TWI830872B - Silicone resin compositions, hardened materials and optical semiconductor devices for chip bonding - Google Patents

Abstract

The present invention provides a silicone resin composition for wafer bonding that can provide a cured product with low refractive index, high hardness and excellent transparency and wafer shear strength. The silicone resin composition for chip bonding is characterized by containing (A) one molecule having more than two alkenyl groups bonded to Si atoms and one or more CF ₃ (CF ₂ ) _m (CH ₂ ) _n groups, Linear organopolysiloxane with a viscosity of 1,000 mPa·s or less, (B) having more than two alkenyl groups bonded to Si atoms and more than one CF ₃ (CF ₂ ) _o (CH ₂ ) _p group, branched organopolysiloxane having Q unit and/or T unit: 60 to 90 parts by mass relative to 100 parts by mass of the total of components (A) and (B), (C) having Organosilicon compounds with more than 2 SiH groups: 0.5 to 5.0 SiH groups in component (C) per alkenyl group in components (A) and (B), and (D) platinum group metal Department of catalyst.

Description

Silicone resin compositions, hardened materials and optical semiconductor devices for chip bonding

The present invention relates to a silicone resin composition useful in chip bonding of light-emitting diode elements, its cured product, and an optical semiconductor device.

It is proposed to use silicone resin as a chip bonding material for light-emitting diode (hereinafter also referred to as "LED") elements (Patent Documents 1 to 3). Compared with conventional epoxy resins, silicone resin has excellent heat resistance, weather resistance, and discoloration resistance, so it is mainly used in blue LEDs and white LEDs. However, these chip bonding materials made of conventional silicone resin materials are mainly made of methyl-based silicone resin compositions, and the optical element performance is not fully satisfactory, especially the light transmittance of 400 nm is not necessarily high. On the other hand, Patent Document 4 proposes an addition-hardening silicone composition that provides an elastomer with a low refractive index, good transparency, and excellent light-capturing efficiency through a fluorine-containing silicone composition. The composition is used as a sealing material for optical components. However, especially in chip bonding materials, if the resin is too soft, the bonding process may not be possible during the wire bonding step after the chip bonding step. [Prior technical literature] [Patent Document]

[Patent Document 1] Japanese Patent Application Publication No. 2006-342200 [Patent Document 2] Japanese Patent Application Publication No. 2015-093970 [Patent Document 3] Japanese Patent Application Publication No. 2018-150493 [Patent Document 4] Japanese Patent Application Publication No. 2013-010881

[Problem to be solved by the invention]

The present invention was made in view of the above circumstances, and its object is to provide a silicone resin composition for chip bonding that can provide a cured product with low refractive index, high hardness and excellent transparency and wafer shear strength, a cured product thereof, and the same. An optical semiconductor device in which the optical semiconductor element wafer is bonded by a hardened substance. [Means used to solve problems]

In order to achieve the above object, the present invention provides a silicone resin composition for chip bonding, which is characterized by containing: (A) one molecule having more than two alkenyl groups bonded to silicon atoms and one or more alkenyl groups bonded to silicon A linear organopolysiloxane with an atomic CF ₃ -(CF ₂ ) _m -(CH ₂ ) _n -group and a viscosity of 1,000 mPa·s or less at 25°C (however, m is an integer above 0 , n is an integer above 1); (B) One molecule has more than 2 alkenyl groups bonded to silicon atoms and more than 1 CF ₃ -(CF ₂ ) _o -(CH ₂ ) _p -group, and a branched organopolysiloxane having at least one of the siloxane units represented by SiO _4/2 or R ³ SiO _3/2 (however, o is an integer above 0, and p is 1 The above integers, R ³ is a substituted or unsubstituted monovalent hydrocarbon group): relative to the total of 100 parts by mass of the components (A) and (B), the component (B) is 60 to 90 parts by mass; (C) in one molecule An organosilicon compound having two or more hydrogen atoms bonded to a silicon atom: with respect to one alkenyl group bonded to a silicon atom in the component (A) and the component (B), one of the components (C) The number of hydrogen atoms bonded to silicon atoms is 0.5 to 5.0, and (D) a platinum group metal catalyst.

According to the above, the silicone resin composition for wafer bonding of the present invention has a low refractive index and can provide a cured product with high hardness and excellent transparency and wafer shear strength.

In this case, (C) component preferably has one or more CF ₃ -(CF ₂ ) _q -(CH ₂ ) _r -groups bonded to the silicon atom in one molecule (however, q is an integer of 0 or more, and r is an integer above 1).

From the viewpoint of lowering the refractive index, it is also preferred that the component (C) has these groups.

The present invention also provides a silicone cured product, which is a cured product of the silicone resin composition for wafer bonding.

In this way, the cured silicone material of the present invention has a low refractive index, high hardness, and excellent transparency and chip shear strength, and is particularly useful as a chip bonding material for chip bonding of LED elements and the like.

In this case, the refractive index of light with a wavelength of 589 nm at 25° C. is preferably 1.40 or less.

According to this, it can become one with excellent transmittance of visible light at 25° C., especially light with a wavelength of 400 nm, and also one with excellent light capture efficiency.

In addition, the preferred Shore D hardness of the silicone hardened material of the present invention is 40 or more.

In this way, the silicone hardened material according to the present invention is preferable because it has stable connectivity during the wire bonding step after the LED components are bonded in the chip bonding step.

Furthermore, the present invention provides an optical semiconductor device characterized by wafer-bonding optical semiconductor elements using the above-mentioned hardened material.

In this way, the optical semiconductor device according to the present invention has high reliability and improved productivity because defects such as chip peeling and inability to bond are less likely to occur in the wire bonding step performed after the chip bonding step. [Effects of the invention]

The silicone resin composition for chip bonding of the present invention has a low refractive index and can provide a cured product with high hardness and excellent transparency and chip shear strength. It is particularly useful as a chip bonding material for chip bonding of LED components and the like. Furthermore, in the wire bonding step performed after the chip bonding step, defects such as chip peeling and inability to bond are difficult to occur, so the reliability of the optical semiconductor device using the silicone hardened material to bond the optical semiconductor element wafer is high, and its production Sex also improves.

As mentioned above, it is sought to develop a silicone composition that has a low refractive index and can provide a cured material with high hardness, transparency and excellent chip shear strength, and can provide a silicone cured material that can be used as a die bonding material for chip bonding of LED elements and the like. .

As a result of repeated active examination of the above-mentioned problems, the inventors found that the above-mentioned problems can be solved by using a silicone resin composition containing the components (A), (B), (C) and (D) described below, and thus completed the present invention. .

That is, the present invention is a silicone resin composition for wafer bonding, which is characterized by containing (A) one molecule having two or more alkenyl groups bonded to silicon atoms and one or more CF bonded to silicon atoms. _3- (CF ₂ ) _m -(CH ₂ ) _n -based linear organopolysiloxane with a viscosity of 1,000 mPa·s or less at 25°C (however, m is an integer above 0, and n is (an integer above 1), (B) having more than 2 alkenyl groups bonded to silicon atoms and more than 1 CF ₃ -(CF ₂ ) _o -(CH ₂ ) _p - bonded to silicon atoms in one molecule group, and having at least one of the siloxane units represented by SiO _4/2 or R ³ SiO _3/2 (however, o is an integer above 0, and p is an integer above 1 , R ³ is a substituted or unsubstituted monovalent hydrocarbon group): relative to the total of 100 parts by mass of components (A) and (B), component (B) is 60 to 90 parts by mass, and (C) has 2 in one molecule The above organosilicon compound with a hydrogen atom bonded to a silicon atom: with respect to the alkenyl group of one of the aforementioned (A) component and the aforementioned (B) component bonded to a silicon atom, the aforementioned (C) component has an alkenyl group bonded to a silicon atom. The amount of hydrogen atoms in silicon atoms is 0.5 to 5.0, and (D) a platinum group metal catalyst.

The present invention will be described in detail below, but the present invention is not limited thereto.

[Silicon resin composition for chip bonding] The silicone resin composition for chip bonding of the present invention contains components (A) to (D) described below. Each ingredient is explained in detail below.

<(A) Component> (A) Component has two or more alkenyl groups bonded to silicon (Si) atoms and one or more CF ₃ -(CF ₂ ) _m -( CH ₂ ) _n -based linear organopolysiloxane with a viscosity of 1,000 mPa·s or less at 25°C (however, m is an integer greater than or equal to 0, and n is an integer greater than or equal to 1).

The linear organopolysiloxane of component (A) has a viscosity of 1,000mPa·s or less (usually 1 to 1,000mPa·s) at 25°C, preferably 700mPa·s or less (for example, 5 to 700mPa·s) ), preferably within the range of 150mPa·s or less (for example, 10~150mPa·s). When the viscosity exceeds 1,000mPa·s, it is difficult to obtain the target because this component plays a role as a soft segment more than necessary. High hardness. In addition, unless otherwise specified below, the viscosity is the value measured with a rotational viscometer at 25°C.

The alkenyl group bonded to the silicon atom is preferably an alkenyl group having 2 to 10 carbon atoms, especially an alkenyl group having 2 to 6 carbon atoms, such as vinyl, allyl, ethynyl, etc., and vinyl is particularly preferred.

In the CF ₃ -(CF ₂ ) _m -(CH ₂ ) _n -group bonded to the silicon atom (however, m is an integer greater than 0 and n is an integer greater than 1), m preferably satisfies 0≦m≦ As an integer of 9, n is preferably an integer satisfying 1≦n≦10. Based on the synthetic surface, it is preferably represented by CF ₃ -(CH ₂ ) ₂ -, CF ₃ -(CF ₂ ) ₃ -(CH ₂ ) ₂ -, CF ₃ -(CF ₂ ) ₅ -(CH ₂ ) ₂ - the foundation.

The linear organopolysiloxane as component (A) is preferably, for example, an organopolysiloxane represented by the following formula (1). (In the formula, R ¹ can be the same or different and be an alkenyl group, R ² can be the same or different and be a substituted or unsubstituted monovalent hydrocarbon group with 1 to 8 carbon atoms other than an alkenyl group, and Rf ¹ is respectively They may be the same or different, and are the base represented by CF ₃ -(CF ₂ ) _m -(CH ₂ ) _n - (However, m is an integer above 0, and n is an integer above 1), and a is 1~ Integers of 3, x, y, and z are respectively x≧0, y≧1, and z≧0 integers. The siloxane units in brackets with x, y, and z can be arranged in any order).

The alkenyl group represented by R ¹ is preferably an alkenyl group having 2 to 10 carbon atoms, especially an alkenyl group having 2 to 6 carbon atoms, such as vinyl, allyl, or ethynyl, and particularly preferably vinyl.

The substituted or unsubstituted monovalent hydrocarbon group having 1 to 8 carbon atoms other than the alkenyl group represented by R ² is not particularly limited as long as it does not have an alkenyl group. However, it is preferably a substituted or unsubstituted monovalent hydrocarbon group having 1 to 8 carbon atoms. Valent hydrocarbon group. Examples of the monovalent hydrocarbon group include alkyl groups such as methyl, ethyl, propyl and butyl, cycloalkyl groups such as cyclohexyl and cyclopentyl, aryl groups such as phenyl, tolyl and xylyl, and benzyl groups. , aralkyl groups such as phenethyl, etc., halogenated hydrocarbon groups such as chloromethyl, chloropropyl, chlorocyclohexyl, etc. An alkyl group is preferred, and a methyl group is particularly preferred.

Rf ¹ is a base represented by CF ₃ -(CF ₂ ) _m -(CH ₂ ) _n - (where m is an integer greater than or equal to 0, and n is an integer greater than or equal to 1), and m preferably satisfies 0≦m≦9 is an integer, n is preferably an integer satisfying 1≦n≦10. From the viewpoint of ease of synthesis, CF ₃ -(CH ₂ ) ₂ -, CF ₃ -(CF ₂ ) ₃ -(CH ₂ ) ₂ -, and CF ₃ -(CF ₂ ) ₅ -(CH ₂ ) ₂ are preferred. -The basis of representation.

x is an integer above 0, preferably an integer between 0 and 10, and y is an integer above 1, preferably between 2 and 20, and more preferably between 5 and 10. z is an integer above 0, preferably 0 to 10, more preferably 0 to 5. x+y+z is preferably 1~30, more preferably 2~20, and particularly preferably 5~12. And the value of y/(x+y+z) is preferably in the range of 1/20~1/1, more preferably in the range of 1/10~1/1, and particularly preferably in the range of 1/5~1/1.

The linear organopolysiloxane of component (A) can be produced by conventional methods. For example, a cyclic siloxane represented by the following formula (i), a cyclic siloxane represented by the following formula (ii), an organosiloxane represented by the following formula (iii), and if necessary, The cyclic siloxane represented by the formula (iv) is obtained by hydrolysis, copolymerization and condensation in the presence of an alkali or acid catalyst. (In the formula, R ¹ , R ² , Rf ¹ and a are as mentioned above).

Specific examples of component (A) include the following.

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

<(B) Component> (B) Component has two or more alkenyl groups bonded to silicon atoms and one or more CF ₃ -(CF ₂ ) _o -(CH ₂ ) bonded to silicon atoms in one molecule. _p - group, and a branched organopolysiloxane having at least one of the siloxane units represented by SiO _4/2 or R ³ SiO _3/2 (however, o is an integer of 0 or more, and p is 1 or more is an integer, R ³ is a substituted or unsubstituted monovalent hydrocarbon group, which is exemplified by the above-mentioned R ¹ and R ² ). When there are multiple siloxane units having R ³ , R ³ may be the same group or different groups.

Examples of the alkenyl group bonded to the silicon atom are the same as those exemplified in component (A), preferably an alkenyl group having 2 to 10 carbon atoms, more preferably an alkenyl group having 2 to 6 carbon atoms, particularly preferably Vinyl.

Examples of the CF ₃ -(CF ₂ ) _o -(CH ₂ ) _p - group bonded to the silicon atom are the same as those exemplified in component (A). Preferably, CF ₃ -(CH ₂ ) ₂ - is used. , CF ₃ -(CF ₂ ) ₃ -(CH ₂ ) ₂ -, CF ₃ -(CF ₂ ) ₅ -(CH ₂ ) ₂ - represents the base.

The branched organopolysiloxane of component (B) must have a branched structure composed of SiO _4/2 units (Q units) and/or R ³ SiO _3/2 units (T units), but it may further contain methane. R ³ ₂ SiO _2/2 unit (D unit) of vinyl siloxy unit, dimethyl siloxy unit, etc., R of dimethyl vinyl siloxy unit, trimethyl siloxy unit, etc. ³ ₃ SiO _1/2 unit (M unit) (in the formula, R ³ is as mentioned above). The content of SiO _4/2 units and/or R ³ SiO _3/2 units is preferably 5 mol% or more of the total siloxane units in the organopolysiloxane resin of component (B), more preferably 10 ~95 mol%, preferably 20~80 mol%, particularly preferably 20~60 mol%. Moreover, SiO _4/2 units (Q units) in the branched organopolysiloxane of component (B) is relative to the total of SiO _4/2 units (Q units) and R ³ SiO _3/2 units (T units) The amount ratio (Q/(Q+T)) is preferably 0 mol% or more and 40 mol% or less.

(B) The content of alkenyl groups bonded to silicon atoms in component (B) is preferably in the range of 0.01~1 mol per 100g of component (B), more preferably in the range of 0.1~0.6 mol. If the above content is in the range of 0.01~1 mol, the cross-linking reaction will fully proceed and a hardened product with higher hardness can be obtained.

From the viewpoint of easy isolation, the branched organopolysiloxane of component (B) preferably has a weight average molecular weight in the range of 500 to 100,000.

Organopolysiloxanes having these structures can be easily obtained by combining the silane compounds that are the sources of each unit so that the production units are in a desired ratio, and performing (co)hydrolysis in the presence of, for example, an acid.

The compounding amount of component (B) is 60 to 90 parts by mass, preferably 65 to 90 parts by mass, and more preferably 70 to 85 parts by mass relative to 100 parts by mass in total of component (A) and component (B). If the blending amount of the component (B) is less than 60 parts by mass, the hardness of the cured product may be insufficient. If it exceeds 90 parts by mass, the viscosity of the composition may become significantly higher, and the handling when using the composition as a wafer bonding material may become worse. difficulty.

Specific examples of component (B) include the following.

(B) Component may be used individually by 1 type, or may use 2 or more types together.

＜(C)Component＞ Component (C) is an organic silicon compound having two or more hydrogen atoms bonded to silicon atoms (ie, SiH groups) in one molecule. Component (C) functions as a cross-linking agent that undergoes a hydrosilylation reaction with the alkenyl group contained in component (A) and (B) to cross-link.

Component (C) is not particularly limited as long as it is an organosilicon compound having two or more hydrogen atoms bonded to silicon in one molecule. Examples thereof include organohydrogensilanes, organohydrogenpolysiloxanes, etc., but preferred ones are Organohydrogenpolysiloxane. The molecular structure of the organohydrogen polysiloxane is not particularly limited, and for example, linear, cyclic, or branched chain structures can be used.

The organic group bonded to silicon in the component (C) preferably does not have an aliphatic unsaturated group, and can be exemplified by an unsubstituted monovalent hydrocarbon group or a halogen atom (such as a chlorine atom, a bromine atom) or an epoxy group. A monovalent hydrocarbon group substituted by a group (such as epoxy group, glycidyl group, glycidyloxy group), alkoxy group (such as methoxy group, ethoxy group, propoxy group, butoxy group), etc. Examples of these substituted or unsubstituted monovalent hydrocarbon groups are alkyl groups with 1 to 6 carbon atoms, aryl groups with 6 to 10 carbon atoms, more preferably methyl or ethyl groups, or these groups are substituents exemplified above. Substitution base. Furthermore, when the monovalent hydrocarbon group has an epoxy-containing group and/or an alkoxy group as a substituent of the monovalent hydrocarbon group, adhesiveness can be imparted to the cured product of the silicone composition of the present invention.

From the viewpoint of achieving further low refractive index, the organic group bonded to silicon in component (C) is preferably one having CF ₃ -(CF ₂ ) _q -(CH ₂ ) _r -(q is 0 or more Integer, r is an integer above 1). Examples of the CF ₃ -(CF ₂ ) _q -(CH ₂ ) _r - group bonded to silicon include the same ones as those exemplified in component (A) and (B). Preferably, CF ₃ -(CH ₂ ) ₂ -, CF ₃ -(CF ₂ ) ₃ -(CH ₂ ) ₂ -, CF ₃ -(CF ₂ ) ₅ -(CH ₂ ) ₂ - represents the base. Also, among the following, "CF ₃ -(CF ₂ ) _m -(CH ₂ ) _n -group", "CF ₃ -(CF ₂ ) _o -(CH ₂ ) _p -group", "CF ₃ -(CF ₂ ) _q -(CH ₂ ) _r - group” is also collectively referred to as “CF ₃ -(CF ₂ ) _m -(CH ₂ ) _n - group, etc.”

The component (C) has at least 2 hydrogen atoms (SiH groups) bonded to silicon in one molecule, preferably 2 to 200, more preferably 3 to 100, and particularly preferably 4 to 50. When the organosilicon compound of component (C) has a linear or branched chain structure, the SiH groups may be located at only one of the end of the molecular chain and the non-terminal part of the molecular chain, or they may be located at both of them. However, it is preferred that the number of SiH groups located at the non-terminal portion of the molecular chain is greater than the number of SiH groups located at the terminal portion of the molecular chain, and more preferably only located at the non-terminal portion of the molecular chain.

The number of silicon atoms (degree of polymerization) in one molecule of the organosilicon compound of component (C) is preferably 2 to 1,000, more preferably 3 to 200, and still more preferably 4 to 100. Furthermore, it is preferable that the silicon compound of component (C) is liquid at 25°C, and the viscosity at 25°C measured by a rotational viscometer is preferably 1 to 1,000 mPa·s, more preferably 10 to 100 mPa·s.

As the organosilicon compound as the component (C), for example, organohydrogen polysiloxane represented by the following average composition formula (2) can be used. (In the formula, R ⁴ can be the same or different, and is a substituted or unsubstituted monovalent hydrocarbon group without an alkenyl group. a' and b satisfy 0.7≦a'≦2.1, 0.001≦b≦1.0, and 0.8 ≦a'+b ≦3.0, preferably 1.0≦a'≦2.0, 0.01≦b≦1.0, and satisfy 1.5≦a'+b≦2.5).

The substituted or unsubstituted monovalent hydrocarbon group of R ⁴ is not particularly limited as long as it does not have an alkenyl group, but it is preferably a substituted or unsubstituted monovalent hydrocarbon group having 1 to 8 carbon atoms. Examples of the monovalent hydrocarbon group include alkyl groups such as methyl, ethyl, propyl and butyl, cycloalkyl groups such as cyclohexyl and cyclopentyl, and aryl groups such as phenyl, tolyl and xylyl. Aralkyl groups such as benzyl and phenylethyl, chloromethyl, chloropropyl, chlorocyclohexyl, CF ₃ -(CF ₂ ) _q -(CH ₂ ) _r - (however, q is 0 or more, which is higher than Preferably, it is an integer satisfying 0≦q≦9, r is 1 or more, and preferably it is a halogenated alkyl group represented by a group such as an integer satisfying 1≦r≦10).

Among these, R ⁴ is preferably an alkyl group and a halogenated alkyl group, and particularly preferably a methyl group and CF ₃ -(CH ₂ ) ₂ -, CF ₃ -(CF ₂ ) ₃ -(CH ₂ ) ₂ -, CF ₃ -(CF ₂ ) ₅ -(CH ₂ ) ₂ - represents the base.

From the viewpoint of lowering the refractive index, R ⁴ is preferably one having at least one bond to a silicon atom in one molecule, such as CF ₃ -(CF ₂ ) _q -(CH ₂ ) _r - (however, q is An integer above 0, r is an integer above 1).

Examples of the organohydrogen polysiloxane represented by the average composition formula (2) include those represented by the following formula. (In the above formula, R ⁴ is as mentioned above, and c~f are integers above 1).

Among all the organosiloxane units contained in the organohydrogensiloxane represented by the above average composition formula (2), preferably 30 to 70 mol% are methylhydrogensiloxane units.

Furthermore, the organohydrogensiloxane represented by the above average composition formula (2) may also include siloxane units represented by the formula: H ₃ SiO _1/2 , siloxane units represented by the formula: R ⁴ HSiO, and/ Or the siloxane unit represented by the formula: R ⁴ ₂ HSiO _1/2 . The above-mentioned organohydrogensiloxane can also be single organosiloxane unit (M unit), diorganosiloxane unit (D unit), triorganosiloxane unit (T unit) and/or SiO without SiH group _4/2 units (Q units). R ⁴ in the above formula is as described above.

When the component (C) is an organohydrogen polysiloxane having at least 2 SiH groups per molecule, specific examples thereof include 1,1,3,3-tetramethyldisiloxane, 1,3, 5,7-tetramethylcyclotetrasiloxane, tris(hydrogendimethylsiloxy)methylsiloxane, tris(hydrogendimethylsiloxy)phenylsiloxane, methylhydrogencyclopolysiloxane, Methyl hydrogen siloxane·dimethyl siloxane cyclic copolymer, methyl hydrogen polysiloxane with trimethyl siloxy groups at both ends of the molecular chain, trimethyl siloxy groups at both ends of the molecular chain Dimethylsiloxane•methylhydrogensiloxane copolymer, trimethylsiloxy-terminated diphenylsiloxane•methylhydrogensiloxane copolymer at both ends of the molecular chain, Methylphenylsiloxane·methylhydrogensiloxane copolymer terminated with trimethylsiloxy groups, dimethylsiloxane·methylhydrogen terminated with trimethylsiloxy groups at both ends of the molecular chain Siloxane·methylphenylsiloxane copolymer, dimethylsiloxane·methylhydrogensiloxane·diphenylsiloxane copolymer with trimethylsiloxy groups at both ends of the molecular chain, Methyl hydrogen polysiloxane with dimethyl hydrogen siloxy groups at both ends of the molecular chain, dimethyl polysiloxane with dimethyl hydrogen siloxy groups at both ends of the molecular chain, dimethyl polysiloxane with dimethyl hydrogen siloxy groups at both ends of the molecular chain Dimethylsiloxane·Methylhydrogensiloxane copolymer terminated by hydroxysiloxy group, Dimethylsiloxane·Methylphenylsiloxane terminated by dimethylhydrogensiloxy groups at both ends of the molecular chain Oxane copolymer, dimethylsiloxane·diphenylsiloxane copolymer with dimethylhydrogensiloxy end-capped molecular chain, dimethylhydrogensiloxy end-capped dimethylsiloxane copolymer with molecular chain phenylpolysiloxane, diphenylpolysiloxane with dimethylhydrogensiloxy-terminated terminals of the molecular chain, diphenylsiloxane with dimethylhydrogensiloxy-terminated terminals of the molecular chain •Methylhydrogensiloxane copolymer, an organohydrogenpolysiloxane in which part or all of the methyl group in each of the illustrated compounds is substituted by other alkyl groups such as ethyl, propyl, etc., has the formula: R ⁴ ₃ An organosiloxane copolymer composed of siloxane units represented by SiO _1/2 and siloxane units represented by the formula: R ⁴ ₂ HSiO _1/2 and siloxane units represented by the formula: SiO _4/2 , an organosiloxane copolymer composed of siloxane units represented by the formula: R ⁴ ₂ HSiO _1/2 and siloxane units represented by the formula: SiO _4/2 , composed of the formula: R ⁴ HSiO ₂ An organic compound composed of one or both of the siloxane unit represented by _/2 and the siloxane unit represented by the formula: R ⁴ SiO _3/2 and the siloxane unit represented by the formula: H ₃ SiO _1/2 Siloxane copolymers, and mixtures of two or more of these organopolysiloxanes. R ⁴ in the above formula has the same meaning as mentioned above.

Preferable specific examples of component (C) are those represented by the following unit formulas. (In the above formula, the order of the siloxane units in brackets is arbitrary).

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

The compounding amount of component (C) is based on the amount of an alkenyl group bonded to a silicon atom in component (A) and component (B), and the hydrogen atom (SiH) bonded to a silicon atom in component (C). group) becomes 0.5 to 5.0, that is, relative to the total number of alkenyl groups bonded to silicon atoms in components (A) and (B), the hydrogen bonded to silicon atoms in component (C) Atoms (SiH groups) become 0.5 to 5.0 times the amount. From the viewpoint of cross-linking balance, the amount is preferably 0.7 to 3.0 times. If it is less than 0.5 times or exceeds 5.0 times, cross-linking will be insufficient or excessive, and a hardened product with excellent hardness will not be obtained.

＜(D)Component＞ The platinum group metal catalyst of component (D) is a component used to carry out and promote the hydrosilylation reaction of components (A) to (C). The platinum group metal catalyst is not particularly limited, and examples thereof include platinum group metals such as platinum, palladium, and rhodium; chlorinated platinic acid, alcohol-modified chlorinated platinic acid, chlorinated platinic acid and olefins, and vinyl silicon. Platinum compounds such as coordination compounds of oxalane or acetylene compounds, platinum group metal compounds such as tetrakis (triphenylphosphine) palladium, chlorotris (triphenylphosphine) rhodium, etc., but chlorinated platinic acid has been modified with silicon oxygen, It is preferred because it has good compatibility with components (A) ~ (C) and contains almost no chlorine impurities.

(D) Component may be used individually by 1 type, or may use 2 or more types together.

The compounding amount of component (D) only needs to be an effective amount as a catalyst, but it is preferably in the range of 0.1 to 1000 ppm based on the mass of the platinum group metal element relative to the total of components (A) to (C). , preferably in the range of 1~500 ppm.

＜Other ingredients＞ In addition to the above-mentioned (A) to (D), the composition of the present invention may also be formulated with other ingredients illustrated below.

Organic peroxide: In the present invention, by adding organic peroxide, the resin strength can be further improved.

Examples of organic peroxides include 1,6-bis(tert-butylperoxycarbonyloxy)hexane, benzyl peroxide, tert-butylperoxybenzoate, o-methyl Toluyl peroxide, p-toluyl peroxide, dicumyl peroxide, 1,1-bis(tert-butylperoxy)-3,3,3 -Trimethylcyclohexane, bis(4-methylbenzoylperoxy)hexamethylene biscarbonate, etc., but preferably 1,6-bis(tert-butylperoxycarbonyloxy) )hexane. The added amount is an effective amount, but usually 0.01 to 5 parts by mass is prepared based on 100 parts by mass of the total organopolysiloxane of components (A) and (B), and 0.05 to 3 parts by mass is particularly preferred. These may be used individually by 1 type or in combination of 2 or more types.

Reaction inhibitors: The composition of the present invention may use a conventionally known reaction inhibitor (reaction control agent), which is a compound having a hardening inhibitory effect on the addition reaction catalyst of component (D), if necessary. Examples of reaction inhibitors include phosphorus-containing compounds such as triphenylphosphine; nitrogen-containing compounds such as tributylamine, tetramethylethylenediamine, and benzotriazole; sulfur-containing compounds; acetylenic alcohols (for example, 1-ethyne Acetylene compounds such as cyclohexanol, 3,5-dimethyl-1-hexyn-3-ol); hydrogen peroxide compounds; maleic acid derivatives, etc.

The degree of the hardening inhibitory effect using a reaction inhibitor greatly differs depending on the chemical structure of the reaction inhibitor. Therefore, the amount of the reaction inhibitor blended is preferably adjusted to an optimal amount for each reaction inhibitor used. Generally, 0.001 to 5 parts by mass is preferably used based on 100 parts by mass of the total of (A) component, (B) component, (C) component and (D) component.

Adhesion enhancer: In order to improve the adhesion to the resin, an adhesion improving agent may also be added to this composition. As the adhesion enhancer, from the viewpoint of imparting self-adhesiveness to the addition reaction type composition of the present invention, organic silicon compounds such as silane and siloxane containing a functional group for imparting adhesiveness, and non-silicone organic compounds are used. Compounds etc.

Specific examples of the functional group that imparts adhesiveness include alkenyl groups such as vinyl groups and allyl groups bonded to silicon atoms, and hydrogen atoms; and epoxy groups bonded to silicon atoms via carbon atoms (for example, γ- Glycidyloxypropyl, β-(3,4-epoxycyclohexyl)ethyl, etc.), or acryloyloxy (such as γ-acryloxypropyl, etc.) or methacryloxy ( For example, γ-methacryloxypropyl, etc.); alkoxysilyl group (for example, bonded to the silicon atom via an alkylene group that may contain 1 to 2 ester structures, urethane structures, or ether structures) Trimethoxysilyl, triethoxysilyl, methyldimethoxysilyl, alkoxysilyl, etc.), etc.

Examples of the organosilicon compound containing a functional group that imparts adhesion include silane coupling agents, siloxanes having an alkoxysilyl group and an organic functional group, and compounds in which an alkoxysilyl group is introduced into an organic compound having a reactive organic group. Compounds etc.

Examples of the non-silicon organic compound include organic acid allyl ester, epoxy ring-opening catalyst, organic titanium compound, organic zirconium compound, organic aluminum compound, and the like.

Fillers: The composition of the present invention can be filled with inorganic fillers such as crystalline silica, hollow fillers, and sesquioxane, and these fillers can be made of organic alkoxysilane compounds, organochlorosilane compounds, and organic silicon nitrogen. Fillers for surface hydrophobization of organosilicon compounds such as alkane compounds and low molecular weight siloxane compounds; silicone rubber powder, silicone resin powder, etc. As this component, it is particularly preferable to use a filler that can impart thixotropy. By imparting thixotropy, a cured product with excellent workability and wafer shear strength can be obtained.

These other components may be used individually by 1 type, or in combination of 2 or more types.

In addition, in order to achieve good workability of chip bonding (transfer method), the viscosity of the silicone resin composition for chip bonding of the present invention (addition curable silicone resin composition) is preferably 5 to 100 Pa at 25°C.・s, preferably 20~50Pa・s.

[Cured Material] Furthermore, the present invention provides a cured material (silicone cured material) of a silicone resin composition for chip bonding. This silicone hardened material has a low refractive index and high hardness, and is excellent in transparency and chip shear strength. It is particularly useful as a chip bonding material for chip bonding of LED components and the like. In particular, the silicone resin composition for chip bonding of the present invention contains (A) component, (B) component and (C) component as appropriate, and has a CF ₃ (CF ₂ ) _m (CH ₂ ) _n group, etc., so it can A hardened product with low refractive index, improved light transmittance and excellent light capture efficiency is obtained.

In addition, in order to improve the originally desired performance of optical elements such as LEDs, such as the light transmittance at a wavelength of 400 nm at 25°C, the refractive index of the cured material at a wavelength of 589nm at 25°C is preferably 1.40 or less, particularly preferably 1.35 to 1.38. . If so, the transmittance of visible light at 25° C., especially the light with a wavelength of 400 nm, can be achieved more reliably, and the light capture efficiency can also be excellent.

Furthermore, the Shore D hardness of the silicone hardened material of the present invention is preferably 40 or more, more preferably 50 or more, and particularly preferably 55 or more.

If this hardness is achieved, the connectivity in the wire bonding step will also be stable after the LED components are attached in the chip bonding step.

In addition, in order to obtain the silicone resin composition for wafer bonding to obtain the cured product of the present invention, in order to satisfy the characteristics such as refractive index, hardness, etc., the added amounts of the optional components described above can be adjusted.

The silicone resin composition for chip bonding of the present invention can be cured under conventional conditions. For example, it can be cured at 100 to 180° C. for 10 minutes to 5 hours.

The cured product of the silicone resin composition for chip bonding of the present invention has high adhesion to substrates, LED chips, etc., and is particularly useful as a chip bonding material for chip bonding of LED components and the like. As mentioned above, the silicone cured material according to the present invention can be used as an adhesive (chip bonding material) with high adhesion to substrates, LED chips, etc., so it is difficult for the chips to peel off or fail during the wire bonding step. Defects in bonding, etc.

[Optical semiconductor device] Furthermore, the present invention provides an optical semiconductor device in which optical semiconductor elements are chip-bonded using the above-mentioned cured product.

An example of a method for chip bonding optical semiconductor elements using the composition of the present invention is to fill a syringe with the composition of the present invention, and use a glue spreader to apply the composition of the present invention on a base of a package or the like in a dry state to a thickness of 5 to 100 μm. After coating, an optical semiconductor element (such as a light emitting diode) is arranged on the coated composition, and the composition is hardened, thereby wafer-bonding the optical semiconductor element to the substrate. Alternatively, the composition may be placed on a rubber squeegee and stamped while squeegeeing, and the composition may be coated on the substrate to a thickness of 5 to 100 μm in a dry state. A method of wafer-bonding the optical semiconductor element to a substrate by arranging the optical semiconductor element and hardening the composition. The hardening conditions of the composition only need to be as described above. In this way, a highly reliable optical semiconductor device can be produced in which the optical semiconductor element wafer is bonded with the silicone hardened material of the present invention.

The silicone resin composition for chip bonding of the present invention has a low refractive index and can provide a cured product with high hardness and excellent transparency and chip shear strength. Therefore, in the wire bonding step performed after the chip bonding step, it is difficult to cause defects such as chip peeling or failure to bond, and the optical semiconductor device using the silicone hardened material to bond the optical semiconductor element wafer has high reliability and productivity. Also improve. [Example]

The following examples are used to specifically illustrate the present invention, but these examples do not limit the present invention in any way. In addition, the molecular weight is the weight average molecular weight converted to the standard polystyrene of gel permeation chromatography (GPC). The viscosity at 25°C is measured with a rotational viscometer.

In addition, the meaning of the abbreviation of each siloxane unit is as follows.

<Synthesis of component (B)> [Synthesis Example 1] Place 3,3,3-trifluoropropyl-trimethoxysilane 152.6 in a 1L 4-neck flask equipped with a stirring device, a cooling tube, a dropping funnel and a thermometer. g, 35.3g of tetramethoxysilane, 10.5g of hexamethyldisiloxane, 20.9g of 1,3-divinyltetramethyldisiloxane, 32g of isopropyl alcohol and 2.8g of methane sulfonic acid, and stir mix. 34.8 g of water was added dropwise thereto, and 220 g of hexafluoro-m-xylene was added, followed by hydrolysis reaction at 70° C. for 5 hours. 4.6 g of a 50% potassium hydroxide aqueous solution was added thereto, the temperature was raised, low boiling point components were distilled off, and a condensation reaction was performed at 120°C for 5 hours. 1.5 g of methanesulfonic acid was added as a neutralizing agent, and neutralization treatment was performed at 120° C. for 2 hours. After cooling, it was filtered to obtain an organopolysiloxane (B-1) with a weight average molecular weight of 2,200 and an average unit formula of M _1.8 M ^Vi _3.2 Q _4.3 T ^F1 _10.0 .

[Synthesis Example 2] In a 1L 4-neck flask equipped with a stirring device, a cooling tube, a dropping funnel and a thermometer, put (3,3,4,4,5,5,6,6,7,7,8,8 ,8-Tridedecafluorooctyl)trimethoxysilane 280.8g, tetramethoxysilane 47.0g, hexamethyldisiloxane 10.5g, 1,3-divinyltetramethyldisiloxane 20.9g , 32g of isopropyl alcohol and 4.6g of methane sulfonic acid, and stir to mix. 33.6 g of water was added dropwise thereto, and 360 g of hexafluoro-m-xylene was added, followed by hydrolysis reaction at 70° C. for 5 hours. 7.5 g of a 50% potassium hydroxide aqueous solution was added thereto, the temperature was raised, low boiling point components were distilled off, and a condensation reaction was performed at 120°C for 5 hours. 2.4 g of methanesulfonic acid was added as a neutralizing agent, and neutralization treatment was performed at 120° C. for 2 hours. After cooling, it was filtered to obtain an organopolysiloxane (B-2) with a weight average molecular weight of 2,900 and an average unit formula of M _1.3 M ^Vi _2.3 Q _3.9 T ^F3 _5.9 .

[Synthesis Example 3] In a 2L 4-neck flask equipped with a stirring device, a cooling tube, a dropping funnel and a thermometer, 262g of hexafluoro-m-xylene, 489g of water, and 534g of concentrated hydrochloric acid were added, and the temperature was raised to 70°C while stirring. After the temperature rises, 313.7g of 3,3,3-trifluoropropyl-trimethoxysilane, 38.0g of vinylmethyldimethoxysilane, and 3,3,4,4,5,5,6,6 are added dropwise. , 38.7g of 6-nonafluorodichlorosilane and 63.3g of hexafluoro-m-xylene. After the dropwise addition, the mixture was matured at 75°C for 2 hours. After removing the hydrochloric acid water in the upper layer after aging, the organic layer is washed with water, and the process is repeated until the washed water becomes neutral. After washing, 0.1 g of potassium hydroxide was added to the organic layer, and the temperature was raised to 120°C to perform dehydration and condensation reaction. After the reaction is completed, 1 g of potassium acetate and 0.23 g of chlorotrimethylsilane are added to perform a neutralization reaction. After neutralization, filter and concentrate at 100°C/5mmHg for 1 hour to obtain organopolysiloxane (B-3) with a weight average molecular weight of 1,900 and an average unit formula of D ^Vi _2.1 T ^F1 _10.1 D ^F2 _0.7 .

[Example 1] 30 parts by mass of a linear organopolysiloxane with a viscosity of 150 mPa·s expressed as M ^Vi ₂ D ^F1 ₁₀ as the component (A) and the organic material obtained in Synthesis Example 1 as the component (B) 70 parts by mass of polysiloxane (B-1), 24 parts by mass of organohydrogen polysiloxane represented by M ₂ D ^F1 ₁₄ D ^H ₁₄ as component (C), and 0.1 part by mass of 1-ethynylcyclohexanol mix. Furthermore, a 1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex of platinum as component (D) (based on the mass unit of platinum metal relative to the entire composition) is mixed. The amount becomes 15ppm) to obtain the composition. The molar ratio of Si-H group/alkenyl group in the composition is 1.0.

[Example 2] 20 parts by mass of a linear organopolysiloxane with a viscosity of 150 mPa·s expressed as M ^Vi ₂ D ^F1 ₁₀ as the component (A) and the organic material obtained in Synthesis Example 2 as the component (B) 80 parts by mass of polysiloxane (B-2), 15 parts by mass of organohydrogen polysiloxane represented by M ₂ D ^F1 ₁₄ D ^H ₁₄ as component (C), and 0.1 part by mass of 1-ethynylcyclohexanol mix. Furthermore, a 1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex of platinum as component (D) (based on the mass unit of platinum metal relative to the entire composition) is mixed. The amount becomes 15ppm) to obtain the composition. The molar ratio of Si-H group/alkenyl group in the composition is 1.0.

[Example 3] 20 parts by mass of a linear organopolysiloxane with a viscosity of 150 mPa·s expressed as M ^Vi ₂ D ^F1 ₁₀ as the component (A) and the organic material obtained in Synthesis Example 3 as the component (B) 80 parts by mass of polysiloxane (B-3), 20 parts by mass of organohydrogen polysiloxane represented by M ₂ D ^F1 ₁₄ D ^H ₁₄ as component (C), and 0.1 part by mass of 1-ethynylcyclohexanol mix. Furthermore, a 1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex of platinum as component (D) (based on the mass unit of platinum metal relative to the entire composition) is mixed. The amount becomes 15ppm) to obtain the composition. The molar ratio of Si-H group/alkenyl group in the composition is 1.0.

[Comparative Example 1] 25 parts by mass of a linear organopolysiloxane with a viscosity of 60 mPa·s represented by M ^Vi ₂ D ₄₀ , 75 parts by mass of an organopolysiloxane represented by M ^Vi _1.2 M _7.4 Q ₁₀ , 5.3 parts by mass of organohydrogen polysiloxane represented by M ₂ D ^H ₈ and 0.1 part by mass of 1-ethynylcyclohexanol were mixed. Furthermore, a 1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex of platinum (an amount of 15 ppm based on the mass unit of platinum metal relative to the entire composition) was mixed to obtain composition. The molar ratio of Si-H group/alkenyl group in the composition is 1.0.

[Comparative Example 2] 30 parts by mass of organopolysiloxane with a viscosity of 5,000 mPa·s represented by M ^Vi ₂ D ^F1 ₆₀ , 70 parts by mass of organopolysiloxane (B-1) obtained in Synthesis Example 1, and 18 parts by mass of organohydrogen polysiloxane represented by M ₂ D ^F1 ₁₄ D ^H ₁₄ and 0.1 part by mass of 1-ethynylcyclohexanol were mixed. Furthermore, a 1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex of platinum (an amount of 15 ppm based on the mass unit of platinum metal relative to the entire composition) was mixed to obtain composition. The molar ratio of Si-H group/alkenyl group in the composition is 1.0.

[Comparative Example 3] 50 parts by mass of linear organopolysiloxane with a viscosity of 150 mPa·s expressed as M ^Vi ₂ D ^F1 ₁₀ , and 50 parts by mass of organopolysiloxane (B-1) obtained in Synthesis Example 1 , 21 parts by mass of organohydrogen polysiloxane represented by M ₂ D ^F1 ₁₄ D ^H ₁₄ and 0.1 part by mass of 1-ethynylcyclohexanol were mixed. Furthermore, a 1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex of platinum (an amount of 15 ppm based on the mass unit of platinum metal relative to the entire composition) was mixed to obtain composition. The molar ratio of Si-H group/alkenyl group in the composition is 1.0.

Table 1 shows each component used in Examples 1 to 3 and Comparative Examples 1 to 3. SiH group/alkenyl group: The number of SiH in the component (C) relative to one alkenyl group of the component (A) and the component (B) bonded to the silicon atom. Pt complex: 1,3-divene Base-1,1,3,3-tetramethyldisiloxane platinum complex Pt (ppm): Amount of Pt complex relative to the entire composition (mass unit of platinum metal) Reaction control agent: 1-acetylene cyclohexanol

＜Evaluation＞ The following evaluation was performed on the compositions obtained in Examples 1 to 3 and Comparative Examples 1 to 3, and the results are shown in Table 2. [Refractive index] The refractive index of light with a wavelength of 598 nm was measured at 25°C using a refractometer (RX-5000 manufactured by ADAGO Corporation). [Light transmittance] The composition was poured into a mold so as to be 2 mm thick, and the cured product was heated and cured at 150° C. for 3 hours. The light transmittance of straight light with a wavelength of 400 nm was measured at 25° C. using a spectrophotometer. [hardness] The Shore D hardness of the above-mentioned hardened material was measured based on JIS K6253. [Wafer shear strength] Using a wafer bonding machine (AD-830 manufactured by ASM Corporation), the composition is applied to the silver-plated electrode portion of the SMD5050 package (manufactured by I-CHIUN PRECSION INDUSTRY CO., resin component: polyphthalamide) by stamping A quantitative transfer is performed and an optical semiconductor element is mounted thereon. The prepared package was heated in a 150° C. oven for 2 hours to harden the composition, and the lower electrode of the optical semiconductor element was electrically connected to the first lead. Next, use a wire bonding machine to electrically connect the upper electrode of the optical semiconductor element to the second lead using gold wire (FA 25μm, manufactured by Tanaka Electronics Co., Ltd.) on the LED package substrate equipped with the optical semiconductor element, and use a bonding tester ( Dage Co., Ltd., 4000 series) to measure wafer shear strength.

As shown in Table 2, Examples 1 to 3 using the silicone resin composition for chip bonding of the present invention have a refractive index of less than 1.40 and are excellent in light transmittance, hardness and chip shear strength. On the other hand, Comparative Example 1 using a composition that does not have a CF ₃ -(CF ₂ ) _m -(CH ₂ ) _n - group or the like has excellent hardness and wafer shear strength, but the refractive index is higher than 1.40 and light is transmitted through it. Rate difference. Comparative Example 2 using high-viscosity organopolysiloxane and Comparative Example 3 in which the ratio of component (B) to component (A) deviates from the scope of the present invention. The hardness is significantly lower and the chip shear strength is low. As a chip bonding material The reliability is low.

In addition, the present invention is not limited to the above-described embodiment. The above-mentioned embodiments are examples, and any device that has substantially the same configuration as the technical ideas described in the patent application scope of the present invention and can produce the same functions and effects is included in the technical scope of the present invention.

Claims (6)

A silicone resin composition for chip bonding, characterized by containing (A) one molecule having more than two alkenyl groups bonded to silicon atoms and more than one CF ₃ - (CF ₂ ) bonded to silicon atoms. Linear organopolysiloxane with _m -(CH ₂ ) _n - group and a viscosity of 1,000 mPa·s or less at 25°C (however, m is an integer of 0 or more, and n is an integer of 1 or more), (B) One molecule has more than 2 alkenyl groups bonded to silicon atoms and more than 1 CF ₃ -(CF ₂ ) _o -(CH ₂ ) _p -group bonded to silicon atoms, and has SiO Branched organopolysiloxane with at least one siloxane unit represented by _4/2 or R ³ SiO _3/2 (However, o is an integer above 0, p is an integer above 1, and R ³ is a substituted or Unsubstituted monovalent hydrocarbon group): 60 to 90 parts by mass of component (B) relative to 100 parts by mass of components (A) and (B) in total, (C) having more than 2 bonded to silicon atoms in one molecule Organosilicon compound with a hydrogen atom: With respect to an alkenyl group bonded to a silicon atom in the aforementioned component (A) and the aforementioned (B) component, the hydrogen atom bonded to a silicon atom in the aforementioned component (C) becomes The amount is 0.5~5.0 pieces, and (D) a platinum group metal catalyst. For example, the silicone resin composition for chip bonding according to claim 1, wherein the component (C) is a CF ₃ -(CF ₂ ) _q -(CH ₂ ) _r - group having more than one bonded to a silicon atom in one molecule ( However, q is an integer greater than 0, and r is an integer greater than 1). A silicone cured product characterized by being a cured product of the silicone resin composition for chip bonding according to claim 1 or 2. The hardened material of Claim 3, wherein the refractive index of light with a wavelength of 589 nm at 25°C is 1.40 or less. For example, the hardened material of claim 3 or 4 has a Shore D hardness of 40 or above. An optical semiconductor device characterized by wafer-bonding optical semiconductor elements using the hardened material according to any one of claims 3 to 5.