CN101348568B - Accurate structure POSS hybridization low dielectric material preparation - Google Patents

Abstract

The invention relates to a method for preparing a precise structure POSS hybrid low dielectric material, which uses a POSS monomer containing an active group and a bifunctional organic small molecule capable of click chemical reaction as a precise structure hybrid low dielectric material The precursor prepared by the material uses an environmentally friendly click chemical synthesis method to orderly connect POSS molecules and small organic molecules with precise structures into the structure of low-dielectric materials. By changing the composition, structure and structure of organic molecular chains connected to POSS Performance, realize the control of the structure, porosity, thermal properties, mechanical properties and dielectric constant of the precise structure hybrid low dielectric material.

Description

Preparation method of POSS hybrid low dielectric material with precise structure

technical field

The invention belongs to the field of preparation of low-dielectric materials, in particular to a method for preparing POSS hybrid low-dielectric materials with precise structure. the

Background technique

With the rapid development of circuits, devices and components, especially the emergence of high-density integrated circuits in recent years, the requirements for electronic packaging materials are also getting higher and higher. Electronic packaging materials are an important support for electronic packaging technology. For integrated circuit packaging, electronic packaging materials refer to the sealing body of integrated circuits. Encapsulation not only has mechanical support and environmental protection for the chip, but also prevents it from being polluted and eroded by water vapor, impurities and various chemical atmospheres in the atmosphere, so that the integrated circuit chip can stably perform normal electrical functions, and the encapsulation is important for devices and The thermal performance and even the reliability of the circuit play a pivotal role. Electronic packaging materials mainly include plastic packaging materials, ceramic packaging materials and metal packaging materials. Due to the poor processing performance of the latter two, it is difficult to meet the rapidly developing electronic packaging technology, and its application is limited to the hermetic packaging in aerospace, aviation and military fields. It is widely used in civilian fields because of its light weight and excellent performance. The current electronic packaging technology requires plastic packaging materials to have the following properties: high thermal stability, good mechanical properties, excellent dielectric properties, good flame retardancy, high radio frequency stability, good processing performance, low water absorption, coefficient of thermal expansion (CTE) low and high thermal conductivity. the

Molding compounds are generally composed of matrix resin, fillers and additives. The matrix resin is an important component of the molding compound, which plays the role of bonding, insulation and endowing the material with excellent processing and molding properties. At present, there are mainly: epoxy resin (ER), silicone (silicone plastic), polyimide (PI) and polyphenylene sulfide (PPS). the

CN200510021278.8 discloses a polyphenylene sulfide electronic packaging material, which contains high-purity polyphenylene sulfide resin, inorganic filler surface-treated with a coupling agent, a toughening agent and a leveling modifier. CN200710027674.0 discloses a composite epoxy-type electronic packaging material and a preparation method thereof. The obtained composite epoxy-type electronic packaging material has the advantages of high heat resistance, low water absorption and good environmental protection and flame retardancy. CN200410026436.4 discloses a silicone-modified epoxy resin and its preparation method, an electronic packaging material made from it and the preparation method of the electronic packaging material, and an electronic packaging epoxy resin material with better performance is obtained. CN01103521.8 discloses a synthesis technology of a low dielectric constant soluble polyarylether, which has a lower dielectric constant (2.7-2.8) and better solubility. CN200410083960.5 discloses a method for preparing a low dielectric constant nanoporous polyimide film. The polyimide/nano-silicon dioxide composite film is prepared by a sol-gel method, and the composite film is soaked in an etching solution, and then washed and dried to prepare a polyimide nano-foaming film. 02807986.8 discloses a low dielectric constant organic dielectric based on a cage structure, which has a first main chain with an aromatic moiety and a first reactive group, and an aromatic moiety and a second reactive group wherein the first and second main chains are cross-linked by the first and second reactive groups in the cross-linking reaction without additional cross-linking agent, and wherein the cage structure containing at least 10 atoms is co- Valence is bound to at least one of the first and second backbones. the

With the upgrading of electronic packaging materials and technologies, people pay more attention to its non-toxic, green and environment-friendly characteristics while pursuing high performance of products. There are many proposals and regulations to restrict and prohibit the use of certain materials in the electronics industry that are detrimental to the environment and health. The matrix resin is the main part of electronic packaging materials. Therefore, the synthesis of new low-dielectric resins with toughening, thermal conductivity, heat resistance, hydrophobicity and flame retardancy is the key to the development of non-toxic, green and environmentally friendly electronic packaging materials. . the

Polyhedral oligomeric silsesquioxane (Polyhedral oligomeric silsesquioxane, referred to as POSS) molecular size is about 1 ~ 3nm, its cage structure is similar to silicon dioxide (Si: O = 1: 1.5), and has a pore size of about 0.5 nm intrinsic microporous structure. POSS molecules have stable thermodynamic properties, low density and excellent mechanical properties. The eight (or ten, or twelve) vertices of its cage structure can be bonded to different organic functional groups to become POSS organic functional monomers. It is a class of multifunctional organic/inorganic hybrid molecules that can be grafted on The side chains of polymers or directly enter the main chain and cross-linked network to prepare copolymerized or cross-linked hybrid polymers. In addition, POSS itself has good flame retardancy, whether it is connected to the side chain or main chain of the polymer, or directly enters the cross-linked network, due to the nano-size effect (the size of the molecule is about 1-3nm), it can It hinders the movement of molecular segments and improves the thermodynamic stability of hybrid polymers. And the multifaceted microporous _SiO2 in the POSS molecule has a rigid structure, which can effectively reduce the thermal expansion coefficient of the material and improve the thermal conductivity.

CN200710110427.7 discloses a low-dielectric resin containing oligomeric silsesquioxane and a preparation method thereof. The resin is mixed with silsesquioxane compound containing reactive functional groups, bismaleimide, cyanate, and/or epoxy resin, allyl compound and other thermosetting resins by melting or solution method, Prepared by prepolymerization. The cured resin has a lower dielectric constant and better heat resistance. However, it is difficult to precisely control the structure of the material prepared by this method, which will lead to the instability of the material performance. the

Contents of the invention

The purpose of the present invention is to provide a preparation method of POSS hybrid low dielectric material with precise structure, which is based on the precise structure hybridization of POSS monomers containing active groups and bifunctional organic small molecules that can undergo click chemical reactions The precursors prepared by low dielectric materials use the environment-friendly click chemical synthesis method to orderly connect POSS molecules and small organic molecules with precise structures into the structure of low dielectric materials. the

The preparation method of the precise structure POSS hybrid low dielectric material of the present invention comprises steps:

In the solution system, in the presence of a photoinitiator or catalyst, POSS reacts with a bifunctional organic precursor under light or heating (20-60°C) for 0.5-10h to generate a precise structure POSS hybrid low-dielectric material , wherein the mass ratio of SiO _1.5 in POSS to the bifunctional organic precursor is 5-80:90-20, preferably 20-60:80-40.

The solvent of the solution system is one of water, methanol, ethanol, cyclohexane, benzene, toluene, xylene, dioxane, tetrahydrofuran, dimethylformamide, dimethyl sulfoxide, and methylene chloride Or several, its mass ratio to the precursor POSS is in the range of 100-2:1. the

The catalyst is necessary for click chemistry to occur, such as benzoin dimethyl ether, CuSO ₄ ·5H ₂ O or CdCl ₂ .

The POSS is an oligomeric silsesquioxane containing active groups, the general formula can be expressed as R _x R' _y (SiO _1.5 )n, wherein n is 8, 10, or 12, 2≤x≤n, x+ y=n; wherein R is an active group capable of click chemical reaction including alkenyl, mercapto, azide, alkynyl, amine, epoxy or -OSiR ₁ R ₂ R ₃ (wherein R ₁ and R ₂ can be Simultaneously or independently hydrogen atom, halogen atom, hydroxyl, C _1-20 alkyl, alkenyl, aryl, alicyclic, alkoxy, wherein _R3 must be alkenyl, mercapto, azide, alkynyl , amino group, epoxy group), etc.; R' can be a hydrogen atom, a halogen atom, a hydroxyl group, a C _1-20 alkyl group, an alkenyl group, an alkynyl group, an aryl group, an alicyclic group, an alkoxy group , or -OSiR ₁ R ₂ R ₃ (where R ₁ , R ₂ , and R ₃ are simultaneously or independently hydrogen atom, halogen atom, hydroxyl, C _1-20 alkyl, alkenyl, alkynyl, aryl, aliphatic Cyclic, alkoxy) etc.

The general formula of the bifunctional organic precursor is R'-R-R', wherein R' is a functional group at both ends including alkenyl, mercapto, azide, alkynyl, amine, epoxy, etc., and R can be C _1-20 Alkyl, alkenyl, alkynyl, aryl, alicyclic, alkoxy, urethane, hydroxyl, carbonyl, amide, etc. are organic segments combined by chemical bonds.

In the POSS hybrid low-dielectric material with precise structure, the dielectric constant is lower than 2.7, the POSS is uniformly and orderly connected in the low-dielectric hybrid material, the coefficient of thermal expansion is 60-120 μm/m°C, and it has good hydrophobicity. the

Beneficial effect:

(1) The click chemical reaction adopted has mild reaction conditions, is environmentally friendly, highly efficient and controllable, and is insensitive to water and oxygen, such as the addition reaction of ethylenic bonds and sulfhydryl groups under the action of trace photoinitiators through light ;

(2) Using carbon heteroatom bonding reaction to quickly connect POSS to hybrid material molecules uniformly and orderly;

(3) By changing the composition, structure and performance of the organic molecular chains connected to POSS, the regulation of the structure, porosity, thermal properties, mechanical properties and dielectric constant of the precise structure hybrid low dielectric material is realized, and the prepared low dielectric The materials are mainly used in electronic packaging materials, low dielectric coatings and other fields. the

Detailed ways

Below in conjunction with specific embodiment, further illustrate the present invention. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the teachings of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of the present application. the

Example 1

Synthesis of double-arm vinyl POSS: (1) Preparation of double-arm vinyl POSS intermediate: 120g of trimethoxyphenylsilane, 16g of NaOH and 10-20g of H ₂ O were placed in a 1000mL funnel equipped with a constant pressure , the condensing reflux tube and the four-necked flask of the thermometer, then add 2-propanol (the mass ratio of the reaction substance to 2-propanol is 1:4 to 1:40) to dissolve the above-mentioned substances, and under the protection of nitrogen, magnetically stir and heat to reflux 4h, stop heating, let the reaction mixture stand at room temperature for 8h, filter, wash with 2-propanol, and dry in vacuo to obtain a white solid a; (2) mix 22.60g (0.02mol) of solid a with 8.00g (0.08mol) of triethyl The amine was placed in a four-necked flask equipped with a condensing reflux tube, a constant pressure funnel, and a thermometer, and 200 to 300 mL of THF was added, magnetically stirred for 1 hour, and 8.40 g (0.06 mol) of methylvinyldichlorosilane, continue to stir for 2h, add 100-200mL of water to the reaction mixture, dissolve the generated sodium chloride and hydrolyzed unreacted methylvinyldichlorosilane, let stand to separate layer, the organic layer was washed successively with hydrochloric acid, saturated sodium bicarbonate solution and deionized water to obtain the product. The response is as follows:

Synthesis of bifunctional mercapto monomer: 9.21g (0.10mol) of thioglycolic acid, diamine monomer quality is respectively 10.01g, 14.62g and 20.51g (both 0.05mol) dissolved in benzene solvent (reaction substance and The mass ratio of benzene is 1:4～1:40), placed in a 150mL round-bottomed flask, heated to reflux at 110°C for 10h. A solid product was obtained, which was purified by recrystallization from ethanol. Product number: M ₁ ~ M ₃ , the synthesis steps are as follows:

Two-arm vinyl POSS: bifunctional mercapto monomer = 1:1 molar ratio, that is, 24.44g (0.02mol) of the above-mentioned vinyl POSS and 6.97g (0.02mol) M ₁ , 8.57g (0.02mol) M ₂ , 11.17g (0.02mol) _M3 and a trace amount of benzoin dimethyl ether are dissolved in tetrahydrofuran (the mass ratio of reaction substance to THF is 1:5～1:100), and added to a 250mL round bottom flask equipped with a stirrer , under light conditions, react for 2 to 10 hours, click chemical reaction occurs, and the reaction is as follows. A linear POSS hybrid low-dielectric material with a precise structure is obtained, and the length of the organic segment is adjusted. Its dielectric constant (test frequency 1M) is 2.25-2.03, and it has a low thermal expansion coefficient of 83-91 μm/m°C.

Example 2

Synthesis of mercapto POSS: 196.30g (1.0mol) of γ-mercaptopropyltrimethoxysilane, 800mL of methanol, 55mL of distilled water and an appropriate amount of concentrated hydrochloric acid are used to adjust the pH value to 3.0, and then added to the In a 1500mL three-neck flask, under the protection of nitrogen, the reaction was carried out at a constant temperature of 60°C for 48h. Then stop heating and cool to room temperature, filter the product precipitated by the reaction, and wash the product with cyclohexane.

Synthesis of diene monomer: Take a 1000mL flask, add 20.00g (0.144mol) p-hydroxybenzoic acid, then pour 300mL ethanol and 200mL water. Also known as 10g NaOH and 2g KI, dissolved in 100mLH ₂ O, NaOH, KI solution was added dropwise to the ethanol-water solution, after about 1~2h, add 13mL (0.153mol, excess) bromopropene, 65~70 ℃ reflux 70h. Stop the reaction, add 30mL of concentrated hydrochloric acid to acidify, rotary evaporate, obtain a large amount of white precipitate, filter with suction, collect the solid, and recrystallize from ethanol to obtain white needle-like crystals. Weigh 4.00g (0.024mol) of p-allyloxybenzoic acid in a 150mL three-necked flask, add 60mL of anhydrous toluene to dissolve, add 6mL (0.11mol, excess) of thionyl chloride, and connect the condenser tube to a _CaCl2 drying tube, The reaction was stirred at 60°C for 4h. Excessive SOCl ₂ and solvent toluene were distilled off under reduced pressure to obtain a pale yellow liquid. Following the reaction of the synthesis of acid chlorides in the previous step, add 60 mL of THF, 0.62 mL (0.011 mol) of ethylene glycol (or 1.0 mL of butanediol, 0.011 mol) into a three-necked flask, and add 8 mL of triethylamine as an acid-binding agent. Reflux reaction for 24h. The reaction solution was concentrated by rotary evaporation and passed through a neutral alumina chromatographic column. The eluent uses the ratio of petroleum ether: ethyl acetate = 1:1 to collect the front fluorescent point components. Rotary evaporation gave a pale yellow solid, which was recrystallized with a small amount of ethanol to give needle-like crystals. Diene monomer product number: M ₁ ~ M ₄ (n=2, 4, 6, 8), the synthesis steps are as follows:

According to the molar ratio of thiol POSS:diene = 1:4, 10.18g (0.01mol) of the above-mentioned mercapto POSS were mixed with 15.29g (0.04mol) M ₁ , 16.41g (0.04mol) M ₂ , 17.53g (0.04mol) M ₃ , 18.65g (0.04mol) M ₄ and a trace amount of benzoin dimethyl ether are dissolved in tetrahydrofuran (the mass ratio of reaction substance to THF is 1:4~1:80), and added to a 250mL round bottom equipped with a stirrer In the flask, under light conditions, react for 2-10 hours, click chemical reaction occurs, and the reaction is as follows. A network-type POSS hybrid low-dielectric material with a precise structure is obtained, and the length of the organic segment is adjusted. Its dielectric constant (test frequency 1M) is 2.35-2.11, and it has a low thermal expansion coefficient of 65-84 μm/m°C.

Example 3

The synthesis of two-arm azido-based POSS, its synthetic method is divided into 3 steps, (1) is identical with the synthetic step (1) of double-arm vinyl POSS in embodiment 1; (2) only double-arm vinyl in embodiment 1 The methylvinyldichlorosilane in the synthetic step (2) of the base POSS is replaced by 3-propylmethyldichlorosilane of 11.40g (0.06mol); (3) the substance of 26.44g (0.02mol) b was dissolved in 150mL of THF, then added 20mL of aqueous solution dissolved with 3.90g (0.06mol) NaN ₃ , stirred at room temperature for 2-6h, and purified to obtain the double-armed azido POSS. The response is as follows:

Synthesis of bifunctional alkyne monomer: put 8.00g (0.10mol) of acetylenic acid and 23.80g (0.20mol) of thionyl chloride in a 250mL round-bottomed flask with a condenser, heat and stir, and react at 65°C for 4h , the excess SOCl ₂ was distilled off under reduced pressure, and then dissolved in dichloromethane (the mass ratio of diamine monomer to dichloromethane was 1:5 to 1:40) with a mass of 10.01g, 14.62g and 20.51g ( Both are 0.05mol) diamine monomers were added therein, heated to reflux for 3h. A solid product was obtained, which was purified by recrystallization from ethanol. Product number: M ₁ ~ M ₃ , the synthesis steps are as follows:

Two-arm azido-based POSS: bifunctional alkyne monomer = 1:1 molar ratio, that is, 25.60g (0.02mol) of the above-mentioned two-arm azido-based POSS and 6.97g (0.02mol) M ₁ , 8.57g (0.02 mol)M ₂ , 11.17g (0.02mol)M ₃ and an appropriate amount of CuSO ₄ 5H ₂ O were dissolved in water/tetrahydrofuran solvent (the mixing ratio was 1:50, and the mass ratio of reaction substance to THF was 1:2～1: 50), put it into a 250mL round-bottomed flask, and react for 2-10 hours under stirring at room temperature, and a click chemical reaction occurs, and the reaction is as follows. Obtain a straight-chain POSS hybrid low-dielectric material containing 1,3,5-triazole with a precise structure, adjust the length of the organic chain segment, and its dielectric constant (test frequency 1M) is 2.58-1.96, with low thermal expansion The coefficient is 76～85μm/m℃.

Example 4

Synthesis of dual-arm epoxy-containing functional POSS: The vinyl in the dual-arm vinyl POSS synthesized in Example 1 was oxidized by m-chloroperoxybenzoic acid to obtain dual-arm epoxy-containing functional POSS, specifically as follows. 12.44g (0.01mol) of double-armed vinyl POSS and 10.12g (0.04mol) of m-chloroperoxybenzoic acid (m-CPBA) were added to a 250mL three-necked flask, and then 150mL of dichloromethane was added, 40 ℃ reflux for 48h, and the reaction solution was placed at 0℃ overnight, and a white precipitate was precipitated, which was washed and recrystallized to obtain the functional POSS with epoxy groups in both arms. The response is as follows:

Two-arm epoxy-containing functional POSS: diamine monomer = 1:1 molar ratio, that is, 12.53g (0.01mol) of the above two-arm epoxy-containing functional POSS and the mass are 2.00g, 2.92g and 4.10g respectively (both 0.05mol) diamine monomers are dissolved in dichloromethane solvent (mass ratio of reaction substance to dichloromethane is 1:4~1:50), and an appropriate amount of CdCl ₂ is added to initiate a click chemical reaction. The reaction is as follows . A linear POSS hybrid low-dielectric material with precise structure is obtained, and the length of the flexible organic segment is adjusted. Its dielectric constant (test frequency 1M) is 2.41-2.18, and it has a low thermal expansion coefficient of 102-115 μm/m°C.

Claims (2)

1. the preparation method of an accurate structure POSS hybridization low dielectric material comprises step:

In solution system, and in the presence of the catalyzer of necessity, POSS and double-functional group organic precursor react 0.5～10h under illumination or 20～60 ℃ of heating conditions, generate accurate structure POSS hybridization low dielectric material; Wherein catalyzer is benzoin dimethylether, CuSO ₄5H ₂O or CdCl ₂

Described POSS contains the active group oligomeric silsesquioxane, is both arms vinyl POSS, and its general formula is expressed as R _xR ' _y(SiO _1.5) _n, wherein n is 8,10 or 12, x=2, x+y=n; Wherein R is vinyl, and R ' is hydrogen atom, halogen atom, hydroxyl, C _1-20Alkyl, alkenyl, alkynyl, aryl, alicyclic radical, alkoxyl group or-OSiR ₁R ₂R ₃, R wherein ₁, R ₂, R ₃Independent at the same time or separately is hydrogen atom, halogen atom, hydroxyl, C _1-20Alkyl, alkenyl, alkynyl, aryl, alicyclic radical, alkoxyl group;

Described double-functional group organic precursor is difunctional sulfydryl monomer, and its general formula is R '-R-R ', and wherein R ' is the functional group at two ends, and R ' is sulfydryl, and R is C _1-20Alkyl, alkenyl, alkynyl, aryl, alicyclic radical, amine ester group, carbonyl or acid amides are by organic segment of chemical bonding;

Both arms vinyl POSS wherein: the mol ratio of difunctional sulfydryl monomer=1:1.

2. the preparation method of accurate structure POSS hybridization low dielectric material according to claim 1, it is characterized in that: the solvent of described solution system is one or more in water, methyl alcohol, ethanol, hexanaphthene, benzene,toluene,xylene, dioxane, tetrahydrofuran (THF), dimethyl formamide, dimethyl sulfoxide (DMSO), the methylene dichloride, and the mass ratio of itself and presoma POSS is in 100～2:1 scope.