WO2015085650A1

WO2015085650A1 - Method for diffusion welding w-ti alloy target material assembly

Info

Publication number: WO2015085650A1
Application number: PCT/CN2014/000787
Authority: WO
Inventors: 丁照崇; 张玉利; 刘书芹; 罗俊锋; 尚再艳; 何金江; 吕保国; 朱晓光
Original assignee: 有研亿金新材料有限公司
Priority date: 2013-12-12
Filing date: 2014-08-22
Publication date: 2015-06-18
Also published as: CN104708192A

Abstract

A method for diffusion welding a W-Ti alloy target material assembly for film coating, the method comprising: placing powdered raw material of W-Ti alloy target material and corresponding plate blank material to be welded and composited into a hot press mold and then into a hot press sintering furnace; synchronously conducting hot press sintering molding on the target blank and conducting diffusion welding on the target blank and plate blank to obtain a welded composite W-Ti alloy target material assembly; or utilizing the plate blank as a back plate or a transition layer to obtain the W-Ti alloy target material assembly or a composite three-layer structure of W-Ti alloy target material/ transition layer/ back plate. The method realizes synchronization between target blank hot press sintering molding and hot press diffusion welding of target blank and plate blank, with a welding tensile strength of greater than 50 MPa.

Description

Instruction manual

W-Ti alloy target component diffusion welding method

The invention belongs to the field of microelectronics, and particularly relates to a method for diffusion welding of a W-Ti alloy target component for coating.

Background technique

W-Ti alloy has low electron mobility, stable thermomechanical properties, good oxidation resistance and corrosion resistance, and is commonly used in microelectronics, such as semiconductor devices, semiconductor packages, Schottky diodes, Al, Cu, Ag wiring, etc. At present, the W-Ti alloy film manufacturing method mainly uses a magnetron sputtering W-Ti alloy target. Due to the high melting point of W-Ti alloy, it is usually formed by powder metallurgy process, such as pressureless sintering, hot pressing sintering, hot isostatic pressing, etc., and the target blank after sintering is machined into a single target, or with the back. The plates are welded into a composite target. For the composite target, on the one hand, the target and the back plate are required to have a very high welding ratio, so as to be well thermally conductive and electrically conductive during operation; on the other hand, the target and the back plate are required to have a certain welding strength to avoid working time. The target and the back plate are welded, peeled off, and the like. The backing material is usually Mo and alloy, Cu alloy, A1 alloy, austenitic stainless steel, Ti and alloy, etc. The welding methods include brazing and diffusion welding. Brazing is usually welded with low-melting In, Sn and alloy solders. The process is simple, but the bonding strength is low (within 10 MPa), and the solder melting point is low, which cannot meet the high-power sputter coating. Diffusion welding has the advantages of high welding rate and high welding strength, and is particularly suitable for high-power, high-efficiency sputtering coating targets. Diffusion welding is usually a welding method in which a solid target is formed in close contact with a backing plate, held at a certain temperature and pressure for a period of time, and the atoms between the contact surfaces are mutually diffused and mutually infiltrated to achieve metallurgical bonding. The package is vacuum-packed with the target and the back plate, and then subjected to hot isostatic pressure diffusion. However, the melting point difference between W-Ti alloy target and A1 alloy and Cu alloy backing material is large, and it is difficult to spread. It is necessary to add a transition layer between the two, and to form a step-by-step diffusion composite, such as adding austenitic stainless steel, Ni alloy, The transition layer such as Ti alloy is transitioned. However, the hot isostatic pressure diffusion welding process has very high requirements on the manufacturing technology of the jacket, and there is a risk that the jacket leaks and the welding cannot be welded, and the composite after the hot isostatic pressure diffusion usually has different degrees of bending deformation, and needs to be re-corrected. Ping, added process links.

In the Chinese patent "Tungsten-Titanium Alloy Target and Copper Alloy Back Sheet Diffusion Welding Method" (201110460946.2), a layer of aluminum diffusion auxiliary layer is arranged between the bulk W-Ti target and the back plate, and the composite is expanded by hot isostatic pressing. Vacuum envelope treatment is carried out, and effective compounding can be achieved under high pressure (such as ^ lOOMPa). Chinese patent "Method for manufacturing tungsten-titanium alloy target billet and target" (201110382822.7) for preparing W-Ti for hot press sintering The gold target blank does not involve diffusion compounding with the backing plate. Chinese patent "a diffusion welding method"

(200610155021.6), "Low-temperature diffusion welding method of tungsten alloy and niobium alloy" (201010596717.9) is a combination of block metal target and back plate heating and pressure diffusion, high pressure (such as lOOMPa) can achieve effective compounding, after compounding Easy to bend and deform, it is difficult to form near net size. The foreign patent "Method of bonding tungsten titanium sputter targets to titanium plates and target assemblies produced" (US5397050) uses a hot isostatic pressing process to achieve powdered W-Ti sintering and diffusion compounding with Ti backsheet. The design of the package is complicated and high. Under pressure (such as ^ lOOMPa), effective compounding can be achieved, and overall deformation is easy after compounding. In this patent, the hot-pressing process is used to realize the powder-like W-Ti and the backing plate or the transition layer diffusion composite. Under high temperature conditions, the W and Ti powders have strong activity, and the high-density W-Ti can be realized under relatively low pressure (such as 40 MPa). The target blank is sintered and composited with the effective diffusion of the backing plate. In addition, due to the mold, the net shape can be formed, the process is simple, and the composite after sintering and diffusion welding has no bending deformation, and the subsequent machining volume is small, and the material yield of the leather material is high. "Method for producing near net shape planar spinning targets and an intermediate therefor" (US5963778 ) The transition layer of the powder between the material and the backing plate is beneficial to diffusion compounding, and this patent The target material is sintered synchronously with the powder material and diffused and composited with the back sheet.

Summary of the invention

The purpose of the present invention is to provide a diffusion welding method for a W-Ti alloy target assembly.

A W-Ti alloy target component diffusion welding method, the steps are as follows:

(1) placing the W-Ti alloy target powder raw material and the corresponding composite slab material to be welded in a hot pressing mold;

(2) placing the hot-pressing mold of the W-Ti alloy powder raw material and the corresponding composite slab material to be welded in the step (1) in a hot-pressing sintering furnace, and performing the target billet hot-press sintering forming and the target blank at a time. The slab diffusion splicing, temperature 1000~1600 ° C, pressure 10~40 MPa, holding time 0.5~6 hr, to obtain a welded composite W-Ti alloy target assembly;

(3) directly using the slab as a backing plate, directly processing the welded composite W-Ti alloy target assembly obtained in step (2) into a W-Ti alloy target/backsheet finished product; or slab as a transition layer, Processing into W-Ti alloy target/transition layer assembly, and then hot pressing or hot isostatic pressure diffusion welding with A1 alloy or Cu alloy back plate to form W-Ti alloy target/transition layer/back plate composite Layer structure.

The W-Ti alloy target has a mass content of 5-20% and a balance of W.

The W-Ti alloy target has a cerium mass content of 10% and a balance of W. The average particle size of the W powder in the powder raw material is 2 to 10 μπι, and the average particle size of the Ti powder is 20 to 200 μm. Step (1) Before the mold is installed, sandblasting or machining may be performed on the slab welding surface in advance to improve the roughness of the welding surface.

Step (1) The single-layer structure of the target powder raw material and the slab material is loaded: the lower layer is a slab material, and the upper layer is a powder raw material.

Step (1) The target powder raw material and the slab double-layer structure are loaded: the lower layer is a powder raw material, the middle is a slab material, and the upper layer is a powder raw material.

The W-Ti alloy target has a diameter of (D50 to 500 mm and a thickness of 3 to 15 mm.

When the slab is used as a backing plate, the material is Mo and alloy, austenitic stainless steel or Ti and alloy; when the slab is used as a transition layer, the thickness is 0.5~5mm, and the material is austenitic stainless steel, Ni alloy or Ti and alloy.

The W-Ti alloy target diffusion welding method provided by the method of the present invention has the following advantages:

(1) Simultaneously realize sintering and diffusion welding: The method of the invention adds a composite slab material to be welded into the powder raw material, and simultaneously realizes sintering of the powder raw material into a dense target, and reacts the powder with the slab during the process. Diffusion welding, a diffusion splicing complex of the target and the slab is obtained at one time.

(2) High welding strength and high bonding rate: The diffusion welding method provided by the present invention initially contacts the slab in powder form, and the contact area is large, and the diffusion welding is easy, and the tensile strength of the welding can reach 50 Mpa or more. The rate can reach more than 99%.

(3) High target material yield: The diffusion welding method provided by the invention can realize near-net-size forming of target sintering and diffusion welding, and the composite after sintering and diffusion welding has no bending deformation, and the subsequent machining amount is small. The target material yield is high.

DRAWINGS

1 is a flow chart of a process for sintering and diffusion welding of a target according to the method of the present invention.

Fig. 2 is a schematic view showing the order of the single-layer structure of the target powder raw material and the slab.

Fig. 3 is a schematic view showing the order of the two-layer structure of the target powder raw material and the slab.

detailed description

The invention will be further described below by means of the drawings and specific embodiments.

The invention provides a diffusion welding method for a W-Ti target assembly. When a W-Ti alloy target is formed by hot press sintering, a corresponding slab to be welded is simultaneously added into the powder to realize hot pressing sintering of the target blank. The target blank and the slab diffusion welding are completed simultaneously. The method has the advantages of simple process, simultaneous realization of target sintering and diffusion welding, and initial contact with the slab to be welded in powder form, and the contact area between the two is large, and the diffusion welding is easy. The welding strength is high; on the other hand, the target material is sintered and the diffusion welding is nearly net-sized, and the sintering and diffusion-welding composites have no bending deformation, the subsequent machining amount is small, and the target material yield rate is high. In addition, the process is also suitable for diffusion bonding of high melting point powder metallurgy target components such as coatings and alloys, Mo and alloys, Cr and alloys in the field of microelectronics.

Example 1~4

According to the process flow chart shown in Figure 1, the steps are as follows:

1. Powder, slab preparation to be welded

According to the embodiment, the target powder material to be hot pressed and the corresponding slab material to be welded are prepared. The W-Ti alloy powder is: Ti mass content 5~20%, especially Ti mass content is 10%, and the balance is W. W powder average particle size 2~10μπι, Ti powder average particle size 20~200μηι. Molded target diameter (D50~500mm, thickness 3~15mm. Backsheet thickness depends on model specification, transition layer thickness

0.5~5mm. Sandblasting or machining can be carried out on the slab welding surface in advance to improve the roughness of the welding surface and increase the joint strength.

2. Mounting

The hot material for the target material to be hot pressed and the corresponding slab material to be welded are placed in a hot press mold, and the structural order is shown in Fig. 2, Fig. 3. The structure of Fig. 2 is a single-layer structure, which can realize single-layer target billet hot-press sintering, target billet and slab diffusion welding. The structure of Fig. 3 is a two-layer structure, which can realize double-layer target billet hot pressing sintering, target billet and board. Blank diffusion welding. The hot pressing mold is made of high-strength graphite with a compressive strength of 40 Mpa or more.

3. Hot pressing sintering, diffusion 悍

The hot press mold containing the powder raw material and the slab to be spliced is placed in a hot press sintering furnace, and the target billet is subjected to hot press sintering and the target billet and the slab diffusion welding. The process parameters mainly include temperature, hot pressing pressure and holding time.

4. Machining

After the hot press sintering and the diffusion welding are completed, a welded composite is obtained. The slab can be directly used as a backing plate to directly process the welded composite into a W-Ti alloy target/backsheet finished product; or the slab as a transition layer, processed into a W-Ti alloy target/transition layer component, and then with A1 The backing plate such as alloy or Cu alloy is subjected to hot pressing or hot isostatic pressure diffusion welding to form a three-layer structure of W-Ti alloy target/transition layer/back plate composite. The tensile strength of W-Ti alloy target and slab diffusion welding can reach more than 50Mpa. After C-axis-ultrasonic testing, the welding rate can reach more than 99%.

Examples 1 to 4 W-Ti alloy target sintering, welding process and performance results are shown in Table 1.

Table 1, sintering, welding process and performance results in Examples 1 to 4 No. Target composite (hot pressing) Secondary compounding (hot pressing + hot pressing or hot isostatic pressing) Welding welding

Welding rate transition welding strong

Back sheet process strength process rate backplane

% layer MPa

MPa %

Implementation W-5wt% 1550°C

Mo 70 99.3

Example 1 Ti x40MPax2hr

Implement W-10wt Ti 1450 Cu alloy or

120 99.8 Example 2 % Ti gold x40MPax2hr A1 alloy Implementation W- 15wt 1400

Ti 50 99.5

Example 3 % Ti x30MPax4hr

Implement W-20wt Ni to 1350 Cu alloy or

90 99.5 Example 4 % Ti gold x30MPax4hr AI alloy

Claims

claims

1. A diffusion welding method of W-Ti alloy target assembly, characterized in that the steps are as follows:

(1) Place the W-Ti alloy target powder raw material and the corresponding slab material to be welded and composited into the hot pressing mold;

(2) Place the hot-pressing mold containing the W-Ti alloy powder raw material and the corresponding slab material to be welded and composited in step (1) into a hot-pressing sintering furnace, and perform hot-pressing sintering and molding of the target blank at one time. Diffusion weld with the slab at a temperature of 1000~1600°C, a pressure of 10~amplitude Pa, and a holding time of 0.5~6hr to obtain a welded composite W-Ti alloy target assembly;

(3) The slab is directly used as a backing plate, and the welded composite W-Ti alloy target assembly obtained in step (2) is directly processed into a W-Ti alloy target/backing plate finished product; or the slab is used as a transition layer, It is processed into a W-Ti alloy target/transition layer assembly, and then hot pressed or hot isostatic pressure diffusion welding is performed with the A1 alloy or Cu alloy backing plate to form a composite W-Ti alloy target/transition layer/backing plate. layer structure.

2. The diffusion welding method of W-Ti target assembly according to claim 1, characterized in that the mass content of Ti in the W-Ti alloy target is 5~20%, and the balance is W.

3. The diffusion welding method of W-Ti target assembly according to claim 1, characterized in that the mass content of Ti in the W-Ti alloy target is 10%, and the balance is w.

4. The diffusion welding method of W-Ti target assembly according to claim 1, characterized in that the average particle size of W powder in the powder raw material is 2~10 μm, and the average particle size of Ti powder is 20~200 μm.

5. The diffusion welding method of W-Ti target assembly according to claim 1, characterized in that, before installing the mold in step (1), the welding surface of the slab can be sandblasted or machined in advance to improve the roughness of the welding surface. Spend.

6. The diffusion joining method of W-Ti target assembly according to claim 1, characterized in that, in step (1), the target powder raw material and the slab material are single-layer structure molded: the lower layer is the slab material, and the upper layer For powder raw materials.

7. The diffusion welding method of W-Ti target assembly according to claim 1, characterized in that in step (1), the target powder raw material and the slab are molded in a double-layer structure: the lower layer is the powder raw material, and the middle is the slab. Material, the upper layer is powder raw material.

8. The diffusion welding method of W-Ti target assembly according to claim 1, characterized in that the diameter of the W-Ti alloy target is 50~500mm and the thickness is 3~15mm.

9. The diffusion welding method of W-Ti target assembly according to claim 1, characterized in that when the slab is used as the backing plate, the material is Mo and alloys, austenitic stainless steel or Ti and alloys; the slab is used as the transition layer When the thickness is 0.5~5mm, the material is austenitic stainless steel, Ni alloy or Ti and alloy.