A silicon material binder and a method for preparing the same

Abstract

The application relates to the field of binders, and discloses a silicon material binder and a preparation method thereof. The silicon material binder comprises: 100 parts by weight of silicon powder; 3-5 parts by weight of silica sol; 40-60 parts by weight of a solvent; 1-3 parts by weight of a silane coupling agent; 1-3 parts by weight of a thickening agent; 5-10 parts by weight of modified nano-alumina; and 2-5 parts by weight of an organic silicon prepolymer. The modified nano-alumina is nano-alumina treated by a silane coupling agent KH-550, and has a particle size of 10-30 nm. The organic silicon prepolymer is a prepolymer prepared from methyl triethoxysilane and dimethyl diethoxysilane at a molar ratio of 1:(0.8-1.1), and has a weight average molecular weight of 2000-5000. The silicon material binder has good high-temperature compactness and thermal stability, and the silicon material binder has good initial bonding strength.

Description

Technical Field

[0001] This invention relates to the field of adhesives, and more specifically, to a silicon material adhesive and its preparation method. Background Technology

[0002] Silicon, with the chemical symbol Si, is the most produced and widely used semiconductor material. Silicon used in the electronics industry must possess high purity and excellent electrical and mechanical properties. Its production volume and usage are indicators of a country's level of solar energy industry development. Therefore, the production process of silicon materials is also quite important.

[0003] Silicon is a key material in the semiconductor and solar energy fields, and the bonding performance between its components has a significant impact on the reliability and lifespan of devices. Existing silicon material binders mostly use silicon powder with a single particle size or a simple mixture. For example, Chinese patent CN118344815A discloses a silicon material binder and its preparation method, comprising 100 parts by weight of silicon powder, 3-5 parts by weight of silica sol, and 40-60 parts by weight of solvent; the silicon powder is composed of silicon powder with a particle size of 1-5 μm, silicon powder with a particle size of 20-30 μm, and silicon powder with a particle size of 120-130 μm mixed in a weight ratio of 1:(4-10):(10-15). The silicon material binder of the present invention selects silicon powders with different particle sizes for compounding, and improves the compatibility between silicon powders with different particle sizes through scientific proportioning. When dissolved in a solvent, it forms an binder with a certain initial bonding strength. The silicon powder is sintered and melted at high temperature to form a strong and well-sealed bond with the silicon substrate, and the bonding strength is greatly improved.

[0004] However, while the aforementioned adhesives possess a certain bonding strength, they still fall short in terms of density, thermal stability, and thermal shock resistance after high-temperature sintering. Furthermore, the initial bond strength and chemical stability of conventional adhesives at high temperatures need further improvement. Summary of the Invention

[0005] In view of the problems existing in the prior art, the purpose of this invention is to provide a silicon material adhesive with good high-temperature densification and thermal stability, as well as good initial bond strength.

[0006] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a silicon material binder comprising the following components in parts by weight:

[0008] 100 parts by weight of silicon powder;

[0009] 3-5 parts by weight of silica sol;

[0010] 40-60 parts by weight of solvent;

[0011] 1-3 parts by weight of silane coupling agent;

[0012] 1-3 parts by weight of thickener;

[0013] 5-10 parts by weight of modified nano-alumina;

[0014] 2-5 parts by weight of organosilicon prepolymer;

[0015] The modified nano-alumina is nano-alumina surface-treated with silane coupling agent KH-550, and its particle size is 10-30nm;

[0016] The organosilicon prepolymer is a prepolymer prepared by mixing methyltriethoxysilane and dimethyldiethoxysilane in a molar ratio of 1:(0.8-1.1), and its weight-average molecular weight is 2000-5000.

[0017] Furthermore, the silicon powder is composed of silicon powder with a particle size of 3-5 μm, silicon powder with a particle size of 15-20 μm, and silicon powder with a particle size of 80-90 μm mixed in a weight ratio of 1:(2-4):(6-8).

[0018] Furthermore, the silicon powder is composed of silicon powder with a particle size of 3-5 μm, silicon powder with a particle size of 15-20 μm, and silicon powder with a particle size of 80-90 μm mixed in a weight ratio of 1:3:7.

[0019] Furthermore, the modified nano-alumina is prepared by the following method:

[0020] Step 1: Disperse nano-alumina in anhydrous ethanol to form a suspension with a mass concentration of 5-10%;

[0021] Step 2: Under stirring conditions, add 3-8% by weight of silane coupling agent KH-550 dropwise to the suspension;

[0022] Step 3: After the addition is complete, reflux the mixture at 60-80°C for 2-4 hours.

[0023] Step 4: After the reaction is complete, centrifuge, wash the solid product with ethanol 2-3 times, dry it under vacuum at 80-100°C, and grind it to obtain the modified nano alumina.

[0024] Furthermore, the organosilicon prepolymer is a prepolymer prepared by mixing methyltriethoxysilane and dimethyldiethoxysilane in a molar ratio of 1:0.95, and its weight-average molecular weight is 2000-5000.

[0025] Furthermore, the organosilicon prepolymer is prepared by the following method:

[0026] Step 1: Mix methyltriethoxysilane and dimethyldiethoxysilane in a molar ratio of 1:(0.8-1.2);

[0027] Step 2: Under stirring conditions, slowly add catalyst equivalent to 1-2% of the total weight of silane and deionized water equivalent to 1.5-2 times the total volume of silane, and carry out hydrolysis-condensation reaction at 50-70°C for 3-5 hours.

[0028] Step 3: After the reaction is complete, allow the mixture to stand and separate into layers. Remove the lower aqueous phase and wash the upper organic phase with deionized water until neutral. Then, dehydrate the organic silicon prepolymer under reduced pressure for 1-2 hours at 100-120°C and -0.09~-0.1MPa to obtain the organosilicon prepolymer with a weight average molecular weight of 2000-5000.

[0029] Furthermore, the catalyst is hydrochloric acid or p-toluenesulfonic acid.

[0030] Furthermore, the silane coupling agent includes one or more of trimethoxysilane, triethoxysilane, tetramethyl silicate, and tetraethyl silicate.

[0031] Furthermore, the thickener includes one or more of methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, and hydroxypropylmethylcellulose.

[0032] Secondly, the present invention provides a method for preparing the aforementioned silicon material binder, comprising the following steps:

[0033] Step 1: Add the thickener to the solvent and mix well to obtain mixture A;

[0034] Step 2: Mix the silicon powder, silane coupling agent, modified nano-alumina and organosilicon prepolymer evenly to obtain mixture B;

[0035] Step 3: After mixing mixture A and mixture B, add silica sol and mix well to obtain the final product.

[0036] In summary, the solution provided by this invention has the following beneficial effects:

[0037] The silicon material adhesive provided by this invention significantly improves high-temperature densification, thermal stability, and initial bonding strength by optimizing the composition and ratio.

[0038] Based on existing technology, the particle size distribution of silicon powder is further optimized, which effectively fills the voids inside the binder and improves the density after sintering. The introduction of modified nano-alumina enhances the thermal stability of the binder, enabling it to maintain excellent bonding performance even at high temperatures. The addition of organosilicon prepolymer further improves the initial bonding strength of the binder, enabling it to form strong adhesion in the early stages of bonding.

[0039] Furthermore, the method for preparing silicon material binders provided by this invention is simple and easy to implement. After the components are mixed evenly, a high-performance binder can be obtained, which has broad application prospects. Detailed Implementation

[0040] The technical solutions and effects of the present invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely for explaining the invention and are not intended to limit the invention.

[0041] By thoroughly studying existing silicon material adhesive composition schemes, the present invention optimizes the composition and ratio of silicon material adhesives and further introduces modified nano-alumina and organosilicon prepolymers. Through the organic synergistic effect between the two and other components, the thermal stability of the adhesive is effectively enhanced, enabling it to maintain excellent bonding performance at high temperatures and simultaneously improve the initial bonding strength of the adhesive, allowing it to form strong adhesion in the early stages of bonding.

[0042] Accordingly, the present invention provides a specific formulation of a silicon material binder, which is specifically composed of the following components in parts by weight:

[0043] 100 parts by weight of silicon powder;

[0044] 3-5 parts by weight of silica sol;

[0045] 40-60 parts by weight of solvent;

[0046] 1-3 parts by weight of silane coupling agent;

[0047] 1-3 parts by weight of thickener;

[0048] 5-10 parts by weight of modified nano-alumina;

[0049] 2-5 parts by weight of organosilicon prepolymer.

[0050] Furthermore, the silicon powder in this formulation is composed of silicon powder with a particle size of 3-5μm, silicon powder with a particle size of 15-20μm, and silicon powder with a particle size of 80-90μm mixed in a weight ratio of 1:(2-4):(6-8).

[0051] Furthermore, the silica sol in this formulation is a silica sol, wherein the silica content is 45%-55%, preferably 48%, 50%, or 53%; and the silica particle size is between 20-40 nm, preferably 20 nm, 25 nm, or 30 nm. The silica sol is selected from commercially available silica sol products based on the aforementioned preferred parameters.

[0052] Furthermore, the solvent in this formulation is one or more of water or alcohol solvents having 1-4 carbon atoms. Specifically, water is preferred as the solvent in this formulation.

[0053] Furthermore, the silane coupling agent in this formulation includes one or more of trimethoxysilane, triethoxysilane, tetramethyl silicate, and tetraethyl silicate. Specifically, the silane coupling agent in this formulation is preferably triethoxysilane.

[0054] Furthermore, the thickener in this formulation includes one or more of methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, and hydroxypropylmethylcellulose. Specifically, the thickener in this formulation is preferably hydroxyethylcellulose.

[0055] Furthermore, the modified nano-alumina in this formulation is nano-alumina surface-treated with silane coupling agent KH-550, with a particle size of 10-30 nm.

[0056] As further explanation, this modified nano-alumina can be prepared by the following method:

[0057] Step 1: Disperse nano-alumina in anhydrous ethanol to form a suspension with a mass concentration of 5-10%;

[0058] Step 2: Under stirring conditions, add 3-8% by weight of silane coupling agent KH-550 dropwise to the suspension;

[0059] Step 3: After the addition is complete, reflux the mixture at 60-80°C for 2-4 hours.

[0060] Step 4: After the reaction is complete, centrifuge, wash the solid product with ethanol 2-3 times, dry it under vacuum at 80-100°C, and grind it to obtain the modified nano alumina.

[0061] Furthermore, the organosilicon prepolymer in this formulation is a prepolymer prepared by mixing methyltriethoxysilane and dimethyldiethoxysilane in a molar ratio of 1:(0.8-1.1), with a weight-average molecular weight of 2000-5000.

[0062] As further explanation, the organosilicon prepolymer in this scheme can be prepared by the following method:

[0063] Step 1: Mix methyltriethoxysilane and dimethyldiethoxysilane in a molar ratio of 1:(0.8-1.2);

[0064] Step 2: Under stirring conditions, slowly add catalyst equivalent to 1-2% of the total weight of silane and deionized water equivalent to 1.5-2 times the total volume of silane, and carry out hydrolysis-condensation reaction at 50-70°C for 3-5 hours.

[0065] Step 3: After the reaction is complete, allow the mixture to stand and separate into layers. Remove the lower aqueous phase and wash the upper organic phase with deionized water until neutral. Then, dehydrate the organic silicon prepolymer under reduced pressure for 1-2 hours at 100-120°C and -0.09~-0.1MPa to obtain the organosilicon prepolymer with a weight average molecular weight of 2000-5000.

[0066] As a further explanation, the catalyst used in this organosilicon prepolymer preparation scheme is preferably hydrochloric acid or p-toluenesulfonic acid.

[0067] Regarding the specific formulation of the aforementioned silicon material binder, this invention further provides a preparation scheme for preparing the silicon material binder based on this formulation.

[0068] Specifically, the preparation method of the silicon material binder provided in this invention consists of the following steps in sequence:

[0069] Step 1: Add the thickener to the solvent according to the formula ratio and mix well to obtain mixture A;

[0070] Step 2: Mix the silicon powder, silane coupling agent, modified nano-alumina and organosilicon prepolymer evenly according to the formula ratio to obtain mixture B;

[0071] Step 3: After mixing mixture A and mixture B evenly, add silica sol according to the formula ratio and mix evenly to obtain the final product.

[0072] The silicon material binder prepared accordingly has excellent high-temperature densification, thermal stability, and initial bond strength.

[0073] The present invention will be further illustrated below with reference to specific embodiments. These specific embodiments are implemented based on the technical solution of the present invention, and detailed implementation methods and operating procedures are provided. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Experimental methods in the following embodiments that do not specify specific conditions are generally carried out under conventional conditions. Unless otherwise stated, proportions and percentages are by weight.

[0074] Example 1

[0075] This embodiment provides a silicon material adhesive, which specifically comprises the following components in parts by weight:

[0076] 100 parts by weight of silicon powder;

[0077] 3 parts by weight of silica sol;

[0078] 40 parts by weight of solvent;

[0079] 1 part by weight of silane coupling agent;

[0080] 1 part by weight of thickener;

[0081] 5 parts by weight of modified nano-alumina;

[0082] Two parts by weight of organosilicon prepolymer.

[0083] In this example, the silicon powder is composed of silicon powder with a particle size of 3-5 μm, silicon powder with a particle size of 15-20 μm, and silicon powder with a particle size of 80-90 μm mixed in a weight ratio of 1:2:6.

[0084] In this example, the silica sol is a silica sol, wherein the silica content is 45%-55%, preferably 48%, 50%, or 53%; and the silica particle size is between 20-40 nm, preferably 20 nm, 25 nm, or 30 nm. The silica sol is a commercially available silica sol product selected based on the aforementioned preferred parameters.

[0085] In this example, water is the preferred solvent.

[0086] The silane coupling agent in this example is triethoxysilane.

[0087] The thickener used in this example is hydroxyethyl cellulose.

[0088] The modified nano-alumina in this example is nano-alumina surface-treated with silane coupling agent KH-550, with a particle size of 10-30 nm. This modified nano-alumina is prepared by the following method:

[0089] Step 1: Disperse nano-alumina in anhydrous ethanol to form a suspension with a mass concentration of 5%.

[0090] Step 2: Under stirring conditions, add 3% by weight of nano-alumina silane coupling agent KH-550 dropwise to the suspension;

[0091] Step 3: After the addition is complete, reflux the mixture at 60°C for 4 hours.

[0092] Step 4: After the reaction is complete, centrifuge, wash the solid product with ethanol 2-3 times, dry it under vacuum at 80°C, and grind it to obtain the modified nano alumina.

[0093] The organosilicon prepolymer in this example is a prepolymer prepared from methyltriethoxysilane and dimethyldiethoxysilane in a molar ratio of 1:0.8, with a weight-average molecular weight of 2000-5000; and it is prepared by the following method:

[0094] Step 1: Mix methyltriethoxysilane and dimethyldiethoxysilane in a molar ratio of 1:0.8;

[0095] Step 2: Under stirring conditions, slowly add catalyst equivalent to 1% of the total weight of silane and deionized water equivalent to 1.5 times the total volume of silane, and carry out hydrolysis condensation reaction at 50°C for 5 hours.

[0096] Step 3: After the reaction is complete, allow the mixture to stand and separate into layers. Remove the lower aqueous phase and wash the upper organic phase with deionized water until neutral. Then, dehydrate it under reduced pressure at 100°C and -0.09 MPa for 2 hours to obtain the organosilicon prepolymer with a weight average molecular weight of 2000-5000.

[0097] The catalyst used in this example is p-toluenesulfonic acid.

[0098] In this example, the silicon material binder is prepared based on the above silicon material binder formulation using the following preparation method:

[0099] Step 1: Add the thickener to the solvent according to the specified ratio and mix well to obtain mixture A;

[0100] Step 2: Mix the silicon powder, silane coupling agent, modified nano-alumina and organosilicon prepolymer evenly according to the formula to obtain mixture B;

[0101] Step 3: After mixing mixture A and mixture B evenly, add silica sol according to the ratio and mix evenly to obtain the final product.

[0102] Silicon material binder sample 1 was thus prepared.

[0103] Example 2

[0104] This embodiment provides a silicon material adhesive, which differs from Embodiment 1 only in that it comprises the following components in parts by weight:

[0105] 100 parts by weight of silicon powder;

[0106] 4 parts by weight of silica sol;

[0107] 50 parts by weight of solvent;

[0108] 2 parts by weight of silane coupling agent;

[0109] 2 parts by weight of thickener;

[0110] 7.5 parts by weight of modified nano-alumina;

[0111] 3.5 parts by weight of organosilicon prepolymer.

[0112] This example yields silicon material binder sample 2.

[0113] Example 3

[0114] This embodiment provides a silicon material adhesive, which differs from Embodiment 1 only in that it includes the following components in parts by weight:

[0115] 100 parts by weight of silicon powder;

[0116] 5 parts by weight of silica sol;

[0117] 60 parts by weight of solvent;

[0118] 3 parts by weight of silane coupling agent;

[0119] 3 parts by weight of thickener;

[0120] 10 parts by weight of modified nano-alumina;

[0121] 5 parts by weight of organosilicon prepolymer.

[0122] This example yields silicon material binder sample 3.

[0123] Example 4

[0124] This embodiment provides a silicon material adhesive, which differs from Embodiment 1 only in that:

[0125] The silicon powder is composed of silicon powder with a particle size of 3-5μm, silicon powder with a particle size of 15-20μm and silicon powder with a particle size of 80-90μm in a weight ratio of 1:3:7.

[0126] This example yields silicon material binder sample 4.

[0127] Example 5

[0128] This embodiment provides a silicon material adhesive, which differs from Embodiment 1 only in that:

[0129] The silicon powder is composed of silicon powder with a particle size of 3-5μm, silicon powder with a particle size of 15-20μm and silicon powder with a particle size of 80-90μm in a weight ratio of 1:4:8.

[0130] This example yields silicon material binder sample 5.

[0131] Example 6

[0132] This embodiment provides a silicon material adhesive, which differs from Embodiment 1 only in that:

[0133] The modified nano-alumina is nano-alumina with a particle size of 10-30 nm, which has been surface-treated with silane coupling agent KH-550, and is prepared by the following method:

[0134] Step 1: Disperse nano-alumina in anhydrous ethanol to form a suspension with a mass concentration of 7.5%;

[0135] Step 2: Under stirring conditions, add 5% by weight of nano-alumina silane coupling agent KH-550 dropwise to the suspension;

[0136] Step 3: After the addition is complete, reflux the mixture at 70°C for 3 hours.

[0137] Step 4: After the reaction is complete, centrifuge, wash the solid product with ethanol 2-3 times, dry it under vacuum at 90°C, and grind it to obtain the modified nano alumina.

[0138] This example yields silicon material binder sample 6.

[0139] Example 7

[0140] This embodiment provides a silicon material adhesive, which differs from Embodiment 1 only in that:

[0141] The modified nano-alumina is nano-alumina with a particle size of 10-30 nm, which has been surface-treated with silane coupling agent KH-550, and is prepared by the following method:

[0142] Step 1: Disperse nano-alumina in anhydrous ethanol to form a suspension with a mass concentration of 10%;

[0143] Step 2: Under stirring conditions, add 8% by weight of nano-alumina silane coupling agent KH-550 dropwise to the suspension;

[0144] Step 3: After the addition is complete, reflux the mixture at 80°C for 2 hours.

[0145] Step 4: After the reaction is complete, centrifuge, wash the solid product with ethanol 2-3 times, dry it under vacuum at 100°C, and grind it to obtain the modified nano-alumina.

[0146] This example yields silicon material binder sample 7.

[0147] Example 8

[0148] This embodiment provides a silicon material adhesive, which differs from Embodiment 1 only in that:

[0149] The organosilicon prepolymer is a prepolymer prepared from methyltriethoxysilane and dimethyldiethoxysilane in a molar ratio of 1:0.95, with a weight-average molecular weight of 2000-5000. The organosilicon prepolymer in this embodiment is prepared by the following method:

[0150] Step 1: Mix methyltriethoxysilane and dimethyldiethoxysilane in a molar ratio of 1:0.95;

[0151] Step 2: Under stirring conditions, slowly add catalyst equivalent to 1.5% of the total weight of silane and deionized water twice the total volume of silane, and carry out hydrolysis condensation reaction at 60°C for 4 hours.

[0152] Step 3: After the reaction is complete, allow the mixture to stand and separate into layers. Remove the lower aqueous phase and wash the upper organic phase with deionized water until neutral. Then, dehydrate it under reduced pressure at 110°C and -0.1 MPa for 1.5 hours to obtain the organosilicon prepolymer with a weight average molecular weight of 2000-5000.

[0153] The catalyst is p-toluenesulfonic acid.

[0154] This example yields silicon material binder sample 8.

[0155] Example 9

[0156] This embodiment provides a silicon material adhesive, which differs from Embodiment 1 only in that:

[0157] The organosilicon prepolymer is a prepolymer prepared from methyltriethoxysilane and dimethyldiethoxysilane in a molar ratio of 1:1.1, with a weight-average molecular weight of 2000-5000. The organosilicon prepolymer in this embodiment is prepared by the following method:

[0158] Step 1: Mix methyltriethoxysilane and dimethyldiethoxysilane in a molar ratio of 1:1.2;

[0159] Step 2: Under stirring conditions, slowly add catalyst equivalent to 2% of the total weight of silane and deionized water twice the total volume of silane, and carry out hydrolysis condensation reaction at 70°C for 3 hours.

[0160] Step 3: After the reaction is complete, allow the mixture to stand and separate into layers. Remove the lower aqueous phase and wash the upper organic phase with deionized water until neutral. Then, dehydrate it under reduced pressure at 120°C and -0.1 MPa for 1 hour to obtain the organosilicon prepolymer with a weight average molecular weight of 2000-5000.

[0161] The catalyst is p-toluenesulfonic acid.

[0162] This example yields silicon material binder sample 9.

[0163] Comparative Example 1

[0164] This comparative example provides an adhesive comprising 100 parts by weight of silicon powder, 3 parts by weight of silica sol and 40 parts by weight of solvent; the silicon powder is composed of silicon powder with a particle size of 1-5 μm, silicon powder with a particle size of 20-30 μm and silicon powder with a particle size of 120-130 μm in a weight ratio of 1:4:10.

[0165] Among them, the silica sol is selected from commercially available silica sol products based on the aforementioned preferred parameters.

[0166] The silicon material binder is prepared by the following steps: adding silicon powder to a solvent and mixing well, then adding silica sol and mixing well.

[0167] This comparative example prepared a silicon material binder comparative sample 1.

[0168] Comparative Example 2

[0169] This comparative example provides an adhesive that differs from Example 1 only in that:

[0170] The components include the following parts by weight:

[0171] 100 parts by weight of silicon powder;

[0172] 3 parts by weight of silica sol;

[0173] 40 parts by weight of solvent;

[0174] 1 part by weight of silane coupling agent;

[0175] 1 part by weight of thickener;

[0176] Two parts by weight of organosilicon prepolymer.

[0177] This comparative example prepared a silicon material binder comparative sample 2.

[0178] Comparative Example 3

[0179] This comparative example provides an adhesive that differs from Example 1 only in that:

[0180] The components include the following parts by weight:

[0181] 100 parts by weight of silicon powder;

[0182] 3 parts by weight of silica sol;

[0183] 40 parts by weight of solvent;

[0184] 1 part by weight of silane coupling agent;

[0185] 1 part by weight of thickener;

[0186] 5 parts by weight of modified nano-alumina.

[0187] This comparative example prepared a silicon material binder comparative sample 3.

[0188] Comparative Example 4

[0189] This comparative example provides an adhesive that differs from Example 1 only in that:

[0190] The components include the following parts by weight:

[0191] 100 parts by weight of silicon powder;

[0192] 3 parts by weight of silica sol;

[0193] 40 parts by weight of solvent;

[0194] 1 part by weight of silane coupling agent;

[0195] 1 part by weight of thickener.

[0196] This comparative example prepared a silicon material binder comparative sample 4.

[0197] Comparative Example 5

[0198] This comparative example provides an adhesive that differs from Example 1 only in that:

[0199] The silicon powder is composed of silicon powder with a particle size of 1-5 μm, silicon powder with a particle size of 20-30 μm, and silicon powder with a particle size of 120-130 μm mixed in a weight ratio of 1:4:10.

[0200] This comparative example prepared a silicon material binder comparative sample 5.

[0201] Performance testing

[0202] Adhesive samples 1-9 prepared in Examples 1-9 and comparative adhesive samples 1-5 prepared in Comparative Examples 1-5 were taken as test objects and their performance was tested.

[0203] (1) Initial bond strength test: The two silicon wafers are initially bonded together and tested according to GB / T 7124-2008 standard;

[0204] (2) Tensile shear strength test: Two silicon wafers were fused together, and the sample was subjected to tensile shear test at a temperature of 500℃ using a universal testing machine.

[0205] The test results are recorded in Table 1 below.

[0206] Table 1 Performance Test Results

[0207]

[0208] As can be seen from the data in the table above, the initial bond strength and tensile shear strength of the samples prepared in Examples 1-9 of the present invention are significantly higher than those of the comparative samples prepared in all Comparative Examples 1-5. This indicates that the present invention, based on the specific particle size of silicon powder compound, can produce a synergistic effect by introducing modified nano-alumina and organosilicon prepolymer, which together significantly improve the initial bonding performance and final bond strength of the adhesive at high temperature.

[0209] Compared with Comparative Example 2, Example 1 showed a significant improvement in the aforementioned performance. This indicates that the modified nano-alumina plays a key role in improving the high-temperature densification and thermal stability of the binder, with its nanoparticles effectively filling the micropores during the sintering process, thereby enhancing the tensile shear strength.

[0210] Compared with Comparative Example 3, the initial tack strength of Example 1 is significantly improved. This indicates that the silicone prepolymer can effectively improve the rheological properties and initial film-forming ability of the binder, providing higher initial tack strength before sintering through its own viscosity and crosslinking properties.

[0211] Comparative Example 5 used the original patented silicon powder ratio (1:4:10), and although its performance was better than that of the basic Comparative Example 1, it was significantly lower than that of Example 4, which used the new silicon powder ratio (1:3:7). This indicates that the optimized silicon powder particle size distribution and the modified nano-alumina and organosilicon prepolymer of the present invention have better compatibility and synergistic effect, and can more effectively form a dense stacked structure, thereby obtaining the best bonding performance.

[0212] In summary, by optimizing the particle size distribution of silicon powder and introducing modified nano-alumina and organosilicon prepolymers, this invention solves the shortcomings of existing silicon material binders in terms of high-temperature densification, thermal stability, and initial bond strength, and successfully prepares a silicon material binder with better overall performance.

[0213] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.

Claims

1. A silicon material adhesive, characterized in that, The components include the following parts by weight: 100 parts by weight of silicon powder; 3-5 parts by weight of silica sol; 40-60 parts by weight of solvent; 1-3 parts by weight of silane coupling agent; 1-3 parts by weight of thickener; 5-10 parts by weight of modified nano-alumina; 2-5 parts by weight of organosilicon prepolymer; The silicon powder is composed of silicon powder with a particle size of 3-5 μm, silicon powder with a particle size of 15-20 μm, and silicon powder with a particle size of 80-90 μm mixed in a weight ratio of 1:(2-4):(6-8). The modified nano-alumina is nano-alumina surface-treated with silane coupling agent KH-550, and its particle size is 10-30nm; The organosilicon prepolymer is a prepolymer prepared by mixing methyltriethoxysilane and dimethyldiethoxysilane in a molar ratio of 1:(0.8-1.1), and its weight-average molecular weight is 2000-5000.

2. The silicon material binder according to claim 1, characterized in that, The silicon powder is composed of silicon powder with a particle size of 3-5 μm, silicon powder with a particle size of 15-20 μm, and silicon powder with a particle size of 80-90 μm mixed in a weight ratio of 1:3:

7.

3. The silicon material binder according to claim 1, characterized in that, The modified nano-alumina was prepared by the following method: Step 1: Disperse nano-alumina in anhydrous ethanol to form a suspension with a mass concentration of 5-10%; Step 2: Under stirring conditions, add 3-8% by weight of silane coupling agent KH-550 dropwise to the suspension; Step 3: After the addition is complete, reflux the mixture at 60-80°C for 2-4 hours. Step 4: After the reaction is complete, centrifuge, wash the solid product with ethanol 2-3 times, dry it under vacuum at 80-100°C, and grind it to obtain the modified nano alumina.

4. The silicon material binder according to claim 1, characterized in that, The organosilicon prepolymer is a prepolymer prepared by mixing methyltriethoxysilane and dimethyldiethoxysilane in a molar ratio of 1:0.95, and its weight-average molecular weight is 2000-5000.

5. The silicon material binder according to claim 1, characterized in that, The organosilicon prepolymer is prepared by the following method: Step 1: Mix methyltriethoxysilane and dimethyldiethoxysilane in a molar ratio of 1:(0.8-1.2); Step 2: Under stirring conditions, slowly add catalyst equivalent to 1-2% of the total weight of silane and deionized water equivalent to 1.5-2 times the total volume of silane, and carry out hydrolysis-condensation reaction at 50-70°C for 3-5 hours. Step 3: After the reaction is complete, allow the mixture to stand and separate into layers. Remove the lower aqueous phase and wash the upper organic phase with deionized water until neutral. Then, dehydrate the organic silicon prepolymer under reduced pressure for 1-2 hours at 100-120°C and -0.09~-0.1MPa to obtain the organosilicon prepolymer with a weight average molecular weight of 2000-5000.

6. The silicon material binder according to claim 5, characterized in that, The catalyst is hydrochloric acid or p-toluenesulfonic acid.

7. The silicon material binder according to claim 1, characterized in that, The silane coupling agent includes one or more of trimethoxysilane, triethoxysilane, tetramethyl silicate, and tetraethyl silicate.

8. The silicon material binder according to claim 1, characterized in that, The thickener includes one or more of methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, and hydroxypropylmethylcellulose.

9. A method for preparing the silicon material binder according to any one of claims 1-8, characterized in that, Includes the following steps: Step 1: Add the thickener to the solvent according to the specified ratio and mix well to obtain mixture A; Step 2: Mix the silicon powder, silane coupling agent, modified nano-alumina and organosilicon prepolymer evenly according to the formula to obtain mixture B; Step 3: After mixing mixture A and mixture B evenly, add silica sol according to the ratio and mix evenly to obtain the final product.

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