Upper bonding mechanism of wafer bonding device

Abstract

The invention relates to the technical field of wafer bonding, in particular to an upper bonding mechanism of a wafer bonding device, and mainly solves the technical problem that an upper heating plate of an existing wafer bonding device is low in cooling efficiency. The upper bonding mechanism of the wafer bonding device comprises a substrate, an upper heating plate, an upper cooling plate and a lifting driving part, the annular upper cooling plate is arranged above the upper heating plate, a water pipe is driven by the lifting driving part to ascend and descend so that the upper cooling plate can ascend and descend relative to the upper heating plate, and the upper cooling plate can make contact with the upper heating plate for cooling. In this way, the upper heating plate can be actively and directly cooled on the premise that the heating performance of the upper heating plate is not affected, and the cooling efficiency is high.

Description

Technical Field

[0001] The invention relates to the technical field of wafer bonding, and in particular to an upper 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] After bonding is completed, the bonding cavity needs to be cooled. However, since the upper heating plate of the existing bonding device needs to be raised and lowered, and in order to avoid the cooling structure affecting the heating performance of the upper heating plate, the upper heating plate is generally only forced to be cooled indirectly through a cooling mechanism arranged on the wall of the bonding cavity, and the cooling efficiency is low. Summary of the invention

[0004] In order to overcome the technical defect of low cooling efficiency of an upper heating plate of an existing wafer bonding device, the present invention provides an upper bonding mechanism of a wafer bonding device.

[0005] The upper bonding mechanism of the wafer bonding device provided by the present invention comprises: substrate; an upper heating plate suspended below the substrate via a lifting shaft that seals and penetrates the substrate; An upper cooling plate, which is suspended below the base plate by sealing a water pipe that penetrates the base plate, and the upper cooling plate is a ring plate and is slidably sleeved on the lifting shaft; A lifting drive component is installed above the base plate and connected to the water pipe.

[0006] Optionally, the upper heating plate includes a plate body, and a first graphite pad and a pasting plate are detachably fixed to the lower surface of the plate body in sequence.

[0007] Optionally, a second graphite pad is provided on the lower surface of the pasting plate.

[0008] Optionally, a third graphite pad is provided on the upper surface of the plate body.

[0009] Optionally, there are two water pipes, namely an inlet pipe and an outlet pipe.

[0010] Optionally, a pressure block is provided under the lifting shaft, and the pressure block is a T-shaped structure formed by a connecting shaft and a pressure plate. The connecting shaft is screwed to the middle part of the bottom surface of the lifting shaft, and a support ring is sleeved on the connecting shaft and the outer diameter of the support ring is larger than the diameter of the lifting shaft. The support ring is clamped between the lifting shaft and the pressure plate, and the upper heating plate is hoisted on the support ring by vertically arranged bolts. The upper heating plate and the pressure plate are in contact through a gasket to transmit pressure, and the lower surface of the pressure plate is set to be a spherical surface.

[0011] The technical solution provided by the present invention has the following advantages compared with the prior art: The upper bonding mechanism of the wafer bonding device provided by the present invention is equipped with an annular upper cooling plate above the upper heating plate, and the water pipe is driven to rise and fall by a lifting drive member to realize the lifting and lowering of the upper cooling plate relative to the upper heating plate. The upper cooling plate can contact with the upper heating plate for cooling, and can also be separated from the upper heating plate to avoid affecting the heating performance of the upper heating plate. In this way, the upper heating plate can be actively and directly cooled without affecting the heating performance of the upper heating plate, and the cooling efficiency is relatively high. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] 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.

[0013] 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.

[0014] Figure 1 A schematic diagram showing the structure of an upper bonding mechanism in an embodiment of the present invention; Figure 2 An exploded view of the assembly structure of the lifting shaft and the upper heating plate in an embodiment of the present invention is shown.

[0015] In the figure: 1. Base plate; 2. Upper heating plate; 21. Plate body; 22. First graphite pad; 23. Paste plate; 24. Second graphite pad; 25. Third graphite pad; 3. Lifting shaft; 31. Pressing block; 311. Connecting shaft; 312. Pressing plate; 32. Supporting ring; 33. Bolt; 34. Pad; 35. Ring block; 36. Pressing ring; 4. Upper cooling plate; 5. Water pipe; 51. Water inlet pipe; 52. Water outlet pipe; 6. Lifting drive component. DETAILED DESCRIPTION

[0016] 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.

[0017] 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.

[0018] 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.

[0019] Combine the following Figure 1 and Figure 2 The specific embodiments of the present invention are described in detail.

[0020] This embodiment provides an upper bonding mechanism of a wafer bonding device, including a substrate 1 , an upper heating plate 2 , an upper cooling plate 4 and a lifting drive member 6 .

[0021] The substrate 1 is mainly used to cooperate with the cavity shell below to form a closed bonding cavity.

[0022] The upper heating plate 2 is suspended below the substrate 1 through a lifting shaft 3 which is sealed and penetrates the substrate 1 .

[0023] Specifically, the upper heating plate 2 of the present embodiment includes a plate body 21, and the lower surface of the plate body 21 is detachably fixed with a first graphite pad 22 and a pasting plate 23 in sequence. Since the structure of the upper heating plate 2 is relatively complex and the cost is relatively high, if the upper heating plate 2 is directly used to contact the wafer for bonding, the upper heating plate 2 is very likely to be damaged by bumps, so the present embodiment adds a pasting plate 23 below the upper heating plate 2, and adds a first graphite pad 22 between the pasting plate 23 and the upper heating plate 2, so that the pasting plate 23 and the first graphite pad 22 can protect the upper heating plate 2 and ensure the service life of the upper heating plate 2, and the pasting plate 23 can be replaced when it is damaged. More specifically, the first graphite pad 22 and the pasting plate 23 can be fixed by snaps located on the side wall or other common methods.

[0024] More specifically, a second graphite pad 24 is disposed on the lower surface of the bonding plate 23. The second graphite pad 24 can ensure the uniformity of temperature when bonding the wafers by virtue of its high thermal conductivity, and can also prevent the wafers from being crushed by virtue of its flexibility.

[0025] More specifically, a third graphite pad 25 is disposed on the upper surface of the plate body 21. The third graphite pad 25 mainly facilitates heat conduction from the upper heating plate 2 to the upper cooling plate 4 by utilizing its good thermal conductivity, thereby achieving uniform and rapid heat dissipation.

[0026] Specifically, a pressure block 31 is provided below the lifting shaft 3. The pressure block 31 is a T-shaped structure formed by a connecting shaft 311 and a pressure plate 312. The connecting shaft 311 is screwed to the middle of the bottom surface of the lifting shaft 3. A support ring 32 is sleeved on the connecting shaft 311, and the outer diameter of the support ring 32 is larger than the diameter of the lifting shaft 3. The support ring 32 is clamped between the lifting shaft 3 and the pressure plate 312. The upper heating plate 2 is hoisted on the support ring 32 by vertically arranged bolts 33. The upper heating plate 2 and the pressure plate 312 are in contact through a pad 34 to transmit pressure, and the lower surface of the pressure plate 312 is set as a spherical surface. During operation, the wafer is placed on the lower bonding table. When the upper heating plate 2 contacts the wafer, if there is a slight tilt, it can be fine-tuned by the cooperation of the spherical surface and the pad 34 until the upper heating plate 2 is attached to the wafer in a parallel posture, further ensuring uniform pressure during wafer bonding.

[0027] More specifically, in this embodiment, an annular block 35 is provided between the support ring 32 and the upper heating plate 2, and a pressure ring 36 is provided above the support ring 32. The bolt 33 passes through the pressure ring 36, the support ring 32, the annular block 35 and the upper heating plate 2 from top to bottom in sequence. The annular block 35 makes the upper heating plate 2 indirectly contact with the support ring 32, which can improve the stability of the lower heating plate when bonding. The pressure ring 36 makes the pressure transmitted to the support ring 32 by the bolt 33 more uniform, avoiding local deformation.

[0028] It should be understood that when the upper heating plate 2 is fine-tuned with the cooperation of the spherical surface and the pad 34, the adjustment range is very small and can be ensured by the assembly gap between the structures.

[0029] The upper cooling plate 4 is suspended below the base plate 1 by sealing a water pipe 5 penetrating the base plate 1 . The upper cooling plate 4 is a ring plate and is slidably sleeved on the lifting shaft 3 .

[0030] Specifically, two water pipes 5 are provided, namely an inlet pipe 51 and an outlet pipe 52. Circulating cooling water enters the upper cooling plate 4 from the inlet pipe 51 and is then discharged from the outlet pipe 52. In this way, the heat of the upper heating plate 2 is taken away by the circulating cooling water, thereby achieving cooling.

[0031] The lifting drive member 6 is installed above the base plate 1 and connected to the water pipe 5 .

[0032] Specifically, the lifting drive member 6 is a cylinder, a cylinder body of the cylinder is fixed above the base plate 1 , and a piston rod of the cylinder is fixedly connected to the water pipe 5 .

[0033] 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. An upper bonding mechanism of a wafer bonding device, characterized in that: include: substrate(1); An upper heating plate (2) suspended below the substrate (1) via a lifting shaft (3) that seals and penetrates the substrate (1); An upper cooling plate (4) is suspended below the base plate (1) by means of a water pipe (5) that is sealed and penetrates the base plate (1); the upper cooling plate (4) is a ring plate and is slidably sleeved on the lifting shaft (3); A lifting drive member (6) is installed above the base plate (1) and connected to the water pipe (5).

2. The upper bonding mechanism of the wafer bonding device according to claim 1, characterized in that: The upper heating plate (2) comprises a plate body (21), and a first graphite pad (22) and a pasting plate (23) are detachably fixed in sequence on the lower surface of the plate body (21).

3. The upper bonding mechanism of the wafer bonding device according to claim 2, characterized in that: A second graphite pad (24) is provided on the lower surface of the pasting plate (23).

4. The upper bonding mechanism of the wafer bonding device according to claim 2, characterized in that: A third graphite pad (25) is provided on the upper surface of the plate body (21).

5. The upper bonding mechanism of the wafer bonding device according to claim 1, characterized in that: The water pipes (5) are provided with two, namely a water inlet pipe (51) and a water outlet pipe (52).

6. The upper bonding mechanism of the wafer bonding device according to any one of claims 1 to 5, characterized in that: A pressure block (31) is provided below the lifting shaft (3). The pressure block (31) is a T-shaped structure formed by a connecting shaft (311) and a pressure plate (312). The connecting shaft (311) is screwed to the middle of the bottom surface of the lifting shaft (3). A support ring (32) is sleeved on the connecting shaft (311) and the outer diameter of the support ring (32) is larger than the diameter of the lifting shaft (3). The support ring (32) is clamped between the lifting shaft (3) and the pressure plate (312). The upper heating plate (2) is hoisted on the support ring (32) by means of vertically arranged bolts (33). The upper heating plate (2) and the pressure plate (312) are in contact with each other via a pad (34) to transmit pressure, and the lower surface of the pressure plate (312) is set as a spherical surface.

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