High-thermal-conductivity stainless steel for chip support and preparation method of high-thermal-conductivity stainless steel

Abstract

The invention discloses high-thermal-conductivity stainless steel for a chip support and a preparation method of the high-thermal-conductivity stainless steel, and relates to the technical field of stainless steel plating. The method comprises the following steps: plating nickel on the surface of the stainless steel substrate, then plating copper, and finally coating the high-thermal-conductivity coating to obtain the high-thermal-conductivity stainless steel for the chip bracket. The lattice matching performance of nickel and stainless steel is high, the binding force of a formed nickel-plated layer and a stainless steel substrate is high, the heat conductivity coefficient of copper is far higher than that of stainless steel, and the heat conductivity can be remarkably improved through a copper-plated layer; the high-thermal-conductivity coating comprises multi-epoxy-group epoxy resin, epoxy modified carbon nanotubes, flake silver powder, sodium stearate and a curing agent, a high-thermal-conductivity layer formed after curing of the multi-epoxy-group epoxy resin is high in crosslinking density, good in wear resistance and corrosion resistance, multiple in reaction sites and capable of being rapidly cured, and the efficiency is improved; and the epoxy modified carbon nanotubes and the flake silver powder have a synergistic effect to form comb-like dispersion, so that heat dispersion is facilitated, and the heat dissipation performance is comprehensively improved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of stainless steel plating, and particularly relates to high-thermal-conductivity stainless steel for a chip support and a preparation method thereof. BACKGROUND

[0002] The chip support is a key bearing and connecting component of a chip and is widely applied to high-end fields such as smart phones, automobile electronics and smart wear; a copper alloy lead frame has long occupied a dominant position in the field of chip packaging, at that time, the functions of electronic equipment are relatively single, and the requirements for the size and performance of the chip are not high, and the good electrical conductivity and mechanical strength of the copper alloy can basically meet the needs of chip packaging.

[0003] With the progress of science and technology, the chip develops in the direction of high performance and high integration, for example, in the field of automobile electronics, the chip needs to work stably in high temperature and strong electromagnetic interference environment, and the traditional copper alloy lead frame cannot meet the needs.

[0004] Therefore, the application provides high-thermal-conductivity stainless steel for a chip support and a preparation method thereof, so that the prepared chip support has excellent thermal conductivity and corrosion resistance. SUMMARY

[0005] The application aims to provide high-thermal-conductivity stainless steel for a chip support and a preparation method thereof to solve the problems in the prior art.

[0006] To achieve the above-mentioned purpose, the application provides the following technical scheme: a preparation method of high-thermal-conductivity stainless steel for a chip support, comprising the following steps: Step 1, taking stainless steel for cleaning, then placing it in a nickel plating solution for electroplating nickel to form a nickel plating layer, then taking it out and placing it in a copper plating solution for electroplating copper to form a copper plating layer, and obtaining composite plated stainless steel; Step 2, taking the composite plated stainless steel, coating high-thermal-conductivity paint on the surface of the composite plated stainless steel to form a high-thermal-conductivity layer, and obtaining high-thermal-conductivity stainless steel.

[0007] Further, in step 1, the nickel plating solution comprises the following mass components: 150-250 g / L nickel sulfate, 20-30 g / L nickel oxide and 20-25 g / L boric acid. The solvent of the nickel plating solution is deionized water.

[0008] Further, in step 1, the process conditions for electroplating nickel are as follows: temperature 50-60 DEG C, time 15-25 min and current density 1.0-2.0 A / dm 2 .

[0009] Further, in step 1, the copper plating solution comprises the following mass components: 10-20 g / L copper sulfate, 2-4 g / L sodium hypophosphite, 30-40 g / L citric acid, 0.005-0.01 g / L sodium dodecyl benzene sulfonate; The solvent of the copper plating solution is deionized water.

[0010] Further, in step 1, the process conditions for electroplating copper are: temperature 50-60℃, time 20-30 min, current density 1.5-2.5 A / dm 2 .

[0011] Further, in step 1, the thickness of the nickel plating layer is 1-3 μm; The thickness of the copper plating layer is 3-5 μm; In step 2, the thickness of the high-thermal-conductivity layer is 4-6 μm.

[0012] Further, in step 1, the high-thermal-conductivity coating is prepared by the following process: Mixing multi-oxygen-containing epoxy resin, epoxy-modified carbon nanotubes, flaky silver powder, sodium stearate, and curing agent in a mass ratio of 10:(0.5-1.0):(0.3-0.8):(0.1-0.3):(0.3-0.5), and stirring uniformly to obtain the high-thermal-conductivity coating.

[0013] Further, the multi-oxygen-containing epoxy resin is prepared by the following process: S1: mixing 10-undecene-1-al, 4-(trifluoromethyl)styrene, and ammonium persulfate solution, and reacting for 0.3-0.5 h, and then warming up, and then cooling down to 35-40℃, and then adding sodium bicarbonate solution to adjust pH to 8-9 to obtain a hydroxyl-containing copolymer; S2: mixing docosahexaenoic acid, m-chloroperbenzoic acid, and sodium bicarbonate solution, and reacting in an ice bath to obtain a carboxyl-containing multi-oxygen-containing compound; S3: mixing the hydroxyl-containing copolymer, the carboxyl-containing multi-oxygen-containing compound, and concentrated sulfuric acid, and reacting in an oil bath, and then cooling down to 35-40℃, and then distilling under reduced pressure to obtain the multi-oxygen-containing epoxy resin.

[0014] Further, in S1, the molar ratio of 10-undecene-1-al to 4-(trifluoromethyl)styrene is (0.9-1.1):1; The mass ratio of 10-undecene-1-al to ammonium persulfate solution is 6:(0.8-1.2); In S1, the mass fraction of the ammonium persulfate solution is 8-10%.

[0015] Further, in S1, the process conditions for warming up are: temperature 75-85℃, and time 3-5 h.

[0016] Further, in S2, the mass ratio of docosahexaenoic acid, meta-chloroperoxybenzoic acid, and sodium bicarbonate solution is 1.5: (1.5-2.5): (1.0-1.2).

[0017] Further, in S2, the process condition of ice bath reaction is: temperature 5-15℃, time 6-8h.

[0018] Further, the mass fraction of the sodium bicarbonate solution is 50%.

[0019] Further, in S3, the mass ratio of the hydroxyl-containing copolymer, the carboxyl-containing polyepoxide compound, and concentrated sulfuric acid is 10: (1.5-1.9): (1-2).

[0020] Further, in S3, the process condition of oil bath heating reaction is: temperature 100-110℃, time 8-10h.

[0021] Further, in S3, the concentration of concentrated sulfuric acid is 98%.

[0022] Further, the epoxy-modified carbon nanotube is prepared by the following process: The epoxy-modified carbon nanotube is obtained by mixing the polyepoxy epoxy resin, N-N dimethylacetamide, triphenylphosphine, and carboxylated carbon nanotube, stirring uniformly, heating reaction, and drying.

[0023] Further, the ratio of the polyepoxy epoxy resin, N-N dimethylacetamide, triphenylphosphine, and carboxylated carbon nanotube is 10g: (40-50)mL: (0.05-0.1)g: (3-5)g.

[0024] Further, the process condition of heating reaction is: temperature 70-80℃, time 20-24h; The process condition of drying is: temperature 70-80℃, time 10-12h.

[0025] Further, the curing agent is prepared by the following process: Step A: mixing 1,4-benzenedithiol, tetrahydrofuran, and dibutyltin dilaurate, heating to 55-65℃ in an oil bath, adding 2,6-diisocyanate toluene, constant temperature refluxing reaction, and rotary evaporation to obtain a thiol-containing compound; Step B: mixing the thiol-containing compound and tetrahydrofuran, heating to 65-75℃, adding diamino pyridine, continuing to react for 3-4h, and rotary evaporation to obtain the curing agent.

[0026] Further, in Step A, the molar ratio of 1,4-benzenedithiol and 2,6-diisocyanate toluene is 1: (2.0-2.2). 1,4-benzenedithiol, tetrahydrofuran, dibutyltin dilaurate, the mass ratio is 10: (50~60): (0.01~0.05).

[0027] Further, in step A, the process conditions of constant temperature reflux reaction are as follows: temperature 55~65℃, time 20~24h.

[0028] Further, in step B, the mass ratio of thiol-containing compound, tetrahydrofuran, and diamino pyridine is 1: (3~5): (0.4~0.6).

[0029] Compared with the prior art, the present application has the following advantages: 1、The present application first carries out nickel plating treatment on the stainless steel base body, and then carries out copper plating, the lattice matching of nickel and stainless steel is high, the nickel plating layer formed has high bonding force with the stainless steel base body, the nickel plating layer has a filling effect on the stainless steel base body, can improve the flatness of the stainless steel base body surface, the nickel oxide in the nickel plating solution can maintain the stability of the nickel ion concentration in the nickel plating solution, ensure the uniformity of the plating layer thickness, improve the crystallization refinement of the plating layer, the nickel layer also has certain corrosion resistance, can block the corrosion of the stainless steel base body after the oxidation of the copper plating layer; the thermal conductivity of copper is much higher than that of stainless steel, the copper plating layer can significantly improve the thermal conductivity, in addition, the lattice matching degree of copper and nickel is high, and the bonding force is good.

[0030] 2、In the present application, 10-undecen-1-ol and 4-(trifluoromethyl)styrene are first pre-reacted at room temperature under the action of ammonium persulfate to form oligomers, and then free radical copolymerization is carried out at elevated temperature, which can optimize the molecular weight distribution and retain the hydroxyl group, so as to obtain a hydroxyl-containing compound containing a benzene ring and fluorine; then, epoxidation reaction occurs between docosahexaenoic acid and m-chloroperbenzoic acid to convert double bonds into epoxy groups while retaining carboxyl groups, so as to obtain a carboxyl-containing multi-epoxy compound; finally, esterification of the hydroxyl-containing compound and the carboxyl-containing multi-epoxy compound generates a multi-epoxy epoxy resin containing a benzene ring and fluorine; the benzene ring and fluorine have high chemical inertness and are not prone to chemical corrosion, thereby improving the corrosion resistance of the coating; compared with ordinary epoxy resins, the multi-epoxy epoxy resin has higher crosslinking density after curing, better wear resistance, and more reaction sites, and can be quickly cured to improve efficiency. In the present application, one thiol group of 1,4-benzenedithiol reacts with the isocyanate group of 2,6-diisocyanatotoluene to obtain a thiol-containing compound, and then the thiol-containing compound reacts with diamino pyridine to obtain a curing agent, which has a macromolecular structure and is better compatible with the coating system than small molecule curing agents, is not prone to precipitation, and has a long molecular chain, which can improve the flexibility and impact resistance of the coating after crosslinking with the epoxy resin.

[0031] 3、Carbon nanotubes in epoxy resin is poor dispersion, therefore, the choice of carboxylated carbon nanotubes, first with multi epoxy epoxy resin, so that its surface has epoxy group, then added to the coating system, can increase its dispersion; In addition, the coating also added flaky silver powder, flaky structure dispersed in the resin matrix can form near comb type dispersion with epoxy modified carbon nanotubes, is conducive to heat dispersion, comprehensive improve the heat dissipation. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0033] In the following detailed description; Stainless steel is 304 stainless steel, from Jiangsu Yongjin Metal Technology Co., Ltd.; Flaky silver powder, average particle size 2 μm; Sodium bicarbonate solution, mass fraction of 50%; Concentrated sulfuric acid, concentration of 98%; Carbon nanotubes, average diameter 20 nm, average length 20 μm; Epoxy resin, grade E44.

[0034] Embodiment 1: a preparation method of a high-thermal-conductivity stainless steel for a chip holder, comprising the following steps: (1) Preparation of high-thermal-conductivity coating: S1: 10-undecen-1-ol, 4-(trifluoromethyl)styrene, ammonium persulfate solution were mixed, and reacted for 0.5 h, and then the reaction was warmed up, and then the reaction was cooled to 40 DEG C, and then sodium bicarbonate solution was added to adjust the pH to 9, to obtain a hydroxyl-containing copolymer; S2: docosahexaenoic acid, m-chloroperbenzoic acid, sodium bicarbonate solution were mixed, and reacted in an ice bath, to obtain a carboxyl-containing polyepoxide compound; S3: the hydroxyl-containing copolymer, the carboxyl-containing polyepoxide compound, concentrated sulfuric acid were mixed, and reacted in an oil bath, and then the reaction was cooled to 40 DEG C, and then distilled under reduced pressure, to obtain a polyepoxy epoxy resin; in S1, the molar ratio of 10-undecen-1-ol to 4-(trifluoromethyl)styrene was 1.1:1; the mass ratio of 10-undecen-1-ol to ammonium persulfate solution was 6:1.2; in S1, the mass fraction of ammonium persulfate solution was 10%; in S1, the process conditions for the warming-up reaction were: temperature 85 DEG C, time 5 h; in S2, the mass ratio of docosahexaenoic acid to m-chloroperbenzoic acid to sodium bicarbonate solution was 1.5:2.5:1.2; in S2, the process conditions for the ice-bath reaction were: temperature 15 DEG C, time 8 h; in S3, the mass ratio of the hydroxyl-containing copolymer to the carboxyl-containing polyepoxide compound to concentrated sulfuric acid was 10:1.9:2; in S3, the process conditions for the oil-bath heating reaction were: temperature 110 DEG C, time 10 h; The polyepoxy epoxy resin, N-N dimethylacetamide, triphenylphosphine, and carboxylated carbon nanotube were mixed in proportions of 10 g:50 mL:0.1 g:5 g, stirred uniformly, heated and reacted, and dried, to obtain epoxy-modified carbon nanotube; the process conditions for the heating and reaction were: temperature 80 DEG C, time 24 h; the process conditions for the drying were: temperature 80 DEG C, time 12 h; Step A: 1,4-benzenedithiol, tetrahydrofuran, dibutyltin dilaurate were mixed, and heated in an oil bath to 65 DEG C, and then 2,6-diisocyanatetoluene was added, and then the reaction was refluxed at constant temperature, and then rotary evaporation was performed, to obtain a thiol-containing compound; Step B: the thiol-containing compound, tetrahydrofuran were mixed, and then the temperature was raised to 75 DEG C, and then diamino pyridine was added, and then the reaction was continued for 4 h, and then rotary evaporation was performed, to obtain a curing agent; in Step A, the molar ratio of 1,4-benzenedithiol to 2,6-diisocyanatetoluene was 1:2.2; the mass ratio of 1,4-benzenedithiol to tetrahydrofuran to dibutyltin dilaurate was 10:60:0.05; in Step A, the process conditions for the constant-temperature reflux reaction were: temperature 65 DEG C, time 24 h; in Step B, the mass ratio of the thiol-containing compound to tetrahydrofuran to diamino pyridine was 1:5:0.6; The polyepoxy epoxy resin, epoxy-modified carbon nanotube, flaky silver powder, sodium stearate, and curing agent were mixed in a mass ratio of 10:1.0:0.8:0.3:0.5, and then stirred uniformly, to obtain a high-thermal-conductivity coating; (2) Preparation of high-thermal-conductivity stainless steel: Step 1, take stainless steel for cleaning, and then place in a nickel plating solution for electroplating nickel to form a 3 μm nickel plating layer, and then take out and place in a copper plating solution for electroplating copper to form a 5 μm copper plating layer, to obtain a composite plated stainless steel; Step 2, take the composite plated stainless steel, coat a high-thermal-conductivity paint on the surface to form a 6 μm high-thermal-conductivity layer, to obtain a high-thermal-conductivity stainless steel; in Step 1, the nickel plating solution comprises the following mass components: 250 g / L nickel sulfate, 30 g / L nickel oxide, and 25 g / L boric acid; the solvent of the nickel plating solution is deionized water; in Step 1, the copper plating solution comprises the following mass components: 20 g / L copper sulfate, 4 g / L sodium hypophosphite, 40 g / L citric acid, and 0.01 g / L sodium dodecyl benzene sulfonate; the solvent of the copper plating solution is deionized water; in Step 1, the process conditions for electroplating nickel are: temperature 60℃, time 25 min, and current density 2.0 A / dm 2 ; in Step 1, the process conditions for electroplating copper are: temperature 60℃, time 30 min, and current density 2.5 A / dm 2 .

[0035] Example 2: a preparation method of a high-thermal-conductivity stainless steel for a chip holder, comprising the following steps: (1) preparation of a high-thermal-conductivity paint: S1: mix 10-undecene-1-ol, 4-(trifluoromethyl)styrene, and ammonium persulfate solution, react for 0.4 h, warm up for reaction, cool down to 38℃, add sodium bicarbonate solution to adjust pH to 8, to obtain a hydroxyl-containing copolymer; S2: mix docosahexaenoic acid, m-chloroperbenzoic acid, and sodium bicarbonate solution, react in ice bath, to obtain a carboxyl-containing multi-epoxy compound; S3: mix the hydroxyl-containing copolymer, the carboxyl-containing multi-epoxy compound, and concentrated sulfuric acid, heat for reaction in an oil bath, cool down to 38℃, distill under reduced pressure, to obtain a multi-epoxy epoxy resin; in S1, the molar ratio of 10-undecene-1-ol to 4-(trifluoromethyl)styrene is 1.0:1; the mass ratio of 10-undecene-1-ol to ammonium persulfate solution is 6:1.0; in S1, the mass fraction of ammonium persulfate solution is 9%; in S1, the process conditions for warm-up reaction are: temperature 80℃, and time 4 h; in S2, the mass ratio of docosahexaenoic acid to m-chloroperbenzoic acid to sodium bicarbonate solution is 1.5:2.0:1.1; in S2, the process conditions for ice-bath reaction are: temperature 10℃, and time 7 h; in S3, the mass ratio of the hydroxyl-containing copolymer to the carboxyl-containing multi-epoxy compound to concentrated sulfuric acid is 10:1.7:1.5; in S3, the process conditions for oil-bath heating reaction are: temperature 105℃, and time 9 h; Mixing multi-epoxy epoxy resin, N-N dimethylacetamide, triphenylphosphine, carboxylated carbon nanotubes in proportion 10g:45mL:0.08g:4g, stirring uniformly, heating reaction, drying, obtaining epoxy modified carbon nanotubes; the process conditions of heating reaction are: temperature 75℃, time 22h; the process conditions of drying are: temperature 75℃, time 11h; Step A: mixing 1,4-benzenedithiol, tetrahydrofuran, dibutyltin dilaurate, heating to 60℃ in oil bath, adding 2,6-diisocyanate toluene, constant temperature refluxing reaction, rotary evaporation, obtaining thiol-containing compound; Step B: mixing thiol-containing compound, tetrahydrofuran, heating to 70℃, adding diamino pyridine, continuing to react for 3.5h, rotary evaporation, obtaining curing agent; in Step A, the molar ratio of 1,4-benzenedithiol, 2,6-diisocyanate toluene is 1:2.1; the mass ratio of 1,4-benzenedithiol, tetrahydrofuran, dibutyltin dilaurate is 10:55:0.03; in Step A, the process conditions of constant temperature refluxing reaction are: temperature 60℃, time 22h; in Step B, the mass ratio of thiol-containing compound, tetrahydrofuran, diamino pyridine is 1:4:0.5; Mixing multi-epoxy epoxy resin, epoxy modified carbon nanotubes, flaky silver powder, sodium stearate, curing agent in mass ratio 10:0.8:0.5:0.2:0.4, stirring uniformly, obtaining high thermal conductivity coating; (2) Preparation of high thermal conductivity stainless steel: Step 1, taking stainless steel for cleaning, then placing in nickel plating solution, electroplating nickel to form 2μm nickel plating layer, then taking out and placing in copper plating solution, electroplating copper to form 4μm copper plating layer, obtaining composite plated stainless steel; Step 2, taking composite plated stainless steel, coating high thermal conductivity coating on its surface to form 5μm high thermal conductivity layer, obtaining high thermal conductivity stainless steel; in Step 1, the nickel plating solution comprises the following mass components: 200g / L nickel sulfate, 25g / L nickel oxide, 23g / L boric acid; the solvent of the nickel plating solution is deionized water; in Step 1, the copper plating solution comprises the following mass components: 15g / L copper sulfate, 3g / L sodium hypophosphite, 35g / L citric acid, 0.008g / L sodium dodecyl benzene sulfonate; the solvent of the copper plating solution is deionized water; in Step 1, the process conditions of electroplating nickel are: temperature 55℃, time 20min, current density 1.5A / dm 2 ; in Step 1, the process conditions of electroplating copper are: temperature 55℃, time 25min, current density 2.0A / dm 2 .

[0036] Example 3: a method for preparing high thermal conductivity stainless steel for chip support, comprising the following steps: (1) Preparation of high thermal conductivity coating: S1: 10-undecen-1-ol, 4-(trifluoromethyl)styrene, ammonium persulfate solution were mixed, and the reaction was carried out for 0.3 h, the temperature was raised, and the temperature was lowered to 35℃, sodium bicarbonate solution was added to adjust the pH to 8, and a hydroxyl-containing copolymer was obtained; S2: docosahexaenoic acid, m-chloroperbenzoic acid, sodium bicarbonate solution were mixed, and the reaction was carried out in an ice bath to obtain a carboxyl-containing polyepoxide compound; S3: the hydroxyl-containing copolymer, the carboxyl-containing polyepoxide compound, and concentrated sulfuric acid were mixed, and the reaction was carried out in an oil bath, and the temperature was lowered to 35℃, and the reaction was carried out under reduced pressure to obtain a polyepoxy epoxy resin; in S1, the molar ratio of 10-undecen-1-ol to 4-(trifluoromethyl)styrene was 0.9:1; the mass ratio of 10-undecen-1-ol to ammonium persulfate solution was 6:0.8; in S1, the mass fraction of ammonium persulfate solution was 8%; in S1, the process conditions for the temperature-raising reaction were: temperature 75℃, time 3h; in S2, the mass ratio of docosahexaenoic acid, m-chloroperbenzoic acid, and sodium bicarbonate solution was 1.5:1.5:1.0; in S2, the process conditions for the ice bath reaction were: temperature 5℃, time 6h; in S3, the mass ratio of the hydroxyl-containing copolymer, the carboxyl-containing polyepoxide compound, and concentrated sulfuric acid was 10:1.5:1; in S3, the process conditions for the oil bath heating reaction were: temperature 100℃, time 8h; The polyepoxy epoxy resin, N-N dimethylacetamide, triphenylphosphine, and carboxylated carbon nanotubes were mixed in proportions of 10g:40mL:0.05g:3g, stirred uniformly, heated and reacted, and dried to obtain epoxy-modified carbon nanotubes; the process conditions for the heating reaction were: temperature 70℃, time 20h; the process conditions for drying were: temperature 70℃, time 10h; Step A: 1,4-benzenedithiol, tetrahydrofuran, dibutyltin dilaurate were mixed, and the temperature was raised to 55℃ in an oil bath, 2,6-diisocyanatetoluene was added, and the reaction was carried out under constant temperature reflux, and rotary evaporation was carried out to obtain a thiol-containing compound; Step B: the thiol-containing compound, tetrahydrofuran were mixed, the temperature was raised to 65℃, and diamino pyridine was added, and the reaction was continued for 3h, and rotary evaporation was carried out to obtain a curing agent; in Step A, the molar ratio of 1,4-benzenedithiol to 2,6-diisocyanatetoluene was 1:2.0; the mass ratio of 1,4-benzenedithiol, tetrahydrofuran, and dibutyltin dilaurate was 10:50:0.01; in Step A, the process conditions for the constant temperature reflux reaction were: temperature 55℃, time 20h; in Step B, the mass ratio of the thiol-containing compound, tetrahydrofuran, and diamino pyridine was 1:3:0.4; The polyepoxy epoxy resin, epoxy-modified carbon nanotubes, flaky silver powder, sodium stearate, and a curing agent were mixed in a mass ratio of 10:0.5:0.3:0.1:0.3, and stirred uniformly to obtain a high-thermal-conductivity coating; (2) Preparation of high-thermal-conductivity stainless steel: Step 1, take stainless steel for cleaning, then place in nickel plating solution, electroplating nickel, forming 1 μm of nickel plating layer, then take out and place in copper plating solution, electroplating copper, forming 3 μm of copper plating layer, obtaining composite plated stainless steel; Step 2, take composite plated stainless steel, coating high-thermal-conductivity paint on the surface thereof, forming 4 μm of high-thermal-conductivity layer, obtaining high-thermal-conductivity stainless steel; in Step 1, the nickel plating solution comprises the following mass components: 150 g / L nickel sulfate, 20 g / L nickel oxide, 20 g / L boric acid; the solvent of the nickel plating solution is deionized water; in Step 1, the copper plating solution comprises the following mass components: 10 g / L copper sulfate, 2 g / L sodium hypophosphite, 30 g / L citric acid, 0.005 g / L sodium dodecyl benzene sulfonate; the solvent of the copper plating solution is deionized water; in Step 1, the process conditions for electroplating nickel are: temperature 50℃, time 15 min, current density 1.0 A / dm 2 ; in Step 1, the process conditions for electroplating copper are: temperature 50℃, time 20 min, current density 1.5 A / dm 2 .

[0037] Comparative Example 1: taking Example 1 as a comparison, replacing the multi-epoxy epoxy resin with a commercially available epoxy resin, and keeping the other conditions unchanged.

[0038] Comparative Example 2: taking Example 1 as a comparison, replacing the curing agent with ethylenediamine, and keeping the other conditions unchanged.

[0039] Comparative Example 3: taking Example 1 as a comparison, not modifying the carbon nanotubes, and keeping the other conditions unchanged.

[0040] Comparative Example 4: taking Example 1 as a comparison, replacing the multi-epoxy epoxy resin with a commercially available epoxy resin, replacing the curing agent with ethylenediamine, and not modifying the carbon nanotubes, and keeping the other conditions unchanged.

[0041] Experiment: taking the high-thermal-conductivity stainless steel obtained in the examples and comparative examples, testing the performance thereof; Thermal conductivity: using a YBF-2 type thermal conductivity tester, testing the thermal conductivity of the high-thermal-conductivity stainless steel; Corrosion resistance: referring to ASTM-B117-2011, using a 5% NaCl solution by mass fraction, testing at 35℃ for 720 h; The following table is the performance test results of the high-thermal-conductivity stainless steel;

[0042] According to the data in the above table, the following conclusions can be drawn: Compared with example 1, the thermal conductivity of stainless steel in comparative example 1 is decreased and the corrosion rate is increased, which is caused by the higher crosslinking density of the multi-epoxy epoxy resin after curing, and the benzene ring and fluorine contained in the multi-epoxy epoxy resin have high chemical inertness and are not easy to be chemically corroded; Compared with example 1, the thermal conductivity of stainless steel in comparative example 2 is decreased and the corrosion rate is increased, which is caused by the macromolecular structure of the curing agent in the example, which has better compatibility with the coating system than the small molecule curing agent and is not easy to precipitate; Compared with example 1, the thermal conductivity of stainless steel in comparative example 3 is decreased and the corrosion rate is increased, which is caused by the poor dispersibility of carbon nanotubes in the coating, which is easy to agglomerate and may cause discontinuous conduction path, resulting in the decrease of thermal conductivity; Compared with example 1, the thermal conductivity of stainless steel in comparative example 4 is the worst and the corrosion rate is the highest, which is caused by the replacement of multi-epoxy epoxy resin with commercial epoxy resin, the replacement of curing agent with ethylenediamine, and the non-modification of carbon nanotubes. In summary, the setting of the components and process conditions of the high thermal conductivity coating in the application can improve the thermal conductivity of the prepared high thermal conductivity stainless steel, while maintaining good corrosion resistance.

[0043] It is apparent for those skilled in the art that the present application is not limited to the details of the above exemplary embodiments, but can be implemented in other concrete forms without departing from the spirit or essential characteristics of the present application. Therefore, the embodiments should be considered in all aspects as exemplary and not restrictive, and the scope of the present application is defined by the appended claims rather than the above description, and all changes falling within the meaning and range of the equivalent elements of the claims are intended to be included in the present application.

Claims

1. A method for preparing high thermal conductivity stainless steel for chip holder, characterized by: The following steps are involved: Step 1: Clean the stainless steel, place it in a nickel plating solution, electroplate nickel to form a nickel layer, then take it out and place it in a copper plating solution, electroplate copper to form a copper layer, and obtain composite-coated stainless steel; Step 2: Take the composite-coated stainless steel and apply a high thermal conductivity coating on its surface to form a high thermal conductivity layer to obtain high thermal conductivity stainless steel; In step 1, the high thermal conductivity coating is prepared by the following process: The multi-epoxy epoxy resin, epoxy-modified carbon nanotubes, flaky silver powder, sodium stearate, and curing agent are mixed in a mass ratio of 10: (0.5-1.0): (0.3-0.8): (0.1-0.3): (0.3-0.5), and stirred evenly to obtain a high thermal conductive coating.

2. The method for preparing high thermal conductivity stainless steel for a chip holder according to claim 1, characterized in that: The polyepoxy epoxy resin is prepared by the following process: S1: 10-undecen-1-ol, 4-(trifluoromethyl)styrene, and ammonium persulfate solution were mixed and reacted for 0.3-0.5 h, the temperature was raised, the temperature was lowered to 35-40° C., and sodium bicarbonate solution was added to adjust the pH to 8-9 to obtain a hydroxyl-containing copolymer; S2: mixing docosahexaenoic acid, m-chloroperbenzoic acid, and sodium bicarbonate solution, and reacting them in an ice bath to obtain a carboxyl-containing polyepoxide; S3: Mix the hydroxyl-containing copolymer, the carboxyl-containing polyepoxy compound and concentrated sulfuric acid, heat in an oil bath for reaction, cool to 35-40°C, and perform vacuum distillation to obtain a polyepoxy epoxy resin.

3. The method for preparing high thermal conductivity stainless steel for a chip holder according to claim 1, characterized in that: The curing agent is prepared by the following process: Step A: 1,4-benzenedithiol, tetrahydrofuran, and dibutyltin dilaurate are mixed, heated in an oil bath to 55-65°C, 2,6-diisocyanate toluene is added, the mixture is refluxed at a constant temperature, and rotary evaporated to obtain a thiol-containing compound; Step B: Mix the thiol-containing compound and tetrahydrofuran, raise the temperature to 65-75°C, add diaminopyridine, continue the reaction for 3-4 hours, and rotary evaporate to obtain a curing agent.

4. The method for preparing high thermal conductivity stainless steel for a chip holder according to claim 1, characterized in that: The epoxy-modified carbon nanotubes are prepared by the following process: The multi-epoxy epoxy resin, NN dimethylacetamide, triphenylphosphine and carboxylated carbon nanotubes are mixed, stirred evenly, heated for reaction and dried to obtain epoxy-modified carbon nanotubes.

5. The method for preparing high thermal conductivity stainless steel for a chip holder according to claim 2, characterized in that: In S1, the molar ratio of 10-undecen-1-ol and 4-(trifluoromethyl)styrene is (0.9-1.1):1; The mass ratio of 10-undecen-1-ol and ammonium persulfate solution is 6: (0.8~1.2); In S1, the mass fraction of the ammonium persulfate solution is 8-10%.

6. The method for preparing high thermal conductivity stainless steel for a chip holder according to claim 2, characterized in that: In S2, the mass ratio of docosahexaenoic acid, m-chloroperbenzoic acid, and sodium bicarbonate solution is 1.5: (1.5~2.5): (1.0~1.2).

7. The method for preparing high thermal conductivity stainless steel for a chip holder according to claim 3, characterized in that: In step A, the molar ratio of 1,4-benzenedithiol and 2,6-diisocyanate toluene is 1:(2.0-2.2); The mass ratio of 1,4-benzenedithiol, tetrahydrofuran, and dibutyltin dilaurate is 10:(50~60):(0.01~0.05).

8. The method for preparing high thermal conductivity stainless steel for a chip holder according to claim 3, characterized in that: In step B, the mass ratio of the thiol-containing compound, tetrahydrofuran, and diaminopyridine is 1:(3-5):(0.4-0.6).

9. The method for preparing high thermal conductivity stainless steel for a chip holder according to claim 4, characterized in that: The ratio of polyepoxy epoxy resin, NN dimethylacetamide, triphenylphosphine and carboxylated carbon nanotubes is 10 g: (40-50) mL: (0.05-0.1) g: (3-5) g.

10. A high thermal conductivity stainless steel for a chip holder, characterized by: Obtained according to the preparation method according to any one of claims 1 to 9.

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