Ultrathin aluminum heating plate and preparation method thereof

Abstract

The invention relates to an ultrathin aluminum heating plate and a preparation method thereof. The ultrathin aluminum heating plate sequentially comprises an aluminum sleeve, an upper aluminum plate body, a middle layer, an electric heating element and a lower aluminum plate body from top to bottom. The upper aluminum tray body and the lower aluminum tray body are respectively provided with a first groove, and the middle layer and the electric heating element are accommodated in a hollow part formed by overlapping; a through hole is formed in the position, corresponding to the upper aluminum plate body, of the middle layer, a second groove for containing the electric heating element is formed in the face, facing the lower aluminum plate body, of the middle layer, the ultra-thin aluminum heating plate can achieve thinning of the heating plate, and meanwhile temperature measurement and supporting performance are not affected.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing technology, and in particular to an ultrathin aluminum heating plate and its preparation method. Background Technology

[0002] Aluminum heating plates play a crucial role in semiconductor manufacturing. Their main functions include ensuring the quality of semiconductor wafer processing, providing uniform temperature distribution, and performing various processes at specific temperatures. Therefore, the temperature uniformity and support stability of aluminum heating plates are very important.

[0003] The standard thickness of aluminum heating plates on the market is approximately 40mm to ensure bending stiffness, thus meeting the basic requirements of traditional semiconductor manufacturing for support stability and temperature uniformity. There is an urgent need for an aluminum heating plate with a thickness of approximately 20mm. However, due to the reduced thickness and the properties of aluminum, it is more prone to deformation during use, thus affecting its temperature uniformity and support.

[0004] With the miniaturization and integration of semiconductor equipment, and the increasing demand for rapid thermal response in advanced processes, the market has placed clear demands on ultra-thin aluminum heating plates. On the one hand, the compression of internal space within the equipment cavity limits the installation height of the heating plate, necessitating ultra-thin products with a thickness reduced to around 20mm to fit into compact equipment designs. On the other hand, ultra-thin structures can reduce the heat capacity of the heating plate, increasing the heating rate, significantly shortening process waiting time, and improving production efficiency. However, halving the thickness to 20mm presents significant technical challenges for traditional structural designs: the inherent low stiffness of aluminum is amplified after thickness reduction, causing the heating plate to warp and dent under uneven thermal expansion and wafer pressure. This deformation can disrupt the fit between the heating wire and the plate, creating localized hot or cold spots, causing temperature uniformity to exceed acceptable limits, affecting processing quality and equipment operational safety.

[0005] Existing solutions have significant drawbacks: using aluminum alloys can negatively impact thermal conductivity; and employing external reinforcing ribs can disrupt temperature distribution. Therefore, developing a fabrication technology for aluminum heating plates that meets the 20mm ultra-thin thickness requirement while ensuring support stability and temperature uniformity has become a critical issue urgently needing to be addressed in the semiconductor equipment component field. Summary of the Invention

[0006] To solve the above-mentioned technical problems, the present invention uses an internally embedded titanium material as an intermediate layer to enhance the support of the heating plate, thereby solving the problem of poor support caused by the reduction in thickness.

[0007] To achieve this objective, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides an ultra-thin aluminum heating plate, which comprises, from top to bottom, an aluminum sleeve, an upper aluminum plate, an intermediate layer, an electric heating element, and a lower aluminum plate; the upper aluminum plate and the lower aluminum plate are respectively provided with a first groove, and the hollow portion formed by their stacking accommodates the intermediate layer and the electric heating element; the intermediate layer is provided with a through hole at a position corresponding to the upper aluminum plate, the aluminum sleeve is vertically disposed above the through hole, the heating wire passes through the aluminum sleeve and the through hole and contacts the lower aluminum plate, and the side of the intermediate layer facing the lower aluminum plate is provided with a second groove to accommodate the electric heating element.

[0009] This invention provides a support layer between the upper and lower plates of the aluminum heating plate, thereby preventing deformation of the aluminum plate during the heating process and improving the overall mechanical strength of the heating plate.

[0010] As a preferred embodiment of the present invention, the electric heating element includes a heating wire or a heating plate.

[0011] The specific material of the electric heating element described in this invention can be selected and optimized according to materials commonly used in the field, and no further limitation is made here.

[0012] As a preferred embodiment of the present invention, the intermediate layer is made of titanium.

[0013] The preferred material for the intermediate layer in this invention is titanium, which improves the support strength, reduces the thickness of the heating plate, and has strong chemical inertness during long-term hot and cold cycles, thus maintaining the stability of the support structure.

[0014] As a preferred technical solution of the present invention, the thickness of the upper aluminum plate and the lower aluminum plate is 8~12mm, for example, it can be 8mm, 9mm, 10mm, 11mm or 12mm.

[0015] As a preferred technical solution of the present invention, the depth of the first groove is 3~5mm, for example, it can be 3mm, 3.2mm, 3.8mm, 4mm, 4.2mm, 4.5mm or 5mm, etc.

[0016] As a preferred technical solution of the present invention, the thickness of the intermediate layer is 6~10mm, for example, it can be 6mm, 7mm, 8mm, 9mm or 10mm.

[0017] The present invention optimizes the thickness of the aluminum disc and the intermediate layer to balance heating effect and disc strength.

[0018] Preferably, the depth of the second groove is the same as the thickness of the electric heating element.

[0019] The depth of the second groove in this invention is the same as the thickness of the electric heating element, thereby ensuring full contact between the electric heating element and the plate, resulting in uniform heating effect.

[0020] Preferably, the thickness of the hollow portion formed by the first groove stacking is the same as the thickness of the intermediate layer.

[0021] Preferably, the first groove is stacked with the same thickness as the intermediate layer it accommodates, and the intermediate layer can fully contact and weld with the upper and lower discs.

[0022] Secondly, the present invention provides a method for preparing the ultrathin aluminum heating plate described in the first aspect, the method comprising the following steps:

[0023] (1) The pretreated aluminum upper plate and titanium intermediate layer are assembled and welded, and then machined to obtain a first component with a second groove and a through hole;

[0024] (2) The pre-treated aluminum lower plate, the first component, the sleeve and the heating wire are assembled and then welded to obtain the ultra-thin aluminum heating plate.

[0025] As a preferred technical solution of the present invention, the pretreatment in steps (1) and (2) includes polishing, pickling and drying the welding surface in sequence.

[0026] Preferably, the polishing is performed using 240-400 grit sandpaper, such as 240 grit, 320 grit or 400 grit, and 400-600 grit scouring pad, such as 400 grit, 500 grit or 600 grit.

[0027] Preferably, the acid washing reagent includes an aqueous solution of nitric acid and / or an aqueous solution of hydrofluoric acid.

[0028] Preferably, the concentration of the pickling reagent is 20-40 wt%, for example, it can be 20 wt%, 25 wt%, 30 wt%, 35 wt%, or 40 wt%.

[0029] Preferably, the pickling time is 1 to 3 minutes, for example, it can be 1 minute, 1.5 minutes, 2 minutes, 2.5 minutes or 3 minutes.

[0030] Preferably, the drying is carried out in a vacuum drying oven.

[0031] The drying time and temperature described in this invention can be selected and optimized according to the material and drying requirements, and are not further limited here.

[0032] Preferably, the machining includes turning.

[0033] As a preferred technical solution of the present invention, the welding in steps (1) and (2) includes sealing the assembled welded parts with a sleeve and performing hot isostatic diffusion welding after vacuum degassing.

[0034] Preferably, the temperature of the vacuum degassing is 150~250℃, for example, it can be 150℃, 180℃, 200℃, 220℃ or 250℃.

[0035] Preferably, the temperature of the hot isostatic diffusion welding is 450~550℃, for example, it can be 450℃, 480℃, 500℃, 520℃ or 550℃.

[0036] Preferably, the holding time for hot isostatic diffusion welding is 3 to 5 hours, for example, 3 hours, 3.5 hours, 4 hours, 4.5 hours or 5 hours.

[0037] Preferably, the material of the cladding used in step (1) is aluminum.

[0038] Preferably, the material of the sheath to be welded in step (2) includes stainless steel.

[0039] As a preferred technical solution of the present invention, the method includes the following steps:

[0040] (1) Polish the welding surfaces of the aluminum upper plate and the intermediate layer sequentially with 240~400 grit sandpaper and 400~600 grit scouring pad, pickle with nitric acid aqueous solution and / or hydrofluoric acid aqueous solution for 1~3 min, dry, seal with aluminum sleeve and vacuum degas, perform hot isostatic diffusion welding, and then remove the sleeve. The temperature of vacuum degassing is 150~250℃; the temperature of hot isostatic diffusion welding is 450~550℃; and the heat preservation time of hot isostatic diffusion welding is 3~5 h.

[0041] (2) Polish the welding surfaces of the aluminum lower plate, the first component and the sleeve in sequence with 240~400 grit sandpaper and 400~600 grit scouring pad, pickle with nitric acid aqueous solution and / or hydrofluoric acid aqueous solution for 1~3 min and then dry. After assembling the aluminum lower plate, the first component, the sleeve and the heating wire, seal them with a stainless steel sleeve and degas them under vacuum before performing hot isostatic pressure diffusion welding. The temperature of the vacuum degassing is 150~250℃; the temperature of the hot isostatic pressure diffusion welding is 450~550℃; the heat preservation time of the hot isostatic pressure diffusion welding is 3~5h. After welding, remove the sleeve to obtain the ultra-thin aluminum heating plate.

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

[0043] (1) By embedding a titanium intermediate layer in the middle of the ultra-thin aluminum heating plate, the present invention effectively avoids the warping and denting problems caused by the low rigidity of aluminum material in the ultra-thin structure, compared with the traditional thick aluminum heating plate, while reducing the thickness by half.

[0044] (2) The present invention makes the structure of the ultra-thin aluminum heating plate compact by hot isostatic pressing welding, balances the difference in thermal expansion coefficient between different materials, and ensures uniform heating temperature. The thinner aluminum material also improves the heating rate, which not only meets the requirements of semiconductor process for temperature uniformity, but also meets the needs of equipment miniaturization and rapid thermal response. Attached Figure Description

[0045] Figure 1 This is a structural diagram of the ultra-thin aluminum heating plate provided in Embodiment 1 of the present invention. Detailed Implementation

[0046] To facilitate understanding of the present invention, the following embodiments are provided. Those skilled in the art should understand that these embodiments are merely illustrative and should not be construed as limiting the scope of the invention.

[0047] Example 1

[0048] This embodiment provides an ultra-thin aluminum heating plate, such as Figure 1 As shown, the ultra-thin aluminum heating plate is provided from top to bottom as follows: an aluminum sleeve, an upper aluminum plate, a titanium intermediate layer, an electric heating element, and a lower aluminum plate. The upper and lower aluminum plates are each provided with a first groove, and the hollow portion formed by their stacking accommodates the titanium intermediate layer and the electric heating element. A through hole is opened in the intermediate layer at a position corresponding to the upper aluminum plate. The aluminum sleeve is vertically positioned above the through hole. The heating wire passes through the aluminum sleeve and the through hole and contacts the lower aluminum plate. A second groove is provided on the side of the titanium intermediate layer facing the lower aluminum plate to accommodate the electric heating element, which is a heating wire. The thickness of the upper and lower aluminum plates is 10 mm each. The depth of the first groove is 5 mm. The thickness of the titanium intermediate layer is 10 mm.

[0049] The ultra-thin aluminum heating plate is prepared using the following steps:

[0050] (1) Polish the welding surfaces of the aluminum upper plate and the titanium intermediate layer sequentially with 320-grit sandpaper and 500-grit scouring pad, pickle with 20wt% nitric acid aqueous solution for 3 min, dry in a vacuum drying oven at 100℃ for 30 min, seal with an aluminum sleeve and degas under vacuum, perform hot isostatic diffusion welding and then remove the sleeve. The temperature of the vacuum degassing is 200℃; the temperature of the hot isostatic diffusion welding is 500℃; and the heat preservation time of the hot isostatic diffusion welding is 4 h.

[0051] (2) The welding surfaces of the aluminum lower plate, the first component and the sleeve are polished sequentially with 320-grit sandpaper and 500-grit scouring pad, pickled with 20wt% nitric acid aqueous solution for 3 minutes and then dried in a vacuum drying oven at 100°C for 30 minutes. After the aluminum lower plate, the first component, the sleeve and the heating wire are assembled, they are sealed with a stainless steel sleeve and degassed under vacuum before hot isostatic pressure diffusion welding. The temperature of the vacuum degassed temperature is 200°C; the temperature of the hot isostatic pressure diffusion welding is 500°C; and the heat preservation time of the hot isostatic pressure diffusion welding is 4 hours. After the welding is completed, the sleeve is removed to obtain the ultra-thin aluminum heating plate.

[0052] Example 2

[0053] This embodiment provides an ultra-thin aluminum heating plate, which, from top to bottom, comprises an aluminum sleeve, an upper aluminum plate, a titanium intermediate layer, an electric heating element, and a lower aluminum plate. The upper and lower aluminum plates each have a first groove, and the hollow portion formed by their stacking accommodates the titanium intermediate layer and the electric heating element. The intermediate layer has a through hole corresponding to the position of the upper aluminum plate. The aluminum sleeve is vertically positioned above the through hole, and the heating wire passes through the aluminum sleeve and the through hole to contact the lower aluminum plate. The side of the titanium intermediate layer facing the lower aluminum plate has a second groove to accommodate the electric heating element, which is a heating wire. The thicknesses of the upper and lower aluminum plates are both 12 mm; the depth of the first groove is 3 mm; and the thickness of the titanium intermediate layer is 6 mm.

[0054] The ultra-thin aluminum heating plate is prepared using the following steps:

[0055] (1) Polish the welding surfaces of the aluminum upper plate and the titanium intermediate layer sequentially with 240-grit sandpaper and 400-grit scouring pad, pickle with 40wt% nitric acid aqueous solution for 1 min, dry in a vacuum drying oven at 100℃ for 30 min, seal with an aluminum sleeve and degas under vacuum, perform hot isostatic diffusion welding and then remove the sleeve. The temperature of the vacuum degassing is 150℃; the temperature of the hot isostatic diffusion welding is 550℃; and the heat preservation time of the hot isostatic diffusion welding is 3 h.

[0056] (2) Polish the welding surfaces of the aluminum lower plate, the first component and the sleeve in sequence with 240-grit sandpaper and 400-grit scouring pad, pickle with 40wt% nitric acid aqueous solution for 1 min and dry in a vacuum drying oven at 100℃ for 30 min. After assembling the aluminum lower plate, the first component, the sleeve and the heating wire, seal them with a stainless steel sleeve and degas them under vacuum before hot isostatic pressure diffusion welding. The temperature of the vacuum degassing is 150℃; the temperature of the hot isostatic pressure diffusion welding is 550℃; and the heat preservation time of the hot isostatic pressure diffusion welding is 3 h. After welding, remove the sleeve to obtain the ultra-thin aluminum heating plate.

[0057] Example 3

[0058] This embodiment provides an ultra-thin aluminum heating plate, which, from top to bottom, comprises an aluminum sleeve, an upper aluminum plate, a titanium intermediate layer, an electric heating element, and a lower aluminum plate. The upper and lower aluminum plates each have a first groove, and the hollow portion formed by their stacking accommodates the titanium intermediate layer and the electric heating element. The intermediate layer has a through hole corresponding to the position of the upper aluminum plate. The aluminum sleeve is vertically positioned above the through hole. The heating wire passes through the aluminum sleeve and the through hole and contacts the lower aluminum plate. The side of the titanium intermediate layer facing the lower aluminum plate has a second groove to accommodate the electric heating element, which is a heating wire. The thicknesses of the upper and lower aluminum plates are both 8 mm. The depth of the first groove is 4 mm. The thickness of the titanium intermediate layer is 8 mm.

[0059] The ultra-thin aluminum heating plate is prepared using the following steps:

[0060] (1) Polish the welding surfaces of the aluminum upper plate and the titanium intermediate layer sequentially with 400-grit sandpaper and 600-grit scouring pad, pickle with 30wt% nitric acid aqueous solution for 2 min, dry in a vacuum drying oven at 100℃ for 30 min, seal with an aluminum sleeve and degas under vacuum, perform hot isostatic diffusion welding and then remove the sleeve. The temperature of the vacuum degassing is 250℃; the temperature of the hot isostatic diffusion welding is 450℃; and the heat preservation time of the hot isostatic diffusion welding is 5 h.

[0061] (2) Polish the welding surfaces of the aluminum lower plate, the first component and the sleeve in sequence with 400-grit sandpaper and 600-grit scouring pad, pickle with 30wt% nitric acid aqueous solution for 2 min and dry in a vacuum drying oven at 100℃ for 30 min. After assembling the aluminum lower plate, the first component, the sleeve and the heating wire, seal them with a stainless steel sleeve and degas them under vacuum before hot isostatic pressure diffusion welding. The temperature of vacuum degassing is 250℃; the temperature of hot isostatic pressure diffusion welding is 450℃; the heat preservation time of hot isostatic pressure diffusion welding is 5 h. After welding, remove the sleeve to obtain the ultra-thin aluminum heating plate.

[0062] Comparative Example 1

[0063] This comparative example provides an ultra-thin aluminum heating plate, which is the same as in Example 1 except that it does not have a titanium intermediate layer and the depth of the first groove is used to accommodate the heating wire.

[0064] Comparative Example 2

[0065] This comparative example provides an aluminum heating plate, which is the same as Comparative Example 1 except that the thickness of the upper and lower aluminum plates is 20 mm respectively.

[0066] Comparative Example 3

[0067] This comparative example provides an aluminum heating plate, which is the same as Comparative Example 1 except that the thickness of the upper and lower aluminum plates is 15mm respectively.

[0068] Test methods

[0069] The flatness of the aluminum heating plates provided in Examples 1-3 and Comparative Examples 1-3 was measured before heating and after one month of use. The test results are shown in Table 1.

[0070] Test Results

[0071] Table 1

[0072]

[0073] The test results show that:

[0074] (1) As can be seen from Examples 1 to 3, the present invention can reduce the thickness of the aluminum heating plate to increase the heating rate while maintaining mechanical strength and avoiding deformation during multiple hot and cold cycles.

[0075] (3) As can be seen from Examples 1-3 and Comparative Examples 1-3, when the thickness of the aluminum heating plate is reduced to 20mm without setting an intermediate layer, the strength of the aluminum heating plate decreases significantly and it is easy to deform in the hot and cold cycle. When the thickness of the aluminum heating plate is 40mm, it cannot meet the needs of equipment miniaturization and rapid thermal response.

[0076] In summary, this invention achieves thinner plate while maintaining mechanical strength, increases heating rate, and reduces space occupation by setting an intermediate layer inside the aluminum heating plate. This makes it suitable for the miniaturization and rapid thermal response of semiconductor manufacturing equipment, does not affect temperature testing, and has a simple preparation method that can be mass-produced.

[0077] The applicant declares that the above description is only a specific embodiment 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 conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. An ultra-thin aluminum heating plate, characterized in that, The ultra-thin aluminum heating plate comprises, from top to bottom, an aluminum sleeve, an upper aluminum plate, an intermediate layer, an electric heating element, and a lower aluminum plate. The upper and lower aluminum plates are each provided with a first groove, and the hollow portion formed by their stacking accommodates the intermediate layer and the electric heating element. The intermediate layer has a through hole at a position corresponding to the upper aluminum plate, and the aluminum sleeve is vertically positioned above the through hole. The heating wire passes through the aluminum sleeve and the through hole and contacts the lower aluminum plate. The side of the intermediate layer facing the lower aluminum plate has a second groove to accommodate the electric heating element.

2. The ultra-thin aluminum heating plate according to claim 1, characterized in that, The electric heating element includes a heating wire or a heating plate.

3. The ultra-thin aluminum heating plate according to claim 1 or 2, characterized in that, The intermediate layer is made of titanium.

4. The ultra-thin aluminum heating plate according to any one of claims 1 to 3, characterized in that, The thickness of the upper aluminum plate and the lower aluminum plate is 8~12mm respectively.

5. The ultra-thin aluminum heating plate according to any one of claims 1 to 4, characterized in that, The depth of the first groove is 3~5mm.

6. The ultra-thin aluminum heating plate according to any one of claims 1 to 5, characterized in that, The thickness of the intermediate layer is 6~10mm; Preferably, the depth of the second groove is the same as the thickness of the electric heating element.

7. A method for preparing the ultrathin aluminum heating plate according to any one of claims 1 to 6, characterized in that, The method includes the following steps: (1) The pretreated aluminum upper plate and intermediate layer are assembled and welded, and then machined to obtain a first component with a second groove and a through hole; (2) The pre-treated aluminum lower plate, the first component, the sleeve and the heating wire are assembled and then welded to obtain the ultra-thin aluminum heating plate.

8. The method according to claim 7, characterized in that, The pretreatment described in steps (1) and (2) includes polishing, pickling, and drying the welding surfaces in sequence; Preferably, the polishing is performed sequentially using 240-400 grit sandpaper and 400-600 grit scouring pad; Preferably, the pickling reagent includes an aqueous solution of nitric acid and / or an aqueous solution of hydrofluoric acid; Preferably, the concentration of the pickling reagent is 20-40 wt%; Preferably, the pickling time is 1 to 3 minutes.

9. The method according to claim 7 or 8, characterized in that, The welding described in steps (1) and (2) includes sealing the assembled weldment with a sleeve and vacuum degassing before performing hot isostatic diffusion welding; Preferably, the temperature of the vacuum degassing is 150~250℃; Preferably, the temperature of the hot isostatic diffusion welding is 450~550℃; Preferably, the holding time for hot isostatic diffusion welding is 3-5 hours; Preferably, the material of the sheath to be welded in step (1) includes aluminum; Preferably, the material of the sheath to be welded in step (2) includes stainless steel.

10. The method according to any one of claims 7 to 9, characterized in that, The method includes the following steps: (1) Polish the welding surfaces of the aluminum upper plate and the intermediate layer sequentially with 240~400 grit sandpaper and 400~600 grit scouring pad, pickle with nitric acid aqueous solution and / or hydrofluoric acid aqueous solution for 1~3 min, dry, seal with aluminum sleeve and vacuum degas, perform hot isostatic diffusion welding, and then remove the sleeve. The temperature of vacuum degassing is 150~250℃; the temperature of hot isostatic diffusion welding is 450~550℃; and the heat preservation time of hot isostatic diffusion welding is 3~5 h. (2) Polish the welding surfaces of the aluminum lower plate, the first component and the sleeve in sequence with 240~400 grit sandpaper and 400~600 grit scouring pad, pickle with nitric acid aqueous solution and / or hydrofluoric acid aqueous solution for 1~3 min and then dry. After assembling the aluminum lower plate, the first component, the sleeve and the heating wire, seal them with a stainless steel sleeve and degas them under vacuum before performing hot isostatic pressure diffusion welding. The temperature of the vacuum degassing is 150~250℃; the temperature of the hot isostatic pressure diffusion welding is 450~550℃; the heat preservation time of the hot isostatic pressure diffusion welding is 3~5h. After welding, remove the sleeve to obtain the ultra-thin aluminum heating plate.

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