Single-component organic silicon adhesive for chip packaging and preparation method thereof

Abstract

The invention discloses a single-component organic silicon adhesive for chip packaging and a preparation method of the single-component organic silicon adhesive. The organic silicon adhesive is prepared from 8 to 15 parts of vinyl silicone oil, 0.5 to 2 parts of hydrogen-containing silicone oil, 75 to 90 parts of aluminum oxide filler, 0.05 to 0.2 part of filler treating agent, 0.2 to 0.5 part of platinum catalyst, 02 to 0.5 part of platinum catalyst inhibitor, 2 to 10 parts of silane coupling agent and 0.1 to 0.2 part of coloring agent. The single-component organic silicon adhesive can be cured at room temperature, can be cured in an accelerated manner after being heated, also has good adhesion, and can be used for adhering an electronic device protection cover and a substrate, so that an electronic device is isolated from the outside and is protected from being influenced by external impurities, and the reliability of the electronic device is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of chip packaging, and particularly relates to a one-component silicone adhesive for chip packaging and a preparation method thereof. Background Art

[0002] In recent years, the electronics industry has developed rapidly, and various electronic components have become more and more complex and precise. Moreover, electronic products will continue to develop in the direction of being smaller, lighter, and lower in cost in the future. Therefore, chip packaging technology also needs to be continuously improved. Chip packaging technology is actually to package and protect memory chips to prevent them from contacting the outside world. Impurities, bad gases in the air, and even water vapor can cause corrosion of the precision circuits on the chips, thereby leading to a decline in electrical performance. In the chip packaging process, the adhesive between the substrate and the chip cover plate is particularly important, and the quality of the bonding performance directly affects the service life of the chip. At the same time, with the intelligence and integration of the electronics industry, the power requirements for electronic components are getting higher and higher, while the volume requirements are getting higher and higher. Therefore, the adhesive between the substrate and the chip cover plate also needs to have a certain heat dissipation function. To sum up, the silicone system has become the first choice.

[0003] The addition-curing silicone system is an important type of silicone system, which is mainly composed of vinyl silicone resin, hydrogen-containing silicone resin, cross-linking agent, various fillers, additives, and catalysts, etc. Its main characteristics are: good curing, high strength, less volatilization, small heat release, and excellent heat resistance performance. Compared with the condensation-type silicone system, it has no by-products and does not release small molecular substances such as gases, which can more effectively protect the sealed components and also meet people's requirements for environmental protection. However, the addition-curing silicone resin also has disadvantages. Compared with the condensation-type silicone resin, its bonding performance is poor, and compared with epoxy-based and acrylic-based sealants, there is a problem of poor strength.

[0004] Warpage in electronic packaging is inevitable. Excessive warpage of the cover plate can lead to delamination of the TIM material between the cover plate and the chip, resulting in overheating of the chip and ultimately causing the entire system to fail. High-modulus adhesive can limit the warpage of the chip cover plate to a certain extent. And in order to make the adhesive adapt to the BLT thickness of the thermal interface TIM material to a certain extent, most current packaging processes will perform a rapid curing process before normal curing, which requires the adhesive to build a high strength in a short time. The design life of current electronic products is very long. For example, the design life of personal electronic devices is 5-7 years, the design life of electronic devices in automobiles is 10-15 years, the design life of electronic devices on 5G base stations is also more than 10 years, and the design life of electronic devices in the defense field can reach more than 30 years. Therefore, the requirements for aging reliability are also very strict. To solve the above problems, a high-powder-filled thermally conductive silicone gel with high modulus, good adhesion performance, and capable of building a high strength in a short time is needed as the adhesive for chip packaging. Summary of the Invention

[0005] The present invention provides a one-component silicone adhesive with high modulus, good adhesion performance, and capable of building a high strength in a short time to solve the above problems.

[0006] Another object of the present invention is to provide a preparation method of this one-component silicone adhesive for chip packaging.

[0007] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] A one-component silicone adhesive for chip packaging, comprising the following components in parts by weight: 8-15 parts of vinyl silicone oil, 0.5-2 parts of hydrogen-containing silicone oil composition, 75-90 parts of thermally conductive filler, 0.05-0.2 part of thermally conductive filler treatment agent, 0.2-0.5 part of platinum catalyst, 0.1-0.5 part of platinum catalyst inhibitor, 0.1-5 parts of silane coupling agent, and 0.1-0.2 part of colorant.

[0009] In some specific embodiments, the vinyl silicone oil has a structure as shown in formula (I):

[0010]

[0011] Among them, n is an integer from 1 to 10, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10; this vinyl silicone oil of the present invention is end-vinyl silicone oil. In the present invention, the addition amount of the vinyl silicone oil is 8-15 parts by mass, such as 9, 10, 11, 12, 13, 14, 15 parts by mass.

[0012] In a preferred embodiment, the viscosity of the vinyl silicone oil at room temperature (25 °C) is 25-50000 mPa·s, such as 50 mPa·s, 100 mPa·s, 200 mPa·s, 350 mPa·s, 500 mPa·s, 800 mPa·s, 1000 mPa·s, 5000 mPa·s, 10000 mPa·s, 20000 mPa·s, 30000 mPa·s, 40000 mPa·s, 50000 mPa·s, etc., preferably 100-5000 mPa·s, more preferably 100-1000 mPa·s, and the vinyl mass content is 0.08%-1.70%, such as 0.08%, 0.09%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, etc., preferably 0.32-1.06%, more preferably 0.32-0.70%.

[0013] In some specific embodiments, the hydrogen-containing silicone oil composition is composed of three hydrogen-containing silicone oils with hydrogen contents of 0.05-0.36 wt%, 0.42-0.55 wt%, and 0.77-1.35 wt%, respectively. Among them, the structural formulas of the three hydrogen-containing silicone oils are shown in Formula (II):

[0014]

[0015] Among them, x>0, y>0, 0<x + y<20, and both x and y are integers. For example, x and y are each independently selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, etc., and at the same time satisfy 0<x + y<20. In the present invention, the addition amount of the hydrogen-containing silicone oil composition is 0.5-2 parts by mass, such as 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2 parts by mass.

[0016] In a preferred embodiment, the three hydrogen-containing silicone oils in the hydrogen-containing silicone oil composition are in the following weight parts:

[0017] 20-35 parts of the hydrogen-containing silicone oil with a hydrogen content of 0.05-0.36%, such as 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35 parts, etc.;

[0018] 35 - 55 parts of hydrogen - containing silicone oil with a hydrogen content of 0.42 - 0.55%, such as 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55 parts, etc.;

[0019] 25 - 45 parts of hydrogen - containing silicone oil with a hydrogen content of 0.77 - 1.35%, such as 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45 parts, etc.

[0020] In some specific embodiments, the molar ratio of Si - H in the hydrogen - containing silicone oil composition to vinyl in the vinyl silicone oil is 0.8 - 2.0:1, such as 0.8:1, 0.9:1, 1:1, 1.1:1, 1.2:1, 1.3:1, 1.4:1, 1.5:1, 1.6:1, 1.7:1, 1.8:1, 1.9:1, 2:1, and preferably 0.8 - 1.5:1. Among them, the Si - H in the hydrogen - containing silicone oil composition refers to the Si - H bond connected to the Si atom on the main chain in formula (II); the vinyl in the vinyl silicone oil refers to the terminal vinyl in formula (I).

[0021] In the present invention, it is preferred to use three hydrogen - containing silicone oils with different hydrogen contents in combination, which can build its bonding strength in a short time, make the reaction between vinyl and Si - H more sufficient, have a high cross - linking density after complete curing, can reach a very high modulus, and also have a very high bonding strength after undergoing high - temperature and high - temperature and high - humidity reliability tests.

[0022] In some specific embodiments, the heat - conducting filler is a component that can impart heat conductivity to the silicone rubber cured product obtained by curing the adhesive composition of the present invention. It is preferably a powder, and its examples include: fine metal powders such as gold, silver, nickel, and copper; fine powders obtained by depositing or electroplating metals (such as gold, silver, nickel, or copper) on the surface of fine powders (such as ceramics, glass, quartz, or organic resins); metal compounds such as alumina, aluminum nitride, or zinc oxide, and mixtures of two or more of them.

[0023] In some preferred embodiments, the thermal conductive filler is selected from one or more of spherical alumina or amorphous alumina; preferably, the particle size of the spherical alumina is 5-100 μm, such as 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 70 μm, 80 μm, 90 μm, etc., preferably 5-55 μm, and the particle size of the amorphous alumina is 0.1-20 μm, such as 0.1 μm, 0.2 μm, 0.3 μm, 0.4 μm, 0.5 μm, 0.8 μm, 1 μm, 2 μm, 5 μm, 8 μm, 10 μm, 13 μm, 15 μm, 18 μm, 20 μm, etc., preferably 0.3-10 μm. In the present invention, the addition amount of the thermal conductive filler is 75-90 parts by mass, such as 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90 parts by mass.

[0024] Specifically, for example, the thermal conductive filler is selected from one or a mixture of spherical alumina powder with a particle size of 5-100 μm and amorphous alumina powder with a particle size of 0.1-20 μm, preferably a mixture of spherical alumina with a particle size of 5-55 μm and amorphous alumina with a particle size of 0.3-10 μm.

[0025] In the present invention, it is preferred to mix alumina fillers with different particle sizes and different morphologies, which can make the powder disperse more fully, the large and small fillers fill each other, form a more smooth thermal conduction path, and improve the thermal conductivity; and the thickness of the adhesive layer can be controlled to a certain level.

[0026] In some specific embodiments, the thermal conductive filler treatment agent is selected from one or more of 3-chloropropyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltrichlorosilane, 3-methacryloxypropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, preferably vinyltrimethoxysilane. In the present invention, the addition amount of the thermal conductive filler treatment agent is 0.05-0.2 parts by mass, such as 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.2 parts by mass.

[0027] In the present invention, the heat-conducting filler is surface-treated with the said heat-conducting filler treating agent. Preferably, the addition amount of the heat-conducting filler treating agent is 0.6‰ - 1.5‰ of the mass parts of the heat-conducting filler, such as 0.6‰, 0.7‰, 0.8‰, 0.9‰, 1.0‰, 1.1‰, 1.2‰, 1.3‰, 1.4‰, 1.5‰, etc. The treating temperature for surface-treating the heat-conducting filler is 55 - 120°C, such as 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, etc. The process of surface-treating the heat-conducting filler generally involves mixing the heat-conducting filler treating agent with the said heat-conducting filler and stirring at the aforementioned temperature to carry out the modification reaction process.

[0028] In the present invention, through the introduction of heat-conducting filler treating agents such as vinyltrimethoxysilane, the hydroxyl groups on the surface of the heat-conducting filler can be modified, the wettability of the resin to the filler can be improved, the addition amount of the filler can be increased, the viscosity of the system can be reduced, and the processing performance can be improved.

[0029] In some specific embodiments, the silane coupling agent is one or more of vinyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, 3-(methacryloyloxy)propyltrimethoxysilane, 3-(acryloyloxy)propyltrimethoxysilane, or mercaptopropyltriethoxysilane, preferably 3-glycidoxypropyltrimethoxysilane. In the present invention, the addition amount of the silane coupling agent is 0.1 - 5 mass parts, such as 0.1, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5 mass parts.

[0030] In some specific embodiments, the platinum catalyst is a Karstedt-type platinum catalyst with a platinum content of 1000 - 6000 ppm, such as 2000 ppm, 3000 ppm, 4000 ppm, 5000 ppm, 6000 ppm, etc. In the present invention, the addition amount of the platinum catalyst is 0.2 - 0.5 mass parts, such as 0.2, 0.3, 0.4, 0.5 mass parts, etc.

[0031] In some specific embodiments, the platinum catalyst inhibitor is selected from one or more of 1-ethynyl-1-cyclohexanol, 2-methyl-3-butyn-2-ol, 3-methyl-1-pentyn-3-ol, 2-phenyl-3-butyn-2-ol, preferably 2-phenyl-3-butyn-2-ol. In the present invention, the addition amount of the platinum catalyst inhibitor is 0.1 - 0.5 mass parts, such as 0.2, 0.3, 0.4, 0.5 mass parts, etc.

[0032] In some specific embodiments, the colorant is, for example, a black paste, such as RTV-B01 of Pinle (Shanghai) New Material Technology Co., Ltd., but not limited to this manufacturer. It can also be color pastes or colorants of other colors as needed. In the present invention, the addition amount of the colorant is 0.1 - 0.2 parts by mass, for example, 0.15 parts by mass.

[0033] On the other hand of the present invention, the preparation method of the one-component silicone adhesive for chip packaging described above includes the following steps:

[0034] 1) Base glue preparation:

[0035] Mix a part of vinyl silicone oil, a part of thermal conductive filler, and a thermal conductive filler treatment agent by stirring. Add the remaining thermal conductive filler in batches and stir and mix; heat up to treat the surface of the thermal conductive filler for a period of time, and then perform vacuum treatment to remove the unreacted thermal conductive filler treatment agent to obtain the base glue;

[0036] 2) Adhesive preparation:

[0037] Add the base glue obtained in step 1), the remaining vinyl silicone oil, a platinum catalyst inhibitor into a homogenizer, heat up and stir. After mixing evenly, cool down to room temperature, add a silane coupling agent, a hydrogen-containing silicone oil composition, and a colorant, and stir and mix evenly; then add a platinum catalyst and stir and mix evenly, perform vacuum degassing, and store in a sealed state at low temperature after discharging to obtain the one-component silicone adhesive for chip packaging.

[0038] In some specific embodiments, the stirring speed for stirring and mixing in step 1) is 50 - 500 rpm, such as 100 rpm, 150 rpm, 200 rpm, 250 rpm, 300 rpm, 350 rpm, 400 rpm, 450 rpm, 500 rpm, etc., and the stirring time is 10 - 40 min, such as 20 min, 30 min, 40 min, etc.;

[0039] The temperature for heating up to treat the surface of the thermal conductive filler is 50 - 80 °C, such as 60 °C, 65 °C, 70 °C, 75 °C, 80 °C, etc., and the treatment time is 30 - 90 min, such as 40 min, 50 min, 60 min, 70 min, 80 min, 90 min, etc.;

[0040] The temperature for vacuum treatment is 100 - 130 °C, such as 110 °C, 120 °C, 130 °C, etc., and the vacuum time is 30 - 90 min, such as 40 min, 50 min, 60 min, 70 min, 80 min, 90 min, etc.

[0041] In some specific embodiments, in step 2), the temperature for heating and stirring is raised to 60 - 80°C, such as 70°C, the stirring speed is 15 - 200 rpm, such as 20 rpm, 50 rpm, 80 rpm, 100 rpm, 130 rpm, 150 rpm, 180 rpm, 200 rpm, etc., and the stirring time is 10 - 40 min, such as 10 min, 20 min, 30 min, 40 min, etc.;

[0042] The stirring speed for uniformly stirring and mixing is 15 - 200 rpm, such as 20 rpm, 50 rpm, 80 rpm, 100 rpm, 130 rpm, 150 rpm, 180 rpm, 200 rpm, etc., and the stirring time is 10 - 40 min, such as 10 min, 20 min, 30 min, 40 min, etc.; the time for vacuum degassing is 10 - 30 min, such as 10 min, 20 min, 30 min, etc.

[0043] In a preferred embodiment, the method for preparing the one - component silicone adhesive for chip packaging described above includes the following steps:

[0044] (1) Base gum preparation:

[0045] Put the partial vinyl silicone oil, partial alumina powder, and filler treatment agent into a double - planetary mixer, stir at 50 - 500 rpm for 10 - 40 min, then add the remaining alumina powder in batches and stir at 50 - 500 rpm for 10 - 40 min. Raise the temperature to 50 - 80°C to treat the surface of alumina, and the treatment time is 30 - 90 min. Then evacuate under vacuum at 100 - 130°C for 30 - 90 min to remove the unreacted treatment agent.

[0046] (2) Adhesive preparation:

[0047] At room temperature, add 75 - 98 parts of the base gum, 1 - 2 parts of vinyl silicone oil, 0.2 - 0.5 part of platinum catalyst inhibitor into a Zhongyi homogenizer HV180, raise the temperature to 60 - 80°C, stir at 15 - 200 rpm for 10 - 40 min, after mixing evenly, cool down to room temperature, add 0.1 - 5.0 parts of silane coupling agent, 0.5 - 1.0 part of hydrogen - containing silicone oil, 0.1 - 0.2 part of colorant at room temperature, stir at 15 - 200 rpm for 10 - 40 min, and mix evenly. Finally, add 0.1 - 0.5 part of platinum catalyst, stir at 15 - 200 rpm for 10 - 40 min, vacuum degas for 10 - 30 min, and store the one - component silicone adhesive for chip packaging in a sealed manner at low temperature after discharging.

[0048] Compared with the prior art, the present invention has the following beneficial effects:

[0049] The one-component silicone adhesive for chip packaging of the present invention can be cured at room temperature and the curing can be accelerated by heating. After complete curing, it has a high cross-linking density, can reach a very high modulus, and also has a very high bonding strength after undergoing high-temperature and high-temperature high-humidity reliability tests. Specific Embodiments

[0050] The present invention will be further described below through specific embodiments. The embodiments described in the present invention are only for the illustration of the present invention and do not limit the scope of the present invention.

[0051] The main raw materials used in the following examples are sourced as follows:

[0052] The spherical alumina powder used is BAK-15, and the manufacturer is Baitu New Materials Technology Co., Ltd.;

[0053] The amorphous alumina powder used is ALM-41-01, and the manufacturer is Sumitomo Chemical Co., Ltd.;

[0054] The methyl-terminated vinyl silicone oil used is Vi500E, and the manufacturer is Zhejiang Runhe New Materials Co., Ltd.;

[0055] The vinyltrimethoxysilane used is manufactured by Shandong Chenguang & Guike New Materials Co., Ltd.;

[0056] The vinyltriethoxysilane used is manufactured by Shandong Chenguang & Guike New Materials Co., Ltd.;

[0057] The 3-methacryloxypropyltrimethoxysilane used is manufactured by Shandong Chenguang & Guike New Materials Co., Ltd.;

[0058] The end-methyl hydrogen-containing silicone oil used is H510, and the manufacturer is Zhejiang Runhe New Materials Co., Ltd.;

[0059] The 3-glycidoxypropyltrimethoxysilane used is manufactured by Shandong Chenguang & Guike New Materials Co., Ltd.;

[0060] The γ-aminopropyltrimethoxysilane used is manufactured by Hubei Jianghan New Materials Co., Ltd.;

[0061] The platinum catalyst used is Pt5000, and the manufacturer is Sino-Platinum Metals Co., Ltd.;

[0062] The 2-phenyl-3-butyn-2-ol used is manufactured by Aladdin Reagent (Shanghai) Co., Ltd.;

[0063] The 1-alkynyl-1-cyclohexanol used is manufactured by Aladdin Reagent (Shanghai) Co., Ltd.;

[0064] The black paste used is RTV-B01, and the manufacturer is Pinle (Shanghai) New Material Technology Co., Ltd.

[0065] Preparation Examples: Preparation of Base Rubbers A, B, and C

[0066] Place 436 g of methyl vinyl silicone oil with a viscosity of 500 mPa·s and a vinyl content of 0.42%, 3.2 g of vinyltrimethoxysilane, and 859.5 g of amorphous alumina powder with a particle size of 2.2 μm in a double planetary stirring kettle, and stir and mix for 60 min under the conditions of a stirring speed of 15 rpm and a dispersion speed of 150 rpm. After stirring evenly, add another 859.5 g of amorphous alumina powder with a particle size of 2.2 μm, and stir and mix for 60 min under the conditions of a stirring speed of 15 rpm and a dispersion speed of 150 rpm. After stirring evenly, add 859.5 g of spherical alumina powder with a particle size of 15 μm, and stir and mix for 60 min under the conditions of a stirring speed of 15 rpm and a dispersion speed of 150 rpm. After stirring evenly, add another 859.5 g of spherical alumina powder with a particle size of 15 μm, and stir and mix for 60 min under the conditions of a stirring speed of 15 rpm and a dispersion speed of 150 rpm. After all the powder materials are mixed evenly, raise the temperature to 80 °C and keep it constant at this temperature for 30 min. Then raise the temperature to 100 °C and evacuate for 30 min. After cooling, break the vacuum, discharge the material, and store it sealed to obtain base rubber A.

[0067] Place 436 g of methyl vinyl silicone oil with a viscosity of 500 mPa·s and a vinyl content of 0.42%, 3.2 g of vinyltriethoxysilane, and 859.5 g of amorphous alumina powder with a particle size of 2.2 μm in a double planetary stirring kettle, and stir and mix for 30 min under the conditions of a stirring speed of 45 rpm and a dispersion speed of 300 rpm. After stirring evenly, add another 859.5 g of amorphous alumina powder with a particle size of 2.2 μm, and stir and mix for 30 min under the conditions of a stirring speed of 45 rpm and a dispersion speed of 300 rpm. After stirring evenly, add 859.5 g of spherical alumina powder with a particle size of 15 μm, and stir and mix for 30 min under the conditions of a stirring speed of 45 rpm and a dispersion speed of 300 rpm. After stirring evenly, add another 859.5 g of spherical alumina powder with a particle size of 15 μm, and stir and mix for 30 min under the conditions of a stirring speed of 45 rpm and a dispersion speed of 300 rpm. After all the powder materials are mixed evenly, raise the temperature to 80 °C and keep it constant at this temperature for 30 min. Then raise the temperature to 100 °C and evacuate for 30 min. After cooling, break the vacuum, discharge the material, and store it sealed to obtain base rubber B.

[0068] 436 g of methyl vinyl silicone oil with a viscosity of 500 mPa·s and a vinyl content of 0.42%, 3.2 g of 3-methacryloxypropyltrimethoxysilane, and 859.5 g of amorphous alumina powder with a particle size of 2.2 μm were placed in a double planetary stirring kettle and stirred and mixed for 15 min under the conditions of a stirring speed of 70 rpm and a dispersion speed of 500 rpm. After stirring evenly, 859.5 g of amorphous alumina powder with a particle size of 2.2 μm was added and stirred and mixed for 15 min under the conditions of a stirring speed of 70 rpm and a dispersion speed of 500 rpm. After stirring evenly, 859.5 g of spherical alumina powder with a particle size of 15 μm was added and stirred and mixed for 15 min under the conditions of a stirring speed of 70 rpm and a dispersion speed of 500 rpm. After stirring evenly, 859.5 g of spherical alumina powder with a particle size of 15 μm was added and stirred and mixed for 15 min under the conditions of a stirring speed of 70 rpm and a dispersion speed of 500 rpm. After all the powder materials were mixed evenly, the temperature was raised to 80 °C and kept constant at this temperature for 30 min. Then the temperature was raised to 100 °C and vacuumed for 30 min. After cooling, the vacuum was broken, and after discharging, it was sealed and stored to obtain base rubber C.

[0069] Example 1

[0070] At room temperature, 96.93 g of base rubber A, 0.860 g of methyl vinyl silicone oil with a viscosity of 500 mPa·s and a vinyl content of 0.42%, and 0.259 g of 2-phenyl-3-butyn-2-ol were placed in a 300 mL straight bottle and heated at 70 °C for 30 min, and then homogenized at 1200 rpm for 60 s. Then 0.5 g of 3-glycidoxypropyltrimethoxysilane, 0.263 g of end-methyl hydrogen-containing silicone oil with a hydrogen content of 0.18%, 0.473 g of end-methyl hydrogen-containing silicone oil with a hydrogen content of 0.55%, 0.315 g of end-methyl hydrogen-containing silicone oil with a hydrogen content of 1.00%, and 0.1 g of black paste were added and homogenized at 1200 rpm for 60 s, and this was repeated 2 times. Then 0.3 g of a platinum catalyst with a platinum content of 3000 ppm was added and homogenized at 1200 rpm for 60 s, and this was repeated 2 times. After discharging, it was sealed and stored to obtain Example 1. The vinyl to silicon-hydrogen ratio of Example 1 was: 1.044.

[0071] Example 2

[0072] At room temperature, take 96.93 g of base gum B, 1.001 g of methyl-terminated vinyl silicone oil with a viscosity of 500 mPa·s and a vinyl content of 0.42%, and 0.259 g of 2-phenyl-3-butyn-2-ol. Place them in a 300 mL straight-sided bottle and heat at 70 °C for 30 min, then use a homogenizer at 1200 rpm for 60 s. Then add 0.5 g of 3-glycidoxypropyltrimethoxysilane, 0.180 g of end-methyl hydrogen-containing silicone oil with a hydrogen content of 0.18%, 0.320 g of end-methyl hydrogen-containing silicone oil with a hydrogen content of 0.55%, 0.410 g of end-methyl hydrogen-containing silicone oil with a hydrogen content of 1.00%, and 0.1 g of black paste. Use a homogenizer at 1200 rpm for 60 s and repeat 2 times. Then add 0.3 g of a platinum catalyst with a platinum content of 3000 ppm and use a homogenizer at 1200 rpm for 60 s and repeat 2 times. After discharging, seal and store to obtain Example 2. The vinyl-to-silicon-hydrogen ratio of Example 2 is: 1.033.

[0073] Example 3

[0074] At room temperature, take 96.93 g of base gum B, 0.760 g of methyl-terminated vinyl silicone oil with a viscosity of 500 mPa·s and a vinyl content of 0.42%, and 0.259 g of 2-phenyl-3-butyn-2-ol. Place them in a 300 mL straight-sided bottle and heat at 70 °C for 30 min, then use a homogenizer at 1200 rpm for 60 s. Then add 0.5 g of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 0.403 g of end-methyl hydrogen-containing silicone oil with a hydrogen content of 0.18%, 0.460 g of end-methyl hydrogen-containing silicone oil with a hydrogen content of 0.55%, 0.288 g of end-methyl hydrogen-containing silicone oil with a hydrogen content of 1.00%, and 0.1 g of black paste. Use a homogenizer at 1200 rpm for 60 s and repeat 2 times. Then add 0.3 g of a platinum catalyst with a platinum content of 3000 ppm and use a homogenizer at 1200 rpm for 60 s and repeat 2 times. After discharging, seal and store to obtain Example 3. The vinyl-to-silicon-hydrogen ratio of Example 3 is: 1.032.

[0075] Example 4

[0076] At room temperature, 96.93 g of base gum C with a viscosity of 500 mPa·s, 0.860 g of methyl-terminated vinyl silicone oil with a vinyl content of 0.42%, and 0.259 g of 1-ethynyl-1-cyclohexanol were placed in a 300 mL straight-sided bottle and heated at 70 °C for 30 min, then homogenized at 1200 rpm for 60 s. Then, 0.5 g of γ-aminopropyltrimethoxysilane, 0.210 g of end-methyl hydrogen-containing silicone oil with a hydrogen content of 0.18%, 0.578 g of end-methyl hydrogen-containing silicone oil with a hydrogen content of 0.55%, 0.263 g of end-methyl hydrogen-containing silicone oil with a hydrogen content of 1.00%, and 0.1 g of black paste were added and homogenized at 1200 rpm for 60 s, and this was repeated 2 times. Then, 0.3 g of a platinum catalyst with a platinum content of 3000 ppm was added and homogenized at 1200 rpm for 60 s, and this was repeated 2 times. After discharging, it was sealed and stored to obtain Example 4. The vinyl-to-silicon-hydrogen ratio of Example 4 was: 1.037.

[0077] Comparative Example 1

[0078] Compared with Example 1, 0 g of methyl-terminated vinyl silicone oil with a viscosity of 500 mPa·s and a vinyl content of 0.42%, 3.381 g of end-methyl hydrogen-containing silicone oil with a hydrogen content of 0.18%, 0 g of end-methyl hydrogen-containing silicone oil with a hydrogen content of 0.55%, 0 g of end-methyl hydrogen-containing silicone oil with a hydrogen content of 1.00%, and the addition amounts of the remaining raw materials were the same and the rubber mixing process was kept consistent. The vinyl-to-silicon-hydrogen ratio of Comparative Example 1 was: 1.044.

[0079] Comparative Example 2

[0080] Compared with Example 1, 0.761 g of methyl-terminated vinyl silicone oil with a viscosity of 500 mPa·s and a vinyl content of 0.42%, 0 g of end-methyl hydrogen-containing silicone oil with a hydrogen content of 0.18%, 1.129 g of end-methyl hydrogen-containing silicone oil with a hydrogen content of 0.55%, 0 g of end-methyl hydrogen-containing silicone oil with a hydrogen content of 1.00%, and the addition amounts of the remaining raw materials were the same and the rubber mixing process was kept consistent. The vinyl-to-silicon-hydrogen ratio of Comparative Example 1 was: 1.044..

[0081] Comparative Example 3

[0082] Compared with Example 1, 1.301 g of methyl-terminated vinyl silicone oil with a viscosity of 500 mPa·s and a vinyl content of 0.42%, 0 g of end-methyl hydrogen-containing silicone oil with a hydrogen content of 0.18%, 0 g of end-methyl hydrogen-containing silicone oil with a hydrogen content of 0.55%, 0.63 g of end-methyl hydrogen-containing silicone oil with a hydrogen content of 1.00%, and the addition amounts of the remaining raw materials were the same and the rubber mixing process was kept consistent. The vinyl-to-silicon-hydrogen ratio of Comparative Example 1 was: 1.044.

[0083] Comparative Example 4

[0084] Compared with Example 1, 1.301 g of methyl-terminated vinyl silicone oil with a viscosity of 500 mPa·s and a vinyl content of 0.42%, 0 g of end-methyl hydrogen-containing silicone oil with a hydrogen content of 0.18%, 0 g of end-methyl hydrogen-containing silicone oil with a hydrogen content of 0.55%, 0.61 g of end-methyl hydrogen-containing silicone oil with a hydrogen content of 1.00%, the addition amount of Pt5000 is 0.35 g, and the addition amounts of the remaining raw materials are the same and the rubber mixing process is kept consistent. The vinyl-to-silicon-hydrogen ratio of Comparative Example 1 is: 1.044 g.

[0085] Comparative Example 5

[0086] Compared with Example 1, 0.821 g of methyl-terminated vinyl silicone oil with a viscosity of 500 mPa·s and a vinyl content of 0.42%, 0.55 g of end-methyl hydrogen-containing silicone oil with a hydrogen content of 0.18%, 0 g of end-methyl hydrogen-containing silicone oil with a hydrogen content of 0.55%, 0.524 g of end-methyl hydrogen-containing silicone oil with a hydrogen content of 1.00%, and the addition amounts of the remaining raw materials are the same and the rubber mixing process is kept consistent. The vinyl-to-silicon-hydrogen ratio of Comparative Example 1 is: 1.044.

[0087] Main test methods:

[0088] Hardness: Cure the sample with a cylindrical mold with a depth of 5 mm and a diameter of 4 cm, and read the hardness value with a Shore A hardness tester after 2 - 3 seconds.

[0089] Modulus test: Cure the sample with a mold with a length and width of 8 cm and a depth of 2 mm, then polish the front and back sides of the cured sample strip with sandpaper and control the thickness to 1 mm (the positive and negative error is less than 0.05 mm). Use a punch to take a disc with a diameter of 2 mm, and measure the modulus at 25°C and 260°C in the DMA tensile mode.

[0090] Adhesion test under different curing processes:

[0091] Fast curing: Fill the prepared finished glue into a 30 cc glue tube by a centrifuge at 800 rpm for 30 s, use a caulking gun to apply the finished glue onto a 10 mm * 10 mm monocrystalline silicon wafer, press the silicon wafer coated with glue onto the center of a 25 mm * 25 mm nickel-plated copper substrate under a pressure of 20 psi to form a sandwich structure, and place it in an oven at 125°C for 8 min. Use a Nordson 4000PXY push-pull tester to test at a speed of 300 μm / s to obtain the adhesion strength value.

[0092] Normal curing: The prepared finished glue is canned in a 30 cc rubber tube with a centrifuge at 800 rpm for 30 s. The glue is dispensed onto the edge of a copper-nickel plated chip cover plate of 30.5 mm * 30.5 mm using a flat stainless steel needle with an inner diameter of 0.61 mm on a SCITECH SEC-300EDN dispensing machine. Two covers are pasted together and pressed with a pressure of 20 psi to prepare a sandwich structure of copper-nickel plated cover - glue - copper-nickel plated cover, and then placed in an oven at 125 °C for curing for 2 h. The bonding strength value is obtained by testing with a GOTECH GT-AI-3000 tensile machine at a speed of 10 mm / min.

[0093] High-temperature aging test: The sandwich structure of copper-nickel plated cover - glue - copper-nickel plated cover cured normally is placed in a constant-temperature oven at 150 °C for 500 h, and then tested with a GOTECH GT-AI-3000 tensile machine at a speed of 10 mm / min to obtain the bonding strength data after high-temperature aging.

[0094] Humidity and heat aging resistance test: The sandwich structure of copper-nickel plated cover - glue - copper-nickel plated cover cured normally is placed in an aging chamber at 130 °C and 85% humidity for 192 h, and then tested with a GOTECH GT-AI-3000 tensile machine at a speed of 10 mm / min to obtain the bonding strength data after humidity and heat aging resistance.

[0095] In addition, the failure state of the adhesive after fracture was also confirmed. In an ideal bonding state, the failure mode is cohesive failure. "CF" and "AF" in Table 1 and Table 2 below represent the failure modes of "cohesive failure" and "interface peeling", respectively.

[0096] Table 1 Performance comparison of examples

[0097]

[0098] Table 2 Performance comparison of comparative examples

[0099]

[0100]

[0101] Comparative Example 1 only added hydrogen-containing silicone oil with a hydrogen content of 0.18%. Under the condition of the same silicon-hydrogen ratio, the hardness and modulus were low, the crosslinking density was insufficient, and the adhesion strength was low after final curing and after the aging experiment; Comparative Example 2 only added hydrogen-containing silicone oil with a hydrogen content of 0.55%. Similarly, under the condition of the same silicon-hydrogen ratio, the hardness and modulus were also lower than those of the examples, and the moisture and heat resistance and temperature resistance were worse than those of the examples; Comparative Example 3 only added hydrogen-containing silicone oil with a hydrogen content of 1%. Under the condition of the same silicon-hydrogen ratio, the resin was not cured within a short time and could not adapt to the rapid curing production process; Comparative Example 4 was based on Comparative Example 3, and the catalyst dosage was increased in order to accelerate the curing process. However, the increase in the catalyst dosage led to violent polymerization during the polymerization process, which was not alleviated. Therefore, both the adhesion performance and the aging resistance performance were reduced; Comparative Example 5 only added hydrogen-containing silicone oil with a hydrogen content of 0.18% and hydrogen-containing silicone oil with a hydrogen content of 1.00%, and did not add hydrogen-containing silicone oil with a hydrogen content of 0.55%. Under the condition of the same silicon-hydrogen ratio, it had a low strength within a short time, and the adhesion performance after moisture and heat resistance and high temperature resistance was not as good as that of the examples. In Examples 1-4, because three kinds of hydrogen-containing silicone oils with different hydrogen contents were added, the polymerization process was mild, taking into account the rapid curing process, and a high adhesion strength could be obtained in a short time. After final complete curing, the crosslinking degree was high, the adhesion performance was strong, and the aging resistance performance was excellent, and the performance met the requirements for chip packaging.

[0102] The above are only the preferred embodiments of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the method of the present invention, several improvements and supplements can still be made, and these improvements and supplements should also be regarded as the protection scope of the present invention.

Claims

1. A one-component silicone adhesive for chip packaging, characterized in that, it comprises the following components in parts by weight: 8-15 parts of vinyl silicone oil, 0.5-2 parts of hydrogen-containing silicone oil composition, 75-90 parts of heat-conducting filler, 0.05-0.2 parts of heat-conducting filler treatment agent, 0.2-0.5 parts of platinum catalyst, 0.1-0.5 parts of platinum catalyst inhibitor, 0.1-5 parts of silane coupling agent, and 0.1-0.2 parts of coloring agent.

2. The one-component silicone adhesive for chip packaging according to claim 1, characterized in that, the heat-conducting filler is selected from at least one of metal fine powder, powder with a metal layer deposited or electroplated on its surface, and metal compound; preferably, the metal fine powder is selected from any one of gold, silver, nickel or copper; and / or the powder with a metal layer deposited or electroplated on its surface is a powder obtained by depositing or electroplating gold, silver, nickel or copper on the surface of ceramics, glass, quartz or organic resin; and / or the metal compound powder is selected from at least one of alumina powder, aluminum nitride powder or zinc oxide powder; more preferably, the heat-conducting filler is selected from one or more of spherical alumina or amorphous alumina; preferably, the particle size of the spherical alumina is 5-100 μm, preferably 5-55 μm, and the particle size of the amorphous alumina is 0.1-20 μm, preferably 0.3-10 μm.

3. The one-component silicone adhesive for chip packaging according to claim 1, characterized in that, the heat-conducting filler treatment agent is selected from one or more of 3-chloropropyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltrichlorosilane, 3-methacryloxypropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, preferably vinyltrimethoxysilane; preferably, the dosage of the heat-conducting filler treatment agent is 0.6‰-1.5‰ of the mass fraction of the heat-conducting filler, and the treatment temperature is 55-120 °C.

4. The one-component silicone adhesive for chip packaging according to claim 1, the structure of the vinyl silicone oil is shown in formula (I): wherein, n is an integer from 1 to 10; preferably, the viscosity of the vinyl silicone oil at room temperature of 25 °C is 25-50000 mPa·s, preferably 100-5000 mPa·s, more preferably 100-1000 mPa·s, and the mass percentage content of vinyl is 0.08%-1.70%, preferably 0.32-1.06%, more preferably 0.32-0.70%.

5. The one-component silicone adhesive for chip packaging according to claim 1, characterized in that, the hydrogen-containing silicone oil composition is composed of three kinds of hydrogen-containing silicone oils with hydrogen contents of 0.05-0.36 wt%, 0.42-0.55 wt%, and 0.77-1.35 wt% respectively, wherein the structural formulas of the three kinds of hydrogen-containing silicone oils are shown in formula (II): wherein, x>0, y>0, 0<x + y<20, and x and y are both integers. Preferably, the three kinds of hydrogen-containing silicone oils in the hydrogen-containing silicone oil composition are in parts by weight as follows: 20 - 35 parts of hydrogen - containing silicone oil with hydrogen content of 0.05 - 0.36% 35 - 55 parts of hydrogen - containing silicone oil with hydrogen content of 0.42 - 0.55% 25 - 45 parts of hydrogen - containing silicone oil with hydrogen content of 0.77 - 1.35%.

6. The one - component silicone adhesive for chip packaging according to any one of claims 1 to 5, characterized in that, the molar ratio of Si - H in the hydrogen - containing silicone oil composition to vinyl in the vinyl silicone oil is 0.8 - 2.0:1, preferably 0.8 - 1.5:

1.

7. The one - component silicone adhesive for chip packaging according to claim 1, characterized in that, the silane coupling agent is selected from one or more of vinyltriethoxysilane, 2 - (3,4 - epoxycyclohexyl)ethyltrimethoxysilane, 3 - glycidoxypropyltrimethoxysilane, γ - aminopropyltrimethoxysilane, 3 - (methacryloyloxy)propyltrimethoxysilane, 3 - (acryloyloxy)propyltrimethoxysilane, mercaptopropyltriethoxysilane, and preferably 3 - glycidoxypropyltrimethoxysilane.

8. The one - component silicone adhesive for chip packaging according to claim 1, characterized in that, the platinum catalyst is Karstedt - type platinum catalyst with platinum content of 1000 - 6000 ppm; and / or the platinum catalyst inhibitor is selected from one or more of 1 - ethynyl - 1 - cyclohexanol, 2 - methyl - 3 - butyn - 2 - ol, 3 - methyl - 1 - pentyn - 3 - ol, 2 - phenyl - 3 - butyn - 2 - ol, and preferably 2 - phenyl - 3 - butyn - 2 - ol.

9. The preparation method of the one - component silicone adhesive for chip packaging according to any one of claims 1 to 8, characterized in that, comprises the following steps: 1) Base glue preparation: Mix part of vinyl silicone oil, part of heat - conducting filler, and heat - conducting filler treatment agent by stirring. Add the remaining heat - conducting filler in batches and stir - mix; raise the temperature to treat the surface of the heat - conducting filler for a period of time, then conduct vacuum treatment to remove the unreacted heat - conducting filler treatment agent to obtain the base glue; 2) Adhesive preparation: Add the base glue obtained in step 1), the remaining vinyl silicone oil, platinum catalyst inhibitor into a homogenizer, raise the temperature and stir. After mixing evenly, cool to room temperature, add silane coupling agent, hydrogen - containing silicone oil composition and colorant, and stir - mix evenly; then add platinum catalyst and stir - mix evenly, conduct vacuum degassing, and store in a sealed and low - temperature manner after discharging to obtain the one - component silicone adhesive for chip packaging.

10. According to the preparation method described in claim 9, characterized in that, the stirring speed for stirring - mixing in step 1) is 50 - 500 rpm, and the stirring time is 10 - 40 min; and / or the temperature for treating the surface of the heat - conducting filler by raising the temperature in step 1) is 50 - 80 °C, and the treatment time is 30 - 90 min; and / or the temperature for vacuum treatment is 100 - 130 °C, and the vacuum time is 30 - 90 min; Preferably, in step 2), the temperature for raising the temperature and stirring is raised to 60 - 80 °C, the stirring speed is 15 - 200 rpm, and the stirring time is 10 - 40 min; and / or The stirring speed for stirring and mixing evenly is 15 - 200 rpm, and the stirring time is 10 - 40 min; and / or The time for vacuum degassing is 10 - 30 min.

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