阅读说明：本技术 一种双层铜片氧化治具及氧化方法 (Double-layer copper sheet oxidation jig and oxidation method ) 是由 李炎 贺贤汉 马敬伟 蔡俊 董明锋 于 2021-08-27 设计创作，主要内容包括：本发明提供一种双层铜片氧化治具,包括上矩形框架和下矩形框架,上矩形框架和下矩形框架通过两个侧板连接,两个侧板相对设置,两个侧板上均开设有若干通气孔；一种根据所述氧化治具氧化铜片的氧化方法：将两个待氧化铜片分别放置在双层铜片氧化治具的上矩形框架和下矩形框架上,通过传送带进入氧化炉中,双层铜片氧化治具的底部和顶部同时通入氧气,达到上下两层铜片同时氧化效果；设计退火温区及通气设置,平衡上下氛围,达到两层氧化均匀的效果；为改善现有陶瓷覆铜技术中存在陶瓷层和铜层结合不致密、结合强度较低、易鼓包的情况,本发明在氧化后的铜片表面上涂覆一层改性浆料作为改性层。(The invention provides a double-layer copper sheet oxidation jig which comprises an upper rectangular frame and a lower rectangular frame, wherein the upper rectangular frame and the lower rectangular frame are connected through two side plates, the two side plates are oppositely arranged, and a plurality of vent holes are formed in the two side plates; an oxidation method for oxidizing a copper sheet according to the oxidation jig comprises the following steps: placing two copper sheets to be oxidized on an upper rectangular frame and a lower rectangular frame of a double-layer copper sheet oxidation jig respectively, feeding the copper sheets into an oxidation furnace through a conveyor belt, and introducing oxygen into the bottom and the top of the double-layer copper sheet oxidation jig simultaneously to achieve the effect of oxidizing the upper and lower copper sheets simultaneously; an annealing temperature zone and a ventilation setting are designed, the upper atmosphere and the lower atmosphere are balanced, and the effect of uniform oxidation of two layers is achieved; in order to improve the conditions of incompact combination of a ceramic layer and a copper layer, lower combination strength and easy bulging in the existing ceramic copper-clad technology, a layer of modified slurry is coated on the surface of an oxidized copper sheet to serve as a modified layer.)

1. The utility model provides a double-deck copper sheet oxidation tool which characterized in that: including last rectangular frame (1) and lower rectangular frame (2), go up rectangular frame (1) and lower rectangular frame (2) and connect through two curb plates (3), two curb plate (3) set up relatively, two all seted up a plurality of air vents (4) on curb plate (3).

2. An oxidation method for oxidizing a copper sheet by using the oxidation jig disclosed in claim 1, characterized in that: the oxidation method comprises the following steps: placing two copper sheets to be oxidized (5) on an upper rectangular frame (1) and a lower rectangular frame (2) of a double-layer copper sheet oxidation jig respectively, entering an oxidation furnace through a conveyor belt, introducing oxygen and nitrogen into the bottom and the top of the double-layer copper sheet oxidation jig simultaneously, oxidizing the upper layer and the lower layer of the copper sheets to be oxidized (5) on the double-layer copper sheet oxidation jig simultaneously, and obtaining the double-layer oxidized copper sheet.

3. An oxidation process according to claim 2, characterized in that: the double-layer copper sheet oxidation jig sequentially passes through an inlet, an warming area, a cooling area and an outlet of the oxidation furnace through a conveyor belt, the warming area comprises eleven warming areas, and the temperature of each warming area is set as follows: the first zone 540-.

4. An oxidation process according to claim 2, characterized in that: oxygen is introduced into the first zone, the second zone and the third zone in the heating zone, and the flow of the oxygen is set as follows: wherein the oxygen flow of the first zone and the second zone is 3-7mL/min, and the oxygen flow of the third zone is 100-120 mL/min; and continuously introducing nitrogen in the oxidation process, wherein the nitrogen flow at an inlet is 55-65L/min, the nitrogen flow at the tops of a first zone, a second zone, a third zone, a fourth zone, a fifth zone, a sixth zone, a seventh zone, an eighth zone, a ninth zone and a tenth zone in the temperature rising zone is 30-50L/min, the nitrogen flow at the bottoms of the first zone, the second zone, the third zone, the fourth zone, the fifth zone, the sixth zone, the seventh zone, the eighth zone, the ninth zone and the tenth zone in the temperature rising zone is 20-40L/min, the nitrogen flow at the rear zone is 80-120L/min, the nitrogen flow at a cooling zone is 55-65L/min, and the nitrogen flow at an outlet is 50-60L/min.

5. An oxidation process according to claim 2, characterized in that: the aeration pressure of the oxygen is 0.28-0.32 Mpa.

6. An oxidation process according to claim 2, characterized in that: the conveying speed of the double-layer copper sheet oxidation jig is 165-175 mm/min.

7. An oxidation process according to claim 2, characterized in that: and carrying out modification treatment on the surface of the oxidized copper sheet, and coating modified slurry on the surface of the oxidized copper sheet to form a modified layer.

8. An oxidation process according to claim 7, characterized in that: the preparation of the modified layer comprises the following steps:

(1) ultrasonically stirring isopropanol, diethylenetriamine, diisopropyl di (acetylacetonate) titanate and deionized water, uniformly mixing, carrying out hydrothermal reaction for 18-32h at the temperature of 190-;

(2) mixing and stirring glass powder, graphene oxide and vinyl triethoxysilane, ultrasonically dispersing the mixture in deionized water, and stirring the mixture for 1 to 2 hours at the temperature of between 50 and 80 ℃ to obtain a mixed solution;

(3) adding flower-shaped nano titanium dioxide and silver nitrate into the mixed solution, carrying out ultrasonic treatment, then stirring for 1-3h at 80-100 ℃, then adding ethyl cellulose, terpineol, dibutyl phthalate and polyacrylic acid, and carrying out ultrasonic stirring to obtain modified slurry;

(4) and coating the modified slurry on the surface of the oxidized copper sheet to form a modified layer.

9. An oxidation process according to claim 8, characterized in that: the volume ratio of the isopropanol, the diethylenetriamine and the diisopropyl bis (acetylacetonate) titanate in the step (1) is 1250-; in the step (2), the weight ratio of the glass powder to the graphene oxide is 1 (0.01-0.05); in the step (3), the mass ratio of the flower-shaped nano titanium dioxide to the silver nitrate is 50:1, and the weight ratio of the ethyl cellulose to the terpineol to the dibutyl phthalate to the polyacrylic acid is 2 (30-50) to 0.3 (2-5).

Technical Field

The invention relates to the technical field of copper-clad ceramic substrate preparation, in particular to a double-layer copper sheet oxidation jig and an oxidation method.

Background

The copper-clad ceramic substrate is an electronic base material prepared by sintering a copper sheet on the surface of ceramic by using a DCB technology; cuprous oxide eutectic liquid is utilized in the DBC process, so that the surface of the copper sheet needs to be oxidized before sintering, and a uniform and compact oxide layer is formed on the surface of the copper sheet; the problems of the current common copper sheet oxidation mode are as follows:

the sintered surface of the copper sheet is required to have a uniform oxide layer, and quantitative oxygen needs to be introduced at a certain temperature, but excessive oxygen can affect the surface state of the edge of the non-sintered surface of the copper sheet, cause defects such as pimples, wrinkles and the like, and affect the appearance quality and the subsequent processes of the product; the surface state of the non-sintered surface of the copper sheet can be improved by reducing the oxygen introduction amount, but because the oxygen is reduced, the oxide layer of the sintered surface of the copper sheet is uneven, the thickness is thin, and sintering bubbles are increased;

at present, the oxidation of copper sheets mostly adopts a single-side mode of bottom oxidation or top oxidation, only one side can be oxidized, and the requirement of yield increase cannot be met under the condition that the equipment capacity is limited, so that the efficiency is influenced.

In the DBC process, a contact layer copper and cuprous oxide can form a liquid phase, an aluminum oxide film with a non-compact surface is formed by oxidizing a ceramic substrate, the liquid phase permeates from a loose oxide film and is in contact with aluminum nitride, nitrogen is generated through reaction, gas cannot be discharged, small bubbles and bulges can be generated between a ceramic layer and a copper sheet, and the bonding strength of the copper sheet and the ceramic layer is reduced.

Disclosure of Invention

The invention aims to provide a double-layer copper sheet oxidation jig and an oxidation method, which aim to solve the problems in the prior art.

In order to solve the technical problems, the invention provides the following technical scheme:

the utility model provides a double-deck copper sheet oxidation tool, includes rectangular frame and lower rectangular frame, go up rectangular frame and lower rectangular frame and connect through two curb plates, two the curb plate sets up relatively, two all seted up a plurality of air vents on the curb plate.

A double-layer copper sheet oxidation method comprises the following steps: placing two copper sheets to be oxidized on an upper rectangular frame and a lower rectangular frame of the double-layer copper sheet oxidation jig respectively, entering an oxidation furnace through a conveyor belt, introducing oxygen and nitrogen into the bottom and the top of the double-layer copper sheet oxidation jig simultaneously, oxidizing an upper layer of copper sheets to be oxidized 5 and a lower layer of copper sheets to be oxidized on the double-layer copper sheet oxidation jig simultaneously, and obtaining the double-layer oxidized copper sheet.

Further, the double-layer copper sheet oxidation jig sequentially passes through an inlet, an warming area, a cooling area and an outlet of the oxidation furnace through a conveyor belt, the warming area comprises eleven warming areas, and the temperature of each warming area is set as follows: the first zone 540-.

The air inlets at the bottom and the top of the oxidation furnace are respectively provided with an oxygen inlet pipe and a nitrogen inlet pipe which are independent, the air outlets at the bottom and the top of the oxidation furnace are respectively provided with an air outlet pipe, and the air outlet flow is 4-6L/min;

oxygen is introduced into the first zone, the second zone and the third zone in the heating zone, and the flow of the oxygen is set as follows: wherein the oxygen flow of the first zone and the second zone is 3-7mL/min, and the oxygen flow of the third zone is 100-120 mL/min;

and continuously introducing nitrogen in the oxidation process, wherein the flow of the nitrogen is set as follows: wherein the nitrogen flow at the inlet is 55-65L/min, the nitrogen flow at the tops of the first zone, the second zone, the third zone, the fourth zone, the fifth zone, the sixth zone, the seventh zone, the eighth zone, the ninth zone and the tenth zone in the heating zone is 30-50L/min, the nitrogen flow at the bottoms of the first zone, the second zone, the third zone, the fourth zone, the fifth zone, the sixth zone, the seventh zone, the eighth zone, the ninth zone and the tenth zone in the heating zone is 20-40L/min, the nitrogen flow at the rear zone is 80-120L/min, the nitrogen flow at the cooling zone is 55-65L/min, and the nitrogen flow at the outlet is 50-60L/min;

the introduction amount of oxygen, nitrogen and the discharge amount of air are monitored by a pressure gauge, the pressure of the oxygen is 0.28-0.32Mpa, the pressure of the nitrogen is 0.23-0.27Mpa, and the pressure of the air is 0.28-0.32 Mpa;

the conveying speed of the double-layer copper sheet oxidation jig is 165-175 mm/min.

Further, modifying the surface of the oxidized copper sheet, and coating modified slurry on the surface of the oxidized copper sheet to form a modified layer.

Further, the preparation of the modified layer comprises the following steps:

(1) ultrasonically stirring isopropanol, diethylenetriamine, diisopropyl di (acetylacetonate) titanate and deionized water, uniformly mixing, carrying out hydrothermal reaction for 18-32h at the temperature of 190-;

the volume ratio of the isopropanol, the diethylenetriamine and the diisopropyl bis (acetylacetonate) titanate is (1250-;

(2) mixing and stirring glass powder, graphene oxide and vinyl triethoxysilane, ultrasonically dispersing the mixture in deionized water, and stirring the mixture for 1 to 2 hours at the temperature of between 50 and 80 ℃ to obtain a mixed solution;

the weight ratio of the glass powder to the graphene oxide is 1 (0.01-0.05);

(3) adding flower-shaped nano titanium dioxide and silver nitrate into the mixed solution, carrying out ultrasonic treatment, then stirring for 1-3h at 80-100 ℃, then adding ethyl cellulose, terpineol, dibutyl phthalate and polyacrylic acid, and carrying out ultrasonic stirring to obtain modified slurry;

the mass ratio of the flower-shaped nano titanium dioxide to the silver nitrate is 50:1, and the weight ratio of the ethyl cellulose to the terpineol to the dibutyl phthalate to the polyacrylic acid is 2 (30-50) to 0.3 (2-5);

(4) and coating the modified slurry on the surface of the oxidized copper sheet to form a modified layer.

In order to improve the conditions of incompact combination of a ceramic layer and a copper layer, lower combination strength and easy bulging in the existing ceramic copper-clad technology, a layer of modified slurry is coated on the surface of an oxidized copper sheet to serve as a modified layer;

preparing graphene oxide coated glass powder by using glass powder and graphene oxide, and changing the molecular weight and surface property of the glass powder to ensure that the glass powder is uniformly dispersed in the modified slurry; preparing flower-shaped nano titanium dioxide with high vacancy activity, and reducing silver nitrate by utilizing the surface vacancy activity to obtain the flower-shaped nano titanium dioxide loaded with nano silver, wherein the graphene oxide, the nano silver and the flower-shaped nano titanium dioxide can form a ternary heterojunction and play a synergistic role in changing the interface;

in the high-temperature sintering process, graphene oxide and nano-silver can form good ohmic contact at an interface and can play a synergistic role, the graphene oxide, the nano-silver and the flower-shaped nano-titanium dioxide are beneficial to being soaked at the interface, interface holes generated in the sintering process are reduced, the glass powder can form a liquid phase in the heat treatment process and can form wetting with loose alumina on the surface of the ceramic substrate, the graphene oxide, the nano-silver and the flower-shaped nano-titanium dioxide can penetrate into the pores of the loose alumina, the compactness of a surface oxide layer is improved, the cuprous oxide eutectic liquid is inhibited from permeating to generate nitrogen, and the generation of small bubbles and bulges is reduced; the graphene oxide, the nano silver and the flower-shaped nano titanium dioxide have a synergistic effect on improving the bonding strength of the copper sheet and the ceramic.

The invention has the beneficial effects that:

1. oxidizing the double layers once, and oxidizing the upper copper sheet and the lower copper sheet simultaneously;

2. on the basis of the original jig, a double-layer oxidation jig is designed, so that two layers of copper sheets can be oxidized at one time, and the efficiency is greatly improved;

3. the problems that the edge oxidation is too deep and the local size of sintered crystal grains is too large due to the fact that gas rushes on two sides of an original single layer are solved;

4. redesigning an annealing temperature zone and a ventilation setting to balance the upper and lower atmospheres and achieve the effect of uniform oxidation of the two layers;

5. in order to improve the conditions of incompact combination of a ceramic layer and a copper layer, lower combination strength and easy bulging in the existing ceramic copper-clad technology, a layer of modified slurry is coated on the surface of an oxidized copper sheet to serve as a modified layer; the modified slurry is prepared by selecting glass powder, graphene oxide, nano silver and flower-shaped nano titanium dioxide, the glass powder can form a liquid phase in the heat treatment process and can form wetting with loose alumina on the surface of a ceramic substrate, the graphene oxide, the nano silver and the flower-shaped nano titanium dioxide can penetrate into pores of the loose alumina, the compactness of a surface oxide layer is improved, the cuprous oxide eutectic liquid is inhibited from permeating to generate nitrogen, and the generation of small bubbles and bulges is reduced; the graphene oxide, the nano silver and the flower-shaped nano titanium dioxide have a synergistic effect on improving the bonding strength of the copper sheet and the ceramic.

Drawings

FIG. 1 is a structural diagram of a double-layer copper sheet oxidation jig of the present invention;

FIG. 2 is a structural diagram of a double-layer copper sheet oxidation jig according to the present invention;

FIG. 3 is a diagram of a double-layered copper sheet oxidation jig according to the present invention.

The invention relates to a double-layer copper sheet oxidation jig and an oxidation method, wherein the reference numbers in the attached drawings are used for explaining: 1-upper rectangular frame, 2-lower rectangular frame, 3-side plate, 4-vent hole and 5-copper sheet to be oxidized.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the following embodiments of the present invention, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that if directional indications such as up, down, left, right, front, and back … … are involved in the embodiment of the present invention, the directional indications are only used to explain a specific posture, such as a relative positional relationship between components, a motion situation, and the like, and if the specific posture changes, the directional indications also change accordingly. In addition, technical solutions between various embodiments may be combined with each other, but must be realized by a person skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope of the present invention.

The technical solutions of the present invention are further described in detail with reference to the following specific examples, which should be understood as merely illustrative and not limitative.

A double-layer copper sheet oxidation jig comprises an upper rectangular frame 1 and a lower rectangular frame 2, wherein the upper rectangular frame 1 and the lower rectangular frame 2 are connected through two side plates 3, the two side plates 3 are oppositely arranged, and a plurality of vent holes 4 are formed in each of the two side plates 3;

placing two copper sheets to be oxidized on an upper rectangular frame 1 and a lower rectangular frame 2 of a double-layer copper sheet oxidation jig respectively, and feeding the two copper sheets into an oxidation furnace through a conveyor belt, wherein oxygen and nitrogen are simultaneously introduced into the bottom and the top of the double-layer copper sheet oxidation jig, so that the top of an upper copper sheet to be oxidized 5 and the bottom of a lower copper sheet to be oxidized 5 can be simultaneously oxidized, and a double-layer oxidized copper sheet is obtained at a single time; a plurality of air vents are evenly arranged on two side plates of the double-layer copper sheet oxidation jig, the problem that the edge oxidation caused by the upward gas on two sides of the original single layer is too deep and the sintered crystal grains are locally too large is solved, the effect of uniform oxidation is achieved, and the oxidation efficiency is improved by using the double-layer copper sheet oxidation jig.

Example 1

Placing two copper sheets to be oxidized on an upper rectangular frame 1 and a lower rectangular frame 2 of a double-layer copper sheet oxidation jig respectively, feeding the two copper sheets to be oxidized into an oxidation furnace through a conveyor belt, introducing oxygen and nitrogen into the bottom and the top of the double-layer copper sheet oxidation jig simultaneously, and oxidizing an upper layer of copper sheet to be oxidized 5 and a lower layer of copper sheet to be oxidized on the double-layer copper sheet oxidation jig simultaneously to obtain a double-layer oxidized copper sheet;

the double-layer copper sheet oxidation jig sequentially passes through an inlet, an warming area, a cooling area and an outlet of the oxidation furnace through a conveyor belt, the warming area comprises eleven warming areas, and the temperature of each warming area is set as follows: first zone 540 deg.C, second zone 690 deg.C, third zone 790 deg.C, fourth zone 790 deg.C, fifth zone 740 deg.C, sixth zone 695 deg.C, seventh zone 666 deg.C, eighth zone 645 deg.C, ninth zone 600 deg.C, tenth zone 560 deg.C, and rear zone 519 deg.C;

the air inlets at the bottom and the top of the oxidation furnace are respectively provided with an oxygen inlet pipe and a nitrogen inlet pipe which are independent, the air outlets at the bottom and the top of the oxidation furnace are respectively provided with an air outlet pipe, and the flow rate of air is 4L/min;

oxygen is introduced into the first zone, the second zone and the third zone in the heating zone, and the flow of the oxygen is set as follows: wherein the oxygen flow of the first area and the second area is 3mL/min, and the oxygen flow of the third area is 100 mL/min;

and continuously introducing nitrogen in the oxidation process, wherein the flow of the nitrogen is set as follows: wherein the nitrogen flow at the inlet is 55L/min, the nitrogen flow at the tops of the first zone, the second zone, the third zone, the fourth zone, the fifth zone, the sixth zone, the seventh zone, the eighth zone, the ninth zone and the tenth zone in the heating zone is 30L/min, the nitrogen flow at the bottoms of the first zone, the second zone, the third zone, the fourth zone, the fifth zone, the sixth zone, the seventh zone, the eighth zone, the ninth zone and the tenth zone in the heating zone is 20L/min, the nitrogen flow at the rear zone is 80L/min, the nitrogen flow at the cooling zone is 55L/min, and the nitrogen flow at the outlet is 50L/min;

the introduction amount of oxygen, nitrogen and the discharge amount of air are monitored by a pressure gauge, the pressure of the oxygen is 0.28Mpa, the pressure of the nitrogen is 0.23Mpa, and the pressure of the air is 0.28 Mpa;

the conveying speed of the conveyor belt was 165 mm/min.

Example 2

Placing two copper sheets to be oxidized on an upper rectangular frame 1 and a lower rectangular frame 2 of a double-layer copper sheet oxidation jig respectively, feeding the two copper sheets to be oxidized into an oxidation furnace through a conveyor belt, introducing oxygen and nitrogen into the bottom and the top of the double-layer copper sheet oxidation jig simultaneously, and oxidizing an upper layer of copper sheet to be oxidized 5 and a lower layer of copper sheet to be oxidized on the double-layer copper sheet oxidation jig simultaneously to obtain a double-layer oxidized copper sheet;

the double-layer copper sheet oxidation jig sequentially passes through an inlet, an warming area, a cooling area and an outlet of the oxidation furnace through a conveyor belt, the warming area comprises eleven warming areas, and the temperature of each warming area is set as follows: first zone 550 deg.C, second zone 700 deg.C, third zone 800 deg.C, fourth zone 800 deg.C, fifth zone 750 deg.C, sixth zone 705 deg.C, seventh zone 676 deg.C, eighth zone 655 deg.C, ninth zone 610 deg.C, tenth zone 570 deg.C, and final zone 529 deg.C;

the air inlets at the bottom and the top of the oxidation furnace are respectively provided with an oxygen inlet pipe and a nitrogen inlet pipe which are independent, the air outlets at the bottom and the top of the oxidation furnace are respectively provided with an air outlet pipe, and the flow rate of air is 5L/min;

oxygen is introduced into the first zone, the second zone and the third zone in the heating zone, and the flow of the oxygen is set as follows: wherein the oxygen flow of the first area and the second area is 5mL/min, and the oxygen flow of the third area is 110 mL/min;

and continuously introducing nitrogen in the oxidation process, wherein the flow of the nitrogen is set as follows: wherein the nitrogen flow at the inlet is 60L/min, the nitrogen flow at the tops of the first zone, the second zone, the third zone, the fourth zone, the fifth zone, the sixth zone, the seventh zone, the eighth zone, the ninth zone and the tenth zone in the heating zone is 40L/min, the nitrogen flow at the bottoms of the first zone, the second zone, the third zone, the fourth zone, the fifth zone, the sixth zone, the seventh zone, the eighth zone, the ninth zone and the tenth zone in the heating zone is 20-40L/min, the nitrogen flow at the rear zone is 100L/min, the nitrogen flow at the cooling zone is 55-65L/min, and the nitrogen flow at the outlet is 55L/min;

the introduction amount of oxygen, nitrogen and the discharge amount of air are monitored by a pressure gauge, the pressure of the oxygen is 0.30Mpa, the pressure of the nitrogen is 0.25Mpa, and the pressure of the air is 0.30 Mpa;

the conveying speed of the conveyor belt was 170 mm/min.

Example 3

Placing two copper sheets to be oxidized on an upper rectangular frame 1 and a lower rectangular frame 2 of a double-layer copper sheet oxidation jig respectively, feeding the two copper sheets to be oxidized into an oxidation furnace through a conveyor belt, introducing oxygen and nitrogen into the bottom and the top of the double-layer copper sheet oxidation jig simultaneously, and oxidizing an upper layer of copper sheet to be oxidized 5 and a lower layer of copper sheet to be oxidized on the double-layer copper sheet oxidation jig simultaneously to obtain a double-layer oxidized copper sheet;

the double-layer copper sheet oxidation jig sequentially passes through an inlet, an warming area, a cooling area and an outlet of the oxidation furnace through a conveyor belt, the warming area comprises eleven warming areas, and the temperature of each warming area is set as follows: first zone 560 ℃, second zone 710 ℃, third zone 810 ℃, fourth zone 810 ℃, fifth zone 760 ℃, sixth zone 715 ℃, seventh zone 686 ℃, eighth zone 665 ℃, ninth zone 620 ℃, tenth zone 580 ℃, last zone 539 ℃;

the air inlets at the bottom and the top of the oxidation furnace are respectively provided with an oxygen inlet pipe and a nitrogen inlet pipe which are independent, the air outlets at the bottom and the top of the oxidation furnace are respectively provided with an air outlet pipe, and the flow rate of air is 6L/min;

oxygen is introduced into the first zone, the second zone and the third zone in the heating zone, and the flow of the oxygen is set as follows: wherein the oxygen flow of the first zone and the second zone is 3-7mL/min, and the oxygen flow of the third zone is 100-120 mL/min;

and continuously introducing nitrogen in the oxidation process, wherein the flow of the nitrogen is set as follows: the nitrogen flow at the inlet is 65L/min, the nitrogen flow at the tops of the first zone, the second zone, the third zone, the fourth zone, the fifth zone, the sixth zone, the seventh zone, the eighth zone, the ninth zone and the tenth zone in the heating zone is 50L/min, the nitrogen flow at the bottoms of the first zone, the second zone, the third zone, the fourth zone, the fifth zone, the sixth zone, the seventh zone, the eighth zone, the ninth zone and the tenth zone in the heating zone is 40L/min, the nitrogen flow at the rear zone is 120L/min, the nitrogen flow at the cooling zone is 65L/min, and the nitrogen flow at the outlet is 60L/min;

the introduction amount of oxygen, nitrogen and the discharge amount of air are monitored by a pressure gauge, the pressure of the oxygen is 0.32Mpa, the pressure of the nitrogen is 0.27Mpa, and the pressure of the air is 0.32 Mpa;

the conveying speed of the conveyor belt was 175 mm/min.

Example 4

The surface of the copper sheet oxidized in the example 2 is subjected to modification treatment, and the surface of the oxidized copper sheet is coated with the modified slurry to form a modified layer.

The preparation of the modified layer comprises the following steps:

(1) ultrasonically stirring isopropanol, diethylenetriamine, diisopropyl di (acetylacetonate) titanate and deionized water in a volume ratio of 1250:2:300, uniformly mixing, carrying out hydrothermal reaction at 190 ℃ for 32 hours, washing, drying, heating to 400 ℃, keeping for 2.2 hours, and cooling to obtain flower-shaped nano titanium dioxide;

(2) mixing and stirring glass powder, graphene oxide and vinyl triethoxysilane at a weight ratio of 1:0.01, ultrasonically dispersing in deionized water, and stirring at 50 ℃ for 2 hours to obtain a mixed solution;

(3) adding flower-shaped nano titanium dioxide and silver nitrate into the mixed solution, carrying out ultrasonic treatment, stirring for 3 hours at 80 ℃, adding ethyl cellulose, terpineol, dibutyl phthalate and polyacrylic acid, and carrying out ultrasonic stirring to obtain modified slurry; the weight ratio of the ethyl cellulose to the terpineol to the dibutyl phthalate to the polyacrylic acid is 2:30:2: 0.3;

(4) and coating the modified slurry on the surface of the oxidized copper sheet to form a modified layer.

Example 5

The surface of the copper sheet oxidized in the example 2 is subjected to modification treatment, and the surface of the oxidized copper sheet is coated with the modified slurry to form a modified layer.

The preparation of the modified layer comprises the following steps:

(1) ultrasonically stirring isopropanol, diethylenetriamine, diisopropyl di (acetylacetonate) titanate and deionized water in a volume ratio of 2000:6:300, uniformly mixing, carrying out hydrothermal reaction at 200 ℃ for 28 hours, washing, drying, heating to 420 ℃, keeping for 2 hours, and cooling to obtain flower-shaped nano titanium dioxide;

(2) mixing and stirring glass powder, graphene oxide and vinyl triethoxysilane at a weight ratio of 1:0.03, ultrasonically dispersing in deionized water, and stirring at 60 ℃ for 1.5 hours to obtain a mixed solution;

(3) adding flower-shaped nano titanium dioxide and silver nitrate into the mixed solution, carrying out ultrasonic treatment, then stirring for 1-3h at 90 ℃, then adding ethyl cellulose, terpineol, dibutyl phthalate and polyacrylic acid, and carrying out ultrasonic stirring to obtain modified slurry; the weight ratio of the ethyl cellulose to the terpineol to the dibutyl phthalate to the polyacrylic acid is 2:40:3: 0.3;

(4) and coating the modified slurry on the surface of the oxidized copper sheet to form a modified layer.

Example 6

The surface of the copper sheet oxidized in the example 2 is subjected to modification treatment, and the surface of the oxidized copper sheet is coated with the modified slurry to form a modified layer.

The preparation of the modified layer comprises the following steps:

(1) ultrasonically stirring isopropanol, diethylenetriamine, diisopropyl di (acetylacetonate) titanate and deionized water in a volume ratio of 2500:8:300, uniformly mixing, carrying out hydrothermal reaction at 230 ℃ for 18h, washing, drying, heating to 450 ℃, keeping for 1.8h, and cooling to obtain flower-shaped nano titanium dioxide;

(2) mixing and stirring glass powder, graphene oxide and vinyl triethoxysilane at a weight ratio of 1:0.05, ultrasonically dispersing in deionized water, and stirring at 80 ℃ for 1h to obtain a mixed solution;

(3) adding flower-shaped nano titanium dioxide and silver nitrate into the mixed solution, carrying out ultrasonic treatment, then stirring for 1h at 100 ℃, then adding ethyl cellulose, terpineol, dibutyl phthalate and polyacrylic acid, and carrying out ultrasonic stirring to obtain modified slurry; the weight ratio of the ethyl cellulose to the terpineol to the dibutyl phthalate to the polyacrylic acid is 2:40:3: 0.3;

(4) and coating the modified slurry on the surface of the oxidized copper sheet to form a modified layer.

And (3) performance testing:

the copper sheets of the embodiments 2, 4, 5 and 6 are pressed with the aluminum nitride ceramic, and the copper sheets are etched to 125mm × 6mm at the temperature of 22-24 ℃ by referring to GB/T2792-2014, the minimum peeling force and the average peeling force are measured, the minimum peeling strength and the average glass strength are calculated, and the performance tests are shown in the table 1;

TABLE 1

As can be seen from Table 1, the minimum peel strength and the average glass strength of the copper sheets in examples 4 to 6 are both greater than those of example 2, which shows that the bonding strength between the copper sheets and the small ceramic substrates in examples 4 to 6 is enhanced by coating the modified layer on the oxide layer of the copper sheets; the copper sheets prepared in examples 4 to 6 were not foamed or swelled after being laminated with the aluminum nitride ceramic, and the bonding properties between the copper sheets and the ceramic substrate were improved.

In addition, the surfaces of the two-layer copper sheets after oxidation in the embodiments 1 to 3 are flat, and uniform oxidation films are formed on the surfaces of the copper sheets, which shows that the two-layer copper sheets can be obtained by one time and the uniform oxidation films are formed on the surfaces of the copper sheets by using the oxidation method of the present invention, so as to achieve the effect of uniform oxidation.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention, and all modifications and equivalents of the present invention, which are made by the contents of the present specification and the accompanying drawings, or directly/indirectly applied to other related technical fields, are included in the scope of the present invention.