Preparation method and application of intrinsic cross-linked benzocyclobutene monomer containing unsaturated double bonds

Abstract

The present invention discloses a method for preparing an intrinsically cross-linked benzocyclobutene monomer containing unsaturated double bonds and its application. The structural formula thereof is shown in Formula I. The intrinsically cross-linked benzocyclobutene cured product containing unsaturated double bonds provided by the present invention has excellent dielectric properties ( D k <2.37, D f =1.87×10 ‑3 ), high thermal stability (T 5% >483°C), good mechanical properties (elastic modulus (5.3 GPa) and hardness (0.66 GPa)), and a reasonable coefficient of thermal expansion (CTE = 48 ppm / °C). The unsaturated double bonds in the intermediate bridging group increase the crosslinking density of the polymer, improving the overall performance of the material.

Description

Technical Field

[0001] The invention belongs to the field of electronic packaging, and in particular relates to a preparation method of an intrinsic cross-linked benzocyclobutene monomer containing an unsaturated double bond and an application thereof. Background Art

[0002] Benzocyclobutene-based resins are exceptional polymer materials, boasting excellent dielectric properties, good thermal stability, and exceptional chemical resistance. These remarkable properties have led to their widespread application as interlayer dielectric materials in fields such as microelectronics, optoelectronics, and flat-panel displays. BCB resins are also commonly used as encapsulation materials and crosslinking agents. The key to their exceptional performance lies in their unique structure and ring-opening crosslinking reactivity. The four-membered ring structure of benzocyclobutene undergoes ring opening upon heating, forming a highly reactive o-quinodimethane intermediate. This intermediate is capable of undergoing both intramolecular and intermolecular Diels-Alder reactions with various dienes. The Diels-Alder addition reaction forms a crosslinked network within the benzocyclobutene-based resin monomer, enhancing the overall strength and stiffness of the polymer. Furthermore, the anchoring of the molecular chains makes the polymer less susceptible to thermal decomposition and oxidation, improving its thermal stability. This crosslinking reaction effectively limits the segmental mobility of the polymer chains, preventing them from aligning along the external electric field, thereby reducing the dielectric constant. Summary of the Invention

[0003] One of the purposes of the present invention is to provide an intrinsically cross-linked benzocyclobutene monomer containing an unsaturated double bond and a preparation method thereof.

[0004] In a first aspect of the present invention, there is provided an intrinsically cross-linked benzocyclobutene monomer containing an unsaturated double bond, the structural formula of which is shown in Formula I:

[0005]

[0006] In formula I, R is selected from or .

[0007] The present invention also provides a method for preparing the intrinsic cross-linked benzocyclobutene monomer containing unsaturated double bonds.

[0008] The present invention provides a method for preparing an intrinsically cross-linked benzocyclobutene monomer containing an unsaturated double bond. The method comprises using 1,4-dibromo-2,5-dimethylbenzene as a raw material, sequentially subjecting the monomer to bromination, Grignard reaction, and Suzuki reaction to obtain an intrinsically cross-linked benzocyclobutene monomer containing an unsaturated double bond. The structural formula of the monomer is shown in Formula I-a, and the reaction equation is:

[0009]

[0010] Alternatively, 1,4-dichloro-2,5-dibromobenzene is used as a raw material, and a catalytic aromatic norbornene cyclization reaction (CNANL reaction) and a Suzuki reaction are sequentially performed to obtain an intrinsic cross-linked benzocyclobutene monomer containing an unsaturated double bond, the structural formula of which is shown in Formula I-b, and the reaction equation is:

[0011]

[0012] By adopting the above technical solution, an intrinsic cross-linked benzocyclobutene monomer containing an unsaturated double bond is obtained, and the preparation method is simple and the synthesis method is novel.

[0013] Furthermore, the preparation method of the intrinsic cross-linked benzocyclobutene monomer containing unsaturated double bonds of the present invention comprises the following steps:

[0014] 1) 1,4-dibromo-2,5-dimethylbenzene is subjected to bromination reaction at high temperature to obtain a brominated product;

[0015] 2) In an inert atmosphere, the brominated product undergoes a Grignard reaction with an allyl Grignard reagent at low temperature to obtain a product with an allyl side group;

[0016] 3) In an inert atmosphere, the product having an allyl side group and 4-boronic acid benzocyclobutene or 4-boronic acid benzocyclobutene undergo a Suzuki reaction in the presence of a base and a catalyst to obtain the product of formula I-a;

[0017] or,

[0018] 1') In an inert atmosphere, 1,4-dichloro-2,5-dibromobenzene and norbornadiene undergo a catalytic aromatic norbornene cyclization reaction (CNANL reaction) to obtain a CANAL reaction product;

[0019] 2') In an inert atmosphere, the CANAL reaction product and 4-boronic acid benzocyclobutene or 4-boronic acid benzocyclobutene undergo a Suzuki reaction in the presence of a base and a catalyst to obtain the product of formula I-b.

[0020] Furthermore, the preparation method of the intrinsic cross-linked benzocyclobutene monomer containing unsaturated double bonds of the present invention comprises the following steps:

[0021] 1) 1,4-dibromo-2,5-dimethylbenzene and N-bromosuccinimide or liquid bromine react in an oil bath for a certain period of time under the action of a free radical initiator to obtain a brominated product;

[0022] 2) In an inert atmosphere, the brominated product and catalyst are added to an organic solvent, and the solvent temperature is lowered to -78°C. A vinyl Grignard reagent is added to the reaction system and the reaction is continued at -78°C. After the reaction is complete, the solvent is added to quench the Grignard reaction, yielding a product with an allyl pendant group.

[0023] 3) In an inert atmosphere, the Grignard reaction product is reacted with 4-boronic acid benzocyclobutene or 4-boronic acid benzocyclobutene in the presence of a base and a catalyst in a high-temperature oil bath for several hours to allow the Suzuki reaction to proceed smoothly, thereby obtaining the product of Formula I-a;

[0024] or

[0025] 1') In an inert atmosphere, 1,4-dichloro-2,5-dibromobenzene and norbornadiene are added to an organic solvent, and reacted at a high temperature of 100-150° C. in the presence of a base, a catalyst, and a ligand to perform a CANAL reaction to obtain a CANAL reaction product;

[0026] 2') In an inert atmosphere, the CANAL product and 4-boronic acid benzocyclobutene or 4-boronic acid benzocyclobutene are added to an organic solvent and reacted in a high-temperature oil bath in the presence of a base, a catalyst, and a ligand for several hours to facilitate the Suzuki reaction, yielding the product of Formula I-b.

[0027] In step 1) of the above method, the molar ratio of 1,4-dibromo-2,5-dimethylbenzene to N-bromosuccinimide may be 1:(2-4);

[0028] The reaction is carried out in a first solvent, wherein the first solvent is at least one of acetonitrile, benzene, titanium tetrachloride, N,N-dimethylformamide or toluene;

[0029] The free radical initiator is at least one of azobisisobutyronitrile or azobisisoheptanenitrile;

[0030] The temperature of the oil bath can be 100-110°C, and the reaction time can be 18-24 hours;

[0031] In step 2), the molar ratio of the brominated product to the catalyst may be 1:(1-2);

[0032] The catalyst may be at least one of cuprous iodide or ferrous chloride;

[0033] The vinyl grignard reagent can specifically be vinyl magnesium bromide,

[0034] The molar ratio of the brominated product to the vinyl Grignard reagent can be 1:4;

[0035] The reaction is carried out in a second solvent, wherein the second solvent is at least one of dichloromethane and acetone;

[0036] The vinyl grignard reagent is added and the reaction time can be 3-5 hours;

[0037] The solvent used to quench the Grignard reaction in step 2) is at least one of hydrochloric acid, glacial acetic acid, water, and ammonium chloride;

[0038] In step 3), the molar ratio of the Grignard reaction product to 4-boronic acid benzocyclobutene or 4-boronic acid benzocyclobutene can be 1:(2-2.5);

[0039] The catalyst may be at least one of triphenylphosphine palladium and palladium acetate;

[0040] The base may be at least one of sodium carbonate, potassium carbonate, sodium hydroxide and potassium hydroxide;

[0041] The reaction is carried out in a third solvent, which is at least one of 1,4-dioxane, toluene, dimethyl sulfoxide, and dimethyl ether, and a certain amount of water and ethanol;

[0042] The reaction temperature may be 100-120°C and the reaction time may be 12-24 h;

[0043] In step 1'), the molar ratio of 1,4-dichloro-2,5-dibromobenzene to norbornadiene may be 1:(2-2.5);

[0044] The base may be at least one of cesium carbonate, potassium carbonate or sodium carbonate;

[0045] The ligand may be at least one of triphenylphosphine or tricyclohexylphosphine;

[0046] The catalyst may be at least one of triphenylphosphine palladium and palladium acetate;

[0047] The reaction temperature may be 100-150°C and the reaction time may be 12-24 hours;

[0048] The reaction is carried out in a fourth solvent, wherein the fourth solvent is at least one of toluene and 1,4-dioxane;

[0049] In step 2'), the molar ratio of the CANAL product to 4-boronic acid benzocyclobutene or 4-boronic acid benzocyclobutene can be 1:(2-2.5);

[0050] The reaction is carried out in a third solvent, which is a mixed solution of at least one of 1,4-dioxane, toluene, dimethyl sulfoxide, dimethyl ether and tetrahydrofuran and water;

[0051] The base is at least one of cesium fluoride and potassium fluoride;

[0052] The catalyst is at least one of tris(dibenzylideneacetone)dipalladium and [1,1'-bis(di-tert-butylphosphino)ferrocene]palladium dichloride;

[0053] The ligand is at least one of tri-tert-butylphosphine or tri-tert-butylphosphine tetrafluoroborate;

[0054] The reaction temperature may be 80-100° C., and the reaction time may be 8-12 h.

[0055] A second object of the present invention is to provide an intrinsically cross-linked network benzocyclobutene resin having a regular network structure.

[0056] The intrinsically cross-linked benzocyclobutene resin with a regular network structure provided by the present invention is made of an intrinsically cross-linked benzocyclobutene monomer containing an unsaturated double bond as shown in Formula I.

[0057] Specifically, its structural formula is shown in Formula V-a or Formula V-b:

[0058]

[0059] The intrinsic cross-linked network benzocyclobutene resin represented by formula V-a or formula V-b is obtained by prepolymerizing the benzocyclobutene resin monomer represented by formula I-a or formula I-b in an organic solvent under the protection of an inert gas to obtain a prepolymer, and then heating and cross-linking and curing it, or directly heating and curing and cross-linking it.

[0060] Furthermore, the organic solvent is selected from at least one of toluene, o-xylene, 1,3,5-trimethylbenzene, N,N-dimethylformamide and N,N-dimethylacetamide;

[0061] The inert atmosphere for protection is selected from at least one of nitrogen and argon;

[0062] The prepolymerization temperature can be 150-180°C, and the time can be 12-36 hours, specifically, the prepolymerization can be heated and stirred at 160°C for 24 hours;

[0063] The temperature rise process of the heating cross-linking curing is 150° C. curing for 1 hour, 200° C. curing for 1 hour, 235° C. curing for 1 hour, 260° C. curing for 3 hours, and 300° C. curing for 1 hour.

[0064] The intrinsically cross-linked network benzocyclobutene resin prepared from the intrinsically cross-linked benzocyclobutene monomer containing unsaturated double bonds shown in Formula I is used as a packaging material or interlayer insulating material in the fields of ultra-large-scale integrated circuit multi-chip modules, polymer film waveguides, wafer-level chip scale packaging, micro-electromechanical systems, liquid crystal display packaging, and signal insulation component packaging, and also falls within the scope of protection of the present invention.

[0065] The present invention also provides a product.

[0066] The product contains the above monomer, or the product is prepared using the above monomer;

[0067] Preferably, the product is a sheet or film polymerized from the monomer, or the product contains a sheet or film polymerized from the monomer.

[0068] The article is prepared by the following method: forming a sheet or film of the monomer represented by formula I by a method selected from the group consisting of heated molding, solution spin coating, or solution drop coating;

[0069] Preferably, the solution spin coating or solution drop coating comprises the steps of: dissolving the monomer represented by formula I in an organic solvent to form a solution.

[0070] The present invention also provides a photoresist, which is prepared from components including a prepolymer of unsaturated double-bond intrinsically cross-linked benzocyclobutene as shown in formula I, a photosensitizer and an organic solvent.

[0071] The technologies not mentioned in this invention are all referred to the prior art.

[0072] The beneficial effects achieved by the present invention are:

[0073] (1) The present invention uses 1,4-dibromo-2,5-xylene and 1,4-dichloro-2,5-dibromobenzene as raw materials, and sequentially undergoes four reactions to obtain an intrinsically cross-linked benzocyclobutene monomer containing an unsaturated double bond. The preparation method is simple and the reaction mode is novel. At the same time, the polymer prepared using the intrinsically cross-linked benzocyclobutene monomer containing an unsaturated double bond as the raw material has significantly improved dielectric properties, thermal stability and hydrophobicity.

[0074] (2) The dielectric loss of the polymer obtained by curing the intrinsic cross-linked benzocyclobutene monomer containing unsaturated double bonds prepared by the present invention is low, both of which are 1.87×10 -3 Dielectric constant D k The polymer has excellent thermal stability ( T 5% >483 ℃). It has high elastic modulus (5.3 GPa) and hardness (0.66 GPa). Its thermal expansion coefficient is (48 ppm / ℃)

[0075] (3) The intrinsic cross-linked benzocyclobutene monomer containing unsaturated double bonds of the present invention fully utilizes the cyclization reaction and rigid spatial structure of norbornadiene, providing a new idea for the development of low dielectric packaging materials.

[0076] Based on the reactive properties of benzocyclobutene (BCB), this invention introduces a norbornadiene (NB) structure into the resin monomer. Norbornadiene is a cyclic olefin whose chemical structure consists of a methylene bridge and a cyclohexene. The bridged ring structure exhibits high tension, while the presence of a double bond imparts high chemical reactivity. We employed a polymerization method based on the highly efficient catalytic aromatic-norbornene cyclization (CANAL) developed by Professor Xia Yan of Stanford University to successfully synthesize the norbornadiene benzocyclobutene unit by catalyzing the cyclization of an aromatic bromide and norbornadiene. Based on this, we successfully prepared two new multi-reactive site cruciform benzocyclobutene monomers, effectively increasing the crosslink density and reducing the dielectric constant. The cured resin forms a regular crosslinked network structure under the directional action of the Diels-Alder reaction, enabling the resin material to better meet the higher requirements for dielectric layer materials in future high-frequency communication technologies. BRIEF DESCRIPTION OF THE DRAWINGS

[0077] Figure 1 This is the H NMR spectrum of 1,4-2,5-di(bromoethyl)benzene obtained in Example 1.

[0078] Figure 2 This is the C NMR spectrum of 1,4-2,5-di(bromoethyl)benzene obtained in Example 1.

[0079] Figure 3 This is the H NMR spectrum of 1,4-diallyl-2,5-dibromobenzene obtained in Example 1.

[0080] Figure 4 This is the H NMR spectrum of 1,4-diallyl-2,5-dibenzocyclobutene obtained in Example 1.

[0081] Figure 5 This is the C NMR spectrum of 1,4-diallyl-2,5-dibenzocyclobutene obtained in Example 1.

[0082] Figure 6 This is the H NMR spectrum of NBD-CL obtained in Example 1.

[0083] Figure 7 This is the C NMR spectrum of NBD-CL obtained in Example 1.

[0084] Figure 8 This is the H NMR spectrum of NBD-BCB obtained in Example 1.

[0085] Figure 9 This is the mass spectrum of NBD-BCB obtained in Example 1.

[0086] Figure 10 are the TGA curves of the two polymers.

[0087] Figure 11 is the CTE of the two polymers in the temperature range of 50-250°C.

[0088] Figure 12 are the static contact angles of the two polymers, (a) is the static contact angle of A-BCB polymer, and (b) is the static contact angle of NBD-BCB polymer.

[0089] Figure 13 are the hardness and elastic modulus of the two polymer materials. DETAILED DESCRIPTION

[0090] The present invention will be further described in detail below in conjunction with specific embodiments. The examples provided are only for illustrating the present invention and are not intended to limit the scope of the present invention. The examples provided below can serve as a guide for further improvements by those skilled in the art and are not intended to limit the present invention in any way.

[0091] Unless otherwise specified, the experimental methods in the following examples are conventional methods and were performed according to the techniques or conditions described in the literature in the field or according to the product instructions. The materials and reagents used in the following examples, unless otherwise specified, were all commercially available.

[0092] Example 1

[0093] An intrinsically cross-linked benzocyclobutene monomer containing an unsaturated double bond, the molecular structure of which is

[0094]

[0095] The preparation method comprises the following steps:

[0096] 1) Add 5 g of 1,4-dibromo-2,5-dimethylbenzene, 7.1 g of NBS, and 0.164 g of AIBN to a dry, three-necked flask equipped with a magnetic stirrer. After replacing the atmosphere with nitrogen three times, add 75 ml of ultra-dry acetonitrile via syringe. Wrap the flask in aluminum foil to protect it from light. Then, place the system in an oil bath and react at 100°C for 24 hours. After the reaction, cool the system to room temperature. Filter the reaction product through diatomaceous earth to remove excess inorganic salts and other insoluble matter. Rinse the product three times with dichloromethane, and the filtrate is collected and rotary evaporated under reduced pressure. The crude product is washed with hot methanol to obtain a white solid: 1,4-2,5-di(bromoethyl)benzene, represented by Formula II.

[0097] like Figure 1 As shown, the structural characterization of 1,4-2,5-di(bromoethyl)benzene: 1 H NMR (300 MHz, Chloroform-d)δ (ppm): 7.65 (d, J= 1.1 Hz, 2H), 4.50 (d, J = 1.0 Hz, 4H).

[0098] like Figure 2 Shown is the carbon spectrum of 1,4-2,5-di(bromoethyl)benzene.

[0099] from Figure 1 and Figure 2 The target product 1,4-2,5-di(bromoethyl)benzene was confirmed to be obtained.

[0100] 2) Add 10.54 g of the compound 1,4-2,5-di(bromoethyl)benzene and 4.75 g of cuprous iodide to a dried, three-necked flask equipped with a magnetic stirrer. After replacing the nitrogen atmosphere three times, add 260 ml of ultra-dry dichloromethane via syringe. Place the system in an acetone bath, cool the acetone to -78°C with liquid nitrogen, and add 110 mmol of vinylmagnesium bromide via syringe pump over 1 hour. The mixture is stirred at -78°C for 3 hours. Afterwards, the acetone bath is removed and the temperature is slowly returned to room temperature. Saturated ammonium chloride solution is then slowly added to the system with stirring to quench the reaction. After completion of the quenching reaction, the organic and aqueous phases are filtered through celite. The filter cake is rinsed three times with dichloromethane, and the product is extracted with ethyl acetate using a separatory funnel. The combined organic matter was extracted three times with saturated brine, dried over anhydrous magnesium sulfate overnight, and excess solvent was removed using a rotary evaporator. The product was concentrated and separated by column chromatography using a dry loading method. The product was a white solid: 1,4-diallyl-2,5-dibromobenzene, a compound represented by Formula III.

[0101] like Figure 3 As shown, the H NMR spectrum of compound 1,4-diallyl-2,5-dibromobenzene is: 1 H NMR (300 MHz, Chloroform-d) δ = 7.40 (s, 2H), 5.93 (ddt, J =16.7, 10.1, 6.5, 2H), 5.23-5.02 (m, 4H), 3.44 (dt, J =6.6, 1.5, 4H).

[0102] from Figure 3 It can be confirmed that the target product compound 1,4-diallyl-2,5-dibromobenzene is obtained.

[0103] 3) A mixture of 1,4-diallyl-2,5-dibromobenzene (6.32 g), 4BpinBCB (9.205 g), and Na₂CO₃ (10.918 g) was added to a 250 ml three-necked flask equipped with a magnetic stirrer. Then, 25 ml of water, 50 ml of ethanol, and 100 ml of dioxane were added. The system was placed in an ice-water bath and bubbling was performed for 30 minutes to remove oxygen from the system. Pd(PPh₃)₄ (1.155 g) was then added. The mixture was then stirred at 110°C for 24 hours. After the reaction, the residual solid was filtered off, and the product was extracted with saturated brine and dichloromethane. The organic phase was dehydrated over anhydrous magnesium sulfate overnight. The crude product was purified by column chromatography on silica gel using a 1:100 ratio of ethyl acetate to petroleum ether as the eluent, obtaining the compound 1,4-diallyl-2,5-dibenzocyclobutene (Formula I-a) as a white solid.

[0104] Figure 4 This is the H-NMR spectrum of the compound 1,4-diallyl-2,5-dibenzocyclobutene: 1 H NMR (300 MHz, Chloroform-d) δ = 7.21-7.04 (m, 8H), 5.90 (dd, J =16.8, 10.3, 2H), 4.97 (d, J =16.9, 4H), 3.35 (d, J =6.5, 4H), 3.24 (s, 8H).

[0105] Figure 5 This is the carbon spectrum of the compound 1,4-diallyl-2,5-dibenzocyclobutene;

[0106] from Figure 4 and Figure 5 It can be confirmed that the target product compound 1,4-diallyl-2,5-dibenzocyclobutene is obtained.

[0107] Example 2

[0108] An intrinsically cross-linked benzocyclobutene monomer containing an unsaturated double bond, the molecular structure of which is:

[0109]

[0110] The preparation method comprises the following steps:

[0111] 1) To a flame-dried 150 mL glass pressure bottle, add 4.52 g of 1,4-dichloro-2,5-dibromobenzene, 6.91 g of norbornadiene, 20.069 g of Pd(OAc), and 30.1606 g of PPh. The pressure bottle was transferred to a nitrogen glove box and 9.79 g of Cs2CO3 and 45 mL of 1,4-dioxane were added. The pressure bottle was then sealed with a Teflon valve and removed from the glove box. The mixture was stirred in a 150°C oil bath for 24 hours. Afterward, the mixture was cooled to room temperature, passed through a thin layer of celite to remove inorganic salts, and washed with chloroform (3 × 5 mL). The filtrate was concentrated on a rotary evaporator. The product was subjected to column chromatography using pure petroleum ether as the eluent to obtain the compound of Formula IV as a white solid.

[0112] like Figure 6 The H NMR spectrum of the compound represented by formula IV is: 1 H NMR (300 MHz, Chloroform-d) δ = 6.23(s, 4H), 3.07 (s, 4H), 2.88 (d, J =2.2, 4H), 1.43-1.19 (m, 2H), 0.96-0.74 (m,2H).

[0113] like Figure 7 This is the C NMR spectrum of the compound represented by formula IV;

[0114] from Figure 6 and Figure 7 It was confirmed that the target compound was obtained.

[0115] 2) To a 150 mL glass pressure bottle was added the compound of Formula IV (3.27 g), 4BpinBCB (4.60 g), Pd2(dba)3 (0.277 g), P(tBu)3HBF4 (0.41 g), and KF (3.84 g). The pressure bottle was then transferred to a nitrogen glove box, and 15 mL of THF and 5 mL of deionized water were added. The pressure bottle was sealed with a Teflon valve, removed from the glove box, and heated in a 90°C oil bath for 10 h. The mixture was then cooled to room temperature and passed through Celite to remove inorganic salts. The residue was washed with dichloromethane (3 × 5 mL). The filtrate was collected and concentrated on a rotary evaporator and purified by chromatography on a neutral alumina column using pure petroleum ether as the eluent to obtain the compound of Formula I-b.

[0116] like Figure 8 The NMR hydrogen spectrum of compound NBD-BCB is shown as follows: 1H NMR (300 MHz, Chloroform-d) δ= 7.73 (d, J =7.5, 2H), 7.56 (s, 2H), 7.15 (d, J =7.7, 2H), 6.31 (s, 4H), 3.31(s, 4H), 3.30-3.21 (m, 9H), 2.99-2.91 (m, 4H), 1.31 (d, J =9.0, 2H), 1.10 (d, J =9.1, 3H).

[0117] like Figure 9 Shown is the mass spectrum of the compound represented by formula I-b;

[0118] from Figure 8 and Figure 9 It was confirmed that the target compound was obtained.

[0119] Example 3

[0120] 0.8 g of the intrinsically cross-linked benzocyclobutene monomer containing unsaturated double bonds obtained in Example 1 and 3.2 g of mesitylene were added to a Schlenk tube, maintaining a solids content of 20%. Three freeze-pump-thaw cycles were performed to remove oxygen from the mixture. The Schlenk tube was sealed and heated and stirred at 160°C for 24 hours to obtain a prepolymer. Excess mesitylene was removed by rotary evaporation to maintain a prepolymer concentration of 400 mg / ml. 1 ml of prepolymer with a concentration of 400 mg / ml was added to a stainless steel tank with a diameter of 3.5 cm, and 0.8 ml was added to a glass bottle with a diameter of 1 cm. The stainless steel tank and glass bottle were placed in a high-temperature nitrogen curing oven and gradient heated under a nitrogen atmosphere (150°C for 1 hour, 200°C for 1 hour, 235°C for 1 hour, 260°C for 3 hours, and 300°C for 1 hour) to completely cure the polymer and obtain the final polymer sheet.

[0121] The thermogravimetric analysis curve of the polymer is shown in Figure 10 As shown by the solid line, the temperature at which the thermal weight loss of the cured polymer reaches 5% is 353 °C, indicating that the cured polymer has good heat resistance.

[0122] The thermal expansion coefficient of the polymer is 62.21 ppm / ℃, such as Figure 11 The dotted line shows that the polymer has good dimensional stability ( Figure 11 ).

[0123] The contact angle diagram of the polymer is shown in Figure 12 As shown in (a), the contact angle reaches 89°, indicating that the polymer obtained after curing has good hydrophobicity.

[0124] The hardness of the polymer is 0.48 GPa and the elastic modulus is 4.8 GPa. Figure 13 As shown by the solid line, it shows that the material has certain mechanical properties.

[0125] Example 4

[0126] 0.8 g of the intrinsically cross-linked benzocyclobutene monomer containing unsaturated double bonds obtained in Example 2 and 3.2 g of mesitylene were added to a Schlenk tube, maintaining a solids content of 20%. Three freeze-pump-thaw cycles were performed to remove oxygen from the mixture. The Schlenk tube was sealed and heated and stirred at 160°C for 24 hours to obtain a prepolymer. Excess mesitylene was removed by rotary evaporation to maintain a prepolymer concentration of 400 mg / ml. 1 ml of prepolymer with a concentration of 400 mg / ml was added to a stainless steel tank with a diameter of 3.5 cm, and 0.8 ml was added to a glass bottle with a diameter of 1 cm. The stainless steel tank and glass bottle were placed in a high-temperature nitrogen curing oven and gradient heated under a nitrogen atmosphere (150°C for 1 hour, 200°C for 1 hour, 235°C for 1 hour, 260°C for 3 hours, and 300°C for 1 hour) to completely cure the polymer and obtain the final polymer sheet.

[0127] The thermogravimetric analysis curve of the polymer is as follows Figure 10 As shown by the dotted line, the temperature at which the thermal weight loss of the cured polymer reaches 5% is 483°C, indicating that the cured polymer has good heat resistance.

[0128] The thermal expansion coefficient of the polymer is 48 ppm / °C. Figure 11 The solid line shows that the polymer has good dimensional stability ( Figure 11 ).

[0129] The contact angle diagram of the polymer is shown in Figure 12 As shown in (b), the contact angle reaches 103°, indicating that the polymer obtained after curing has good hydrophobicity.

[0130] The hardness of the polymer is 0.66 GPa and the elastic modulus is 5.3 GPa. Figure 13 The dotted line shows that the polymer has certain mechanical properties.

[0131] Table 1 shows the dielectric constants and dielectric losses of the two polymer materials at 10 GHz. The dielectric constants and dielectric losses of the two polymer films were characterized by placing them in the resonant cavity of a 10 GHz split-pillar dielectric resonator (SPDR) equipped with a microwave Q-meter.

[0132] Table 1 Dielectric constants and dielectric losses of two polymer materials at 10 GHz

[0133]

[0134] The present invention has been described in detail above. For those skilled in the art, without departing from the purpose and scope of the present invention, and without the need to carry out unnecessary experimental conditions, the present invention can be implemented in a wide range under equivalent parameters, concentrations and conditions. Although the present invention provides specific embodiments, it should be understood that further improvements can be made to the present invention. In short, according to the principles of the present invention, this application is intended to include any changes, uses or improvements to the present invention, including changes that depart from the disclosed scope in this application and are made using conventional techniques known in the art.

Claims

1. An intrinsically cross-linked benzocyclobutene monomer containing an unsaturated double bond, the structural formula of which is shown in Formula I: In formula I, R is selected from or .

2. A method for preparing the intrinsically cross-linked benzocyclobutene monomer according to claim 1, comprising the steps of: using 1,4-dibromo-2,5-dimethylbenzene as a raw material, sequentially subjecting the monomer to bromination, Grignard reaction, and Suzuki reaction to obtain an intrinsically cross-linked benzocyclobutene monomer containing an unsaturated double bond, the structural formula of which is shown in Formula I-a; or Using 1,4-dichloro-2,5-dibromobenzene as the raw material, a catalytic aromatic norbornene cyclization reaction (CNANL reaction) and a Suzuki reaction are sequentially performed to obtain an intrinsically cross-linked benzocyclobutene monomer containing an unsaturated double bond, the structural formula of which is shown in Formula I-b: 。 3. An intrinsically cross-linked reticulated benzocyclobutene resin having a regular network structure, prepared from an intrinsically cross-linked benzocyclobutene monomer containing unsaturated double bonds as shown in formula I in claim 1.

4. The intrinsic cross-linked network benzocyclobutene resin having a regular network structure according to claim 3, characterized in that: Its structural formula is shown in Formula V-a or Formula V-b: 。 5. The intrinsic cross-linked network benzocyclobutene resin represented by formula V-a or formula V-b in claim 4 is obtained by prepolymerizing the benzocyclobutene resin monomer represented by formula I-a or formula I-b in claim 2 in an organic solvent under the protection of an inert gas to obtain a prepolymer, and then heating and cross-linking and curing it, or directly heating and curing and cross-linking it.

6. The intrinsic cross-linked network benzocyclobutene resin according to any one of claims 3 to 5 is used as a packaging material or interlayer insulating material in the fields of ultra-large-scale integrated circuit multi-chip modules, polymer film waveguides, wafer-level chip scale packaging, micro-electromechanical systems, liquid crystal display packaging, and signal insulation component packaging.

7. An article, comprising the monomer of claim 1, or prepared using the monomer of claim 1.

8. The product according to claim 7, characterized in that The product is a sheet or film polymerized from the monomer, or the product contains a sheet or film polymerized from the monomer.

9. The article of claim 7 or 8 is prepared by forming the monomer represented by formula I into a sheet or film by a method selected from the group consisting of heated molding, solution spin coating, or solution drop coating; The solution spin coating or solution drop coating comprises the steps of: dissolving the monomer represented by formula I in an organic solvent to form a solution.

10. A photoresist prepared from the components comprising the prepolymer of the unsaturated double bond-containing intrinsically cross-linked benzocyclobutene represented by formula I according to claim 1, a photosensitizer and an organic solvent.

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