Wafer alignment system, wafer bonding equipment and wafer bonding alignment method

Abstract

The invention provides a wafer alignment system, wafer bonding equipment and a wafer bonding alignment method. The wafer alignment system comprises a hot plate, a wafer bonding device and a wafer bonding alignment device, the limiting mechanism is arranged on the hot disc in a penetrating mode, the limiting mechanism comprises at least two supporting assemblies which jointly form a limiting area to support and limit a wafer, and the supporting assemblies ascend and descend in the direction perpendicular to the hot disc; the auxiliary alignment mechanism is arranged on the periphery of the hot plate in a surrounding mode, the auxiliary alignment mechanism comprises at least two pairs of supporting cantilevers, all the supporting cantilevers synchronously rotate to enter and exit from the limiting area, and the two supporting cantilevers of each pair of supporting cantilevers synchronously rotate in the opposite directions to enter and exit from the limiting area. According to the invention, bubbles and cavities formed between the first wafer and the second wafer in the bonding process of the first wafer and the second wafer are reduced.

Description

Technical Field

[0001] The present application relates to the technical field of semiconductor equipment, and particularly to a wafer alignment system, a wafer bonding equipment and a wafer bonding alignment method. Background Art

[0002] Wafer bonding is a wafer-level packaging technology used in the manufacturing of microelectromechanical systems (MEMS), nanoelectromechanical systems (NEMS), microelectronics, and optoelectronics to ensure a mechanically stable and sealed package. Generally, wafer bonding refers to aligning a wafer with a carrier wafer and then performing the bonding. Therefore, reliable alignment of the wafer and the carrier wafer in the wafer bonding process is a key prerequisite step in the wafer bonding process. For wafers and carrier wafers of the same size, during the alignment process in the process chamber of the bonding equipment, multiple ejector pins with arc-shaped limiting parts on the inner side are usually used to hold the lower edge of the carrier wafer, and then the wafer is transferred above the carrier wafer by a vacuum adsorption manipulator and placed on the surface of the carrier wafer after calibration.

[0003] With the continuous increase in the sizes of the wafer and the carrier wafer, air will remain between the wafer and the carrier wafer when the carrier wafer falls and fits the wafer. Even after the process chamber is evacuated to a vacuum state, voids will be formed between the wafer and the carrier wafer. Moreover, due to the inevitable warpage of the wafer and the carrier wafer, once the wafer and the carrier wafer are fitted, under the action of the van der Waals force, there may be bubbles between the wafer and the carrier wafer. Once the bubbles are locked between the wafer and the carrier wafer, even if the process chamber is later evacuated to a vacuum state, these bubbles still cannot escape from between the wafer and the carrier wafer and voids will be formed between the wafer and the carrier wafer, which will greatly affect the electrical and mechanical properties of the wafer after final bonding. Summary of the Invention

[0004] An embodiment of the present application discloses a wafer alignment system, including: a hot plate; a limiting mechanism disposed through the hot plate, wherein the limiting mechanism includes at least two support components that together form a limiting area to support and limit a wafer, and the support components move up and down in a direction perpendicular to the hot plate; an auxiliary alignment mechanism disposed around the hot plate, wherein the auxiliary alignment mechanism includes at least two pairs of support cantilevers, and all the support cantilevers rotate synchronously to enter and exit the limiting area, and the two support cantilevers of each pair of support cantilevers rotate synchronously in opposite directions to realize entering and exiting the limiting area.

[0005] In another embodiment of the present application, the limiting mechanism further includes a first driving mechanism, wherein the first driving mechanism drives the support components to move up and down in a direction perpendicular to the hot plate.

[0006] In another embodiment of the present application, the auxiliary alignment mechanism further includes a rotating mechanism matching the support cantilevers, and the rotating mechanism drives the support cantilevers to rotate.

[0007] In another embodiment of the present application, the wafer alignment system further includes a synchronization mechanism, which is connected to all the rotating mechanisms, and the synchronization mechanism synchronously drives all the rotating mechanisms, and further synchronously drives all the support cantilevers.

[0008] In another embodiment of the present application, the synchronization mechanism includes a synchronous connection component and a second driving mechanism. The synchronous connection component is simultaneously connected to the second driving mechanism and all the rotating mechanisms, and the second driving mechanism performs a telescopic movement in the vertical direction, so as to synchronously drive all the rotating mechanisms through the synchronous connection component.

[0009] In another embodiment of the present application, the synchronous connection component includes a frame body and a cross bar that horizontally spans the frame body. The second driving mechanism is connected to the cross bar, and all the rotating mechanisms are connected to the frame body.

[0010] In another embodiment of the present application, the rotating mechanism includes: a top block abutting against the frame body, a fixed seat slidably connected to the top block, a driving column, a moving block driven by the driving column and moving up and down in the vertical direction, a rotating shaft connecting the support cantilever, spiral guiding grooves symmetrically formed on the side walls of two rotating shafts on the same side of the hot plate, and guiding ends connected to two moving blocks on the same side of the hot plate and extending into the spiral guiding grooves.

[0011] The present application also discloses a wafer bonding device, including: a cavity, and a cover body connected to the cavity, wherein the cavity and the cover body accommodate the wafer alignment system in any of the foregoing embodiments.

[0012] The present application also discloses a wafer bonding alignment method implemented by using the above-mentioned wafer bonding device, which is characterized by including: Raise the support assembly to a first preset height, synchronously rotate all the support cantilevers to outside the limiting area, place a first wafer on the support assembly, and make the first wafer located in the limiting area, wherein the support assembly supports and limits the first wafer; Synchronously rotate all the support cantilevers to inside the limiting area, place a second wafer on the support cantilever, and make the second wafer located in the limiting area, wherein the support cantilever supports the second wafer, and the support assembly limits the second wafer; Lower the support assembly to a second preset height, heat the first wafer by the hot plate, and evacuate the cavity; Raise the support assembly to a third preset height, which is less than or equal to the first preset height, and simultaneously rotate all the support cantilevers out of the limiting area so that the second wafer falls onto the first wafer.

[0013] Compared with the prior art, the beneficial effects of the present application are as follows: In the present application, the wafer alignment system can perform an alignment action on two wafers of the same size through the design of the limiting mechanism and the auxiliary alignment mechanism. For the two wafers to be bonded, it is convenient to evacuate the air between the two wafers completely when performing the vacuum pumping operation, so that no bubbles are generated between the two wafers. Based on the wafer bonding equipment and the corresponding bonding method of the above wafer alignment system, the bonding quality can be greatly improved.

[0014] In the present application, the synchronization mechanism of the wafer alignment system can synchronously drive all the support cantilevers to rotate synchronously, and each pair of support cantilevers rotates in opposite directions, which can reduce the influence of friction during the support cantilever process on the stability of the wafer and ensure that the two wafers to be aligned do not shift.

[0015] The present application can be applied to wafer bonding equipment for various different sizes of wafers, such as 4-inch, 6-inch, 8-inch, 12-inch wafers. Brief Description of the Drawings

[0016] Figure 1 It is a perspective view of the wafer alignment system of the present application from one perspective, where Figure 1 the synchronous connection assembly is omitted; Figure 2 It is a perspective view of the wafer alignment system of the present application from another perspective, where Figure 2 the synchronous connection assembly is shown; Figure 3 It is a top view of the wafer alignment system; Figure 4 It is a partial side view of the wafer alignment system; Figure 5 It is a perspective view of the first driving mechanism for driving the support assembly to move up and down in the vertical direction; Figure 6 It is a perspective view of the support assembly; Figure 7 It is a perspective schematic diagram of the support assembly included in another variant of the wafer alignment system of the present application; Figure 8 It is a perspective schematic diagram of the auxiliary alignment mechanism; Figure 9 It is a partial enlarged view of the auxiliary alignment mechanism; Figure 10 It is a perspective schematic diagram of the wafer alignment system of the present application placing the first wafer; Figure 11 This is a three-dimensional schematic diagram of the wafer alignment system of the present application when placing the first wafer and the second wafer; Figure 12 This is a partially enlarged view of a support cantilever supporting the second wafer to isolate the first wafer from the second wafer; Figure 13 This is another three-dimensional schematic diagram of the wafer alignment system of the present application when placing the first wafer and the second wafer; Figure 14 This is another three-dimensional schematic diagram of the wafer alignment system of the present application when placing the first wafer and the second wafer; Figure 15 This is a three-dimensional view of the cover and the base of the wafer bonding equipment when they are closed; Embodiment

[0017] The present application will be described in detail below in conjunction with the embodiments shown in the drawings. However, it should be noted that these embodiments do not limit the present application. Any equivalent transformation or substitution in terms of function, method, or structure made by those of ordinary skill in the art based on these embodiments shall fall within the protection scope of the present application.

[0018] It should be understood that in the present application, the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the technical solution of the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the technical solution of the present application.

[0019] The present application discloses a wafer alignment system. Referring to Figure 1 and Figure 2 as shown, the wafer alignment system includes: a hot plate 20; a limiting mechanism 30 passing through the hot plate 20, and an auxiliary alignment mechanism 40 disposed around the hot plate 20.

[0020] The limiting mechanism 30 includes at least two support components 32 that jointly form a limiting area 200 for limiting and supporting the wafer, and a first driving mechanism 31 for driving the support components 32 to move up and down in a direction perpendicular to the hot plate 20. The limiting area 200 is adapted to the wafer, preferably circular.

[0021] The auxiliary alignment mechanism 40 includes at least two pairs of support cantilevers 42, and the support cantilevers 42 can enter and exit the limit area 200 by rotation. Those skilled in the art can understand that when the support cantilevers 42 enter and exit the limit area 200 by rotation, there is of course no interference with the limit mechanism 30. The auxiliary alignment mechanism 40 further includes a rotation mechanism 41 that matches the support cantilever 42, and the rotation mechanism 41 drives the support cantilever 42 to rotate. The wafer alignment system of the present application further includes a synchronization mechanism 5, and the synchronization mechanism 5 synchronously drives all the rotation mechanisms 41, thereby synchronously driving all the support cantilevers 42 to rotate synchronously.

[0022] Refer Figure 1 to Figure 3 As shown, in this embodiment, the hot plate 20 in the present application may include at least partially accommodating the first wafer 50 and a preheating groove 22 formed on the surface of the hot plate 20. The shape of the preheating groove 22 matches the wafer design, preferably circular. The support assembly 30 is disposed around the groove 22, and the limit area 200 formed by the support assembly 30 is preferably less than or equal to the preheating groove.

[0023] In the present application, the two pairs of support cantilevers 42 can rotate synchronously to enter and exit the limit area 200, and the two support cantilevers 42 included in each pair of support cantilevers 42 rotate synchronously in opposite directions. Specifically, refer to Figure 3 As shown, in an embodiment of the present application, the support cantilevers 42a and 42b are a pair of support cantilevers, and the support cantilevers 42c and 42d are a pair of cantilevers. When the support cantilevers 42a and 42b enter the limit area 200, they rotate along the directions a1 and a2 respectively. The support cantilever 42a rotates along the a1 direction, that is, counterclockwise, and the support cantilever 42b rotates along the a2 direction, that is, clockwise. When the support cantilevers 42a and 42b rotate in opposite directions, the friction forces generated by them are also opposite, and the generated friction forces can cancel each other out, thereby ensuring the stability of the wafer during the rotation process. Similarly, when the support cantilevers 42a and 42b leave the limit area 200, they rotate along the directions b1 and b2 respectively, that is, the support cantilever 42a rotates clockwise and the support cantilever 42b rotates counterclockwise. Similarly, when the support cantilevers 42c and 42d enter the limit area 200, they rotate along the directions a3 and a4 respectively, and when the support cantilevers 42c and 42d leave the limit area 200, they rotate along the directions b3 and b4 respectively, that is, the support cantilevers 42c and 42d rotate in opposite directions when entering or leaving the limit area 200.

[0024] Refer Figure 1 to Figure 5 and Figure 6As shown, the support component 32 includes a column 331 fixedly connected to the pallet 37, and a support member 332 movably connected to the column 331. The support member 332 includes a side wall 3321 and a step 3322. The side wall 3321 can limit the wafer, so that the wafer falls within the limiting area 200. Those skilled in the art can understand that the side wall 3321 faces the center of the limiting area 200, so that multiple support components 32 can form the limiting area 200. The step 3322 can support the wafer. When the wafer is placed on the support component 32, it is supported by the step 3322. Preferably, the side wall 3321 can be an arc-shaped side wall to better limit the wafer. The steps 3322 formed at the tops of the support components 32 are preferably located on the same horizontal plane, and the lengths of the columns 331 of the support components 32 to the support columns 36 are equal.

[0025] Those skilled in the art should understand that the shape of the support member 332 of the support component 32 in this application can be variable, that is, the support member 332 at least includes a step 3322 for supporting the wafer and a side wall 3321 for limiting the wafer.

[0026] As an alternative embodiment, refer to Figure 7 As shown, the present application also discloses another specific embodiment of a wafer alignment system. The main difference between it and the wafer alignment systems disclosed in the foregoing embodiments is that in this embodiment, only two support components 32 are required to implement the limiting area 200. The support component 32 includes a support member 342 and a column 341. The support member 342 includes a side wall 3421 and a step 3422. The bottom of the support member 342 is connected to two columns 341, and the lengths of the multiple columns 341 are equal and are connected to the pallet 37 as Figure 3 shown.

[0027] Those skilled in the art can understand that Figure 7 the support member 342 in Figure 6 and the support member 332 in

[0028] can both achieve the functions of supporting and limiting the wafer, but the specific shapes can be very different. The support component 32 of the limiting mechanism 30 in this application is intended to achieve the functions of supporting and limiting the wafer. The support can be achieved through the step, and the limitation can be achieved through the side wall. The specific shapes and settings can be flexibly set. Figure 7 Similarly, those skilled in the art can understand that the specific number of columns can be flexibly changed according to actual design requirements. For example,

[0029] Regarding the specific number of the support components 32, those skilled in the art should be aware that when the side wall 3321 is preferably arc-shaped, at least 2 support components 32 are required to enclose the limiting area. When the side wall 3321 is a plane, at least 3 support components 32 are required to enclose the limiting area. In this application, taking the number of the support components 32 being preferably 4 as an example, it can balance the cost and achieve the function of stably limiting and supporting the wafer.

[0030] Referring Figure 1 to Figure 5 as shown, the first driving mechanism 31 of this application can be a cylinder or a linear motor. The limiting mechanism 30 further includes a mounting seat 303 fixedly connected to the bottom plate 15. A bending portion 3031 is formed at the top of the mounting seat 303 close to the bottom plate 15. The bending portion 3031 is continuously penetrated by screws through the bending portion 3031 and the bottom plate 15. The first driving mechanism 31 drives the sliding seat 301 to move up and down along the Figure 5 direction of the double-headed arrow d in the figure. A track and a slider (not shown) that moves linearly along the track are provided between the sliding seat 301 and the mounting seat 303. In view of the fact that the sliding connection technology configured between the sliding seat 301 and the mounting seat 303 is a mature prior art, it is not described in detail in this embodiment.

[0031] The sliding seat 301 is connected to the plate body 302. A first mounting plate 304 is provided at the top of the plate body 302. The first mounting plate 304 forms a driving column 337 vertically arranged. The driving column 337 includes a connecting cylinder 3372 axially sleeved between a driving shaft 3372 and a driven shaft 3373. A second mounting plate 306 is provided above the first mounting plate 304, and a longitudinal bellows 305 is provided between the second mounting plate 306 and the first mounting plate 304. The second mounting plate 306 is fixed to the bottom of the bottom plate 15 by screws. The support plate 37 forms a threaded hole 3374, and the top end of the driven shaft 3373 is screwed and fixed to the threaded hole 3374. When the first driving mechanism 31 moves in the vertical direction, it drives the sliding seat 301 to perform a lifting movement relative to the mounting seat 303, and finally drives the support plate 37 to move up and down in the vertical direction to synchronously drive the four support columns 3 to move up and down in the vertical direction (that is, Figure 5 the direction of the double-headed arrow d in the figure).

[0032] Referring Figure 2As shown, the synchronization mechanism 5 disclosed in this application includes a synchronization connection component 51 and a second driving mechanism 52. The synchronization connection component 51 includes a frame body 511 and a cross bar 512 that horizontally spans the frame body 511. The synchronization connection component 51 is connected to the second driving mechanism 52 and all the rotating mechanisms 41 at the same time. Specifically, the frame body 511 is connected to all the rotating mechanisms 41, and the cross bar 512 is connected to the second driving mechanism 52. The second driving mechanism 52 makes a telescopic movement in the vertical direction, so as to synchronously drive all the rotating mechanisms 41 through the synchronization connection component 51, and further synchronously drive all the support cantilevers 42.

[0033] Those skilled in the art should be aware that the synchronization connection component 51 is not limited to the form shown in this embodiment. The synchronization connection component 51 can also be reasonably derived and understood as any deformed member that can uniformly conduct the driving force output by the second driving mechanism 52, as long as it can be connected to the second driving mechanism 52 and all the rotating mechanisms 41 at the same time. For example, the synchronization connection component 51 may only include the frame body 511, and the second driving mechanism 52 is connected to the frame body 511. The synchronization connection component 51 and the second driving mechanism 52 and all the rotating mechanisms 41 can be fixedly connected by screws or can be integrated. This application does not make any special limitations on the specific connection method..

[0034] Refer to Figure 4 、 Figure 8 and Figure 9 As shown, the rotating mechanism 41 includes: a top block 421 that abuts against the frame body 51, a fixed seat 422 that is slidably connected to the top block 421. A slider 423 is formed on the inner side of the top block 421 close to the fixed seat 422. The fixed seat 422 forms a guide rail in the vertical direction, and the slider 423 slides along the track. A driving column 426, a moving block 427 that is driven by the driving column 426 and moves up and down in the vertical direction (i.e., Figure 8 the direction of the double-headed arrow e in the figure), a rotating shaft 4301 that connects the support cantilever 42. Spiral guiding grooves 4300 are symmetrically formed on the side walls of the two rotating shafts 4301 on the same side of the hot plate 20. The guiding ends 4400 that extend into the spiral guiding grooves 4300 are connected to the two moving blocks 427 on the same side of the hot plate 20. A bending portion 4221 is formed at the top of the fixed seat 422, and the bending portion 4221 is fixedly connected to the bottom of the bottom plate 15 by screws. The driving column 426 includes a driving shaft 4263 that is vertically connected to the top block 421, a driven shaft 4261, and a connecting cylinder 4262 is axially sleeved between the driving shaft 4263 and the driven shaft 4261. The driving shaft 4263 is vertically connected to the top block 421, and the driving shaft 4263 is sleeved with a corrugated pipe 425 and a mounting plate 424. The mounting plate 424 and the corrugated pipe 425 are connected to the top block 421. The mounting plate 424 is provided with a plurality of through holes, and the mounting plate 424 is fixedly connected to the bottom of the bottom plate 15 by screws passing through the aforementioned through holes.

[0035] The drive shaft 4263 penetrates the bottom plate 15 in the vertical direction and extends into the bonding cavity 100. The passive shaft 4261 extends through the moving block 427 and is fixedly connected by screwing with the nut 4264. In this embodiment, by providing the bellows 425, the vibration generated by the vertical movement of the drive column 426 can be offset, thereby further improving the smoothness and stability of the rotation of the rotating shaft 4301 and the support cantilever 42, reducing the vibration generated by the support cantilever 42 on the second wafer 60 during the closing and opening processes, and thus avoiding the jumping of the second wafer 60 located above during the synchronous alignment process.

[0036] Exemplarily, the second driving mechanism 52 is abutted by the bottom plate 15. The second driving mechanism 52 forms a driving rod 521 that makes a telescopic movement in the vertical direction. The driving rod 521 uniformly transmits the driving force output by the second driving mechanism 52 to the frame 511 through the cross bar 512, so that the frame 511 synchronously drives the four top blocks 421 to slide relative to the fixed seat 422 in a horizontal posture. The end of the moving block 427 penetrates the horizontally arranged moving block 427, and the moving block 427 is connected to the guiding end 4400 through a connecting block. The connecting block includes: a first bending portion 4281 connecting the guiding end 4400 and a second bending portion 4282 connected to the moving block 427 by screws. The guiding end 4400 can be configured as a bearing, and the first bending portion 4281 forms a pin shaft (not shown) axially connecting the guiding end 4400. The pin shaft horizontally penetrates the screw hole 42811 of the first bending portion 4281 and connects the guiding end 4400, and the pin shaft and the first bending portion 4281 are fixed by a bolt assembly. A notch 4302 for movably connecting the support cantilever 42 is formed at the top of the rotating shaft 4301.

[0037] The rotating mechanism 41 further includes a holding bracket for keeping the height of the rotating shaft 4301 constant in the vertical direction during rotation. The holding bracket includes: a resisting plate 435, a vertical plate 429 perpendicular to the resisting plate 435 and parallel and perpendicular to the horizontal plane. A positioning block 431 for the rotating shaft 4301 to vertically penetrate is formed at the side of the vertical plate 429. A part of the bottom free end 4303 of the rotating shaft 4301 away from the support cantilever 4 extends into the resisting plate 435, and a bearing 433 is sleeved between the bottom free end 4303 and the resisting plate 435, so that the rotating shaft 4301 can rotate in the resisting plate 435 along the shaft 401 (or shaft 402), thereby driving the support cantilever 42 to Figure 8 rotate in the same horizontal plane in the direction of arrow a or arrow b in the figure. The resisting plate 435 is fixed inside the cavity and is fixedly connected to the bottom plate 15 by screws. When the driving rod 521 of the second driving mechanism 52 makes a telescopic movement in the vertical direction, the holding bracket is fixed while the rotating shaft 4301 rotates.

[0038] The specific manner in which the wafer alignment system disclosed in this application performs wafer alignment operations can be referred to Figures 10 - 12 .

[0039] Step 1, as Figure 10 shown, the first driving mechanism 31 synchronously drives the support assembly 32 of the limiting mechanism 30 to rise to the first preset height; all the support cantilevers 42 included in the auxiliary alignment mechanism 40 synchronously rotate to the first state; the first wafer 50 is placed on the support assembly 32 of the limiting mechanism 30, and it is ensured that the first wafer 50 is located in the circular limiting area 200, and the support assembly 32 supports and limits the first wafer 50.

[0040] Regarding the first preset height here, those skilled in the art should understand that the first preset height should be such that the limiting mechanism 30 can support and limit the first wafer 50 without affecting the subsequent support of the second wafer 60 on the first wafer 50 by the auxiliary alignment mechanism 40.

[0041] The first state here can be referred to as the open state, that is, all the support cantilevers 42 synchronously rotate outside the limiting area 200 so that the first wafer 50 will not interfere with the support cantilevers 42 during the placement process.

[0042] Step 2, as Figure 11 shown, all the support cantilevers 42 synchronously rotate to the second state; as Figure 12 shown, the second wafer 60 is placed on the support cantilevers 42, and it is ensured that the second wafer is located in the circular limiting area 200 surrounded by the limiting mechanism 30, so as to achieve a concentric circle pattern distribution of the first wafer 50 and the second wafer 60 from a top view angle.

[0043] The second state here can be referred to as the closed state, that is, all the support cantilevers 42 should synchronously rotate within the limiting area 200 so that the second wafer 60 can be supported.

[0044] Referring to Figure 12 shown, the limiting component 32 of the limiting mechanism 30 simultaneously limits both the first wafer 50 and the second wafer 60, that is, the first wafer 50 and the second wafer 60 are concentrically arranged, and the first wafer 50 and the second wafer 60 fall within the limiting area; the limiting component 32 of the limiting mechanism 30 only supports the first wafer 50, and the support cantilevers 42 only support the second wafer 60, so that there is a partial space between the first wafer 50 and the second wafer 60.

[0045] Based on the specific implementation manner of the wafer alignment system disclosed in the foregoing embodiments, this application also discloses a wafer bonding device.

[0046] Refer Figure 1 and Figure 15As shown, the present application discloses a wafer bonding device, such as Figure 1 As shown, the wafer bonding device may further include a support plate 11 that supports the hot plate 20 below the hot plate 20, and a clamping pad 111 between the support plate 11 and the bottom plate 15. As Figure 15 As shown, the wafer bonding device disclosed in the present application may further include a cavity 10 and an openable and closable cover 70 connected to the cavity, accommodating the wafer alignment system disclosed in any of the above specific embodiments. The wafer bonding device described in the present application can be a wafer bonding device of various sizes such as 4 inches, 6 inches, 8 inches, 12 inches, etc.

[0047] The present application Figure 15 As shown, the cover 70 is only a schematic diagram and does not represent a specific structure. The related design of the cover 70 is well-known to those skilled in the art, and the present application does not make specific limitations.

[0048] The wafer alignment system included in the wafer bonding device disclosed in the present application refers to that described in the foregoing embodiments and will not be elaborated herein.

[0049] Based on the wafer bonding device applying the above wafer alignment system, the present application also discloses a wafer alignment method. The following refers to Figures 10 to 14 As shown, the application of the wafer alignment system of the present application in the bonding device to perform the alignment operation steps on the first wafer 50 and the second wafer 60 will be described in detail.

[0050] Step 1, as Figure 10 As shown, the first driving mechanism 31 synchronously drives the support assembly 32 of the limiting mechanism 30 to rise to a first preset height; all the support cantilevers 42 included in the auxiliary alignment mechanism 40 synchronously rotate to a first state; the first wafer 50 is placed on the support assembly 32 of the limiting mechanism 30, and it is ensured that the first wafer 50 is located in the circular limiting area 200, and the support assembly 32 supports and limits the first wafer 50.

[0051] Regarding the first preset height here, those skilled in the art should understand that the first preset height should satisfy the condition that the limiting mechanism 30 can support and limit the first wafer 50 without affecting the subsequent support of the second wafer 60 on the first wafer 50 by the auxiliary alignment mechanism 40.

[0052] The first state here can be called the open state, that is, all the support cantilevers 42 synchronously rotate outside the limiting area 200 so that the first wafer 50 will not interfere with the support cantilevers 42 during the placement process.

[0053] Step 2, as Figure 11 As shown, all the support cantilevers 42 synchronously rotate to a second state; as Figure 12As shown, the second wafer 60 is placed on the support cantilever 42, and it is ensured that the second wafer is located in the circular limiting area 200 surrounded by the limiting mechanism 30, so as to realize that the first wafer 50 and the second wafer 60 are concentrically distributed from a top-down perspective.

[0054] The second state here can be called the closed state, that is, all the support cantilevers 42 should rotate synchronously within the limiting area 200 so as to support the second wafer 60.

[0055] Refer to Figure 12 As shown, the limiting component 32 of the limiting mechanism 30 limits both the first wafer 50 and the second wafer 60 at the same time, that is, the first wafer 50 and the second wafer 60 are concentrically arranged; the limiting component 32 of the limiting mechanism 30 only supports the first wafer 50, and the support cantilever 42 only supports the second wafer 60, so that there is a partial space between the first wafer 50 and the second wafer 60.

[0056] Step three, refer to Figure 13 , the limiting component 32 of the limiting mechanism 30 synchronously descends to the second preset height, and the first wafer 50 is preheated by the hot plate 20. At the same time, a vacuum pumping operation is performed to extract the air in the bonding cavity 10 to form a vacuum state in the bonding cavity 10. Here, those skilled in the art should know that the cover 70 and the cavity 10 should be in the closed state at this time to perform the vacuum pumping operation.

[0057] Here, those skilled in the art should understand that the second preset height can be adjusted according to the actual situation, as long as it satisfies that the first wafer 50 descends to a certain height and can be well heated by the hot plate 20. Preferably, the second preset height can enable the first wafer 50 to fully contact the hot plate 20, so as to obtain the best heating effect.

[0058] In this step, the hot plate 20 preheats the first wafer 50. The first wafer 50 and / or the second wafer 60 to be bonded have been pre-coated with bonding glue before the above-mentioned steps one to three. After preheating the first wafer 50, the generation of bubbles in the bonding glue can be reduced in the subsequent bonding process, and the bonding quality can be improved.

[0059] Step four, refer to Figure 14 , the limiting component 32 of the limiting mechanism 30 synchronously rises to the third preset height, and the third preset height is less than or equal to the first preset height; all the support cantilevers 42 rotate to the first state, that is, enter the limiting area, so that the second wafer 60 falls on the first wafer 50, and the second wafer 60 and the first wafer 50 are in a fitting state.

[0060] Subsequently, the bonding operation can be performed on the first wafer 50 and the second wafer 60.

[0061] Here, the third preset height is preferably equal to the first preset height, so that the second wafer 60 can always be located within the limiting area defined by the limiting mechanism 30 during the falling process, thereby ensuring that the centers of the first wafer 50 and the second wafer 60 can still maintain a concentric state.

[0062] Optionally, the first wafer 50 is a semiconductor wafer, for example, a silicon-based wafer, a gallium nitride wafer, etc.; the second wafer 60 is a carrier wafer, for example, glass, sapphire, silicon carbide, etc. The second wafer 60 serves as a substrate to provide support for the first wafer 50. Optionally, the first wafer 50 and the second wafer 60 can also be homogeneous wafers, that is, both the first wafer 50 and the second wafer 60 are semiconductor wafers; further, both the first wafer 50 and the second wafer 60 can be silicon-based wafers of standard thickness, or both can be thinned silicon-based wafers, or the first wafer 50 is a thinned silicon-based wafer and the second wafer 60 is a silicon-based wafer of standard thickness, etc. are specific examples.

[0063] The series of detailed descriptions listed above are only specific descriptions of the feasible implementation manners of the present application, and they are not intended to limit the protection scope of the present application. Any equivalent implementation manners or changes made without departing from the technical spirit of the present application should be included within the protection scope of the present application.

[0064] For those skilled in the art, it is obvious that the present application is not limited to the details of the above exemplary embodiments, and without departing from the spirit or basic characteristics of the present application, the present application can be implemented in other specific forms. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present application is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present application. Any reference signs in the claims should not be regarded as limiting the claims involved.

[0065] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative manner of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A wafer alignment system, characterized in that, comprising: a hot plate; a limiting mechanism, passing through the hot plate, wherein the limiting mechanism includes at least two supporting components that jointly form a limiting area to support and limit the wafer, and the supporting components move up and down in a direction perpendicular to the hot plate; an auxiliary alignment mechanism, disposed around the hot plate, wherein the auxiliary alignment mechanism includes at least two pairs of supporting cantilevers, and the supporting cantilevers rotate synchronously to enter and exit the limiting area, and the two supporting cantilevers of each pair of supporting cantilevers rotate synchronously in opposite directions to realize entering and exiting the limiting area.

2. The wafer alignment system according to claim 1, characterized in that, the limiting mechanism further includes a first driving mechanism, wherein the first driving mechanism drives the supporting components to move up and down in a direction perpendicular to the hot plate.

3. The wafer alignment system according to claim 1, characterized in that, the auxiliary alignment mechanism further includes a rotating mechanism matching the supporting cantilever, and the rotating mechanism drives the supporting cantilever to rotate.

4. The wafer alignment system according to claim 3, characterized in that, further comprising a synchronization mechanism, the synchronization mechanism connecting all the rotating mechanisms, and the synchronization mechanism synchronously driving all the rotating mechanisms, and further synchronously driving all the supporting cantilevers.

5. The wafer alignment system according to claim 4, characterized in that, the synchronization mechanism includes a synchronization connection component and a second driving mechanism, the synchronization connection component simultaneously connecting the second driving mechanism and all the rotating mechanisms, wherein the second driving mechanism makes a telescopic movement in the vertical direction, so as to synchronously drive all the rotating mechanisms through the synchronization connection component.

6. The wafer alignment system according to claim 5, characterized in that, the synchronization connection component includes a frame body and a cross bar horizontally spanning the frame body, wherein the second driving mechanism is connected to the cross bar, and all the rotating mechanisms are connected to the frame body.

7. The wafer alignment system according to claim 5, characterized in that, the rotating mechanism includes: a top block abutted against the frame body, a fixed seat slidably connected to the top block, a driving column, a moving block driven by the driving column and moving up and down in the vertical direction, a rotating shaft connecting the supporting cantilever, spiral guiding grooves symmetrically formed on the side walls of two rotating shafts on the same side of the hot plate, and guiding ends of two moving blocks on the same side of the hot plate connected to extend into the spiral guiding grooves.

8. A wafer bonding device, characterized in that, comprising: a cavity, a cover body connected to the cavity, wherein the cavity and the cover body accommodate the wafer alignment system according to any one of claims 1 to 7.

9. A wafer bonding alignment method implemented by using the wafer bonding device according to claim 8, characterized in that, comprising: raising the supporting components to a first preset height, synchronously rotating all the supporting cantilevers to rotate outside the limiting area, placing a first wafer on the supporting components, and making the first wafer located in the limiting area, wherein the supporting components support and limit the first wafer; Synchronously rotate all the support cantilevers into the limit area, place the second wafer on the support cantilevers, and make the second wafer located in the limit area, wherein the support cantilevers support the second wafer, and the support assembly positions the second wafer; Lower the support assembly to a second preset height, heat the first wafer by the hot plate, and evacuate the cavity; Raise the support assembly to a third preset height, where the third preset height is less than or equal to the first preset height, synchronously rotate all the support cantilevers out of the limit area, so that the second wafer falls on the first wafer.

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