A method for preparing a toughened paste for large-size chip bottom packaging

Abstract

The present application relates to a kind of toughening slurry preparation methods for large size chip bottom package, raw material includes according to weight fraction: modified epoxy resin 50-70 parts, toughening resin 15-25 parts, active diluent 2-5 parts, coupling agent 0.5-1 part, defoaming agent 0.5-1 part, dispersing agent 0.5-1 part.The toughening slurry prepared in the application is good in compatibility with the main body epoxy resin in formula, it is helpful to the dispersion of silicon powder filler, and the toughening effect is better than traditional toughening formula, can be directly applied in the formula design of chip level bottom filling glue, can alleviate or offset the internal stress in the curing and reliability process test process in large size chip packaging.And this slurry can form separate toughening raw material, or be prepared into similar intermediate premix product by this method, can be widely used in other types of epoxy adhesive.

Description

Technical Field

[0001] This invention relates to the preparation of a toughening slurry for bottom packaging of large-size chips, which can be used in the field of thermosetting epoxy electronic adhesive materials. Background Technology

[0002] In chip packaging technology, the bonding layer between the IC chip and the organic substrate consists of numerous tiny solder joints. These joints have poor deformation adaptability and are extremely sensitive to thermal stress, making structural reliability issues more prominent. Using polymer underfill to improve the reliability of packaged chips is a novel method developed in recent years. This method is economical and easy to implement. During chip packaging, the underfill material gradually solidifies in the narrow gap between the IC chip and the organic substrate through thermosetting, protecting the connecting solder joints. It can also effectively mitigate impact loads, improve the packaged chip's resistance to deformation, moisture, and chemical corrosion, and significantly extend the fatigue life of the packaged chip, thus showing great development potential.

[0003] Chip-level underfill adhesives tend to accumulate thermal stress during the curing process. After curing, the entire chip package undergoes rigorous reliability tests, including reflow soldering, thermal cycling, high-temperature storage, and high-temperature and high-humidity conditions. During these tests, the internal stress of the chip-level underfill adhesive continuously accumulates. The stress generated at the diagonal ends of the chip is particularly high, especially with larger chip sizes. Eventually, when the accumulated thermal stress exceeds the material's inherent strength, failure occurs, such as edge separation, underfill cracking, and in severe cases, solder joint breakage or even wafer shattering. To address these issues, toughening and flexibility enhancement must be considered in the formulation design. However, due to the unique characteristics of chip-level underfill materials, the compatibility between raw materials must be extremely high to prevent material separation during the filling process. Therefore, to improve the flexibility of the cured underfill material, offset or weaken the internal stress caused by curing and the rigorous reliability tests, while ensuring good compatibility between the toughening and flexibility enhancement materials and other materials in the formulation, the toughening slurry in this patent achieves this function. Furthermore, this premixed slurry can also be used in other epoxy adhesive systems that require toughening and flexibility. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a toughening slurry for bottom encapsulation of large-size chips and its preparation method. By introducing the toughening slurry of this invention into the chip-level underfill adhesive formulation, a significant toughening effect can be achieved. Simultaneously, it exhibits good compatibility with the matrix resin, does not affect the overall viscosity and flowability, and, depending on the main resin and additives in the toughening slurry, can impart other effects besides toughening.

[0005] The specific technical solution is as follows:

[0006] One objective of this invention is to provide a toughening paste for bottom encapsulation of large-size chips, characterized in that its raw materials comprise, by weight parts:

[0007] 50-70 parts modified epoxy resin, 15-25 parts toughening resin, 2-5 parts reactive diluent, 0.5-1 part coupling agent, 0.5-1 part defoamer, and 0.5-1 part dispersant.

[0008] Furthermore, the modified epoxy resin is one or more of the following: flexible epoxy resin, polyether-type epoxy resin, and core-shell toughened epoxy resin, preferably a combination of flexible epoxy resin and core-shell toughened epoxy resin, wherein the mass ratio of flexible epoxy resin to core-shell toughened epoxy resin is preferably (1-2):1; the flexible epoxy resin is Dow Chemical's DER-732, DER-736, DER-755, XZ92466, XZ92465, Hunan Celway's HQ-3500E, HQ5500, HQ-1200, HQ-1500E, Daicel's PB3600, PB4700, or Korean S... The flexible epoxy resin is a compound of one or more of the SE-4125P from hin-A company; the flexible epoxy resin generally contains ether bonds in its molecular structure, or contains polypropylene glycol type epoxy, or the polymer structural unit contains double bond structure, etc. Epoxy resins containing the above forms will give conventional epoxy resin structures good flexibility, and can effectively offset the internal stress in material curing and reliability from the perspective of polymer structure design; core-shell toughening epoxy resin generally combines rubber microparticles or core-shell toughening particles with conventional epoxy resin in the form of in-situ polymerization and blending bonding, which can increase the toughness of the material body and prevent the deterioration and propagation of microcracks inside the material.

[0009] Furthermore, the toughening powdered resin is one or more of the following: ethylene-vinyl acetate copolymer (EVA), epoxy-modified silicone elastomer powder, butadiene-styrene-polymethyl methacrylate copolymer (MBS), and styrene-butadiene rubber powder. Preferably, EVA, MBS, and epoxy-modified silicone elastomer powder are used in a synergistic compound, wherein the mass ratio of the three is preferably (1-2):(1-2):1. The toughening epoxy resin can be one or more of the following: Kaneka Corporation's MX-125, MX-136, MX-139, MX-267, and MX-553; Huntsman Corporation's XU3508, LT1522, and Tactix®695; Hunan Cellway's HQ-2000 and HQ3600; and Arkema Corporation's XT-100. The EVA resin is one or more of Arkema's 42-60, 40-55, 33-45PV, 33-400, 33-25, and 28-150; the MBS resin is Arkema's E920 and D480, and Kaneka's M521, M701, M711, M722, and M732; the specific epoxy-modified silicone elastomer can be one or more of Dow Corning's EP2601 and EP2720.

[0010] The EVA resin is a copolymer resin. The higher the vinyl acetate (VA) content, the higher the material's flexibility and impact resistance. It also maintains good flexibility at -50℃ and has good compatibility with inorganic fillers. The MBS resin is also a copolymer resin with a typical core-shell structure, which can provide good toughness at low temperatures. The epoxy-modified silicone elastomers mentioned above have good compatibility with epoxy resin, and because they contain silicon bonds, they can help the material counteract internal stress at high temperatures, thus providing toughening and protection.

[0011] The preparation method of the toughening slurry for bottom filling adhesive of large-size chips includes the following steps: Modified epoxy resin, toughening resin, reactive diluent, coupling agent, defoamer, and dispersant are mixed and stirred in a double planetary mixer at 500-1000 r / min for 1-2 hours. Then, the toughening resin is added, and the temperature inside the mixer is controlled at 80-100℃, while simultaneously dispersing and stirring at high speed at 1500-2000 r / min for 1-2 hours. The preliminary premix is ​​then removed and subjected to variable-gap heating and grinding 5-10 times using a three-roll mill, with the temperature of the three rollers controlled at 80-100℃. The premix after passing through the rollers is then poured back into the mixer, and the temperature inside the mixer is maintained at 80-100℃, while simultaneously dispersing and stirring at high speed at 1500-2000 r / min for 1-2 hours. Finally, the toughening slurry (DBZR) is obtained.

[0012] A second objective of this invention is to provide a method for preparing the chip underfill adhesive containing the toughening slurry (DBZR), which includes the following steps:

[0013] Epoxy resin, toughening slurry (DBZR), coupling agent, defoamer, and black paste are mixed and stirred in a double planetary mixer at a speed of 500-1000 r / min, with the mixer temperature controlled at 80-100℃. After stirring for 1-2 hours, various spherical silica particles are added, and stirring is continued for 1-2 hours under the same temperature control. The premixed material is then removed, milled in multiple stages using a three-roll mill, and then poured back into the mixer. It is stirred at 80-100℃ for 1-2 hours. Subsequently, it is cooled to room temperature, a curing agent is added, and the temperature is maintained at 25-30℃ while stirring for 1-2 hours to obtain the chip bottom filler containing toughening slurry (DBZR).

[0014] Furthermore, the entire preparation process is carried out under vacuum conditions, preferably maintaining a vacuum level of not less than -0.08 MPa throughout the process.

[0015] The epoxy resin is a bisphenol A type epoxy resin or / and a bisphenol F type epoxy resin; specifically, it is one or more of the following: Dow Chemical's DER331J, DER332, DER351, DER353, and DER354; DIC Japan's 830CRP, 830LVP, 835LV, and 850CRP; Huntsman Corporation's GY-281, GY-282, GY-285, and PY302-2; Shin-A Korea's SE-187M, SE-187PM, SEF-170P, SEF-170PM, and SE-55F; and KF-8110 and KF-8120 from KLOON Korea. The above resins are mainly bisphenol A type epoxy resin, bisphenol F type epoxy resin, or a blend of the two, which are the main resins of the entire adhesive and act as a skeleton. Bisphenol A type epoxy resin has high strength but high viscosity, while bisphenol F type epoxy resin has low viscosity but low strength. The combination of the two makes the system have high strength while maintaining a suitable viscosity range.

[0016] The coupling agent is one or more of γ-aminopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-aminopropyltrimethoxysilane; preferably KH560 from Hubei Xinlantian.

[0017] The spherical silica is one or more of the following models from Yatoma Japan: FE920ASQ, FEB25G-SED, SC220G-SQ, SE6050, SE6050-STE, SO-E2, and SO-E2 / 24C.

[0018] The defoamer is one or more of the following: BYK Chemical's 1788, 1790, 1799, and A-535; Zhanxin's PC-1344; and Momentive's TSA750SH; preferably BYK Chemical's 1799.

[0019] The modified amine curing agent is one or more of 4,4'-diamino-3,3'-diethyldiphenylmethane, diethyltoluenediamine, diaminodiphenyl sulfone, m-aminomethylamine, phenylenediamine trimer, dibenzylamino ether, and diethyltoluenediamine; preferably Huntsman's Aradur 5200.

[0020] The beneficial effects of this invention are: introducing the self-prepared toughening slurry into the formulation of chip-level underfill materials can significantly reduce the internal stress generated in the underfill material during curing and reliability testing, thereby toughening the material as a whole and preventing potential cracks from further deteriorating and propagating. A novel and unique aspect of this patent is that the self-prepared toughening slurry can not only be used in the formulation of this patent, but its preparation process can also be combined with other formulation designs for toughening other types of epoxy adhesives.

[0021] Conventional chip-level underfill materials, after curing, show a K1C value of less than 3 MPa. 1 / 2 The DMA test showed a high-temperature elongation at break of less than 10%, while the K1C of the toughening slurry formulation in this patent can reach up to 4 MPa. 1 / 2 The above-mentioned high-temperature elongation at break can exceed 15%. If toughening resin is directly added to conventional chip-level underfill materials, the viscosity will increase significantly, the simulated flow rate will slow down noticeably, resulting in mediocre toughening effect and negatively impacting flow properties due to poor compatibility or dispersibility. However, after toughening with the toughening slurry in this patent, the viscosity increase is minimal while maintaining the above-mentioned toughening properties, and the flow properties are essentially the same as those of conventional chip-level underfill materials. Detailed Implementation

[0022] The principles and features of the present invention are described below. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0023] In each embodiment, the toughening slurry for the chip-level underfill adhesive is prepared by the following method:

[0024] Modified epoxy resin, toughening powdered resin, reactive diluent, coupling agent, defoamer, and dispersant are mixed and stirred in a double planetary mixer at 500-1000 rpm for 1-2 hours. Then, toughening core-shell powder and spherical silica are added. The temperature inside the mixer is controlled at 80-100℃, and the mixture is dispersed and stirred at high speed at 1500-2000 rpm for 1-2 hours. The premixed material is then removed and subjected to variable-gap heating and grinding 5-10 times using a three-roll mill, with the temperature of the three rollers controlled at 80-100℃. The premixed material after passing through the rollers is then poured back into the mixer, and the temperature inside the mixer is controlled at 80-100℃, while the mixture is dispersed and stirred at high speed at 1500-2000 rpm for 1-2 hours. Finally, the toughened slurry (DBZR) is obtained.

[0025] Furthermore, to verify the toughening effect of DBZR in each embodiment, DBZR-01, DBZR-02, DBZR-03, DBZR-04, and DBZR-05 were prepared respectively. The formulation amounts are shown in the table below:

[0026] Table 1. Formulation for preparing toughening slurry DBZR

[0027] DBZR-01 DBZR-02 DBZR-03 DBZR-04 DBZR-05 DER-755 38 38 64 - 38 MX-136 26 26 - 64 26 42-60 15 - 10 10 10 M711 15 15 10 10 10 EP2601 - 15 10 10 10 DER-321 5 5 5 5 5 KH560 0.5 0.5 0.5 0.5 0.5 1799 0.2 0.2 0.2 0.2 0.2

[0028] The preparation method of the chip underfill adhesive containing toughening slurry (DBZR) in the various embodiments and comparative examples includes the following steps:

[0029] Epoxy resin, toughening slurry (DBZR), coupling agent, defoamer, and black paste are mixed and stirred in a double planetary mixer at a speed of 500-1000 r / min, with the mixer temperature controlled at 80-100℃. After stirring for 1-2 hours, various spherical silica particles are added, and stirring continues for 1-2 hours under the same temperature control. The premixed material is then removed, milled in multiple stages using a three-roll mill, and returned to the mixer. It is then stirred at 80-100℃ for 1-2 hours. Subsequently, after the mixer temperature drops to room temperature, a curing agent is added, and the temperature is maintained at 25-30℃. After stirring for 1-2 hours, a chip bottom filler containing toughening slurry (DBZR) is obtained. The entire process maintains a vacuum degree of no less than -0.08 MPa.

[0030] Based on the above preparation process, the specific embodiments and comparative formulations are shown in Table 2 below:

[0031] Table 2. Preparation formulations for examples and comparative examples

[0032] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Comparative Example 1 Comparative Example 2 DER-332 12 12 12 12 12 10 15 12 DER-353 8 8 8 8 8 7 10 8 DBZR-01 5 - - - - - - - DBZR-02 - 5 - - - - - - DBZR-03 - - 5 - - - - - DBZR-04 - - - 5 - - - - DBZR-05 - - - - 5 8 - - 42-60 - - - - - - - 5 KH560 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 1799 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 Homemade black paste 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 SE6050-STE 48 48 48 48 48 48 48 48 SO-E2 / 24C 14 14 14 14 14 14 14 14 5200 12 12 12 12 12 12 12 12

[0033] test

[0034] The room temperature viscosity, viscosity at 110°C, and simulated flow rate of the products obtained in Examples 1-6 and Comparative Examples 1 and 2 are shown in Table 1; the test results of K1C, fracture stress, and strain after curing are shown in Table 2.

[0035] Viscosity test: A Haake viscometer (Thermofisher, USA), C20 / 2 rotor, was used to measure viscosity at room temperature for 20 seconds. -1 Viscosity at 60 s; using a TA rheometer with a disposable plate, heated to 110℃, measured for 60 s. -1 Viscosity at rotational speed.

[0036] Simulated flow rate measurement method: A 20mm*21mm bare silicon wafer was fixed to a glass slide using epoxy structural adhesive with 50μm spacer spheres; this is the simulated sample. The simulated sample was placed on a 110℃ heating platform and allowed to stand for 10 minutes. Then, using a pneumatic pump, underfill adhesive was applied to one end of the silicon wafer in the simulated sample through a nozzle. Timing began immediately after the first application of adhesive. Careful observation was performed, and timing ended when the adhesive had flowed to the opposite edge. This time was recorded as t, the length of the flowing edge was recorded as L, and the final flow rate was recorded as L / t.

[0037] K1C Testing Method and Procedure: Prepare a 65mm*10mm*5mm specimen by curing and smoothing it. Cut a 3-5mm deep and 0.3mm wide notch in the center and place it in the testing environment for at least 12 hours to stabilize. Test the K1C using a universal tensile testing machine. Select the K1C testing program, with the notch facing down, and press downwards at a speed of 10mm / min. The program will directly calculate the K1C value at the moment of fracture.

[0038] Fracture stress and strain testing methods and procedures: A 20mm*5mm*0.3mm specimen was prepared by curing and smoothing, then placed in the testing environment for at least 12 hours to stabilize. Testing was performed using a dynamic thermomechanical analyzer from TA Instruments, selecting the tensile control force mode. The temperature was increased to the target temperature (150℃ and 245℃) at a rate of 3℃ / min. After stabilizing at the target temperature for 1 minute, a tensile force of 5N / min was applied, increasing from an initial 0.01N to 18N. The program automatically stopped when the specimen broke or the tensile force reached 18N, recording the stress and strain changes throughout the process.

[0039] Curing process: In the above sample preparation, the adhesive and mold are first placed in a forced-air oven and heated from room temperature to 165°C at a rate of 5°C / min. The temperature is maintained at 165°C for 2 hours and then naturally cooled to room temperature, at which point curing is complete.

[0040] Table 1. Viscosity and simulated flow rate test results at room temperature and 110℃

[0041] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Comparative Example 1 Comparative Example 2 Viscosity at room temperature (Pa·s) 30.7 27.5 24.9 36.6 28.1 33.3 22.5 56.3 Viscosity at 110℃ (mPa·s) 80.9 74.8 67.2 99.7 81.7 88.6 66.9 145.1 Simulated flow velocity (mm / min) 31.2 34.1 36.3 27.2 35.4 29.8 39.6 14.5

[0042] Table 2 K1C and stress-strain test results

[0043] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Comparative Example 1 Comparative Example 2 <![CDATA[K1C(Mpam 1 / 2 )]]> 3.08 3.52 3.29 4.42 4.01 4.38 1.52 2.03 Strain (%) (245℃) 12.26 11.08 11.73 10.41 17.1 14.83 5.37 8.22 Stress (N) (245℃) 16.71 13.1 17.94 15.37 17.94 17.95 9.21 14.36

[0044] As shown in Table 1, compared with Comparative Examples 1 and 2, directly adding toughening resin to conventional chip-level bottom filler materials in Examples 1-6 significantly increases viscosity and slows down simulated flow rate. This not only results in mediocre toughening effect but also poor compatibility or dispersibility, negatively impacting flow performance. In contrast, the toughening slurry in this patent, after toughening, exhibits a smaller increase in viscosity and better flow performance while maintaining the aforementioned toughening properties.

[0045] As shown in Table 2, K1C characterizes the notch toughness of the cured underfill material, which can reflect the material's resistance to crack initiation and propagation to a certain extent at the macroscopic level. High-temperature fracture tensile stress-strain can characterize the tensile toughness of a material at a specific high temperature, providing guidance for materials undergoing high-temperature reliability testing. Comparative Example 1 shows that when there are no toughening components in the formulation, the K1C value is low, and the tensile toughness is also poor. Such a material, when used in large-size chip packaging, will struggle to offset the internal stress generated during curing and reliability testing, ultimately leading to a high probability of failure such as bulk cracking or interface separation. In Comparative Example 2, the direct addition of 42-60 toughening resin increased the K1C value and improved the tensile toughness, but it remained at a low level.

[0046] Examples 1, 2, and 5 demonstrate that the simultaneous introduction of toughening resins 42-60, M711, and EP2601 into the toughening slurry, with their synergistic effect, improves both the K1C toughness and tensile toughness of the material. It should be noted that the K1C and high-temperature fracture tensile strain characterized in this patent are not absolutely linearly related, as K1C represents room-temperature toughness, while high-temperature fracture tensile strain represents high-temperature toughness. High-temperature toughness is related not only to the toughening mechanism but also to the compatibility of the components within the material. Examples 3, 4, and 5 show that in addition to the toughening resins, the flexible epoxy resin and toughening epoxy resin serving as the matrix resin are also crucial in the toughening slurry. When flexible epoxy is used alone as the matrix resin, the toughening components in the toughening slurry are "diluted" to some extent, resulting in a decrease in K1C toughness but an increase in tensile toughness. This is because flexible epoxy resins typically have longer chain segments and better flexibility. When toughening epoxy is used alone as the matrix resin, K1C toughness can be relatively improved, but tensile toughness is reduced. This is because excessive toughening epoxy can cause the internal toughened core-shell structure to become stress concentration points that lead to fracture under tension. As can be seen from Examples 5 and 6, increasing the amount of toughening slurry (DBZR-05) can increase K1C toughness, but tensile toughness is reduced. This is because the toughening slurry may have exceeded the critical point, causing an imbalance in the overall toughening system. K1C and stress-strain properties are only a means of characterizing macroscopic toughness. The internal situation of specific chip packaging is more complex, and ensuring packaging reliability is the result of the combined effect of multiple properties.

[0047] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A toughened paste for large die bottom encapsulation, characterized by, Its raw materials according to weight fraction includes: modified epoxy resin 50-70 parts, toughening resin 15-25 parts, active diluent 2-5 parts, coupling agent 0.5-1 part, defoaming agent 0.5-1 part, dispersing agent 0.5-1 part; The modified epoxy resin is a combination of flexible epoxy resin and core-shell toughening epoxy resin, and the flexible epoxy resin is one or more of the following: DER-732, DER-736, DER-755, XZ92466, XZ92465 of Dow Chemical, HQ-3500E, HQ5500, HQ-1200, HQ-1500E of Hunan Sailve, PB3600, PB4700 of Japan DKS, and SE-4125P of South Korea Shin-A company; and the core-shell toughening epoxy resin is one or more of the following: MX-125, MX-136, MX-139, MX-267, MX-553 of Japan Tokai, XU3508, LT1522, Tactix®695 of Huntsman, HQ-2000, HQ3600 of Hunan Sailve, and XT-100 of Akema. The toughening resin is a synergistic combination of ethylene-vinyl acetate copolymer EVA, butadiene-styrene-poly (methyl methacrylate) copolymer MBS, and epoxy modified silicone elastomer powder, and the mass ratio of the three is (1-2):(1-2):1; the modified silicone elastomer powder is EP2601 and EP2720 of Dow Corning.

2. The toughened paste for large chip bottom packaging according to claim 1, wherein The toughening resin, specifically the MBS resin, is M521, M701, M711, M722, and M732 of Japan Tokai, and the EVA resin is 42-60, 40-55, 33-45PV, 33-400, 33-25, and 28-150 of Akema.

3. The toughened paste for large chip bottom packaging according to claim 1, wherein the paste is characterized by The active diluent is a combination of one or more of DER-732, DER-736, DER-321, DER-324 of Dow Chemical, and GE-30, GE-31, and GE-40 of CVC.

4. The toughened paste for large die bottom package according to claim 1, wherein The coupling agent is a combination of one or more of γ-aminopropyl triethoxysilane, γ-mercaptopropyl trimethoxysilane, γ-mercaptopropyl triethoxysilane, γ-glycidyl ether propyl trimethoxysilane, and γ-aminopropyl trimethoxysilane; the defoaming agent is a combination of one or more of 1788, 1790, 1799, and A-535 of BYK, PC-1344 of Zhennew, and TSA750SH of Momentive; and the dispersing agent is a combination of one or more of W985, W996, W9010, and 2013 of BYK, SIM-768E of Momentive, DM626 and DM646 of Shenghua Chemical, and AC1210 and AC1215 of Jiangsu Hai'an Petrochemical.

5. A toughened paste for large die bottom packaging according to any one of claims 1 to 3, wherein The preparation method comprises the following steps: blending the modified epoxy resin, active diluent, coupling agent, defoaming agent and dispersant, adding the toughening resin after conventional stirring for 1-2 h, heating at 80-100 ℃, and simultaneously stirring at a high speed of 1500-2000 r / min for 1-2 h, then performing variable-gap heating grinding for 5-10 times through a three-roll grinder, and then continuously heating at 80-100 ℃, while stirring at a high speed of 500-1000 r / min for 1-2 h, so that the toughening slurry is obtained, and is named as DBZR.

6. A chip underfill adhesive comprising the toughened paste of claim 1, the raw materials of which comprise, by weight fraction: The epoxy resin is 15-25 parts, the toughening slurry DBZR is 15-25 parts, the coupling agent is 0.5-1 part, the defoaming agent is 0.5-1 part, the black paste is 0.5-1 part, the various spherical silica is 55-65 parts, and the amine curing agent is 5-10 parts.

7. The underfill adhesive of claim 6, wherein, The preparation method comprises the following steps: blending the epoxy resin, the toughening slurry DBZR, the coupling agent, the defoaming agent and the black paste, stirring for 1-2 h, adding the various spherical silica, performing multi-stage heating grinding through a three-roll grinder, heating and stirring at 70-90 ℃ for 4-6 h, reducing to normal temperature, adding the amine curing agent, and stirring for 1-2 h while controlling the temperature at 25-30 ℃, so that the chip bottom filling adhesive containing the toughening slurry DBZR is obtained.