Lower bonding mechanism of wafer bonding device

Abstract

The invention relates to the technical field of wafer bonding, in particular to a lower bonding mechanism of a wafer bonding device, and mainly solves the technical problem that a wafer is easily damaged due to excessive pressure of an existing bonding table. According to the lower bonding mechanism of the wafer bonding device, an inverted-barrel-shaped lower bonding table is arranged on the outer side of a lower heating plate, a deformation part used for axial buffering is arranged on the side wall of the lower bonding table, a first graphite pad is arranged between a top end plate of the lower bonding table and the lower heating plate, and when the upper heating plate and the lower heating plate are heated to expand in the bonding process and the thickness is increased, the first graphite pad is arranged on the lower bonding table. According to the invention, the first graphite pad is matched with the deformation part to compensate the increase of the thickness, so that the wafer can be prevented from being damaged due to excessive pressure in the bonding process.

Description

Technical Field

[0001] The invention relates to the technical field of wafer bonding, and in particular to a lower bonding mechanism of a wafer bonding device. Background Art

[0002] Wafer bonding is the process of tightly bonding two mirror-polished homogeneous or heterogeneous wafers through chemical and physical effects to achieve vertical stacking and electrical interconnection in 3D integration and advanced packaging. Wafer bonding equipment generally integrates pre-processing devices such as baking, visual alignment, pre-bonding, and bonding devices. Among them, the bonding device is used to finally tightly bond the two wafers that are preliminarily connected together after pre-processing. The bonding device includes an upper heating plate and a lower heating plate, and the upper heating plate and the lower heating plate are pressed against each other to complete the bonding of the wafers.

[0003] The upper and lower heating plates are easily expanded by heat during the bonding process, resulting in an increase in thickness. However, the existing bonding device cannot make corresponding adjustments to the increase in thickness, which can easily cause excessive pressure on the wafer during the bonding process, thereby causing damage to the wafer. Summary of the invention

[0004] In order to overcome the technical defect of the existing bonding platform that the wafer is easily damaged due to excessive pressure, the present invention provides a lower bonding mechanism of a wafer bonding device.

[0005] The lower bonding mechanism of the wafer bonding device provided by the present invention comprises: A lower bonding platform, which is in an inverted barrel shape and has a fixed bottom opening end, and a side wall of the lower bonding platform is provided with a deformation portion for axial buffering; A lower heating plate is supported on the inner side of the lower bonding stage and contacts the top end plate of the lower bonding stage through a first graphite pad.

[0006] Optionally, the deformation portion is a rectangular corrugated tube segment.

[0007] Optionally, the lower heating plate is supported on the inner side of the lower bonding platform by a plurality of support columns, and the bottom ends of the support columns are connected to a fixed bottom plate.

[0008] Optionally, the support column is a height-adjustable adjustment rod.

[0009] Optionally, it also includes a lower cooling plate, which is a porous plate and is slidably sleeved on the left and right support columns, and the lower cooling plate is connected to a first lifting drive component for driving the lower cooling plate to rise and fall.

[0010] Optionally, the lower cooling plate includes a cooling base plate and a cooling cover plate, the surface of the cooling base plate is provided with a water storage tank, and the cooling cover plate is fixed to the surface of the cooling base plate to close the water storage tank to form a circulating water channel.

[0011] Optionally, a second graphite pad is provided on the lower surface of the lower heating plate, and a shape of the second graphite pad is adapted to the lower cooling plate.

[0012] Optionally, a top edge of the lower bonding platform has a plurality of notch grooves evenly distributed along the circumferential direction.

[0013] Optionally, it also includes a ejector pin assembly, which includes a lifting ring located outside the lower bonding platform and coaxially arranged, the lifting ring is connected to a second lifting drive member for driving the lifting and lowering thereof, the inner ring of the lifting ring is provided with a needle body, the needle body corresponds one-to-one to the notch groove and is placed in the corresponding notch groove.

[0014] The technical solution provided by the present invention has the following advantages compared with the prior art: The lower bonding mechanism for wafer bonding provided by the present invention is provided with an inverted barrel-shaped lower bonding platform on the outer side of the lower heating plate, the side wall of the lower bonding platform is provided with a deformation portion for axial buffering, and a first graphite pad is provided between the top end plate of the lower bonding platform and the lower heating plate. When the upper and lower heating plates expand due to heat during the bonding process, resulting in an increase in thickness, the first graphite pad can cooperate with the deformation portion to compensate for the increase in thickness, thereby preventing the wafer from being damaged due to excessive pressure during the bonding process. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 A schematic diagram showing the structure of the lower bonding mechanism in an embodiment of the present invention; Figure 2 An exploded view of the lower bonding mechanism in an embodiment of the present invention is shown.

[0018] In the figure: 1. Lower bonding table; 11. Deformation part; 12. Notch groove; 2. Lower heating plate; 3. First graphite pad; 4. Support column; 5. Bottom plate; 6. Lower cooling plate; 61. Cooling substrate; 62. Cooling cover plate; 7. First lifting drive member; 8. Second graphite pad; 9. Ejector pin assembly; 91. Lifting ring; 92. Second lifting drive member; 93. Pin body. DETAILED DESCRIPTION

[0019] In order to more clearly understand the above-mentioned objectives, features and advantages of the present invention, the scheme of the present invention will be further described below. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0020] In the description, it should be noted that the terms "first" and "second" are only used for descriptive purposes and should not be understood as indicating or implying relative importance. It should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be internal communication between two elements. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0021] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present invention, rather than all of the embodiments.

[0022] Combine the following Figure 1 and Figure 2 The specific embodiments of the present invention are described in detail.

[0023] This embodiment provides a lower bonding mechanism of a wafer bonding device, including a lower bonding stage 1 and a lower heating plate 2 .

[0024] The lower bonding platform 1 is in an inverted barrel shape with a fixed bottom opening end, and a deformation portion 11 for axial buffering is provided on the side wall of the lower bonding platform 1 .

[0025] It is easy to understand that the so-called fixed setting means that its position does not change during operation. In this embodiment, a cavity shell is provided, and the bottom opening end of the lower bonding stage 1 is fixedly connected to the cavity shell to achieve the fixed setting.

[0026] Specifically, the deformation portion 11 of this embodiment is a rectangular bellows segment. The force required for the deformation of the rectangular bellows segment should be less than the maximum pressure that the wafer can withstand. In this way, the rectangular bellows segment will be deformed before the pressure on the wafer reaches the maximum, thereby preventing the wafer from being damaged due to excessive pressure.

[0027] Specifically, the top edge of the lower bonding platform 1 is evenly distributed with a plurality of notches 12 along the circumferential direction. The notches 12 are mainly used to cooperate with the ejector pin assembly 9 mentioned later, and the relevant explanation is detailed in the corresponding part of the following text.

[0028] The lower heating plate 2 is supported on the inner side of the lower bonding platform 1 and is in contact with the top end plate of the lower bonding platform 1 through the first graphite pad 3 .

[0029] It should be noted that the first graphite pad 3 has two functions: first, the first graphite pad 3 itself has toughness, so that the distance between the lower heating plate 2 and the lower bonding platform 1 has a certain adjustment range, and then the deformation part 11 can compensate for the dimensional change of the upper heating plate or the lower heating plate 2 in the thickness direction when heated, thereby avoiding the upper heating plate from exerting excessive pressure on the wafer after it descends a set distance; second, the first graphite pad 3 has good thermal conductivity, and can evenly transfer the heat of the lower heating plate 2 to the entire surface of the first graphite pad 3, thereby making the heat distribution of the lower bonding platform 1 more uniform.

[0030] Specifically, the lower heating plate 2 of the present embodiment is supported on the inner side of the lower bonding stage 1 by a plurality of support columns 4 , and the bottom ends of the support columns 4 are connected to a fixed bottom plate 5 .

[0031] More specifically, the support column 4 is a height-adjustable adjustment rod. When installing, the lower heating plate 2 can be leveled by adjusting the height of each support column 4.

[0032] In addition, the lower bonding mechanism of this embodiment also includes a lower cooling plate 6, which is a porous plate and is slidably sleeved on the left and right support columns 4. The lower cooling plate 6 is connected to a first lifting drive member 7 for driving the lowering and lifting thereof.

[0033] It should be noted that, in order to avoid the cooling structure from affecting the heating performance of the heating plate, the existing bonding device only sets a cooling mechanism on the cavity wall of the bonding cavity, and the heating plate can only be forced to cool down indirectly, and the cooling efficiency is low. The present solution sets a lower cooling plate 6 under the lower heating plate 2. The lower cooling plate 6 can be raised and lowered to contact with the lower heating plate 2 for cooling, and can also be raised and lowered to separate from the lower heating plate 2 to avoid affecting the heating performance of the heating plate. In this way, the lower heating plate 2 can be actively and directly cooled without affecting the heating performance of the lower heating plate 2, and the cooling efficiency is high.

[0034] Specifically, the lower cooling plate 6 includes a cooling base plate 61 and a cooling cover plate 62. A water storage tank is provided on the surface of the cooling base plate 61. The cooling cover plate 62 is fixed on the surface of the cooling base plate 61 to close the water storage tank and form a circulating water channel. When in use, the circulating water channel is connected to the water inlet pipe and the water outlet pipe, and the circulating cooling water enters the circulating water channel from the water inlet pipe and then is discharged from the water outlet pipe. In this way, the heat of the lower heating plate 2 is taken away by the circulating cooling water, thereby achieving cooling.

[0035] Furthermore, a second graphite pad 8 is provided on the lower surface of the lower heating plate 2, and the shape of the second graphite pad 8 is adapted to the lower cooling plate 6. The main function of the second graphite pad 8 is to utilize its good thermal conductivity to facilitate the conduction of heat from the lower heating plate 2 to the lower cooling plate 6, thereby achieving uniform and rapid heat dissipation. Specifically, the second graphite pad 8 can be fixed by a buckle located on the side wall or other common methods.

[0036] In addition, the lower bonding mechanism of the present embodiment further includes a pin assembly 9, which includes a lifting ring 91 located outside the lower bonding stage 1 and arranged coaxially, the lifting ring 91 is connected to a second lifting drive member 92 for driving the lifting thereof, and the inner ring of the lifting ring 91 is provided with a needle body 93, the needle body 93 corresponds to the notch groove 12 one by one and is placed in the corresponding notch groove 12. During operation, the manipulator delivers the wafer into the bonding cavity, the second lifting drive member 92 drives the lifting ring 91 to rise, so that the needle body 93 props up the wafer, and then the manipulator withdraws from the bonding cavity, and then the second lifting drive member 92 drives the lifting ring 91 to descend so that the wafer falls on the upper surface of the lower bonding stage 1, completing the placement of the wafer.

[0037] The above is only a specific implementation of the present invention, which enables those skilled in the art to understand or implement the present invention. Although detailed descriptions are given with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments, and they should all be covered by the protection scope of the claims.

Claims

1. A lower bonding mechanism of a wafer bonding device, characterized in that: include: A lower bonding platform (1) which is in an inverted barrel shape and has a fixed bottom open end, and a side wall of the lower bonding platform (1) is provided with a deformation portion (11) for axial buffering; A lower heating plate (2) is supported on the inner side of the lower bonding platform (1) and is in contact with the top end plate of the lower bonding platform (1) through a first graphite pad (3).

2. The lower bonding mechanism of the wafer bonding device according to claim 1, characterized in that: The deformation portion (11) is a rectangular corrugated tube section.

3. The lower bonding mechanism of the wafer bonding device according to claim 1 or 2, characterized in that: The lower heating plate (2) is supported on the inner side of the lower bonding platform (1) via a plurality of support columns (4), and the bottom ends of the support columns (4) are connected to a fixed bottom plate (5).

4. The lower bonding mechanism of the wafer bonding device according to claim 3, characterized in that: The support column (4) is an adjustment rod with adjustable height.

5. The lower bonding mechanism of the wafer bonding device according to claim 3, characterized in that: It also includes a lower cooling plate (6), which is a porous plate and is slidably sleeved on the left and right support columns (4), and the lower cooling plate (6) is connected to a first lifting drive member (7) for driving the lower cooling plate (6) to rise and fall.

6. The lower bonding mechanism of the wafer bonding device according to claim 5, characterized in that: The lower cooling plate (6) comprises a cooling base plate (61) and a cooling cover plate (62); a water storage tank is provided on the surface of the cooling base plate (61); and the cooling cover plate (62) is fixed to the surface of the cooling base plate (61) so as to close the water storage tank and form a circulating water channel.

7. The lower bonding mechanism of the wafer bonding device according to claim 5, characterized in that: A second graphite pad (8) is provided on the lower surface of the lower heating plate (2), and the shape of the second graphite pad (8) is adapted to that of the lower cooling plate (6).

8. The lower bonding mechanism of the wafer bonding device according to claim 1, characterized in that: The top edge of the lower bonding platform (1) is provided with a plurality of notch grooves (12) evenly distributed along the circumferential direction.

9. The lower bonding mechanism of the wafer bonding device according to claim 8, characterized in that: The invention also comprises a pin assembly (9), wherein the pin assembly (9) comprises a lifting ring (91) located outside the lower bonding platform (1) and arranged coaxially, the lifting ring (91) being connected to a second lifting driving member (92) for driving the lifting ring, and the inner ring of the lifting ring (91) is provided with a pin body (93), the pin body (93) corresponding to the notch groove (12) one by one and being arranged in the corresponding notch groove (12).

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