Anti-warping bottom filling adhesive for flip chip packaging and preparation method of anti-warping bottom filling adhesive

Abstract

The invention relates to an anti-warping bottom filling adhesive for flip chip packaging. The anti-warping bottom filling adhesive comprises the following raw materials in parts by mass: 12-17 parts of epoxy resin, 5-8 parts of flexible epoxy resin, 3-6 parts of maleimide resin, 5-10 parts of a curing agent containing more than two amino groups, 0.5-2 parts of a coupling agent and 60-70 parts of coupling agent modified spherical silica powder, the flexible epoxy resin is at least one of organic silicon modified epoxy resin, polyether modified epoxy resin and polyurethane modified epoxy resin; the maleimide resin contains a repeating unit represented by the following formula (I). According to the invention, through reasonable compatibility of the components of the underfill adhesive, especially the self-made maleimide resin, the anti-warping performance of the underfill adhesive is obviously improved; by pretreating the inorganic heat-conducting filler, the surface wettability and heat and humidity resistance of the inorganic powder are improved, so that the underfill adhesive has high filling and high flowability.

Description

Technical Field

[0001] The invention belongs to the technical field of epoxy glue, and in particular relates to a bottom filling glue for flip chip packaging and a preparation method thereof. Background Art

[0002] As an important electronic adhesive for integrated circuit packaging, bottom filler is used in advanced packaging such as 2.5D and 3D packaging to alleviate the stress concentration problem caused by the mismatch of thermal expansion coefficients between different materials in chip packaging, thereby improving the reliability of device packaging. Among them, flip-chip underfill is used to fill the gap between the interconnection bumps of the chip and the packaging substrate, and the accuracy is required to reach the micron level. The bottom filler flows into the gap between the IC chip circuit with conductive bumps and the substrate through capillary action. Mainly used in CPU, LSI and GPU, the bottom filler material for flip-chip packaging has different thermal expansion coefficient (CTE) characteristics between the substrate and the flip chip. When heat treatment (secondary reflow) is performed, the packaged product may warp upward or downward, resulting in poor product reliability. In addition, as chips and substrates become thinner, warpage control becomes more and more important. As electronic packaging tends to be faster, smaller and thinner, it needs to be reduced in size. It is not easy to ensure the flatness and high reliability of the chip. A bottom filler with better performance is needed to effectively control the warping phenomenon. Therefore, the bottom filler needs to have high fluidity and high Tg, as well as a low coefficient of thermal expansion (CTE) and suitable mechanical properties with both rigidity and toughness. Especially at present, the degree of chip integration is getting higher and higher, the size is getting smaller and smaller, and heterogeneous integrated packaging will generate a lot of heat, which puts higher requirements on the anti-warping performance of the bottom filler. In order to improve the anti-warping performance of the bottom filler, the current existing technology mainly reduces the thermal expansion coefficient and often introduces a larger molecular weight, but it will affect the fluidity and drop resistance.

[0003] CN118725797A discloses a chip-level bottom filling glue suitable for 2.5D heterogeneous integrated packaging, comprising the following components: 10-15 parts of self-synthesized silicone epoxy resin A, 35-40 parts of epoxy resin B, 3-6 parts of coupling agent, 2-4 parts of black paste, 55-65 parts of filler, and 25-35 parts of curing agent; the structural formula of the silicone epoxy resin A is as follows:

[0004]

[0005] CN116285881A discloses a paste-like bottom filling adhesive with high thermal conductivity and low thermal expansion coefficient, comprising the following components in parts by weight: 100-120 parts of flexible block copolymer epoxy resin, 5-10 parts of modified amine curing agent, 50-60 parts of carbon fiber powder, 80-120 parts of filler, and 10-20 parts of auxiliary agent; the flexible block copolymer epoxy resin is prepared using bisphenol F epoxy resin and acrylic block copolymer as raw materials and triphenylphosphine as a catalyst.

[0006] CN116042153A discloses a bottom filling adhesive with high temperature, high bonding strength and low thermal expansion coefficient, comprising the following components by mass: 10 to 25 parts of liquid epoxy resin, 50 to 80 parts of spherical silica, 5 to 15 parts of curing agent, 0.1 to 3 parts of coupling agent, 0.1 to 2 parts of auxiliary agent and 0.1 to 10 parts of imidazole derivative; the imidazole derivative has the following structural formula: R1 is one or two of hydrogen, methyl, ethyl, long-chain alkyl, phenyl and biphenyl; R2 is one of hydrogen, halogen, methyl, ethyl, long-chain alkyl and phenyl.

[0007] The prior art has improved the anti-warping performance by adding bismaleimide resin. Japanese patent JP2023121157A discloses a polyimide curing resin for bonding electronic components, using various bismaleimide resins. The bismaleimide resin with the following chemical structure has better anti-warping performance, but is not resistant to high temperatures.

[0008]

[0009] CN103875065A discloses a bottom filling glue, which includes a (meth) acrylic acid compound, isocyanuric acid having an allyl group, and a maleimide compound, wherein a bismaleimide compound having the following structure has a better effect.

[0010]

[0011] The above-mentioned bottom filling glue of the prior art has made some progress in anti-warping, but due to insufficient consideration of mechanical properties, the anti-warping performance at high temperature still cannot meet the requirements. At the same time, other properties of the bottom filling glue, such as fluidity, bonding strength, and reworkability, also need to be taken into account. Summary of the invention

[0012] In order to overcome the problem that the anti-warping performance and other properties of the bottom filling glue used for flip chips in the prior art cannot be taken into account, especially the deterioration of the anti-warping performance at high temperatures, the present invention proposes an anti-warping bottom filling glue with excellent comprehensive performance, including a homemade maleimide resin, which solves the problem that the chip is prone to warping at high temperatures and has excellent mechanical properties and fluidity. Specifically, the present invention proposes the following technical solutions to solve the above problems:

[0013] A bottom filling glue for anti-warping flip chip packaging comprises the following raw materials in parts by mass: 12-17 parts of epoxy resin, 5-8 parts of flexible epoxy resin, 3-6 parts of maleimide resin, 5-10 parts of a curing agent containing more than two amine groups, 0.5-2 parts of a coupling agent, and 60-70 parts of coupling agent-modified spherical silicon powder; the flexible epoxy resin is at least one of an organosilicon-modified epoxy resin, a polyether-modified epoxy resin, and a polyurethane-modified epoxy resin; the maleimide resin contains a repeating unit of the following formula (I):

[0014]

[0015] Furthermore, the number average molecular weight of the maleimide resin is 5000-10000, preferably 6500-8300.

[0016] Furthermore, the maleimide resin has a structure of the following formula (II):

[0017]

[0018] Where n is 8-12.

[0019] The present invention uses the above-mentioned maleimide resin, which can make the bottom filling glue maintain good anti-warping performance under high temperature environment. It has a soft segment of PEG and multiple maleimide groups located in the side chain and the end group, and can react with amines to produce a rich cross-linked structure, while providing heat resistance and toughness, thereby improving the anti-warping property of the substitute filling glue. In the prior art, the bottom filling glue is generally a bismaleimide resin, and the degree of cross-linking is not enough. If a hyperbranched maleimide resin is used, the toughness of the bottom filling glue after curing will be reduced, and the anti-fall performance will be reduced. The maleimide resin used in the present invention has both toughness and high temperature resistance, and significantly improves the anti-warping property of the bottom filling glue under the precursor that ensures that other properties are not adversely affected. Those skilled in the art can clearly recognize that the polymer of the above formula (II) is a structural schematic diagram of the maleimide resin of the present invention. Due to the complexity of the polymer reaction, it may not be possible that the side chains of all structural units contain maleimide groups.

[0020] Furthermore, the maleimide resin is prepared by a preparation method comprising the following steps:

[0021] (S1) 1,5-pentanediisocyanate (PDI) and 1,3-propylene glycol are added in a molar ratio of 2.4-2.6:1 in the presence of an organic bismuth catalyst to prepare an allophanate polymer containing isocyanate in the side chains and the terminal groups;

[0022] (S2) An allophanate polymer and maleimide ethyl alcohol are reacted at a molar ratio of isocyanate group to maleimide group of 1:1.1-1.2 to obtain a maleimide resin having maleimide groups in the side chains and at the end groups.

[0023] Further, in step (S1), the organic bismuth catalyst is bismuth acetate or bismuth isooctanoate, and the amount of the organic bismuth catalyst is 500-1000ppm of the total mass of 1,5-pentanediisocyanate and 1,3-propylene glycol. The molar equivalent ratio of 1,5-pentanediisocyanate to 1,3-propylene glycol is 2:1. In order to obtain NCO-containing side chains as much as possible, 1,5-pentanediisocyanate needs to be excessive, so it is appropriate to feed the material at a molar ratio of 2.4-2.6:1.

[0024] Furthermore, in step (S1), the reaction is carried out under an inert atmosphere at 60-80° C. for 4-6 hours, and the reaction is stopped until the NCO content of the system no longer changes. The product is separated by a short-path thin film evaporator to obtain an allophanate polymer containing isocyanate at the side chain and the end group as an intermediate.

[0025] Furthermore, in step (S2), the reaction conditions are to react in a reactor at 60-80° C. for 2-3 hours to obtain maleimide resin.

[0026] Furthermore, the epoxy resin is at least one of glycidylamine epoxy resin, bisphenol F epoxy resin, hydrogenated bisphenol A, resorcinol epoxy resin, dicyclopentadiene epoxy resin, and biphenyl epoxy resin, and the epoxy value is 0.3-0.5. For example, the glycidylamine epoxy resin is selected from at least one of triglycidyl para-aminophenol, 4,4'-diaminodiphenylmethane tetraglycidylamine epoxy resin, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenyl ether, N,N,N',N'-tetraglycidyl-1,4-diaminobenzene, N,N,N',N'-tetraglycidyl-1,3-diaminobenzene, and isocyanuric acid triglycidylamine; the bisphenol F epoxy resin is selected from JER807 epoxy resin, EPIKOTE At least one of 862 epoxy resin, EPICLON830 epoxy resin, EPICLON830S epoxy resin, EPICLON835 epoxy resin, CYDF-170, GEFR170, NPEF-170, CYDF-180, YDF2001 and YDF2004; resorcinol epoxy resin is at least one of epoxy resin 680 and Denacol EX-201. Biphenyl epoxy resin is at least one of JSR YX4000, JER-YX4000, JER-YX4000K, JER-YX4000H, JER-YL6121HA, Nippon Kayaku NC3000, Japanese DIC brand HP-5000, Jiashengde BPNE3501 and Jiashengde NPTE4000.

[0027] The silicone-modified epoxy resin is selected from at least one of SILIKOPON EF, SILIKOPON ED, ALBIFLEX 246, ALBIFLEX 296 and ALBIFLEX348; the polyether-modified epoxy resin is EP4000 of ADEKA; the polyurethane-modified epoxy resin is selected from at least one of EPU-6, EPU-73B, EPU-133T, SL3411, SL3412 and SL3413.

[0028] Furthermore, the curing agent containing more than two amine groups is selected from at least one of 3,3'-diethyl 4,4'-diaminodiphenylmethane, diethyltoluenediamine, diaminodiphenylmethane, 3,-ethyl-4,4'-diaminodiphenylmethane, 2,4-diamino-3,5-dimethylthiotoluene, hendiamine, trimethylhexanediamine, m-phenylenediamine, and diaminodiphenyl ether.

[0029] Furthermore, the coupling agent is at least one of an epoxy silane coupling agent, an amino silane coupling agent, an alkenyl silane coupling agent, and a urea silane coupling agent; preferably, the epoxy silane coupling agent and the urea silane coupling agent are compounded in a mass ratio of 2-4:1.

[0030] Furthermore, the epoxy silane coupling agent is selected from at least one of γ-glycidyloxypropyl trimethoxysilane, γ-glycidyloxypropyl triethoxysilane, and γ-glycidyloxypropyl methyl diethoxysilane; the amino silane coupling agent is selected from at least one of 3-(phenylamino)propyl trimethoxysilane, NN diethylaminopropyl trimethoxysilane, and γ-aminopropyl triethoxysilane; the urea silane coupling agent is selected from at least one of γ-urea propyl trimethoxysilane and γ-urea propyl triethoxysilane. The inventors have found that the compounding of the above epoxy silane coupling agent and the urea silane coupling agent can further improve the anti-warping performance.

[0031] Furthermore, the coupling agent modified spherical silicon powder D50 is 0.5-0.8μm, and D100≤3μm. The coupling agent modified spherical silicon powder is prepared by a preparation method comprising the following steps: the spherical silicon powder is baked at 100-130°C for 4-6h for standby use, the silane coupling agent and the alcohol are prepared into a ball milling liquid with a mass concentration of 1-3wt%, the alcohol is selected from at least one of ethanol and isopropanol, preferably anhydrous ethanol; the silane coupling agent is an aminosilane coupling agent, specifically selected from at least one of 3-(phenylamino)propyltrimethoxysilane, NN diethylaminopropyltrimethoxysilane, and γ-aminopropyltriethoxysilane. The baked spherical silicon powder and the ball milling liquid are added to a ball mill according to a mass ratio of 10-20:80-90, wet ball milled, and dried to obtain the coupling agent modified spherical silicon powder.

[0032] Optionally, the raw materials of the bottom filling adhesive for anti-warping flip chip packaging of the present invention further include 0.1-5 parts of pigment, such as carbon black.

[0033] The present invention also provides a method for preparing the above-mentioned bottom filling glue for anti-warping flip chip packaging, comprising the following steps: adding epoxy resin, flexible epoxy resin, maleimide resin, and coupling agent into a vacuum double planetary stirring kettle, evacuating, and stirring until uniformly dispersed; releasing the pressure, heating to 50-70°C, adding pretreated spherical silicon micropowder and then stirring evenly to obtain an epoxy resin composite, passing the above-mentioned epoxy resin composite through three rollers and grinding it three times, standing and aging, stirring again, adding a curing agent, stirring evenly, evacuating, and releasing the pressure to obtain a high-reliability bottom filling glue for flip chip packaging.

[0034] Compared with the prior art, the present invention has achieved the following beneficial effects:

[0035] The present invention significantly improves the anti-warping performance of the bottom filling glue by rationally matching the components of the bottom filling glue, especially the homemade maleimide resin, and has no adverse effect on other properties of the glue. By pre-treating the inorganic thermal conductive filler, the surface wettability and moisture and heat resistance of the inorganic powder are improved, so that the bottom filling glue has high filling and high fluidity. The present invention further improves the anti-warping performance of the bottom filling glue by compounding the coupling agent, thereby making the bottom filling glue have good reliability. DETAILED DESCRIPTION

[0036] The technical solution of the present invention is further explained below with reference to specific embodiments.

[0037] Preparation Example 1

[0038] (S1) 1,5-pentanediisocyanate (PDI) and 1,3-propylene glycol were added in a molar ratio of 2.4:1, and a Bi(OAc)3 catalyst of 500 ppm by weight of the total monomer mass was added. The reaction was carried out at 80°C for 4 hours under a nitrogen atmosphere until the NCO content of the system no longer changed, thereby obtaining an allophanate polymer containing isocyanate in the side chains and the end groups. After testing, the NCO content was 10.7%.

[0039] (S2) The allophanate polymer obtained in step (S1) and maleimide ethyl alcohol are reacted in a molar ratio of isocyanate group to maleimide group of 1:1.1, the reaction solution is extracted and dried with ethyl acetate, and then the organic solvent is evaporated to obtain a maleimide resin containing maleimide groups in the side chains and end groups. After testing, the number average molecular weight of the obtained maleimide resin is about 8300.

[0040] Preparation Example 2

[0041] Other conditions were the same as those in Preparation Example 1, except that in step (S1), the amount of catalyst was 400 ppm, and the reaction was carried out at 70° C. for 4 h, and finally a maleimide resin was obtained with a number average molecular weight of 6500.

[0042] Preparation Example 3

[0043] Spherical silica powder (D50 = 0.5 μm, D100 = 3 μm) was baked at 120°C for 4 h for use; 3-(phenylamino)propyltrimethoxysilane coupling agent and anhydrous ethanol were prepared as a ball milling solution in a mass ratio of 98:2; the baked spherical silica powder and the ball milling solution were added to a ball mill in a mass ratio of 10:90, and wet ball milling was performed at a ball milling speed of 500 rpm. After ball milling for 8 h, vacuum drying was performed to obtain coupling agent modified spherical silica powder.

[0044] Example 1

[0045] 15 parts by mass of bisphenol F epoxy resin CYDF-170, 7 parts by mass of flexible epoxy resin SILIKOPON EF, 5 parts by mass of maleimide resin prepared in Preparation Example 1, and 1.5 parts by mass of silane coupling agent (γ-glycidyloxypropyltrimethoxysilane and γ-ureapropyltrimethoxysilane compounded in a mass ratio of 4:1) are added to a vacuum double planetary stirring kettle, evacuated, and stirred until uniformly dispersed; the pressure is released, the temperature is raised to 50°C, 60 parts by mass of coupling agent-modified spherical silicon powder prepared in Preparation Example 3 are added, and the epoxy resin composite is obtained after being stirred evenly. The epoxy resin composite is passed through three rollers and then ground three times. After standing for 24 hours to mature, 8 parts by mass of curing agent 3,3'-diethyl 4,4'-diaminodiphenylmethane are added again, stirred evenly, evacuated, and the pressure is released to obtain a high-reliability bottom filling glue for flip chip packaging.

[0046] Example 2

[0047] 17 parts by weight of biphenyl epoxy resin NC-3000, 8 parts by weight of flexible epoxy resin ALBIFLEX 246, 6 parts by weight of maleimide resin prepared in Preparation Example 1, and 2 parts by weight of silane coupling agent (γ-glycidyloxypropyltrimethoxysilane and γ-ureapropyltrimethoxysilane compounded in a mass ratio of 2:1) were added to a vacuum double planetary stirring kettle, evacuated, and stirred until uniformly dispersed; the pressure was released, the temperature was raised to 50°C, 70 parts by weight of coupling agent-modified spherical silicon powder prepared in Preparation Example 3 were added, and the epoxy resin composite was obtained after uniform stirring. The epoxy resin composite was passed through three rollers and then ground three times. After standing for 24 hours to mature, 8 parts by weight of curing agent 2,4-diamino-3,5-dimethylthiotoluene was added again, stirred evenly, evacuated, and the pressure was released to obtain a high-reliability bottom filling glue for flip chip packaging.

[0048] Example 3

[0049] The other conditions were the same as those in Example 1, except that the silane coupling agent was γ-glycidyloxypropyltrimethoxysilane.

[0050] Example 4

[0051] The other conditions were the same as those in Example 1, except that the silane coupling agent was γ-ureapropyltrimethoxysilane.

[0052] Example 5

[0053] The other conditions are the same as those in Example 1, except that the maleimide resin is prepared in Preparation Example 2.

[0054] Comparative Example 1

[0055] The other conditions were the same as those in Example 1, except that the maleimide resin prepared in Preparation Example 1 was replaced by an equal mass of bismaleimide resin BMI-80.

[0056] Comparative Example 2

[0057] The other conditions were the same as those in Example 1, except that the maleimide resin prepared in Preparation Example 1 was replaced with an equal mass of bis(3-ethyl-5-methyl-4-maleimidophenyl)methane.

[0058] Comparative Example 3

[0059] The other conditions were the same as those in Example 1, except that the curing agent was replaced by 3,3'-diethyl 4,4'-diaminodiphenylmethane with an equal mass of methyltetrahydrophthalic anhydride.

[0060] Application Examples

[0061] The bottom filling glue obtained in the above-mentioned embodiment and comparative example was subjected to the following performance test, and the results are shown in Table 1 below.

[0062] 1. Viscosity test :The viscosity value was tested using a Brookfield rotational viscometer at a temperature of 25°C, a 52# rotor, a gap of 0.2 mm, and a rotation speed of 10 rpm.

[0063] 2. Flow time test :Use two parallel glass plates with a gap of 50um, record the time it takes for the glue to flow to the 40mm position. Preheat the heating platform at 110℃, add 1g of filling glue, and use a stopwatch to record the time required for 40mm. Observe whether there are bubbles in the glue during the flow process.

[0064] 3. Glass transition temperature Tg test :DSC method is used for testing. 10 mg of sample is placed in the equipment. The temperature is increased from 25℃ to 300℃ at a rate of 10℃ / min. The Tg data can be obtained by analyzing the obtained curve.

[0065] 4. Warpage resistance test: Make a test chip for evaluating the prepared bottom filling. First, on the test chip (Si size: 30mm (width) × 40mm (length) × 0.13mm (thickness), an organic resin substrate (substrate size: 180mm (width) × 240mm (length) × 0.4mm (thickness)) for mounting the test chip is placed. After curing for 120 minutes at 0.6MPa and 165°C, the height difference between the center and the end of the chip is measured as the warpage value.

[0066] Table 1 Bottom filling glue performance test

[0067]

[0068] It can be seen from the data in Table 1 that the bottom filling adhesive provided by the present invention has excellent overall performance, and in particular, the addition of the homemade multifunctional maleimide resin significantly improves the anti-warping property of the bottom filling adhesive.

Claims

1. A bottom filler for anti-warping flip chip packaging, characterized in that: The invention comprises the following raw materials in parts by weight: 12-17 parts of epoxy resin, 5-8 parts of flexible epoxy resin, 3-6 parts of maleimide resin, 5-10 parts of curing agent containing more than two amine groups, 0.5-2 parts of coupling agent, and 60-70 parts of coupling agent-modified spherical silicon powder; the flexible epoxy resin is at least one of silicone-modified epoxy resin, polyether-modified epoxy resin, and polyurethane-modified epoxy resin; the maleimide resin contains a repeating unit of the following formula (I):

2. The bottom filling glue according to claim 1, characterized in that: The number average molecular weight of the maleimide resin is 5000-10000, preferably 6500-8300.

3. The bottom filling glue according to claim 1, characterized in that: The maleimide resin has the structure of the following formula (II): Where n is 8-12.

4. The bottom filling glue according to claim 1, characterized in that: The maleimide resin is prepared by a preparation method comprising the following steps: (S1) 1,5-pentanediisocyanate (PDI) and 1,3-propylene glycol are added in a molar ratio of 2.4-2.6:1 in the presence of an organic bismuth catalyst to prepare an allophanate polymer containing isocyanate in the side chains and the terminal groups; (S2) An allophanate polymer and maleimide ethyl alcohol are reacted at a molar ratio of isocyanate group to maleimide group of 1:1.1-1.2 to obtain a maleimide resin having maleimide groups in the side chains and at the end groups.

5. The bottom filling glue according to claim 4, characterized in that: In step (S1), the organic bismuth catalyst is bismuth acetate or bismuth isooctanoate, and the amount of the organic bismuth catalyst is 500-1000 ppm of the total mass of 1,5-pentanediisocyanate and 1,3-propylene glycol; preferably, in step (S1), the reaction is carried out under an inert atmosphere at 60-80° C. for 4-6 hours, and the reaction is stopped until the NCO content of the system no longer changes, and the product is separated by a short-path thin film evaporator to obtain an allophanate polymer containing isocyanate at the side chain and the end group as an intermediate; and / or In step (S2), the reaction conditions are to react in an autoclave at 60-80° C. for 2-3 hours to obtain maleimide resin.

6. The bottom filling glue according to claim 1, characterized in that: The epoxy resin is at least one of glycidylamine epoxy resin, bisphenol F epoxy resin, hydrogenated bisphenol A, resorcinol epoxy resin, dicyclopentadiene epoxy resin, and biphenyl epoxy resin, and the epoxy value is 0.3-0.5; and / or The silicone-modified epoxy resin is selected from at least one of SILIKOPON EF, SILIKOPON ED, ALBIFLEX 246, ALBIFLEX296 and ALBIFLEX348; the polyether-modified epoxy resin is EP4000 of ADEKA; the polyurethane-modified epoxy resin is selected from at least one of EPU-6, EPU-73B, EPU-133T, SL3411, SL3412 and SL3413.

7. The bottom filling glue according to claim 1, characterized in that: The curing agent containing more than two amine groups is selected from at least one of 3,3'-diethyl 4,4'-diaminodiphenylmethane, diethyltoluenediamine, diaminodiphenylmethane, 3,-ethyl-4,4'-diaminodiphenylmethane, 2,4-diamino-3,5-dimethylthiotoluene, hendiamine, trimethylhexanediamine, metaphenylenediamine, and diaminodiphenyl ether.

8. The bottom filling glue according to claim 1, characterized in that: The coupling agent is at least one of an epoxy silane coupling agent, an amino silane coupling agent, an alkenyl silane coupling agent, and a urea silane coupling agent; preferably, the epoxy silane coupling agent and the urea silane coupling agent are compounded in a mass ratio of 2-4:1; Furthermore, the epoxy silane coupling agent is selected from at least one of γ-glycidyloxypropyl trimethoxysilane, γ-glycidyloxypropyl triethoxysilane, and γ-glycidyloxypropyl methyldiethoxysilane; the aminosilane coupling agent is selected from at least one of 3-(phenylamino)propyl trimethoxysilane, NN diethylaminopropyl trimethoxysilane, and γ-aminopropyl triethoxysilane; the urea silane coupling agent is selected from at least one of γ-ureapropyl trimethoxysilane and γ-ureapropyl triethoxysilane.

9. The bottom filling glue according to claim 1, characterized in that: The coupling agent modified spherical silicon micropowder has a D50 of 0.5-0.8 μm and a D100 of ≤3 μm; preferably, the coupling agent modified spherical silicon micropowder is prepared by a preparation method comprising the following steps: the spherical silicon micropowder is baked at 100-130°C for 4-6 hours for standby use, the silane coupling agent and the alcohol are prepared into a ball milling solution with a mass concentration of 1-3wt%, and the alcohol is selected from at least one of ethanol and isopropanol; the silane coupling agent is an aminosilane coupling agent, specifically selected from at least one of 3-(phenylamino)propyltrimethoxysilane, NN diethylaminopropyltrimethoxysilane, and γ-aminopropyltriethoxysilane; the baked spherical silicon micropowder and the ball milling solution are added to a ball mill in a mass ratio of 10-20:80-90, wet ball milled, and dried to obtain the coupling agent modified spherical silicon micropowder.

10. The method for preparing the bottom filler for anti-warping flip chip packaging according to any one of claims 1 to 9, characterized in that: The following steps are involved: Epoxy resin, flexible epoxy resin, maleimide resin and coupling agent are added into a vacuum double planetary stirring kettle, vacuumized and stirred until uniformly dispersed; the pressure is released, the temperature is raised to 50-70°C, pretreated spherical silicon powder is added and then stirred to obtain an epoxy resin composite, the epoxy resin composite is passed through three rollers and then ground three times, left to stand and mature, then stirred again and a curing agent is added, stirred to uniformly, vacuumized and pressure released to obtain a bottom filling adhesive for anti-warping flip chip packaging.

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