阅读说明：本技术 一种靶材组件中间层的清洗方法 (Method for cleaning intermediate layer of target assembly ) 是由 姚力军 边逸军 潘杰 王学泽 侯宇 于 2021-07-12 设计创作，主要内容包括：本发明提供了一种靶材组件中间层的清洗方法,所述清洗方法包括以下步骤：将待清洗中间层依次采用有机溶剂和水进行超声波清洗；将处理后的中间层进行鼓泡酸洗；再将处理后的中间层再次进行超声波水洗,干燥后得到清洗后的靶材组件中间层。本发明所述方法根据中间层的材质及表面污渍,依次采用超声波清洗、鼓泡酸洗以及超声波水洗的操作,将中间层表面的杂质、脏污、油污以及氧化层等充分去除,清洗后中间层的纯度较高,保证其用于扩散焊接时焊接面的致密性及均匀性,提高靶材组件的焊接强度；所述方法操作简单,清洗成本较低,产生废液量较少,适用范围广。(The invention provides a cleaning method of a target assembly interlayer, which comprises the following steps: sequentially adopting an organic solvent and water to carry out ultrasonic cleaning on the intermediate layer to be cleaned; carrying out bubbling acid washing on the treated middle layer; and then carrying out ultrasonic washing on the treated intermediate layer again, and drying to obtain the washed intermediate layer of the target assembly. According to the method, the operations of ultrasonic cleaning, bubbling acid cleaning and ultrasonic water washing are sequentially adopted according to the material and surface stains of the intermediate layer, so that impurities, dirt, oil stains, oxide layers and the like on the surface of the intermediate layer are fully removed, the purity of the cleaned intermediate layer is high, the compactness and uniformity of a welding surface when the intermediate layer is used for diffusion welding are ensured, and the welding strength of the target assembly is improved; the method is simple to operate, low in cleaning cost, less in waste liquid amount and wide in application range.)

1. A cleaning method for an intermediate layer of a target assembly is characterized by comprising the following steps:

(1) sequentially adopting an organic solvent and water to carry out ultrasonic cleaning on the intermediate layer to be cleaned;

(2) carrying out bubbling acid washing on the intermediate layer treated in the step (1);

(3) and (3) carrying out ultrasonic washing on the intermediate layer processed in the step (2) again, and drying to obtain the cleaned intermediate layer of the target assembly.

2. The cleaning method according to claim 1, wherein the material of the intermediate layer in the step (1) comprises titanium;

preferably, the shape of the intermediate layer of step (1) comprises a disc shape;

preferably, the thickness of the intermediate layer in the step (1) is 2.6-3.5 mm.

3. The cleaning method according to claim 1 or 2, wherein the organic solvent of step (1) comprises any one or a combination of at least two of isopropyl alcohol, ethanol or kerosene;

preferably, the frequency of the ultrasonic wave during the ultrasonic cleaning in the step (1) is 42-60 kHz;

preferably, the temperature of the ultrasonic cleaning in the step (1) is 15-25 ℃;

preferably, the ultrasonic cleaning in step (1) with organic solvent and water is carried out for 3-6 min independently.

4. The cleaning method according to any one of claims 1 to 3, wherein the acid used in the bubble acid cleaning in step (2) comprises nitric acid and/or hydrofluoric acid;

preferably, the temperature of the bubbling acid washing in the step (2) is 30-35 ℃;

preferably, the bubbling acid washing time in the step (2) is 1-3 min.

5. The cleaning method according to any one of claims 1 to 4, wherein a gas is introduced into the pickling solution during the bubbling pickling in the step (2);

preferably, the introduced gas comprises compressed air;

preferably, after the bubbling acid washing in the step (2) is finished, the intermediate layer is soaked in water for washing;

preferably, the time for soaking and washing is 4-6 min.

6. The cleaning method according to any one of claims 1 to 5, wherein the number of times of the ultrasonic water washing in the step (3) is at least 1, preferably 2 to 3;

preferably, the frequency of the ultrasonic wave in the ultrasonic wave water washing in the step (3) is 42-60 kHz;

preferably, the temperature of the ultrasonic water washing in the step (3) is 15-25 ℃;

preferably, the total time of the ultrasonic water washing in the step (3) is 10-20 min.

7. The cleaning method according to any one of claims 1 to 6, wherein the drying in step (3) comprises purge drying and vacuum drying in this order;

preferably, the purging and drying uses compressed gas to purge the intermediate layer;

preferably, the compressed gas comprises an inert gas and/or nitrogen;

preferably, the pressure of the compressed gas is 1-5 kPa;

preferably, the time of blowing and drying is 4-6 min.

8. The cleaning method according to claim 7, wherein the temperature of the vacuum drying is 60 to 100 ℃;

preferably, the pressure of the vacuum drying is-0.09 to-0.1 MPa;

preferably, the vacuum drying time is 40-90 min.

9. The cleaning method according to any one of claims 1 to 8, wherein the intermediate layer is detected and packaged after being cleaned;

preferably, the detecting comprises performing purity detection on the cleaned intermediate layer;

preferably, the packaging is vacuum packaging of the cleaned intermediate layer.

10. A cleaning method according to any one of claims 1-9, characterized in that the cleaning method comprises the steps of:

(1) sequentially carrying out ultrasonic cleaning on an intermediate layer to be cleaned by adopting an organic solvent and water, wherein the material of the intermediate layer comprises titanium, the thickness of the intermediate layer is 2.6-3.5 mm, the organic solvent comprises any one or a combination of at least two of isopropanol, ethanol or kerosene, the frequency of ultrasonic waves is 42-60 kHz during ultrasonic cleaning, the temperature is 15-25 ℃, and the time for ultrasonic cleaning by adopting the organic solvent and the water is independently 3-6 min;

(2) carrying out bubbling pickling on the intermediate layer treated in the step (1), wherein acid used in the bubbling pickling comprises nitric acid and/or hydrofluoric acid, the temperature of the bubbling pickling is 30-35 ℃, the time is 1-3 min, gas is introduced into a pickling solution in the bubbling pickling process, and after the bubbling pickling is finished, the intermediate layer is placed in water for soaking and washing for 4-6 min;

(3) and (3) carrying out ultrasonic washing on the intermediate layer treated in the step (2) again, wherein the frequency of the ultrasonic washing is at least 1 time, the frequency of the ultrasonic is 42-60 kHz, the temperature is 15-25 ℃, the total time is 10-20 min, then carrying out purging drying and vacuum drying in sequence, wherein compressed gas is used for purging the intermediate layer in the purging drying, the pressure of the compressed gas is 1-5 kPa, the purging drying time is 4-6 min, the vacuum drying temperature is 60-100 ℃, the pressure is-0.09-0.1 MPa, and the time is 40-90 min, so as to obtain the cleaned intermediate layer of the target assembly.

Technical Field

The invention belongs to the technical field of target preparation, and relates to a method for cleaning an intermediate layer of a target assembly.

Background

With the rapid development of the semiconductor industry, the demand of coating materials as important materials for manufacturing semiconductor electronic devices is increasing. The target material is used as an important coating material and has wide application in the fields of integrated circuits, flat panel displays, solar energy, optical devices and the like, and the main preparation method is a Physical Vapor Deposition (PVD) method, wherein the sputtering coating method is the most common method.

In the sputtering coating process, the target is generally not used independently, but is in the form of a target assembly, the target assembly is generally composed of the target and a back plate, and the target assembly is in a severe working environment and needs high welding strength of the target and the back plate, so that the target assembly is prevented from deforming, cracking and the like under a heated condition. At present, one of the most common methods for welding the target material and the back plate is diffusion welding, which is usually hot isostatic pressing welding under high temperature and high pressure conditions, but when the material difference between the target material and the back plate is large, the bonding property between the target material and the back plate is weak, at this time, an intermediate layer is required to be adopted for assistance, and the target material assembly with high welding strength is obtained by utilizing the characteristic that the bonding property of the intermediate layer to the target material and the back plate is relatively strong.

In order to ensure the smooth operation of the welding process, the intermediate layer needs to be cleaned in advance so as to avoid the defects of insufficient welding compactness and influence on welding strength caused by the pollution of impurities, dirt and the like on the welding surface, but the conventional target assembly welding only relates to the cleaning of the target and the back plate, the cleaning of the target mainly refers to the quality of sputtering coating, and the research on the use and cleaning of the intermediate layer is less. CN 108816929A discloses a cleaning method of a semi-finished tantalum thread in a tantalum target production process, which comprises the following steps: and (3) performing ultrasonic treatment on the tantalum threads for 3-10min, coating a cleaning agent on the surfaces, and then performing brushing, blow-drying and vacuum drying. The cleaning process is carried out in the manufacturing process of the target assembly, the purpose is to improve the welding bonding rate of the target and the back plate, the use and the cleaning of the intermediate layer are not involved, and the corresponding cleaning methods are different due to different use requirements of the target and the intermediate layer.

CN 109022792a discloses a method for treating a target material to be treated, which comprises: providing a target material to be treated; performing first acid washing treatment on the target material to be treated through a first acid solution to form an initial target material, wherein the first acid solution and the target material to be treated generate a first chemical reaction to remove partial material on the surface of the target material; and carrying out second acid washing treatment on the initial target through a second acid solution, wherein the second acid solution and the initial target generate a second chemical reaction, and part of the material on the surface of the initial target is removed, and the rate of the second chemical reaction is smaller than that of the first chemical reaction. The method emphasizes the acid pickling treatment of the waste target material to improve the recovery rate of the target material, and the single acid pickling treatment cannot meet the requirement of direct use for welding.

In summary, for the selection of the cleaning manner of the intermediate layer of the target assembly, an appropriate operation step needs to be selected according to the material and the surface characteristics of the intermediate layer, so as to ensure the cleaning effect and meet the requirements of subsequent welding use.

Disclosure of Invention

Aiming at the problems in the prior art, the invention aims to provide a method for cleaning an intermediate layer of a target assembly, which is characterized in that according to the material and surface stains of the intermediate layer, the operations of ultrasonic cleaning, bubbling acid cleaning and ultrasonic water washing are sequentially adopted to fully remove impurities, dirt, oil stains, an oxide layer and the like on the surface of the intermediate layer, so that the compactness and uniformity of a welding surface are ensured without being affected by impurities when the intermediate layer is diffusion-welded with a target and a back plate, and the welding strength is improved.

In order to achieve the purpose, the invention adopts the following technical scheme:

the invention provides a cleaning method of a target assembly interlayer, which comprises the following steps:

(1) sequentially adopting an organic solvent and water to carry out ultrasonic cleaning on the intermediate layer to be cleaned;

(2) carrying out bubbling acid washing on the intermediate layer treated in the step (1);

(3) and (3) carrying out ultrasonic washing on the intermediate layer processed in the step (2) again, and drying to obtain the cleaned intermediate layer of the target assembly.

In the invention, for the diffusion welding of the target material and the back plate, the bonding strength can be enhanced by using the intermediate layer when the atomic diffusion is difficult to carry out between the target material and the back plate, so that the surface cleanness and high purity of the intermediate layer are required to be ensured; according to the selection of the material of the intermediate layer, firstly, an organic solvent and water are adopted for ultrasonic cleaning to remove impurities, oil stains and the like on the surface of the intermediate layer, then, an oxidation layer on the surface of the intermediate layer is removed in a bubbling acid washing mode, then, the ultrasonic water washing is carried out to clean salt and acid remained on the surface, and finally, the intermediate layer with a clean surface is obtained after drying, so that the intermediate layer is suitable for being used as an intermediate connecting layer during diffusion welding of a target and a back plate and is beneficial to enhancing the welding strength of a target assembly; the method is simple to operate, low in cleaning cost and wide in application range.

The following technical solutions are preferred technical solutions of the present invention, but not limited to the technical solutions provided by the present invention, and technical objects and advantageous effects of the present invention can be better achieved and achieved by the following technical solutions.

In a preferred embodiment of the present invention, the material of the intermediate layer in the step (1) includes titanium.

Preferably, the shape of the intermediate layer of step (1) comprises a disc shape.

Preferably, the thickness of the intermediate layer in step (1) is 2.6-3.5 mm, such as 2.6mm, 2.8mm, 3mm, 3.2mm, 3.4mm or 3.5mm, but not limited to the recited values, and other values not recited in the range of the values are also applicable.

In the invention, the material of the intermediate layer needs to be selected according to the application environment, namely the material of the intermediate layer is selected according to the corresponding target and the back plate, and the requirement that the welding bonding property between the target and the back plate is stronger at least than the diffusion effect between the target and the back plate; the shape of the intermediate layer needs to be selected to be consistent with the shape of the welding surface of the target and the back plate.

As a preferred technical solution of the present invention, the organic solvent in step (1) comprises any one or a combination of at least two of isopropanol, ethanol or kerosene, and the combination is exemplified by the following typical but non-limiting examples: a combination of isopropanol and ethanol, a combination of ethanol and kerosene, a combination of isopropanol, ethanol and kerosene, and the like.

Preferably, the ultrasonic wave frequency in the ultrasonic cleaning in the step (1) is 42 to 60kHz, such as 42kHz, 45kHz, 48kHz, 50kHz, 52kHz, 55kHz, 57kHz or 60kHz, but not limited to the recited values, and other values not recited in the range of the recited values are also applicable.

Preferably, the temperature of the ultrasonic cleaning in the step (1) is 15 to 25 ℃, for example, 15 ℃, 16 ℃, 18 ℃, 20 ℃, 22 ℃, 24 ℃ or 25 ℃, but is not limited to the recited values, and other values not recited in the numerical range are also applicable.

Preferably, the ultrasonic cleaning in step (1) with the organic solvent and water is independently performed for 3 to 6min, such as 3min, 3.5min, 4min, 4.5min, 5min, 5.5min, or 6min, but not limited to the recited values, and other values not recited in the range of the values are also applicable.

In the invention, the ultrasonic cleaning is respectively carried out by adopting an organic solvent and water, and the surface impurities are fully cleaned by utilizing the vibration action of ultrasonic waves mainly aiming at the organic and inorganic impurities on the surface of the intermediate layer.

In a preferred embodiment of the present invention, the acid used in the bubble acid washing in step (2) includes nitric acid and/or hydrofluoric acid.

In the present invention, the pickling solution used for the bubble pickling is generally a mixed solution of an acid and water, and the concentration of the pickling solution is controlled by the use ratio of water, and a mixed solution of nitric acid, hydrofluoric acid and water is preferably selected.

Preferably, the temperature of the bubble acid washing in the step (2) is 30 to 35 ℃, for example, 30 ℃, 31 ℃, 32 ℃, 33 ℃, 34 ℃ or 35 ℃, but not limited to the recited values, and other values not recited in the range of the values are also applicable.

Preferably, the bubbling acid washing in step (2) is carried out for 1-3 min, such as 1min, 1.5min, 2min, 2.5min or 3min, but not limited to the recited values, and other values not recited in the range of the recited values are also applicable.

In the invention, an oxide layer is often formed on the surface of the normally used intermediate layer made of metal, and the existence of the oxide layer affects the diffusion performance of atoms during diffusion welding, so that the surface oxide layer needs to be removed, and the oxide is usually subjected to acid washing by adopting inorganic acid to convert the oxide into soluble salts.

As a preferable technical scheme of the invention, gas is introduced into the pickling solution in the bubbling pickling process in the step (2).

Preferably, the introduced gas comprises compressed air.

According to the invention, compressed air is introduced in the pickling process, so that the activity of the pickling solution can be effectively increased, and the washing rate of the surface oxide layer of the intermediate layer is increased.

Preferably, after the bubbling acid washing in the step (2) is finished, the intermediate layer is soaked in water for water washing.

Preferably, the soaking and water washing time is 4-6 min, such as 4min, 4.5min, 5min, 5.5min or 6min, but not limited to the recited values, and other values not recited in the range of the values are also applicable.

In a preferred embodiment of the present invention, the number of times of the ultrasonic water washing in step (3) is at least 1, for example, 1, 2, 3, or 4, preferably 2 to 3.

Preferably, the frequency of the ultrasonic wave in the ultrasonic water washing in the step (3) is 42 to 60kHz, such as 42kHz, 45kHz, 48kHz, 50kHz, 52kHz, 55kHz, 57kHz or 60kHz, but not limited to the recited values, and other values not recited in the range of the recited values are also applicable.

Preferably, the temperature of the ultrasonic washing in the step (3) is 15 to 25 ℃, for example, 15 ℃, 16 ℃, 18 ℃, 20 ℃, 22 ℃, 24 ℃ or 25 ℃, but is not limited to the recited values, and other values not recited in the range of the values are also applicable.

Preferably, the total time of the ultrasonic water washing in the step (3) is 10-20 min, such as 10min, 12min, 14min, 15min, 16min, 18min or 20min, but not limited to the enumerated values, and other non-enumerated values in the range of the enumerated values are also applicable.

In the invention, the acid washing is carried out again, so that the residual acid on the surface can be fully washed, and the possible inorganic salts can be removed, thereby ensuring the cleanness of the surface.

As a preferable technical scheme of the invention, the drying in the step (3) sequentially comprises blowing drying and vacuum drying.

Preferably, the purge drying purges the intermediate layer with a compressed gas.

Preferably, the compressed gas comprises an inert gas and/or nitrogen.

Preferably, the pressure of the compressed gas is 1 to 5kPa, for example, 1kPa, 2kPa, 3kPa, 4kPa, or 5kPa, but is not limited to the recited values, and other values not recited in the range of the recited values are also applicable.

Preferably, the time period of the purge drying is 4-6 min, such as 4min, 4.5min, 5min, 5.5min or 6min, but not limited to the recited values, and other values not recited in the range of the values are also applicable.

According to the invention, when the surface of the intermediate layer has more moisture, compressed gas is firstly adopted for blowing and drying, so that the blowing efficiency is high, the used time is short, and obvious water stain marks are prevented from being left on the surface of the intermediate layer.

In a preferred embodiment of the present invention, the temperature of the vacuum drying is 60 to 100 ℃, for example, 60 ℃, 70 ℃, 80 ℃, 90 ℃ or 100 ℃, but the temperature is not limited to the above-mentioned values, and other values not shown in the above-mentioned range are also applicable.

Preferably, the pressure of the vacuum drying is-0.09 to-0.1 MPa, for example, -0.09MPa, -0.092MPa, -0.094MPa, -0.096MPa, -0.098MPa or-0.1 MPa, but not limited to the values listed, and other values not listed in the range of the values are also applicable.

Preferably, the vacuum drying time is 40-90 min, such as 40min, 50min, 60min, 70min, 80min or 90min, but not limited to the recited values, and other values not recited in the range of the values are also applicable.

As a preferable technical scheme of the invention, the intermediate layer is detected and packaged after being cleaned.

Preferably, the testing comprises purity testing of the cleaned intermediate layer.

Preferably, the packaging is vacuum packaging of the cleaned intermediate layer.

As a preferable technical solution of the present invention, the cleaning method includes the steps of:

(1) sequentially carrying out ultrasonic cleaning on an intermediate layer to be cleaned by adopting an organic solvent and water, wherein the material of the intermediate layer comprises titanium, the thickness of the intermediate layer is 2.6-3.5 mm, the organic solvent comprises any one or a combination of at least two of isopropanol, ethanol or kerosene, the frequency of ultrasonic waves is 4.2-6 Hz during ultrasonic cleaning, the temperature is 15-25 ℃, and the time for ultrasonic cleaning by adopting the organic solvent and the water is independently 3-6 min;

(2) carrying out bubbling pickling on the intermediate layer treated in the step (1), wherein acid used in the bubbling pickling comprises nitric acid and/or hydrofluoric acid, the temperature of the bubbling pickling is 30-35 ℃, the time is 1-3 min, gas is introduced into a pickling solution in the bubbling pickling process, and after the bubbling pickling is finished, the intermediate layer is placed in water for soaking and washing for 4-6 min;

(3) and (3) carrying out ultrasonic washing on the intermediate layer treated in the step (2) again, wherein the frequency of the ultrasonic washing is at least 1 time, the frequency of the ultrasonic is 4.2-6 Hz, the temperature is 15-25 ℃, the total time is 10-20 min, then carrying out purging drying and vacuum drying in sequence, wherein compressed gas is adopted for purging the intermediate layer in the purging drying, the pressure of the compressed gas is 1-5 kPa, the purging drying time is 4-6 min, the vacuum drying temperature is 60-100 ℃, the pressure is-0.09-0.1 MPa, and the time is 40-90 min, so as to obtain the cleaned intermediate layer of the target component.

Compared with the prior art, the invention has the following beneficial effects:

(1) according to the method, the operations of ultrasonic cleaning, bubbling acid cleaning and ultrasonic water washing are sequentially adopted according to the material and surface stains of the intermediate layer, so that impurities, dirt, oil stains, oxide layers and the like on the surface of the intermediate layer are fully removed, the purity of the cleaned intermediate layer can reach more than 4N, the compactness and uniformity of a welding surface when the intermediate layer is used for diffusion welding are ensured, and the welding strength of the target assembly is improved;

(2) the method disclosed by the invention is simple to operate, low in cleaning cost, less in waste liquid amount and wide in application range.

Detailed Description

In order to better illustrate the present invention and facilitate the understanding of the technical solutions of the present invention, the present invention is further described in detail below. However, the following examples are only simple examples of the present invention and do not represent or limit the scope of the present invention, which is defined by the claims.

The embodiment of the invention provides a cleaning method of an intermediate layer of a target assembly, which comprises the following steps:

(1) sequentially adopting an organic solvent and water to carry out ultrasonic cleaning on the intermediate layer to be cleaned;

(2) carrying out bubbling acid washing on the intermediate layer treated in the step (1);

(3) and (3) carrying out ultrasonic washing on the intermediate layer processed in the step (2) again, and drying to obtain the cleaned intermediate layer of the target assembly.

The following are typical but non-limiting examples of the invention:

example 1:

the embodiment provides a cleaning method of an intermediate layer of a target assembly, which comprises the following steps:

(1) sequentially carrying out ultrasonic cleaning on an intermediate layer to be cleaned by adopting isopropanol and water, wherein the intermediate layer is made of titanium and is in a disc shape, the thickness of the intermediate layer is 3mm, the frequency of ultrasonic waves during ultrasonic cleaning is 50kHz, the temperature is 20 ℃, and the time for ultrasonic cleaning by adopting the isopropanol and the water is 5 min;

(2) carrying out bubbling pickling on the intermediate layer treated in the step (1), wherein a pickling solution used for the bubbling pickling is a mixed solution of nitric acid, hydrofluoric acid and water, the temperature of the bubbling pickling is 32 ℃, the time is 2min, compressed air is introduced into the pickling solution in the bubbling pickling process, and after the bubbling pickling is finished, the intermediate layer is placed in water to be soaked and washed for 5 min;

(3) and (3) carrying out ultrasonic washing on the intermediate layer treated in the step (2) again, wherein the ultrasonic washing is carried out for 3 times, the frequency of ultrasonic waves is 50kHz, the temperature is 20 ℃, the total time is 15min, then carrying out blowing drying and vacuum drying in sequence, wherein the blowing drying is carried out on the intermediate layer by adopting compressed nitrogen, the pressure of the compressed nitrogen is 3kPa, the time of blowing drying is 5min, the temperature of vacuum drying is 80 ℃, the pressure is-0.095 MPa, and the time is 60min, so as to obtain the cleaned intermediate layer of the target assembly.

Example 2:

the embodiment provides a cleaning method of an intermediate layer of a target assembly, which comprises the following steps:

(1) sequentially carrying out ultrasonic cleaning on an intermediate layer to be cleaned by adopting isopropanol and water, wherein the intermediate layer is made of titanium and is in a disc shape, the thickness of the intermediate layer is 2.6mm, the frequency of ultrasonic waves during ultrasonic cleaning is 42kHz, the temperature is 15 ℃, and the time for ultrasonic cleaning by adopting isopropanol and water is 6 min;

(2) carrying out bubbling pickling on the intermediate layer treated in the step (1), wherein a pickling solution used for the bubbling pickling is a mixed solution of nitric acid, hydrofluoric acid and water, the temperature of the bubbling pickling is 30 ℃, the time is 3min, compressed air is introduced into the pickling solution in the bubbling pickling process, and the intermediate layer is soaked in water and washed for 4 min;

(3) and (3) carrying out ultrasonic washing on the intermediate layer treated in the step (2) again, wherein the ultrasonic washing frequency is 2 times, the ultrasonic frequency is 42kHz, the temperature is 15 ℃, the total time is 20min, then carrying out purging drying and vacuum drying in sequence, wherein the purging drying adopts compressed nitrogen to purge the intermediate layer, the pressure of the compressed nitrogen is 5kPa, the purging drying time is 4min, the vacuum drying temperature is 60 ℃, the pressure is-0.1 MPa, and the time is 40min, so as to obtain the cleaned intermediate layer of the target assembly.

Example 3:

the embodiment provides a cleaning method of an intermediate layer of a target assembly, which comprises the following steps:

(1) sequentially carrying out ultrasonic cleaning on an intermediate layer to be cleaned by adopting ethanol and water, wherein the intermediate layer is made of titanium and is in a disc shape, the thickness of the intermediate layer is 3.5mm, the frequency of ultrasonic waves during ultrasonic cleaning is 60kHz, the temperature is 25 ℃, and the time for ultrasonic cleaning by adopting the ethanol and the water is 4 min;

(2) carrying out bubbling pickling on the intermediate layer treated in the step (1), wherein a pickling solution used in the bubbling pickling is a mixed solution of nitric acid and water, the temperature of the bubbling pickling is 35 ℃, the time is 1min, compressed air is introduced into the pickling solution in the bubbling pickling process, and the intermediate layer is soaked in water and washed for 6 min;

(3) and (3) carrying out ultrasonic washing on the intermediate layer treated in the step (2) again, wherein the ultrasonic washing frequency is 1 time, the ultrasonic frequency is 60kHz, the temperature is 25 ℃, the total time is 10min, then carrying out purging drying and vacuum drying in sequence, wherein the purging drying adopts compressed argon to purge the intermediate layer, the pressure of the compressed argon is 1kPa, the purging drying time is 6min, the vacuum drying temperature is 100 ℃, the pressure is-0.09 MPa, and the time is 90min, so as to obtain the cleaned intermediate layer of the target assembly.

Example 4:

the embodiment provides a cleaning method of an intermediate layer of a target assembly, which comprises the following steps:

(1) sequentially carrying out ultrasonic cleaning on an intermediate layer to be cleaned by adopting ethanol and water, wherein the intermediate layer is made of titanium and is in a disc shape, the thickness of the intermediate layer is 2.8mm, the frequency of ultrasonic waves during ultrasonic cleaning is 55kHz, the temperature is 18 ℃, and the time for ultrasonic cleaning by adopting the ethanol and the water is 3 min;

(2) carrying out bubbling pickling on the intermediate layer treated in the step (1), wherein a pickling solution used in the bubbling pickling is a mixed solution of hydrofluoric acid and water, the temperature of the bubbling pickling is 34 ℃, the time is 1.5min, compressed air is introduced into the pickling solution in the bubbling pickling process, and after the bubbling pickling is finished, the intermediate layer is placed in water to be soaked and washed for 4.5 min;

(3) and (3) carrying out ultrasonic washing on the intermediate layer treated in the step (2) again, wherein the ultrasonic washing is carried out for 3 times, the frequency of ultrasonic waves is 55kHz, the temperature is 18 ℃, the total time is 18min, then carrying out purging drying and vacuum drying in sequence, wherein compressed argon is used for purging the intermediate layer in the purging drying, the pressure of the compressed argon is 2kPa, the purging drying time is 5.5min, the vacuum drying temperature is 70 ℃, the pressure is-0.092 MPa, and the time is 75min, so as to obtain the cleaned intermediate layer of the target assembly.

Example 5:

the embodiment provides a cleaning method of an intermediate layer of a target assembly, which comprises the following steps:

(1) sequentially carrying out ultrasonic cleaning on an intermediate layer to be cleaned by adopting kerosene and water, wherein the intermediate layer is made of titanium and is square, the thickness of the intermediate layer is 3.2mm, the frequency of the ultrasonic wave during ultrasonic cleaning is 45kHz, the temperature is 22 ℃, and the time for ultrasonic cleaning by adopting the kerosene and the water is 4.5 min;

(2) carrying out bubbling pickling on the intermediate layer treated in the step (1), wherein a pickling solution used in the bubbling pickling is a mixed solution of nitric acid, hydrofluoric acid and water, the temperature of the bubbling pickling is 30 ℃, the time is 2.5min, compressed air is introduced into the pickling solution in the bubbling pickling process, and the intermediate layer is soaked in water and washed for 5.5 min;

(3) and (3) carrying out ultrasonic washing on the intermediate layer treated in the step (2) again, wherein the ultrasonic washing frequency is 2 times, the ultrasonic frequency is 45kHz, the temperature is 22 ℃, the total time is 14min, then carrying out purging drying and vacuum drying in sequence, wherein the purging drying adopts compressed nitrogen to purge the intermediate layer, the pressure of the compressed nitrogen is 4kPa, the purging drying time is 4.5min, the vacuum drying temperature is 90 ℃, the pressure is-0.098 MPa, and the time is 50min, so as to obtain the cleaned intermediate layer of the target assembly.

In examples 1 to 5, the method is used to clean the intermediate layer of the target assembly, and after the cleaning is completed, the surface of the intermediate layer is clean, no stain or watermark remains, no oxide layer remains, a complete cleaning effect is achieved, and the purity of the intermediate layer can be more than 4N.

Comparative example 1:

this comparative example provides a cleaning method of an intermediate layer of a target assembly, which is referred to the method of example 1, except that: the bubble acid washing in the step (2) is not included.

In the comparative example, as the bubbling acid washing is not arranged in the cleaning method of the middle layer, the oxide layer on the surface of the middle layer is difficult to remove only by the ultrasonic washing of the organic solvent and water, and the compactness of the oxide layer can greatly influence the diffusion of atoms during diffusion welding, so that the middle layer cannot be used for enhancing the welding bonding property, and even the welding strength is reduced.

According to the method, the operations of ultrasonic cleaning, bubbling acid cleaning and ultrasonic washing are sequentially adopted according to the material and surface stains of the intermediate layer, so that impurities, dirt, oil stains, an oxide layer and the like on the surface of the intermediate layer are fully removed, the purity of the cleaned intermediate layer can reach more than 4N, the compactness and uniformity of a welding surface when the intermediate layer is used for diffusion welding are ensured, and the welding strength of the target assembly is improved; the method is simple to operate, low in cleaning cost, less in waste liquid amount and wide in application range.

The applicant states that the present invention is illustrated in detail by the above examples, but the present invention is not limited to the above detailed methods, i.e. it is not meant that the present invention must rely on the above detailed methods for its implementation. It will be apparent to those skilled in the art that any modification, equivalent substitution of the process of the invention and addition of ancillary operations, selection of specific means, etc., of the present invention are within the scope and disclosure of the invention.