A method of planar target material binding

Abstract

The present application relates to the field of planar target material, and specifically discloses a planar target material binding method, which comprises the following steps: stacking a back plate, metal indium and target material layer by layer, inserting a metal wire between the back plate and the metal indium, connecting the first and last sections of the metal wire to an ultrasonic vibrator, initially correcting the orientation of the target material and the back plate, heating the back plate, driving the metal wire to vibrate by the ultrasonic vibrator, starting to bind the target material, fine-tuning the orientation of the target material and the back plate under high temperature after the binding is completed, and finally cooling to complete the processing. The binding method is simple to operate, and the target material is preliminarily positioned at room temperature, and only the orientation needs to be fine-tuned after subsequent heating, which can improve the bonding rate of the target material and reduce the operation risk caused by carrying and binding.

Description

Technical Field

[0001] This invention belongs to the field of planar target materials, and specifically relates to a method for bonding planar target materials. Background Technology

[0002] When using a target for magnetron sputtering coating, the target needs to be welded to the backing plate. The bonding quality of the target will affect the sputtering process, with adverse effects such as poor heat dissipation, poor conductivity, and easy target detachment.

[0003] The backing plate for planar sputtering targets is mostly made of copper, with indium used as the solder. High-quality sputtering targets require solder with low thermal resistance and good heat dissipation; good heat dissipation reduces sputtering detachment and target cracking. The solder needs sufficient strength and flexibility to balance residual stress after sputtering. Controlling the sputtering gap also reduces uneven deposition and cracking. Controlling the adhesion rate after sputtering ensures coating quality and overall strength.

[0004] The current challenge in planar target bonding lies in achieving a bonding rate exceeding 97% with increasingly larger target sizes, a target splicing gap of 0.2-0.5 mm, and positional deviation controlled within 0.5 mm. The current standard procedure involves first heating metallic indium to over 160°C until it melts, while simultaneously heating the backplate and target to similar temperatures. The metallic indium is then poured onto the bonding surfaces of the backplate and target, and an ultrasonic indium coating machine is used to repeatedly vibrate and wet the surfaces of the target and backplate, achieving surface metallization and enhancing adhesion. After metallization, the molten metallic indium on the surfaces of the backplate and target needs to be repeatedly cleaned to remove the oxide layer. Then, the bonding surfaces of the target and backplate are aligned, the target position and gap are adjusted, and the surface is cooled. The indium solidifies, bonding the target and backplate together to complete the bonding process.

[0005] The aforementioned bonding methods have several drawbacks. The target and backplate require separate back-side metallization, making the process complex. The ultrasonic indium coating machine repeatedly vibrates the target surface, which can easily cause internal cracks during metallization. Furthermore, handling and bonding the target and backplate at heights poses operational risks; repeated handling also increases the risk of cracking. Invention patent CN115261805A discloses a bonding method for planar targets. This method involves sandblasting the bonding surfaces of the target and backplate, then ultrasonically coating the treated surfaces with indium, and finally bonding the target and backplate together, followed by ultrasonic vibration of the target surface for back-side indium coating. This method still requires separate metallization of the bonding surfaces of the target and backplate, and this repeated operation increases the risk of target cracking. Given the current trend towards larger target sizes, it is necessary to invent a bonding method that reduces handling and high-temperature risks, improves bonding efficiency, and is easy to operate. Summary of the Invention

[0006] The purpose of this invention is to provide a method for bonding planar targets that reduces handling and high-temperature risks, improves bonding and adhesion rates, and is easy to operate.

[0007] To achieve the above objectives, the present invention provides a method for bonding planar targets, comprising the following steps:

[0008] (1) Protect the unbonded surface of the target material to be bonded and its surrounding area with tape, and protect the unbonded area of ​​the bonding surface of the backing plate with tape.

[0009] (2) Place the empty backplate to be bound on the heating table with the binding side of the backplate facing up and the non-binding side of the backplate in contact with the heating table.

[0010] (3) Several metal wires are arranged at intervals and parallel on the bonding surface of the back plate. The first and last ends of each metal wire are connected to the ultrasonic vibrator on the corresponding side. The ultrasonic vibrators on both sides of the back plate straighten the metal wires. Then, sheet-shaped metal indium is placed on the upper surface of each metal wire.

[0011] (4) The target is placed on the upper surface of the back plate. At this time, the bonding surface of the target is in contact with the metal indium, the splice seam between adjacent targets is inserted with the heat insulation sheet, and finally the edge of the target is fixed.

[0012] (5) The heating table is heated to 180℃-210℃ to melt metallic indium;

[0013] (6) The ultrasonic vibrators on both sides vibrate the metal wire, and the vibration of the metal wire eliminates the air inside the molten indium metal. The metal wire simultaneously rubs the bonding surface of the back plate and the target material, so that the back plate and the target material are bonded together.

[0014] (7) After 20-35 minutes, turn off the ultrasonic vibrator, recalibrate the target position, place a pressure block on the upper surface of the target to apply pressure, and clean the splice seam of the target. During the above process, the heating table gradually cools down to room temperature.

[0015] (8) Cut the metal wires according to the width of the target material, clean up the excess metal indium around the back plate and the target material, and complete the processing.

[0016] As an improvement to the above scheme, in step (3), when the ultrasonic vibrator clamps the metal wire, the metal wire is kept in a straight state, and the height of the ultrasonic vibrator connecting the metal wire is the same as the upper surface of the back plate, so that the metal wire can be repeatedly disassembled and reassembled.

[0017] As an improvement to the above scheme, in step (7), when applying pressure to the target and cleaning the target, the heating table is maintained at 150°C-170°C.

[0018] As an improvement to the above solution, the thickness of the sheet-like indium is 0.6mm-3.0mm, the metal wire is made of copper or aluminum wire with a diameter of 0.3mm-1.0mm, and the back plate is made of copper.

[0019] As an improvement to the above scheme, the interval between two adjacent metal wires is 10mm-50mm.

[0020] As an improvement to the above scheme, the vibration frequency of the ultrasonic vibrator is 15kHz-35kHz.

[0021] The present invention has the following beneficial effects: the bonding method is simple to operate, the target material is initially positioned at room temperature, and only the orientation needs to be finely adjusted after subsequent heating, which can improve the bonding rate of the target material and reduce the operational risks caused by handling and bonding.

[0022] 1. By utilizing the high thermal conductivity of copper backing plate and indium, the purpose of slow heating is achieved, reducing internal cracks caused by uneven heating of the target material.

[0023] 2. The indium metal is held between the back plate and the target material, which reduces the air contact during the indium melting process, reduces its oxidation, thereby improving the bonding rate. It also avoids the step of cleaning the surface oxides of the indium metal at high temperature, reducing workload and operational risks.

[0024] 3. When the ultrasonic vibration of the metal wire occurs, the irregular vibration of the metal wire simultaneously rubs the bonding surfaces of the back plate and the target material, achieving the purpose of wetting and enhancing the bonding strength. The vibrating metal wire can also eliminate the internal air of the molten indium metal, further improving the bonding rate.

[0025] 4. Compared with traditional processes, there is no need to metallize the back plate separately, which reduces the internal cracks in the target material caused by repeated vibration of the ultrasonic indium coating machine during target surface metallization. This reduces the internal stress generated after the indium material cools down, thus lowering the risk of target material cracking.

[0026] 5. There is no need to handle the target material at high temperatures, which reduces the risk of cracking of the target material and also reduces the workload of the operators. Attached Figure Description

[0027] Figure 1 This is a front view of the main structure in one embodiment;

[0028] Figure 2 This is a top view of the main structure in one embodiment;

[0029] Figure 3 This is a cross-sectional view of the main structure in one embodiment.

[0030] Explanation of reference numerals in the attached drawings: 11, back plate; 12, indium metal; 13, target material; 21, metal wire; 22, ultrasonic vibrator; 30, limiting block; 40, heating stage. Detailed Implementation

[0031] In the description of this invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "top surface," "bottom surface," "inner," "outer," "inner side," and "outer side," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0032] In the description of this invention, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. Where the terms "first," "second," and "third" are used for descriptive purposes and to distinguish technical features, they should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the sequential relationship of the indicated technical features.

[0033] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. The embodiments of this invention will now be described according to its overall structure.

[0034] Reference Figures 1 to 3 This invention discloses a method for bonding planar targets, comprising the following steps:

[0035] (1) Protect the non-bonding surface of the target material 13 to be bonded and its surrounding area with tape, and protect the non-bonding area of ​​the bonding surface of the back plate 11 with tape.

[0036] (2) Place the empty back plate 11 to be bound on the heating table 40 with the binding surface of the back plate 11 facing upward and the non-binding surface of the back plate 11 in contact with the heating table 40.

[0037] (3) Several metal wires 21 are arranged at intervals and parallel on the binding surface of the back plate 11. The first and last ends of each metal wire 21 are connected to the ultrasonic vibrator 22 on the corresponding side. The ultrasonic vibrator 22 located on both sides of the back plate 11 straightens the metal wires 21. Then, a sheet of metal indium 12 is placed on the upper surface of each metal wire 21. When the ultrasonic vibrator 22 clamps the metal wire 21, it keeps the metal wire 21 in a straight state. The height of the ultrasonic vibrator 22 connecting the metal wire 21 is the same as the height of the upper surface of the back plate 11, so that the metal wire 21 can be repeatedly disassembled and reassembled.

[0038] (4) The target material 13 is placed on the upper surface of the back plate 11. At this time, the bonding surface of the target material 13 is attached to the metal indium 12, the splice seam between adjacent targets 13 is inserted with heat insulation sheet, and finally the edge of the target material 13 is fixed. Limiting blocks 30 are provided on the edges of the target material 13 and the back plate 11 for subsequent clamping.

[0039] (5) The heating table is heated to 180℃-210℃ to melt 12g of metallic indium;

[0040] (6) The ultrasonic vibrators 22 on both sides vibrate the metal wire 21. The vibration of the metal wire 21 eliminates the air inside the molten indium 12. The metal wire 21 simultaneously rubs the bonding surfaces of the back plate 11 and the target material 13, so that the back plate 11 and the target material 13 are bonded together.

[0041] (7) After 20-35 minutes, turn off the ultrasonic vibrator 22, recalibrate the position of the target 13, place a pressure block on the upper surface of the target 13 to apply pressure, clean the splice seam of the target 13, and maintain the heating table 40 at 150℃-170℃ when applying pressure to the target 13 and cleaning the target 13; during the above process, the heating table 40 gradually cools down to room temperature;

[0042] (8) Cut the metal wire 21 according to the width of the target material 13, clean the excess metal indium 12 around the back plate 11 and the target material 13, and complete the processing.

[0043] As an improvement to the above solution, the thickness of the sheet-like indium 12 is 0.6mm-3.0mm, the metal wire 21 is made of copper or aluminum wire, and the diameter of the metal wire 21 is 0.3mm-1.0mm. The back plate 11 is made of copper. As an improvement to the above solution, the spacing between two adjacent metal wires 21 is 10mm-50mm. As an improvement to the above solution, the vibration frequency of the ultrasonic vibrator 22 is 15kHz-35kHz.

[0044] Example 1:

[0045] (1) The size of the target material 13 is 200mm×800mm. The non-bonding surfaces and the surrounding area of ​​the two target materials 13 to be bonded are protected with high temperature tape. The non-bonding area of ​​the bonding surface of the back plate 11 is protected with high temperature tape.

[0046] (2) The back plate 11 is made of copper. Place the empty back plate 11 on the heating table 40 with the bonding surface facing up. The bonding area is 200mm×1600mm.

[0047] (3) Copper wires are arranged at intervals on the bonding surface of the back plate 11, with a spacing of 10 mm and a diameter of 0.3 mm. The two ends of the copper wires are connected to ultrasonic oscillators and tightened.

[0048] (4) Place metal indium 12 on the upper surface of the copper wire, splice multiple pieces of metal indium 12, cut to the same size as the bonding area, and its thickness is 0.6mm;

[0049] (5) Two target materials 13 are bonded to the bonding surface of metal indium 12 thin blocks, placed on the back plate 11, the splicing seam is separated by a high temperature sheet, and the limiting blocks 30 at both ends are fixed by tooling fixtures;

[0050] (6) The heating table 40 is slowly heated to 190°C until the indium 12 melts;

[0051] (7) The ultrasonic oscillators on both sides vibrate the copper wire at a frequency of 20kHz. After 30 minutes, the oscillation stops. The position of the target 13 is adjusted, and a pressure block is placed on the target 13 to apply pressure. The heating table 40 is cooled down to 160℃. The gap of the target 13 is cleaned, and the heating table 40 is stopped heating and cooled down to room temperature.

[0052] (8) Cut the copper wire along the side of the target 13 and clean up the excess indium solder around it.

[0053] In Example 1, the binding position deviation of the target 13 was <0.2mm, the splicing gap was 0.3mm, and the bonding rate of the ultrasonic flaw detection target 13 was 97.7%.

[0054] Example 2:

[0055] (1) The size of the target material 13 is 180×550mm. The non-bonding surface and the surrounding area of ​​the target material 13 to be bound are protected with high temperature tape. The non-bonding area of ​​the binding surface of the back plate 11 is protected with high temperature tape.

[0056] (2) The back plate 11 is made of copper. Place the empty back plate 11 on the heating table 40 with the bonding surface facing up. The bonding area is 180mm×550mm.

[0057] (3) Aluminum wires are arranged at intervals on the back plate 11 with a spacing of 20mm and a diameter of 0.5mm. The two ends of the aluminum wires are connected to ultrasonic oscillators and tightened.

[0058] (4) Place indium 12 on the upper surface of the aluminum wire. The indium 12 is cut to the same size as the bonding area and has a thickness of 3mm.

[0059] (5) The target material 13 is placed on the back plate 11, the bonding surface of the target material 13 is bonded to the metal indium 12, the splice seam is separated by a high temperature sheet, and the end limit blocks 30 are fixed by tooling fixtures.

[0060] (6) The heating table 40 is slowly heated to 180°C until the indium 12 melts;

[0061] (7) The ultrasonic oscillators on both sides vibrate the aluminum wire at a frequency of 15kHz. After 20 minutes, the oscillation stops. The position of the target 13 is adjusted, and a pressure block is placed on the target 13 to apply pressure. The heating table 40 is cooled to 160℃. The gap of the target 13 is cleaned, and the heating table 40 is stopped heating and cooled to room temperature.

[0062] (8) Cut the aluminum wire along the side of the target 13 and clean up the excess indium solder around it.

[0063] In Example 2, the target 13 bonding position deviation was less than 0.2 mm, and the ultrasonic flaw detection target 13 bonding rate was 98.2%.

[0064] Example 3:

[0065] (1) The size of the target material 13 is 200mm×650mm. The non-bonding surfaces and the surrounding area of ​​the three target materials 13 to be bonded are protected with high temperature tape. The non-bonding areas of the bonding surface of the back plate 11 are protected with high temperature tape.

[0066] (2) The back plate 11 is made of copper. Place the empty back plate 11 on the heating table 40 with the bonding surface facing up. The bonding area is 200mm×1950mm.

[0067] (3) Copper wires are arranged at intervals on the back plate 11 with a spacing of 15mm and a diameter of 0.5mm. The two ends of the copper wires are connected to ultrasonic oscillators and tightened.

[0068] (4) Place metal indium 12 on the upper surface of the copper wire. The metal indium 12 is cut to the same size as the bonding area and has a thickness of 1.5 mm.

[0069] (5) Three target materials 13 are bonded to the bonding surface of metal indium 12 thin blocks, placed on the back plate 11, and the splicing seam is separated by a high temperature sheet. The end limit blocks 30 are fixed by tooling fixtures.

[0070] (6) The heating table 40 is slowly heated to 200°C until the indium 12 melts;

[0071] (7) The ultrasonic oscillators at both ends vibrate the copper wire at a frequency of 30kHz. After 35 minutes, stop the oscillation, adjust the position of the target 13, place a pressure block on the target 13 to apply pressure, cool down to 160℃, clean the gap of the target 13, and stop heating the heating table 40 to cool down to room temperature.

[0072] (8) Cut the copper wire along the side of the target material 13 and clean up the excess indium solder around it.

[0073] In Example 3, the target 13 bonding position deviation was <0.3mm, the splicing gap was <0.4mm, and the ultrasonic flaw detection target 13 bonding rate was 97.9%.

[0074] Comparative Example:

[0075] (1) The size of the target material 13 is 200mm×800mm. The non-bonding surfaces of the target material 13 to be bonded and the backing plate 11 are protected by high temperature tape.

[0076] (2) Place the indium 12 in the container on the heating table 40 and heat it to 180°C to a molten state. At the same time, heat the back plate 11 and the target material 13 to be bonded to 180°C with the bonding surface facing up.

[0077] (3) Pour molten indium 12 onto the bonding surface between the back plate 11 and the target 13, and use an ultrasonic indium coating machine to coat the bonding surface between the back plate 11 and the target 13 with indium, with an ultrasonic frequency of 20kHz.

[0078] (4) Clean the oxide layer of molten indium 12 on the surface of the back plate 11, and bond the target material 13 and the back plate 11 together;

[0079] (5) Fine-tune the position and gap of the target material 13, cool down, clean the solder and gap, and complete the bonding.

[0080] The obtained bonding target 13 has a bonding position deviation of <0.3mm, a splicing gap of 0.5mm, and an ultrasonic flaw detection target 13 bonding rate of 97.7%.

[0081] The target 13 obtained by bonding according to various embodiments of this application and the conventionally bonded target 13 are compared. The test results are shown in the table below.

[0082] Example 1 of this application Example 2 of this application Example 3 of this application Comparative Examples Adhesion rate (%) 97.7 98.2 97.9 97.7 Positional deviation (mm) ＜0.2 ＜0.2 ＜0.3 ＜0.3 Splicing gap (mm) 0.3 / ＜0.4 ＜0.4

[0083] As can be seen from the table above, the target material 13 manufactured by the present application method has a bonding rate, positional deviation, and splicing gap that are at or even better than those of the target material 13 obtained by conventional preparation methods, and all indicators meet the requirements for shipment.

[0084] The foregoing description of specific exemplary embodiments of the invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the invention to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the invention, as well as various different choices and variations. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. A method for bonding planar targets, characterized in that... Includes the following steps: (1) Protect the unbonded surface of the target material to be bonded and its surrounding area with tape, and protect the unbonded area of ​​the bonding surface of the backing plate with tape. (2) Place the empty backplate to be bound on the heating table with the binding side of the backplate facing up and the non-binding side of the backplate in contact with the heating table. (3) Several metal wires are arranged at intervals and parallel on the bonding surface of the back plate. The first and last ends of each metal wire are connected to the ultrasonic vibrator on the corresponding side. The ultrasonic vibrators on both sides of the back plate straighten the metal wires. Then, sheet-shaped metal indium is placed on the upper surface of each metal wire. (4) The target is placed on the upper surface of the back plate. At this time, the bonding surface of the target is in contact with the metal indium, the splice seam between adjacent targets is inserted with the heat insulation sheet, and finally the edge of the target is fixed. (5) The heating table is heated to 180℃-210℃ to melt metallic indium; (6) The ultrasonic vibrators on both sides vibrate the metal wire, and the vibration of the metal wire eliminates the air inside the molten indium metal. The metal wire simultaneously rubs the bonding surface of the back plate and the target material, so that the back plate and the target material are bonded together. (7) After 20-35 minutes, turn off the ultrasonic vibrator, recalibrate the target position, place a pressure block on the upper surface of the target to apply pressure, and clean the splice seam of the target. During the above process, the heating table gradually cools down to room temperature. (8) Cut the metal wires according to the width of the target material, clean up the excess metal indium around the back plate and the target material, and complete the processing.

2. The method for bonding planar targets according to claim 1, characterized in that: In step (3), when the ultrasonic vibrator clamps the metal wire, it keeps the metal wire in a straight position, and the height of the ultrasonic vibrator connecting the metal wire is the same as the upper surface of the back plate, so that the metal wire can be repeatedly disassembled and reassembled.

3. The method for bonding planar targets according to claim 2, characterized in that: In step (7), the heating table is maintained at 150°C-170°C when the target is pressured and cleaned.

4. The method for bonding planar targets according to claim 1, characterized in that: The sheet-like indium has a thickness of 0.6mm-3.0mm, the metal wire is made of copper or aluminum and has a diameter of 0.3mm-1.0mm, and the back plate is made of copper.

5. The method for bonding planar targets according to claim 4, characterized in that: The interval between two adjacent metal wires is 10mm-50mm.

6. The method for bonding planar targets according to claim 5, characterized in that: The vibration frequency of the ultrasonic vibrator is 15kHz-35kHz.

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