Positioning method for heating wire terminal of AlN ceramic heater

Abstract

The invention discloses a method for positioning a heating wire terminal of an AlN ceramic heater, and belongs to the technical field of semiconductors, and the method comprises the steps: S1, preparing a ceramic block with a groove: carrying out the groove processing of the ceramic block according to the distribution pattern of a heating wire, and forming the preparation of the ceramic block with the groove; s2, preparing an AlN ceramic heater green body: paving AlN ceramic powder in a mold to form a lower AlN ceramic powder layer, then putting the processed ceramic block with the groove into the mold, specifically, putting the ceramic block with the groove on the lower AlN ceramic powder layer, determining the position according to the actual position, correctly putting a heating wire terminal in the groove of the ceramic block, and then putting the heating wire terminal into the lower AlN ceramic powder layer to form the AlN ceramic heater green body; the AlN ceramic powder is laid again to form an upper AlN ceramic powder layer, and compression molding is carried out; and S3, hot pressed sintering: if the ceramic green bodies are formed in a dry press, the ceramic green bodies are subjected to degreasing and glue discharging and then are put into a hot pressing furnace to be sintered together, and if the ceramic green bodies are formed in the hot pressing furnace, sintering is directly carried out.

Description

Technical Field

[0001] The invention relates to the field of semiconductor technology, and in particular to a positioning method for a heating wire terminal of an AlN ceramic heater. Background Art

[0002] In the semiconductor manufacturing process, semiconductor wafers are subjected to film formation and etching. In these processes, AlN ceramic heaters are required to heat the wafers and keep the wafers within a certain temperature range. More importantly, the AlN-Heater must ensure the temperature uniformity of the processed wafer surface, because the uniformity of wafer temperature has a very important impact on the yield rate of semiconductor chips.

[0003] The heating wire of the AlN heating plate is connected to the nickel rod through the heating terminal, and the nickel rod is connected to the equipment controller. In the design, there are strict shape and position tolerances between the heating terminals. If the heating wire terminal is offset or misplaced during the preparation process, it cannot be connected to the nickel rod or there are too few connected parts, which will hinder the current transmission and cause the prepared AlN ceramic heater to be scrapped. Because the heating wire is combined with the AlN ceramic by co-firing and is completely ceramicized after high-temperature sintering, if the heating terminal is offset, even if only one terminal is offset, it cannot be repaired, resulting in serious consequences and causing the entire heating plate to be scrapped.

[0004] In the general AlN ceramic heater preparation process, ceramic powder and heating wire (molybdenum or tungsten material) are combined in the molding stage; for example, the conventional process is to first lay a layer of AlN powder to form a ceramic layer, then put in a heating wire as a heating layer, and then lay in AlN ceramic powder, and then form it as a whole, and then sinter it in a hot press furnace. However, this molding process has a big problem: when the ceramic powder and the heating wire are molded and pressed, the AlN powder will move in the axial and radial directions of the mold, and the powder will gradually change from a loose state to a dense state; in this process, the powder will move in the axial and radial directions at the same time, and when the powder moves radially, it will move with the heating wire terminal, causing the position between the heating wire terminals to shift, resulting in mismatch between the heating wire terminal and the connecting rod assembly. When the offset is out of tolerance, the product is at risk of being scrapped. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a method for positioning a heating wire terminal of an AlN ceramic heater to solve the problem raised in the background technology.

[0006] In order to solve the above technical problems, the technical solution of the present invention is:

[0007] A method for positioning a heating wire terminal of an AlN ceramic heater, the method comprising the following steps:

[0008] S1: Preparation of ceramic blocks with grooves:

[0009] The ceramic block is grooved according to the distribution pattern of the heating wire, wherein the groove matches the heating wire terminal, and the preparation of the grooved ceramic block is completed after the groove is processed on the ceramic block;

[0010] S2: Preparation of AlN ceramic heater green body:

[0011] AlN ceramic powder is spread in the mold to form a lower AlN ceramic powder layer, and then the grooved ceramic block processed as above is placed in the mold, and the grooved ceramic block is placed on the lower AlN ceramic powder layer, and the position is determined according to the actual position, and then the heating wire terminal is correctly placed in the groove of the ceramic block, and AlN ceramic powder is spread again to form an upper AlN ceramic powder layer, and finally the upper AlN ceramic powder layer, the grooved ceramic block, and the lower AlN ceramic powder layer are pressed to form an integral body;

[0012] S3: Hot Pressing Sintering:

[0013] If the ceramic green body is formed in a dry press, it must be degreased and debinded before being sintered together in a hot press furnace. If it is formed in a hot press furnace, it can be sintered directly.

[0014] Preferably, the pressing in step S2 is isostatic pressing, and the ceramic green sheet after pressing has a diameter of 45 mm and a thickness of 3 mm.

[0015] Preferably, the diameter of the heating wire terminal in step S1 is 30 mm.

[0016] Preferably, in step S2, AlN ceramic powder is spread in the mold to form a lower AlN ceramic powder layer, and then a positioning block with the same shape and size as the grooved ceramic block is placed on the lower AlN ceramic powder layer. Then, the lower AlN ceramic powder layer is pressed for the first time. After the first pressing, the positioning block is taken out, and the grooved ceramic block is placed in the groove formed after the positioning block is taken out. The heating wire terminal is placed on the grooved ceramic block, and then the upper AlN ceramic powder layer is spread and pressed.

[0017] Preferably, the ceramic block with grooves is a green ceramic block.

[0018] The above technical solution has the following beneficial effects:

[0019] Improve the positioning accuracy of the heating wire terminal in the AlN ceramic to avoid product scrapping due to the excessive tolerance of the heating terminal after sintering;

[0020] Improve the positioning accuracy of the heating terminal, improve the connectivity between the connecting rod and the heating terminal, and avoid poor contact at the interface between the product connecting rod and the heating terminal. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic cross-sectional structure diagram of an AlN ceramic heater of the present invention;

[0022] Figure 2 It is a schematic diagram of the structure of an AlN ceramic heater pressed in a mold according to the present invention. DETAILED DESCRIPTION

[0023] The specific embodiments of the present invention are further described below in conjunction with the accompanying drawings. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0024] In order to solve the problems of the prior art, the present application first separately prepares a ceramic block 7 with a groove, and requires that the diameter of the ceramic block 7 with a groove is larger than the distribution diameter of the heating terminal. The preparation process of the ceramic block 7 with a groove can be a dry-pressed ceramic block, an isostatically pressed ceramic block, a pre-sintered ceramic block or a fully sintered ceramic block; according to the distribution diagram of the heating terminal, the terminal and the distribution diagram groove of the heating wire 2 are processed by CNC; AlN ceramic powder is spread in the mold 4, and a CNC-processed ceramic block that conforms to the distribution pattern of the heating terminal is placed at the center of the mold 4, and the heating wire terminal 3 is placed in the groove with a groove, and then the heating wire 2 is placed, and then AlN ceramic powder is spread and pressed into one piece; the present invention limits the offset of the heating wire terminal 3 by pre-prepared ceramic blocks with grooves 7, thereby ensuring that the position tolerance of the heating wire terminal 3 is within the required range;

[0025] A method for positioning a heating wire terminal 3 of an AlN ceramic heater comprises the following steps:

[0026] S1: Preparation of the ceramic block 7 with grooves:

[0027] The ceramic block is grooved according to the distribution pattern of the heating wire 2, wherein the groove matches the heating wire terminal 3, and the preparation of the grooved ceramic block is completed after the groove is processed on the ceramic block;

[0028] A ceramic block 7 with a groove is prepared in advance, and the ceramic block 7 with a groove is a ceramic block green body, which is used to place the heating wire terminal 3, so that when the ALN ceramic heater green body is pressed, the position of the heating wire terminal 3 can be ensured, and the ceramic block 7 with a groove is also ALN ceramic, which is the same material as the ALN ceramic heater 1, so that they can be pressed together later and sintered together;

[0029] S2: Preparation of AlN ceramic heater green body:

[0030] refer to Figure 1 , Figure 2, AlN ceramic powder is spread in the mold 4 to form a lower AlN ceramic powder layer 5, and then the grooved ceramic block 7 processed as above is placed in the mold 4, and the grooved ceramic block 7 is specifically placed on the lower AlN ceramic powder layer 5, and the position is determined according to the actual position, and then the heating wire terminal 3 is correctly placed in the groove of the ceramic block, and AlN ceramic powder is spread again to form an upper AlN ceramic powder layer 6, and finally the upper AlN ceramic powder layer 6, the grooved ceramic block 7, and the lower AlN ceramic powder layer 5 are pressed to form an integral body; during pressing, the heating wire 2 is also pressed together, and finally sintered together;

[0031] When pressing the AlN ceramic powder, since the grooved ceramic block 7 is prepared in advance, its position will not change significantly due to pressure during the pressing process of the AlN ceramic powder, thus ensuring that the position tolerance of the heating wire terminal 3 is within the required range;

[0032] S3: Hot Pressing Sintering:

[0033] If the ceramic green body is formed in a dry press, the ceramic green body must be degreased and debinded before being placed in a hot press furnace for sintering. If it is formed in a hot press furnace, it is directly sintered, and the ALN ceramic heater 1 is formed after sintering.

[0034] In some embodiments, the pressing in step S2 is isostatic pressing, and the ceramic green sheet after pressing has a diameter of 45 mm and a thickness of 3 mm. The specific size can be selected according to requirements and needs;

[0035] The diameter of the heating wire terminal 3 in step S1 is 30 mm, and the specific size can be selected according to requirements and needs;

[0036] In some embodiments, in step S2, AlN ceramic powder is spread in the mold 4 to form a lower AlN ceramic powder layer 5, and then a positioning block of the same shape and size as the grooved ceramic block 7 is placed on the lower AlN ceramic powder layer 5, and then the lower AlN ceramic powder layer 5 is first pressed for the first time. After the first pressing, the positioning block is taken out, and the grooved ceramic block 7 is placed in the groove formed after the positioning block is taken out, and the heating wire terminal 3 is placed on the grooved ceramic block 7, and then the upper AlN ceramic powder layer 6 is spread and pressed. By setting the positioning block, the lower AlN ceramic powder layer 5 is pressed in advance, which is equivalent to reserving the position of the grooved ceramic block 7. Since the lower AlN ceramic powder layer 5 is pressed for the first time, in the subsequent pressing process, the displacement change is smaller, that is, after the grooved ceramic block 7 is placed in the position of the positioning block, it is combined with the upper AlN ceramic powder layer 6, and after pressing together, the position change of the heating wire terminal 3 is smaller and the precision is higher;

[0037] Compared with the prior art, the technical solution of this application has the following advantages:

[0038] Improve the positioning accuracy of the heating wire terminal 3 in the AlN ceramic to avoid product scrapping due to the excessive tolerance of the heating terminal after sintering;

[0039] Improve the positioning accuracy of the heating terminal, improve the connectivity between the connecting rod and the heating terminal, and avoid poor contact at the interface between the product connecting rod and the heating terminal.

[0040] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions and variations of these embodiments are made without departing from the principles and spirit of the present invention, and still fall within the scope of protection of the present invention.

Claims

1. A method for positioning a heating wire terminal of an AlN ceramic heater, characterized in that: The method comprises the following steps: S1: Preparation of ceramic blocks with grooves: The ceramic block is grooved according to the distribution pattern of the heating wire, wherein the groove matches the heating wire terminal, and the preparation of the grooved ceramic block is completed after the groove is processed on the ceramic block; S2: Preparation of AlN ceramic heater green body: AlN ceramic powder is spread in the mold to form a lower AlN ceramic powder layer, and then the grooved ceramic block processed as above is placed in the mold, and the grooved ceramic block is placed on the lower AlN ceramic powder layer, and the position is determined according to the actual position, and then the heating wire terminal is correctly placed in the groove of the ceramic block, and AlN ceramic powder is spread again to form an upper AlN ceramic powder layer, and finally the upper AlN ceramic powder layer, the grooved ceramic block, and the lower AlN ceramic powder layer are pressed to form an integral body; S3: Hot Pressing Sintering: If the ceramic green body is formed in a dry press, it must be degreased and debinded before being sintered together in a hot press furnace. If it is formed in a hot press furnace, it can be sintered directly.

2. The method for positioning the heating wire terminal of an AlN ceramic heater according to claim 1, characterized in that: The pressing in step S2 is isostatic pressing, and the ceramic green sheet after pressing has a diameter of 45 mm and a thickness of 3 mm.

3. The method for positioning the heating wire terminal of an AlN ceramic heater according to claim 1, characterized in that: The diameter of the heating wire terminal in step S1 is 30 mm.

4. The method for positioning a heating wire terminal of an AlN ceramic heater according to claim 1, characterized in that: In the step S2, AlN ceramic powder is spread in the mold to form a lower AlN ceramic powder layer, and then a positioning block with the same shape and size as the grooved ceramic block is placed on the lower AlN ceramic powder layer. Then, the lower AlN ceramic powder layer is pressed for the first time. After the first pressing, the positioning block is taken out, and the grooved ceramic block is placed in the groove formed after the positioning block is taken out. The heating wire terminal is placed on the grooved ceramic block, and then the upper AlN ceramic powder layer is spread and pressed.

5. The method for positioning the heating wire terminal of an AlN ceramic heater according to claim 1, characterized in that: The ceramic block with grooves is a ceramic block green body.

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