阅读说明：本技术 一种铌靶材与铜背板的钎焊方法 (Method for brazing niobium target and copper back plate ) 是由 姚力军 边逸军 潘杰 王学泽 陈石 廖培君 于 2021-08-19 设计创作，主要内容包括：本发明提供了一种铌靶材与铜背板的钎焊方法,包括：在铌靶材的焊接面依次进行喷砂预处理和化学镀镍,随后采用钎料分别浸润铌靶材与铜背板,再对浸润处理后的铌靶材的焊接面与铜背板进行焊接。本发明实现了铌靶材与铜背板的焊接,仅在铌靶材表面进行喷砂和镀镍处理,简化了工艺流程,降低了工作复杂度,且镀镍处理改善了铌靶材以及铜背板的焊接性能,使铌靶材与铜背板能够实现可靠结合；将铜丝设置于铌靶材与铜背板的焊接面之间,有效保留了靶材和背板焊接面间的焊料,提高了铌靶材与铜背板的结合强度。(The invention provides a method for brazing a niobium target and a copper back plate, which comprises the following steps: and sequentially carrying out sand blasting pretreatment and chemical nickel plating on the welding surface of the niobium target material, then respectively infiltrating the niobium target material and the copper back plate by using brazing filler metal, and then welding the welding surface of the niobium target material after infiltration treatment and the copper back plate. The welding method realizes the welding of the niobium target and the copper back plate, only carries out sand blasting and nickel plating treatment on the surface of the niobium target, simplifies the process flow, reduces the working complexity, improves the welding performance of the niobium target and the copper back plate through the nickel plating treatment, and ensures that the niobium target and the copper back plate can be reliably combined; the copper wire is arranged between the welding surfaces of the niobium target and the copper back plate, so that the welding flux between the target and the welding surface of the back plate is effectively reserved, and the bonding strength of the niobium target and the copper back plate is improved.)

1. A method of brazing a niobium target to a copper backing plate, the method comprising:

and sequentially carrying out sand blasting pretreatment and chemical nickel plating on the welding surface of the niobium target material, then respectively infiltrating the niobium target material and the copper back plate by using brazing filler metal, and then welding the welding surface of the niobium target material after infiltration treatment and the copper back plate.

2. The brazing method according to claim 1, comprising the steps of:

the method comprises the following steps of (I) spraying sand grains to a welding surface of a niobium target to form a rough sand blasting surface;

(II) activating the niobium target material in the step (I) by adopting acid liquor, and then placing the niobium target material in nickel plating solution to form a nickel plating layer on the sand blasting surface;

(III) respectively placing the copper back plate and the niobium target material on a heating platform for heating, simultaneously covering the brazing filler metal on the surfaces of the copper back plate and the niobium target material, infiltrating the copper back plate and the niobium target material after the brazing filler metal is melted, and respectively forming brazing filler metal layers on the surfaces of one sides of the welding surfaces of the copper back plate and the niobium target material;

and (IV) placing a copper wire on the surface of the brazing filler metal layer of the copper back plate in the step (III), placing the niobium target material on the copper wire, applying pressure, and cooling to finish brazing.

3. The brazing method according to claim 2, wherein in the step (I), the sand grains are 46# white corundum;

preferably, the pressure of the injection is 0.4-0.45 MPa;

preferably, the roughness of the sandblasted surface is 4-8 μm.

4. The brazing method according to claim 2 or 3, wherein in the step (II), the acid solution is a mixed acid;

preferably, the mixed acid comprises a mixed acid solution of hydrofluoric acid and nitric acid;

preferably, the volume ratio of hydrofluoric acid to nitric acid to water in the mixed acid liquid is (0.8-1.2): (2-4): (3-5);

preferably, the activation time is 2-3 min.

5. The brazing method according to any one of claims 2 to 4, wherein in the step (II), the nickel plating solution is placed for 30 to 50 min;

preferably, the type of the nickel plating solution includes any one of a sulfate type, a chloride type, an sulfamate type, a citrate type, or an ammonia borate type or a combination of at least two of them.

6. The brazing method according to any one of claims 2 to 5, wherein the step (II) further comprises washing the niobium target after activation;

preferably, the washing is performed using pure water.

7. The brazing method according to any one of claims 2 to 6, wherein in the step (III), the temperature of the brazing filler metal after heating is 160 to 190 ℃;

preferably, the solder comprises indium solder;

preferably, the infiltration is ultrasonic infiltration;

preferably, the frequency of the ultrasonic wave is 20-50 kHz;

preferably, the vibration amplitude of the ultrasonic waves is 5-50 μm;

preferably, one side of the brazing filler metal layer of the niobium target is placed facing the copper wire.

8. The brazing method according to any one of claims 2 to 7, wherein in the step (III), a circle of adhesive tape is pasted to the side of the non-welding surface of the copper back plate before heating;

preferably, the adhesive tape is 1-2 mm higher than the solder layer;

preferably, the adhesive tape is a temperature-resistant adhesive tape.

9. The brazing method according to any one of claims 2 to 8, wherein in the step (IV), the length of the copper wire is smaller than that of the welding surface;

preferably, the diameter of the copper wire is 0.2-0.5 mm.

10. The brazing method according to any one of claims 2 to 9, wherein in the step (iv), the pressing is performed by placing a compact on the surface of the niobium target;

preferably, the weight of the briquettes is 30-60 kg;

preferably, in step (iv), the copper back plate is cooled together with the heating platform;

preferably, the adhesive tape on the side surface of the copper back plate is removed after cooling.

Technical Field

The invention belongs to the technical field of sputtering targets, relates to a brazing method of a target and a back plate, and particularly relates to a brazing method of a niobium target and a copper back plate.

Background

Sputtering is one of the main techniques for preparing thin film materials, when charged particles bombard the surface of a solid material, surface atom collision occurs and energy and momentum transfer is generated, so that bombarded material atoms escape from the surface and are deposited on a substrate, and the bombarded solid is a raw material for preparing a deposited thin film by a sputtering method and is generally called as a sputtering target material. Because the strength of the sputtering target is different, in the practical application process, the sputtering target and the back plate need to be bound to form a target assembly. The backing plate provides support for the sputtering target while conducting heat, and the sputtering target and the backing plate are generally bonded by welding. Because the working environment of the target assembly in the sputtering process is severe, if the welding combination degree between the target and the back plate in the target assembly is low, the target deforms and cracks under the heated condition, and even falls off from the back plate.

Brazing refers to a welding method in which brazing filler metal lower than the melting point of a weldment and the weldment are heated to the melting temperature of the brazing filler metal at the same time, and then the liquid brazing filler metal is used for filling gaps of solid workpieces to connect metals. Brazing is divided into brazing and soldering according to the melting point of the brazing filler metal. The existing brazing method for the target and the back plate cannot effectively retain the welding flux between the welding surfaces of the target and the back plate, so that the welding bonding rate and the welding bonding strength are difficult to ensure.

CN101176960A discloses a method for connecting a metal target and a target holder, comprising the following steps: (1) respectively processing a middle arc convex surface and a middle arc concave surface for combination at the corresponding contact parts of the target material and the target holder; (2) cleaning the machining table top of the target material and the target holder for oil removal, acid pickling and the like, and drying; (3) heating the target holder to the liquidus line of the brazing material of 30-50 ℃, and uniformly coating the brazing material in the concave surface of the target holder; (4) the convex surface of the target material is extruded into the concave surface of the target holder under the axial pressure; (5) during the extrusion process, the brazing material on the concave surface of the target holder fills each part of the joint surface when melting and flowing, and the residual air is removed through the exhaust passage.

CN111570957A discloses a brazing method of a copper back plate assembly, S1, preparing the copper back plate assembly and a stainless steel water nozzle, and treating the surface of the copper back plate assembly to achieve the effect of completely removing an oxide film on the surface; s2, electroplating the surface of the stainless steel water nozzle; s3, assembling the waterway substrate above the substrate to form a brazing seam E, and filling metal brazing filler metal around the brazing seam E; s4, assembling a water inlet of the stainless steel water nozzle at the position of the base clamping groove to form a brazing seam A and a brazing seam B, and filling metal brazing filler metal around the brazing seam A and the brazing seam B; s5, assembling the water outlet of the stainless steel water nozzle and the waterway substrate to form a brazing seam C and a brazing seam D, and filling metal brazing filler metal at the positions of the brazing seam C and the brazing seam D.

CN103737140A discloses a method for binding an ITO target material and a copper back plate, in which the copper back plate is fixed on a heating table, and the ITO target material is placed on the copper back plate; heating the copper back plate, and attaching the ITO target to the copper back plate through brazing; and placing a balancing weight on the surface of the ITO target far away from the copper back plate, and taking down the balancing weight after the ITO target is cooled. The heating steps are specifically as follows: heating the copper back plate from room temperature to 50 ℃, and keeping the temperature of 50 ℃ for 5 minutes; then heating from 50 ℃ to 80 ℃, and keeping the temperature at 80 ℃ for 5 minutes; then heating from 80 ℃ to 110 ℃, and keeping the temperature at 110 ℃ for 5 minutes; then heating from 110 ℃ to 140 ℃, and keeping the temperature at 140 ℃ for 5 minutes; further heating the copper back plate from 140 ℃ to 170-180 ℃, and maintaining the temperature of the copper back plate at 170-180 ℃.

The traditional brazing method is used for welding various semiconductor targets, such as tungsten targets, titanium targets, molybdenum targets, chromium targets, nickel targets, silver targets, ITO targets and the like, a copper back plate needs to be subjected to sand blasting and nickel plating treatment, the welding structure is complex, the complexity of the process is increased, and the welding bonding rate and the welding bonding strength are difficult to guarantee because welding materials between the target and the welding surface of the back plate cannot be effectively reserved.

The existing welding method has no disclosed example about the brazing method of the niobium target and the copper back plate, so how to braze the niobium target and the copper back plate and improve the bonding law and the welding bonding strength of the target and the back plate in the brazing process are important to research.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide the brazing method for the niobium target and the copper back plate, which has the advantages of simple process, easiness in operation, high welding bonding law and high welding bonding strength.

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

the invention provides a brazing method of a niobium target and a copper back plate, which comprises the following steps:

and sequentially carrying out sand blasting pretreatment and chemical nickel plating on the welding surface of the niobium target material, then respectively infiltrating the niobium target material and the copper back plate by using brazing filler metal, and then welding the infiltrated niobium target material and the copper back plate.

As a preferred embodiment of the present invention, the brazing method comprises the steps of:

the method comprises the following steps of (I) spraying sand grains to a welding surface of a niobium target to form a rough sand blasting surface;

(II) activating the niobium target material in the step (I) by adopting acid liquor, and then placing the niobium target material in nickel plating solution to form a nickel plating layer on the sand blasting surface;

(III) respectively placing the copper back plate and the niobium target material on a heating platform for heating, simultaneously covering the brazing filler metal on the surfaces of the copper back plate and the niobium target material, infiltrating the copper back plate and the niobium target material after the brazing filler metal is melted, and respectively forming brazing filler metal layers on the surfaces of one sides of the welding surfaces of the copper back plate and the niobium target material;

and (IV) placing a copper wire on the surface of the brazing filler metal layer of the copper back plate in the step (III), placing the niobium target material on the copper wire, applying pressure, and cooling to finish brazing.

In a preferred technical scheme of the invention, in the step (I), the sand grains are 46# white corundum.

Preferably, the pressure of the injection is 0.4 to 0.45MPa, for example, 0.4MPa, 0.41MPa, 0.42MPa, 0.43MPa, 0.44MPa or 0.45MPa, but is not limited to the values listed, and other values not listed in the range of the values are also applicable.

Preferably, the roughness of the blasted surface is 4 to 8 μm, and may be, for example, 4 μm, 4.2 μm, 4.5 μm, 4.8 μm, 5 μm, 5.3 μm, 5.5 μm, 5.8 μm, 6 μm, 6.2 μm, 6.5 μm, 6.8 μm, 7 μm, 7.3 μm, 7.5 μm, 7.8 μm or 8 μm, but is not limited to the recited values, and other values not recited in this range of values are equally applicable. According to the invention, the surface of the niobium target is subjected to sand blasting, so that the roughness of the welding surface of the niobium target and the copper back plate is improved, and the bonding degree during subsequent nickel plating treatment is improved.

As a preferable technical scheme of the invention, the acid solution is mixed acid.

Preferably, the mixed acid comprises a mixed acid solution of hydrofluoric acid and nitric acid. According to the method, the mixed acid of hydrofluoric acid and nitric acid is adopted to activate the welding surface of the niobium target material, so that the surface oxide layer can be removed.

Preferably, the volume ratio of hydrofluoric acid to nitric acid to water in the mixed acid liquid is (0.8-1.2): (2-4): (3 to 5) may be (0.8:2:3), (1:2:3), (1.2:2:3), (0.8:3:3), (1.2:3:3), (1:3:4), (0.8:2:4), (1:2:4), (1.2:2:5), (1:2:5) or (1.2:4:5), for example, but the numerical values are not limited to the enumerated values, and other numerical values not enumerated within the numerical value range are also applicable.

Preferably, the activation time is 2-3 min, such as 2min, 2.1min, 2.2min, 2.3min, 2.4min, 2.5min, 2.6min, 2.7min, 2.8min, 2.9min or 3min, but not limited to the recited values, and other values not recited in the range of values are equally applicable.

In a preferred embodiment of the present invention, in the step (ii), the nickel plating solution is placed for 30-50 min, for example, 30min, 31min, 32min, 33min, 34min, 35min, 36min, 37min, 38min, 39min, 40min, 41min, 42min, 43min, 44min, 45min, 46min, 47min, 48min, 49min or 50min, but the method is not limited to the values listed, and other values not listed in the range of the values are also applicable.

Preferably, the type of the nickel plating solution includes any one of a sulfate type, a chloride type, an sulfamate type, a citrate type, or an ammonia borate type or a combination of at least two of them.

In a preferred embodiment of the present invention, the step (ii) further comprises washing the niobium target after activation.

Preferably, the washing is performed using pure water.

In a preferred embodiment of the present invention, in the step (III), the temperature of the solder after heating is 160 to 190 ℃, and may be, for example, 160 ℃, 162 ℃, 165 ℃, 168 ℃, 170 ℃, 173 ℃, 175 ℃, 177 ℃, 178 ℃, 180 ℃, 182 ℃, 185 ℃, 188 ℃ or 190 ℃, but the temperature is not limited to the above-mentioned values, and other values not listed in the above-mentioned range of values are also applicable.

Preferably, the solder comprises indium solder.

Preferably, the infiltration is ultrasonic infiltration.

Preferably, the frequency of the ultrasonic wave is 20kHz to 50kHz, for example, 20kHz, 23kHz, 25kHz, 27kHz, 30kHz, 32kHz, 35kHz, 38kHz, 40kHz, 42kHz, 45kHz, 48kHz or 50kHz, but is not limited to the recited values, and other values not recited in the range of the values are also applicable.

Preferably, the vibration amplitude of the ultrasonic wave is 5 to 50 μm, and may be, for example, 5 μm, 8 μm, 10 μm, 12 μm, 15 μm, 20 μm, 23 μm, 25 μm, 27 μm, 30 μm, 32 μm, 35 μm, 38 μm, 40 μm, 42 μm, 45 μm, 48 μm or 50 μm, but is not limited to the values listed, and other values not listed in the numerical range are also applicable.

Preferably, one side of the brazing filler metal layer of the niobium target is placed facing the copper wire.

In a preferred embodiment of the present invention, in step (iii), a circle of adhesive tape is adhered to the side surface of the non-bonding surface of the copper back plate before heating.

Preferably, the adhesive tape is 1-2 mm higher than the solder layer, such as 1mm, 1.2mm, 1.5mm, 1.8mm or 2mm, but not limited to the values listed, and other values not listed in the range of the values are also applicable.

Preferably, the adhesive tape is a temperature-resistant adhesive tape. The side surface of the non-welding surface of the copper back plate is provided with the adhesive tape, the non-welding surface is shielded, then the welding flux is placed on the welding surface of the copper back plate and heated, and the molten welding flux is used for carrying out infiltration treatment.

As a preferable technical scheme of the invention, in the step (IV), the length of the copper wire is smaller than that of the welding surface.

Preferably, the diameter of the copper wire is 0.2-0.5 mm, such as 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm or 0.5mm, but not limited to the recited values, and other values not recited in the range of values are also applicable.

It should be noted that, in the invention, the copper wire is arranged between the welding surfaces of the niobium target and the copper back plate, the solder is uniformly distributed under the support of the copper wire, and a solder layer with a certain thickness is formed after cooling, so that the target and the back plate are welded together.

In a preferred embodiment of the present invention, in the step (iv), the pressing is performed by placing a compact on the surface of the niobium target.

Preferably, the briquette has a weight of 30 to 60kg, and may be, for example, 30kg, 32kg, 33kg, 35kg, 36kg, 38kg, 40kg, 42kg, 43kg, 45kg, 48kg, 50kg, 52kg, 55kg, 56kg, 57kg, 58kg or 60kg, but is not limited to the recited values, and other values not recited in the numerical range are also applicable.

Preferably, in step (iv), the copper back plate is cooled together with the heating platform. It should be noted that, in the present invention, the copper back plate and the heating platform are cooled together, so that air can be prevented from entering the welding surface and local shrinkage cavity can be prevented.

Preferably, the adhesive tape on the side surface of the copper back plate is removed after cooling.

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

according to the method for brazing the niobium target and the copper back plate, sand blasting and nickel plating are only carried out on the surface of the niobium target, so that the process flow is simplified, the working complexity is reduced, the roughness of the welding surface of the niobium target and the copper back plate is improved through sand blasting on the surface of the niobium target, and the bonding strength of a nickel layer and the welding surface is improved during subsequent nickel plating; the nickel plating treatment improves the welding performance of the niobium target and the copper back plate, so that the niobium target and the copper back plate can be reliably combined, and the combination rate and the combination strength are improved; the copper wires are arranged between the welding surfaces of the niobium target and the copper back plate and are uniformly distributed under the support of the copper wires, so that the welding flux between the target and the welding surface of the back plate is effectively reserved, the bonding strength of the niobium target and the copper back plate is improved, and the requirement of long-term stable use of the target assembly is met.

Drawings

Fig. 1 is a schematic structural view of a target assembly according to an embodiment of the present invention.

Wherein, 1-niobium target material; 2-a copper backplane; 3-a copper wire; 4-brazing filler metal layer; 5-adhesive tape.

Detailed Description

The technical scheme of the invention is further explained by the specific implementation mode in combination with the attached drawings.

In one embodiment, the present invention provides a brazing method of a niobium target 1 and a copper backing plate 2, the brazing method comprising:

and (2) sequentially carrying out sand blasting pretreatment and chemical nickel plating on the welding surface of the niobium target material 1, then respectively infiltrating the niobium target material 1 and the copper back plate 2 with brazing filler metal, and then welding the infiltrated niobium target material 1 and the copper back plate 2.

The method specifically comprises the following steps:

spraying sand grains to the welding surface of a niobium target material 1, wherein the spraying pressure is 0.4-0.45 MPa, and a sand blasting surface with the roughness of 4-8 mu m is formed;

(II) adopting a volume ratio of (0.8-1.2): (2-4): (3-5) activating the niobium target 1 in the step (I) for 2-3 min by using a mixed acid solution of hydrofluoric acid, nitric acid and water, cleaning the niobium target 1, and then placing the niobium target 1 in a nickel plating solution for 30-50 min to form a nickel plating layer on the sandblasted surface, wherein the type of the nickel plating solution comprises any one or a combination of at least two of a sulfate type, a chloride type, an aminosulfonate type, a citrate type or an ammonia borate type;

(III) as shown in fig. 1, a circle of adhesive tape 5 is pasted along the side face of the non-welding face of the copper back plate 2, the height of the adhesive tape 5, which is higher than that of the solder layer 4, is 1-2 mm, then the copper back plate 2 and the niobium target material 1 are respectively placed on a heating platform to be heated, meanwhile, the solder is covered on the surfaces of the copper back plate 2 and the niobium target material 1, the copper back plate 2 and the niobium target material 1 are infiltrated after the solder is melted, the solder layers 4 are respectively formed on the surfaces of the copper back plate 2 and the niobium target material 1, the temperature of the heated solder is 160-190 ℃, the solder can be infiltrated by using indium solder, the frequency of the ultrasonic wave is 20-50 kHz, and the vibration amplitude is 5-50 μm.

(IV) placing a copper wire 3 with the diameter of 0.2-0.5 mm on the surface of the brazing filler metal layer 4 of the copper back plate 2 in the step (III), placing one side of the brazing filler metal layer 4 of the niobium target 1 on the copper back plate 2 facing the copper wire 3, placing a pressing block with the weight of 30-60 kg on the surface of the niobium target 1, cooling the copper back plate 2 along with a heating platform, removing the adhesive tape 5, and completing brazing to obtain the target assembly.

Example 1

The embodiment provides a brazing method for a niobium target 1 and a copper back plate 2, which comprises the following steps:

and (2) sequentially carrying out sand blasting pretreatment and chemical nickel plating on the welding surface of the niobium target material 1, then respectively infiltrating the niobium target material 1 and the copper back plate 2 with brazing filler metal, and then welding the infiltrated niobium target material 1 and the copper back plate 2.

The method specifically comprises the following steps:

spraying No. 46 white corundum to the welding surface of a niobium target material 1, wherein the spraying pressure is 0.45MPa, and a sand blasting surface with the roughness of 6 mu m is formed;

(II) adopting a volume ratio of 1:3:4, activating the niobium target 1 in the step (I) for 3min by using mixed acid liquid of hydrofluoric acid, nitric acid and water, taking out the niobium target 1, cleaning the niobium target 1 by using pure water, and then placing the niobium target 1 in sulfate type nickel plating solution for 50min to form a nickel plating layer on the sand blasting surface;

(III) a circle of adhesive tape 5 is adhered to the side face of the non-welding face of the copper back plate 2, the height of the adhesive tape 5, which is 1mm higher than that of the solder layer 4, of the copper back plate 2 and the niobium target material 1 are respectively placed on a heating platform to be heated, meanwhile, the indium solder is covered on the surfaces of the copper back plate 2 and the niobium target material 1, the copper back plate 2 and the niobium target material 1 are infiltrated by ultrasonic waves after the indium solder is melted, the solder layers 4 are respectively formed on the surfaces of the copper back plate 2 and the niobium target material 1, the temperature of the heated indium solder is 180 ℃, the frequency of the ultrasonic waves is 40kHz, and the vibration amplitude is 20 microns.

(IV) placing a copper wire 3 with the diameter of 0.3mm on the surface of the brazing filler metal layer 4 of the copper back plate 2 in the step (III), placing one side of the brazing filler metal layer 4 of the niobium target 1 facing the copper wire 3 on the copper back plate 2, placing a pressing block with the weight of 50kg on the surface of the niobium target 1, cooling the copper back plate 2 along with the heating platform, taking out the temperature-resistant adhesive tape 5, and completing brazing.

Example 2

The embodiment provides a brazing method for a niobium target 1 and a copper back plate 2, which comprises the following steps:

and (2) sequentially carrying out sand blasting pretreatment and chemical nickel plating on the welding surface of the niobium target material 1, then respectively infiltrating the niobium target material 1 and the copper back plate 2 with brazing filler metal, and then welding the infiltrated niobium target material 1 and the copper back plate 2.

The method specifically comprises the following steps:

spraying No. 46 white corundum to the welding surface of a niobium target material 1, wherein the spraying pressure is 0.45MPa, and a sand blasting surface with the roughness of 8 mu m is formed;

(II) adopting a volume ratio of 1: 4: 4, activating the niobium target 1 in the step (I) for 3min by using mixed acid liquor of hydrofluoric acid, nitric acid and water, taking out the niobium target 1, cleaning the niobium target 1 by using pure water, and then placing the niobium target 1 in chloride type nickel plating solution for 45min to form a nickel plating layer on the sand blasting surface;

(III) a circle of adhesive tape 5 is adhered to the side face of the non-welding face of the copper back plate 2, the height of the adhesive tape 5, which is 1mm higher than that of the solder layer 4, of the copper back plate 2 and the niobium target material 1 are respectively heated, meanwhile, the indium solder is covered on the surfaces of the copper back plate 2 and the niobium target material 1, the copper back plate 2 and the niobium target material 1 are infiltrated by ultrasonic waves after the indium solder is melted, the solder layers 4 are respectively formed on the surfaces of the copper back plate 2 and the niobium target material 1, the temperature of the heated indium solder is 190 ℃, the frequency of the ultrasonic waves is 30kHz, and the vibration amplitude is 10 mu m.

(IV) placing a copper wire 3 with the diameter of 0.3mm on the surface of the brazing filler metal layer 4 of the copper back plate 2 in the step (III), placing one side of the brazing filler metal layer 4 of the niobium target 1 on the copper back plate 2 facing the copper wire 3, placing a pressing block with the weight of 50kg on the surface of the niobium target 1, cooling the copper back plate 2 along with the heating platform, taking out the temperature-resistant adhesive tape 5, and completing brazing.

Example 3

The embodiment provides a brazing method for a niobium target 1 and a copper back plate 2, which comprises the following steps:

and (2) sequentially carrying out sand blasting pretreatment and chemical nickel plating on the welding surface of the niobium target material 1, then respectively infiltrating the niobium target material 1 and the copper back plate 2 with brazing filler metal, and then welding the infiltrated niobium target material 1 and the copper back plate 2.

The method specifically comprises the following steps:

spraying No. 46 white corundum to the welding surface of a niobium target material 1, wherein the spraying pressure is 0.4MPa, and a sand blasting surface with the roughness of 5 mu m is formed;

(II) adopting a volume ratio of 0.8:3:3, activating the niobium target 1 in the step (I) for 2min by using mixed acid liquid of hydrofluoric acid, nitric acid and water, cleaning the niobium target 1 by using pure water after removing, and then placing the niobium target 1 in sulfamate type nickel plating solution for 40min to form a nickel plating layer on the sand blasting surface;

(III) a circle of adhesive tape 5 is adhered to the side face of the non-welding face of the copper back plate 2, the height of the adhesive tape 5, which is higher than that of the solder layer 4, is 2mm, then the copper back plate 2 and the niobium target material 1 are respectively placed on a heating platform to be heated, meanwhile, the indium solder is covered on the surfaces of the copper back plate 2 and the niobium target material 1, the copper back plate 2 and the niobium target material 1 are infiltrated by ultrasonic waves after the indium solder is melted, the solder layers 4 are respectively formed on the surfaces of the copper back plate 2 and the niobium target material 1, the temperature of the heated indium solder is 170 ℃, the frequency of the ultrasonic waves is 25kHz, and the vibration amplitude is 15 mu m.

(IV) placing a copper wire 3 with the diameter of 0.2mm on the surface of the brazing filler metal layer 4 of the copper back plate 2 in the step (III), placing one side of the brazing filler metal layer 4 of the niobium target 1 on the copper back plate 2 facing the copper wire 3, placing a pressing block with the weight of 30kg on the surface of the niobium target 1, cooling the copper back plate 2 along with the heating platform, taking out the temperature-resistant adhesive tape 5, and completing brazing.

Example 4

The embodiment provides a brazing method for a niobium target 1 and a copper back plate 2, which comprises the following steps:

and (2) sequentially carrying out sand blasting pretreatment and chemical nickel plating on the welding surface of the niobium target material 1, then respectively infiltrating the niobium target material 1 and the copper back plate 2 with brazing filler metal, and then welding the infiltrated niobium target material 1 and the copper back plate 2.

The method specifically comprises the following steps:

spraying No. 46 white corundum to the welding surface of a niobium target material 1, wherein the spraying pressure is 0.43MPa, and a sand blasting surface with the roughness of 4 mu m is formed;

(II) adopting a volume ratio of 1.2:4:5, activating the niobium target 1 in the step (I) for 2.5min by using mixed acid liquor of hydrofluoric acid, nitric acid and water, taking out the niobium target 1, cleaning the niobium target 1 by using pure water, and then placing the niobium target 1 in a citrate type nickel plating solution for 30min to form a nickel plating layer on the sand blasting surface;

(III) a circle of adhesive tape 5 is adhered to the side face of the non-welding face of the copper back plate 2, the height of the adhesive tape 5, which is 1mm higher than that of the solder layer 4, of the copper back plate 2 and the niobium target material 1 are respectively placed on a heating platform to be heated, meanwhile, the indium solder is covered on the surfaces of the copper back plate 2 and the niobium target material 1, the copper back plate 2 and the niobium target material 1 are infiltrated by ultrasonic waves after the indium solder is melted, the solder layers 4 are respectively formed on the surfaces of the copper back plate 2 and the niobium target material 1, the temperature of the heated indium solder is 160 ℃, the frequency of the ultrasonic waves is 20kHz, and the vibration amplitude is 5 mu m.

(IV) placing a copper wire 3 with the diameter of 0.42mm on the surface of the brazing filler metal layer 4 of the copper back plate 2 in the step (III), placing one side of the brazing filler metal layer 4 of the niobium target 1 on the copper back plate 2 facing the copper wire 3, placing a pressing block with the weight of 30kg on the surface of the niobium target 1, cooling the copper back plate 2 along with the heating platform, taking out the temperature-resistant adhesive tape 5, and completing brazing.

Example 5

Spraying No. 46 white corundum to the welding surface of a niobium target material 1, wherein the spraying pressure is 0.45MPa, and a sand blasting surface with the roughness of 7 mu m is formed;

(II) adopting a volume ratio of 1:2:3, activating the niobium target 1 in the step (I) for 2min by using mixed acid liquid of hydrofluoric acid, nitric acid and water, taking out the niobium target 1, cleaning the niobium target 1 by using pure water, and then placing the niobium target 1 in ammonia borate type nickel plating solution for 35min to form a nickel plating layer on the sand blasting surface;

(III) a circle of adhesive tape 5 is adhered to the side face of the non-welding face of the copper back plate 2, the height of the adhesive tape 5, which is 1mm higher than that of the solder layer 4, of the copper back plate 2 and the niobium target material 1 are respectively placed on a heating platform to be heated, meanwhile, the indium solder is covered on the surfaces of the copper back plate 2 and the niobium target material 1, the copper back plate 2 and the niobium target material 1 are infiltrated by ultrasonic waves after the indium solder is melted, the solder layers 4 are respectively formed on the surfaces of the copper back plate 2 and the niobium target material 1, the temperature of the heated indium solder is 175 ℃, the frequency of the ultrasonic waves is 35kHz, and the vibration amplitude is 50 microns.

(IV) placing a copper wire 3 with the diameter of 0.3mm on the surface of the brazing filler metal layer 4 of the copper back plate 2 in the step (III), placing one side of the brazing filler metal layer 4 of the niobium target 1 on the copper back plate 2 facing the copper wire 3, placing a pressing block with the weight of 30kg on the surface of the niobium target 1, cooling the copper back plate 2 along with the heating platform, taking out the temperature-resistant adhesive tape 5, and completing brazing.

Example 6

The present example differs from example 1 in that in step (ii), the cleaned niobium target 1 is taken out and placed in a mixed nickel plating solution of a sulfate type and a chloride type, and a nickel plating layer is formed on the blasted surface.

Example 7

The difference between this example and example 2 is that in step (ii), the cleaned niobium target 1 is taken out and placed in a mixed nickel plating solution of a chloride type and an sulfamate type, and a nickel plating layer is formed on the blasted surface.

Example 8

The difference between this example and example 3 is that in step (ii), the cleaned niobium target 1 is taken out and placed in a mixed nickel plating solution of an sulfamate type and a citrate type, and a nickel plating layer is formed on the blasted surface.

Example 9

The present example differs from example 4 in that in step (ii), the cleaned niobium target 1 is taken out and placed in a mixed nickel plating solution of a citrate type and an ammonia borate type, and a nickel plating layer is formed on the blasted surface.

Example 10

This example differs from example 1 in that in step (ii), the niobium target 1 is activated with hydrofluoric acid.

Example 11

This example differs from example 1 in that in step (II), niobium target 1 is activated with nitric acid.

Example 12

This example differs from example 1 in that in step (i), 46# white corundum was sprayed onto the bonding surface of the niobium target 1 at a spraying pressure of 0.3MPa to form a blasted surface having a roughness of 3 μm, and then brazing of the niobium target 1 to the copper backing plate 2 was performed.

Example 13

This example differs from example 1 in that in step (i), 46# white corundum was sprayed onto the bonding surface of the niobium target 1 at a spraying pressure of 0.6MPa to form a blasted surface having a roughness of 9 μm, and then brazing of the niobium target 1 to the copper backing plate 2 was performed.

The target assemblies brazed in the embodiments 1 to 13 were respectively removed, and the welding bonding rate and the single defect rate were measured by an ultrasonic C-scan imager, and the specific test results are shown in table 1.

TABLE 1

According to the brazing method of the niobium target 1 and the copper back plate 2, sand blasting and nickel plating are only carried out on the surface of the niobium target 1, so that the process flow is simplified, the working complexity is reduced, the roughness of the welding surface of the niobium target 1 and the copper back plate 2 is improved by carrying out sand blasting on the surface of the niobium target 1, and the bonding strength of a nickel layer and the welding surface is improved during subsequent nickel plating; the nickel plating treatment improves the welding performance of the niobium target 1 and the copper back plate 2, so that the niobium target 1 and the copper back plate 2 can be reliably combined, and the combination rate and the combination strength are improved; the copper wires 3 are arranged between the welding surfaces of the niobium target 1 and the copper back plate 2 and are uniformly distributed under the support of the copper wires 3, so that the welding flux between the target and the welding surface of the back plate is effectively reserved, the bonding strength of the niobium target 1 and the copper back plate 2 is improved, and the requirement of long-term stable use of the target assembly is met.

The applicant declares that the above description is only a specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and it should be understood by those skilled in the art that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are within the scope and disclosure of the present invention.