Bonding head, bonding apparatus, and bonding method
By designing an adsorption structure for the bonding head, the gas release time is delayed and the bonding wave diffusion is assisted, thus solving the problem of bubble defects caused by deformation in semiconductor bonding and improving bonding accuracy and yield.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- WUHAN XINXIN SEMICON MFG CO LTD
- Filing Date
- 2026-01-22
- Publication Date
- 2026-06-09
AI Technical Summary
In semiconductor bonding processes, deformation of the first substrate to be bonded due to the influence of preceding processes can lead to incomplete gas removal, resulting in bubble defects that affect bonding accuracy and yield.
The bonding head and device are specially designed, and the adsorption structure is provided with a through adsorption hole. The width of the hole first decreases and then increases along the direction of the orientation, which delays the gas release time. The thrust of the adsorption structure assists the diffusion of the bonding wave, thereby improving the bonding stability and accuracy.
By delaying gas release time and using thrust-assisted bonding wave diffusion, bubble defects are reduced, thereby improving the stability and yield of the bonding process.
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Figure CN122180358A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of semiconductor manufacturing, and in particular to a bonding head, bonding apparatus and bonding method. Background Technology
[0002] Semiconductor bonding processes are used to bond a first substrate (e.g., a wafer, a chip) that has undergone several processing steps to a second substrate (e.g., a wafer, a chip) to form a single bond. In semiconductor bonding, due to the influence of preceding processes, the first substrate to be bonded may deform before being bonded to the second substrate. This can lead to bubble defects between the two semiconductor devices during bonding, caused by incomplete gas removal, resulting in lower bonding accuracy and affecting the yield of the bonded products. Summary of the Invention
[0003] This application provides a bonding head, a bonding device, and a bonding method, which can improve the bonding accuracy and production yield of the bonding process.
[0004] To address the aforementioned technical problems, this application provides a bonding head applied to a bonding apparatus for bonding a first substrate to a second substrate. The bonding head includes: a bonding head body; and an adsorption structure disposed on one side of the bonding head body, including a bottom surface for adsorbing the first substrate and a top surface opposite to the bottom surface. The adsorption structure has at least two adsorption holes penetrating the adsorption structure. Each adsorption hole forms a first opening on the top surface and a second opening on the bottom surface. The width of each adsorption hole first decreases and then increases along the direction from the first opening to the second opening.
[0005] In some embodiments, each of the adsorption pores includes a narrow portion with a width smaller than the other portions of the adsorption pore; the distance between the narrow portions of at least two of the adsorption pores and the bottom surface gradually decreases in the direction from the edge region of the adsorption structure to the center region of the adsorption structure.
[0006] In some embodiments, the line connecting the center points of at least two of the narrow portions of the adsorption holes forms a convex surface protruding toward the bottom surface.
[0007] In some embodiments, the first width of the first opening of each adsorption pore and the second width of the corresponding second opening are equal.
[0008] In some embodiments, the first width of each of the adsorption pores is equal; or, in a direction from the edge of the adsorption structure toward the center of the adsorption structure, the first width of at least two of the adsorption pores gradually decreases.
[0009] In some embodiments, the adsorption structure includes a boss disposed on the bottom surface of the adsorption structure and located at the center of the adsorption structure, and the boss is used to contact the central region of the first substrate, so that when the bonding head adsorbs the first substrate, the central region of the first substrate is closer to the second substrate than the edge region of the first substrate.
[0010] In some embodiments, the first substrate is a chip, and the thickness of the chip is less than 100 μm.
[0011] To address the aforementioned technical problems, this application further provides a bonding apparatus, comprising: a support stage for supporting the second substrate; and a bonding head as described in any of the preceding claims for bonding the first substrate to the second substrate.
[0012] To address the aforementioned technical problems, this application also provides a bonding method for bonding a first substrate to a second substrate. The method includes: picking up the first substrate using an adsorption structure, the adsorption structure including a bottom surface for adsorbing the first substrate and a top surface opposite to the bottom surface, the adsorption structure having at least two adsorption holes penetrating the adsorption structure, each adsorption hole forming a first opening on the top surface and a second opening on the bottom surface, wherein the width of each adsorption hole first decreases and then increases along the direction from the first opening to the second opening; and releasing the adsorption force generated by the adsorption structure on the first substrate, so that the first substrate is bonded to the second substrate.
[0013] In some embodiments, each of the adsorption pores includes a narrow portion with a width smaller than the other portions of the adsorption pore; the distance between the narrow portions of at least two of the adsorption pores and the bottom surface gradually decreases in the direction from the edge of the adsorption structure to the center of the adsorption structure.
[0014] The bonding head provided in some embodiments of this application is applied to a bonding apparatus to bond a first substrate to a second substrate. The bonding head includes: a bonding head body; and an adsorption structure disposed on one side of the bonding head body, including a bottom surface for adsorbing the first substrate and a top surface opposite to the bottom surface. The adsorption structure has at least two adsorption holes penetrating the structure. Each adsorption hole forms a first opening on the top surface and a second opening on the bottom surface. The width of each adsorption hole first decreases and then increases along the direction from the first opening to the second opening. This delays the time it takes for gas to pass through each adsorption hole during the bonding process from the first substrate to the second substrate, thereby improving the stability and accuracy of the bonding process and increasing the yield of the bonding process. Attached Figure Description
[0015] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein: Figure 1 This is a schematic diagram of the bonding device provided in some embodiments of this application; Figure 2 This is a schematic diagram of the bonding device provided in some embodiments of this application; Figure 3 This is a schematic diagram of the bonding device provided in some embodiments of this application; Figure 4A This is a bottom view of the adsorption structure provided in one embodiment of the present application, on the side away from the bonding head body; Figure 4B A bottom view of the adsorption structure away from the bonding head body in another embodiment of this application; Figure 5 for Figure 4A A cross-sectional schematic diagram of one embodiment of the adsorption structure along the AA' direction; and Figure 6 This is a flowchart illustrating the bonding method provided in some embodiments of this application. Detailed Implementation
[0016] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.
[0017] The terms "first" and "second" in this application are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified in some embodiments.
[0018] In the embodiments of this application, all directional indicators (such as up, down, left, right, front, back, top, bottom, etc.) are only used to explain the relative positional relationship and movement of each component in a specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.
[0019] Furthermore, the terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus.
[0020] Unless otherwise defined, the term "approximately" as used in this application can be understood, in relation to numerical quantities or quantitative relationships, as a range of approximately ±15% of a certain value.
[0021] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.
[0022] Semiconductor bonding processes are used to bond a first substrate (e.g., a wafer, a chip) that has undergone several processing steps to a second substrate (e.g., a wafer, a chip) to form a single bond. In semiconductor bonding, due to the influence of preceding processes, the first substrate to be bonded may deform before being bonded to the second substrate. This can lead to bubble defects between the two semiconductor devices during bonding, caused by incomplete gas removal, resulting in lower bonding accuracy and affecting the yield of the bonded products.
[0023] Currently, the commonly used bonding methods include the following three types: wafer-to-wafer (W2W), chip-to-wafer (D2W), and chip-to-chip (C2W). In D2W bonding, due to the small thickness and weak rigidity of the chip, it is prone to movement during bonding, making the D2W bonding process difficult to control and thus affecting its bonding accuracy.
[0024] To address the aforementioned technical problems, this application provides a bonding head and a bonding apparatus. See also... Figures 1-3 , Figure 1 This is a schematic diagram of the bonding device provided in some embodiments of this application; Figure 2 This is a schematic diagram of the bonding device provided in some embodiments of this application; Figure 3 This is a schematic diagram of the bonding device provided in some embodiments of this application.
[0025] like Figure 1-3As shown, the bonding apparatus 10 includes a bonding head 100 and a support stage 200 for bonding a first substrate 20 to a second substrate 30. The bonding head 100 includes a bonding head body 110 and an adsorption structure 120. The adsorption structure 120 is disposed on one side of the bonding head body 110. This adsorption structure 120 is used to adsorb the first substrate 20, facilitating the bonding head 100 to carry the first substrate 20 to the second substrate 30 for bonding. The support stage 200 is used to support the second substrate 30. During the bonding process between the first substrate 20 and the second substrate 30, the adsorption structure 120 of the bonding head 100 adsorbs the first substrate 20 and aligns the first substrate 20 with the second substrate 30 on the support stage 200. After alignment, the bonding head 100 drives the middle region of the first substrate 20 to contact the second substrate 30 first, and then the adsorption structure 120 of the bonding head 100 releases the adsorption force on the first substrate 20. Therefore, the bonding wave generated between the first substrate 20 and the second substrate 30 diffuses to bond the first substrate 20 and the second substrate 30.
[0026] In some embodiments, the second substrate 30 includes a bonding region 31 to be bonded to the first substrate 20, and a first alignment mark (not shown) may be provided on the bonding region 31. Correspondingly, a second alignment mark (not shown) may be provided on the first substrate 20. The bonding apparatus 10 also includes an optical component (not shown). During the alignment process of the first substrate 20 and the second substrate 30, the optical component may capture the second alignment mark on the first substrate 20 and the first alignment mark on the bonding region 31 of the second substrate 30, respectively, so as to align the first substrate 20 and the bonding region 31 of the second substrate 30. In other embodiments, the bonding apparatus 10 may also use other methods to align the first substrate 20 and the bonding region 31 of the second substrate 30, which is not limited here.
[0027] In some embodiments, the first substrate 20 is a chip, and the second substrate 30 is a wafer. The chip has a thickness of less than 100 μm, such as 90 μm, 80 μm, or 70 μm. In other embodiments, both the first substrate 20 and the second substrate 30 may be chips of other thicknesses. Of course, in some embodiments, both the first substrate 20 and the second substrate 30 may be wafers or chips; this is not a limitation.
[0028] See Figures 4A-5 , Figure 4A This is a bottom view of the adsorption structure provided in one embodiment of the present application, on the side away from the bonding head body; Figure 4B A bottom view of the adsorption structure away from the bonding head body in another embodiment of this application; Figure 5 for Figure 4A A cross-sectional schematic diagram of one embodiment of the adsorption structure along the AA' direction.
[0029] like Figures 4A-5 As shown, in some embodiments of this application, the adsorption structure 120 includes a top surface 121 and a bottom surface 122 disposed opposite to each other. The top surface 121 is connected to the bonding head body 110. The bottom surface 122 serves as the adsorption surface of the bonding head 100 for adsorbing the first substrate 20. The adsorption structure 120 also has at least two adsorption holes 123 penetrating through the adsorption structure 120. Each adsorption hole 123 forms a first opening 1231 on the top surface 121 and a second opening 1232 on the bottom surface 122. In some embodiments, the adsorption structure 120 adsorbs the first substrate 20 by vacuum adsorption. When the adsorption structure 120 adsorbs the first substrate 20, the gas between the first substrate 20 and the bonding head 100 enters through the second opening 1232 and is extracted to a vacuum device (such as a vacuum pump) after passing through the first opening 1231. When the adsorption structure 120 bonds the first substrate 20 to the second substrate 30, the adsorption structure 120 releases the adsorption force on the first substrate 20 by inputting gas. At this time, the gas enters from the first opening 1231 of the adsorption hole 123 and flows out of the adsorption structure 120 through the second opening 1232 to release the gas.
[0030] The shape of the adsorption hole 123 on the first cross section can be circular, oriented, or other shapes. The first cross section is parallel to the surface of the first substrate 20, the surface of the second substrate 30, or the bonding interface between the first substrate 20 and the second substrate 30. This application does not impose specific limitations.
[0031] See Figure 5 On the second cross section, along a first direction x pointing from the first opening 1231 of the adsorption hole 123 to the second opening 1232, the width of each adsorption hole 123 first decreases and then increases. Therefore, when the adsorption structure 120 releases its adsorption force on the first substrate 20, the gas released through the adsorption hole 123 from the second opening 1232 will encounter resistance, thus delaying the time it takes for the gas to pass through each adsorption hole 123. The second cross section is perpendicular to the surface of the first substrate 20, the surface of the second substrate 30, or the bonding interface between the first substrate 20 and the second substrate 30.
[0032] In some embodiments, the width of the adsorption holes 123 at different positions of the adsorption structure 120 along the first direction x can be varied according to the deformation of the first substrate 20, thereby allowing the time for the adsorption structure 120 to release the first substrate 20 at different positions to be set. Furthermore, the gas released from the second opening 1232 of the adsorption holes 123 by the adsorption structure 120 generates a thrust on the first substrate 20. Depending on the width variation of the adsorption holes 123 at different positions of the adsorption structure 120 along the first direction x, the time for the adsorption structure 120 to generate the thrust at different positions is also delayed to varying degrees. By setting the width variation of the adsorption holes 123 at different positions of the adsorption structure 120 along the first direction x, the time for the adsorption structure 120 to generate the thrust at different positions can be set, thereby achieving that the thrust generated by the adsorption structure 120 at different positions is generated sequentially with the diffusion of the bonding wave between the first substrate 20 and the second substrate 30, thereby assisting the diffusion of the bonding wave between the first substrate 20 and the second substrate 30 and improving the stability and bonding accuracy of the bonding process. See also Figures 4A-4B In some embodiments, at least two adsorption pores 123 are arrayed in the adsorption structure 120. The at least two adsorption pores 123 are arranged in a rectangular pattern. In some embodiments, the rectangular arrangement includes at least two nested sub-rectangles formed around the center of the adsorption structure 120, wherein the center line connecting the adsorption pores 123 within the same sub-rectangle forms a rectangle. In other embodiments, the at least two adsorption pores 123 may also be arranged in other shapes, such as a circular or spiral arrangement. In some embodiments, the adsorption structure 120 is provided with two sets of nested adsorption pores 123; in other embodiments, the adsorption structure 120 may include three, four, five, or other sets of nested adsorption pores 123.
[0033] See also Figure 5 In some embodiments, each adsorption hole 123 includes a narrow portion 1233 with a width smaller than the other portions of the adsorption hole 123. When the adsorption structure 120 releases its adsorption force on the first substrate 20, the gas in the adsorption hole 123 is blocked at the narrow portion 1233, thereby delaying the time for the gas to be released from the second opening 1232. When the height of the narrow portion 1233 along the first direction x is different in different adsorption holes 123, the time for the gas to be released from the second opening 1232 of the different adsorption holes 123 is also different. That is, by setting the height of the narrow portion 1233 along the first direction x in different adsorption holes 123, the time for the adsorption structure 120 to generate thrust at different positions can be set, thereby assisting the diffusion of the bonding wave between the first substrate 20 and the second substrate 30.
[0034] Understandably, the closer the narrow portion 1233 of the adsorption hole 123 is to the second opening 1232, that is, the smaller the distance between the narrow portion 1233 and the bottom surface 122, the shorter the time that the gas is delayed when it is released from the second opening 1232, that is, the earlier the thrust generated at the adsorption hole 123 when the adsorption structure 120 releases the adsorption force on the first substrate 20.
[0035] See Figures 4A-5 In some embodiments, in a second direction y from the edge region of the adsorption structure 120 to the center region of the adsorption structure 120, the distance between the narrow portion 1233 of at least two adsorption holes 123 and the bottom surface 122 gradually decreases. This causes the adsorption structure 120 to release its adsorption force on the first substrate 20 during the bonding process, when the first substrate 20 is released from the bonding head 100 and bonded to the second substrate 30. The thrust generated in the center region of the adsorption structure 120 occurs earlier than the thrust generated in the edge region of the adsorption structure 120, and the thrust generated by the adsorption structure 120 gradually diffuses from its center region to its edge region. In this way, during the bonding process of the first substrate 20 and the second substrate 30, under the action of the thrust generated by the adsorption structure 120, the middle region of the first substrate 20 contacts the second substrate 30 before the edge region of the first substrate 20. This helps the bonding wave between the first substrate 20 and the second substrate 30 to gradually diffuse from the center region of the first substrate 20 to the edge region of the first substrate 20. This alleviates the deformation of the first substrate 20 before bonding, and during the bonding process, the edge area of the first substrate 20 contacts the second substrate 30 in advance to generate a bonding wave, which diffuses simultaneously with the bonding wave located in the center area of the first substrate 20. This results in the incomplete exhaust of gas between the first substrate 20 and the second substrate 30, causing bubble defects and thus improving the yield of the bonding process.
[0036] like Figure 5 As shown, in some embodiments, the line connecting the center points of the narrow portions 1233 of at least two adsorption holes 123 of the adsorption structure 120 forms a convex surface protruding towards the bottom surface 122. In some embodiments, this convex surface is, for example, arc-shaped or hemispherical. This allows the thrust generated by the adsorption structure 120 to diffuse uniformly from the central region of the adsorption structure 120 to the edge region of the adsorption structure 120. This further improves the stability of the bonding wave diffusion between the first substrate 20 and the second substrate 30 during the bonding process and further reduces the generation of bubble defects. In other embodiments, the narrow portions 1233 of at least two adsorption holes 123 may be located in other positions depending on the deformation of the first substrate 20 and the second substrate 30, and different process conditions.
[0037] In other possible embodiments, the distance between the narrow portions 1233 of at least two adsorption holes 123 and the bottom surface 122 may gradually increase in the second direction y from the edge region of the adsorption structure 120 to the central region of the adsorption structure 120. The line connecting the center points of the narrow portions 1233 of the at least two adsorption holes 123 of the adsorption structure 120 forms a convex surface protruding towards the top surface 121.
[0038] See Figures 1-4B In some embodiments, the adsorption structure 120 further includes a boss 124, which is disposed on the bottom surface 122 of the adsorption structure 120 and located at the center of the adsorption structure 120. The boss 124 is used to contact the central region of the first substrate 20. When the bonding head 100 adsorbs the first substrate 20 through the adsorption structure 120, the boss 124 first contacts the central region of the first substrate 20, so that the central region of the first substrate 20 is farther away from the adsorption structure 120 than the edge region of the first substrate 20, that is, the central region of the first substrate 20 is closer to the support stage 200 and the second substrate 30 than the edge region of the first substrate 20. As a result, when the bonding head 100 moves the first substrate 20 toward the second substrate 30, the central region of the first substrate 20 contacts the second substrate 30 first and generates a bonding wave before the edge region of the first substrate 20, thereby further mitigating bubble defects generated during the bonding process and improving the bonding yield.
[0039] See Figure 5 In some embodiments, the first width d1 of the first opening 1231 of each adsorption hole 123 and the second width d2 of the corresponding second opening 1232 are equal. This makes the adsorption force generated during the adsorption process of the adsorption structure 120 and the thrust generated during the release process more stable, thereby making the adsorption and release processes of the bonding head 100 on the first substrate 20 more stable. In other embodiments, the first width d1 of the first opening 1231 of each adsorption hole 123 and the second width d2 of the corresponding second opening 1232 may not be equal. Wherein, the first width d1 is the opening width of the first opening 1231 on the second cross section, and the second width d2 is the opening width of the second opening 1232 on the second cross section.
[0040] like Figure 4A As shown, in some embodiments, the first width d1 of each adsorption hole 123 is equal, that is, the second width d2 of each adsorption hole 123 is equal. Therefore, the adsorption force generated by the adsorption structure 120 on the first substrate 20 at each adsorption hole 123 is equal.
[0041] like Figure 4BAs shown, in some embodiments, in the second direction y from the edge region of the adsorption structure 120 towards the center region of the adsorption structure 120, the first width d1 of at least two adsorption pores 123 gradually decreases, that is, in the second direction y, the second width d2 of at least two adsorption pores 123 gradually decreases. Figure 4B In the adsorption structure 120, the second width d2 of a group of adsorption holes 123 near the center region is smaller than the second width d2 of a group of adsorption holes 123 near the edge region. This results in a lower adsorption force at the adsorption holes 123 in the center region than at the edge region. Consequently, compared to the edge region, releasing less gas into the center region of the adsorption structure 120 is sufficient to separate the center region of the adsorption structure 120 from the middle region of the first substrate 20.
[0042] With the above configuration, by adjusting the width of the adsorption structure 120 and coordinating with the protrusion 124, the central region of the first substrate 20 is closer to the second substrate 30 of the support stage 200 than the edge region of the first substrate 20. This causes the central region of the first substrate 20 to contact the second substrate 30 first and generate a bonding wave, thereby further mitigating bubble defects generated during the bonding process and improving the bonding yield.
[0043] In other embodiments, the widths of at least two adsorption holes 123 may be arranged to other sizes depending on the deformation of the first substrate 20 and the second substrate 30, as well as different process conditions. For example, when the deformation of a certain area of the first substrate 20 is large, the size of the second width d2 of the adsorption hole 123 in the corresponding area of the adsorption structure 120 can be increased, thereby increasing the adsorption force in that area, improving the deformation of that area of the first substrate 20, alleviating the bubble defects generated during the bonding process due to the deformation of the first substrate 20 before bonding, and improving the bonding yield.
[0044] To address the aforementioned technical problems, this application also provides a bonding method. See [link to relevant documentation]. Figure 6 , Figure 6 This is a schematic flowchart illustrating a bonding method provided in some embodiments of this application. This bonding method can be applied to the bonding head 100 and bonding device 10 in any of the above embodiments. The bonding method includes: Step S1: Pick up the first substrate using an adsorption structure. The adsorption structure includes a bottom surface for adsorbing the first substrate and a top surface opposite to the bottom surface. The adsorption structure has at least two adsorption holes that penetrate the adsorption structure. Each adsorption hole has a first opening on the top surface and a second opening on the bottom surface. The width of each adsorption hole first decreases and then increases along the direction from the first opening to the second opening.
[0045] See Figure 1 The bonding head 100 provides a first substrate 20 and a second substrate 30 to be bonded. The first substrate 20 is adsorbed by the adsorption structure 120 of the bonding head 100, and the second substrate 30 is supported by the support stage 200. The bonding head 100 includes a bonding head body 110 and an adsorption structure 120, which is disposed on one side of the bonding head body 110.
[0046] Further, see Figures 4A-5 The adsorption structure 120 includes a top surface 121 and a bottom surface 122 disposed opposite to each other. The top surface 121 is connected to the bonding head body 110, and the bottom surface 122 serves as the adsorption surface of the bonding head 100. The adsorption structure 120 also has at least two adsorption holes 123 penetrating through the adsorption structure 120. Each adsorption hole 123 forms a first opening 1231 on the top surface 121 and a second opening 1232 on the bottom surface 122.
[0047] Step S2: Release the adsorption force generated by the adsorption structure on the first substrate so that the first substrate is bonded to the second substrate.
[0048] See Figures 1-2 The bonding head 100 moves the first substrate 20 to align it with the second substrate 30 on the support stage 200. After confirming the alignment, the bonding head 100 moves the first substrate 20 closer to the second substrate 30 so that a portion of the first substrate 20 contacts the bonding area 31 of the second substrate 30.
[0049] In some embodiments, the adsorption structure 120 includes a boss 124 disposed on the bottom surface 122 of the adsorption structure 120 and located at the center of the adsorption structure 120. The boss 124 is used to contact the central region of the first substrate 20. When the bonding head 100 adsorbs the first substrate 20 through the adsorption structure 120, the boss 124 contacts the central region of the first substrate 20, so that the central region of the first substrate 20 is closer to the support stage 200 and the second substrate 30 than the edge region of the first substrate 20. This causes the central region of the first substrate 20 to contact the second substrate 30 first and generate a bonding wave before the edge region of the first substrate 20, thereby further mitigating bubble defects generated during the bonding process and improving the bonding yield.
[0050] See Figure 3After the central region of the first substrate 20 comes into contact with the bonding region 31 of the second substrate 30 and a bonding wave is generated, the adsorption force generated by the adsorption structure 120 on the first substrate 20 is released, causing the bonding wave to diffuse from the central region of the first substrate 20 to the edge region of the first substrate 20. During this process, gas is released sequentially from the second opening 1232 of at least two adsorption holes 123 of the adsorption structure 120, from the central region of the adsorption structure 120 to the edge region of the adsorption structure 120, so that the adsorption structure 120 generates a thrust to assist the diffusion of the bonding wave on the first substrate 20.
[0051] See Figure 5 In this configuration, along the first direction x from the first opening 1231 of the adsorption hole 123 to the second opening 1232, the width of each adsorption hole 123 first decreases and then increases. Thus, when the adsorption structure 120 releases its adsorption force on the first substrate 20, the gas will encounter resistance when it is released from the adsorption hole 123 to the second opening 1232, thereby delaying the time for the gas to pass through each adsorption hole 123. Therefore, by setting the width of the adsorption holes 123 at different positions of the adsorption structure 120 along the first direction x, the time for the adsorption structure 120 to generate thrust at different positions can be set. This allows the thrust generated at different positions of the adsorption structure 120 to be generated sequentially as the bonding wave between the first substrate 20 and the second substrate 30 diffuses, thereby assisting the diffusion of the bonding wave between the first substrate 20 and the second substrate 30 and improving the stability and bonding accuracy of the bonding process.
[0052] See also Figure 5 In some embodiments, each adsorption hole 123 includes a narrow portion 1233 with a width smaller than the other portions of the adsorption hole 123. When the adsorption structure 120 releases its adsorption force on the first substrate 20, the gas in the adsorption hole 123 is blocked at the narrow portion 1233, thereby delaying the time for the gas to be released from the second opening 1232. Thus, by setting the height of the narrow portion 1233 in different adsorption holes 123 along the first direction x, the time for the adsorption structure 120 to generate thrust at different positions can be set, thereby assisting the diffusion of the bonding wave between the first substrate 20 and the second substrate 30.
[0053] See Figures 4A-5In some embodiments, in a second direction y from the edge region of the adsorption structure 120 to the center region of the adsorption structure 120, the distance between the narrow portion 1233 of at least two adsorption holes 123 and the bottom surface 122 gradually decreases. This causes the thrust generated by the adsorption structure 120 to gradually diffuse from its center region to its edge region when the first substrate 20 is released from the bonding head 100 and bonded to the second substrate 30 during the bonding process. In this way, during the bonding process of the first substrate 20 and the second substrate 30, under the action of the thrust generated by the adsorption structure 120, the middle region of the first substrate 20 contacts the second substrate 30 before its edge region. This allows the bonding wave between the first substrate 20 and the second substrate 30 to gradually diffuse from the center region of the first substrate 20 to its edge region. This alleviates bubble defects generated between the first substrate 20 and the second substrate 30 during the bonding process and improves the yield of the bonding process.
[0054] In some embodiments, the bonding method further includes, before performing step S1, setting at least two narrow portions 1233 of the adsorption holes 123 at positions along the first direction x, based on the deformation of the first substrate 20 and the second substrate 30, and different process conditions. For example, in some embodiments, the line connecting the center points of the narrow portions 1233 of the at least two adsorption holes 123 of the adsorption structure 120 may be set as a convex surface protruding towards the bottom surface 122, thereby causing the thrust generated by the adsorption structure 120 to diffuse uniformly from the central region of the adsorption structure 120 to the edge region of the adsorption structure 120. This further improves the stability of the bonding wave diffusion between the first substrate 20 and the second substrate 30 during the bonding process and further reduces the generation of bubble defects.
[0055] The bonding head 100 provided in this application is applied to the bonding apparatus 10 to bond a first substrate 20 to a second substrate 30. The bonding head 100 includes: a bonding head body 110; and an adsorption structure 120 disposed on one side of the bonding head body 110, including a bottom surface 122 for adsorbing the first substrate 20 and a top surface 121 disposed opposite to the bottom surface 122. The adsorption structure 120 has at least two adsorption holes 123 penetrating the adsorption structure 120. Each adsorption hole 123 has a first opening 1231 formed on the top surface 121 and a second opening 1232 formed on the bottom surface 122. The width of each adsorption hole 123 first decreases and then increases along the direction from the first opening 1231 to the second opening 1232. This delays the time it takes for gas to pass through each adsorption hole 123 during the bonding process from the first substrate 20 to the second substrate 30. As a result, when the adsorption structure 120 releases its adsorption force on the first substrate 20, it generates a thrust that assists in the diffusion of the bonding wave, thereby improving the stability and accuracy of the bonding process and increasing the yield of the bonding process.
[0056] The above are merely embodiments of this application and do not limit the scope of this patent application. Any equivalent structural or procedural changes made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of this application.
Claims
1. A bonding head, used in a bonding apparatus to bond a first substrate to a second substrate, characterized in that, The bonding head includes: Bonding head body; and An adsorption structure is disposed on one side of the bonding head body, including a bottom surface for adsorbing the first substrate and a top surface disposed opposite to the bottom surface. The adsorption structure has at least two adsorption holes penetrating the adsorption structure. Each adsorption hole forms a first opening on the top surface and a second opening on the bottom surface. In the direction from the first opening to the second opening, the width of each adsorption pore first decreases and then increases.
2. The bonding head according to claim 1, characterized in that, Each of the adsorption pores includes a narrow portion with a width smaller than the other portions of the adsorption pore; In the direction from the edge region of the adsorption structure to the center region of the adsorption structure, the distance between the narrow portion of at least two of the adsorption pores and the bottom surface gradually decreases.
3. The bonding head according to claim 2, characterized in that, The line connecting the center points of at least two of the narrow portions of the adsorption holes forms a convex surface protruding towards the bottom surface.
4. The bonding head according to claim 1, characterized in that, The first width of the first opening of each of the adsorption pores and the second width of the corresponding second opening are equal.
5. The bonding head according to claim 4, characterized in that, The first width of each of the adsorption pores is equal; or In the direction from the edge of the adsorption structure toward the center of the adsorption structure, the first width of at least two of the adsorption pores gradually decreases.
6. The bonding head according to claim 1, characterized in that, The adsorption structure includes a boss, which is disposed on the bottom surface of the adsorption structure and located at the center of the adsorption structure. The boss is used to contact the central region of the first substrate so that when the bonding head adsorbs the first substrate, the central region of the first substrate is closer to the second substrate than the edge region of the first substrate.
7. The bonding head according to claim 1, characterized in that, The first substrate is a chip, and the thickness of the chip is less than 100 μm.
8. A bonding device, characterized in that, include: A support platform for supporting the second substrate; as well as The bonding head as described in any one of claims 1-7 is used to bond the first substrate to the second substrate.
9. A bonding method for bonding a first substrate to a second substrate, characterized in that, The method includes: The first substrate is picked up using an adsorption structure. The adsorption structure includes a bottom surface for adsorbing the first substrate and a top surface disposed opposite to the bottom surface. The adsorption structure has at least two adsorption holes that penetrate the adsorption structure. Each adsorption hole forms a first opening on the top surface and a second opening on the bottom surface. The width of each adsorption hole first decreases and then increases along the direction from the first opening to the second opening. Release the adsorption force generated by the adsorption structure on the first substrate so that the first substrate is bonded to the second substrate.
10. The bonding method according to claim 9, characterized in that, Each of the adsorption pores includes a narrow portion with a width smaller than the other portions of the adsorption pore; In the direction from the edge of the adsorption structure toward the center of the adsorption structure, the distance between the narrow portion of at least two of the adsorption pores and the bottom surface gradually decreases.