Electron beam welding parameter determination method based on tantalum target blank and niobium back plate

Abstract

The invention relates to an electron beam welding parameter determination method based on a tantalum target blank and a niobium back plate, which comprises the following steps: selecting proper electron beam welding parameters as a basic control group, then changing the electron beam welding parameters by adopting a control variable method so as to obtain different detection parameter values, and finally determining the electron beam welding parameters according to target detection parameter values. And the electron beam welding optimal parameters of the tantalum target blank and the niobium back plate are reversely confirmed, and a basis is provided for the electron beam welding process of the target blank and the niobium back plate.

Description

Technical Field

[0001] The invention relates to the technical field of target material welding, and in particular to a method for determining electron beam welding parameters based on a tantalum target blank and a niobium back plate. Background Art

[0002] With the rapid development of electronic technology, tantalum sputtering targets are increasingly used in integrated circuits. The sputtering process mainly uses physical vapor deposition, which uses high pressure to accelerate gaseous ion bombardment, so that the atoms of the target are sputtered out and deposited on silicon wafers or other substrates in the form of thin films, and then combined with processes such as photolithography to eventually form a complex wiring structure in semiconductor chips. Tantalum targets are mainly composed of tantalum target blanks and base back plates. Conventional circular targets are welded to the base over a large area, usually using diffusion welding, and the back plate material is usually aluminum alloy or copper alloy.

[0003] CN 103801820A discloses a hot isostatic pressing diffusion welding method for a tantalum target and an aluminum back plate, comprising: placing the tantalum target and the aluminum back plate into a vacuum jacket; evacuating the vacuum jacket; placing the vacuum jacket into a hot isostatic pressing furnace, first increasing the temperature and pressure, and then maintaining the temperature and pressure; decompressing and cooling the vacuum jacket; removing the vacuum jacket to take out the target material combination formed by welding the tantalum target and the aluminum back plate. However, diffusion welding generally uses hot pressing or hot isostatic pressing to achieve pressure and energy input, and the equipment and capital investment is large; at the same time, it is mainly suitable for welding large-area planar structures, and the welding surface machining requirements are high, and the welding surface structure should not be complicated. Therefore, there are limitations for welding special-shaped targets.

[0004] The application of electron beam welding in the welding of curved surfaces of special-shaped targets is relatively mature. CN 113319417A discloses a method for electron beam welding of targets for HCM machines, the method comprising: machining the raw material to form a pot-shaped target body, machining the end face at the opening of the target body into an inclined surface, and machining one end face of the flange into an inclined surface; assembling the target body and the inclined surface of the flange in contact and fixing them in a fixture; starting the electron beam welding equipment, vacuuming and performing electron beam welding, the direction of the electron beam is parallel to the assembly surface, and obtaining the target after welding. This method can effectively solve the problem that HCM Cu special-shaped targets are difficult to weld and form through reasonable welding structure design and appropriate fixtures.

[0005] In the electron beam welding process, the difference in melting points between the base material and tantalum should not be too large. Using tantalum material as the back plate is costly, while the melting point of niobium is close to that of tantalum. The two have similar physical and chemical properties, and the price of niobium is only 1 / 5 of that of tantalum. Therefore, niobium material can be selected as the back plate material and tantalum target blank for electron beam welding.

[0006] Currently, there is little research on the electron beam welding parameters of tantalum target blanks and niobium back plates. Therefore, in view of the shortcomings of the existing technology, it is necessary to provide a method for determining electron beam welding parameters that can achieve effective welding. Summary of the invention

[0007] The purpose of the present invention is to provide a method for determining electron beam welding parameters based on a tantalum target blank and a niobium back plate, adopt a control variable method to change the electron beam welding parameters, obtain different detection parameter values, and then reversely infer the optimal parameters of electron beam welding of the tantalum target blank and the niobium back plate according to the target detection parameter values.

[0008] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0009] The present invention provides a method for determining electron beam welding parameters based on a tantalum target blank and a niobium back plate, and the method for determining electron beam welding parameters comprises:

[0010] (1) selecting a control beam current value, a control focus depth, and a control line speed for electron beam welding of a tantalum target blank and a niobium backing plate;

[0011] (2) performing electron beam welding on the tantalum target blank and the niobium backing plate according to the control beam current value, control focus depth and control line speed selected in step (1), and detecting the weld depth and the molten pool width;

[0012] (3) changing any one or a combination of at least two of the control beam value, the control focus depth or the control line speed, and repeating step (2) to obtain the weld depth and molten pool width under different beam values, focus depths and line speeds;

[0013] (4) According to the target requirements of weld depth and molten pool width, the beam current value, focal depth and linear speed required for electron beam welding of tantalum target blank and niobium backing plate are determined.

[0014] The electron beam welding parameter determination method provided by the present invention is based on the selection of welding raw materials for tantalum target blanks and niobium back plates. First, suitable electron beam welding parameters are selected as a basic control group to obtain corresponding detection parameters of weld depth and molten pool width. Then, the electron beam welding parameters are changed by a control variable method to obtain different detection parameter values. Then, according to the target detection parameter values, the optimal electron beam welding parameters for the tantalum target blanks and the niobium back plates are reversely confirmed, which provides a basis for the electron beam welding process of the target blanks and the niobium back plates.

[0015] Preferably, the control beam current value in step (1) is 68-72 mA, for example, 68 mA, 69 mA, 70 mA, 71 mA or 72 mA, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0016] Preferably, the comparison focus depth in step (1) is 14-16 mm, for example, 14 mm, 14.5 mm, 15 mm, 15.5 mm or 16 mm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0017] Preferably, the control line speed in step (1) is 14-16 mm / s, for example, it can be 14 mm / s, 14.5 mm / s, 15 mm / s, 15.5 mm / s or 16 mm / s, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0018] In the present invention, firstly, appropriate beam current value, focal depth and linear speed are selected as a basic control group, which is conducive to obtaining the optimal electron beam welding parameter value after subsequent adjustment of the amplitude of each parameter.

[0019] Preferably, the weld depth in step (2) is 5-6 mm, for example, 5 mm, 5.3 mm, 5.5 mm, 5.8 mm or 6 mm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0020] Preferably, the molten pool width in step (2) is 1-2 mm, for example, 1 mm, 1.2 mm, 1.5 mm, 1.8 mm or 2 mm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0021] The weld depth and molten pool width are the corresponding values ​​obtained by testing the electron beam welding of the tantalum target blank and the niobium back plate by using the control beam value, the control focus depth or the control line speed. According to the value, a reference is provided for the subsequent adjustment of the control beam value, the control focus depth or the control line speed to achieve the target requirements of the weld depth and the molten pool width.

[0022] Preferably, the changing step in step (3) includes: using single variable control to adjust any one of the control beam value, control focus depth or control linear speed in sequence; and then adjusting the combination of at least two of the control beam value, control focus depth or control linear speed. Typical but non-limiting combinations include a combination of a control beam value and a control focus depth, a combination of a control focus depth and a control linear speed, or a combination of a control beam value, a control focus depth and a control linear speed.

[0023] In the present invention, a single variable is first controlled, and any one of the control beam value, the control focus depth or the control line speed is adjusted, and the other two parameters remain unchanged. Then, electron beam welding is performed, and the weld depth and the molten pool width are detected. Then, any one of the other two parameters is adjusted, and then electron beam welding is performed, and the weld depth and the molten pool width are detected. Then, the remaining parameter is adjusted, and electron beam welding is performed, and the weld depth and the molten pool width are detected. Then, according to the weld depth and the molten pool width values ​​obtained by the above adjustment, at least two of the control beam value, the control focus depth or the control line speed are selected for adjustment, and the remaining parameter remains unchanged. Then, electron beam welding is performed, and the weld depth and the molten pool width are detected. So far, the weld depth and the molten pool width corresponding to different beam values, focus depths and line speeds can be obtained.

[0024] Preferably, the adjustment range of the control beam current value in step (3) is -5 to 5 mA, for example, -5 mA, -2 mA, 2 mA, 3 mA or 5 mA, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0025] Preferably, the adjustment range of the control focus depth in step (3) is -5 to 10 mm, for example, it can be -5 mm, -2 mm, 5 mm, 8 mm or 10 mm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0026] Preferably, the adjustment range of the control line speed in step (3) is -10 to 5 mm / s, for example, it can be -10 mm / s, -5 mm / s, -2 mm / s, 2 mm / s or 5 mm / s, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0027] When the adjustment range of the control beam current value, the control focus depth and the control line speed is within a reasonable range, the optimal electron beam welding parameters can be obtained. If the adjustment range is too large or too small, it is not conducive to obtaining the optimal electron beam welding parameters.

[0028] Preferably, the range of the weld depth at different beam values, focal depths and linear speeds in step (3) is 4.1-9.5 mm, for example, it can be 4.1 mm, 4.3 mm, 4.9 mm, 5.3 mm, 5.8 mm, 6.2 mm, 6.7 mm, 7.3 mm, 7.4 mm, 9.3 mm or 9.5 mm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0029] Preferably, the range of the molten pool width at different beam current values, focal depths and linear speeds in step (3) is 0.8-5.3 mm, for example, it can be 0.8 mm, 1.1 mm, 1.2 mm, 1.4 mm, 1.5 mm, 2.1 mm, 3.5 mm, 3.8 mm or 5.3 mm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0030] Preferably, the target weld depth required in step (4) is greater than 7 mm, for example, it can be 7.5 mm, 8 mm, 9.3 mm, 10 mm or 11 mm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0031] Preferably, the target required molten pool width in step (4) is less than 4 mm, for example, it can be 3.9 mm, 3.8 mm, 3.5 mm, 3 mm or 2.5 mm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0032] Preferably, the beam current value required for the electron beam welding in step (4) is 69-71 mA, for example, it can be 69 mA, 69.5 mA, 70 mA, 70.5 mA or 71 mA, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0033] Preferably, the focal depth required for the electron beam welding in step (4) is 19.9-20.1 mm, for example, it can be 19.9 mm, 19.95 mm, 20 mm, 20.05 mm or 20.1 mm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0034] Preferably, the linear speed required for the electron beam welding in step (4) is 9.5-10.5 mm / s, for example, it can be 9.5 mm / s, 9.8 mm / s, 10 mm / s, 10.2 mm / s or 10.5 mm / s, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0035] The beam current value, focus depth and line speed required for the electron beam welding are optimally obtained according to the target required weld depth and molten pool width values, and excellent welding effect can be obtained in the electron beam welding process of tantalum target blank and niobium back plate.

[0036] As a preferred technical solution of the method for determining electron beam welding parameters of the present invention, the method for determining electron beam welding parameters comprises:

[0037] (1) The control beam current value for electron beam welding of the tantalum target blank and the niobium backing plate is 68-72 mA, the control focus depth is 14-16 mm, and the control line speed is 14-16 mm / s;

[0038] (2) performing electron beam welding on the tantalum target blank and the niobium back plate according to the control beam current value, control focus depth and control line speed selected in step (1), and detecting the weld depth and molten pool width; the weld depth is 5-6 mm, and the molten pool width is 1-2 mm;

[0039] (3) using single variable control, sequentially adjusting any one of the control beam value, control focal depth or control linear speed, and repeating step (2); then adjusting a combination of at least two of the control beam value, control focal depth or control linear speed, and continuing to repeat step (2) to obtain weld depth and molten pool width under different beam values, focal depths and linear speeds;

[0040] The adjustment range of the control beam current value is -5 to 5 mA, the adjustment range of the control focus depth is -5 to 10 mm, and the adjustment range of the control line speed is -10 to 5 mm / s; the range of the weld depth under different beam current values, focus depths and line speeds is 4.1-9.5 mm, and the range of the molten pool width is 0.8-5.3 mm;

[0041] (4) According to the target requirements of weld depth > 7 mm and molten pool width < 4 mm, the beam current value required for electron beam welding of tantalum target blank and niobium backing plate is determined to be 69-71 mA, the focus depth is 19.9-20.1 mm, and the line speed is 9.5-10.5 mm / s.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] (1) The electron beam welding parameter determination method provided by the present invention is based on the selection of welding raw materials for tantalum target blank and niobium back plate. First, appropriate electron beam welding parameters are selected as the basic control group to obtain the corresponding detection parameters of weld depth and molten pool width; then, the electron beam welding parameters are changed by the control variable method to obtain different detection parameter values, and then the optimal parameters of electron beam welding of tantalum target blank and niobium back plate are reversely confirmed according to the target detection parameter values, which provides a basis for the electron beam welding process of target blank and niobium back plate;

[0044] (2) By selecting appropriate control beam current value, control focus depth and control line speed adjustment range, the optimal electron beam welding parameters for electron beam welding of tantalum target blank and niobium backing plate can be obtained. The beam current value is 70mA, the focus depth is 20mm, and the line speed is 10mm / s, which can achieve excellent welding effect of tantalum target blank and niobium backing plate. DETAILED DESCRIPTION

[0045] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0046] Example 1

[0047] This embodiment provides a method for determining electron beam welding parameters based on a tantalum target blank and a niobium back plate, and the method for determining electron beam welding parameters includes:

[0048] (1) The control beam current value for electron beam welding of the tantalum target blank and the niobium backing plate is 70 mA, the control focus depth is 15 mm, and the control line speed is 15 mm / s;

[0049] (2) performing electron beam welding on the tantalum target blank and the niobium back plate according to the control beam current value, control focal depth and control linear speed selected in step (1), and detecting the weld depth and molten pool width; the weld depth is 5.3 mm, and the molten pool width is 1.2 mm;

[0050] (3) using single variable control, adjusting the control beam value, control focus depth and control line speed in sequence, and repeating step (2); then adjusting the control focus depth and control line speed, and continuing to repeat step (2) to obtain the weld depth and molten pool width under different beam values, focus depths and line speeds;

[0051] The adjustment ranges of the control beam current value are -5mA and 5mA respectively, the adjustment ranges of the control focus depth are -5mm, 5mm, and 10mm respectively, and the adjustment ranges of the control linear velocity are -10mm / s, -5mm / s, and 5mm / s respectively;

[0052] The weld depth and molten pool width values ​​under different beam current values, focal depths and linear speeds are shown in Table 1;

[0053] Table 1

[0054]

[0055] (4) According to the target requirements of weld depth > 7 mm and molten pool width < 4 mm, the beam current value required for electron beam welding of the tantalum target blank and the niobium back plate is determined to be 70 mA, the focus depth is 20 mm, and the line speed is 10 mm / s, that is, the electron beam welding parameters in adjustment item 9 are selected as the optimal electron beam welding parameters for the tantalum target blank and the niobium back plate.

[0056] Example 2

[0057] The present embodiment provides a method for determining electron beam welding parameters based on a tantalum target blank and a niobium back plate. The difference from Embodiment 1 is that the adjustment amplitude of the control beam current value in step (3) is replaced by -10mA, the adjustment amplitude of the control focus depth is replaced by -10mm, and the adjustment amplitude of the control line speed is replaced by -12mm / s, that is, the beam current value is adjusted to 60mA, the focus depth is adjusted to 5mm, and the line speed is adjusted to 3mm / s. The rest is the same as Embodiment 1.

[0058] The adjustment range of the control beam current value, control focus depth and control linear speed selected in this embodiment are all lower than the lower limit. The detected weld depth is 2 mm and the molten pool width is 3.7 mm, which cannot meet the target requirements and cannot achieve effective electron beam welding of the tantalum target blank and the niobium back plate.

[0059] Example 3

[0060] This embodiment provides a method for determining electron beam welding parameters based on a tantalum target blank and a niobium back plate. The difference from Embodiment 1 is that the adjustment amplitude of the control beam current value in step (3) is replaced by 10mA, the adjustment amplitude of the control focus depth is replaced by 15mm, and the adjustment amplitude of the control line speed is replaced by 10mm / s, that is, the beam current value is adjusted to 80mA, the focus depth is adjusted to 30mm, and the line speed is adjusted to 25mm / s. The rest is the same as Embodiment 1.

[0061] The adjustment ranges of the control beam current value, control focal depth and control linear speed selected in this embodiment are all higher than the upper limit. The detected weld depth is 5.7 mm and the molten pool width is 0.9 mm, which cannot meet the target requirements and cannot achieve effective electron beam welding of the tantalum target blank and the niobium back plate.

[0062] Comparative Example 1

[0063] This comparative example provides a method for determining electron beam welding parameters, and the method for determining electron beam welding parameters is performed using the method for determining electron beam welding parameters disclosed in CN104289808A.

[0064] In this comparative example, it is necessary to additionally select the range of the focusing current and consider the focusing current at different beam current values ​​or welding speeds. The required equipment is complex and difficult to operate. The electron beam welding parameter determination method provided in the present invention can meet the welding requirements for electron beam welding of tantalum target blanks and niobium back plates. The method is simple, easy to operate, and has lower cost.

[0065] In summary, the electron beam welding parameter determination method provided by the present invention is based on the selection of welding raw materials for tantalum target blank and niobium back plate. First, suitable electron beam welding parameters are selected as the basic control group to obtain corresponding detection parameters of weld depth and molten pool width; then, the electron beam welding parameters are changed by the control variable method to obtain different detection parameter values, and then, according to the target detection parameter values, the optimal parameters of electron beam welding of tantalum target blank and niobium back plate are reversely confirmed, which provides a basis for the electron beam welding process of target blank and niobium back plate;

[0066] By selecting appropriate control beam current value, control focus depth and control line speed adjustment range, the optimal electron beam welding parameters for electron beam welding of tantalum target blank and niobium back plate can be obtained. The beam current value is 70mA, the focus depth is 20mm, and the line speed is 10mm / s, which can achieve excellent welding effect of tantalum target blank and niobium back plate.

[0067] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention are within the protection scope and disclosure scope of the present invention.

Claims

1. A method for determining electron beam welding parameters based on a tantalum target blank and a niobium back plate, characterized in that: The electron beam welding parameter determination method comprises: (1) selecting a control beam current value, a control focus depth, and a control line speed for electron beam welding of a tantalum target blank and a niobium backing plate; (2) performing electron beam welding on the tantalum target blank and the niobium backing plate according to the control beam current value, control focus depth and control line speed selected in step (1), and detecting the weld depth and the molten pool width; (3) changing any one or a combination of at least two of the control beam value, the control focus depth or the control line speed, and repeating step (2) to obtain the weld depth and molten pool width under different beam values, focus depths and line speeds; (4) According to the target requirements of weld depth and molten pool width, the beam current value, focal depth and linear speed required for electron beam welding of tantalum target blank and niobium backing plate are determined.

2. The method for determining electron beam welding parameters according to claim 1, characterized in that: The control beam current value in step (1) is 68-72 mA; Preferably, the control focus depth in step (1) is 14-16 mm; Preferably, the control line speed in step (1) is 14-16 mm / s.

3. The method for determining electron beam welding parameters according to claim 1 or 2, characterized in that: The weld depth in step (2) is 5-6 mm; Preferably, the molten pool width in step (2) is 1-2 mm.

4. The method for determining electron beam welding parameters according to any one of claims 1 to 3, characterized in that: The changing step in step (3) includes: using single variable control to adjust any one of the control beam value, control focus depth or control linear velocity in sequence; and then adjusting a combination of at least two of the control beam value, control focus depth or control linear velocity.

5. The method for determining electron beam welding parameters according to any one of claims 1 to 4, characterized in that: The adjustment range of the control beam current value in step (3) is -5 to 5 mA; Preferably, the adjustment range of the control focus depth in step (3) is -5 to 10 mm; Preferably, the adjustment range of the control line speed in step (3) is -10 to 5 mm / s.

6. The method for determining electron beam welding parameters according to claim 5, characterized in that: The range of the weld depth under different beam current values, focal depths and linear speeds in step (3) is 4.1-9.5 mm.

7. The method for determining electron beam welding parameters according to claim 5, characterized in that: The range of the molten pool width under different beam current values, focal depths and linear speeds in step (3) is 0.8-5.3 mm.

8. The method for determining electron beam welding parameters according to claim 6 or 7, characterized in that: The target required weld depth in step (4) is >7 mm.

9. The method for determining electron beam welding parameters according to any one of claims 6 to 8, characterized in that: The target required molten pool width in step (4) is less than 4 mm.

10. The method for determining electron beam welding parameters according to any one of claims 5 to 9, characterized in that: The beam current value required for the electron beam welding in step (4) is 69-71 mA; Preferably, the focal depth required for the electron beam welding in step (4) is 19.9-20.1 mm; Preferably, the line speed required for the electron beam welding in step (4) is 9.5-10.5 mm / s.

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