Wafer bonding unit

Abstract

The utility model provides a kind of wafer bonding unit, including lower pressing plate, multiple interval distribution's elastic limiting mechanism and upper pressing plate, multiple interval distribution's elastic limiting mechanism is embedded in the periphery of wafer placement area on lower pressing plate, and elastic limiting mechanism includes buffer part and main part, and main part is embedded in the periphery of lower pressing plate, and buffer part is elastically connected with the top of main part, and the upper surface of buffer part in release state is higher than the upper surface of wafer placement area, and the wafer in wafer placement area is limited, when abnormality occurs to machine table and wafer is placed above buffer part, upper pressing plate is pressed down to wafer during pressing wafer, and buffer part is moved downward due to the downward pressure force from wafer until the upper surface of buffer part does not exceed the upper surface of wafer placement area, so as to avoid wafer breakage caused by stress concentration, and wafer that is not normally pressed can be recycled for secondary pressing, so as to improve product yield.

Description

Technical Field

[0001] This utility model belongs to the field of semiconductor device packaging and relates to a wafer bonding unit. Background Technology

[0002] In 2.5D / 3D advanced chip packaging technology, a silicon interposer is used as a transition carrier between the chip and the substrate to achieve higher-density interconnects and a more compact integrated structure. To meet the miniaturization requirements of package thickness and volume, the silicon interposer needs to undergo a thinning process to reduce its thickness to the hundreds of micrometers level. During this process, to prevent warping, cracking, or displacement of the thin wafer during processing, temporary bonding technology is typically used to temporarily bond the wafer to a rigid support substrate (such as transparent glass) to provide mechanical support. The implementation of the temporary bonding process relies on dedicated temporary bonding equipment, which includes multiple functional modules such as coating, edge washing, alignment, baking, and bonding units.

[0003] The bonding operation (BO) unit, as the core component of temporary bonding equipment, directly affects the success or failure of the process and the product yield due to its structural precision and operational stability. Bonding units (such as...) Figure 1 The wafer 4 (as shown) is typically composed of a lower pressing plate 1 and an upper pressing plate 2, and is provided with multiple stop pins 3 to limit the horizontal displacement of the wafer 4 (which is placed on the lower pressing plate 1 to be bonded at this time, including the wafer material to be bonded to the support substrate and the support substrate to be initially bonded to the wafer material) during the pressing process, so as to prevent the wafer 4 from slipping off.

[0004] In the current temporary bonding process of wafer 4, due to factors such as equipment malfunction, robotic arm positioning errors, or improper process window settings, wafer 4 may be misaligned during loading and unloading, causing a portion of wafer 4 to be placed on the top of the limiting post 3. Since the top of the limiting post 3 must be higher than the bearing plane to achieve its limiting function, when wafer 4 is placed on the limiting post 3 due to equipment malfunction, the limiting post 3 acts as a local support point for wafer 4. During the pressing process, the pressure applied by the upper pressing plate 2 will be concentrated at the contact point between wafer 4 and the limiting post 3, leading to stress concentration and potentially causing wafer 4 to break (e.g., wafer breakage event). Figure 2 As shown in the figure, this reduced the product yield.

[0005] Therefore, there is an urgent need to design a wafer bonding unit to improve the yield of temporary bonding processes. Utility Model Content

[0006] In view of the shortcomings of the prior art described above, the purpose of this utility model is to provide a wafer bonding unit to solve the problem of low product yield caused by abnormal wafer placement in the prior art.

[0007] To achieve the above and other related objectives, this utility model provides a wafer bonding unit, comprising:

[0008] A pressure plate is fixed on a wafer bonding machine, and the pressure plate includes at least a wafer placement area;

[0009] Multiple spaced elastic limiting mechanisms are embedded around the wafer placement area. Each elastic limiting mechanism includes a buffer part and a main body part. The main body part is embedded around the lower pressure plate. The buffer part is elastically connected to the top of the main body part. When the buffer part is in the released state, its upper surface is higher than the upper surface of the wafer placement area. When the buffer part is in the pressed state, its upper surface does not exceed the upper surface of the wafer placement area.

[0010] The upper laminating plate is located above the lower laminating plate and is adapted to the lower laminating plate. It is used to work together with the lower laminating plate to press the wafer located in the wafer placement area.

[0011] Preferably, the buffer portion includes a limiting structure and an elastic structure, wherein the limiting structure is connected to the top of the main body portion.

[0012] Preferably, the limiting structure includes a first limiting end and a second limiting end disposed opposite to each other, and a connecting post that fixes the first limiting end and the second limiting end together, wherein the elastic structure is sleeved around the connecting post.

[0013] Preferably, the main body is provided with a first opening adapted to the second limiting end, and the inner wall of the first opening is provided with a limiting part adapted to the connecting post, the limiting part being located above the second limiting end.

[0014] Preferably, the first end of the elastic structure abuts against the side of the first limiting end near the connecting post, the second end of the elastic structure abuts against the limiting part, and the second limiting end has a first preset distance from the bottom of the first opening.

[0015] Preferably, the limiting structure has a second opening adapted to the main body, the top of the main body is disposed in the second opening, the first end of the elastic structure abuts against the bottom of the second opening, the second end of the elastic structure abuts against the side of the main body facing the bottom of the second opening, the outer wall of the main body is provided with a guide groove extending along the central axis of the second opening, the inner wall of the second opening is provided with a guide protrusion adapted to the guide groove, and the guide protrusion is slidably disposed in the first guide groove.

[0016] Preferably, the plurality of the elastic limiting mechanisms are arranged in an array.

[0017] Preferably, the wafer bonding unit further includes a connection structure for connecting the upper bonding plate and the lower bonding plate, and a plurality of the connection structures are disposed around the wafer placement area and are distributed in an array.

[0018] Preferably, the wafer placement area is provided with mounting grooves around the perimeter that are adapted to the main body, and the main body is detachably connected to the mounting grooves.

[0019] Preferably, the wafer bonding unit further includes a driving mechanism connected to the upper bonding plate, which is used to drive the upper bonding plate closer to or further away from the lower bonding plate.

[0020] As described above, the wafer bonding unit provided by this utility model has the following beneficial effects: By setting multiple spaced elastic limiting mechanisms embedded around the wafer placement area on the lower pressing plate, the upper surface of the buffer part in the released elastic limiting mechanism is higher than the upper surface of the wafer placement area, which limits the wafer located in the wafer placement area. When the upper and lower pressing plates work together to press the wafer, the upper surface of the buffer part in the pressing state does not exceed the upper surface of the wafer placement area. When the machine malfunctions and the wafer is placed above the buffer part, during the wafer pressing process, the upper pressing plate presses down on the wafer, and the buffer part moves downward due to the downward pressure from the wafer. Since the upper surface of the buffer part in the pressing state does not exceed the upper surface of the wafer placement area, the force on the wafer from the buffer part is small when the bottom surface of the wafer is flush with the upper surface of the wafer placement area, thereby avoiding wafer breakage caused by stress concentration. Wafers that are not properly pressed can be recycled and then pressed again, improving product yield. Attached Figure Description

[0021] Figure 1 The diagram shows the structure of the bonding unit.

[0022] Figure 2 The diagram shows a structural schematic of a damaged wafer.

[0023] Figure 3The image shown is a top view of the wafer position anomaly according to this invention.

[0024] Figure 4 The diagram shown is a structural schematic of the wafer bonding unit of the unpressed wafer of this utility model.

[0025] Figure 5 The diagram shown is a structural schematic of the wafer bonding unit of the laminated wafer of this utility model.

[0026] Figure 6 The diagram shown is a partial structural schematic of the wafer bonding unit of this utility model.

[0027] Explanation of reference numerals in the attached drawings: 1-lower pressing plate; 2-upper pressing plate; 3-limiting post; 4-wafer; 5-wafer placement area; 6-elastic limiting mechanism; 61-buffer part; 6111-first limiting end; 6112-connecting post; 612-elastic structure; 62-main body; 621-first opening; 7-mounting groove. Detailed Implementation

[0028] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model.

[0029] It should be emphasized that the term "including / comprises" as used herein refers to the presence of a feature, whole, step, or component, but does not exclude the presence or addition of one or more other features, wholes, steps, or components.

[0030] Features described and / or illustrated for one embodiment may be used in the same or similar manner in one or more other embodiments, combined with features in other embodiments, or substituted for features in other embodiments.

[0031] In the detailed description of the embodiments of this utility model, for ease of explanation, the schematic diagrams illustrating the device structure may be partially enlarged without adhering to the general scale, and the schematic diagrams are merely examples and should not limit the scope of protection of this utility model. Furthermore, in actual manufacturing, the three-dimensional spatial dimensions of length, width, and depth should be included.

[0032] For ease of description, spatial relation terms such as “below,” “under,” “lower than,” “below,” “above,” and “upper” may be used herein to describe the relationship between one element or feature shown in the accompanying drawings and other elements or features. It will be understood that these spatial relation terms are intended to include directions other than those depicted in the drawings for devices in use or operation. Furthermore, when a layer is referred to as being “between” two layers, it may be the only layer between the two layers, or there may be one or more layers in between.

[0033] In the context of this application, the structure described above the first feature may include embodiments in which the first and second features are in direct contact, or embodiments in which additional features are formed between the first and second features, such that the first and second features may not be in direct contact.

[0034] It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Therefore, the illustrations only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0035] This application provides an embodiment of a wafer bonding unit, please refer to [link to relevant documentation]. Figure 3-5 As shown, the device includes a lower pressing plate 1, multiple spaced elastic limiting mechanisms 6, and an upper pressing plate 2. The lower pressing plate 1 is fixed to the wafer bonding machine platform and includes at least a wafer placement area 5. Multiple spaced elastic limiting mechanisms 6 are embedded around the wafer placement area 5. Each elastic limiting mechanism 6 includes a buffer part 61 and a main body part 62. The main body part 62 is embedded around the lower pressing plate. The top of the buffer part 61 is elastically connected to the top of the main body part 62. When the buffer part 61 is in the released state, its upper surface is higher than the upper surface of the wafer placement area 5. When the buffer part 61 is in the pressed state, its upper surface does not exceed the upper surface of the wafer placement area 5. The upper pressing plate 2 is located above the lower pressing plate 1 and is adapted to the lower pressing plate 1 for working together with the lower pressing plate 1 to press the wafer 4 located in the wafer placement area 5.

[0036] Specifically, a wafer bonding machine is a temporary bonding equipment specifically designed for temporary bonding processes. It includes multiple functional modules such as a coating unit, an edge washing unit, an alignment unit, a baking unit, a bonding unit, and auxiliary units.

[0037] Specifically, the shape, planar dimensions, and material of the lower pressing plate 1 can be selected according to actual needs, and the shape, planar dimensions, and material of the upper pressing plate 2 can also be selected according to actual needs. For example, both the upper pressing plate 2 and the lower pressing plate 1 are made of ceramic material. The number and specific structure of the elastic limiting mechanism 6 can be selected according to actual needs.

[0038] Specifically, the size and shape of the wafer placement area 5 can be selected according to actual needs. The wafer placement area 5 is adapted to the wafer 4. For example, the wafer placement area 5 is circular. It should be noted that the wafer 4 to be placed on the wafer placement area 5 includes the wafer material to be bonded to the support substrate and the support substrate to which the wafer material is initially bonded.

[0039] In this embodiment, the buffer portion 61 includes a limiting structure and an elastic structure 612, with the limiting structure connected to the top of the main body portion 62.

[0040] Specifically, the distance between the upper surface of the buffer portion 61 in the released state and the upper surface of the wafer placement area 5 can be selected according to actual needs. For example, the upper surface of the buffer portion 61 in the released state is about 2 mm higher than the upper surface of the wafer placement area 5. The material, size, and specific structure of the buffer portion 61 can be selected according to actual needs. The limiting structure is used to limit the wafer 4 located in the wafer placement area 5, preventing the wafer 4 from shifting relative to the wafer placement area 5. The elastic structure 612 extends and retracts vertically in a direction perpendicular to the wafer placement area 5. The fixed position of the main body 62 can be on the wafer bonding machine or in the peripheral area of ​​the wafer placement area 5 on the lower bonding plate 1. For example, Figure 6 As shown, the limiting structure is a bolt, the main body 62 is a sleeve-type structure, and the elastic structure 612 is a spring. The bolt is embedded in the sleeve-type structure, and the spring is set in the gap space between the bolt and the sleeve. When the upper pressing plate 2 is spaced a certain distance from the wafer 4 (in a normal position) located in the wafer placement area 5 in a direction perpendicular to the wafer placement area 5, the buffer part 61 is in a released state, which limits the wafer 4. When the machine malfunctions and the wafer 4 is placed above the buffer part 61 (the wafer 4 is in an abnormal position), when the upper pressing plate 2 moves downward and works together with the lower pressing plate 1 to press the wafer 4, the upper pressing plate 2 presses down on the wafer 4, and the buffer part 61 is subjected to the downward pressure force from the wafer 4 and moves downward until the upper surface of the buffer part 61 in the pressed state does not exceed the upper surface of the wafer placement area 5. When the bottom surface of the wafer 4 is flush with the upper surface of the wafer placement area 5, the force on the wafer 4 from the buffer part 61 is small, which can avoid stress concentration and thus avoid wafer 4 breakage caused by stress concentration.

[0041] In this embodiment of the application, the limiting structure includes a first limiting end 6111 and a second limiting end disposed opposite to each other, and a connecting post 6112 fixedly connecting the first limiting end 6111 and the second limiting end, with the elastic structure 612 sleeved around the connecting post 6112.

[0042] Specifically, the specific structure, dimensions, and materials of each part of the limiting structure (first limiting end 6111, second limiting end, and connecting post 6112) can be set according to actual needs. It should be noted that the dimensions of the first limiting end 6111 and the second limiting end are both larger than the dimensions of the connecting post 6112. For example, the first limiting end 6111, the second limiting end, and the connecting post 6112 are all cylinders, wherein the diameters of the first limiting end 6111 and the second limiting end are both larger than the diameter of the connecting post 6112. For example, a spring is used as an elastic structure 612 sleeved around the connecting post 6112.

[0043] In this embodiment of the application, the main body 62 is provided with a first opening 621 adapted to the second limiting end, and a limiting part adapted to the connecting post 6112 is provided on the inner wall of the first opening 621. The limiting part is located above the second limiting end.

[0044] Specifically, the size, specific structure and material of the main body 62 can be set according to actual needs. The central axis of the first opening 621 is perpendicular to the plane where the wafer placement area 5 is located, and the first limiting end 6111 is located above the first opening 621.

[0045] In this embodiment of the application, the first end of the elastic structure 612 abuts against the side of the first limiting end 6111 near the connecting post 6112, the second end of the elastic structure 612 abuts against the limiting part, and the second limiting end has a first preset distance from the bottom of the first opening 621.

[0046] Specifically, the first end and the second end are set opposite to each other. The material, specific structure and length of the elastic structure 612 can be selected according to actual needs. The first preset distance can be set according to actual needs. It should be noted that the first preset distance is greater than or equal to the distance between the upper surface of the buffer part 61 in the released state and the upper surface of the wafer placement area 5, so as to ensure that the upper surface of the buffer part 61 in the pressed state does not exceed the upper surface of the wafer placement area 5.

[0047] In this embodiment, the limiting structure is provided with a second opening adapted to the main body 62. The top of the main body 62 is disposed in the second opening. The first end of the elastic structure 612 abuts against the bottom of the second opening. The second end of the elastic structure 612 abuts against the side of the main body 62 facing the bottom of the second opening. The outer wall of the main body 62 is provided with a guide groove extending along the central axis of the second opening. The inner wall of the second opening is provided with a guide protrusion adapted to the guide groove. The guide protrusion is slidably disposed in the first guide groove.

[0048] Specifically, the length, width, and depth of the guide groove can be set according to actual needs, and the material, specific structure, and size of the guide protrusion can be set according to actual needs.

[0049] In this embodiment, multiple elastic limiting mechanisms 6 are arranged in an array.

[0050] Specifically, the multiple elastic limiting mechanisms 6 may not be arranged in an array, and the distance between two adjacent elastic limiting mechanisms 6 can be set according to actual needs.

[0051] In this embodiment of the application, the wafer bonding unit further includes a connection structure for connecting the upper bonding plate 2 and the lower bonding plate 1. Multiple connection structures are disposed around the wafer placement area 5 and are distributed in an array.

[0052] Specifically, the number, material, and structure of the connection structure can be set according to actual needs. For example, the connection structure is a fixing bolt fixed on the wafer bonding machine platform, which fixes the upper pressing plate 2 and the lower pressing plate 1 in the pressing state on the wafer bonding machine platform.

[0053] In this embodiment, the wafer placement area 5 is provided with mounting grooves 7 around the perimeter that are adapted to the main body 62, and the main body 62 and the mounting grooves 7 are detachably connected.

[0054] Specifically, the mounting slot 7 can be set on the lower bonding plate 1 or on the wafer bonding machine. The specific structure and size of the mounting slot 7 can be set according to actual needs.

[0055] In this embodiment of the application, the wafer bonding unit further includes a driving mechanism, which is connected to the upper bonding plate 2 and is used to drive the upper bonding plate 2 to move closer to or away from the lower bonding plate 1.

[0056] Specifically, the specific structure and size of the driving mechanism can be selected according to actual needs. In the direction perpendicular to the plane where the wafer placement area 5 is located, the upper pressing plate 2 is driven to move up and down, so that the upper pressing plate 2 moves closer to or away from the lower pressing plate 1.

[0057] Specifically, the elastic limiting mechanism 6 is used to limit the wafer 4 located in the wafer placement area 5. For example, a bolt is embedded in a sleeve-type structure, and a spring structure is set in the gap between the bolt and the sleeve, making the top of the elastic limiting mechanism 6 a movable part. When the machine malfunctions and the wafer 4 is placed above the elastic limiting mechanism 6, due to the movable compressibility of the top of the elastic limiting mechanism 6, when the upper pressing plate 2 presses down on the wafer 4, the top of the elastic limiting mechanism 6 moves downward under the downward pressure from the wafer 4 until the plane where the top of the elastic limiting mechanism 6 is located does not exceed the plane where the wafer placement area 5 is located. When the bottom surface of the wafer 4 is flush with the upper surface of the wafer placement area 5, the force on the wafer 5 from the buffer part 61 is small, avoiding the problem of concentrated stress and thus avoiding damage to the wafer 4. This reduces the impact of abnormal wafer 4 position. The wafer 4 that is not properly pressed can be recycled and pressed again, thereby improving the product yield.

[0058] In summary, the wafer bonding unit provided by this utility model, by setting multiple spaced elastic limiting mechanisms embedded around the wafer placement area on the lower pressing plate, has a buffer portion in the released elastic limiting mechanism having an upper surface higher than the upper surface of the wafer placement area, thus limiting the wafer located in the wafer placement area. When the upper and lower pressing plates work together to press the wafer, the upper surface of the buffer portion in the pressed state does not exceed the upper surface of the wafer placement area. When the machine malfunctions and the wafer is placed above the buffer portion, the upper pressing plate presses down on the wafer during the wafer pressing process. The buffer portion moves downward due to the downward pressure from the wafer until the upper surface of the buffer portion does not exceed the upper surface of the wafer placement area. When the bottom surface of the wafer is flush with the upper surface of the wafer placement area, the force on the wafer from the buffer portion is small, thereby avoiding wafer breakage caused by stress concentration. Wafers that are not properly pressed can be recycled and re-pressed, thereby improving product yield. Therefore, this utility model effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0059] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. A wafer bonding unit, characterized in that, include: A pressure plate is fixed on a wafer bonding machine, and the pressure plate includes at least a wafer placement area; Multiple spaced elastic limiting mechanisms are embedded around the wafer placement area. Each elastic limiting mechanism includes a buffer part and a main body part. The main body part is embedded around the lower pressure plate. The buffer part is elastically connected to the top of the main body part. When the buffer part is in the released state, its upper surface is higher than the upper surface of the wafer placement area. When the buffer part is in the pressed state, its upper surface does not exceed the upper surface of the wafer placement area. The upper laminating plate is located above the lower laminating plate and is adapted to the lower laminating plate. It is used to work together with the lower laminating plate to press the wafer located in the wafer placement area.

2. The wafer bonding unit according to claim 1, characterized in that: The buffer section includes a limiting structure and an elastic structure, and the limiting structure is connected to the top of the main body.

3. The wafer bonding unit according to claim 2, characterized in that: The limiting structure includes a first limiting end and a second limiting end disposed opposite to each other, and a connecting post that fixes the first limiting end and the second limiting end together. The elastic structure is sleeved around the connecting post.

4. The wafer bonding unit according to claim 3, characterized in that: The main body is provided with a first opening adapted to the second limiting end, and the inner wall of the first opening is provided with a limiting part adapted to the connecting post, the limiting part being located above the second limiting end.

5. The wafer bonding unit according to claim 4, characterized in that: The first end of the elastic structure abuts against the side of the first limiting end near the connecting post, the second end of the elastic structure abuts against the limiting part, and the second limiting end has a first preset distance from the bottom of the first opening.

6. The wafer bonding unit according to claim 2, characterized in that: The limiting structure has a second opening adapted to the main body, the top of the main body is disposed in the second opening, the first end of the elastic structure abuts against the bottom of the second opening, the second end of the elastic structure abuts against the side of the main body facing the bottom of the second opening, the outer wall of the main body is provided with a guide groove extending along the central axis of the second opening, the inner wall of the second opening is provided with a guide protrusion adapted to the guide groove, and the guide protrusion is slidably disposed in the first guide groove.

7. The wafer bonding unit according to claim 1, characterized in that: The multiple elastic limiting mechanisms are arranged in an array.

8. The wafer bonding unit according to claim 1, characterized in that: The wafer bonding unit further includes a connection structure for connecting the upper bonding plate and the lower bonding plate. A plurality of the connection structures are disposed around the wafer placement area and are distributed in an array.

9. The wafer bonding unit according to claim 1, characterized in that: The wafer placement area is provided with mounting grooves around the main body, and the main body is detachably connected to the mounting grooves.

10. The wafer bonding unit according to claim 1, characterized in that: The wafer bonding unit further includes a driving mechanism connected to the upper bonding plate, which is used to drive the upper bonding plate to move closer to or away from the lower bonding plate.

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