WO2019105422A1

WO2019105422A1 - Heating device and heating method

Info

Publication number: WO2019105422A1
Application number: PCT/CN2018/118260
Authority: WO
Inventors: 程静; 朱鸷
Original assignee: 上海微电子装备（集团）股份有限公司
Priority date: 2017-11-30
Filing date: 2018-11-29
Publication date: 2019-06-06
Also published as: CN109860073B; TW201926511A; TWI691008B; CN109860073A

Abstract

Disclosed are a heating device and a heating method thereof, wherein a sucking disc (32) is directly fixed to a heat insulation seat (35), a thin heater (34) hangs upside down from a lower surface of the sucking disc (32) via a soft fixing device (36), a force generated by thermal deformation of the heater (34) and the sucking disc (32) is delivered axially and downwardly, and the impact of the self-deformation of the heater (34) during heating on the height and flatness of the substrate (31) is reduced. A temperature homogenizing layer (33) is provided between the heater (34) and the sucking disc (32) to realize a uniform heat conduction between the heater (34) and the sucking disc (32), and a fixing layer (55) is provided on a lower surface of the heater (34) to prevent the heater (34) from warping due to the inability to transfer heat rapidly, which results in local heating of the heater. Meanwhile, the technical solution adopts a thin heater (34), the weight of the heating device is reduced, and the load requirement for a workbench is then reduced. Due to the decrease in the thickness of the heater (34), the heat capacity of the heater (34) is reduced, the heating and cooling cycle of the heating device is shortened, and the heating efficiency is improved.

Description

Heating device and heating method

Technical field

The present invention relates to the field of semiconductor technology, and in particular, to a bonding heating device and a heating method.

Background technique

Wafer bonding technology can bond wafers of different materials together. The use of wafer bonding technology to combine new structural materials has great freedom, and is widely used in microelectronic circuits, sensors, power device micromachining, optoelectronic devices, insulating silicon wafers and other fields.

The wafer bonding process generally heats a base material such as a silicon wafer or a glass substrate to a certain temperature in a vacuum environment, applies a certain external force, and performs bonding for a certain period of time. The main heating device of the existing wafer bonding apparatus is as shown in FIG. 1 : a heater 13 is formed by burying a heating wire in a metal plate of a superalloy by brazing, and the heater 13 is placed on the heat insulating seat 14 . The suction cup 12 is superimposed on the heater 13, or the heater 13 and the suction cup 12 are combined into one part, and the substrate 11 is adsorbed by the suction cup 12. The heat conduction in the heating process sequentially passes through the heater 13, the suction cup 12, and finally to the substrate 11, completing the heating of the substrate 11. . In the heating device, the heater 13 has a large weight, which has a great influence on the dynamic performance of the table carrying the heating device, is not suitable for the case where the weight is limited, and the thermal expansion during the heating process causes the heater 13 and the suction cup. The thickness of the whole 12 is thickened, so that the flatness (surface flatness) is deteriorated, and the height and flatness of the substrate 11 adsorbed on the chuck 12 are further affected. Since it is necessary to perform position detection on the substrate on the substrate 11 by the machine vision system in the wafer bonding apparatus, when the height of the substrate 11 changes or the flatness is poor, the machine vision system needs to increase the auto focus function, otherwise it is difficult to capture the substrate. Clear imaging of the chip on 11 affects position detection, but increasing this function increases system complexity and reduces yield, while the heater used for heating has a thicker thickness, a larger heat capacity, and a heating and cooling time. Longer, not suitable for occasions where frequent heating, cooling, and heating are required.

The use of a thin heater instead of the original thick heater can greatly reduce the weight of the heater. However, in the existing heating device, even a thin heater does not solve the increase in the thickness of the heater due to thermal expansion during heating. The flatness is getting worse. Due to the thin thickness of the thin heater, the thickness of the thin heater is less accurate than that of the original thick heater, and it has a certain arc shape, as shown in Fig. 2a (naturally placed suction cup 21, naturally placed thin heating In the existing heating device, after the thin heater and the suction cup are fixed, the suction cup is brought into an arc shape, as shown in Fig. 2b (the suction cup is fixed with the suction cup 23 after the suction cup is fixed, and the suction cup is fixed with the thin heater) The heater 24) causes the height dimension of the substrate relative to the insulating seat and the flatness of the substrate to be uncontrollable.

Summary of the invention

In order to solve the above problems, the present invention provides a heating device, which comprises: a heater, a suction cup and an insulation seat.

The suction cup is directly fixed on the heat insulating seat, the heat insulating seat supports an edge of a lower surface of the suction cup; the heater is connected to the lower surface of the suction cup and located at the heat insulating seat The inside.

Further, the heater is a thin heater.

Further, the weight ratio of the heater to the suction cup is less than 1.

Further, the heater is in contact with the lower surface of the suction cup.

Further, the heating device further includes a flexible fixing device, and the heater is fixed to a lower surface of the suction cup by the flexible fixing device.

Further, the flexible fixing device comprises a butterfly spring and a step bolt, and one end of the butterfly spring abuts against the step of the step bolt.

Further, the step height of the step bolt in the flexible fixing device is determined by the thickness and weight of the heater and the compression amount of the butterfly spring.

Further, the force required for the deformation of the butterfly spring in the flexible fixing device is smaller than the force required for the deformation of the suction cup, and the force required for the deformation of the butterfly spring is smaller than that of the heater. The force needed.

Further, the heating device further includes a temperature homogenizing layer between the heater and the chuck for achieving uniform heat transfer between the heater and the chuck.

Further, the heating device further includes a fixing layer fixed to the lower surface of the heater by the flexible fixing device.

Further, the load of the step bolt is greater than a sum of the heater, the temperature homogenizing layer, the fixed layer and the weight of the butterfly spring.

Further, the material of the suction cup is a titanium alloy.

Further, the total thickness of the suction cup is controlled within 8 mm during the heating process.

Accordingly, the present invention provides a heating method for heating a substrate using the heating device described above, comprising: fixing the substrate to an upper surface of the chuck; and heating the substrate.

Compared with the existing heating device, the invention directly fixes the suction cup on the heat insulating seat, and hangs the thin heater on the lower surface of the suction cup, and the force generated by the heat deformation of the heater and the suction cup is axially transmitted downward, thereby reducing the heater. The effect of self-deformation on the height and flatness of the substrate during heating.

Further, a temperature homogenizing layer is added between the heater and the suction cup to achieve uniform heat transfer between the heater and the suction cup, and a fixed layer is added on the lower surface of the heater to prevent the heater from being locally heated due to the rapid transfer of heat. Warpage occurred.

Further, the invention adopts a thin heater, which reduces the weight of the heating device, thereby reducing the load demand on the worktable. Due to the decrease of the thickness of the heater, the heat capacity of the heater is reduced, and the heating and cooling cycle of the heating device is shortened. Increased heating efficiency.

DRAWINGS

1 is a schematic structural view of a conventional heating device;

Figure 2a is a schematic view showing the structure of a naturally placed suction cup and a heater;

Figure 2b is a schematic structural view of the suction cup and the heater after being fixed;

3 is a schematic structural view of a heating device according to Embodiment 1 of the present invention;

4 is a schematic structural view of a flexible fixing device according to Embodiment 1 and Embodiment 2 of the present invention;

5 is a schematic structural view of a heating device according to Embodiment 2 of the present invention;

FIG. 6 is a schematic structural view of a heating device according to Embodiment 3 of the present invention.

Detailed ways

In order to make the content of the present invention clearer and easier to understand, the contents of the present invention will be further described below in conjunction with the accompanying drawings. Of course, the invention is not limited to the specific embodiment, and general replacements well known to those skilled in the art are also encompassed within the scope of the invention.

In the following, the present invention has been described in detail with reference to the accompanying drawings.

Embodiment 1

Please refer to FIG. 3 , which is a schematic structural diagram of a heating device according to Embodiment 1 of the present invention. As shown in FIG. 3, the heating device includes a suction cup 32, a temperature homogenizing layer 33, a heater 34, a heat insulating seat 35, and a flexible fixing device 36. The suction cup 32 realizes the load and adsorption of the substrate 31, the heater 34 realizes the heat output of the heating device, and the temperature between the suction cup 32 and the heater 34 can be selectively increased according to the type of the heater 34. The layer 33 is configured to achieve uniform heat transfer between the chuck 32 and the heater 34. The temperature homogenizing layer 33 and the heater 34 are hung upside down on the lower surface of the chuck 32 by the flexible fixing device 36. The suction cup 32 is supported by the heat insulating seat 35.

FIG. 4 is a schematic structural view of the flexible fixing device 36. As shown in FIG. 4, the flexible fixing device 36 includes a butterfly spring 41 and a step bolt 42. One end of the butterfly spring 41 abuts against the step of the step bolt 42, and the butterfly spring 41 is further One end abuts against the lower surface of the suction cup 32. Referring to FIGS. 3 and 4, the heater 34 and the temperature homogenizing layer 33 are hung upside down on the lower surface of the suction cup 32 by the flexible fixing device 36, that is, the step bolt 42 is fixed under the suction cup 32. The surface of the butterfly spring 41 carries the heater 34 and the temperature homogenizing layer 33 on the step of the step bolt 42. When the weight ratio of the heater 34 and the suction cup 32 is less than 1, when the heater 34 is hung upside down to the suction cup 32, the height and flatness of the suction cup 32 itself are not affected.

Selecting the step height of the step bolt 42 according to the thickness and weight of the heater 34 and the compression amount of the butterfly spring 41, so that the step bolt 42 is given the heating by the butterfly spring 41 after tightening The heater 34 and the temperature homogenizing layer 33 provide a supporting force to ensure the adhesion of the heater 34 to the suction cup 32, wherein the supporting force is greater than the heater 34, the temperature homogenizing layer 33, and The sum of the weights of the butterfly springs 41, preferably, the supporting force is one to two times the sum of the weights of the heater 34, the temperature homogenizing layer 33 and the butterfly spring 41 .

At the same time, the force required for the deformation of the butterfly spring 41 is smaller than the force required for the heater 34 to be deformed by heat. Similarly, the force required for the deformation of the butterfly spring 41 is smaller than the force required for the heat deformation of the suction cup 32. When the heater 34 performs heat output, the self-heat deformation causes the butterfly spring 41 to compress, reducing the influence of the heat deformation of the heater 34 on the suction cup 32.

In the heating device of the embodiment, the heater 32 may be a thick heater or a thin heater, preferably a thin heater, for example, a thin heater having a thickness of about 3 mm, compared to the existing thick heating. The weight of the thin heater itself is greatly reduced, thereby reducing the weight of the heating device, reducing the load requirement on the table, and reducing the heat capacity of the heater 32 due to the decrease in the thickness of the heater 32. The energy consumption of the heating of the heater 32 itself shortens the cycle of heating and cooling of the heating device, and improves the heating efficiency.

The material of the suction cup 32 in the embodiment is preferably TA12 (titanium alloy) material, and the high temperature performance of the TA12 material is better than that of the high temperature alloy or stainless steel material used in the prior art suction cup, and the suction cup 32 is reduced. The deformation amount at a high temperature causes the total thickness of the suction cup 32 to be controlled to be less than 8 mm throughout the heating process, and since the density of the TA12 material is about half that of the steel material, the suction cup 32 itself made of the TA12 material is reduced. The weight further reduces the load requirements on the workbench.

The present invention also provides a heating method for heating the substrate 31 by using the heating device described above, as follows:

First, the suction cup 32 is placed on the heat insulating seat 35, and the temperature homogenizing layer 33 and the heater 34 are hung upside down on the lower surface of the suction cup 32 by the flexible fixing device 36; preferably, First, the temperature homogenization layer 33 and the heater 34 are bored for the insertion of the butterfly spring 41, and secondly, the depth of the step bolt 42 into the butterfly spring 41 is adjusted to pass the heater 34. The temperature homogenizing layer 33 is attached to the suction cup 32; then, the substrate 31 is fixed to the upper surface of the suction cup 32 by vacuum suction; finally, the heater 34 performs heat output to the substrate 31 is heated.

Embodiment 2

Please refer to FIG. 5 , which is a schematic structural diagram of a heating device according to Embodiment 2 of the present invention. As shown in FIG. 5, the heating device includes a suction cup 52, a temperature homogenizing layer 53, a heater 54, a fixed layer 55, a flexible fixing device 56, and a heat insulating seat 57. The suction cup 52 realizes load and adsorption of the substrate 51, and the heater 54 realizes heat output of the heating device, and can be selectively added between the suction cup 52 and the heater 54 according to the kind of the heater 54. The temperature homogenization layer 53 realizes uniform heat transfer between the suction cup 52 and the heater 54. According to the type of the heater 54, a fixed layer 55 may be added to the lower surface of the heater 54 to realize the opposite. The fixing of the heater 54 prevents the heater 54 from being warped due to the inability of the heat to be transferred quickly, and the temperature homogenizing layer 53, the heater 54, and the fixed layer 55 pass the flexibility. The fixing device 56 is hung upside down on the lower surface of the suction cup 52, and the suction cup 52 is supported by the heat insulating seat 57.

In the heating device of the embodiment, the heater 54 may be a thin heater, preferably a brittle material heater having a thickness of about 1 mm, such as a ceramic heater, and the ceramic heater has a high heating speed if heated. If the heat is not transferred quickly, the ceramic heater may be locally heated and warped. To avoid such a phenomenon, in this embodiment, a fixed layer 55 is added on the lower surface of the heater 54 for realizing the ceramic heater. Timely delivery of heat. The fixing layer 55 and the temperature homogenizing layer 53 and the heater 54 are hung upside down on the lower surface of the suction cup 52 through the flexible fixing device 56.

As in the first embodiment, the weight ratio of the heater 54 and the suction cup 52 in the embodiment is less than 1. The material of the suction cup 52 is preferably TA12 material with good high temperature performance, and the flexible fixing device 56 includes a butterfly. The spring 41 and the step bolt 42 have a load greater than the sum of the heater 54, the temperature homogenizing layer 53, the fixed layer 55, and the butterfly spring 41.

The present invention also provides a heating method for heating the substrate 51 by using the heating device described above, as follows:

First, the suction cup 52 is placed on the heat insulation seat 57, and the temperature homogenization layer 53, the heater 54 and the fixed layer 55 are hung upside down to the suction cup 52 by the flexible fixing device 56. a lower surface; preferably, a hole is formed in the temperature equalizing layer 53 and the heater 54 for the insertion of the butterfly spring 41, and secondly, the depth of the step bolt 42 into the butterfly spring 41 is adjusted, so that The heater 54 is adhered to the suction cup 52 through the temperature homogenizing layer 53, and the fixing layer 55 is attached to the heater 54; then, the substrate 51 is fixed by vacuum suction. The upper surface of the suction cup 52 is described; finally, the heater 54 performs heat output to heat the substrate 51.

Embodiment 3

Please refer to FIG. 6 , which is a schematic structural diagram of a heating device according to Embodiment 3 of the present invention. As shown in FIG. 6, the heating device includes a suction cup 62, a heater 63, and a heat insulating seat 64. The suction cup 62 realizes load and adsorption of the substrate 61, the heater 63 realizes heat output of the heating device, and the heater 63 is fixed to the lower surface of the suction cup 62, and the suction cup 62 is supported by the heat insulating seat 64.

In the heating device of the present embodiment, the heater 63 may be a thin heater, preferably a flexible material heater having a thickness of about 0.2 mm, such as a polyimide heater. The polyimide heater is a flexible material, and the deformation generated during thermal expansion does not affect the flatness of the suction cup 62, so that it is not required to be fixed by a flexible fixing device.

With the above embodiment, in the present embodiment, the weight ratio of the heater 63 and the suction cup 62 is less than 1, and the material of the suction cup 62 is preferably TA12 material with good high temperature performance.

The present invention also provides a heating method for heating the substrate 61 by the heating device described above, as follows:

First, the suction cup 62 is placed on the heat insulating seat 64, and a heater 63 is fixed on the lower surface of the suction cup 62; then, the substrate 61 is fixed to the upper surface of the suction cup 62 by vacuum suction; Finally, the heater 63 performs heat output to heat the substrate 61.

In summary, the present invention directly fixes the suction cup on the heat insulating seat, and the thin heater is hung upside down on the lower surface of the suction cup by the flexible fixing device, and the force generated by the heat deformation of the heater and the suction cup is axially transmitted downward, thereby reducing the heating. The effect of the deformation of the device on the height and flatness of the substrate during heating. A temperature homogenizing layer is added between the heater and the suction cup to achieve uniform heat transfer between the heater and the suction cup, and a fixed layer is added on the lower surface of the heater to prevent the heater from being warped due to the inability of the heat to be transferred quickly. . At the same time, the invention adopts a thin heater, which reduces the weight of the heating device, thereby reducing the load demand on the worktable. Due to the reduction of the thickness of the heater, the heat capacity of the heater is reduced, and the heating and cooling cycle of the heating device is shortened, thereby improving Heating efficiency.

The above is only a preferred embodiment of the present invention and does not impose any limitation on the present invention. Any changes in the technical solutions and technical contents disclosed in the present invention may be made by those skilled in the art without departing from the technical scope of the present invention. The content is still within the scope of protection of the present invention.

Claims

A heating device comprising: a heater, a suction cup and an insulated seat,

The suction cup is directly fixed on the heat insulation seat, and the heat insulation seat supports an edge of a lower surface of the suction cup;

The heater is coupled to the lower surface of the suction cup and to the inside of the insulated seat.
The heating apparatus according to claim 1, wherein said heater is a thin heater.
The heating device according to claim 1, wherein the weight ratio of the heater to the suction cup is less than one.
The heating apparatus according to claim 1, wherein said heater is in contact with said lower surface of said suction cup.
The heating apparatus according to claim 1, further comprising a flexible fixing means, said heater being fixed to said lower surface of said suction cup by said flexible fixing means.
The heating apparatus according to claim 5, wherein said flexible fixing means comprises a butterfly spring and a step bolt, and one end of said disc spring abuts against a step of said step bolt.
The heating apparatus according to claim 6, wherein a step height of said step bolt is determined by a thickness and a weight of said heater and a compression amount of said butterfly spring.
A heating apparatus according to claim 6, wherein a force required for deformation of said butterfly spring is smaller than a force required for deformation of said suction cup, and a force required for said deformation of said butterfly spring is smaller than said heating The force required to deform the heat.
A heating apparatus according to claim 6, further comprising a temperature homogenizing layer between said heater and said suction cup for causing said heater and said suction cup Achieve uniform heat transfer between.
The heating apparatus according to claim 9, further comprising a fixing layer fixed to a lower surface of said heater by said flexible fixing means.
The heating apparatus according to claim 10, wherein said step bolt has a load greater than a sum of said heater, said temperature homogenizing layer, said fixed layer, and said butterfly spring.
The heating device according to any one of claims 1 to 11, characterized in that the material of the suction cup is a titanium alloy.
Heating device according to any one of claims 1-11, characterized in that the total thickness of the suction cup is controlled within 8 mm during the heating process.
A heating method for heating a substrate by using the heating device according to any one of claims 1 to 13, characterized in that it comprises:

Fixing the substrate on an upper surface of the suction cup;

The substrate is heated.