JP2011086844A - Die bonding material for light emitting diode - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a die bonding material for a light emitting diode which can obtain a cured body high in hardness, excellent in heat resistance and transparency, and superior in light permeability in a low-wavelength range, and which can stably perform a highly reliable wire bonding. <P>SOLUTION: The die bonding material for the light emitting diode is characterized in comprising an addition reaction curing type silicone resin composition such that the content of non-functional low-molecular siloxane having a vapor pressure of ≥0.5 mmHg at 150°C in the cured body is ≤300 ppm. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a die bond material useful for die bonding of a light emitting diode (hereinafter referred to as “LED”) element.

  Conventionally, an epoxy resin is used as a sealing material for LED elements and a die bonding material (that is, an adhesive for bonding a die such as an LED element and a substrate such as a package). In particular, if the resin is too soft in the die bond material, there is a problem that bonding cannot be performed in the wire bonding process performed after the die bond process. Have been used. However, when used for blue LEDs, white LEDs, etc., the sealing material and die bond material made of epoxy resin may be yellowed by strong ultraviolet rays and absorb light. There is a problem.

  In recent years, expectations for the durability of LEDs have further increased, and the sealing material of LED elements has been replaced by epoxy resins having good durability instead of epoxy resins. Like the sealing material, the die bond material is also required to have durability. Further, it is expected that the die bond material is required to further improve the heat resistance as well as the luminance. There is a possibility that more LEDs will be used in the future from the viewpoint of glossiness.

From such a viewpoint, a die bond material using a silicone resin has been developed. However, the silicone die bond material usually contains a low molecular siloxane. The silicone die bond material needs to be heat-cured after the semiconductor element is mounted on the substrate. At this time, the low molecular siloxane is volatilized and adheres to the surface of the semiconductor element to cover it thinly. For this reason, problems are likely to occur in the next wire bonding step, and it is difficult to stably perform highly reliable wire bonding.
In addition, the following literature is mentioned as a prior art relevant to this invention.

JP 2006-342200 A JP 2007-63299 A

  The present invention has been made in view of the above circumstances, and can provide a cured product having high hardness, excellent heat resistance, transparency, and light transmittance in a low wavelength region, and having high reliability. An object of the present invention is to provide a die bonding material capable of stably performing wire bonding.

  As a result of intensive studies to achieve the above object, the present inventors have found that a non-functional low molecular siloxane having a vapor pressure of not less than 0.5 mmHg at 150 ° C. in a cured product of an addition reaction curable silicone resin composition. (Cyclic or linear siloxane having a degree of polymerization of 10 or less) Using a silicone resin composition having a content of 300 ppm or less as a die-bonding material has high hardness, heat resistance, transparency, and light transmission in a low wavelength region. The present inventors have found that a cured product having excellent properties can be provided and that reliable wire bonding can be stably performed, and the present invention has been completed.

Accordingly, the present invention provides the following die bond material for light emitting diodes.
[Claim 1]
A die-bonding material for a light-emitting diode, comprising an addition-reaction curable silicone resin composition having a non-functional low-molecular siloxane content of 300 ppm or less having a vapor pressure of 0.5 mmHg or more at 150 ° C. in a cured product.
[Claim 2]
The addition reaction curable silicone resin composition is
(A) Linear organopolysiloxane having at least two alkenyl groups bonded to silicon atoms in one molecule and having a viscosity at 25 ° C. of 1,000 mPa · s or less: 50 to 10 parts by mass (B) Average composition formula (1):
(R ² ₃ SiO _1/2 ) _k (R ¹ R ² ₂ SiO _1/2 ) _m (R ¹ R ² SiO) _n (R ² ₂ SiO) _p
(R ¹ SiO _3/2 ) _q (R ² SiO _3/2 ) _r (SiO _4/2 ) _s (1)
(Wherein R ¹ independently represents an alkenyl group, R ² independently represents an unsubstituted or substituted monovalent hydrocarbon group not containing an aliphatic unsaturated bond, provided that at least 80 mol% of all R ^{2 s)} Is a methyl group, and k, m, n, p, q, r and s are k ≧ 0, m ≧ 0, n ≧ 0, p ≧ 0, q ≧ 0, r ≧ 0 and s ≧ 0, respectively. (However, m + n + q> 0, q + r + s> 0, and k + m + n + p + q + r + s = 1).
A three-dimensional network-like organopolysiloxane resin that is waxy or solid at 23 ° C .: 50 to 90 parts by mass (provided that the total of the component (A) and the component (B) is 100 parts by mass. )
(C) The following average composition formula (2):
R ³ _a H _b SiO _{(4-ab) / 2} (2)
(In the formula, R ³ independently represents an unsubstituted or substituted monovalent hydrocarbon group that does not contain an aliphatic unsaturated bond, provided that at least 50 mol% of all R ³ is a methyl group; (7 ≦ a ≦ 2.1, b is a number satisfying 0.001 ≦ b ≦ 1.0, where a + b is a number satisfying 0.8 ≦ a + b ≦ 3.0.)
And an organohydrogenpolysiloxane having at least two hydrogen atoms bonded to a silicon atom in one molecule: (C) component with respect to all silicon atom-bonded alkenyl groups in component (A) and component (B) 2. The die bond material according to claim 1, comprising an amount of hydrogen atoms bonded to silicon atoms in the amount of 0.5 to 5.0 times mol and (D) a platinum group metal catalyst: an effective amount. .

  The die-bonding material of the present invention has a non-functional low molecular siloxane content of 300 ppm or less having a vapor pressure of 0.5 mmHg or higher at 150 ° C. in a cured product, can suppress contamination on the surface of a semiconductor element, and has high reliability. Bonding can be performed stably.

The die bond material used in the present invention is composed of an addition reaction curable silicone resin composition having a non-functional low molecular siloxane content of 300 ppm or less having a vapor pressure of 0.5 mmHg or more at 150 ° C. in a cured product. . In this case, as the addition reaction curable silicone resin composition, those containing the following components (A) to (D) are preferably used.
(A) Linear organopolysiloxane having at least two alkenyl groups bonded to silicon atoms in one molecule and having a viscosity at 25 ° C. of 1,000 mPa · s or less: 50 to 10 parts by mass (B) Average composition formula (1):
(R ² ₃ SiO _1/2 ) _k (R ¹ R ² ₂ SiO _1/2 ) _m (R ¹ R ² SiO) _n (R ² ₂ SiO) _p
(R ¹ SiO _3/2 ) _q (R ² SiO _3/2 ) _r (SiO _4/2 ) _s (1)
(Wherein R ¹ independently represents an alkenyl group, R ² independently represents an unsubstituted or substituted monovalent hydrocarbon group not containing an aliphatic unsaturated bond, provided that at least 80 mol% of all R ^{2 s)} Is a methyl group, and k, m, n, p, q, r and s are k ≧ 0, m ≧ 0, n ≧ 0, p ≧ 0, q ≧ 0, r ≧ 0 and s ≧ 0, respectively. (However, m + n + q> 0, q + r + s> 0, and k + m + n + p + q + r + s = 1).
A three-dimensional network-like organopolysiloxane resin that is waxy or solid at 23 ° C .: 50 to 90 parts by mass (provided that the total of the component (A) and the component (B) is 100 parts by mass. )
(C) The following average composition formula (2):
R ³ _a H _b SiO _{(4-ab) / 2} (2)
(In the formula, R ³ independently represents an unsubstituted or substituted monovalent hydrocarbon group that does not contain an aliphatic unsaturated bond, provided that at least 50 mol% of all R ³ is a methyl group; (7 ≦ a ≦ 2.1, b is a number satisfying 0.001 ≦ b ≦ 1.0, where a + b is a number satisfying 0.8 ≦ a + b ≦ 3.0.)
And an organohydrogenpolysiloxane having at least two hydrogen atoms bonded to a silicon atom in one molecule: (C) component with respect to all silicon atom-bonded alkenyl groups in component (A) and component (B) Amount in which hydrogen atoms bonded to silicon atoms in the catalyst are 0.5 to 5.0 times mol, and (D) platinum group metal catalyst: effective amount

  Hereinafter, each component of the composition will be described in detail. In the present specification, “Me” represents a methyl group, and “Vi” represents a vinyl group.

<(A) component>
(A) A component is a component for bringing stress relaxation after hardening of a composition. The component (A) has at least 2, preferably 2 to 10, more preferably 2 to 5, alkenyl groups bonded to silicon atoms, and a viscosity at 25 ° C. of 1,000 mPa · s or less. (Usually 1 to 1,000 mPa · s), preferably 700 mPa · s or less (for example, 5 to 700 mPa · s), usually the main chain is composed of repeating diorganosiloxane units, and both ends of the molecular chain are triorgano It is an organopolysiloxane having an essentially linear molecular structure blocked with a siloxy group. When the viscosity exceeds 1,000 mPa · s, this component functions as a soft segment more than necessary, making it difficult to obtain a target high hardness.
In the present invention, the viscosity is a value measured with a rotational viscometer (hereinafter the same).

The alkenyl group bonded to the silicon atom usually has 2 to 8 carbon atoms, preferably 2 to 4 carbon atoms. Specific examples thereof include a vinyl group, an allyl group, a butenyl group, a pentenyl group, a hexenyl group, and a heptenyl group, and a vinyl group is preferable.
The alkenyl group bonded to the silicon atom may exist in either the molecular chain terminal or the molecular chain non-terminal (that is, the molecular chain side chain) in the molecule of the organopolysiloxane of component (A), or these Although it may exist in both, it exists at least at the both ends of a molecular chain.

  In the organopolysiloxane molecule of component (A), the organic group bonded to the silicon atom other than the alkenyl group is not particularly limited as long as it does not have an aliphatic unsaturated bond. The monovalent hydrocarbon group usually has 1 to 12 carbon atoms, preferably 1 to 10 carbon atoms. Examples of the unsubstituted or substituted monovalent hydrocarbon group include alkyl groups such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, and a heptyl group; a cycloalkyl group such as a cyclohexyl group; Aryl groups such as a group, tolyl group, xylyl group and naphthyl group; aralkyl groups such as a benzyl group and a phenethyl group; some or all of hydrogen atoms of these groups are halogen atoms such as a chlorine atom, a fluorine atom and a bromine atom Substituted halogenated alkyl groups such as chloromethyl group, 3-chloropropyl group, 3,3,3-trifluoropropyl group and the like can be mentioned, preferably an alkyl group, more preferably a methyl group, 80 mol% or more, more preferably 90 mol% or more, particularly preferably 98 mol% or more of a substituent other than an alkenyl group is a methyl group. Preferred.

The organopolysiloxane of component (A) is represented, for example, by the following average composition formula (3).
R ⁴ _c R ⁵ _d SiO _{(4-cd) / 2} (3)
(Wherein R ⁴ is an unsubstituted or substituted monovalent hydrocarbon group independently having no aliphatic unsaturated bond, R ⁵ is independently an alkenyl group, and c is from 1.9 to 2.1. The number d is a number from 0.005 to 1.0, provided that c + d satisfies 1.95 to 3.0.

In the above average composition formula (3), the unsubstituted or substituted monovalent hydrocarbon group having no aliphatic unsaturated bond represented by R ⁴ is exemplified as an organic group bonded to a silicon atom other than the alkenyl group. It is the same kind of thing. In addition, the alkenyl group represented by R ⁵ is the same as that exemplified as the alkenyl group bonded to the silicon atom.
c is preferably a number of 1.95 to 2.00, d is preferably a number of 0.01 to 0.5, and c + d preferably satisfies 1.98 to 2.5.

Examples of the organopolysiloxane of component (A) include those represented by the following general formulas (4) to (10).
ViR ⁶ ₂ SiO (R ⁶ ₂ SiO) _e SiR ⁶ ₂ Vi (4)
ViR ⁶ ₂ SiO (R ⁶ ViSiO) _f (R ⁶ ₂ SiO) _g SiR ⁶ ₂ Vi (5)
Vi ₂ R ⁶ SiO (R ⁶ ₂ SiO) _e SiR ⁶ Vi ₂ (6)
Vi ₃ SiO (R ⁶ ₂ SiO) _e SiVi ₃ (7)
Vi ₂ R ⁶ SiO (R ⁶ ViSiO) _f (R ⁶ ₂ SiO) _g SiR ⁶ Vi ₂ (8)
Vi ₃ SiO (R ⁶ ViSiO) _f (R ⁶ ₂ SiO) _g SiVi ₃ (9)
R ⁶ ₃ SiO (R ⁶ ViSiO) _f (R ⁶ ₂ SiO) _g SiR ⁶ ₃ (10)
(Wherein R ⁶ independently represents an unsubstituted or substituted monovalent hydrocarbon group not containing an aliphatic unsaturated bond, e is an integer of 0 to 200, preferably 3 to 120, and f is 1 to 10, Preferably it is an integer of 1-5, g is an integer of 0-200, preferably 3-110.

In the general formulas (4) to (10), the unsubstituted or substituted monovalent hydrocarbon group represented by R ⁶ preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms. is there. Specific examples thereof include those exemplified as organic groups bonded to silicon atoms other than the alkenyl groups, preferably the same as those other than aryl groups and aralkyl groups, but the light resistance and heat resistance of the cured product. Is more preferably an alkyl group, particularly preferably a methyl group.

等が挙げられる。
（Ａ）成分は、一種単独で用いても二種以上を併用してもよい。 As a specific example of the component (A),

Etc.
(A) A component may be used individually by 1 type, or may use 2 or more types together.

  This component (A) is usually prepared by equilibrating cyclopolysiloxane with a strongly basic catalyst such as potassium hydroxide, tetraalkylammonium hydroxide, tetraalkylphosphonium hydroxide, or a siliconate compound thereof, A polymer is obtained by neutralization and deactivation, and a low-molecular siloxane (degree of polymerization (that is, the number of silicon atoms in one molecule) of 10 or less cyclic or linear siloxane) by-product generated at this time, Usually removed by a strip under reduced pressure. Although these removal levels depend on economics, currently commercially available materials have a non-functional low molecular siloxane content in the molecule with a vapor pressure of 0.5 mmHg or higher at 150 ° C. of thousands to tens of thousands. It is in the range of ppm. By reducing this non-functional low molecular siloxane content to 300 ppm or less, preferably 200 ppm or less, the non-functional low molecular siloxane content having a vapor pressure of 0.5 mmHg or more at 150 ° C. in the cured product of the composition. , 300 ppm or less was confirmed. Therefore, in the present invention, the content of non-functional low-molecular siloxane having a vapor pressure of 0.5 mmHg or more at 150 ° C. in the component (A) by strengthening the strip or cleaning with a solvent is 300 ppm or less, more preferably 200 ppm. It is recommended to prepare so that:

<(B) component>
The component (B) is a component for obtaining reinforcing properties while maintaining the transparency of the cured product. The component (B) is represented by the following average composition formula (1) and is waxy or solid at 23 ° C., and in the molecule, an alkenyl group bonded to a silicon atom, a trifunctional siloxane unit and / or SiO _{4. This is} a three-dimensional network-like organopolysiloxane resin that essentially contains ₂ units. “Waxy” means a gum (raw rubber) that shows no self-fluidity at 23 ° C. of 10,000,000 mPa · s or more, particularly 100,000,000 mPa · s or more. .

(R ² ₃ SiO _1/2 ) _k (R ¹ R ² ₂ SiO _1/2 ) _m (R ¹ R ² SiO) _n (R ² ₂ SiO) _p
(R ¹ SiO _3/2 ) _q (R ² SiO _3/2 ) _r (SiO _4/2 ) _s (1)
(Wherein R ¹ independently represents an alkenyl group, R ² independently represents an unsubstituted or substituted monovalent hydrocarbon group not containing an aliphatic unsaturated bond, provided that at least 80 mol% of all R ^{2 s)} Is a methyl group, and k, m, n, p, q, r and s are k ≧ 0, m ≧ 0, n ≧ 0, p ≧ 0, q ≧ 0, r ≧ 0 and s ≧ 0, respectively. (However, m + n + q> 0, q + r + s> 0, and k + m + n + p + q + r + s = 1).

In the average composition formula (1), the alkenyl group represented by R ¹ is the same as that exemplified as the alkenyl group bonded to the silicon atom in the component (A), but is easily available and priced. A vinyl group is preferable from the viewpoint.

The monovalent hydrocarbon group not containing an aliphatic unsaturated bond represented by R ² is the same as that exemplified as the organic group bonded to the silicon atom other than the alkenyl group in the component (A). at least 80 mol% of R ² (80 to 100 mole%), typically 90 to 100 mol%, more typically 98 to 100 mol% are methyl groups. When the proportion of methyl groups is less than 80 mol% of the total R ² , the composition becomes cloudy because of incompatibility with the component (A), and the desired highly transparent cured product is obtained. There may not be.

  k is 0 to 0.65, m is 0 to 0.65, n is 0 to 0.5, p is 0 to 0.5, q is 0 to 0.8, r is 0 to 0.8, s is The number is preferably 0 to 0.6. Further, m + n + q is preferably a number of 0.1 to 0.8, particularly 0.2 to 0.65, and q + r + s is a number of 0.1 to 0.8, particularly 0.2 to 0.6. It is preferable.

  In the component (B), the content of the alkenyl group bonded to the silicon atom is preferably in the range of 0.01 to 1 mol, and in the range of 0.05 to 0.5 mol, per 100 g of the component (B). Is more preferable. When the content of the alkenyl group satisfies the range of 0.01 to 1 mol, the crosslinking reaction proceeds sufficiently, and a cured product with higher hardness can be obtained.

The organopolysiloxane resin of component (B) is, for example,
(R ² ₃ SiO _1/2 ) _k (R ¹ R ² ₂ SiO _1/2 ) _m (SiO _4/2 ) _s ,
(R ¹ R ² ₂ SiO _1/2 ) _m (SiO _4/2 ) _s ,
(R ¹ R ² SiO) _n (R ² ₂ SiO) _p (R ² SiO _3/2 ) _r ,
(R ¹ R ² ₂ SiO _1/2 ) _m (R ² ₂ SiO) _p (R ¹ SiO _3/2 ) _q ,
(R ¹ R ² ₂ SiO _1/2 ) _m (R ² ₂ SiO) _p (R ² SiO _3/2 ) _r ,
(R ² ₃ SiO _1/2 ) _k (R ¹ R ² ₂ SiO _1/2 ) _m (R ² ₂ SiO) _p (R ² SiO _3/2 ) _r ,
(R ² ₃ SiO _1/2 ) _k (R ¹ R ² ₂ SiO _1/2 ) _m (R ² ₂ SiO) _p (R ¹ R ² SiO) _n (R ² SiO _3/2 ) _r
(Wherein R ¹ , R ² , k, m, n, p, q, r, and s are as defined in the average composition formula (1).)
The thing represented by these is preferable.

As a specific example of the component (B),
(Me ₃ SiO _1/2 ) _0.4 (ViMe ₂ SiO _1/2 ) _0.1 (SiO _4/2 ) _0.5 ,
(ViMeSiO) _0.4 (Me ₂ SiO) _0.15 (MeSiO _3/2 ) _0.45 ,
(ViMe ₂ SiO _1/2 ) _0.2 (Me ₂ SiO) _0.25 (MeSiO _3/2 ) _0.55
Etc.
(B) A component may be used individually by 1 type, or may use 2 or more types together.

The ratio of the component (A) to the component (B) is one of the important factors in the above composition. The blending amount of the component (B) is preferably 50 to 90 parts by mass (50 to 10 parts by mass as the component (A)) with respect to 100 parts by mass in total of the component (A) and the component (B) More preferably, it is 60-80 mass parts (40-20 mass parts as (A) component), More preferably, it is 65-75 mass parts (35-25 mass parts as (A) component). When the blending amount of the component (B) is less than 50 parts by mass (the component (A) is 50 parts by mass or more), the target high hardness may not be obtained and exceeds 90 parts by mass ((A) In the case where the component is less than 10 parts by mass), the viscosity of the composition becomes remarkably high, and it may be difficult to use the composition as a die bond material for an LED element.
The component (B) is itself waxy or solid at 23 ° C., but is mixed with the component (A) to become a uniform liquid. For workability, a component (B) dissolved in a soluble solvent such as toluene or xylene may be used.

  Since the component (B) is produced by hydrolyzing the raw material chlorosilane or alkoxysilane, the low-molecular siloxane (cyclic or linear siloxane having a polymerization degree of 10 or less) by-product generated at this time is usually It is removed by strips under reduced pressure. Although these removal levels depend on economics, currently commercially available materials have a non-functional low molecular siloxane content in the molecule with a vapor pressure of 0.5 mmHg or higher at 150 ° C. of thousands to tens of thousands. It is in the range of ppm. By reducing this non-functional low molecular siloxane content to 300 ppm or less, preferably 200 ppm or less, the non-functional low molecular siloxane content having a vapor pressure of 0.5 mmHg or more at 150 ° C. in the cured product is 300 ppm or less. It was confirmed that Therefore, in the present invention, the content of the non-functional low-molecular siloxane having a vapor pressure of 0.5 mmHg or higher at 150 ° C. in the component (B) is 300 ppm or less, more preferably 200 ppm or less, as in the component (A). It is recommended to prepare as follows.

<(C) component>
The component (C) acts as a crosslinking agent that crosslinks with the alkenyl group in the component (A) and the component (B) by a hydrosilylation reaction and dilutes the composition to a viscosity suitable for the intended use. It is a component that works as well. The component (C) is represented by the following average composition formula (2), and has at least two hydrogen atoms (that is, SiH groups) bonded to silicon atoms in one molecule (usually 2 to 200), preferably 3 It is an organohydrogenpolysiloxane having at least one (for example, about 3 to 100).

R ³ _a H _b SiO _{(4-ab) / 2} (2)
(In the formula, R ³ independently represents an unsubstituted or substituted monovalent hydrocarbon group that does not contain an aliphatic unsaturated bond, provided that at least 50 mol% of all R ³ is a methyl group; (7 ≦ a ≦ 2.1, b is a number satisfying 0.001 ≦ b ≦ 1.0, where a + b is a number satisfying 0.8 ≦ a + b ≦ 3.0.)

In the above average composition formula (2), the unsubstituted or substituted monovalent hydrocarbon group not containing an aliphatic unsaturated bond represented by R ³ is an organic compound bonded to a silicon atom other than an alkenyl group in the component (A). but it is of the same type exemplified as groups, at least 50 mole% of the total R ^3, typically from 60 to 100 mol% are methyl groups. When the proportion of methyl groups is less than 50 mol% of the total R ³ , the compatibility with the component (A) and the component (B) is inferior, and the problem of cloudiness or phase separation of the composition occurs. There is.
It is preferable that a is 1.0 to 2.0, b is 0.01 to 1.0, and a + b is 1.1 to 2.6.

  In the component (C), the content of hydrogen atoms bonded to the silicon atom is preferably in the range of 0.001 to 0.02 mol, and in the range of 0.002 to 0.017 mol, per gram of the component (A). It is more preferable that

  Hydrogen atoms bonded to silicon atoms contained in two or more, preferably three or more in one molecule (that is, SiH groups) may be located either at the end of the molecular chain or in the middle of the molecular chain. It may be located in both. The molecular structure of the organohydrogenpolysiloxane may be any of linear, cyclic, branched, and three-dimensional network structures, but the number of silicon atoms in one molecule (or the degree of polymerization) is usually 2 to 400, preferably 3 to 200, and more preferably about 4 to 100.

  The organohydrogenpolysiloxane of component (C) has a viscosity at 25 ° C. of preferably 1,000 mPa · s or less (usually 1 to 1,000 mPa · s), more preferably 5 to 200 mPa · s.

（式中、Ｒ³は前記のとおりであり、ｈは５〜４０の整数、ｉは５〜２０の整数、ｊは２〜３０の整数である。）
で表されるもの等が例示される。 Specific examples of the component (C) organohydrogenpolysiloxane include 1,1,3,3-tetramethyldisiloxane, 1,3,5,7-tetramethylcyclotetrasiloxane, tris (hydrogen Dimethylsiloxy) methylsilane, tris (hydrogendimethylsiloxy) phenylsilane, methylhydrogencyclopolysiloxane, methylhydrogensiloxane / dimethylsiloxane cyclic copolymer, both ends trimethylsiloxy group-blocked methylhydrogenpolysiloxane, both ends trimethylsiloxy Group-blocked dimethylsiloxane / methylhydrogensiloxane copolymer, both ends dimethylhydrogensiloxy group-blocked dimethylpolysiloxane, both ends dimethylhydrogensiloxy group-blocked dimethylsiloxa・ Methyl hydrogen siloxane copolymer, both ends trimethylsiloxy group-blocked methyl hydrogen siloxane ・ Diphenyl siloxane copolymer, both ends trimethylsiloxy group-blocked methyl hydrogen siloxane ・ Diphenyl siloxane ・ dimethyl siloxane copolymer, both ends trimethylsiloxy Blocked methylhydrogensiloxane / methylphenylsiloxane / dimethylsiloxane copolymer, both ends dimethylhydrogensiloxy group-blocked methylhydrogensiloxane / dimethylsiloxane / diphenylsiloxane copolymer, both ends dimethylhydrogensiloxy group-blocked methylhydrogen Siloxane / dimethylsiloxane / methylphenylsiloxane copolymer, (CH ₃ ) ₂ HSiO _1/2 unit and (CH ₃ ) ₃ SiO _1/2 unit Copolymers consisting of units and SiO _4/2 units, copolymers consisting of (CH ₃ ) ₂ HSiO _1/2 units and SiO _4/2 units, (CH ₃ ) ₂ HSiO _1/2 units and SiO _{4 / 2} units and a copolymer composed of (C ₆ H ₅ ) ₃ SiO _1/2 units, and the following general formulas (11) and (12):
R ³ ₃ SiO [SiR ³ (H) O] _t SiR ³ ₃ (11)
Cyclic [SiR ³ (H) O] _u (12)
(In the formula, R ³ is as described above, t is an integer of 2 to 30, preferably 2 to 25, and u is an integer of 4 to 8.)
Represented by the following general formula:

(In the formula, R ³ is as described above, h is an integer of 5 to 40, i is an integer of 5 to 20, and j is an integer of 2 to 30.)
What is represented by etc. is illustrated.

Specific examples of the component (C) include the following general formula (13):
Me ₃ SiO [SiMe (H) O] _t SiMe ₃ (13)
(Wherein t is as described above.)
And those represented by the following average structural formula.

（Ｃ）成分は、一種単独で用いても二種以上を併用してもよい。

(C) A component may be used individually by 1 type, or may use 2 or more types together.

  Component (C) is blended in an amount of 0.5 to 5 hydrogen atoms bonded to silicon atoms in component (C) relative to alkenyl groups bonded to all silicon atoms in components (A) and (B). It is preferable that the amount is 0.0 mol, more preferably 0.7 to 3.0 mol. In the case where the blending amount does not satisfy the amount of 0.5 to 5.0 moles, the balance of crosslinking may be inappropriate.

  In a preferred embodiment, the blending amount of the component (C) is such that the hydrogen atom bonded to the silicon atom in the component (C) is 0.6 to 0.6 with respect to the alkenyl group bonded to all silicon atoms in the composition. The amount is preferably 3.0 times mole, and more preferably 0.7 to 2.0 times mole. When this range is satisfied, a composition having a viscosity range suitable for use and a desired cured product having high hardness can be obtained.

<(D) component>
The platinum group metal catalyst as component (D) is a component for proceeding and promoting the hydrosilylation reaction of the components (A) to (C).
The platinum group metal catalyst is not particularly limited. For example, platinum group metals such as platinum, palladium, rhodium; chloroplatinic acid, alcohol-modified chloroplatinic acid, coordination of chloroplatinic acid and olefins, vinylsiloxane or acetylene compound Examples include platinum compounds such as compounds, platinum group metal compounds such as tetrakis (triphenylphosphine) palladium, chlorotris (triphenylphosphine) rhodium, etc., and compatibility with the components (A) to (C) is good. Since it contains almost no chloro impurities, it is preferably a chloroplatinic acid modified with silicone.
(D) A component may be used individually by 1 type, or may use 2 or more types together.

  (D) The compounding quantity of a component should just be an effective amount as a catalyst, However, Usually, 3-100 ppm in conversion of the mass of a platinum group metal element with respect to the sum total of (A)-(C) component, Preferably 5-40 ppm. If this blending amount is appropriate, the hydrosilylation reaction can be promoted more effectively.

<Other ingredients>
In addition to the components (A) to (D), the above composition may contain other components exemplified below as long as the object of the present invention is not impaired.

Examples of other components include thixotropic control agents such as fumed silica; light scattering agents such as crystalline silica; reinforcing materials such as fumed silica and crystalline silica; colorants such as titanium oxide; alumina and crystallinity. Silica and other thermally conductive fillers; phosphors; petroleum solvents, viscosity modifiers such as non-reactive silicone oils that do not have reactive functional groups; silane coupling agents, epoxy groups, alkoxy groups, bonded to silicon atoms Adhesion improvers such as silicone compounds other than the components (A) to (C) having at least one alkenyl group such as a hydrogen atom (ie, SiH group) and a vinyl group bonded to a silicon atom; silver, gold, etc. Conductivity imparting agents such as metal powders; pigments and dyes for coloring; reaction inhibitors such as tetramethyltetravinyltetracyclosiloxane and acetylene alcohol.
These other components may be used alone or in combination of two or more.
Among these, it has at least one of alkenyl groups such as a silane coupling agent, an epoxy group, an alkoxy group, a hydrogen atom bonded to a silicon atom (ie, SiH group), and a vinyl group bonded to a silicon atom (A) to (C) It is preferable to mix | blend adhesive improvement agents, such as a silicone compound other than a component, for adhesive improvement, and the compounding quantity in the case of mix | blending is 100 mass parts in total of a component (A)-(C) normally. It is 0.1-10 mass parts with respect to.

  80 mol of all monovalent hydrocarbon groups ((A) component, (B) component, (C) component all monovalent hydrocarbon groups) bonded to silicon atoms other than aliphatic unsaturated bonds in the above composition % Or more (80 to 100 mol%), particularly 90 mol% or more (90 to 100 mol%) is a methyl group, because it is excellent in heat resistance and light resistance (ultraviolet resistance). It is preferable because of its excellent resistance to deterioration including discoloration due to stress.

<Preparation and curing of composition>
-Preparation method The above composition can be prepared by mixing the components (A) to (D) and optionally other components. For example, the composition is composed of a part comprising the components (A) and (B). , (C) component, (D) component and optionally other parts composed of other components may be prepared separately, and then the two parts may be mixed.

Curing conditions The composition may be cured under known conditions and is cured at room temperature, but is preferably cured by heating, for example, by heating at 60 to 180 ° C. for 10 minutes to 5 hours. . In particular, the Shore D hardness of a cured product obtained by curing the composition is preferably 30 or more, particularly preferably 50 or more. The curing conditions for setting the Shore D hardness to 30 or more are usually the above-mentioned compositions. Can be obtained by heating and curing at 120 to 180 ° C., for example, for 30 minutes to 5 hours.

-Die bonding-
In the present invention, the silicone resin composition (die bond material) obtained above is applied to a substrate, an optical semiconductor element is placed on the surface to be coated on the substrate, and then the die bond material is heated and cured. .
Examples of the substrate to be used include a lead frame and a package.
Examples of the optical semiconductor element include an LED element and a light receiving element.
As an example of a method for die-bonding an optical semiconductor element using a die-bonding material, the die-bonding material is filled in a syringe and applied to a substrate such as a package to a thickness of 5 to 100 μm using a dispenser. Thereafter, there is a method in which an optical semiconductor element is die-bonded on a substrate by placing an element on the applied die-bonding material and curing the die-bonding material.

-Wire bonding-
The wire bonding method itself is not particularly limited, and any generally known method may be used.

In the present invention, a non-functional low molecular siloxane having a vapor pressure of 0.5 mmHg or more at 150 ° C. in the die-bonded material, that is, a cured product of the silicone resin composition (degree of polymerization (that is, silicon atoms in one molecule). Number) 10 or less cyclic or linear siloxane) content is 300 ppm or less, preferably 200 ppm or less. When the content of such non-functional low molecular siloxane exceeds 300 ppm, the low molecular siloxane adversely affects the LED during wire bonding.
In the present invention, “non-functional” means that the organic group bonded to the silicon atom is non-reactive, for example, an alkyl group, an aryl group, or an aralkyl group, and is typically a low molecular weight cyclic group. Or it is a linear dimethylpolysiloxane. Since the alkenyl group is addition-reactive, it is not included in “non-functional”.

  Such a cured product having a non-functional low molecular siloxane content of 300 ppm or less contains a non-functional low molecular siloxane having a vapor pressure of 0.5 mmHg or more at 150 ° C. in the molecule as components (A) and (B) as described above. It can be achieved by using a component whose amount is reduced to 300 ppm or less, preferably 200 ppm or less. Here, as the method for reducing the content of non-functional low molecular siloxane having a vapor pressure of 0.5 mmHg or higher at 150 ° C. in the molecule as the components (A) and (B) as described above, a solvent extraction method, A vacuum strip method, a thin-film distillation method, a combination of two or more of these operations, and the like are employed.

The content of the non-functional low molecular siloxane was determined by cutting the cured product of the silicone resin composition into about 2 mm ³ and extracting it in an acetone solvent for 16 hours. The acetone solvent was measured and identified by FID gas chromatography. Value.
In addition, the content of non-functional low molecular siloxane in the component (A) and the component (B) is a value obtained by extracting 1 g of a sample in an acetone solvent for 1 hour, and measuring and identifying this acetone by FID gas chromatography. is there.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated concretely, this invention is not restrict | limited to a following example. In addition, the part in the following example shows a mass part, and a viscosity is a viscosity in 25 degreeC by a rotational viscometer. Me represents a methyl group and Vi represents a vinyl group.

[Example 1]
It is composed of Me ₃ SiO _1/2 , ViMe ₂ SiO _1/2 and SiO _4/2 units, and the total molar ratio of Me ₃ SiO _1/2 and ViMe ₂ SiO _1/2 with respect to SiO _4/2 is 0. 0.8, the vinyl group content relative to the solid content is 0.074 mol / 100 g, and the toluene solution of the silicone resin that is solid at 23 ° C. and the viscosity at 25 ° C. in which both ends are blocked with vinyl groups are 50 mPa · s. The linear dimethylpolysiloxane was mixed at 75 to 25 (mass basis) in terms of solid content. The obtained mixture was treated at 120 ° C. under reduced pressure of 10 mmHg or less to remove toluene, and further, the content of non-functional low molecular siloxane having a vapor pressure of 0.5 mmHg or higher at 150 ° C. by a reduced pressure strip method was 100 ppm. A base compound A reduced to a minimum was obtained.

で示されるエポキシ基含有シロキサン化合物５ｇを混合し、構造中にＳｉＨ基を０．０１３ｍｏｌ／ｇ有する２５℃における粘度が５ｍＰａ・ｓである両末端がトリメチルシリル基で封鎖されたメチルハイドロジェンシロキサン１０ｇを添加し、透明の液状混合物を得た。更に、この混合物１００質量部に対し、ヒュームドシリカを５質量部混合し、ダイボンディング用組成物Ａを得た。 To 100 g of this base compound A, a toluene solution of a platinum catalyst having tetramethylvinyldisiloxane derived from chloroplatinic acid as a ligand was added at 10 ppm (mass basis) in terms of platinum atom, and ethynylcyclohexanol was used as a reaction control agent. 0.1 g, tetramethyltetravinyltetracyclosiloxane 3 g, and the following structural formula (14):

5 g of an epoxy group-containing siloxane compound represented by the formula: 10 g of methylhydrogensiloxane having a SiH group in the structure of 0.013 mol / g and a viscosity at 25 ° C. of 5 mPa · s and having both ends blocked with trimethylsilyl groups. And a clear liquid mixture was obtained. Furthermore, 5 parts by mass of fumed silica was mixed with 100 parts by mass of the mixture to obtain a composition A for die bonding.

  The content of non-functional low molecular siloxane having a vapor pressure of 0.5 mmHg or more at 150 ° C. of the cured product obtained by curing the composition A for die bonding at 150 ° C. for 2 hours was 80 ppm.

(1) Die bonding A silicon wafer having a thickness of 0.3 mm was diced into 1 mm squares to produce dummy chips. An appropriate amount of a die-bonding material (die-bonding composition A obtained above) is applied on a substrate on which a pattern is formed by silver plating on an FR-4 substrate, and a dummy chip is disposed on the die-bonding material. The die bond material was cured by heating at 150 ° C. for 1 hour and then at 150 ° C. for 3 hours. At this time, in order to increase the amount of siloxane to be volatilized and to surely influence the die bonding process, a substrate was placed on a metal flat plate, and 1 g of a die bond material was uniformly applied to an aluminum petri dish having a diameter of 6 cm. Three were prepared, arranged around the substrate, and further covered with a metal can having a diameter of 18 cm and a height of 4 cm, thereby producing a sealed space.
(2) Wire Bonding When wire bonding was attempted on the semiconductor element on which die bonding was performed as described above, there was no defect in wire bonding during 20 trials.

[Comparative Example 1]
It is composed of Me ₃ SiO _1/2 , ViMe ₂ SiO _1/2 and SiO _4/2 units, and the total molar ratio of Me ₃ SiO _1/2 and ViMe ₂ SiO _1/2 with respect to SiO _4/2 is 0. 0.8, the vinyl group content relative to the solid content is 0.074 mol / 100 g, and the toluene solution of the silicone resin that is solid at 23 ° C. and the viscosity at 25 ° C. in which both ends are blocked with vinyl groups are 50 mPa · s. The linear dimethylpolysiloxane was mixed at 75 to 25 (mass basis) in terms of solid content. The resulting mixture was treated at 120 ° C. under a reduced pressure of 10 mmHg or less to remove toluene and obtain base compound B. The content of non-functional low-molecular siloxane having a vapor pressure of 0.5 mmHg or higher at 150 ° C. in this base compound was 2,200 ppm.

The same component as Example 1 was mix | blended with respect to 100 g of this base compound B, and the composition B for die bonding was obtained.
The content of non-functional low molecular siloxane having a vapor pressure of 0.5 mmHg or more at 150 ° C. of the cured product obtained by curing the obtained die bonding composition B under the same conditions as in Example 1 was 2,100 ppm.

  As in Example 1, as a result of performing die bonding and wire bonding, 16 of 20 trials were defective in wire bonding.

Claims (2)

  A die-bonding material for a light-emitting diode, comprising an addition-reaction curable silicone resin composition having a non-functional low-molecular siloxane content of 300 ppm or less having a vapor pressure of 0.5 mmHg or more at 150 ° C. in a cured product. The addition reaction curable silicone resin composition is
(A) Linear organopolysiloxane having at least two alkenyl groups bonded to silicon atoms in one molecule and having a viscosity at 25 ° C. of 1,000 mPa · s or less: 50 to 10 parts by mass (B) Average composition formula (1):
(R ² ₃ SiO _1/2 ) _k (R ¹ R ² ₂ SiO _1/2 ) _m (R ¹ R ² SiO) _n (R ² ₂ SiO) _p
(R ¹ SiO _3/2 ) _q (R ² SiO _3/2 ) _r (SiO _4/2 ) _s (1)
(Wherein R ¹ independently represents an alkenyl group, R ² independently represents an unsubstituted or substituted monovalent hydrocarbon group not containing an aliphatic unsaturated bond, provided that at least 80 mol% of all R ^{2 s)} Is a methyl group, and k, m, n, p, q, r and s are k ≧ 0, m ≧ 0, n ≧ 0, p ≧ 0, q ≧ 0, r ≧ 0 and s ≧ 0, respectively. (However, m + n + q> 0, q + r + s> 0, and k + m + n + p + q + r + s = 1).
A three-dimensional network-like organopolysiloxane resin that is waxy or solid at 23 ° C .: 50 to 90 parts by mass (provided that the total of the component (A) and the component (B) is 100 parts by mass. )
(C) The following average composition formula (2):
R ³ _a H _b SiO _{(4-ab) / 2} (2)
(In the formula, R ³ independently represents an unsubstituted or substituted monovalent hydrocarbon group that does not contain an aliphatic unsaturated bond, provided that at least 50 mol% of all R ³ is a methyl group; (7 ≦ a ≦ 2.1, b is a number satisfying 0.001 ≦ b ≦ 1.0, where a + b is a number satisfying 0.8 ≦ a + b ≦ 3.0.)
And an organohydrogenpolysiloxane having at least two hydrogen atoms bonded to a silicon atom in one molecule: (C) component with respect to all silicon atom-bonded alkenyl groups in component (A) and component (B) 2. The die bond material according to claim 1, comprising an amount of hydrogen atoms bonded to silicon atoms in the amount of 0.5 to 5.0 times mol and (D) a platinum group metal catalyst: an effective amount. .