Low-moisture-absorption conductive adhesive as well as preparation method and application thereof

Abstract

The invention provides a low-moisture-absorption conductive adhesive as well as a preparation method and application thereof, and the low-moisture-absorption conductive adhesive comprises the following components in parts by weight: 8-16 parts of a non-fluorinated acrylate monomer, 0.05-0.2 part of fluorinated acrylate, 2-5 parts of siloxane bridged bismaleimide, 0.5-2 parts of epoxidized polybutadiene, 0.2-1 part of an initiator and 70-90 parts of silver powder. The non-fluorinated acrylate monomer comprises monofunctional long carbon chain alkyl acrylate and polyfunctional acrylate. The low-moisture-absorption conductive adhesive has the advantages of low moisture absorption rate, excellent bonding performance, heat resistance, humidity and heat resistance stability, precipitation resistance, and realization of the unification of high reliability and excellent operation performance.

Description

Technical Field

[0001] This invention belongs to the field of electronic materials technology, specifically relating to a low moisture absorption conductive adhesive, its preparation method and application, which is particularly suitable for the field of microelectronic packaging in high humidity environments. Background Technology

[0002] With the rapid development of microelectronic devices towards high integration and miniaturization, conductive adhesives, as key packaging materials, face the severe challenge of insufficient reliability in humid and hot environments. Traditional acrylate or epoxy resin-based conductive adhesives contain a large number of polar groups, which easily absorb moisture and expand in humid environments, leading to delamination at the chip-substrate / frame interface and a surge in resistivity, severely restricting the long-term stability of devices. At the same time, existing technologies often introduce bismaleimide (BMI) resin with excessively high rigidity to improve heat resistance. However, its brittleness and poor compatibility with the resin system exacerbate the generation of microcracks under humid and hot cycling. While using rubber toughening agents can alleviate stress, the introduction of polar groups leads to an increase in moisture absorption.

[0003] Existing improvement solutions often focus on optimizing a single performance characteristic, making it difficult to systematically overcome technical bottlenecks. For example, when using epoxy-acrylate copolymers to reduce moisture absorption, insufficient crosslinking density often leads to deterioration of high-temperature mechanical properties; while adding fluorosilane coupling agents improves hydrophobicity, interfacial embrittlement caused by phase separation reduces adhesive strength; hyperbranched acrylates inhibit resin precipitation by reducing surface energy, but excessive curing shrinkage induces interfacial debonding. These solutions often address one aspect while neglecting another, failing to simultaneously meet the comprehensive requirements of low moisture absorption, anti-precipitation, and hygrothermal stability.

[0004] Therefore, developing a conductive adhesive with low moisture absorption, excellent damp heat stability, excellent adhesion, heat resistance, and anti-exudation properties is an urgent problem to be solved in this field. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a low-moisture-absorbing conductive adhesive, its preparation method, and its applications. The low-moisture-absorbing conductive adhesive combines low moisture absorption, excellent adhesion, heat resistance, and hygrothermal stability, and is resistant to exudation, achieving a balance between high reliability and excellent workability.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a low-hygroscopic conductive adhesive, wherein, by weight, the low-hygroscopic conductive adhesive comprises 8-16 parts of non-fluorinated acrylate monomer, 0.05-0.2 parts of fluorinated acrylate, 2-5 parts of siloxane-bridged bismaleimide, 0.5-2 parts of epoxidized polybutadiene, 0.2-1 parts of initiator and 70-90 parts of silver powder; wherein the non-fluorinated acrylate monomer comprises monofunctional long-chain alkyl acrylate and polyfunctional acrylate.

[0008] In this invention, monofunctional long-chain alkyl acrylates provide hydrophobicity, while polyfunctional acrylates increase crosslinking density. The combination of these two components synergistically enhances their effectiveness in inhibiting water molecule penetration and reducing moisture absorption. Fluorinated acrylates possess low surface energy, preventing resin precipitation and improving interfacial compatibility. Siloxane-bridged bismaleimide (siloxane-bridged BMI) combines the flexibility of siloxane segments with the heat resistance of bismaleimide, thus improving thermal stability. Epoxidized polybutadiene is used as a toughening agent to alleviate curing stress, and the epoxy groups... This process enhances adhesion. Furthermore, the double bonds in polybutadiene can participate in free radical reactions to form a stable cross-linked structure, which further reduces moisture absorption. By using acrylate monomers, fluorinated acrylates, siloxane-bridged bismaleimide, epoxidized polybutadiene, and silver powder in specific proportions, the resulting conductive adhesive exhibits low moisture absorption, excellent adhesion, heat resistance, and hygrothermal stability, as well as resistance to exudation. This makes the conductive adhesive suitable for microelectronic packaging in high-humidity environments, achieving a balance between high reliability and excellent operational performance.

[0009] In this invention, 8 to 16 parts of non-fluorinated acrylate monomer, for example, can be 9 parts, 9.5 parts, 10 parts, 10.5 parts, 11 parts, 11.5 parts, 12 parts, 12.5 parts, 13 parts, 13.5 parts, 14 parts, 14.5 parts, 15 parts, 15.5 parts, 15.8 parts, etc.

[0010] In this invention, 0.05 to 0.2 parts of fluoroacrylate can be, for example, 0.06 parts, 0.07 parts, 0.08 parts, 0.09 parts, 0.1 parts, 0.11 parts, 0.12 parts, 0.13 parts, 0.14 parts, 0.15 parts, 0.16 parts, 0.17 parts, 0.18 parts, 0.19 parts, etc.

[0011] In this invention, 2 to 5 parts of siloxane-bridged bismaleimide can be, for example, 2.2 parts, 2.4 parts, 2.6 parts, 2.8 parts, 3 parts, 3.2 parts, 3.4 parts, 3.6 parts, 3.8 parts, 4 parts, 4.2 parts, 4.4 parts, 4.6 parts, 4.8 parts, etc.

[0012] In this invention, if the content of the siloxane-bridged bismaleimide is too low, the thrust will decrease at high temperatures and the thermal stability will be poor; if the content is too high, the relative content of the low-hygroscopic acrylate will decrease, which will lead to a decrease in thrust at both room temperature and high temperature, and a deterioration in resistance to humid heat.

[0013] In this invention, 0.5 to 2 parts of epoxidized polybutadiene can be, for example, 0.6 parts, 0.8 parts, 1 part, 1.2 parts, 1.4 parts, 1.6 parts, 1.8 parts, 1.9 parts, etc.

[0014] In this invention, if the content of the epoxidized polybutadiene is too low, the thrust at normal high temperature will be reduced, the resistance to damp heat will be poor, and the moisture absorption rate will be high; if the content is too high, it will damage the bulk strength and cross-linking density of the cured adhesive, resulting in a loose molecular structure, which will also lead to an increase in moisture absorption rate, a decrease in thrust at normal high temperature, and poor resistance to damp heat.

[0015] In this invention, 0.2 to 1 part of initiator can be, for example, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, etc.

[0016] In this invention, 70 to 90 parts of silver powder can be, for example, 72 parts, 74 parts, 76 parts, 78 parts, 80 parts, 82 parts, 84 parts, 86 parts, 88 parts, etc.

[0017] In this invention, the total mass of all components of the low-hygroscopic conductive adhesive is 100 parts.

[0018] In this invention, the non-fluorinated acrylate monomer refers to an acrylate monomer that does not contain fluorine atoms.

[0019] Preferably, the mass ratio of the monofunctional long-chain alkyl acrylate to the polyfunctional acrylate is 1:(3~6), wherein the specific values ​​of (3~6) can be, for example, 3.2, 3.4, 3.6, 3.8, 4, 4.2, 4.4, 4.6, 4.8, 5, 5.2, 5.4, 5.6, 5.8, etc.

[0020] In this invention, the high proportion of polyfunctional acrylates and excessive crosslinking density lead to excessive shrinkage and internal stress, resulting in poor adhesion, heat resistance, moisture absorption, and hygrothermal stability of the conductive adhesive. Monofunctional long-chain alkyl acrylates can appropriately reduce the crosslinking density and alleviate internal stress; however, an excessively high proportion of monofunctional long-chain alkyl acrylates is also not conducive to maintaining good adhesion properties.

[0021] Preferably, the long-chain alkyl acrylate in the monofunctional long-chain alkyl acrylate has ≥10 carbon atoms, for example, 12, 14, 16, 18, 20, etc.

[0022] Preferably, the monofunctional long-chain alkyl acrylate includes at least one of hexadecyl acrylate, octadecyl acrylate, lauryl acrylate, and lauryl methacrylate.

[0023] Preferably, the multifunctional acrylate includes at least one of bisphenol A diacrylate, tricyclodecanediethanol diacrylate, and ethylene glycol dicyclopentenyl ether methacrylate.

[0024] In this invention, the multifunctional acrylate preferably comprises a combination of bisphenol A diacrylate oxyacetylene oxide, tricyclodecanediethanol diacrylate, and ethylene glycol dicyclopentenyl ether methacrylate; the mass ratio of the bisphenol A diacrylate oxyacetylene oxide, tricyclodecanediethanol diacrylate, and ethylene glycol dicyclopentenyl ether methacrylate is (2.5~3.5):(7.5~8.5):(1.5~2.5); wherein, in (2.5~3.5) Specific values ​​can be, for example, 2.6, 2.7, 2.8, 2.9, 3, 3.1, 3.2, 3.3, 3.4, etc.; specific values ​​in (7.5~8.5) can be, for example, 7.6, 7.7, 7.8, 7.9, 8, 8.1, 8.2, 8.3, 8.4, etc.; specific values ​​in (1.5~2.5) can be, for example, 1.6, 1.7, 1.8, 1.9, 2, 2.2, 2.2, 2.3, 2.4, etc.

[0025] Preferably, the fluoroacrylate includes at least one of hexafluorobutyl acrylate, trifluoroethyl acrylate, trifluoroethyl methacrylate, and perfluorooctyl ethyl acrylate.

[0026] Preferably, the general structural formula of the siloxane-bridged bismaleimide is as follows: ; wherein R1 and R2 are each independently selected from bismaleimide groups containing a diphenylmethane structure; R, Each is independently selected from straight-chain or branched alkyl groups of C1 to C6 (e.g., methyl, ethyl, n-propyl, etc.), and n is selected from an integer of 4 to 6, for example, 5.

[0027] Preferably, the viscosity of the epoxidized polybutadiene at 45°C is 10,000~35,000 cps, for example, it can be 12,000 cps, 15,000 cps, 18,000 cps, 20,000 cps, 22,000 cps, 25,000 cps, 28,000 cps, 30,000 cps, 32,000 cps, 34,000 cps, etc.

[0028] Preferably, the initiator comprises a peroxide initiator.

[0029] In this invention, the peroxide initiator includes, but is not limited to, cumene hydroperoxide.

[0030] Preferably, the silver powder includes spherical silver powder and / or flake silver powder; more preferably, a combination of spherical silver powder and flake silver powder can significantly improve the thermal conductivity of the chip conductive adhesive.

[0031] In this invention, there are no special restrictions on the source of the silver powder; commercially available products well known to those skilled in the art can be used, such as Metalor's SA0201, TECHNIC Inc.'s SF-125, and Toyo Chemical's KT071.

[0032] In a second aspect, the present invention provides a method for preparing the low-moisture-absorbing conductive adhesive described in the first aspect, the method comprising the following steps:

[0033] The low-hygroscopic conductive adhesive is obtained by mixing non-fluorinated acrylate monomers, fluorinated acrylates, siloxane-bridged bismaleimide, epoxidized polybutadiene, initiator and silver powder.

[0034] Preferably, the mixing method includes: premixing non-fluorinated acrylate monomers, fluorinated acrylates, siloxane-bridged bismaleimide, epoxidized polybutadiene and an initiator, grinding to obtain a homogeneous mother liquor; mixing the homogeneous mother liquor with silver powder, degassing to obtain the low-hygroscopic conductive adhesive.

[0035] Preferably, the grinding is performed in a three-roll mill.

[0036] Preferably, the grinding process is performed ≥3 times, for example, 4 times, 5 times, 6 times, 7 times, 8 times, 9 times, 10 times, etc.

[0037] Preferably, the degassing vacuum degree is ≤-0.095 MPa, and the time is 15~25 min, for example, 16 min, 18 min, 20 min, 22 min, 24 min, etc.

[0038] In this invention, the preparation method of the low moisture absorption conductive adhesive is simple, the conditions are mild and easy to control, and it has good process adaptability.

[0039] Thirdly, the present invention provides an application of the low moisture absorption conductive adhesive as described in the first aspect in chip mounting.

[0040] The numerical range described in this invention includes not only the point values ​​listed above, but also any point values ​​within the numerical ranges not listed above. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific point values ​​included in the range.

[0041] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0042] The low-moisture-absorbing conductive adhesive provided by this invention uses non-fluorinated acrylate monomers, fluorinated acrylates, siloxane-bridged bismaleimide, epoxidized polybutadiene, and silver powder in specific proportions to create a conductive adhesive that combines low moisture absorption, excellent adhesion, heat resistance, and hygrothermal stability with anti-exudation properties. This makes the conductive adhesive suitable for microelectronic packaging in high-humidity environments, achieving a balance between high reliability and excellent operational performance. Detailed Implementation

[0043] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0044] All materials used in this invention can be purchased commercially or prepared using conventional methods. Unless otherwise specified, the materials used in this invention are shown in Table 1.

[0045] Table 1

[0046]

[0047] BMI-PPG1000: In-house prepared, the specific preparation method includes: dissolving 253.5g of maleimide propionic acid in 2500mL of dichloromethane to obtain solution A; dissolving 309g of dicyclohexylcarbodiimide in 300mL of dichloromethane to obtain solution B; adding solution B dropwise to solution A under stirring; after the addition is complete, stirring is continued for 10min; 500g of PPG-1000 (polypropylene glycol) is added; then 6.1g of 4-dimethylaminopyridine is added; the reaction is stopped after 8h; after filtration, extraction, and drying, the filtrate is evaporated to dryness; after standing and cooling, a solid precipitates out, which is the BMI-PPG1000.

[0048] Examples 1-12, Comparative Examples 1-6

[0049] Examples 1-12 and Comparative Examples 1-6 each provide a low-moisture-absorbing conductive adhesive. The formulations of the low-moisture-absorbing conductive adhesives are shown in Tables 2-4 by weight; " / " indicates that the component is not present.

[0050] Unless otherwise specified, the preparation method of the low moisture absorption conductive adhesive of the present invention includes:

[0051] (1) Non-fluorinated acrylate monomers, fluorinated acrylates, siloxane-bridged BMI, epoxidized polybutadiene and peroxide initiator were dispersed at high speed and then milled three times with a three-roll mill to form a stable homogeneous mother liquor.

[0052] (2) The homogeneous mother liquor is mixed with silver powder, passed through three rollers and degassed for 15 minutes under vacuum degree ≤ -0.095 MPa to obtain the low moisture absorption conductive adhesive.

[0053] Table 2

[0054]

[0055] Table 3

[0056]

[0057] Table 4

[0058]

[0059] Comparative Example 7

[0060] This comparative example provides a low-hygroscopic conductive adhesive, which differs from Example 1 only in that 3 parts of siloxane-bridged BMI are replaced with a mixture of 2.5 parts of 4,4'-diphenylmethane bismaleimide and 0.5 parts of γ-glycidyl etheroxypropyltrimethoxysilane. The other components, amounts, and preparation methods are the same as in Example 1.

[0061] Comparative Example 8

[0062] This comparative example provides a low-hygroscopic conductive adhesive, which differs from Example 1 only in that 3 parts of siloxane BMI are replaced with 3 parts of BMI-PPG1000. All other components, dosages, and preparation methods are the same as in Example 1.

[0063] Performance testing

[0064] The following performance tests were performed on the low-moisture-absorbing conductive adhesives provided in the examples and comparative examples.

[0065] (1) Die-Shear Strength: The die-shear strength test method refers to "HG / T 5912-2021 Conductive Adhesives". The silicon wafer size is 2mm×2mm; the substrate is silver-plated copper sheet; the curing conditions are 175℃×1.0h in a forced-air oven; the test equipment is a DAGE-4000P multi-functional push-pull tester, Nordson DAGE Precision Industries LTD, USA. The shear strength is the magnitude of the push force (unit is kgF); 10 samples of each adhesive are taken, and the average value is taken. When measuring the high-temperature push force at 260℃, the temperature control heating platform is set to the desired temperature and stabilized for 5 minutes after reaching the target temperature. The push force is then measured according to the aforementioned method.

[0066] (2) Moisture absorption rate: According to the national standard GB / T35494.1-2017, three cured adhesive samples with dimensions of 2 cm×1 cm×60 μm were taken, dried at 110℃ for 2 hours and weighed initially. After being placed in a constant temperature and humidity chamber at 85℃ / 85% RH for 168 hours, they were cooled and weighed. The percentage increase in mass was calculated to obtain the moisture absorption rate, and the arithmetic mean of the three groups was taken.

[0067] (3) Moisture and heat resistance: The chip push silicon wafer was steamed in a PCT aging chamber for 16 h at 121℃ and 2 bar of water vapor, and then the chip push test and residual glue rate were evaluated.

[0068] (4) Evaluation of resin precipitation: After the conductive adhesive applied to the silver-plated copper sheet has cured, it is observed by an optical microscope to measure the size of the resin precipitation (i.e., RBO) around the conductive adhesive.

[0069] The test results are summarized in Table 5; where “ / ” indicates that the conductive adhesive separates after standing, making it impossible to conduct adhesive mixing tests and thus not feasible for application.

[0070] Table 5

[0071]

[0072] The test results show that this invention achieves a balance between moisture absorption, crosslinking density, interfacial compatibility, and hygrothermal stability in conductive adhesives by designing a composite resin of non-fluorinated acrylate monomers and siloxane-bridged BMI, combined with the interface regulation of fluorinated acrylates and the non-polar toughening of epoxidized polybutadiene. Ultimately, it achieves a unified high reliability and moisture sensitivity rating with excellent operational performance. The low moisture absorption conductive adhesive has a chip thrust ≥6.5 kgF at 25°C, a chip thrust ≥1.5 kgF at 260°C, a moisture absorption ≤0.14%, and a chip thrust ≥4.2 kgF after PCT aging, with virtually no resin precipitation.

[0073] Compared with Example 1, Example 5 shows that by increasing the content of siloxane-bridged BMI, the high-temperature thrust of the chip is significantly improved and the moisture absorption rate is reduced.

[0074] Compared to Example 1, Example 2 showed a higher proportion of multifunctional acrylates, resulting in a significant decrease in chip thrust at both room and high temperatures, an increase in moisture absorption, and a large decrease in thrust after PCT damp heat aging. This is because a higher proportion of multifunctional acrylates leads to excessive crosslinking density, resulting in excessive shrinkage and internal stress, which is detrimental to the performance balance of the conductive adhesive. Monofunctional long-chain alkyl acrylates, on the other hand, can appropriately reduce crosslinking density and alleviate internal stress.

[0075] Compared with Example 1, Example 3 shows a lower proportion of multifunctional acrylates and a higher proportion of monofunctional long-chain alkyl acrylates. This results in a significant decrease in chip thrust at both room and high temperatures, and an increase in moisture absorption. This is because while monofunctional long-chain alkyl acrylates can appropriately reduce crosslinking density and alleviate internal stress, higher concentrations are not conducive to maintaining good adhesive properties.

[0076] Compared to Example 1, Comparative Example 1, without the addition of siloxane-bridged BMI, resulted in a significant decrease in high-temperature thrust and an increase in moisture absorption under the same material ratio. The thrust reduction after PCT damp heat aging was also substantial. This is because the bismaleimide structure of the siloxane-bridged BMI helps improve high-temperature adhesion, while the siloxane segments have low moisture absorption and stress-relieving properties, thus improving moisture absorption and damp heat resistance.

[0077] Compared to Example 1, Comparative Example 2, without the addition of epoxidized polybutadiene, resulted in a significant decrease in chip thrust at both room temperature and high temperature, an increase in moisture absorption, and a large decrease in thrust after PCT damp heat aging, all under the same material ratio. This is because epoxidized polybutadiene acts as a toughening agent, relieving curing stress. Simultaneously, the epoxy groups enhance adhesion, and the double bonds in polybutadiene can participate in free radical reactions to form a stable cross-linked structure with excellent hydrophobicity.

[0078] Compared with Example 1, Comparative Example 3, without the addition of fluoroacrylate, showed more severe resin precipitation under the same material ratio. This is because fluoroacrylate has low surface energy, which can prevent resin precipitation, improve interfacial compatibility, and the acrylate groups can participate in crosslinking to form a stable polymer structure.

[0079] As can be seen from Example 1 and Comparative Examples 4-6, if the content of fluorinated acrylate, siloxane-bridged bismaleimide, or epoxidized polybutadiene is too high, it will also lead to a deterioration of at least one of the conductive adhesive's bonding performance, heat resistance, and damp heat resistance, and an increase in moisture absorption.

[0080] As can be seen from Example 1 and Comparative Examples 7-8, without the use of siloxane-bridged bismaleimide, conductive adhesive cannot be applied, or at least one of the following properties—adhesion, heat resistance, and resistance to damp heat—deteriorates, and moisture absorption increases.

[0081] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A low-moisture-absorbing conductive adhesive, characterized in that, By weight, the low-moisture-absorbing conductive adhesive comprises 8-16 parts of non-fluorinated acrylate monomer, 0.05-0.2 parts of fluorinated acrylate, 2-5 parts of siloxane-bridged bismaleimide, 0.5-2 parts of epoxidized polybutadiene, 0.2-1 parts of initiator and 70-90 parts of silver powder. The non-fluorinated acrylate monomers include monofunctional long-chain alkyl acrylates and polyfunctional acrylates.

2. The low-moisture-absorbing conductive adhesive according to claim 1, characterized in that, The mass ratio of the monofunctional long-chain alkyl acrylate to the polyfunctional acrylate is 1:(3~6).

3. The low-moisture-absorbing conductive adhesive according to claim 1 or 2, characterized in that, The monofunctional long-chain alkyl acrylate has ≥10 carbon atoms in the long-chain alkyl group; Preferably, the monofunctional long-chain alkyl acrylate includes at least one of hexadecyl acrylate, octadecyl acrylate, lauryl acrylate, and lauryl methacrylate. Preferably, the multifunctional acrylate includes at least one of bisphenol A diacrylate, tricyclodecanediethanol diacrylate, and ethylene glycol dicyclopentenyl ether methacrylate.

4. The low-moisture-absorbing conductive adhesive according to any one of claims 1 to 3, characterized in that, The fluoroacrylates include at least one of hexafluorobutyl acrylate, trifluoroethyl acrylate, trifluoroethyl methacrylate, and perfluorooctyl ethyl acrylate; Preferably, the general structural formula of the siloxane-bridged bismaleimide is as follows: ; wherein R1 and R2 are each independently selected from bismaleimide groups containing a diphenylmethane structure; R, Each is independently selected from straight-chain or branched alkyl groups of C1 to C6, and n is selected from integers of 4 to 6.

5. The low-moisture-absorbing conductive adhesive according to any one of claims 1 to 4, characterized in that, The viscosity of the epoxidized polybutadiene at 45°C is 10,000~35,000 cps; Preferably, the initiator comprises a peroxide initiator.

6. The low-moisture-absorbing conductive adhesive according to any one of claims 1 to 5, characterized in that, The silver powder includes spherical silver powder and / or flake silver powder.

7. A method for preparing a low-moisture-absorbing conductive adhesive according to any one of claims 1 to 6, characterized in that, The preparation method includes the following steps: The low-hygroscopic conductive adhesive is obtained by mixing non-fluorinated acrylate monomers, fluorinated acrylates, siloxane-bridged bismaleimide, epoxidized polybutadiene, initiator and silver powder.

8. The preparation method according to claim 7, characterized in that, The mixing method includes: premixing non-fluorinated acrylate monomers, fluorinated acrylates, siloxane-bridged bismaleimide, epoxidized polybutadiene and an initiator, grinding them to obtain a homogeneous mother liquor; mixing the homogeneous mother liquor with silver powder, degassing, to obtain the conductive adhesive.

9. The preparation method according to claim 8, characterized in that, The grinding is performed in a three-roll mill. Preferably, the grinding process is performed ≥3 times; Preferably, the degassing vacuum degree is ≤-0.095 MPa, and the time is 15~25 min.

10. The application of a low-moisture-absorbing conductive adhesive as described in any one of claims 1 to 6 in chip mounting.

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