gelest Oxidation stabilizer
(Tris (2,4-ditert-butylphenyl) phosphite) 0.1 0.09  IRGAFOS 168 Gross weight 111.6 100% -

Example  3

A thermosetting silicone composition for a LED encapsulant of the present invention was prepared in the following composition:

Raw material name Part ratio(%) Remarks Dimethylvinylsiloxy terminal 4 functional polysiloxane 1 50 89.60 Vinyl Group Content: 0.230 mmole / g
Viscosity: 800 cP Dimethylvinylsiloxy terminal 4 functional polysiloxane 2 30 Vinyl Group Content: 0.213 mmole / g
Viscosity: 9,000 cP Poly (propylmethacryl-heptaisobutylsilsesquioxane) -co- (n-butylmethacrylate) 5 Vinyl Group Content: 0.230 mmole / g
Viscosity: 800 cP 4 quardri-functional
Vinyl Terminal Silicone Resin (Solid) 15  Vinyl group content: 0.19 mmole / g Trimethylsiloxy terminated methylhydrogenpolysiloxane 6 5.38  SiH content: 7.5 mmole / g Dimethylhydrogensiloxy terminated dimethylpolysiloxane 3 2.69  SiH content: 4.2 mmole / g Dimethyl ester One 0.90  Sigma-aldrich Ethynylcyclohexanol 0.5 0.45  Sigma-aldrich Platinum divinyl composite 0.5 0.45  UCT Inc. Vinyltrimethoxysilane 0.25 0.22  Gelest Acryloxytriethoxysilane 0.25 0.22  Gelest Oxidation stabilizer
(Tris (2,4-ditert-butylphenyl) phosphite) 0.1 0.09  IRGAFOS 168 Gross weight 111.6 100% -

Experimental Example  One

Various properties of the thermosetting silicone composition for LED encapsulant of the present invention prepared in the above embodiment were analyzed, and the results are shown in Table 4:

Analysis item Example 1 Example 2 Example 3 Viscosity (cps) ^{1 )} at 5.0 rpm 2,000 ± 500 3,300 ± 500 2,500 ± 500 TI ^{1 )} 1.10 ± 0.1 1.13 ± 0.1 1.11 ± 0.1 Curing condition ^{2 )} 100 ℃ / 1hr
+ 150 ° C / 1hr 100 ℃ / 1hr
+ 150 ° C / 1hr 100 ℃ / 1hr
+ 150 ° C / 1hr Appearance after hardening ^{3 )} transparent
(colorless transparent) transparent transparent Light transmittance After curing ^{4 )} 96.5 95 93 UV aging ^{5 )} 94.6 94.1 88.5 Thermal aging ^{6 )} 94.5 94.1 90.0 Mechanical property Hardness (Shore A) ⁷ ) 72 65 68 Coefficient of linear expansion ^{8 )} 220 285 280 Adhesion ^{9 )} Shear stress > 2.5 kg > 3.5.kg > 3.2 kg Standard Deviation
(Standard: within 25%) satisfied satisfied satisfied Fracture surface Void X X X

Property analysis in Table 4 was performed as follows:

1) Viscosity and TI (thixotropic index): It measured at 25 degreeC using the cone and plate type Brookfield viscometer (HBDV II + / CP51, Brookfield). TI was calculated by dividing the viscosity value at 0.5 rpm by the viscosity value at 5.0 rpm.

2) Curing condition: Proceed to step cure and harden in oven under the condition of 100 ℃ / 1hr + 150 ℃ / 1hr. At this time, the temperature increase rate was 10 degreeC per minute.

3) Appearance after hardening: Poured into a mold having a thickness of 2 mm, and cured under the above curing conditions, the change of the properties was visually observed.

4) Light transmittance after curing: Pour into a mold of 2 mm thick coated with a release agent and cure under the above curing conditions, and then use a UV-VIS spectrophotometer (Lambda 35, PerkinElmer) equipped with an integrating sphere. Measured.

The measurements proceed in the ultraviolet-visible region, 300-800 nm, with the results read at 400, 450, 500, 550 or 600 nm, and Table 4 above shows the light transmittance at 450 nm as a representative value.

5) Light transmittance after UV aging: The light transmittance after curing was irradiated with an intensity of 20 W / cm ² with a UV lamp of 365 nm, and then measured in the same manner as the light transmittance measurement method. Each irradiation time was compared with the light transmittance after curing.

6) Light transmittance after thermal aging: After light curing, the sample was measured at 150 ° C. for 1,000 hr, and then measured in the same manner as the light transmittance measurement method. The measured value was compared with the light transmittance after curing.

7) Hardness (Shore A): It was poured into a mold having a thickness of 2 mm coated with a releasing agent, and cured according to the above curing conditions.

8) Linear Expansion Coefficient: Pour into a mold of 2 mm thick coated with a release agent and cure under the above curing conditions, and measure the change in thermal expansion coefficient with temperature using a MettlerToledo TMA device. At this time, the measurement was carried out in expansion mode, and the result value was calculated for the coefficient of linear expansion from 25 ° C. to 150 ° C. for comparison.

9) Void and adhesive strength: After curing using the curing conditions as described above by measuring the shear strength (Shear Strength) using the adhesion test equipment (Dage 4000 series / 100kg cartridge, Dage) at room temperature and 260 ℃ temperature The void formation and the adhesive force of the fracture surface were evaluated. In Table 4, room temperature adhesive strength of the silver plated pad is representatively specified.

As can be seen in Table 4, the composition of the present invention exhibits excellent properties as a light emitting diode encapsulant composition. The composition of the present invention exhibits a viscosity in the range of 2,000 cP to 4,000 cP, which is suitable for application in a mixing and potting manner with phosphors in light emitting diode packaging processes. In addition, thixotropic index (TI), which is one of important physical properties, satisfies the range of 1.0 to 2.0, and is very advantageous for being applied to a light emitting diode device by a potting method.

As shown in Table 4, the biggest feature of the silicone composition of the present invention is that the coefficient of linear expansion shows a value of 300 ppm / K or less even without using a filler. This property provides stability to the continuous heat applied in a number of thermal processes and in actual use in light emitting diode packaging processes using the silicone composition of the present invention.

In addition, the silicone composition of the present invention exhibits a light transmittance of 5% or less even when exposed to UV or heat, and this property makes it very advantageous to maintain long-term performance of a light emitting diode device using the silicone composition of the present invention.

Finally, the silicone composition of the present invention exhibits a low standard deviation of 25% or less in terms of adhesion, and this property is due to the effective dispersion of the coupling agent by an anti-blocking agent. Provides performance uniformity of light emitting diode devices.

Having described the specific part of the present invention in detail, it is apparent to those skilled in the art that such a specific technology is only a preferred embodiment, and the scope of the present invention is not limited thereto. Thus, the substantial scope of the present invention will be defined by the appended claims and equivalents thereof.

Claims (19)

(a) a silicone resin comprising an organic group comprising at least two carbon-carbon double bonds; (b) a curing agent comprising at least two hydrogens bonded to silicon atoms; (c) an addition reaction catalyst; (d) alcohols comprising carbon-carbon triple bonds; And (e) an organic additive comprising an ester group, wherein the linear expansion coefficient has a value of 100-300 ppm / K.
The thermosetting silicone composition of claim 1, wherein the coefficient of linear expansion is 200-290 ppm / K.
The thermosetting silicone composition of claim 1, wherein the composition has a viscosity at 5.0 rpm of 1,000-4,000 cps.
The thermosetting silicone composition of claim 1, wherein the composition has a thixotropy coefficient (TI) value of 1.0-2.0.
2. The thermosetting silicone composition for light emitting diode encapsulation material according to claim 1, wherein the composition has a decrease in light transmittance after ultraviolet irradiation with respect to light transmittance after curing is 0.5-5%.
2. The thermosetting silicone composition for light emitting diode encapsulation according to claim 1, wherein the composition has a decrease in light transmittance after heat exposure to light transmittance after curing of 0.5 to 3.5%.
According to claim 1, wherein the silicone resin comprising an organic group containing at least two carbon-carbon double bond is a polyorganosiloxane comprising a Q-unit of the following formula (1), Q- of the following formula (1) Minimum from the group consisting of polyorganosiloxanes not containing units, solid polyorganosiloxanes comprising Q-units of formula (1) and M-units of formulas (2) and (3), polyhedral polyorganosiloxanes, and mixtures thereof A thermosetting silicone composition for light emitting diode encapsulant, characterized in that at least one kind is selected:
Formula 1

(2)

In the M-unit of Formula 2, R ¹ is a monovalent hydrocarbon group that does not include an alkenyl group,
(3)

In the M-unit of Formula 3, R ¹ is a monovalent hydrocarbon group not including an alkenyl group, and R ² is an alkenyl group.
According to claim 7, wherein the polyorganosiloxane comprising a Q-unit of Formula 1 comprises a Q-unit of Formula 1 and M-units of Formulas 2 and 3, R of the M-unit of Formula 3 ² is a vinyl group, the thermosetting silicone composition for light-emitting diode encapsulant.
The method of claim 8, wherein the polyorganosiloxane comprising a Q-unit of Formula 1 has a vinyl group content of 0.01-0.8 mmole / g, and comprises 5-65% of the Q-unit Thermosetting silicone composition for diode encapsulant.
8. The light emitting diode according to claim 7, wherein the solid polyorganosiloxane comprising the Q-unit of Formula 1 and the M-units of Formulas 2 and 3 is a solid polyorganosiloxane represented by the following general formula (1): Thermosetting Silicone Compositions for Encapsulants:
Formula 1
OH _a R ² _b R ¹ _c SiO _{(4-abc) / 2}
In the general formula (3), R ¹ is a monovalent hydrocarbon group not containing an alkenyl group, R ² is an alkenyl group, and a + b + c is smaller than 3 and larger than zero.
8. The thermosetting silicone composition of claim 7, wherein the polyhedral polysiloxane is a polysiloxane represented by the following general formula (2):
Formula 2
_{^{(R 3 SiO 3/2)}} n
In Formula 4, R ³ is a monovalent hydrocarbon group selected from the group consisting of alkyl, alkoxy, alkenyl, aryl and hydroxyl groups.
According to claim 7, wherein the silicone resin comprising an organic group comprising at least two carbon-carbon double bonds (i) a polyorganosiloxane comprising a Q-unit of Formula 1 and (ii) The thermosetting silicone composition for LED encapsulant, characterized in that the solid polyorganosiloxane comprising the Q-unit of Formula 1 and the M-units of Formulas 2 and 3.
According to claim 7, wherein the silicone resin comprising an organic group comprising at least two carbon-carbon double bonds (i) a polyorganosiloxane comprising a Q-unit of Formula 1 and (ii) A thermosetting silicone composition for light emitting diode encapsulant, comprising a polyhedral polyorganosiloxane.
The thermosetting silicone composition of claim 1, wherein the curing agent is at least one organohydrogenpolysiloxane selected from the group consisting of the following Formulas 3 to 5.
Formula 3
_{^{R 1 3 SiO 1/2 (}} R 1 HSiO 1/2) n R 1 3 SiO 1/2
Formula 4
_{^{R 1 2 HSiO 1/2 (}} R 1 HSiO 1/2) m R 1 2 HSiO 1/2
Formula 5
_{^{R 1 2 HSiO 1/2 (}} R 1 2 SiO 1/2) p R 1 2 HSiO 1/2
In said general formula, R <^1> is monovalent hydrocarbon group which does not contain an alkenyl group.
The thermosetting silicone composition according to claim 1, wherein the addition reaction catalyst is a platinum group metal catalyst selected from the group consisting of platinum, palladium and rhodium.
The thermosetting silicone composition of claim 1, wherein the organic additive including the ester group is a compound represented by the following Chemical Formula 4.
Formula 4
R ¹ -COO-R ²
In Formula 4, R ¹ And Each R ² is independently an alkyl group.
The thermosetting silicone composition of claim 1, wherein the alcohol containing a carbon-carbon triple bond is ethynylcyclohexanol.
The composition of claim 1, wherein the composition is vinyltriethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, vinyltri (2-methoxyethoxy) silane, N- (3-acryloxy-2-hydrate Roxypropyl) -3-aminopropyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, N-phenylaminopropyltrimethoxysilane , N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropyl Tris (2-ethylethoxy) silane, 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-chloropropyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltri Methoxysilane, (3-glycidoxypropyl) methyldiethoxysilane, 3-glycidoxypropyltrimethoxysilane, bis [3- (triethoxysilyl) propyl] tetrasul A thermosetting silicone composition for light emitting diode encapsulant, further comprising a silane coupling agent selected from the group consisting of a feed and a mixture thereof.
The thermosetting silicone composition of claim 1, wherein the composition is applied in a light emitting diode packaging process by mixing and potting with phosphors.