Low-moisture-absorption and high-temperature-resistant underfill adhesive as well as preparation method and application thereof

Abstract

The invention discloses a low-moisture-absorption and high-temperature-resistant underfill adhesive as well as a preparation method and application thereof. The low-moisture-absorption and high-temperature-resistant underfill adhesive is a product obtained by blending and reacting components including epoxy resin, low-viscosity benzoxazine resin, a curing agent, filler, a silane coupling agent and an optional curing accelerator. The underfill adhesive prepared by the invention not only has the advantages of high flow speed and short curing time, but also has the characteristics of high glass-transition temperature, low linear thermal expansion coefficient, high heat conductivity coefficient, low moisture absorption rate and the like after curing, and can greatly improve the packaging efficiency and prolong the service life.

Description

Technical Field

[0001] The present invention relates to the technical field of adhesives, and specifically relates to a low-moisture-absorbing and high-temperature-resistant underfill adhesive and its preparation method and application. Background Art

[0002] With the development of semiconductor packaging technology, the bump pitch of bare chips is getting smaller and smaller, which poses a great challenge to the underfill technology for flip chip packaging. The underfill process applies the underfill glue from the edge of the bare chip to the substrate, and uses the capillary action of the liquid to flow into the bottom of the bare chip and cure at a certain temperature to form a protection for the package, increasing the mechanical strength of the package. At the same time, more importantly, when the temperature changes, part of the stress and deformation generated by the mismatch of CTE between different materials such as the bare chip, substrate, and solder joints are absorbed, forming a certain degree of protection for the package body, enhancing the anti-drop performance between the chip and the substrate, alleviating the chip thermal stress, mechanical stress, etc., and improving the reliability and service life of the chip.

[0003] Currently, commercially available high-performance chip underfill adhesives (such as Loctite FP4526, Loctite FP4531, and Namish U8410-99) are generally prepared with epoxy resins of types such as bisphenol type, phenolic type, and biphenyl type as the matrix resin, adding curing agents, accelerators, and thermal conductive fillers. The underfill adhesive has strict requirements for the hydrolyzable chlorine content of the resin to avoid corrosion of the chip or circuit board due to moisture absorption in the environment. On the other hand, there are a large number of hydrophilic groups in the epoxy resin cured product system, such as hydroxyl groups, ether bonds, ether bonds, tertiary amine groups, etc., which have a significant impact on the moisture absorption rate of the resin and will reduce the service life of the flip chip. Currently, most underfill adhesives have good adhesion and insulation properties. However, as the use time extends and moisture in the air is inhaled, the chip will be in a high-temperature and high-humidity environment all the time, which is likely to cause the colloid to crack, delaminate, and the insulation performance to decline. Summary of the Invention

[0004] To solve the problems existing in the prior art, such as large moisture absorption rate and poor high-temperature resistance of the underfill adhesive, and the chip being in a high-temperature and high-humidity environment for a long time, which is likely to cause the colloid to crack, delaminate, and the insulation performance to decline, the present invention provides a low-moisture-absorbing and high-temperature-resistant underfill adhesive and its preparation method and application. The underfill adhesive prepared by the present invention not only has the advantages of fast flow rate and short curing time, but also has characteristics such as high glass transition temperature after curing, low linear thermal expansion coefficient, high thermal conductivity, and low moisture absorption rate, greatly improving the packaging efficiency and service life.

[0005] One of the objectives of the present invention is to provide a low-moisture-absorbing and high-temperature-resistant underfill adhesive, which is a product obtained by blending and reacting components including epoxy resin, low-viscosity benzoxazine resin, curing agent, filler, silane coupling agent, and optionally a curing accelerator.

[0006] In a preferred embodiment of the present invention,

[0007] Based on 100 parts by weight of the epoxy resin, the amounts of each component are as follows:

[0008] Low-viscosity benzoxazine resin: 30 - 100 parts by weight; preferably 35 - 80 parts by weight;

[0009] Curing agent: 10 - 140 parts by weight; preferably 10 - 110 parts by weight; more preferably 80 - 110 parts by weight;

[0010] Optionally, the curing accelerator: 0 - 15 parts by weight; preferably 0.1 - 10 parts by weight;

[0011] Filler: 300 - 600 parts by weight; preferably 350 - 450 parts by weight;

[0012] Silane coupling agent: 0.5 - 5 parts by weight; preferably 1 - 3 parts by weight.

[0013] In a preferred embodiment of the present invention,

[0014] The epoxy resin is one or more of glycidyl ether type epoxy resin, glycidyl amine type epoxy resin, alicyclic epoxy resin, and phenolic epoxy resin. Preferably, the viscosity of the epoxy resin is below 10000 mPa·s, more preferably below 5000 mPa·s, and even more preferably 100 - 5000 mPa·s, and the viscosity is tested at 25°C. The epoxy resin serves as the matrix material and plays a role in bonding the chip and the substrate.

[0015] In a preferred embodiment of the present invention,

[0016] The viscosity of the low-viscosity benzoxazine resin is below 1000 mPa·s, preferably 200 - 1000 mPa·s, and the viscosity test temperature is 25°C. Preferably, the low-viscosity benzoxazine resin is one or more of 3-ethynylaniline-phenol benzoxazine (abbreviated as PH-apa), 2-allylphenol-aniline benzoxazine (abbreviated as P-alp), allylamine-phenol benzoxazine (abbreviated as P-ala), aniline-cashew phenol benzoxazine (abbreviated as C-BOZ), hexamethylenediamine-phenol benzoxazine (abbreviated as PH-hda); the low-viscosity benzoxazine resin serves to reduce the overall viscosity of the resin, reduce the coefficient of thermal expansion, increase the Tg, and reduce the water absorption rate. The low-viscosity benzoxazine resin can be obtained commercially or prepared by any publicly known method in the prior art. Further preferably, the 3-ethynylaniline-phenol benzoxazine is preferably CG360L-1 of Chengdu Keyi High Polymer Technology Co., Ltd.; and / or, the 2-allylphenol-aniline benzoxazine is preferably CG360L-2 of Chengdu Keyi High Polymer Technology Co., Ltd.; and / or, the allylamine-phenol benzoxazine is preferably CG360L-3 of Chengdu Keyi High Polymer Technology Co., Ltd.; and / or, the aniline-cashew phenol benzoxazine is preferably CB6900-1 of Chengdu Keyi High Polymer Technology Co., Ltd.; and / or, the hexamethylenediamine-phenol benzoxazine is preferably CB6900-2 of Chengdu Keyi High Polymer Technology Co., Ltd.

[0017] In a preferred embodiment of the present invention,

[0018] The curing agent is one or more of liquid anhydride curing agents, preferably one or more of methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, and methylnadic anhydride. The curing agent serves to cure the epoxy resin.

[0019] In a preferred embodiment of the present invention,

[0020] The curing accelerator is one or more of 2-methylimidazole, 2-ethyl-4-methylimidazole, 2,4,6-tris(dimethylaminomethyl)phenol, quaternary ammonium salts, and quaternary phosphonium salts. The curing accelerator serves to accelerate the curing of the resin and shorten the heating time.

[0021] In a preferred embodiment of the present invention,

[0022] The maximum particle size of the filler ≤ 20 μm; and / or, the average particle size of the filler is 3 - 8 μm; preferably, the filler is one or more of spherical silica powder, spherical alumina, and spherical boron nitride. The filler serves to conduct heat and reduce the coefficient of thermal expansion.

[0023] In a preferred embodiment of the present invention,

[0024] The silane coupling agent is one or more of γ-aminopropyltriethoxysilane (domestic brand KH-550), γ-glycidoxypropyltrimethoxysilane (domestic brand KH-560), γ-methacryloxypropyltrimethoxysilane (domestic brand KH-570), γ-mercaptopropyltriethoxysilane (domestic brand KH-580), and γ-mercaptopropyltrimethoxysilane (domestic brand KH-590). The silane coupling agent plays a role in helping the filler disperse.

[0025] The low moisture absorption and high temperature resistant underfill glue of the present invention can also be added with various commonly used additives in the art according to processing needs, such as defoaming agents, internal lubricants, pigments, etc. Their dosages are all conventional dosages, or adjusted according to the requirements of the actual situation.

[0026] The second object of the present invention is to provide a preparation method of the low moisture absorption and high temperature resistant underfill glue of the first object of the present invention, including the step of mixing and stirring components including epoxy resin, low viscosity benzoxazine resin, curing agent, filler, silane coupling agent and optionally curing accelerator; preferably, the preparation method includes:

[0027] (1) Mix and stir the epoxy resin, low viscosity benzoxazine resin and filler, and then cool down.

[0028] (2) Add the silane coupling agent to the mixture obtained in step (1), mix and stir, and then cool down again.

[0029] (3) Add the curing agent and optionally the curing accelerator to the mixture obtained in step (2), mix and stir to obtain the low moisture absorption and high temperature resistant underfill glue.

[0030] In a preferred embodiment of the present invention,

[0031] In step (1),

[0032] The temperature of mixing and stirring is 60-100 °C, preferably 80-100 °C; and / or, the time of mixing and stirring is 0.2-5 hours, preferably 0.8-1.2 hours; and / or, the stirring rate is 100-300 r / min; and / or,

[0033] Cool down to a temperature of 40-60 °C, preferably 45-55 °C; and / or,

[0034] In step (2),

[0035] The time of mixing and stirring is 0.2-2 hours, preferably 0.4-0.6 hours; and / or, the stirring rate is 100-300 r / min; and / or,

[0036] Cool down to a temperature of 10 to 40°C again, preferably 10 to 30°C; and / or,

[0037] In step (3),

[0038] The mixing and stirring time is 0.2 to 2 hours, preferably 0.4 to 0.6 hours; and / or, the stirring rate is 100 to 300 r / min.

[0039] In a preferred embodiment of the present invention,

[0040] The mixing and stirring in steps (1), (2), and (3) are all carried out under vacuum.

[0041] The present invention can adopt the following specific technical solutions:

[0042] The preparation method of the low moisture absorption and high temperature resistant underfill glue includes:

[0043] (1) Weigh epoxy resin, low-viscosity benzoxazine resin and filler according to the ratio, put the above epoxy resin, low-viscosity benzoxazine resin and filler into a stirrer, and then stir rapidly under vacuum at 80 to 100°C for 0.8 to 1.2 hours, and cool down to 45 to 55°C;

[0044] (2) Then put in the metered amount of silane coupling agent, and continue to stir under vacuum for 0.4 to 0.6 hours, and release the pressure and cool down to room temperature;

[0045] (3) Continue to put in the metered amount of curing agent and optional accelerator, and then stir under vacuum for 0.4 to 0.6 hours to obtain the low moisture absorption and high temperature resistant underfill glue.

[0046] For the preparation method of the present invention, the mixing and curing processes of the raw material components can adopt the commonly used thermosetting resin processing processes in the prior art. The equipment used is also the commonly used equipment in the processing of thermosetting resins in the prior art.

[0047] The third object of the present invention is to provide an application of the low moisture absorption and high temperature resistant underfill glue of the first object of the present invention or the low moisture absorption and high temperature resistant underfill glue obtained by the preparation method of the second object of the present invention in the field of semiconductor packaging.

[0048] The low moisture absorption and high temperature resistant underfill glue of the present invention has the following advantages:

[0049] (1) The addition of low-viscosity benzoxazine resin can effectively reduce the moisture absorption rate of the underfill glue and play a role in improving the heat resistance.

[0050] (2) The underfill adhesive prepared by the present invention has the advantages of fast flow rate, short curing time, high glass transition temperature after curing, low moisture absorption rate, low coefficient of thermal expansion, and high thermal conductivity, and is suitable for underfilling in package types such as chip scale package (CSP) and ball grid array package (BGA). Detailed implementation manners

[0051] The present invention will be specifically described below in conjunction with specific embodiments. It is necessary to point out here that the following embodiments are only used for further illustration of the present invention and should not be construed as limiting the protection scope of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention still fall within the protection scope of the present invention.

[0052] The raw materials used in the embodiments are all conventional commercially available raw materials.

[0053]

Embodiment 1

[0054] (1) Weigh 100 g of bisphenol F type epoxy resin (viscosity 1200 mPa·s), 66.67 g of PH-apa (Chengdu Keyi High Polymer Technology Co., Ltd., grade CG360L-1, viscosity 700 mPa·s), and 400 g of spherical silica powder (average particle size 5 μm, maximum particle size 10 μm) and put them into a stirrer. Then, carry out rapid vacuum stirring at 80 °C (stirring rate 200 r / min) for 1 hour, and cool down to 45 °C;

[0055] (2) Then add 2 g of KH-560 silane coupling agent and continue vacuum stirring (stirring rate 200 r / min) for 0.5 hour, and release pressure and cool down to 25 °C;

[0056] (3) Continue to add 93.33 g of methylhexahydrophthalic anhydride and 6.67 g of 2-methylimidazole, and then carry out vacuum stirring (stirring rate 200 r / min) for 0.5 hour to obtain a low-moisture and high-temperature resistant underfill adhesive.

[0057]

Embodiment 2

[0058] (1) Weigh 80 g of bisphenol A type epoxy resin (viscosity 4000 mPa·s), 20 g of 3,4-epoxycyclohexylmethyl 3',4'-epoxycyclohexanecarboxylate (alicyclic epoxy resin), 66.67 g of PH-apa (Chengdu Keyi High Polymer Technology Co., Ltd., grade CG360L-1, viscosity 700 mPa·s), and 400 g of spherical silica powder (average particle size 5 μm, maximum particle size 10 μm) and put them into a stirrer. Then, carry out rapid vacuum stirring at 80 °C (stirring rate 200 r / min) for 1 hour, and cool down to 45 °C;

[0059] (2) Then add 2 g of silane coupling agent KH-560, and continue to stir under vacuum (stirring rate: 200 r / min) for 0.5 h. Then release the pressure and cool down to 25 °C.

[0060] (3) Then add 93.33 g of methylhexahydrophthalic anhydride and 6.67 g of 2-methylimidazole, and stir under vacuum (stirring rate: 200 r / min) for another 0.5 h to obtain a low moisture absorption and high temperature resistant underfill adhesive.

[0061]

Example 3

[0062] (1) Weigh 100 g of bisphenol F type epoxy resin (viscosity: 1200 mPa·s), 66.67 g of P-alp (Chengdu Keyi High Polymer Technology Co., Ltd., grade CG360L-2, viscosity: 400 mPa·s) and 400 g of spherical silica powder (average particle size: 5 μm, maximum particle size: 10 μm), and put them into a stirrer. Then stir rapidly under vacuum at 80 °C (stirring rate: 200 r / min) for 1 h, and cool down to 45 °C.

[0063] (2) Then add 2 g of silane coupling agent KH-560, and continue to stir under vacuum (stirring rate: 200 r / min) for 0.5 h. Then release the pressure and cool down to 25 °C.

[0064] (3) Then add 93.33 g of methylhexahydrophthalic anhydride and 6.67 g of 2-methylimidazole, and stir under vacuum (stirring rate: 200 r / min) for another 0.5 h to obtain a low moisture absorption and high temperature resistant underfill adhesive.

[0065]

Example 4

[0066] (1) Weigh 100 g of bisphenol F type epoxy resin (viscosity: 1200 mPa·s), 66.67 g of P-ala (Chengdu Keyi High Polymer Technology Co., Ltd., grade CG360L-3, viscosity: 350 mPa·s) and 400 g of spherical alumina (average particle size: 5 μm, maximum particle size: 10 μm), and put them into a stirrer. Then stir rapidly under vacuum at 80 °C (stirring rate: 200 r / min) for 1 h, and cool down to 45 °C.

[0067] (2) Then add 2 g of silane coupling agent KH-560, and continue to stir under vacuum (stirring rate: 200 r / min) for 0.5 h. Then release the pressure and cool down to 25 °C.

[0068] (3) Then add 93.33 g of methylhexahydrophthalic anhydride and 6.67 g of 2-methylimidazole, and stir under vacuum (stirring rate: 200 r / min) for another 0.5 h to obtain a low moisture absorption and high temperature resistant underfill adhesive.

[0069]

Example 5

[0070] (1) Weigh 100 g of bisphenol F epoxy resin (viscosity 1200 mPa·s), 66.67 g of PH-apa (Chengdu Keyi High Polymer Technology Co., Ltd., grade CG360L-1, viscosity 700 mPa·s), and 400 g of spherical silica powder (average particle size 5 μm, maximum particle size 10 μm), put them into a stirrer, and then rapidly stir under vacuum at 80 °C (stirring rate 200 r / min) for 1 hour, and cool down to 45 °C;

[0071] (2) Then add 2 g of silane coupling agent KH-570, and continue to stir under vacuum (stirring rate 200 r / min) for 0.5 hour, and release the pressure and cool down to 25 °C;

[0072] (3) Continue to add 93.33 g of methyltetrahydrophthalic anhydride and 6.67 g of 2-methylimidazole, and then stir under vacuum (stirring rate 200 r / min) for 0.5 hour to obtain a low moisture absorption and high temperature resistant underfill adhesive.

[0073]

Example 6

[0074] (1) Weigh 100 g of bisphenol F epoxy resin (viscosity 1200 mPa·s), 66.67 g of PH-apa (Chengdu Keyi High Polymer Technology Co., Ltd., grade CG360L-1, viscosity 700 mPa·s), and 400 g of spherical silica powder (average particle size 5 μm, maximum particle size 10 μm), put them into a stirrer, and then rapidly stir under vacuum at 80 °C (stirring rate 200 r / min) for 1 hour, and cool down to 45 °C;

[0075] (2) Then add 2 g of silane coupling agent KH-560, and continue to stir under vacuum (stirring rate 200 r / min) for 0.5 hour, and release the pressure and cool down to 25 °C;

[0076] (3) Continue to add 93.33 g of methylhexahydrophthalic anhydride and 6.67 g of 2,4,6-tris(dimethylaminomethyl)phenol, and then stir under vacuum (stirring rate 200 r / min) for 0.5 hour to obtain a low moisture absorption and high temperature resistant underfill adhesive.

[0077]

Example 7

[0078] (1) Weigh 100 g of bisphenol F epoxy resin (viscosity 1200 mPa·s), 35 g of PH-apa (Chengdu Keyi High Polymer Technology Co., Ltd., grade CG360L-1, viscosity 700 mPa·s), and 400 g of spherical silica powder (average particle size 5 μm, maximum particle size 10 μm), put them into a stirrer, and then rapidly stir under vacuum at 80 °C (stirring rate 200 r / min) for 1 hour, and cool down to 45 °C;

[0079] (2) Then add 2 g of silane coupling agent KH-560, and continue to stir under vacuum (stirring rate: 200 r / min) for 0.5 hour. Then release the pressure and cool down to 25 °C;

[0080] (3) Then add 93.33 g of methylhexahydrophthalic anhydride and 6.67 g of 2-methylimidazole, and stir under vacuum (stirring rate: 200 r / min) for 0.5 hour to obtain a low moisture absorption and high temperature resistant underfill adhesive.

[0081]

Example 8

[0082] (1) Weigh 100 g of bisphenol F type epoxy resin (viscosity: 1200 mPa·s), 66.67 g of PH-apa (Chengdu Keyi High Polymer Technology Co., Ltd., grade CG360L-1, viscosity: 700 mPa·s) and 400 g of spherical silica powder (average particle size: 5 μm, maximum particle size: 10 μm), and put them into a stirrer. Then stir rapidly under vacuum at 80 °C (stirring rate: 200 r / min) for 1 hour, and cool down to 45 °C;

[0083] (2) Then add 2 g of silane coupling agent KH-560, and continue to stir under vacuum (stirring rate: 200 r / min) for 0.5 hour. Then release the pressure and cool down to 25 °C;

[0084] (3) Then add 19.33 g of 1,3-cyclohexanedimethanamine and 6.67 g of 2-methylimidazole, and stir under vacuum (stirring rate: 200 r / min) for 0.5 hour to obtain a low moisture absorption and high temperature resistant underfill adhesive.

[0085]

Example 9

[0086] (1) Weigh 100 g of bisphenol F type epoxy resin (viscosity: 1200 mPa·s), 20 g of PH-apa (Chengdu Keyi High Polymer Technology Co., Ltd., grade CG360L-1, viscosity: 700 mPa·s) and 400 g of spherical silica powder (average particle size: 5 μm, maximum particle size: 10 μm), and put them into a stirrer. Then stir rapidly under vacuum at 80 °C (stirring rate: 200 r / min) for 1 hour, and cool down to 45 °C;

[0087] (2) Then add 2 g of silane coupling agent KH-560, and continue to stir under vacuum (stirring rate: 200 r / min) for 0.5 hour. Then release the pressure and cool down to 25 °C;

[0088] (3) Then add 93.33 g of methylhexahydrophthalic anhydride and 6.67 g of 2-methylimidazole, and stir under vacuum (stirring rate: 200 r / min) for 0.5 hour to obtain a low moisture absorption and high temperature resistant underfill adhesive.

[0089]

Example 10

[0090] (1) Weigh 100 g of bisphenol F epoxy resin (viscosity 1200 mPa·s), 150 g of PH-apa (Chengdu Keyi High Polymer Technology Co., Ltd., grade CG360L-1, viscosity 700 mPa·s), and 400 g of spherical silica powder (average particle size 5 μm, maximum particle size 10 μm) and put them into a stirrer. Then, stir rapidly under vacuum at 80 °C (stirring rate 200 r / min) for 1 hour, and cool down to 45 °C;

[0091] (2) Then, add 2 g of silane coupling agent KH-560, and continue to stir under vacuum (stirring rate 200 r / min) for 0.5 hour. Release the pressure and cool down to 25 °C;

[0092] (3) Continue to add 93.33 g of methylhexahydrophthalic anhydride and 6.67 g of 2-methylimidazole, and then stir under vacuum (stirring rate 200 r / min) for 0.5 hour to obtain a low moisture absorption and high temperature resistant underfill adhesive.

[0093]

Example 11

[0094] (1) Weigh 100 g of bisphenol F epoxy resin (viscosity 1200 mPa·s), 66.67 g of diphenylmethane diamine-based benzoxazine (Chengdu Keyi High Polymer Technology Co., Ltd., grade 6600, solid powder), and 400 g of spherical silica powder (average particle size 5 μm, maximum particle size 10 μm) and put them into a stirrer. Then, stir rapidly under vacuum at 80 °C (stirring rate 200 r / min) for 1 hour, and cool down to 45 °C;

[0095] (2) Then, add 2 g of silane coupling agent KH-560, and continue to stir under vacuum (stirring rate 200 r / min) for 0.5 hour. Release the pressure and cool down to 25 °C;

[0096] (3) Continue to add 93.33 g of methylhexahydrophthalic anhydride and 6.67 g of 2-methylimidazole, and then stir under vacuum (stirring rate 200 r / min) for 0.5 hour to obtain a low moisture absorption and high temperature resistant underfill adhesive.

[0097]

Comparative Example 1

Without adding low viscosity benzoxazine resin

[0098] (1) Weigh 100 g of bisphenol F epoxy resin (viscosity 1200 mPa·s) and 400 g of spherical silica powder (average particle size 5 μm, maximum particle size 10 μm) and put them into a stirrer. Then, stir rapidly under vacuum at 80 °C (stirring rate 200 r / min) for 1 hour, and cool down to 45 °C;

[0099] (2) Then, add 2 g of silane coupling agent KH-560, and continue to stir under vacuum (stirring rate 200 r / min) for 0.5 hour. Release the pressure and cool down to 25 °C;

[0100] (3) Continuously add 93.33 g of methylhexahydrophthalic anhydride and 6.67 g of 2-methylimidazole, and then stir under vacuum (stirring rate: 200 r / min) for 0.5 hour to obtain the underfill adhesive.

[0101]

Comparative Example 2

Without silane coupling agent

[0102] (1) Weigh 100 g of bisphenol F type epoxy resin (viscosity 1200 mPa·s), 66.67 g of PH-apa (Chengdu Keyi High Polymer Technology Co., Ltd., grade CG360L-1, viscosity 700 mPa·s), and 400 g of spherical silica powder (average particle size 5 μm, maximum particle size 10 μm), and put them into a stirrer. Then, stir rapidly under vacuum at 80°C (stirring rate: 200 r / min) for 1 hour, release the pressure and cool down to 25°C;

[0103] (2) Continuously add 93.33 g of methylhexahydrophthalic anhydride and 6.67 g of 2-methylimidazole, and then stir under vacuum (stirring rate: 200 r / min) for 0.5 hour to obtain the underfill adhesive.

[0104]

Test Example

[0105] Test the underfill adhesives of the above Examples 1 to 11 and Comparative Examples 1 to 2 of the present invention through the following tests.

[0106] Test 1 Flow Time Test

[0107] Use a device composed of a spacer and a cover glass and a slide glass with a gap of 50 μm (simulating the gap of packaged components), and conduct a flow time test on the samples obtained from the above Examples 1 to 11 and Comparative Examples 1 to 2 according to the test method of semiconductor industry standard J-STD-030.

[0108] Test 2 Curing Time Test

[0109] Test the samples obtained from the above Examples 1 to 11 and Comparative Examples 1 to 2 according to the standard GB / T14074-2006.

[0110] Test 3 Glass Transition Temperature Test

[0111] Test the samples obtained from the above Examples 1 to 11 and Comparative Examples 1 to 2 according to the standard ASTM D696-79.

[0112] Test 4 Coefficient of Linear Thermal Expansion Test

[0113] Test the samples obtained from the above Examples 1 to 11 and Comparative Examples 1 to 2 according to the standard ASTM D696-79.

[0114] Test 5 Thermal Conductivity Test

[0115] Using the TPS2500S thermal conductivity measuring instrument of Hot Disk Company, the samples obtained from the above Examples 1-11 and Comparative Examples 1-2 were tested according to the standard ASTM D5470.

[0116] Test 6 Moisture Absorption Rate Test

[0117] The samples obtained from the above Examples 1-11 and Comparative Examples 1-2 were tested according to the standard GB / T5170.5-2008.

[0118] The test results of the above examples and comparative examples are shown in Table 1 below.

[0119] Table 1 Comparison of Underfill Adhesive Properties of Examples and Comparative Examples

[0120]

[0121] It can be seen from Examples 1-11 and Table 1 that the underfill adhesive prepared by the present invention not only has a fast flow rate and a short curing time, but also has the characteristics of a high glass transition temperature, a low linear thermal expansion coefficient, a high thermal conductivity, and a low moisture absorption rate after curing, which can greatly improve the packaging efficiency and service life. In addition, when the amount of the low-viscosity benzoxazine resin is preferably in the range of 30-100 parts by weight, the overall performance of the obtained underfill adhesive is more excellent.

Claims

1. A low moisture absorption and high temperature resistant underfill adhesive, which is a product obtained by blending and reacting components including epoxy resin, low viscosity benzoxazine resin, curing agent, filler, silane coupling agent and optionally a curing accelerator.

2. The low moisture absorption and high temperature resistant underfill adhesive according to claim 1, characterized in that: Based on 100 parts by weight of epoxy resin, the amounts of each component are as follows, 3. The low moisture absorption and high temperature resistant underfill adhesive according to claim 1, characterized in that: The epoxy resin is one or more of glycidyl ether type epoxy resin, glycidyl amine type epoxy resin, alicyclic epoxy resin, phenolic epoxy resin. Preferably, the viscosity of the epoxy resin is below 10000 mPa·s.

4. The low moisture absorption and high temperature resistant underfill adhesive according to claim 1, characterized in that: The viscosity of the low viscosity benzoxazine resin is below 1000 mPa·s. Preferably, the low viscosity benzoxazine resin is one or more of 3-ethynylaniline-phenol type benzoxazine, 2-allylphenol-aniline type benzoxazine, allylamine-phenol type benzoxazine, aniline-cashew phenol type benzoxazine, hexamethylenediamine-phenol type benzoxazine.

5. The low moisture absorption and high temperature resistant underfill adhesive according to claim 1, characterized in that: The curing agent is one or more of liquid anhydride curing agents, preferably one or more of methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride.

6. The low moisture absorption and high temperature resistant underfill adhesive according to claim 1, characterized in that: The curing accelerator is one or more of 2-methylimidazole, 2-ethyl-4-methylimidazole, 2,4,6-tris(dimethylaminomethyl)phenol, quaternary ammonium salt, quaternary phosphonium salt.

7. The low moisture absorption and high temperature resistant underfill adhesive according to claim 1, characterized in that: The maximum particle size of the filler ≤ 20 μm; and / or, the average particle size of the filler is 3 - 8 μm; Preferably, the filler is one or more of spherical silica powder, spherical alumina, spherical boron nitride.

8. The low moisture absorption and high temperature resistant underfill adhesive according to claim 1, characterized in that: The silane coupling agent is one or more of γ-aminopropyltriethoxysilane, γ-glycidyletheroxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane.

9. A preparation method of the low moisture absorption and high temperature resistant underfill adhesive according to any one of claims 1-8, including the step of mixing and stirring components including epoxy resin, low viscosity benzoxazine resin, curing agent, filler, silane coupling agent and optionally a curing accelerator; Preferably, the preparation method comprises: (1) Mixing and stirring epoxy resin, low viscosity benzoxazine resin and filler, and then cooling; (2) Adding silane coupling agent to the mixture obtained in step (1), mixing and stirring, and then cooling again; (3) Adding curing agent and optionally a curing accelerator to the mixture obtained in step (2), mixing and stirring to obtain the low moisture absorption and high temperature resistant underfill adhesive.

10. The preparation method according to claim 9, characterized in that: in step (1), the temperature of the mixing and stirring is 60 to 100 °C, preferably 80 to 100 °C; and / or, the time of the mixing and stirring is 0.2 to 5 hours, preferably 0.8 to 1.2 hours; and / or, the stirring rate is 100 to 300 r / min; and / or, cool down to a temperature of 40 to 60 °C, preferably 45 to 55 °C; and / or, in step (2), the time of the mixing and stirring is 0.2 to 2 hours, preferably 0.4 to 0.6 hours; and / or, the stirring rate is 100 to 300 r / min; and / or, cool down again to a temperature of 10 to 40 °C, preferably 10 to 30 °C; and / or, in step (3), the time of the mixing and stirring is 0.2 to 2 hours, preferably 0.4 to 0.6 hours; and / or, the stirring rate is 100 to 300 r / min.

11. The preparation method according to claim 9, characterized in that: the mixing and stirring in steps (1), (2) and (3) are all carried out under vacuum.

12. Application of a low moisture absorption and high temperature resistant underfill glue according to any one of claims 1-8 or a low moisture absorption and high temperature resistant underfill glue obtained by the preparation method according to any one of claims 9-11 in the field of semiconductor packaging.

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