KR102763788B1 - Addition-curable silicone composition and semiconductor device - Google Patents

Abstract

[Project] To provide an addition-curable silicone composition that provides a cured product having fast curing, high light transmittance, and excellent high-temperature durability, and a semiconductor device using the same.
[Solution] (A) Organopolysiloxane represented by the average unit formula (1) below,
(R ¹ SiO _3/2 ) _a1 (R ¹ ₃ SiO _1/2 ) _b1 (X ¹ O _1/2 ) _c1 … (1)
(B) Organopolysiloxane represented by the average unit formula (2) below,
(R ² ₂ SiO) _a2 (R ² ₃ SiO _1/2 ) _b2 … (2)
(C) Organohydrogenpolysiloxane having at least two Si-H bonds in one molecule, represented by the average composition formula (3) below.
R ³ _d H _e SiO _[(4-de)/2] … (3)
and
(D) Hydrosilylation reaction catalyst
An addition-curing silicone composition characterized by containing .

Description

Addition-curable silicone composition and semiconductor device {ADDITION-CURABLE SILICONE COMPOSITION AND SEMICONDUCTOR DEVICE}

The present invention relates to a semiconductor device having a semiconductor element coated with an addition-curable silicone composition and a cured product of the composition.

Addition-curable silicone compositions that are cured by a hydrosilylation reaction are used as protective coating agents for semiconductor elements in optical semiconductor devices such as photocouplers, light-emitting diodes, and solid-state imaging elements. Such protective coating agents for semiconductor elements sometimes change in hardness or transparency due to heat or light generated from the semiconductor elements. In order to suppress this change, conventional methods have been used by introducing Q units (SiO ₂ ) into the molecule (Patent Documents 1 to 4) or introducing soft segments during the composition (Patent Document 5). However, these methods were unable to respond to permanent changes in the hardness of the material. In addition, since the surrounding elements use resins that are weak to heat and are cured at low temperatures such as 20 to 80°C, the method generally increases the amount of the curing catalyst, which is uneconomical.

Japanese Patent Publication No. 7-252419 Japanese Patent Publication No. 2011-252175 Japanese Patent Publication No. 2013-067683 Japanese Patent Publication No. 2009-052038 Japanese Patent Publication No. 2007-63538

The present invention has been made in consideration of the above circumstances, and has as its object the provision of an addition-curable silicone composition which provides a cured product having rapid curing, high light transmittance, and excellent high-temperature durability, and a semiconductor device using the same.

In order to solve the above problem, in the present invention,

As an additive-curable silicone composition,

(A) Organopolysiloxane represented by the average unit formula (1) below,

(R ¹ SiO _3/2 ) _a1 (R ¹ ₃ SiO _1/2 ) _b1 (X ¹ O _1/2 ) _c1 … (1)

(In the formula, R ¹ is a substituted or unsubstituted aliphatic monovalent hydrocarbon group, which may be the same or different, and 0.1 to 50% of the total R ¹ is an alkenyl group. X ¹ is a hydrogen atom or an alkyl group. a1, b1, and c1 are numbers satisfying 0.1≤a1≤1, 0≤b1≤0.75, 0≤c1≤0.1, and also a1+b1+c1=1.)

(B) Organopolysiloxane represented by the average unit formula (2) below: 0 to 5,000 parts by mass per 100 parts by mass of component (A),

(R ² ₂ SiO) _a2 (R ² ₃ SiO _1/2 ) _b2 … (2)

(In the formula, R ² is a substituted or unsubstituted aliphatic monovalent hydrocarbon group, which may be the same or different, and 0.01 to 25 mol% of the total R ² is an alkenyl group. a2 and b2 are positive numbers satisfying 0.33≤a2≤0.999, 0.001≤b2≤0.67, and a2+b2=1.)

(C) Organohydrogenpolysiloxane having at least two Si-H bonds in one molecule, represented by the average composition formula (3) below: 1 to 200 parts by mass per 100 parts by mass of the total of components (A) and (B),

R ³ _d H _e SiO _[(4-de)/2] … (3)

(In the formula, R ³ is a substituted or unsubstituted monovalent hydrocarbon group, which may be the same or different, excluding an aliphatic unsaturated hydrocarbon group. d and e are positive numbers satisfying 0.7≤d≤2.1, 0.01≤e≤1.0, and also 0.8≤d+e≤2.7.)

and

(D) Hydrosilylation reaction catalyst: an amount of 0.01 to 500 ppm in terms of the mass of metal atoms for the entire composition

The present invention provides an additive-curable silicone composition characterized by containing:

A cured product comprising the additive-curable silicone composition of the present invention is useful as a light-reflecting material, for example, a sealing material for a light-emitting device, particularly a light-emitting diode, because it has fast curing, high light transmittance, and excellent high-temperature durability.

In addition, in the above component (A), it is preferable that R ¹ in the average unit formula (1) contains an alkyl group having 1 to 3 carbon atoms.

In this case, a cured product with better heat resistance and curing properties can be obtained.

In addition, in the above (A) component, it is preferable that among R ¹ in the above average unit formula (1), the content of methyl groups is 80 mol% or more and the remainder is vinyl groups.

In this case, a cured product with better heat resistance and curing properties can be obtained.

In addition, it is preferable to additionally contain 0.01 to 3 parts by mass of either or both of an organosilane compound and an organopolysiloxane containing an epoxy group (E) per 100 parts by mass of the total of component (A) and component (B).

In this way, by including component (E), the adhesiveness can be improved.

In addition, the present invention provides a semiconductor device characterized in that a semiconductor element is coated with a cured product of the above-described additive-curable silicone composition.

Since these semiconductor devices are made of a cured material that is fast curing, has high light transmittance, and has excellent high-temperature durability, they become semiconductor devices with excellent reliability.

A cured product comprising the addition-curable silicone composition of the present invention is useful as a light-reflecting material, for example, a sealing material for a light-emitting device, particularly a light-emitting diode, because it has fast curing, high light transmittance, and excellent high-temperature durability.

FIG. 1 is a schematic cross-sectional view illustrating an example of a semiconductor device of the present invention.

The inventors of the present invention, after careful examination of the above-mentioned problem, discovered that an addition-curable silicone composition containing an organopolysiloxane having a specific structure provides a cured product having excellent curability, transparency, and heat resistance, and completed the present invention.

That is, the present invention,

As an additive-curable silicone composition,

(A) Organopolysiloxane represented by the average unit formula (1) below,

(R ¹ SiO _3/2 ) _a1 (R ¹ ₃ SiO _1/2 ) _b1 (X ¹ O _1/2 ) _c1 … (1)

(In the formula, R ¹ is a substituted or unsubstituted aliphatic monovalent hydrocarbon group, which may be the same or different, and 0.1 to 50% of the total R ¹ is an alkenyl group. X ¹ is a hydrogen atom or an alkyl group. a1, b1, and c1 are numbers satisfying 0.1≤a1≤1, 0≤b1≤0.75, 0≤c1≤0.1, and also a1+b1+c1=1.)

(B) Organopolysiloxane represented by the average unit formula (2) below: 0 to 5,000 parts by mass per 100 parts by mass of component (A),

(R ² ₂ SiO) _a2 (R ² ₃ SiO _1/2 ) _b2 … (2)

(In the formula, R ² is a substituted or unsubstituted aliphatic monovalent hydrocarbon group, which may be the same or different, and 0.01 to 25 mol% of the total R ² is an alkenyl group. a2 and b2 are positive numbers satisfying 0.33≤a2≤0.999, 0.001≤b2≤0.67, and a2+b2=1.)

(C) Organohydrogenpolysiloxane having at least two Si-H bonds in one molecule, represented by the average composition formula (3) below: 1 to 200 parts by mass per 100 parts by mass of the total of components (A) and (B),

R ³ _d H _e SiO _[(4-de)/2] … (3)

(In the formula, R ³ is a substituted or unsubstituted monovalent hydrocarbon group, which may be the same or different, excluding an aliphatic unsaturated hydrocarbon group. d and e are positive numbers satisfying 0.7≤d≤2.1, 0.01≤e≤1.0, and also 0.8≤d+e≤2.7.)

and

(D) Hydrosilylation reaction catalyst: An addition-curable silicone composition containing an amount of 0.01 to 500 ppm in terms of the mass of metal atoms relative to the entire composition.

Hereinafter, the present invention will be described in detail, but the present invention is not limited thereto. In addition, in this specification, viscosity is a value measured by a rotational viscometer.

<Additional curing silicone composition>

The addition-curable silicone composition of the present invention is composed of the following components (A) to (D). Each component is described in detail below.

[(A) Component]

(A) The component is an organopolysiloxane represented by the following average unit formula (1).

(R ¹ SiO _3/2 ) _a1 (R ¹ ₃ SiO _1/2 ) _b1 (X ¹ O _1/2 ) _c1 … (1)

(In the formula, R ¹ is a substituted or unsubstituted aliphatic monovalent hydrocarbon group, which may be the same or different, and 0.1 to 50% of the total R ¹ is an alkenyl group. X ¹ is a hydrogen atom or an alkyl group. a1, b1, and c1 are numbers satisfying 0.1≤a1≤1, 0≤b1≤0.75, 0≤c1≤0.1, and also a1+b1+c1=1.)

Among the alkenyl groups in R ¹ , preferably, a vinyl group, an allyl group, a butenyl group, a pentenyl group, and a hexenyl group are exemplified, and a vinyl group is particularly preferable. Among R ¹ , the content of the alkenyl group is 0.1 to 50 mol%, preferably 0.1 to 30 mol%, and particularly preferably 0.3 to 20 mol%. When it is less than 0.1 mol%, the curability of the composition becomes insufficient, and when it exceeds 50 mol%, the cured product becomes soft.

In addition, examples of the silicon atom-bonded organic group other than the alkenyl group in R ¹ 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; and halogenated alkyl-substituted or unsubstituted aliphatic monovalent hydrocarbon groups such as a chloromethyl group, a 3-chloropropyl group, and a 3,3,3-trifluoropropyl group, and among these, a methyl group is most preferable in terms of heat resistance. It is preferable that the content of the silicon atom-bonded organic group other than these alkenyl groups in R ¹ be 20 mol% or more, and more preferably 40 mol% or more, because stable heat resistance can be imparted.

(A) In the component, if R ¹ in the average unit formula (1) contains an alkyl group having 1 to 3 carbon atoms, this is particularly preferable because a cured product having excellent heat resistance and curability is obtained.

In addition, in the (A) component, if the content of methyl groups among R ¹ in the average unit formula (1) is 80 mol% or more and the remainder is vinyl groups, a cured product having excellent heat resistance and curability is obtained, which is particularly preferable.

X ¹ is a hydrogen atom or an alkyl group, and as the alkyl group, groups similar to those exemplified as R ¹ can be mentioned, and in particular, a methyl group or an ethyl group is preferable.

a1 is 0.1 to 1, b1 is 0 to 0.75, c1 is 0 to 0.1, and a1+b1+c1 is 1. If a1, b1, and c1 are outside the above ranges, the hardness and/or strength of the obtained cured product becomes insufficient.

a1 is preferably 0.15 to 0.9, particularly preferably 0.2 to 0.8, b1 is preferably 0 to 0.5, particularly preferably 0 to 0.4, and c1 is preferably 0 to 0.05.

(A) The molecular weight of the component is not limited, but the weight average molecular weight (Mw) converted to standard polystyrene by gel permeation chromatography (GPC) measurement using a THF solvent is preferably 500 to 20,000, more preferably 700 to 15,000, and particularly preferably 1,000 to 10,000.

[(B) Component]

(B) The component is an organopolysiloxane represented by the following average unit formula (2).

(R ² ₂ SiO) _a2 (R ² ₃ SiO _1/2 ) _b2 … (2)

(In the formula, R ² is a substituted or unsubstituted aliphatic monovalent hydrocarbon group, which may be the same or different, and 0.01 to 25 mol% of the total R ² is an alkenyl group. a2 and b2 are positive numbers satisfying 0.33≤a2≤0.999, 0.001≤b2≤0.67, and a2+b2=1.)

R ² may be the same as R ¹ in component (A), and among R ² , an alkenyl group is preferably exemplified by a vinyl group, an allyl group, a butenyl group, a pentenyl group, and a hexenyl group, and a vinyl group is particularly preferable. Among R ² , the content of the alkenyl group is 0.01 to 25 mol%, preferably 0.1 to 20 mol%, and particularly preferably 0.3 to 20 mol%. When it is less than 0.01 mol%, the curability of the composition becomes insufficient, and when it exceeds 25 mol%, the cured product becomes soft.

In addition, examples of silicon atom-bonded organic groups other than the alkenyl group in R ² 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; and halogenated alkyl substituted or unsubstituted aliphatic monovalent hydrocarbon groups such as a chloromethyl group, a 3-chloropropyl group, and a 3,3,3-trifluoropropyl group, and among these, a methyl group is most preferable in terms of heat resistance. It is preferable that the content of these aliphatic monovalent hydrocarbon groups in R ² be 20 mol% or more, and more preferably 40 mol% or more, because stable heat resistance can be imparted.

a2 is 0.33 to 0.999, preferably 0.90 to 0.998, and more preferably 0.956 to 0.997. b2 is 0.001 to 0.67, preferably 0.002 to 0.10, and more preferably 0.003 to 0.044. When a2 and b2 are out of the above ranges, the hardness and/or strength of the obtained cured product becomes insufficient.

The blending amount of the above component (B) is 0 to 5,000 parts by mass, preferably 10 to 3,000 parts by mass, and more preferably 20 to 1,000 parts by mass, per 100 parts by mass of component (A). If the blending amount exceeds 5,000 parts by mass, sufficient hardness and/or strength cannot be obtained.

[(C) Component]

(C) The component is an organohydrogenpolysiloxane represented by the following average composition formula (3).

R ³ _d H _e SiO _[(4-de)/2] … (3)

(In the formula, R ³ is a substituted or unsubstituted monovalent hydrocarbon group, which may be the same or different, excluding an aliphatic unsaturated hydrocarbon group. d and e are positive numbers satisfying 0.7≤d≤2.1, 0.01≤e≤1.0, and also 0.8≤d+e≤2.7.)

(C) The component has a viscosity at 25°C of preferably 0.5 to 1,000 mPa·s, more preferably 1 to 500 mPa·s.

The monovalent hydrocarbon group represented by R ³ preferably has 1 to 20 carbon atoms, more preferably 1 to 10, and examples of such hydrocarbon groups include saturated hydrocarbon groups such as alkyl groups such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a tert-butyl group, and a hexyl group; cycloalkyl groups such as a cyclohexyl group; aryl groups such as a phenyl group and a tolyl group; aralkyl groups such as a benzyl group and a phenylethyl group; halogen-substituted hydrocarbon groups such as a 3,3,3-trifluoropropyl group; and cyano-substituted hydrocarbon groups, with a methyl group being preferable.

(A) In terms of compatibility with components and physical properties of the cured product, it is preferable that 20 mol% or more of the total R ³ and H (hydrogen atoms) bonded to silicon atoms are methyl groups, and it is more preferable that 50 mol% or more are methyl groups.

(C) The component has at least two, preferably three or more Si-H bonds (i.e., hydrogen atoms bonded to silicon atoms) per molecule, and has a viscosity at 25°C of preferably 0.5 to 1,000 mPa·s, more preferably 1 to 500 mPa·s.

(C) The structure of the siloxane chain of the component is not particularly limited, but is preferably a linear or cyclic organohydrogenpolysiloxane.

d and e are positive numbers satisfying 0.7≤d≤2.1, 0.01≤e≤1.0, and also 0.8≤d+e≤2.7, and if d and e are outside the above ranges, the hardness and/or strength of the obtained cured product becomes insufficient.

d is preferably a positive number satisfying 1.0≤d≤1.8, e is preferably 0.02≤e≤1.0, more preferably 0.10≤e≤1.0, and d+e is preferably 1.01≤d+e≤2.4, more preferably 1.6≤d+e≤2.2.

(C) The blending amount of component is 1 to 200 parts by mass, preferably 5 to 80 parts by mass, per 100 parts by mass of component (A). If the blending amount is less than 1 part by mass, the curability becomes insufficient, and if it exceeds 200 parts by mass, sufficient hardness and/or strength cannot be obtained.

It is more preferable to mix component (C) in an amount such that the molar ratio of silicon atom-bonded hydrogen atoms (i.e., SiH groups) in component (C) to the sum of alkenyl groups in components (A) and (B) is 0.5 to 5 mol/mol, particularly 1 to 3 mol/mol.

[(D) Component]

(D) The hydrosilylation reaction catalyst of component is a catalyst for promoting the hydrosilylation reaction between the alkenyl group of components (A) and (B) and the silicon atom-bonded hydrogen atom of component (C). As this (D) component, a platinum-based catalyst, a rhodium-based catalyst, and a palladium-based catalyst are exemplified, and a platinum-based catalyst is preferable because it can significantly promote the curing of the present composition. As the platinum-based catalyst, a platinum fine powder, chloroplatinic acid, an alcohol solution of chloroplatinic acid, a platinum-alkenylsiloxane complex, a platinum-olefin complex, and a platinum-carbonyl complex are exemplified, and a platinum-alkenylsiloxane complex is particularly preferable. Examples of the alkenylsiloxane include 1,3-divinyl-1,1,3,3-tetramethyldisiloxane, 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane, alkenylsiloxanes in which some of the methyl groups of these alkenylsiloxanes are substituted with groups such as ethyl groups or phenyl groups, and alkenylsiloxanes in which the vinyl groups of these alkenylsiloxanes are substituted with groups such as allyl groups or hexenyl groups. In particular, 1,3-divinyl-1,1,3,3-tetramethyldisiloxane is preferable because the stability of this platinum-alkenylsiloxane complex is good.

In addition, in order to improve the stability of this platinum-alkenylsiloxane complex, it is preferable to add an alkenylsiloxane such as 1,3-divinyl-1,1,3,3-tetramethyldisiloxane, 1,3-diallyl-1,1,3,3-tetramethyldisiloxane, 1,3-divinyl-1,3-dimethyl-1,3-diphenyldisiloxane, 1,3-divinyl-1,1,3,3-tetraphenyldisiloxane, 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane, or an organosiloxane oligomer such as a dimethylsiloxane oligomer, and it is particularly preferable to add an alkenylsiloxane.

(D) The content of the component may be any amount that promotes curing (hydrosilylation reaction) of the composition. Specifically, the content of the metal atom in the component is preferably within the range of 0.01 to 500 ppm by mass unit with respect to the composition, more preferably within the range of 0.05 to 100 ppm, and particularly preferably within the range of 0.01 to 50 ppm. If the content of the component (D) is outside the above range, sufficient curability is not obtained, and problems such as discoloration occur, and furthermore, it is not economical.

[(E) Component]

The addition-curable silicone composition of the present invention may further contain an organosilane compound or organopolysiloxane containing an epoxy group as component (E). Component (E) is an adhesion aid for improving adhesion to silver plating, aluminum, polyphthalamide, alumina ceramics, and polycyclohexylenedimethylene terephthalate, and specific examples of the epoxy group include a glycidoxyalkyl group such as a 3-glycidoxypropyl group or a 4-glycidoxybutyl group; an epoxycyclohexylalkyl group such as a 2-(3,4-epoxycyclohexyl)ethyl group or a 3-(3,4-epoxycyclohexyl)propyl group; an oxiranylalkyl group such as a 4-oxiranylbutyl group or an 8-oxiranyloctyl group, and the like, and an epoxy group-containing monovalent organic group. Organopolysiloxane and organosilane compounds containing these monovalent organic groups are exemplified below.

The content of component (E) is preferably 0.01 to 3 parts by mass, more preferably 0.03 to 2 parts by mass, and even more preferably 0.1 to 1 part by mass, per 100 parts by mass of the total of component (A) and component (B). Within this range, good adhesiveness is obtained without affecting heat resistance.

[Optional ingredients]

The composition may contain, as other optional components, alkyne alcohols such as ethynylcyclohexanol, 2-methyl-3-butyn-2-ol, 3,5-dimethyl-1-hexyn-3-ol, and 2-phenyl-3-butyn-2-ol; enyne compounds such as 3-methyl-3-penten-1-yne and 3,5-dimethyl-3-hexene-1-yne; reaction inhibitors such as 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane, 1,3,5,7-tetramethyl-1,3,5,7-tetrahexenylcyclotetrasiloxane, and benzotriazole. The content of the reaction inhibitor is not limited, but is preferably within the range of 0.0001 to 5 parts by mass with respect to 100 parts by mass of the total of component (A) and component (B).

In addition, the composition may contain an adhesion promoter for improving its adhesiveness. The adhesion promoter is preferably an organosilicon compound having at least 1, and preferably 2 or more, alkoxy groups bonded to silicon atoms per molecule. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, and a methoxyethoxy group, and a methoxy group is particularly preferable. In addition, examples of groups other than the alkoxy group bonded to the silicon atom of the organosilicon compound include substituted or unsubstituted monovalent hydrocarbon groups such as the alkyl group, the alkenyl group, the aryl group, the aralkyl group, and the halogenated alkyl group, which are exemplified as R ¹ , and the like; monovalent organic groups containing an acrylic group such as a 3-methacryloxypropyl group; and hydrogen atoms. Specifically, examples thereof include silane coupling agents such as (meth)acrylic group-containing silane coupling agents and their partial hydrolysis condensation products (oligomers of silane coupling agents).

More specifically, examples thereof include silane compounds such as 3-methacryloxypropyltrimethoxysilane; siloxane compounds having at least one silicon atom-bonded alkenyl group or one silicon atom-bonded hydrogen atom and one silicon atom-bonded alkoxy group per molecule; mixtures of a silane compound or siloxane compound having at least one silicon atom-bonded alkoxy group and a siloxane compound having at least one silicon atom-bonded hydroxy group and one silicon atom-bonded alkenyl group per molecule; methyl polysilicate, ethyl polysilicate, and epoxy group-containing ethyl polysilicate.

It is preferable that this adhesive agent be a low-viscosity liquid, and its viscosity is not limited, but is preferably within the range of 1 to 500 mPa·s at 25°C.

In addition, in the above composition, the content of the adhesive agent is not limited, but is preferably 0.01 to 10 parts by mass with respect to 100 parts by mass of component (A).

In addition, the composition may contain other optional components, such as inorganic fillers such as silica, glass, alumina, and zinc oxide; organic resin fine powder such as polymethacrylate resin; heat-resistant agents, dyes, pigments, flame retardants, and solvents.

In addition, it is preferable that the present composition, upon curing, forms a cured product having a hardness of 10 or more, particularly 30 to 90 in Durometer A as specified in JIS.

In addition, in order to provide sufficient reliability to a semiconductor device having a semiconductor element coated with a cured product of the composition, it is preferable that the cured product obtained by curing has a refractive index (25°C) in visible light (589 nm) of 1.4 or more and a light transmittance (25°C) of the cured product of 80% or more.

In addition, this refractive index can be measured, for example, by an Abbe refractometer. At this time, by changing the wavelength of the light source in the Abbe refractometer, the refractive index at an arbitrary wavelength can be measured. In addition, this light transmittance can be obtained, for example, by measuring a cured product with an optical path length of 2.0 mm by a spectrophotometer.

In addition, it is preferable that the cured product obtained by curing the composition has an ultraviolet ray transmittance (25°C) of 10% or less at a wavelength of 200 nm to 250 nm. This is because, when a semiconductor device formed by covering a semiconductor element with the cured product of the composition is exposed to ultraviolet ray having a short wavelength of 200 nm to 250 nm, deterioration of the material constituting the semiconductor device is prevented. The ultraviolet ray transmittance can be obtained, for example, by measuring a cured product having an optical path length of 2.0 mm using a spectrophotometer.

The composition is cured at room temperature or by heating, but heating is preferable for rapid curing. The heating temperature is preferably in the range of 50 to 200°C.

The cured product obtained by curing the present composition has an elastomer phase, for example, a gel phase, or a flexible rubber phase, and an elastic resin phase. The present composition can be used as an electrical and electronic adhesive, potting agent, protective coating agent, and underfill agent, and is particularly suitable as an adhesive, potting agent, protective coating agent, and underfill agent for semiconductor devices for optical purposes, because of its high light transmittance.

The present invention also provides a semiconductor device using the addition-curable silicone composition of the present invention.

Hereinafter, the semiconductor device of the present invention will be described with reference to the drawings, but the present invention is not limited thereto.

FIG. 1 is a schematic cross-sectional view showing an example of a semiconductor device of the present invention (in this case, an LED (light-emitting diode)).

In the semiconductor device (1) of the present invention, a semiconductor chip (4) is die bonded on a package (3) on which a silver-plated substrate (2) is formed, and the semiconductor chip (4) is wire bonded by a bonding wire (5).

And, the semiconductor chip (4) is coated with the cured product (6) of the additional curable silicone composition of the present invention described above.

The coating of the semiconductor chip (4) is performed by applying the addition-curable silicone composition (6) of the present invention described above and curing the addition-curable silicone composition (6) by heating. In addition, it is of course also possible to cure by a known curing method under other known curing conditions.

In addition, in this case, from the viewpoint of making it difficult to be affected by external stress and suppressing the adhesion of dust, etc. as much as possible, it is preferable that the addition-curing silicone composition (6) forms a cured product having a hardness of 30 or more in Durometer A as specified in JIS by curing.

The addition-curable silicone composition of the present invention forms a cured product having high light transmittance, high adhesion to a substrate, excellent crack resistance, and small change in hardness after heat resistance, and therefore, the semiconductor device of the present invention using the composition of the present invention has excellent reliability and is particularly suitable as a diode, LED, etc.

Example

Hereinafter, examples and comparative examples are shown and the present invention is specifically described, but the present invention is not limited to the following examples, etc.

In addition, the viscosity in the examples is a value at 25°C measured using a rotational viscometer, and the weight average molecular weight is a value converted to standard polystyrene measured by gel permeation chromatography (GPC) using a THF solvent. In addition, the properties of the addition-curable silicone composition and its cured product were evaluated as follows, and the results are shown in Table 1.

[hardenability]

The addition-curable silicone composition was measured at 120°C for 30 minutes using a rheometer MDR2000 manufactured by Alpha Technologies, Inc. The time at which 10% of the torque was reached compared to the end was designated as T10, and the time at which 90% of the torque was reached was designated as T90, to evaluate the speed at which the material reached a cured state. The smaller the difference between T10 and T90, the faster the time at which curing was reached, i.e., the better the curability.

[hardness]

A cured product was produced by heating the additive-curable silicone composition in a hot air circulation oven at 150°C for 3 hours. The hardness of the cured product was measured using a Durometer A durometer.

[Light Transmittance]

The light transmittance at a wavelength of 400 nm at 25°C of a cured product (optical path length: 2.0 mm) produced by curing an additive-curable silicone composition by heating it in a hot air circulation oven at 150°C for 3 hours was measured.

[Crack resistance]

A package manufactured as in Fig. 1 and cured by heating at 150°C for 4 hours was placed in a thermal shock tester with one cycle of {-40°C (30 minutes), 100°C (30 minutes)}, and the package after 100 cycles was observed with an optical microscope. If cracks were observed in the cured product, they were marked as ×, if no cracks were observed, they were marked as ○, and if the presence or absence of cracks was not clear, they were marked as △.

[Heat resistance (transparency)]

The cured product used in the above light transmittance measurement was further heated in a hot air circulation oven at 180°C for 500 hours, and then the light transmittance at a wavelength of 400 nm at 25°C was measured, and the value was converted to 100 for evaluation, with the light transmittance before heating being the value.

[Heat resistance (hardness)]

The cured product used in the above hardness measurement was further heated in a hot air circulation oven at 180℃ for 500 hours, and the hardness of the cured product was measured using a Durometer A hardness tester, and the hardness before heating was converted to a value set as 100 to evaluate the hardness. If the measured value reached or exceeded the measurement limit, it was considered to be above the limit.

[Example 1]

(A) 50 parts by mass of a branched-chain organopolysiloxane represented by the following average unit formula (I) as a component {property = solid phase (25°C), content of silicon atom-bonded vinyl groups out of all silicon atom-bonded organic groups = 4.0 mol%, content of silicon atom-bonded methyl groups out of all silicon atom-bonded organic groups = 96 mol%, weight average molecular weight in standard polystyrene conversion = 13,000}, (B) 50 parts by mass of a dimethylpolysiloxane capped with a molecular chain terminal dimethylvinylsiloxy group (content of silicon atom-bonded vinyl groups = 0.6 mol%), (C) 4.5 parts by mass of an organohydrogenpolysiloxane represented by the following formula (II) (viscosity: 5,000 mPa s), (D) a 1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex of platinum as a component, in an amount of the mass of platinum metal relative to the entire composition. An addition-curable silicone composition having a viscosity of 3,500 mPa·s was prepared by mixing 0.1 mass part of ethynylcyclohexanol as a reaction inhibitor and 0.5 mass part of a compound represented by the following structural formula (III) as an adhesive agent in an amount of 20 ppm in conversion.

(CH ₃ SiO _3/2 ) _0.7 ((CH ₃ ) ₃ SiO _1/2 ) _0.236 ((CH ₂ =CH)(CH ₃ ) ₂ SiO _1/2 ) _0.064 (I)

(CH ₃ ) ₃ SiO((H)(CH ₃ )SiO) ₁₀ Si(CH ₃ ) ₃ (II)

[Example 2]

(A) 50 parts by mass of a branched-chain organopolysiloxane represented by the average unit formula (IV) below as a component {property = solid phase (25°C), content of silicon atom-bonded vinyl groups out of all silicon atom-bonded organic groups = 4.0 mol%, content of silicon atom-bonded methyl groups out of all silicon atom-bonded organic groups = 96 mol%, weight average molecular weight = 15,000}, (B) 50 parts by mass of a dimethylpolysiloxane having a terminal dimethylvinylsiloxy group capped (viscosity 5,000 mPa s, content of silicon atom-bonded vinyl groups = 0.6 mol%) as a component, (C) 5.0 parts by mass of an organohydrogenpolysiloxane represented by the above formula (II) as a component, (D) a 1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex of platinum as a component, in terms of the mass of platinum metal relative to the entire composition, By mixing 0.1 mass part of ethynylcyclohexanol as a reaction inhibitor and 1.0 mass part of a compound represented by the following structural formula (V) as an adhesive agent in an amount of 20 ppm, an addition-curable silicone composition having a viscosity of 3,500 mPa·s was produced.

(CH ₃ SiO _3/2 ) _0.65 ((CH ₃ ) ₃ SiO _1/2 ) _0.286 ((CH ₂ =CH)(CH ₃ ) ₂ SiO _1/2 ) _0.064 (IV)

[Comparative Example 1]

50 parts by mass of a branched-chain organopolysiloxane represented by the average unit formula (VI) below {property = solid phase (25°C), content of silicon atom-bonded vinyl groups out of all silicon atom-bonded organic groups = 7.4 mol%, content of silicon atom-bonded methyl groups out of all silicon atom-bonded organic groups = 92.6 mol%, weight average molecular weight = 3,600}, 50 parts by mass of dimethylpolysiloxane having a terminal dimethylvinylsiloxy group capped (viscosity 5,000 mPa s, content of silicon atom-bonded vinyl groups = 0.6 mol%), 4.0 parts by mass of an organohydrogenpolysiloxane represented by the above formula (II), an amount of a 1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex of platinum that is 20 ppm in mass conversion of platinum metal relative to the entire composition, and ethynylcyclohexanol as a reaction inhibitor. By mixing 0.1 mass part of a silicone adhesive and 2.0 mass parts of a compound represented by the structural formula (V) as an adhesive agent, an addition-curing silicone composition having a viscosity of 6,500 mPa·s was prepared.

(SiO ₂ ) _0.55 [(CH ₂ =CH)(CH ₃ ) ₂ SiO _1/2 ] _0.1 ((CH ₃ ) ₃ SiO _1/2 ) _0.35 (VI)

[Comparative Example 2]

50 parts by mass of a branched-chain organopolysiloxane represented by the average unit formula (VII) below {property = solid phase (25°C), content of silicon atom-bonded vinyl groups out of all silicon atom-bonded organic groups = 6.3 mol%, content of silicon atom-bonded methyl groups out of all silicon atom-bonded organic groups = 93.8 mol%, weight average molecular weight = 5,600}, 50 parts by mass of dimethylpolysiloxane having a terminal dimethylvinylsiloxy group capped (viscosity 5,000 mPa s, content of silicon atom-bonded vinyl groups = 0.6 mol%), 4.0 parts by mass of an organohydrogenpolysiloxane represented by the above formula (II), an amount of a 1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex of platinum that is 20 ppm in mass conversion of platinum metal relative to the entire composition, and ethynylcyclohexanol as a reaction inhibitor. By mixing 0.1 mass part of a silicone adhesive and 2.0 mass parts of a compound represented by the structural formula (V) as an adhesive agent, an addition-curing silicone composition having a viscosity of 6,500 mPa·s was prepared.

(CH ₃ SiO _3/2 ) _0.7 [(CH ₂ =CH)(CH ₃ )SiO] _0.1 ((CH ₃ ) ₃ SiO _1/2 ) _0.2 (VII)

[Comparative Example 3]

45 parts by mass of a branched-chain organopolysiloxane represented by the following average unit formula (VIII) {property = solid phase (25°C), content of silicon atom-bonded vinyl groups out of all silicon atom-bonded organic groups = 20 mol%, content of silicon atom-bonded phenyl groups out of all silicon atom-bonded organic groups = 60 mol%, weight average molecular weight = 1,600}, 55 parts by mass of a methylphenylpolysiloxane having dimethylvinylsiloxy groups capped at both molecular terminals (viscosity 3,500 mPa s, content of silicon atom-bonded vinyl groups = 0.20 mol%, content of silicon atom-bonded phenyl groups out of all silicon atom-bonded organic groups = 49 mol%), 24 parts by mass of a methylphenylpolysiloxane having dimethylhydrogensiloxy groups capped at both molecular terminals represented by the following formula (IX), 1,3-divinyl-1,1,3,3-tetramethyldisiloxane of platinum An addition-curable silicone composition having a viscosity of 1,700 mPa·s was prepared by mixing 0.1 mass part of ethynylcyclohexanol as a reaction inhibitor and 2.0 mass parts of a compound represented by the structural formula (V) as an adhesive agent in an amount of 2.5 ppm based on the mass of platinum metal relative to the entire composition.

(C ₆ H ₅ SiO _3/2 ) _0.75 [(CH ₂ =CH)(CH ₃ ) ₂ SiO _1/2 ] _0.25 (VIII)

H(CH ₃ ) ₂ SiO[CH ₃ (C ₆ H ₅ )SiO] ₄ Si(CH ₃ ) ₂ H (IX)

[Comparative Example 4]

In Example 1, except that the branched-chain organopolysiloxane represented by the above average unit formula (I) was changed to a branched-chain organopolysiloxane represented by the following average unit formula (X) {property = solid (25°C), content of silicon-atom-bonded vinyl groups out of all silicon-atom-bonded organic groups = 16.7 mol%, content of silicon-atom-bonded phenyl groups out of all silicon-atom-bonded organic groups = 3.3 mol%, weight average molecular weight 2,100}, an addition-curable silicone composition having a viscosity of 2,300 mPa·s was produced in the same manner as in Example 1.

(C ₆ H ₅ SiO _3/2 ) _0.05 (CH ₃ SiO _3/2 ) _0.70 [(CH ₂ =CH)(CH ₃ ) ₂ SiO _1/2 ] _0.25 (X)

As shown in Table 1, Examples 1 and 2 had sufficient hardness of the cured product, good curability, light transmittance and heat resistance of the cured product, and no occurrence of cracks in the cured product. In addition, no peeling due to catalyst poison occurred, and the adhesion was high.

Meanwhile, in Comparative Examples 1, 3, and 4, although the hardness was sufficient, cracks were observed, and Comparative Example 1 having SiO ₂ units had poor curing properties. In addition, Comparative Example 2 having SiO units also did not exhibit cracks, but had poor heat resistance. In addition, Comparative Examples 3 and 4 containing organopolysiloxane having phenyl groups also had poor heat resistance. In addition, peeling occurred due to catalyst poison.

In the above respects, it has been demonstrated that the additive-curable silicone composition of the present invention is suitable for various optical applications, etc., because it forms a cured product having high light transmittance, high adhesion to a substrate, and excellent heat resistance and crack resistance.

In the above examples, the addition-curable silicone composition of the present invention was used as a potting agent for semiconductor devices; however, the addition-curable silicone composition of the present invention is also suitable as an adhesive, protective coating agent, underfill agent, etc. for semiconductor devices for optical purposes, particularly because of its high light transmittance, and can also be used as an adhesive, potting agent, protective coating agent, underfill agent, etc. for electrical and electronic purposes.

In addition, the present invention is not limited to the above embodiments. The above embodiments are examples, and anything that has substantially the same configuration as the technical idea described in the claims of the present invention and exhibits the same operational effects is included in the technical scope of the present invention.

1: Semiconductor device
2: Silver plated substrate
3: Package
4: Semiconductor Chip
5: Bonding wire
6: Additive curing silicone composition (cured product)

Claims (5)

As an additive-curable silicone composition,
(A) Organopolysiloxane represented by the average unit formula (1) below,
(R ¹ SiO _3/2 ) _a1 (R ¹ ₃ SiO _1/2 ) _b1 (X ¹ O _1/2 ) _c1 … (1)
(In the formula, R ¹ is a substituted or unsubstituted aliphatic monovalent hydrocarbon group, which may be the same or different, and 0.1 to 50% of the total R ¹ is an alkenyl group. X ¹ is a hydrogen atom or an alkyl group. a1, b1, and c1 are numbers satisfying 0.1≤a1≤1, 0≤b1≤0.75, 0≤c1≤0.1, and also a1+b1+c1=1.)
(B) Organopolysiloxane represented by the average unit formula (2) below: (A) More than 0 mass parts and 5,000 mass parts or less per 100 mass parts of component,
(R ² ₂ SiO) _a2 (R ² ₃ SiO _1/2 ) _b2 … (2)
(In the formula, R ² is a substituted or unsubstituted aliphatic monovalent hydrocarbon group, which may be the same or different, and 0.01 to 25 mol% of the total R ² is an alkenyl group. a2 and b2 are positive numbers satisfying 0.33≤a2≤0.999, 0.001≤b2≤0.67, and a2+b2=1.)
(C) Organohydrogenpolysiloxane having at least two Si-H bonds in one molecule, represented by the average composition formula (3) below: 1 to 200 parts by mass per 100 parts by mass of the total of components (A) and (B),
R ³ _d H _e SiO _[(4-de)/2] … (3)
(In the formula, R ³ is a substituted or unsubstituted monovalent hydrocarbon group, which may be the same or different, excluding an aliphatic unsaturated hydrocarbon group. d and e are positive numbers satisfying 0.7≤d≤2.1, 0.01≤e≤1.0, and also 0.8≤d+e≤2.7.)
and
(D) Hydrosilylation reaction catalyst: an amount of 0.01 to 500 ppm in terms of the mass of metal atoms for the entire composition
An addition-curable silicone composition characterized by containing: An addition-curable silicone composition, characterized in that in the first paragraph, in the component (A), R ¹ in the average unit formula (1) contains an alkyl group having 1 to 3 carbon atoms. An addition-curable silicone composition characterized in that in the first paragraph, in the component (A), among R ¹ in the average unit formula (1), the content of methyl groups is 80 mol% or more and the remainder is vinyl groups. An addition-curable silicone composition characterized in that, in any one of claims 1 to 3, further comprises 0.01 to 3 parts by mass of one or both of an organosilane compound and an organopolysiloxane containing an epoxy group (E) per 100 parts by mass of the total of component (A) and component (B). A semiconductor device characterized in that a semiconductor element is coated with a cured product of the additive-curable silicone composition described in any one of claims 1 to 3.

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