JP2003128920A - Curable liquid silicone composition and semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a curable liquid silicone composition that has good fluidity and impregnating properties by inhibiting the viscosity increase due to the thixotropy, even in the case that a large amount of silica fine particles are used in order to minimize the thermal expansion of the silicone cured products, and to provide semiconductor devices having excellent reliability by coating semiconductor elements with the composition. SOLUTION: The curable liquid silicone composition includes silica fine particles in which the content ratio of isolated silanol groups to the inner silanol groups is >=0.01 in the particles. The semiconductor devices are obtained by coating semiconductor elements with this composition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a curable liquid silicone composition and a semiconductor device. More specifically, even if a large amount of fine silica powder is contained in order to reduce the coefficient of thermal expansion of the cured silicone, the composition exhibits thixotropy. TECHNICAL FIELD The present invention relates to a curable liquid silicone composition having a suppressed increase in viscosity and having good fluidity and impregnation property, and a semiconductor device having excellent reliability obtained by coating a semiconductor element with this composition.

[0002]

2. Description of the Related Art A curable liquid silicone composition containing a large amount of fine silica powder in order to improve the mechanical strength of a silicone cured product or to reduce the coefficient of thermal expansion, for example, having an alkenyl group bonded to a silicon atom. A hydrosilylation reaction-curable liquid silicone composition comprising a liquid organopolysiloxane, a liquid organopolysiloxane having a hydrogen atom bonded to a silicon atom, a metal catalyst for a hydrosilylation reaction, and a fine silica powder has heat resistance and moisture resistance when heated. Uses as a heat-dissipative adhesive, potting agent, protective coating agent for electrical and electronic parts, especially as a semiconductor element protective coating agent and underfill agent because it forms a low stress silicone cured product with excellent properties. Has been done.

In recent years, with the miniaturization and high functionality of semiconductor chips, the pitch of wire wiring intervals has become narrower and the interval between semiconductor chips and substrates has become narrower, but a large amount of fine silica powder is contained. The curable liquid silicone composition has a significantly increased viscosity due to its thixotropy, and its fluidity and impregnability are significantly reduced, resulting in a decrease in the filling property between wire wirings or under the wire wiring, or between the semiconductor chip and the substrate. However, there was a problem that the impregnating property into the resin deteriorated. Then, there is a problem that the reliability of the semiconductor device obtained by coating the semiconductor element with this composition is lowered due to the decrease of the filling property and the impregnating property of this composition.

[0004]

The present inventors have arrived at the present invention as a result of extensive studies on the above problems. That is, the object of the present invention is to contain a large amount of silica fine powder in order to reduce the coefficient of thermal expansion of the silicone cured product,
Provided is a curable liquid silicone composition in which an increase in viscosity due to thixotropy is suppressed and which has good fluidity and impregnability, and a semiconductor device which is obtained by coating a semiconductor element with this composition and has excellent reliability. Especially.

[0005]

The curable liquid silicone composition of the present invention is a curable liquid silicone composition containing a silica fine powder, wherein the isolated silanol is based on the content of internal silanol groups in the silica fine powder. The content ratio of the groups is 0.01 or more. A semiconductor device of the present invention is characterized in that a semiconductor element is coated with the curable liquid silicone composition.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION First, the curable liquid system of the present invention.
The recone composition will be described in detail. The composition has an internal
Content of isolated silanol groups relative to content of lanol groups
Is 0.01 or more, preferably 0.05 or more.
More preferably 0.10 or more, and more preferably
It is preferably 0.15 or more, particularly preferably 0.20 or more.
It is characterized by containing the silica fine powder which is.
This is the isolated silano relative to the content of internal silanol groups.
Silica fine powder having a ratio of the content of diol groups less than the above lower limit
When powder is used, the resulting curable liquid silicone composition
Viscosity increases due to thixotropy, and fluidity and impregnation are remarkable
This is because there is a risk that it will decrease. Also, the internal silano
The ratio of the content of isolated silanol groups to the content of
The upper limit is not particularly limited, but it is preferably 1.0 or less.
Good Here, the internal silanol group means infrared spectroscopic light.
Infrared absorption spectrum measured by a densitometer, 3650 cm
^-1It is a silanol group showing an absorption peak in the vicinity,
On the other hand, an isolated silanol group is an infrared spectrophotometer
In infrared absorption spectrum, 3745 cm^-1Suck near
It is a silanol group showing a collection peak. This internal silano
Ratio of the content of isolated silanol groups to the content of vinyl groups
Depends on the firing conditions and surface treatment during the production of the silica fine powder.
Can be adjusted. In addition, the inclusion of internal silanol groups
Infrared absorption
In the infrared absorption spectrum by a densitometer, internal silano
Base (3650 cm^-1) Isolated peak height
Ranol group (3745 cm^-1) Peak height ratio
Or by the ratio of these peak areas
You can Also, the particle size of this silica fine powder is limited
However, the filling property of the curable liquid silicone composition is not
From the point, the average particle size is within the range of 0.1 to 20 μm.
Preferably.

Examples of such silica fine powder include crystalline silica fine powder and amorphous silica fine powder, and examples of the shape thereof include spherical and irregular shapes. Particularly, amorphous spherical silica fine powder is used. It is preferably a powder. Examples of such silica fine powder include fumed silica fine powder, fused silica fine powder, and silica fine powder in which the dust of metal silicon is deflagrated in an atmosphere containing oxygen, and particularly in an atmosphere containing oxygen. It is preferable that the silica fine powder is made by detonating metallic silicon dust. Further, those obtained by treating the surface of the fine silica powder with an organosilicon compound such as organohalosilane, organoalkoxysilane, or organosilazane, or other organic compound may be used.

The content of the fine silica powder in the composition is not limited, but is preferably in the range of 10 to 500 parts by weight with respect to 100 parts by weight of the organopolysiloxane which is the main component of the composition. , Especially 20-5
It is preferably within the range of 00 parts by weight. This is because if the content of the silica fine powder is less than the lower limit of the above range, the mechanical strength of the obtained silicone cured product may be lowered, or the coefficient of thermal expansion may increase, while the above range is exceeded. If the upper limit of is exceeded, the fluidity of the resulting curable silicone composition will be poor.

The curing mechanism of the present composition is not limited, and examples thereof include a hydrosilylation reaction, a condensation reaction, and a radical reaction with an organic peroxide, and a hydrosilylation reaction is particularly preferable. This hydrosilylation-curable liquid silicone composition includes (A) 100 parts by weight of a liquid organopolysiloxane having at least two alkenyl groups bonded to silicon atoms in one molecule, and (B) hydrogen atoms bonded to silicon atoms. Liquid organopolysiloxane having at least two in one molecule 0.001 to 100 parts by weight, (C) metal catalyst for hydrosilylation reaction (the metal atom in the catalyst is 0 in weight unit relative to the composition) 0.01 to 1,000 ppm), (D) Silica fine powder in which the ratio of the content of the isolated silanol groups to the content of the internal silanol groups is 0.01 or more Curable property of at least 10 to 500 parts by weight A liquid silicone composition is exemplified.

The liquid organopolysiloxane as the component (A) is the main component of the above composition and is characterized by having at least two alkenyl groups bonded to silicon atoms in one molecule. Examples of the molecular structure of the component (A) include linear, linear with some branches, branched, cyclic, and net-like. Further, the bonding position of the alkenyl group bonded to the silicon atom in the component (A) is exemplified by the molecular chain terminal and / or the molecular chain side chain. Examples of the group bonded to a silicon atom other than the alkenyl group in the component (A) include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group,
Alkyl group such as heptyl group; aryl group such as phenyl group, tolyl group, xylyl group, naphthyl group; aralkyl group such as benzyl group, phenethyl group; chloromethyl group, 3-chloropropyl group, 3,3,3-tri Substituted or unsubstituted monovalent hydrocarbon groups such as halogenated alkyl groups such as fluoropropyl groups are exemplified, and methyl group and phenyl group are particularly preferable. The component (A) is liquid at 25 ° C., and its viscosity is not limited, but it is 10 to 1,000,0.
It is preferably in the range of 00 mPa · s, and particularly 1
It is preferably in the range of 00 to 50,000 mPa · s. This is because if the viscosity at 25 ° C. is less than the lower limit of the above range, the physical properties of the resulting silicone cured product may deteriorate, while if it exceeds the upper limit of the above range, the curable silicone obtained. This is because the fluidity of the composition may decrease.

The liquid organopolysiloxane as the component (B) is a curing agent for the above composition and is characterized by having at least two hydrogen atoms bonded to silicon atoms in one molecule. Examples of the molecular structure of this component (B) include linear, partially branched linear, branched, and network structures. Examples of the bonding position of the hydrogen atom include the molecular chain end and / or the molecular chain side chain. Further, as the group bonded to a silicon atom other than the hydrogen atom in the component (B), a methyl group,
Alkyl groups such as ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group; aryl groups such as phenyl group, tolyl group, xylyl group, naphthyl group; aralkyl groups such as benzyl group, phenethyl group; chloromethyl Base,
Substituted or unsubstituted monovalent hydrocarbon groups such as halogenated alkyl groups such as 3-chloropropyl group, 3,3,3-trifluoropropyl group and the like are exemplified, and particularly preferably methyl group and phenyl group. . The component (B) is liquid at 25 ° C., and its viscosity is not limited, but it is 0.1 to 1.0.
It is preferably in the range of 000,000 mPa · s, and particularly preferably in the range of 1 to 50,000 mPa · s. This is because if the viscosity at 25 ° C. is less than the lower limit of the above range, the composition is hard to volatilize and the composition of the resulting curable silicone composition is difficult to stabilize. This is because the fluidity of the silicone composition may decrease.

The content of the component (B) is in the range of 0.001 to 100 parts by weight based on 100 parts by weight of the component (A). This is because when the content of the component (B) is less than the lower limit of the above range, the obtained silicone composition may not be sufficiently cured, while when it exceeds the upper limit of the above range, it is obtained. This is because the physical properties of the cured silicone may deteriorate.

The metal-based catalyst for hydrosilylation reaction of the component (C) is a catalyst for promoting the hydrosilylation reaction of the above composition, and examples thereof include platinum-based catalysts, rhodium-based catalysts and palladium-based catalysts. It is preferably a platinum-based catalyst. Examples of the platinum-based catalyst include platinum-based powder such as platinum fine powder, platinum black, platinum-supported silica fine powder, platinum-supported activated carbon, chloroplatinic acid, alcohol solution of chloroplatinic acid, olefin complex of platinum, alkenylsiloxane complex of platinum, and the like. Is exemplified.

The content of the component (C) is such that the metal atom in the catalyst is 0.01 to 1.0 by weight unit with respect to the above composition.
The amount is within the range of 00 ppm. This is because if the content of the component (C) is less than the lower limit of the above range, the hydrosilylation reaction of the obtained silicone composition may not proceed sufficiently, while the content of the component (C) exceeds the upper limit of the above range. However, this is because the hydrosilylation reaction is not significantly promoted, and rather the silicone cured product may cause problems such as coloring.

The silica fine powder as the component (D) is a component characterizing the above composition, and the ratio of the content of the isolated silanol groups to the content of the internal silanol groups is 0.01 or more, preferably 0.00. It is characterized by being 05 or more, more preferably 0.10 or more, further preferably 0.15 or more, and particularly preferably 0.20 or more. This is, when the ratio of the content of the isolated silanol group to the content of the internal silanol group is less than the above lower limit, the viscosity increases due to the thixotropy of the resulting curable liquid silicone composition, and the fluidity and impregnability are This is because there is a risk of a significant decrease. The upper limit of the ratio of the content of isolated silanol groups to the content of internal silanol groups is not particularly limited, but is preferably 1.0 or less. here,
The internal silanol group is a silanol group showing an absorption peak near 3650 cm ⁻¹ in an infrared absorption spectrum by an infrared spectrophotometer, while the isolated silanol group is an infrared absorption spectrum by an infrared spectrophotometer, It is a silanol group showing an absorption peak near 3745 cm ^-1 . The ratio of the content of the isolated silanol groups to the content of the internal silanol groups can be adjusted by the firing conditions during the production of the component (D), the surface treatment and the like. In addition, the ratio of the content of the internal silanol group and the content of the isolated silanol group is determined by the internal silanol group (3650c
isolated silanol groups to the height of the peak of the m ^-1) (37
It can be determined by the ratio of the heights of the peaks of 45 cm ⁻¹ ) or the ratio of the areas of these peaks.
Although the particle size of the component (D) is not limited, the average particle size thereof is preferably in the range of 0.1 to 20 μm from the viewpoint of filling properties into the curable liquid silicone composition. Examples of the fine silica powder as the component (D) include the same fine powders as described above.

The content of the component (D) is in the range of 10 to 500 parts by weight, preferably in the range of 20 to 500 parts by weight, based on 100 parts by weight of the component (A). This is (D)
When the content of the component is less than the lower limit of the above range, the mechanical strength of the obtained silicone cured product may be lowered, or the coefficient of thermal expansion may increase, while when the upper limit of the above range is exceeded. This is because the resulting curable silicone composition has poor fluidity.

The above-mentioned composition comprises at least components (A) to (D), but as an optional component, 3-methyl-1-
Alkyne alcohols such as butyn-3-ol, 3,5-dimethyl-1-hexyne-3-ol, phenylbutynol; 3-methyl-3-penten-1-yne, 3,5-
Enyne compounds such as dimethyl-3-hexene-1-yne; 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane, 1,3,5,7-tetramethyl- A reaction inhibitor such as 1,3,5,7-tetrahexenylcyclotetrasiloxane or benzotriazole may be contained. In the above composition, the content of the reaction inhibitor is not limited, but it is preferably in the range of 0.0001 to 5 parts by weight with respect to 100 parts by weight of the component (A).

Further, the composition may contain an adhesiveness-imparting agent for improving its adhesiveness. The adhesiveness imparting agent is preferably an organosilicon compound having at least one alkoxy group bonded to a silicon atom in one molecule. As this alkoxy group,
Methoxy group, ethoxy group, propoxy group, butoxy group,
A methoxyethoxy group is exemplified, and a methoxy group is particularly preferable. Further, as the groups other than the alkoxy group bonded to the silicon atom of the organosilicon compound, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group,
Alkyl group such as hexyl group, heptyl group; alkenyl group such as vinyl group, allyl group, butenyl group, pentenyl group, hexenyl group; aryl group such as phenyl group, tolyl group, xylyl group, naphthyl group; benzyl group, phenethyl group An aralkyl group such as; a substituted or unsubstituted monovalent hydrocarbon group such as a halogenated alkyl group such as a chloromethyl group, a 3-chloropropyl group, a 3,3,3-trifluoropropyl group;
Glycidoxyalkyl groups such as 3-glycidoxypropyl group and 4-glycidoxybutyl group; 2- (3,4-epoxycyclohexyl) ethyl group, 3- (3,4-epoxycyclohexyl) propyl group and the like Epoxycyclohexylalkyl group; epoxy group-containing monovalent organic group such as oxiranylalkyl group such as 4-oxiranylbutyl group and 8-oxiranyloctyl group; acryl group-containing monovalent group such as 3-methacryloxypropyl group Organic group; a hydrogen atom is exemplified. Since it can give good adhesion to various base materials,
This organosilicon compound preferably has at least one epoxy group-containing monovalent organic group in one molecule. Examples of such organosilicon compounds include silane compounds and siloxane compounds. Examples of the molecular structure of the siloxane compound include linear, partially branched linear, branched, cyclic, and network structures, and particularly preferably linear, branched, and network structures. . Examples of such organosilicon compounds include silane compounds such as 3-glycidoxypropyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and 3-methacryloxypropyltrimethoxysilane; A siloxane compound having at least one silicon atom-bonded alkenyl group or silicon atom-bonded hydrogen atom and at least one silicon atom-bonded alkoxy group, a silane compound having at least one silicon atom-bonded alkoxy group, or a siloxane compound and silicon in one molecule. A mixture of a siloxane compound having at least one atom-bonded hydroxy group and at least one silicon-bonded alkenyl group, the formula:

[Chemical 1] (In the formula, a, b, and c are positive numbers), a siloxane compound represented by the formula:

[Chemical 2] (In the formula, a, b, c, and d are positive numbers.) Are exemplified by the siloxane compound. This adhesion-imparting agent is preferably a low-viscosity liquid, and its viscosity is not limited, but it is preferably in the range of 1 to 500 mPa · s at 25 ° C. In the above composition, the content of the adhesion-imparting agent is not limited, but it is preferably in the range of 0.01 to 10 parts by weight with respect to 100 parts by weight of the component (A).

In the above composition, as other optional components, a thermally conductive filler such as silica fine powder other than the silica fine powder of the present invention, alumina powder, aluminum nitride powder, boron nitride powder; silver powder, copper Conductive filler such as powder; Organic resin fine powder such as silicone resin and fluororesin; Others
It may contain a dye, a pigment, a flame retardant, a solvent and the like.

The above-mentioned composition can be prepared by mixing the components (A) to (D), and any other components. The component (D) may be previously prepared in whole or part of the component (A). After mixing with, it is preferable to mix with other ingredients.

The above composition can undergo a hydrosilylation reaction at room temperature or by heating to form a cured silicone product. Since this hydrosilylation reaction can be carried out rapidly, heating to 50 to 250 ° C. is preferable, and heating to 80 to 200 ° C. is particularly preferable. Examples of the silicone cured product thus obtained include resin, rubber and gel, and rubber and gel are particularly preferable.

The curable liquid silicone composition of the present invention comprises
Even if a large amount of silica fine powder is contained in order to reduce the thermal expansion coefficient of the silicone cured product, the increase in viscosity due to thixotropy is suppressed, the viscosity is relatively low, and since it has good fluidity and impregnability, It can be used as an electric / electronic adhesive, potting agent, protective coating agent, and underfill agent, and is particularly suitable as a protective coating agent for semiconductor elements and an underfill agent between a semiconductor element and a substrate.

Next, the semiconductor device of the present invention will be described in detail. The semiconductor device of the present invention is characterized in that a semiconductor element is coated with the curable liquid silicone composition. As this semiconductor element, a diode,
Examples include semiconductor elements in transistors, thyristors, monolithic ICs, and hybrid ICs. Such semiconductor devices include diodes, transistors, thyristors, monolithic ICs, hybrid I
Examples are C, LSI, and VLSI.

LSI which is an example of the semiconductor device of the present invention
(Cross-sectional view) is shown in FIGS. 1 and 2. In the semiconductor device of FIG. 1, a semiconductor element 1 is mounted on a circuit board 2,
Circuit wiring 3 connected to the semiconductor element 1 and the external leads 5.
And are electrically connected by a conductive wire 4.
The semiconductor element 1 is covered with a cured product 6 of a curable liquid silicone composition filled in a resin frame material 7. Examples of the material of the circuit board 2 include organic resins such as polyimide resin, bismaleimide triazine resin, glass fiber reinforced epoxy resin, bakelite resin, and phenol resin; ceramics such as alumina; metals such as copper and aluminum. Further, examples of the material of the circuit wiring 3 include gold, copper, and silver-palladium. Examples of the material of the conductive wire 4 include gold, gold alloy, aluminum and copper. The semiconductor element 1 is mounted on the circuit board 2.
Besides, electronic components such as resistors, capacitors, and coils may be mounted.

As a method of manufacturing this semiconductor device,
The semiconductor element 1 is mounted on the circuit board 2, then the semiconductor element 1 and the circuit wiring 3 are electrically connected by the conductive wire 4, and then the frame member 7 is placed around the semiconductor element 1. The curable liquid silicone composition is filled in this. An example of a method of curing the curable liquid silicone composition is a method of heating at 50 to 200 ° C.

On the other hand, in the semiconductor device shown in FIG. 2, the semiconductor element 1 is mounted on the circuit board 2 having the circuit wiring 3 formed by printing on the surface and the external leads 5 at the ends, and the semiconductor element is mounted. 1 and the circuit wiring 3 are electrically connected by a conductive bump 8. Examples of the material of the conductive bump 8 include gold, gold alloy, aluminum, silver, silver alloy, and nickel. In addition, this semiconductor device 1
A cured product of the curable liquid silicone composition used as an underfill agent is filled between the and the circuit board 2.

As a method of manufacturing this semiconductor device,
The semiconductor element 1 is mounted on the circuit board 2, and then the semiconductor element 1 and the circuit wiring 3 are electrically connected by the conductive bumps 8. Then, the semiconductor element 1 and the circuit board 2 are hardened between the semiconductor element 1 and the circuit board 2. The liquid silicone composition is impregnated and cured.
An example of a method of curing the curable liquid silicone composition is a method of heating at 50 to 200 ° C.

[0028]

EXAMPLES The curable liquid silicone composition and semiconductor device of the present invention will be described in detail with reference to Examples. The viscosity is a value at 25 ° C. Further, the ratio of the content of isolated silanol groups to the content of internal silanol groups of the silica fine powder, the viscosity of the curable liquid silicone composition, the thixotropy, and the thermal expansion coefficient of the silicone cured product were measured as follows. . Further, the reliability of the semiconductor device was evaluated as follows.

[Ratio of content of isolated silanol group to content of internal silanol group of fine silica powder] Infrared absorption of internal silanol group (3650 cm ^-1 ) and isolated silanol group (3745 cm ^-1 ) by infrared absorption spectrophotometer The peak height of each absorption peak (infrared absorption intensity from the baseline to the top of the peak) is determined by measuring the infrared absorption of, and the peak height of the isolated silanol group relative to the peak height of the internal silanol group is calculated. The ratio (the ratio of infrared absorption intensity) was calculated.

[Viscosity of curable liquid silicone composition, thixotropy] The viscosity of the curable liquid silicone composition was measured with a rotary viscometer using a spindle, and the rotation speed was 30 rp.
It is shown by the value measured in m. Also, the viscosity at a rotation speed of 6 rpm was similarly measured, and the value of the viscosity at a rotation speed of 6 rpm with respect to the viscosity at a rotation speed of 30 rpm was determined as an index showing the thixotropy of the curable liquid silicone composition. The larger this value, the greater the thixotropy.

[Coefficient of thermal expansion of cured silicone] Using a coefficient of thermal expansion for solid samples, the cured silicone of 25 ° C to
The coefficient of thermal expansion at 200 ° C. was measured.

[Reliability of Semiconductor Device (Part 1)] The semiconductor device shown in FIG. 1 was manufactured as follows. After mounting the semiconductor element 1 on the circuit board 3 made of glass fiber reinforced epoxy resin having the circuit wiring 3 formed by printing on the surface and the external leads 5 at the ends, the semiconductor element 1 and the circuit wiring 3 are made of gold. It was electrically connected by a wire 4 made of. Next, the semiconductor element 1 was surrounded by a resin frame material 7, a curable liquid silicone composition was filled therein with a dispenser, and then heated in a hot air circulation oven at 150 ° C. to be cured. The 20 semiconductor devices thus prepared were subjected to a thermal cycle test of 500 cycles of −65 ° C. for 30 minutes and + 150 ° C. for 30 minutes as one cycle, and then a continuity test between the external leads 5 was performed.
The conduction failure rate was calculated.

[Reliability of Semiconductor Device (Part 2)] The semiconductor device shown in FIG. 2 was prepared as follows. After mounting the semiconductor element 1 on the circuit board 3 made of glass fiber reinforced epoxy resin having the circuit wiring 3 formed by printing on the surface and the external leads 5 at the ends, the semiconductor element 1 and the circuit wiring 3 are made of gold. Electrical connection was made with bumps 8 made of. A curable liquid silicone composition was impregnated between the semiconductor element 1 and the circuit board 2 from one end of the semiconductor element 1 by a dispenser, and then heated in a hot air circulation oven at 150 ° C. to be cured. Twenty semiconductor devices thus prepared were subjected to 96 atmosphere in an atmosphere of 121 ° C. and 100% RH.
After conducting a high-temperature and high-humidity test in which the external lead 5
A continuity test was conducted between them to determine the continuity failure rate.

[Example 1] 65% by weight of dimethylpolysiloxane blocked with dimethylvinylsiloxy groups at both ends of the molecular chain
(CH ₂ ═CH) (CH ₃ ) ₂ SiO _1/2 unit and (CH ₃ ) ₃ SiO
A mixture of _1/2 unit and 35% by weight of an organopolysiloxane resin composed of ₂ units of SiO ₄ (viscosity = 600
0 mPa · s; content of vinyl group bonded to silicon atom = 0.
80 wt%) 60 parts by weight of spherical silica fine powder prepared by detonating metallic silicon dust in an atmosphere containing oxygen (ratio of the content of isolated silanol groups to the content of internal silanol groups = 0.26; average (Particle size = 1.5 μm) 35 parts by weight were uniformly mixed to prepare a base.

Next, a viscosity of 20 mPa.s is added to the total amount of this base.
Methyl hydrogen polysiloxane with trimethylsiloxy groups blocked at both ends of the molecular chain (content of hydrogen atoms bonded to silicon atoms = 0.75% by weight) 3.0 parts by weight, platinum 1,
3-divinyltetramethyldisiloxane complex (in the composition, the amount of platinum metal in the complex is 5 ppm by weight), 3-phenyl-1-butyn-3-ol.
Formula of 01 parts by weight and viscosity of 20 mPa · s:

[Chemical 3] The liquid silicone rubber composition was prepared by uniformly mixing 1.0 part by weight of the adhesion-imparting agent represented by Table 1 shows the viscosity of this composition, the value showing thixotropy, and the coefficient of thermal expansion of the silicone rubber. In addition, Table 1 shows the results of the reliability of the semiconductor device manufactured using this composition.

Comparative Example 1 In Example 1, spherical silica fine powder obtained by detonating metallic silicon dust in an atmosphere containing oxygen instead of spherical silica fine powder (based on the content of internal silanol groups) A liquid silicone rubber composition was prepared in the same manner as in Example 1 except that the ratio of the content of isolated silanol groups = 0.005; the average particle size = 1.5 μm) was used. Table 1 shows the viscosity of this composition, the value showing thixotropy, and the coefficient of thermal expansion of the silicone rubber. In addition, Table 1 shows the results of the reliability of the semiconductor device manufactured using this composition.

[Comparative Example 2] In Comparative Example 1, the content of the spherical silica fine powder was 27 parts by weight, and dimethylpolysiloxane 65 capped with dimethylvinylsiloxy groups at both molecular chain ends was used.
% By weight and (CH ₂ = CH) (CH ₃ ) ₂ SiO _1/2 units and (CH ₃ ).
_A liquid silicone rubber composition was prepared in the same manner as in Comparative Example 1 except that the content of the mixture of 35% by weight of an organopolysiloxane resin composed of ₃ SiO _1/2 units and SiO _4/2 units was 68 parts by weight. Prepared. Table 1 shows the viscosity of this composition, the value showing thixotropy, and the coefficient of thermal expansion of the silicone rubber. In addition, Table 1 shows the results of the reliability of the semiconductor device manufactured using this composition.

[Example 2] 65% by weight of dimethylpolysiloxane blocked with dimethylvinylsiloxy groups at both ends of the molecular chain
(CH ₂ ═CH) (CH ₃ ) ₂ SiO _1/2 unit and (CH ₃ ) ₃ SiO
A mixture of _1/2 unit and 35% by weight of an organopolysiloxane resin composed of ₂ units of SiO ₄ (viscosity = 600
0 mPa · s; content of vinyl group bonded to silicon atom = 0.
80 wt%) 60 parts by weight of spherical silica fine powder prepared by sol-gel method and then calcined (ratio of content of isolated silanol groups to content of internal silanol groups = 0.45; average particle size) A base was prepared by uniformly mixing 35 parts by weight (diameter = 2.0 μm).

Next, a viscosity of 20 mPa · s was added to the total amount of this base.
Methyl hydrogen polysiloxane with trimethylsiloxy groups blocked at both ends of the molecular chain (content of hydrogen atoms bonded to silicon atoms = 0.75% by weight) 3.0 parts by weight, platinum 1,
3-divinyltetramethyldisiloxane complex (in the composition, the amount of platinum metal in the complex is 5 ppm by weight), 3-phenyl-1-butyn-3-ol.
Formula of 01 parts by weight and viscosity of 20 mPa · s:

[Chemical 4] The liquid silicone rubber composition was prepared by uniformly mixing 1.0 part by weight of the adhesion-imparting agent represented by Table 1 shows the viscosity of this composition, the value showing thixotropy, and the coefficient of thermal expansion of the silicone rubber. In addition, Table 1 shows the results of the reliability of the semiconductor device manufactured using this composition.

[Comparative Example 3] The spherical silica fine powder prepared in Example 2 was synthesized by the sol-gel method instead of the spherical silica fine powder, calcined, and the surface thereof was treated with 3-glycidoxypropyltrimethoxysilane. Powder (ratio of the content of isolated silanol groups to the content of internal silanol groups = 0.
A liquid silicone rubber composition was prepared in the same manner as in Example 2 except that the same amount was used (001; average particle size = 2.0 μm). Table 1 shows the viscosity of this composition, the value showing thixotropy, and the coefficient of thermal expansion of the silicone rubber. In addition, Table 1 shows the results of the reliability of the semiconductor device manufactured using this composition.

[Comparative Example 4] In Comparative Example 3, the content of the spherical silica fine powder was set to 25 parts by weight, and dimethylpolysiloxane 65 capped with dimethylvinylsiloxy groups at both molecular chain ends was used.
% By weight and (CH ₂ = CH) (CH ₃ ) ₂ SiO _1/2 units and (CH ₃ ).
_A liquid silicone rubber composition was prepared in the same manner as in Comparative Example 3 except that the content of the mixture of 35 wt% of organopolysiloxane resin composed of ₃ SiO _1/2 units and SiO _4/2 units was 70 parts by weight. Prepared. Table 1 shows the viscosity of this composition, the value showing thixotropy, and the coefficient of thermal expansion of the silicone rubber. In addition, Table 1 shows the results of the reliability of the semiconductor device manufactured using this composition.

[0042]

[Table 1]

[0043]

EFFECTS OF THE INVENTION The curable liquid silicone composition of the present invention is good because it contains a large amount of fine silica powder to reduce the coefficient of thermal expansion of the cured silicone, but the viscosity increase due to thixotropy is suppressed. It is characterized by having excellent fluidity and impregnation. Further, the semiconductor device of the present invention is characterized by having excellent reliability because the semiconductor element is coated with such a curable liquid silicone composition.

[Brief description of drawings]

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

FIG. 2 is a cross-sectional view of a semiconductor device which is an example of the present invention.

[Explanation of symbols]

1 Semiconductor element 2 circuit board 3 circuit wiring 4 wires 5 External lead 6 Cured product of curable liquid silicone composition 7 Frame material 8 bumps

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Mine victory             2-2 Chikusaigan, Ichihara-shi, Chiba Toray Dow             Corning Silicone Co., Ltd. R & D             In headquarters F-term (reference) 4J002 CP041 CP141 DA117 DD077                       DJ016 FD147 GQ05                 4M109 AA01 BA03 CA02 CA05 CA06                       DB07 EA10 EB13 EC04 EE20                       GA02

Claims (8)

[Claims] 1. A curable liquid silicone composition containing fine silica powder, wherein the ratio of the content of isolated silanol groups to the content of internal silanol groups of the fine silica powder is 0.01 or more. A characteristic curable liquid silicone composition. 2. The silica fine powder has an average particle size of 0.1 to 20 μm.
The curable liquid silicone composition according to claim 1, which is a spherical silica fine powder of m. 3. The curable liquid silicone composition according to claim 1, wherein the silica fine powder is a fine powder obtained by detonating metallic silicon dust in an atmosphere containing oxygen. 4. A curable liquid silicone composition comprising:
The curable liquid silicone composition according to claim 1, wherein the content of the fine silica powder is 10 to 500 parts by weight with respect to 100 parts by weight of the main component organopolysiloxane. 5. The curable liquid silicone composition according to claim 1, wherein the curable liquid silicone composition is a hydrosilylation reaction curable liquid silicone composition. 6. A hydrosilylation-curable liquid silicone composition, wherein (A) 100 parts by weight of a liquid organopolysiloxane having at least two alkenyl groups bonded to silicon atoms in one molecule, (B) bonded to silicon atoms. Liquid organopolysiloxane having at least two hydrogen atoms in one molecule, 0.001 to 100 parts by weight, (C) metal catalyst for hydrosilylation reaction From 10 to 500 parts by weight of silica fine powder in which the ratio of the content of the isolated silanol group to the content of the internal silanol group is 0.01 or more (amount of 0.01 to 1,000 ppm in unit), and (D) the content of the internal silanol group. Curable liquid silicone composition according to claim 5, characterized in that it is at least at least one. 7. The curable liquid silicone composition according to claim 6, wherein the component (D) is mixed in advance with all or part of the component (A). 8. A semiconductor device comprising a semiconductor element coated with the curable liquid silicone composition according to claim 1. Description: