A latent accelerator capable of reducing the curing stress of epoxy resin, its preparation method and application

Abstract

The present invention provides a latent accelerator capable of reducing the curing stress of epoxy resin, and its preparation method and application. The structural formula of the latent accelerator is shown as formula I below. The structure of this accelerator contains both a phosphonium silicate ion structural unit capable of promoting the curing of epoxy resin and a linear polymer structural unit capable of reducing the curing stress of epoxy resin. While acting as an accelerator for epoxy resin, it can endow epoxy resin with advantages such as good fluidity, curability and low curing stress. The present invention also provides an epoxy resin composition containing a linear polymer accelerator capped with phosphonium silicate ions. When encapsulating semiconductor devices using this epoxy resin composition, it has low curing warpage and high encapsulation reliability.

Description

Technical Field

[0001] The present invention relates to a latent accelerator capable of reducing the curing stress of epoxy resin, a preparation method thereof and an application thereof, and belongs to the technical field of epoxy resin. Background Art

[0002] In the field of semiconductor device packaging, it can be divided into three categories according to different materials: plastic packaging, ceramic packaging and metal packaging. Considering factors such as production efficiency and cost, plastic packaging has become the mainstream. Epoxy resin packaging materials are widely used in the packaging of integrated circuits because of their excellent processability and low cost, and the finally cured molded products have outstanding advantages such as good mechanical properties, heat resistance, electrical insulation properties and corrosion resistance.

[0003] However, with the development of integrated circuit components towards miniaturization, thinning and high integration, the integration degree of chips is getting higher and higher, and high-density and large-size packaging have become the general trend of electronic packaging. Therefore, the requirements for the refinement degree of packaging by chips are getting stricter and stricter, and some problems that cannot be solved by traditional epoxy packaging materials have emerged.

[0004] First of all, epoxy resin packaging materials generally use processes such as transfer molding or compression molding for packaging. The high density of integrated circuits makes the wiring pitch of chips narrower and narrower. Excessive resin viscosity and an increase in viscosity during the flow process may cause incomplete wiring packaging. This requires that the resin composition has good transfer fluidity at the molding process temperature, and the fluidity will not be reduced due to the addition of a large amount of inorganic filler components; at the same time, in order to improve the packaging efficiency and avoid situations such as overflow and leakage of materials at the molding temperature, the resin is also required to have fast curing performance. Currently commonly used accelerators such as triphenylphosphine and triphenylphosphine-benzoquinone adducts can still catalyze the curing of epoxy resin at a lower temperature, causing the epoxy molding compound to continue to undergo a curing reaction during storage, preheating and transfer flow processes, resulting in an increase in resin viscosity and a decrease in fluidity, and this change in state is uneven, thus seriously affecting the resin flow filling property during packaging and the reliability of packaged devices. Therefore, one of the problems to be solved is to provide a latent accelerator that can endow epoxy resin packaging materials with excellent fluidity and high-temperature fast curing properties.

[0005] Secondly, the thinning and large-size packaging of integrated circuits have put forward higher requirements on the curing stress of epoxy resin packaging materials. When using traditional epoxy resin materials for packaging, there are disadvantages such as high curing stress and large warping deformation, which may further lead to problems such as dislocation of metal wiring and cracks in silicon chips, seriously affecting the reliability of packaging. At present, the main method to reduce the stress of epoxy packaging materials is to add stress absorbers such as silicone oil and silicone resin or stress modifiers such as nitrile rubber, polysulfide rubber, and polyether elastomers to reduce stress by reducing the bending modulus of the cured product. However, modifiers such as silicone oil are not easy to ooze out with resin, causing problems such as scars, poor bonding, and interface stratification in the packaged device; and elastomers such as rubber have the disadvantages of reducing the heat resistance of the resin and limited improvement in stress after addition. Therefore, the development of efficient low-stress modifiers to reduce the curing stress of epoxy resin packaging materials is also one of the problems to be solved urgently. Summary of the invention

[0006] The object of the present invention is to provide a latent accelerator capable of reducing the curing stress of epoxy resin, and as an epoxy resin accelerator, the latent accelerator can give the epoxy resin excellent fluidity, curing property, storage property, mechanical properties and extremely low curing stress.

[0007] The structural formula of the phosphonium silicate ion-terminated linear polymer accelerator provided by the present invention is shown in the following formula I:

[0008]

[0009] In formula I, A is -Si(CH3)2O-, -Si(CH3)(Ph)O-, -Si(Ph)2O-, -CH2CH2O-,

[0010] One or more copolymerized repeating units of -CH(CH3)CH2O- and -CH2CH2CH2CH2O-, wherein n is an integer greater than 2;

[0011] Ar is selected from aromatic groups;

[0012] R1, R2, R3 and R4 are independently selected from phenyl, benzyl or C1-C6 alkyl;

[0013] -X1-Y1- and -X2-Y2- are both selected from silicon atoms and molecular chains connecting phosphonium silicate ions -(A) n -, the two may be the same or different.

[0014] Preferably, in formula I, n is an integer from 5 to 100, such as 15 to 50. When n is less than 5, the molecular weight and content of the flexible chain segments in the linear polymer promoter are low, and it is difficult to achieve the effect of reducing the curing stress of the epoxy resin. When n is greater than 100, the content of phosphonium silicate ions in the linear polymer promoter is low, which affects the curing of the epoxy resin and the properties of the cured product.

[0015] Ar is selected from phenyl, naphthyl, biphenyl, and binaphthyl;

[0016] -X1-Y1- and -X2-Y2- are organic groups containing -S-CH2-CH2- or -CH2-CH2- units formed by thiol-ene click reaction or hydrosilylation reaction, such as -CH2CH2SCH2CH2CH2- or -CH2CH2-. The linear polymer promoter of the present invention can be prepared according to the following method:

[0017] (1) The vinyl-terminated polymer shown in formula 1 reacts with the functional group-containing trialkoxysilane shown in formula 2 to obtain a trialkoxysilane-terminated polymer intermediate shown in formula 3. The reaction equation is as follows:

[0018]

[0019] In each formula, A is one or several copolymerized repeating units selected from -Si(CH3)2O-, -Si(CH3)(Ph)O-, -Si(Ph)2O-, -CH2CH2O-, -CH(CH3)CH2O-, and -CH2CH2CH2CH2O-; n is an integer greater than 2, preferably an integer from 5 to 100; Y1 and Y2 are both alkyl groups with 1 to 6 carbon atoms; R7 is an alkyl group with 1 to 3 carbon atoms; X’ is a hydrogen atom or 3-mercaptopropyl; X1 and X2 are organic groups formed by the addition of the terminal double bond in formula 1 to X’ in formula 2.

[0020] (2) The trialkoxysilane-terminated polymer intermediate shown in formula 3, the proton donor containing an aromatic ring structure shown in formula 4, and the alkali metal alkoxide shown in formula 5 react to obtain a silicate-terminated polymer intermediate shown in formula 6. The reaction equation is as follows:

[0021]

[0022] In each formula, Ar is selected from aromatic groups;

[0023] M represents lithium, sodium, or potassium;

[0024] R’ is an alkyl group with 1 to 3 carbon atoms;

[0025] The definitions of -X1-Y1-, -X2-Y2-, and A are the same as those in formula 3;

[0026] (3) The silicate-capped polymer intermediate shown in formula (6) reacts with the phosphonium halide compound shown in formula (7) to obtain the phosphonium silicate ion-capped linear polymer promoter described in claim 1 or 2;

[0027]

[0028] In formula (7), R1, R2, R3 and R4 are independently selected from phenyl, benzyl or C1-C6 alkyl, and X is chlorine or bromine.

[0029] In step (2), the proton donor with an aromatic ring structure shown in formula (4) is preferably catechol, 1,2-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,2'-dihydroxybiphenyl or 2,2'-binaphthol;

[0030] The alkali metal alkoxide shown in formula (5) is preferably lithium methoxide, sodium methoxide, sodium ethoxide, potassium methoxide or potassium ethoxide;

[0031] In step (3), the phosphonium halide compound shown in formula (7) is preferably a phosphonium halide such as tetrabutylphosphonium chloride, tetrabutylphosphonium bromide, methyltriphenylphosphonium chloride, methyltriphenylphosphonium bromide, tetraphenylphosphonium chloride, tetraphenylphosphonium bromide, benzyltriphenylphosphonium chloride or benzyltriphenylphosphonium bromide.

[0032] The molecular structure of the phosphonium silicate ion-capped linear polymer promoter provided by the present invention simultaneously contains a phosphonium silicate ion unit capable of promoting the curing of epoxy resin and a flexible polymer unit capable of reducing the curing stress of epoxy resin. On the one hand, the silicate anion complexes with the phosphonium ion, inhibiting the activity of the phosphonium ion to promote the curing reaction, and the silicate anion connected to the polymer chain has a better inhibitory effect, so that the epoxy resin composition has excellent medium and high temperature melt fluidity and low temperature storage properties; on the other hand, at high temperature, the silicate anion dissociates from the phosphonium ion, and the highly active phosphonium ion can promote the rapid curing of epoxy resin. At the same time, the flexible polymer capped by the silicate anion can relax the stress generated during the curing reaction in situ through molecular chain movement, so that the epoxy resin composition has high temperature rapid curing and extremely low curing residual stress; in addition, due to the low nucleophilicity of the silicate anion capping the flexible polymer unit in the promoter of the present invention after dissociation at high temperature, it does not participate in the curing crosslinking of epoxy resin, but is uniformly dispersed in the entire epoxy network, not only having little impact on the heat resistance of epoxy resin, but also having a good toughening effect on the cured product of epoxy resin.

[0033] Based on the structural advantages of the phosphonium silicate ion-capped linear polymer promoter, the present invention also provides an epoxy resin composition with good fluidity, curability and low curing stress characteristics, including the following components (A)-(C) or (A)-(D):

[0034] (A) An epoxy resin compound having at least two epoxy groups in its molecular structure;

[0035] (B) A phenolic resin compound having at least two phenolic hydroxyl groups in its molecular structure;

[0036] (C) A linear polymer accelerator capped with a phosphonium silicate ion represented by formula (I);

[0037] (D) An inorganic filler.

[0038] In the above epoxy resin composition, component A refers to all monomers, oligomers and polymers having two or more epoxy groups in one molecule, and its molecular structure and molecular weight are not particularly limited, and it can be selected from one or a combination of several of glycidyl ether type epoxy resins, glycidyl amine type epoxy resins, glycidyl ester type epoxy resins and alicyclic epoxy resins; further, it can be selected from one or a combination of several of phenol novolak type epoxy resins, cresol novolak type epoxy resins, naphthol novolak type epoxy resins, bisphenol A type epoxy resins, bisphenol F type epoxy resins, biphenyl type epoxy resins, triphenol methane type epoxy resins, phenol aralkyl type epoxy resins, naphthol aralkyl type epoxy resins, dicyclopentadiene modified phenol type epoxy resins, naphthalenediol, anthracenediol type epoxy resins, bisphenol fluorene type epoxy resins and isocyanuric acid triglycidyl ester.

[0039] In the above epoxy resin composition, component B refers to all monomers, oligomers and polymers having two or more phenolic hydroxyl groups in one molecule, and its molecular structure and molecular weight are not particularly limited, and it can be selected from one or a combination of several of linear phenolic resins, phenol aralkyl resins, bisphenols and polyphenol monomers and poly(p-hydroxystyrene); further, it can be selected from one or a combination of several of phenol, o-cresol, tert-butylphenol, bisphenol A, naphthol type linear phenolic resins, phenol aralkyl resins containing phenylene or biphenylene groups, triphenol methane, phenolic resins containing triphenol methane structure, bisphenol A, bisphenol F and poly(p-hydroxystyrene).

[0040] In the above epoxy resin composition, component D is an inorganic filler, and the purpose is to improve the properties such as the coefficient of thermal expansion, water absorption rate and thermal conductivity of the cured product, and its type is not particularly limited, and it can be selected from one or a combination of several of silica, alumina, silicon carbide, titanium dioxide, aluminum nitride, boron nitride, aluminum hydroxide, calcium carbonate, barium sulfate, wollastonite, clay and glass fiber.

[0041] In the above epoxy resin composition, the mass ratio of component C is preferably 1% to 25% of the mass of component A, and more preferably 3% to 15%. Within this range, a good balance is obtained among the curability, fluidity, curing stress and properties of the cured product of the epoxy resin composition.

[0042] In the above epoxy resin composition, there are no special requirements for the mixing ratio of component A and component B. Preferably, for 1 mol of epoxy groups in component A, the phenolic hydroxyl groups in component B are 0.5 to 2.0 mol, and more preferably 0.7 to 1.5 mol. Within this range, various properties of the epoxy resin cured product can maintain a proper balance.

[0043] In the above epoxy resin composition, there are no special requirements for the dosage of component D. Preferably, for 100 parts by mass of component A and component B, the content of component D is preferably 100 to 1900 parts by mass, and more preferably 400 to 1300 parts by weight. Within this range, the epoxy resin cured product has low hygroscopicity, low linear thermal expansion coefficient and good mechanical strength, and the composition has good fluidity when melted by heating.

[0044] In addition to the above components A to D, the epoxy resin composition of the present invention may further contain various additives, such as flame retardants such as brominated epoxy resin, antimony oxide or phosphorus-containing compounds, colorants such as carbon black or iron oxide, plasma scavengers such as hydrotalcite, mold release agents such as stearic acid, stearate, polyethylene wax, coupling agents such as epoxy group silane, mercapto group silane, phthalate ester, and antioxidants such as 2,6-di-tert-butyl-p-cresol, pentaerythritol tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], and so on.

[0045] The above epoxy resin composition can be prepared by the following method:

[0046] Component A, component B, component C and other additives, or component A, component B, component C, component D and other additives are mixed by high-speed stirring, and then the obtained mixture is melt-kneaded using a twin-screw extruder. After being uniform, it is quickly calendered and cooled into sheets, and finally pulverized into powder to obtain the product.

[0047] The epoxy resin composition provided by the present invention can be used as a packaging resin, and is cured and formed by molding processes such as transfer molding and compression molding to package semiconductor devices.

[0048] In addition, the application of the epoxy resin composition of the present invention is not limited to this. According to different uses of the epoxy resin composition of the present invention, inorganic fillers may not be added.

[0049] Compared with the prior art, the present invention has the following advantages:

[0050] (1) Since the epoxy resin composition provided by the present invention uses a linear polymer capped with phosphonium silicate ions as a promoter, it has excellent fluidity, curability, storage stability, mechanical properties and extremely low curing stress. The packaged semiconductor device has advantages such as small warpage deformation, and the packaging reliability is higher;

[0051] (2) Compared with the commonly used phosphonium accelerators, the linear polymer accelerator capped with silicate phosphonium ions provided by the present invention has good compatibility with epoxy resins and curing agents and better processability due to the presence of a polymer chain and the flexible design of the polymer chain structure. Detailed implementation mode

[0052] Unless otherwise specified, the experimental methods used in the following examples are all conventional methods.

[0053] Unless otherwise specified, the materials, reagents, etc. used in the following examples can all be obtained from commercial channels.

[0054] Example 1. Synthesis of accelerator C1

[0055] (1) Add 50 g of vinyl-capped polymethylphenylsiloxane (as shown in Formula 1, A is -Si(CH3)(Ph)O-, n is 15), 20 g of trimethoxysilane (as shown in Formula 2, R7 is methyl, X' is hydrogen atom), 25 g of toluene and 0.007 g of chloroplatinic acid catalyst into a 250 ml three-necked flask protected by nitrogen. After stirring evenly at room temperature, slowly heat up to 70 °C and react for 10 hours. After the reaction is completed, distill under reduced pressure at 200 Pa and 100 °C for 2 hours to remove toluene and unreacted trimethoxysilane to obtain trimethoxysilane-capped polymethylphenylsiloxane (as shown in Formula 3, -X1-Y1- and -X2-Y2- are both -CH2CH2-).

[0056] (2) Add 25 g of trimethoxysilane-capped polymethylphenylsiloxane shown in Formula 3, 4.8 g of 2,3-dihydroxynaphthalene (Formula 4, Ar is naphthyl) and 25 g of absolute ethanol into a 250 ml three-necked flask. After dissolving and mixing evenly, dissolve 0.8 g of sodium methoxide (Formula 5, M is methyl, R' is sodium) in 10 g of absolute ethanol and drop it into the three-necked flask. After dropping, react at 75 °C for 12 hours. Then dissolve 5.5 g of tetraphenylphosphonium bromide (Formula 7, R1, R2, R3 and R4 are all phenyl, X is bromine) in 20 g of absolute ethanol, slowly drop it into the three-necked flask, and continue to react for 4 hours after dropping. Wash the reaction product three times with 150 g of absolute ethanol and dry it under vacuum at 100 °C for 12 hours to obtain 35 g of the silicate phosphonium ion-capped polymethylphenylsiloxane accelerator C1.

[0057] The silicate phosphonium ion-capped polymethylphenylsiloxane accelerator C1 prepared in this example is as shown in Formula I, where R1, R2, R3 and R4 are all phenyl, Ar is naphthyl, A is -Si(CH3)(Ph)O-, -X1-Y1- and -X2-Y2- are -CH2CH2-, and n is 15.

[0058] Example 2. Synthesis of accelerator C2

[0059] (1) Add 45 g of vinyl-terminated polyoxyethylene ether (as shown in Formula 1, A is -CH2CH2O-, n is 50), 30 g of 3-mercaptopropyltrimethoxysilane (as shown in Formula 3, R7 is methyl, X' is 3-mercaptopropyl), 25 g of toluene, and 0.05 g of azobisisobutyronitrile catalyst into a 250 ml three-necked flask under nitrogen protection. After stirring evenly at room temperature, slowly raise the temperature to 60 °C and react for 20 hours. After the reaction is completed, distill under reduced pressure at 200 Pa and 150 °C for 2 hours to remove toluene and unreacted 3-mercaptopropyltrimethoxysilane to obtain polyoxyethylene ether terminated with trimethoxysilane (as shown in Formula 3, -X1-Y1- and -X2-Y2- are both -CH2CH2SCH2CH2CH2-).

[0060] (2) Add 30 g of polyoxyethylene ether terminated with trimethoxysilane shown in Formula 3, 5.2 g of 2,2'-dihydroxybiphenyl (Formula 4, Ar is biphenyl), and 25 g of absolute ethanol into a 250 ml three-necked flask. After dissolving and mixing evenly, dissolve 0.8 g of sodium methoxide (Formula 5, M is methyl, R' is sodium) in 10 g of absolute ethanol and drop it into the three-necked flask. After the dropping is completed, react at 75 °C for 12 hours. Then dissolve 5.5 g of tetraphenylphosphonium bromide (Formula 7, R1, R2, R3, and R4 are all phenyl, X is bromine) in 20 g of absolute ethanol, slowly drop it into the three-necked flask, and continue to react for 4 hours after the dropping is completed. Wash the reaction product three times with 150 g of absolute ethanol and dry it under vacuum at 100 °C for 12 hours to obtain 32 g of polyoxyethylene ether promoter C2 terminated with phosphonium silicate ions.

[0061] The polyoxyethylene ether promoter C2 terminated with phosphonium silicate ions prepared in this example is as shown in Formula I, where R1, R2, R3, and R4 are all phenyl, Ar is biphenyl, A is -CH2CH2O-, -X1-Y1- and -X2-Y2- are -CH2CH2SCH2CH2CH2-, and n is 50.

[0062] Example 3. Synthesis of Promoter C3

[0063] (1) 44 g of vinyl-terminated polydimethylsiloxane (as shown in Formula 1, A is -Si(CH3)2O-, n is 40), 28 g of 3-mercaptopropyltrimethoxysilane (as shown in Formula 3, R7 is methyl, X' is 3-mercaptopropyl), 25 g of toluene and 0.05 g of azobisisobutyronitrile catalyst were added to a 250 ml three-necked flask under nitrogen protection. After stirring evenly at room temperature, the temperature was slowly raised to 60 °C and reacted for 20 hours. After the reaction was completed, toluene and unreacted 3-mercaptopropyltrimethoxysilane were removed by vacuum distillation at 200 Pa and 150 °C for 2 hours to obtain trimethoxysilane-terminated polydimethylsiloxane (as shown in Formula 3, -X1-Y1- and -X2-Y2- are -CH2CH2SCH2CH2CH2-).

[0064] (2) 30 g of trimethoxysilane-terminated polydimethylsiloxane shown in Formula 3, 3.4 g of catechol (Formula 4, Ar is phenyl) and 25 g of absolute ethanol were added to a 250 ml three-necked flask. After dissolving and mixing evenly, 0.6 g of sodium methoxide (Formula 5, M is methyl, R' is sodium) was dissolved in 10 g of absolute ethanol and added dropwise to the three-necked flask. After the addition was completed, the reaction was carried out at 75 °C for 12 hours. Then 4.2 g of tetrabutylphosphonium chloride (Formula 7, R1, R2, R3 and R4 are all butyl, X is phosphorus) was dissolved in 20 g of absolute ethanol and slowly added dropwise to the three-necked flask. After the addition was completed, the reaction was continued for 5 hours. The reaction product was washed three times with 150 g of absolute ethanol and dried in vacuo at 100 °C for 12 hours to obtain 27 g of polydimethylsiloxane promoter C3 capped with phosphonium silicate ions.

[0065] The polydimethylphenylsiloxane promoter C3 capped with phosphonium silicate ions prepared in this example is as shown in Formula I, where R1, R2, R3 and R4 are all butyl, Ar is phenyl, A is -Si(CH3)2O-, -X1-Y1- and -X2-Y2- are -CH2CH2SCH2CH2CH2-, and n is 40.

[0066] Example 4. Synthesis of Promoter C4

[0067] (1) 24 g of vinyl-terminated polydimethylphenylsiloxane (as shown in Formula 1, A is -Si(CH3)(Ph)O-, n is 4), 40 g of trimethoxysilane (as shown in Formula 2, R7 is methyl, X' is hydrogen atom), 50 g of toluene and 0.014 g of chloroplatinic acid catalyst were added to a 250 ml three-necked flask under nitrogen protection. After stirring evenly at room temperature, the temperature was slowly raised to 70 °C and reacted for 10 hours. After the reaction was completed, toluene and unreacted trimethoxysilane were removed by vacuum distillation at 200 Pa and 100 °C for 2 hours to obtain trimethoxysilane-terminated polydimethylphenylsiloxane (as shown in Formula 3, -X1-Y1- and -X2-Y2- are both -CH2CH2-).

[0068] (2) Add 25 g of trimethoxysilane-capped polymethylphenylsiloxane shown in Formula 3, 19.2 g of 2,3-dihydroxynaphthalene (Formula 4, Ar is naphthyl), and 25 g of absolute ethanol into a 250 ml three-necked flask. After dissolving and mixing evenly, dissolve 0.8 g of sodium methoxide (Formula 5, M is methyl, R' is sodium) in 10 g of absolute ethanol and add it dropwise into the three-necked flask. After the dropwise addition, react at 75 °C for 12 hours. Then dissolve 22 g of tetraphenylphosphonium bromide (Formula 7, R1, R2, R3, and R4 are all phenyl, X is bromine) in 80 g of absolute ethanol, slowly add it dropwise into the three-necked flask, and continue to react for 4 hours after the dropwise addition. Wash the reaction product three times with 150 g of absolute ethanol, and vacuum dry at 100 °C for 12 hours to obtain 45 g of phosphonium silicate ion-capped polymethylphenylsiloxane promoter C4.

[0069] The phosphonium silicate ion-capped polymethylphenylsiloxane promoter C1 prepared in this example is shown in Formula I, where R1, R2, R3, and R4 are all phenyl, Ar is naphthyl, A is -Si(CH3)(Ph)O-, -X1-Y1- and -X2-Y2- are -CH2CH2-, and n is 4.

[0070] Example 5. Synthesis of Promoter C5

[0071] (1) Add 55 g of vinyl-capped polymethylphenylsiloxane (shown in Formula 1, A is -Si(CH3)(Ph)O-, n is 120), 20 g of trimethoxysilane (shown in Formula 2, R7 is methyl, X' is hydrogen atom), 50 g of toluene, and 0.004 g of chloroplatinic acid catalyst into a 250 ml three-necked flask under nitrogen protection. After stirring evenly at room temperature, slowly heat up to 70 °C and react for 10 hours. After the reaction is completed, distill under reduced pressure at 200 Pa and 100 °C for 2 hours to remove toluene and unreacted trimethoxysilane to obtain trimethoxysilane-capped polymethylphenylsiloxane (shown in Formula 3, -X1-Y1- and -X2-Y2- are both -CH2CH2-).

[0072] (2) Add 25 g of trimethoxysilane-capped polymethylphenylsiloxane shown in Formula 3, 2.4 g of 2,3-dihydroxynaphthalene (Formula 4, Ar is naphthyl), and 25 g of absolute ethanol into a 250 ml three-necked flask. After dissolving and mixing evenly, dissolve 0.8 g of sodium methoxide (Formula 5, M is methyl, R' is sodium) in 10 g of absolute ethanol and add it dropwise into the three-necked flask. After the dropwise addition, react at 75 °C for 12 hours. Then dissolve 2.5 g of tetraphenylphosphonium bromide (Formula 7, R1, R2, R3, and R4 are all phenyl, X is bromine) in 12 g of absolute ethanol, slowly add it dropwise into the three-necked flask, and continue to react for 4 hours after the dropwise addition. Wash the reaction product three times with 150 g of absolute ethanol, and vacuum dry at 100 °C for 12 hours to obtain 23 g of phosphonium silicate ion-capped polymethylphenylsiloxane promoter C4.

[0073] The silicate phosphonium ion-terminated polymethylphenylsiloxane accelerator C1 prepared in this example is shown in Formula I, where R1, R2, R3, and R4 are all phenyl groups, Ar is a naphthyl group, A is -Si(CH3)(Ph)O-, -X1-Y1- and -X2-Y2- are -CH2CH2-, and n is 120.

[0074] Examples 6-14, Preparation of Epoxy Resin Compositions (Using the Accelerator of the Present Invention)

[0075] First, each component in Table 1 was added to a high-speed mixer at room temperature and mixed evenly, then further fully melt-kneaded by a twin-screw extruder, extruded and cooled, and finally pulverized to obtain a powder of the epoxy resin mixture.

[0076] Comparative Examples 1-3, Preparation of Epoxy Resin Compositions (Using Existing Accelerators and Stress Modifiers)

[0077] First, each component in Table 1 was added to a high-speed mixer at room temperature and mixed evenly, then further fully melt-kneaded by a twin-screw extruder, extruded and cooled, and finally pulverized to obtain a powder of the epoxy resin mixture.

[0078] The components in Table 1 are as follows:

[0079] (1) Epoxy Resin

[0080] Epoxy Resin 1: o-Cresol Novolac Epoxy Resin (Jinan Shengquan Group, SQCN700)

[0081] Epoxy Resin 2: Biphenyl-Type Epoxy Resin (Jinan Shengquan Group, SQE-102)

[0082] Epoxy Resin 3: Trihydroxyphenylmethane-Type Epoxy Resin (Jinan Shengquan Group, SQTN-333)

[0083] (2) Curing Agent

[0084] Curing Agent 1: Linear Phenol Formaldehyde Resin (Jinan Shengquan Group, PF8010)

[0085] Curing Agent 2: Triphenolylmethane-Type Phenolic Resin (Jinan Shengquan Group, SH-6120)

[0086] (3) Curing Accelerator

[0087] Accelerator 1: Triphenylphosphine TPP (Sinopharm Reagent)

[0088] Accelerator 2: Triphenylphosphine-Benzoquinone Adduct TPP-BQ (Shanghai Titan Technology)

[0089] (4) Inorganic Filler

[0090] Fused spherical silica (Ronson Corporation, TFC-24)

[0091] (5) Stress modifier

[0092] Stress absorber 1: Carboxyl-terminated nitrile rubber (CVC Company, 1300X13)

[0093] Stress absorber 2: Epoxy-modified silicone oil (Dow Chemical, FZ-3730)

[0094] (6) Release agent

[0095] Polyethylene wax (Clariant, PE 130)

[0096] (7) Ion scavenger

[0097] Hydrotalcite (Kyowa Chemical Industry Co., Ltd., DHT-4A)

[0098] The present invention tested the properties of the epoxy resin compositions prepared in Examples 6-14 and Comparative Examples 1-3, and the test results are shown in Table 1. The test process is as follows:

[0099] Test conditions: Using a transfer molding machine, carried out under the conditions of a mold temperature of 175 °C, a molding pressure of 5 MPa, and a curing time of 120 s. The post-curing conditions are 175 °C for 5 hours.

[0100] (1) Gel time: Determine the gelation time (s) according to Article 5.3 of SJ / T 11197-2013 Epoxy molding compounds;

[0101] (2) Spiral flow length: Determine the flow distance (cm) according to Article 5.2 of SJ / T 11197-2013 Epoxy molding compounds;

[0102] (3) Flow retention: The epoxy resin composition is stored at 25 °C for 7 days, and then the flow length is tested by the method in (2) above and the flow length retention rate is calculated, that is, the percentage of the flow length of the resin after 7 days to the initial flow length;

[0103] (4) Warpage: The sample is encapsulated by a 175 °C transfer molding process on a 155×50 mm copper substrate, post-cured at 175 °C for 4 hours after demolding, and the warpage of the encapsulated sample is tested using a Shadow Morrie device. When the test value is positive, the warpage is a smiling face, and when the test value is negative, the warpage is a crying face;

[0104] (5) Glass transition temperature (T g ) : Determine T g ;

[0105] (6) Flexural properties: The flexural strength and flexural modulus are determined according to Article 5.5 of SJ / T 11197-2013 Epoxy Molding Compounds;

[0106] (7) Encapsulation reliability: Fifty 208-pin QFP packages (size 28 mm × 28 mm × 2.4 mm) are completed, and then the HAST reliability test is carried out with reference to IEC68-2-66 (temperature 120 °C, humidity 85%, time 192 hours). Record the number of failed encapsulated devices and calculate the defective rate, that is, the percentage of the number of failures to the number of tests.

[0107] Table 1 Comparison of the composition and properties of the examples and comparative examples

[0108]

[0109] From the comparison of the performance test results of Examples 6-12 and Comparative Examples 1-3 in Table 1, it can be seen that the epoxy resin composition prepared with the linear polymer promoter capped with phosphonium silicate ions of the present invention has an appropriate gel time, a longer spiral flow length and better flow retention. Its cured product has higher mechanical strength and glass transition temperature, and the encapsulated device has lower curing warpage and higher encapsulation reliability, showing significant superiority compared with the prior art; from the comparison of the performance test results of Example 6 and Examples 13-14 in Table 1, it can be seen that when n in Formula I is less than 5, the curing warpage and encapsulation reliability of the epoxy resin composition are poor, while when n is greater than 100, the gel time of the epoxy resin composition is prolonged, and the curing property and mechanical strength are reduced, thus affecting the encapsulation reliability.

Claims

1. A phosphonium silicate ion-capped linear polymer promoter, the structural formula of which is shown in Formula I below: In Formula I, A is one or several copolymerized repeating units selected from -Si(CH3)2O-, -Si(CH3)(Ph)O-, -Si(Ph)2O-, -CH2CH2O-, -CH(CH3)CH2O- and -CH2CH2CH2CH2O-; n is an integer greater than 2; Ar is selected from aromatic groups; R1, R2, R3 and R4 are independently selected from phenyl, benzyl or C1-C6 alkyl; -X1-Y1- and -X2-Y2- are each an organic group selected from those linking the silicon atom in the phosphonium silicate ion and the molecular chain -(A) n - and they may be the same or different from each other.

2. The linear polymer promoter according to claim 1, characterized in that: In Formula I, n is an integer from 5 to 100; Ar is selected from phenyl, naphthyl, biphenyl and binaphthyl; -X1-Y1- and -X2-Y2- are organic groups formed by thiol-ene click reaction or hydrosilylation reaction and containing -S-CH2-CH2- or -CH2-CH2- units.

3. A method for preparing the linear polymer promoter according to claim 1 or 2, comprising the following steps: (1) React the vinyl-capped polymer shown in Formula 1 with the functional group-containing trialkoxysilane shown in Formula 2 to obtain a trialkoxysilane-capped polymer intermediate shown in Formula 3; In each formula, A is a repeating unit copolymerized from one or more of -Si(CH3)2O-, -Si(CH3)(Ph)O-, -Si(Ph)2O-, -CH2CH2O-, -CH(CH3)CH2O- and -CH2CH2CH2CH2O-; n is an integer greater than 2; Y1 and Y2 are each an alkyl group having 1 to 6 carbon atoms; R7 is an alkyl group having 1 to 3 carbon atoms, X' is a hydrogen atom or 3-mercaptopropyl; -X1-Y1- and -X2-Y2- are each an organic group selected from those connecting a silicon atom and the molecular chain -(A) n -, and the two may be the same or different; X1 and X2 are organic groups formed after the addition of the capped double bond in Formula 1 and X' in Formula 2; (2) React the trialkoxysilane-capped polymer intermediate shown in Formula 3, the proton donor containing an aromatic ring structure shown in Formula 4 and the alkali metal alkoxide shown in Formula 5 to obtain a silicate-capped polymer intermediate shown in Formula 6; In each formula, Ar is selected from aromatic groups; M represents lithium, sodium or potassium; R' is C1-C3 alkyl; The definitions of -X1-Y1-, -X2-Y2- and A are the same as those in Formula 3; (3) React the silicate-capped polymer intermediate shown in Formula 6 with the phosphonium halide compound shown in Formula 7 to obtain the phosphonium silicate ion-capped linear polymer promoter according to claim 1 or 2; In Formula 7, R1, R2, R3 and R4 are independently selected from phenyl, benzyl or C1-C6 alkyl, and X is chlorine or bromine.

4. The preparation method according to claim 3, characterized in that: In Formula 4, Ar is selected from phenyl, naphthyl, biphenyl and binaphthyl; n is an integer from 5 to 100; -X1-Y1- and -X2-Y2- are organic groups formed by thiol-ene click reaction or hydrosilylation reaction and containing -S-CH2-CH2- or -CH2-CH2- units.

5. An epoxy resin composition, comprising the following components (A)-(C) or components (A)-(D): (A) An epoxy resin compound having at least 2 epoxy groups in its molecular structure; (B) A phenolic resin compound having at least 2 phenolic hydroxyl groups in its molecular structure; (C) The phosphonium silicate ion-capped linear polymer promoter according to claim 1 or 2; (D) Inorganic filler.

6. The epoxy resin composition according to claim 5, wherein: The epoxy resin compound is selected from at least one of glycidyl ether type epoxy resins, glycidyl amine type epoxy resins, glycidyl ester type epoxy resins and alicyclic epoxy resins; The phenolic resin compound is selected from at least one of linear phenolic resins, phenol aralkyl resins, bisphenol and polyphenol monomers, and poly(p-hydroxystyrene).

7. The epoxy resin composition according to claim 5 or 6, characterized in that: The inorganic filler is selected from at least one of silica, alumina, silicon carbide, titanium dioxide, aluminum nitride, boron nitride, aluminum hydroxide, calcium carbonate, barium sulfate, wollastonite, clay, and glass fiber.

8. The epoxy resin composition according to claim 5 or 6, characterized in that: In the epoxy resin composition, the mass percentage content of the linear polymer accelerator capped with phosphonium silicate ions is 1-25%.

9. Application of the epoxy resin composition according to any one of claims 5-8 as an encapsulating plastic in encapsulating semiconductor devices.

10. A semiconductor device, which includes an electronic component encapsulated with the epoxy resin composition according to any one of claims 5-8 as an encapsulating plastic.

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