CN119252774B - Wafer bonding device and method - Google Patents

Abstract

The invention discloses wafer bonding equipment and a wafer bonding method, wherein the equipment comprises an air bag device for pressing a wafer, the air bag device comprises a mounting frame, a floating mechanism, a fixing frame and an air bag which are sequentially arranged up and down, the air bag is arranged below the fixing frame, the fixing frame is rotationally connected with the mounting frame through the floating mechanism, the floating mechanism comprises a ball bearing and a plurality of supporting rods, two ends of the ball bearing are respectively connected with the middle part of the fixing frame and the middle part of the mounting frame, the supporting rods are respectively circumferentially distributed on the periphery of the ball bearing at intervals, the lower ends of the supporting rods are fixedly connected with the fixing frame, and the upper ends of the supporting rods are movably arranged through movable holes arranged on the mounting frame. Therefore, when the air bag presses down the wafers in the wafer bonding process, the air bag can swing freely in a certain range by means of the rotating connection of the ball bearings and the limit of each supporting rod, the effect of removing air bubbles in two wafers from the middle to the outside can be achieved, bonding tightness between the two wafers is ensured, and bonding strength and accuracy are improved.

Description

Wafer bonding equipment and method

Technical Field

The present invention relates to the field of semiconductor manufacturing technology, and more particularly to a wafer bonding apparatus and method

Background

The wafer bonding technology refers to that two wafers which are mirror polished and are homogeneous or heterogeneous are tightly combined through chemical and physical actions, and atoms of an interface react to form covalent bonds to be combined into a whole under the action of external force after the wafers are combined, so that the bonding interface reaches specific bonding strength.

The bonding technology can effectively solve the problems of lattice mismatch and flatness. This ensures that the difference between the surface flatness and the elastic modulus of the two bonded wafers is small, and that the surface required for bonding needs to be very smooth and the surface roughness needs to be very high. In the prior art, two wafers are usually placed in wafer bonding equipment, and the two bonded wafers are pressed by a pressing head to be tightly combined, the pressing head is made of graphite pressing heads, but the graphite pressing heads are harder, so that the bonding of the wafers can be influenced to a certain extent, and the pressing effect can be improved because the pressing heads are flexible pressing heads made of air bags, but the wafers are often recycled in the production process, and warping exists in the wafers, so that the defects of unsound bonding, dislocation of the two wafers, residual bubbles among the wafers and the like still exist when the conventional straight-up and straight-down air bags are used for pressing, and the bonding strength and the bonding precision are influenced.

In order to overcome the above-mentioned drawbacks, the present inventors have devised a wafer bonding apparatus and method, and have developed therefrom.

Disclosure of Invention

The present invention is directed to a wafer bonding apparatus and method, which can solve the above-mentioned drawbacks and ensure bonding compactness.

In order to achieve the above object, the solution of the present invention is:

The wafer bonding equipment comprises an air bag device for pressing a wafer, wherein the air bag device comprises a mounting frame, a floating mechanism, a fixing frame and an air bag which are sequentially arranged up and down, the air bag is arranged below the fixing frame, the fixing frame is rotationally connected with the mounting frame through the floating mechanism, the floating mechanism comprises a ball bearing and a plurality of supporting rods, two ends of the ball bearing are respectively connected with the middle part of the fixing frame and the middle part of the mounting frame, the supporting rods are respectively distributed on the periphery of the ball bearing at intervals in the circumferential direction, the lower ends of the supporting rods are connected and fixed to the fixing frame, and the upper ends of the supporting rods are movably arranged in movable holes formed in the mounting frame in a penetrating mode.

Further, the middle part of mount is equipped with the fixed slot, transversely establishes the dead lever in the fixed slot, ball bearing's bearing portion supplies the dead lever to pass and can freely rotate in the fixed slot, ball bearing's connecting rod portion is fixed with the mounting bracket connection.

The movable hole is a counter bore arranged on the upper side surface of the mounting frame and penetrates through the bottom surface of the mounting frame, the four support rods are bolts, the heads of the bolts are accommodated in the movable hole, and the rod parts of the bolts penetrate through the movable hole downwards and are locked and fixed with the fixed holes arranged on the fixing frame.

Further, an air bag mounting plate is arranged below the fixing frame, the air bag mounting plate comprises an upper supporting plate and a lower supporting plate which are arranged up and down, the upper portion of the air bag is clamped and fixed by the upper supporting plate and the lower supporting plate, the lower supporting plate is annular, and the lower portion of the inflated air bag can be inflated downwards from an annular hole of the lower supporting plate to form an arc bulge.

Further, a sensor mounting plate and a plurality of pressure sensors are arranged between the air bag mounting plate and the fixing frame, the sensor mounting plate is connected and fixed above the air bag mounting plate, the pressure sensors are distributed at intervals in the circumferential direction of the center of the fixing frame, the fixing frame and the sensor mounting plate are disc-shaped, the outer diameter of the fixing frame is smaller than that of the sensor mounting plate, the upper side of the inner end of each pressure sensor is connected with the bottom of the fixing frame, and the lower side of the outer end of each pressure sensor is connected with the top of the corresponding sensor mounting plate.

Further, an upper groove which is vertically communicated is arranged between the adjacent pressure sensors on the sensor mounting plate, and a plurality of air nozzles which extend out of the upper supporting plate and are positioned in the upper groove are arranged on the upper part of the air bag.

Further, the device also comprises a frame, a machine table, a heating device, a jacking sucker and a centering device;

The machine frame is arranged adjacent to the machine table, a vertical linear module is arranged on the machine frame, the air bag device is arranged on the vertical linear module, the air bag device is suspended above the machine table, and a pressure sensor is further arranged on the air bag device;

the wafer carrier is arranged on the machine table, the heating device is arranged on the wafer carrier, the jacking sucker is arranged in a through hole of the middle carrier of the wafer carrier in a lifting manner, the centering device is arranged on the machine table and comprises two clamping jaws which are symmetrically arranged, and the two clamping jaws can move to and fro along the radial direction of the wafer carrier to be close to or far away from the wafer carrier and are used for being in opposite abutting connection with the edge of the wafer;

The centering device further comprises a notch alignment device, each clamping jaw comprises two clamping jaw abutting parts which are arranged at intervals, the notch alignment device is arranged between the two clamping jaw abutting parts of one clamping jaw, the notch alignment device comprises a protruding part which is used for being movably embedded and stretches into a notch of a wafer, and the protruding part and the clamping jaw abutting parts on two sides are circumferentially arranged at intervals.

Furthermore, a jacking driving device and a centering driving device are arranged below the wafer carrying platform of the machine platform;

The centering driving device comprises a centering cylinder, two clamping jaw fixing seats, two clamping jaw sliding seats and two clamping jaw cylinders, wherein the centering cylinder is centered on a machine table base below the circle center of the wafer carrying table, two ends of the centering cylinder are respectively provided with a power output end which moves along the radial direction of the wafer carrying table, the power output ends are respectively connected with one clamping jaw fixing seat, and the clamping jaw fixing seats are simultaneously in sliding connection with the machine table base;

the jacking driving device comprises a jacking cylinder arranged on one side of the centering cylinder, the jacking cylinder drives the sucker support to lift up and down, one end of the sucker support is located below the wafer carrying table and above the centering cylinder, the jacking sucker is mounted, and the jacking sucker is a vacuum sucker.

Further, a detection through hole is formed in the wafer carrying platform, and a wafer detection sensor is arranged below the detection through hole.

The invention also provides a wafer bonding method, which adopts the wafer bonding equipment and comprises the following steps:

The method comprises the following steps of 1, preparing in advance, resetting an air bag device, a jacking sucker and a centering device respectively, and heating and preserving heat of a wafer carrying platform by a heating device;

step 2, feeding the wafer, lifting the lifting sucker from the middle of the wafer carrier, sequentially stacking two wafers to be bonded on the lifting sucker, keeping the notch openings of the two wafers aligned primarily and facing the protruding part of the notch opening alignment device;

The wafer centering device centers the wafer, the two clamping jaws are relatively close to the wafer carrying platform along the radial direction of the wafer carrying platform and are abutted against the edge of the wafer to align the edges of the two wafers, and meanwhile, the protruding parts of the notch alignment device are gradually embedded into the notch openings of the two wafers to be bonded along with the movement of the clamping jaws, so that the two wafers are further aligned accurately;

The method comprises the steps of (4) bonding wafers, inflating and pressurizing an airbag of an airbag device, driving the airbag device to descend by a vertical linear module, enabling the airbag to be inflated continuously to be self-adaptively leveled by a floating mechanism to be tightly attached to the upper wafer after the airbag descends and abuts against the upper wafer, feeding back bonding pressure in real time through a pressure sensor in the process of driving the airbag device to descend by the vertical linear module, stopping inflation when the bonding pressure reaches a first pressure value, and controlling clamping jaws of a centering device to reset and separate from the wafer;

And 5, blanking the bonding sheet, lifting the lifting sucker, lifting the bonding sheet formed by two wafers bonded on the wafer carrier, and taking away the bonding sheet.

After the technical scheme of the equipment is adopted, the air bag is connected to the fixed frame, and the fixed frame is connected through the floating mechanism, so that in the wafer bonding process, the air bag is inflated firstly, and the air bag is abutted against the wafer above in the inflating process, so that the air bag can be automatically leveled according to the flatness of the wafer by means of the rotating connection of the ball bearings and the limit of each supporting rod, the air bag after inflation can be integrally attached to the wafer above, the situation that the flatness of two wafers is different and the wafers are partially pressed to generate dislocation in the bonding process is prevented, the air bag is arranged, the effect of outwards removing air bubbles in the two wafers from the middle is realized, the bonding tightness between the two wafers is ensured, the air bubbles are not remained between the wafers, the bonding strength and the bonding precision are improved, and the bonding power is greatly improved.

After the technical scheme of the method is adopted, the two wafers can be automatically aligned through the centering device and adsorbed by the jacking sucker, so that the wafers are not misplaced, the air bag device is arranged, the air bag has a self-adaptive leveling function, the air bag device is provided with the pressure sensor, the pressing force is controllable, and the bonding compactness is ensured. The invention can remove bubbles in two wafers from the middle to the outside during bonding, and ensure that bubbles are not generated during bonding of the wafers. Meanwhile, the bonding force and the stroke of the wafer are controllable, the air bag device has a pressure maintaining function, the wafer leveling function is realized, stable bonding can be realized on the warped wafer, and the flatness and the bonding yield of the bonding sheet can be effectively improved. Compared with the prior art, the invention has the following advantages:

① The invention has compact integral structure and small occupied area, and can realize automation;

② The invention can perform centering and bonding on the wafer;

③ The bonding strength and the stroke of the wafer can be controlled;

④ The air bag is inflated into an arc shape, so that bubbles in two wafers can be removed from the middle to the outside during bonding, and no bubbles are generated during bonding of the wafers;

⑤ The air bag has the pressure maintaining function, realizes the wafer leveling function, and can realize stable bonding on the warped wafer.

Drawings

FIG. 1 is a perspective view of an embodiment of the present invention;

FIG. 2 is a perspective view of an airbag device of an embodiment of the invention, concealing an airbag device housing;

FIG. 3 is a perspective view of the airbag assembly of FIG. 2 with the airbag module cover removed;

FIG. 4 is a perspective view of the mounting bracket of FIG. 3 with the mounting bracket removed;

FIG. 5 is a perspective view of an airbag and airbag mounting plate of an airbag assembly of an embodiment of the present invention;

FIG. 6 is a perspective view of a portion of the structure of an embodiment of the present invention;

FIG. 7 is a perspective view of the machine housing of FIG. 6 removed;

FIG. 8 is a perspective view of a lift cup and lift drive of an embodiment of the present invention;

FIG. 9 is a perspective view of a centering device and centering drive device according to an embodiment of the present invention;

FIG. 10 is a flow chart of a method according to an embodiment of the present invention;

fig. 11 is another angular perspective view of an embodiment of the present invention.

Reference numerals illustrate the wafer 1;

Airbag device 100, mounting bracket 110, movable hole 111, floating mechanism 120, ball bearing 121, strut 122, bearing portion 123, link portion 124, mount 130, fixing groove 131, fixing rod 132, fixing hole 133, airbag 140, air tap 141, airbag device cover 150, airbag device housing 160, airbag mounting plate 170, upper support plate 171, lower support plate 172, sensor mounting plate 180, pressure sensor 181, inner upper side 182, outer lower side 183, upper groove 184;

a frame 200;

A machine 300, a wafer carrier 310, a carrier through hole 311, a detection through hole 312, a wafer detection sensor 313, a detection light 314, a machine housing 320, a machine base 330, and a base bracket 331;

lifting the sucker 400;

centering device 500, jaw 510, jaw abutment 511, notch alignment device 520, projection 521;

A jacking driving device 600, a jacking cylinder 610 and a sucker support 620;

Centering driving device 700, centering cylinder 710, power output end 711, clamping jaw fixing seat 720, clamping jaw sliding seat 730, clamping jaw cylinder 740;

a vertical straight line module 800;

Control device 900, display assembly 910.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present application more apparent, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments of the present application. The components of the embodiments of the present application generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

As shown in fig. 1 to 9, a wafer bonding apparatus of the present embodiment includes an airbag device 100 for pressing a wafer 1, and a frame 200, a stage 300, a heating device (not shown), a lift suction cup 400, a centering device 500, a lift driving device 600, a centering driving device 700, a vertical linear module 800, and a control device 900.

Referring to fig. 2 to 5, the airbag device 100 includes a mounting frame 110, a floating mechanism 120, a fixing frame 130 and an airbag 140 sequentially arranged up and down, the airbag 140 is installed below the fixing frame 130, the fixing frame 130 is rotationally connected with the mounting frame 110 through the floating mechanism 120, the floating mechanism 120 includes a ball bearing 121 and a plurality of struts 122, two ends of the ball bearing 121 are respectively connected with the middle of the fixing frame 130 and the middle of the mounting frame 110, the struts 122 are respectively circumferentially and alternately distributed on the periphery of the ball bearing 121, the lower ends of the struts 122 are fixedly connected with the fixing frame 130, and the upper ends of the struts 122 movably penetrate through movable holes 111 arranged on the mounting frame 110.

Therefore, the air bag 140 of the embodiment is connected to the fixing frame 130, and the fixing frame 130 is connected through the floating mechanism 120, so that when the air bag 140 presses down the wafer 1 in the wafer bonding process, the air bag 140 can swing freely within a certain range by means of the rotating connection of the ball bearing 121 and the limit of each supporting rod 122, the self-adaptive leveling function can be realized, the effect of removing air bubbles in the two wafers 1 from the middle to the outside can be realized, the bonding between the two wafers 1 is ensured to be tight, no air bubbles remain between the wafers, the bonding strength and the bonding precision are improved, and the bonding power is greatly improved.

More specifically, since the flatness of the two wafers 1 cannot be completely consistent, there may be a situation that one side of the two wafers 1 is uneven when stacked, and the airbag 140 of the airbag device 100 may initially press against the wafer 1 above after pre-inflation, and since the ball bearing 121 is provided, the airbag 140 may perform adaptive rotation leveling according to the flatness of the wafer 1 during the subsequent continuous inflation, so that the airbag 140 integrally presses the wafer 1 after the inflation is completed, thereby ensuring that the wafer 1 is integrally stressed when being pressed, and the upper wafer 1 will not be locally stressed to generate dislocation with the lower wafer 1, thereby realizing an adaptive leveling function and ensuring that the flatness of the two wafers 1 is high.

Specifically, as shown in fig. 1 and 2, the outer peripheries of the mounting frame 110, the floating mechanism 120, and the fixing frame 130 may be surrounded by an airbag device top cover 150 and an airbag device cover 160 to protect the internal structure.

As shown in fig. 4, a fixing groove 131 may be formed in the middle of the fixing frame 130, a fixing rod 132 is transversely disposed in the fixing groove 131, two ends of the fixing rod 132 may be locked and fixed on two sides of the fixing groove 131, the bearing portion 123 of the ball bearing 121 may allow the fixing rod 132 to pass through and rotate freely in the fixing groove 131, and the connecting rod portion 124 of the ball bearing 121 is connected and fixed with the mounting frame 110. Thus, the airbag 140, the fixing frame 130 and the fixing rod 132 can freely rotate in cooperation with the bearing portion 123, and also facilitate assembly operations.

Referring to fig. 3, the movable hole 111 may be a counter bore disposed on the upper side of the mounting frame 110 and penetrating through the bottom of the mounting frame 110, and the supporting rods 122 may have four bolts, the heads of the bolts are accommodated in the movable hole 111, and the rod portions of the bolts pass through the movable hole 111 downwards and then are locked and fixed with the fixing holes 133 disposed on the fixing frame 130. Accordingly, after the ball bearing 121 rotatably connects the fixing frame 130 and the mounting frame 110, each bolt can be quickly mounted, and the head of the bolt can swing movably in the movable hole 111, so that each strut 122 formed by the bolts can limit the swing amplitude of the air bag 140 and the fixing frame 130, but cannot swing, and the pressing effect of the air bag 140 can be ensured.

As shown in fig. 4 and 5, an air bag mounting plate 170 may be disposed below the fixing frame 130, where the air bag mounting plate 170 includes an upper support plate 171 and a lower support plate 172 that are disposed up and down, the upper portion of the air bag 140 is clamped and fixed by the upper support plate 171 and the lower support plate 172, the lower support plate 172 is annular, and the inflated lower portion of the air bag 140 can expand downward from the annular hole of the lower support plate 172 to form an arc bulge.

A sensor mounting plate 180 and a plurality of pressure sensors 181 may be further disposed between the airbag mounting plate 170 and the fixing frame 130.

The sensor mounting plate 180 is connected and fixed above the airbag mounting plate 170, the pressure sensors 181 are distributed at intervals in the circumferential direction of the center of the fixing frame 130, the fixing frame 130 and the sensor mounting plate 180 are disc-shaped, the outer diameter of the fixing frame 130 is smaller than that of the sensor mounting plate 180, the upper side 182 of the inner end of the pressure sensor 181 is connected with the bottom of the fixing frame 130, and the lower side 183 of the outer end of the pressure sensor 181 is connected with the top of the sensor mounting plate 180.

The pressure sensors 181 are arranged to detect the pressure of the air bag 140 in the process of pressing and bonding the wafer 1 in real time so as to realize good bonding effect.

In order to facilitate inflation and deflation of the air bag 140, the sensor mounting plate 180 of the present embodiment is provided with an upper slot 184 penetrating up and down between adjacent pressure sensors 181, and the upper portion of the air bag 140 is provided with a plurality of air nozzles 141 extending out of the upper support plate 171 and located in the upper slot 184. Each air tap 141 may be connected to an external device (not shown) for inflating or deflating the air bag 140.

As shown in fig. 1 and 6 to 9, the frame 200 and the table 300 of the present embodiment are disposed adjacent to each other.

The frame 200 is provided with a vertical linear module 800 and a control device 900, the vertical linear module 800 is provided with the airbag device 100, the airbag device 100 is suspended above the machine 300, the vertical linear module 800 is used for controlling the airbag device 100 to move up and down to press the wafer 1, the control device 900 is used for controlling the operation of the airbag device 100, the vertical linear module 800, the heating device, the jacking sucker 400, the centering device 500 and the like, the control device 900 is also provided with a display assembly 910, and the pressure value of the pressure sensor 181 and the like can be displayed (see fig. 11).

The machine 300 is provided with a wafer carrier 310, a lift-up chuck 400, a centering device 500, a lift-up driving device 600 and a centering driving device 700.

The wafer carrier 310 is located on the top surface of the machine 300 and is provided with the heating device, the heating device can be used for heating and preserving heat of the wafer carrier 310 and the wafer 1 thereon by adopting the prior art, the jacking sucker 400 is located in the middle carrier through hole 311 of the wafer carrier 310 in a lifting manner, the centering device 500 is mounted on the machine 300 and comprises two clamping jaws 510 which are symmetrically arranged, the two clamping jaws 510 can move to and fro along the radial direction of the wafer carrier 310 to approach or separate from the wafer carrier 310 for abutting against the edge of the wafer 1 oppositely, and the wafer 1 placed on the wafer carrier 310 is aligned and positioned.

The machine 300 may further be provided with a machine housing 320 and a machine base 330, the wafer carrier 310 is exposed on the top surface of the machine 300, the two clamping jaws 510 of the centering device 500 are movably disposed on two sides of the top surface of the machine 300, and the machine housing 320 and the machine base 330 are used for protecting the internal structure of the machine 300.

The centering device 500 further comprises a notch alignment device 520, each clamping jaw 510 comprises two clamping jaw abutting parts 511 which are arranged at intervals, the notch alignment device 520 is arranged between the two clamping jaw abutting parts 511 of one clamping jaw 510, the notch alignment device 520 comprises a protruding part 521 which is used for being movably embedded and protruding into a notch (not shown) of the wafer 1, and the protruding part 521 and the clamping jaw abutting parts 511 at two sides are arranged at intervals in the circumferential direction.

Therefore, when the two clamping jaws 510 relatively move close to clamp and align the edges of the wafers 1, the protruding portion 521 can move synchronously along with the clamping jaws 510 and gradually is embedded into the notch of the two wafers 1, and the two wafers 1 are aligned at the same time in the embedding process, that is, the two wafers 1 can be precisely aligned at one time, so that the uniformity of the two wafers 1 during feeding is effectively ensured.

Specifically, as shown in fig. 7 to 9, the lift driving device 600 and the centering driving device 700 are installed below the wafer stage 310 of the machine 300.

As shown in fig. 7 and 9, the centering driving device 700 includes a centering cylinder 710, two clamping jaw fixing seats 720, two clamping jaw sliding seats 730 and two clamping jaw cylinders 740, wherein the centering cylinder 710 is centrally located on a base bracket 331 of the machine base 330 below the center of the wafer carrier 310, two ends of the centering cylinder 710 are respectively provided with a power output end 711 moving along the radial direction of the wafer carrier 310, the power output ends 711 are respectively connected with one clamping jaw fixing seat 720, the clamping jaw fixing seats 720 are simultaneously slidingly connected to a base bracket 331 arranged on the machine base 330, and therefore, the power output ends 711 at two ends of the centering cylinder 710 can simultaneously extend or retract to drive the two clamping jaw fixing seats 720 to be relatively far away from or close to each other.

The clamping jaw sliding seat 730 is slidingly connected to the clamping jaw fixing seat 720, the clamping jaw cylinder 740 is mounted on the clamping jaw fixing seat 720, the clamping jaw cylinder 740 drives the clamping jaw sliding seat 730 to slide back and forth on the clamping jaw fixing seat 720, the clamping jaw 510 is mounted on the clamping jaw sliding seat 730, therefore, the centering cylinder 710 drives the clamping jaw fixing seat 720 to move away from or close to each other, namely, the two clamping jaw sliding seats 730 and the clamping jaw 510 thereon can be driven by the clamping jaw cylinder 740 to move away from or close to clamp and align the wafer 1, and the clamping jaw 510 can be driven by the clamping jaw cylinder 740 to slide on the clamping jaw sliding seat 730, so that the distance between the two clamping jaws 510 can be adjusted to be suitable for wafers 1 with different sizes, and the adaptability of the device is improved.

As shown in fig. 7 and 8, the lifting driving device 600 includes a lifting cylinder 610 disposed at one side of the centering cylinder 710, the lifting cylinder 610 drives a chuck support 620 to lift up and down, one end of the chuck support 620 is located below the wafer carrier 310 and above the centering cylinder 710, and the lifting chuck 400 is mounted, and the lifting chuck 400 may be a vacuum chuck, so that the vacuum adsorption fixing of the wafer 1 may be realized. Thus, the lift cylinder 610 drives the chuck support 620 to lift, so as to drive the lift chuck 400 to move up and down in the middle stage through hole 311 of the wafer stage 310.

In this embodiment, the wafer carrier 310 is further provided with a detection through hole 312, and a wafer detection sensor 313 is disposed below the detection through hole 312, and a detection light 314 of the wafer detection sensor 313 is generally shown in the figure, for detecting whether the wafer 1 is placed on the wafer carrier 310.

As shown in fig. 10, the present invention further provides a wafer bonding method, which mainly adopts the above-mentioned wafer bonding apparatus, and can implement effective bonding of the wafer 1, and improve bonding strength and accuracy, and the wafer bonding method includes the following steps:

The method comprises the following steps of 1, preparing in advance, resetting an air bag device 100, a jacking sucker 400 and a centering device 500, and heating and preserving heat of a wafer carrier 310 by a heating device;

Step 2, feeding the wafer 1, lifting the jacking sucker 400 from the middle of the wafer carrier 310, sequentially stacking two wafers 1 to be bonded on the jacking sucker 400, keeping the notch openings of the two wafers 1 aligned preliminarily and facing the convex part 521 of the notch opening alignment device 520 at the same time, controlling the jacking sucker 400 to adsorb the wafer 1, driving the wafer 1 to descend to the wafer carrier 310, and cutting off the adsorption of the jacking sucker 400 to enable the wafer 1 to be horizontally placed on the wafer carrier 310;

Step 3, centering the wafer 1 by the centering device 500, wherein the two clamping jaws 510 are relatively close to the wafer carrier 310 along the radial direction of the wafer carrier 310 and are abutted against the edge of the wafer 1 to align the edges of the two wafers 1, and meanwhile, the protruding parts 521 of the notch alignment device 520 are gradually embedded into the notch openings of the two wafers 1 to be bonded along with the movement of the clamping jaws 510, so that the two wafers 1 are further aligned accurately;

Step 4, bonding wafers, inflating and pressurizing the air bag 140 of the air bag device 100, driving the air bag device 100 to descend by the vertical linear module 800, enabling the continuously inflated air bag 140 to be self-adaptively leveled and tightly attached to the upper wafer 1 by utilizing the floating mechanism 120 after the air bag 140 descends and abuts against the upper wafer 1, feeding back bonding pressure in real time by the pressure sensor 181 in the process that the air bag device 100 is driven by the vertical linear module 800 to descend, stopping inflating when the bonding pressure reaches a first pressure value, controlling the clamping jaw 510 of the centering device 500 to reset and separate from the wafer 1, continuously driving the air bag device 100 to descend, further pressurizing the two wafers 1 by the vertical linear module 800, controlling the vertical linear module 800 to stop maintaining pressure when the bonding pressure reaches a second pressure value, maintaining the pressure for a first time period, resetting the air bag device 100 after the maintaining is completed, and exhausting the air bag 140;

And 5, blanking the bonding sheets, lifting the lifting sucker 400, lifting the bonding sheets formed by two bonded wafers 1 on the wafer carrier 310, and taking the bonding sheets away.

The values of the first pressure value, the second pressure value and the first time period can be selected and set according to actual production requirements. For example, the first pressure value may be 1500 g.+ -. 100g, the second pressure value may be 2000 g.+ -. 100g, and the first time period may be 2 seconds in value.

Therefore, the alignment device 500 can automatically align two wafers 1, the jacking sucker 400 is utilized to adsorb the wafers 1, the wafer 1 is prevented from dislocation, the air bag device 100 is further arranged, the air bag 140 has the self-adaptive leveling function, the air bag device 100 is provided with the pressure sensor 181, the pressing force is controllable, and the bonding compactness is ensured.

The invention can remove bubbles in the two wafers 1 from the middle to the outside during bonding, and ensure that bubbles are not generated during bonding of the wafers. Meanwhile, the bonding force and the stroke of the wafer are controllable, the air bag device 100 has a pressure maintaining function, the leveling function of the wafer 1 is realized, stable bonding can be realized on the warped wafer 1, and the flatness and the bonding yield of the bonding sheet can be effectively improved.

After the scheme is adopted, compared with the prior art, the invention has the following advantages:

① The invention has compact integral structure and small occupied area, and can realize automation;

② The invention can perform centering and bonding on the wafer 1;

③ The bonding strength and the stroke of the wafer can be controlled;

④ The air bag 140 is inflated into an arc shape, so that bubbles in the two wafers 1 can be removed from the middle to the outside during bonding, and no bubbles are generated during bonding of the wafers;

⑤ The air bag 140 has a pressure maintaining function, realizes a leveling function of the wafer 1, and can realize stable bonding of the warped wafer 1.

The above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above examples, and all technical solutions belonging to the concept of the present invention belong to the protection scope of the present invention. It should be noted that equivalent changes and modifications can be made by those skilled in the art without departing from the principles of the present invention, which still falls within the scope of the present invention.

In the description of the embodiments of the present application, it should be understood that the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship conventionally put in place when the application product is used, or the orientation or positional relationship conventionally understood by those skilled in the art is merely for convenience of describing the present application and simplifying the description, and is not indicative or implying that the apparatus or element in question must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present application.

Claims (8)

1. The wafer bonding equipment is characterized by comprising an air bag device for pressing a wafer, wherein the air bag device comprises a mounting frame, a floating mechanism, a fixing frame and an air bag which are sequentially arranged up and down, the air bag is arranged below the fixing frame, the fixing frame is rotationally connected with the mounting frame through the floating mechanism, the floating mechanism comprises a ball bearing and four supporting rods, two ends of the ball bearing are respectively connected with the middle part of the fixing frame and the middle part of the mounting frame, the supporting rods are respectively circumferentially and alternately distributed on the periphery of the ball bearing, the lower ends of the supporting rods are fixedly connected with the fixing frame, and the upper ends of the supporting rods are movably arranged in movable holes formed in the mounting frame in a penetrating mode;

The lower support plate is annular, and the lower part of the inflated air bag can be expanded downwards from the annular hole of the lower support plate to form an arc bulge;

A sensor mounting plate and a plurality of pressure sensors are arranged between the air bag mounting plate and the fixing frame; the sensor mounting plate is connected and fixed above the air bag mounting plate, the pressure sensors are distributed at intervals in the circumferential direction of the center of the fixing frame, the fixing frame and the sensor mounting plate are disc-shaped, the outer diameter of the fixing frame is smaller than that of the sensor mounting plate, the upper side of the inner end of each pressure sensor is connected with the bottom of the fixing frame, and the lower side of the outer end of each pressure sensor is connected with the top of the corresponding sensor mounting plate.

2. The wafer bonding apparatus according to claim 1, wherein a fixing groove is formed in the middle of the fixing frame, a fixing rod is transversely arranged in the fixing groove, the fixing rod penetrates through a bearing portion of the ball bearing and can freely rotate in the fixing groove, and a connecting rod portion of the ball bearing is fixedly connected with the mounting frame.

3. The wafer bonding equipment according to claim 1, wherein the movable hole is a counter bore arranged on the upper side surface of the mounting frame and penetrates through the bottom surface of the mounting frame, the supporting rods are bolts, the heads of the bolts are accommodated in the movable hole, and the rod parts of the bolts penetrate through the movable hole downwards and are locked and fixed with the fixing holes arranged on the fixing frame.

4. The wafer bonding apparatus according to claim 1, wherein the sensor mounting plate is provided with an upper groove penetrating up and down between the adjacent pressure sensors, and the upper part of the air bag is provided with a plurality of air nozzles extending out of the upper support plate and positioned in the upper groove.

5. The wafer bonding apparatus of claim 1, further comprising a frame, a table, a heating device, a lift-up chuck, and a centering device;

The machine frame is arranged adjacent to the machine table, a vertical linear module is arranged on the machine frame, the air bag device is arranged on the vertical linear module, the air bag device is suspended above the machine table, and a pressure sensor is further arranged on the air bag device;

the wafer carrier is arranged on the machine table, the heating device is arranged on the wafer carrier, the jacking sucker is arranged in a through hole of the middle carrier of the wafer carrier in a lifting manner, the centering device is arranged on the machine table and comprises two clamping jaws which are symmetrically arranged, and the two clamping jaws can move to and fro along the radial direction of the wafer carrier to be close to or far away from the wafer carrier and are used for being in opposite abutting connection with the edge of the wafer;

The centering device further comprises a notch alignment device, each clamping jaw comprises two clamping jaw abutting parts which are arranged at intervals, the notch alignment device is arranged between the two clamping jaw abutting parts of one clamping jaw, the notch alignment device comprises a protruding part which is used for being movably embedded and stretches into a notch of a wafer, and the protruding part and the clamping jaw abutting parts on two sides are circumferentially arranged at intervals.

6. The wafer bonding apparatus according to claim 5, wherein a lifting driving device and a centering driving device are installed below the wafer carrier of the machine;

The centering driving device comprises a centering cylinder, two clamping jaw fixing seats, two clamping jaw sliding seats and two clamping jaw cylinders, wherein the centering cylinder is centered on a machine table base below the circle center of the wafer carrying table, two ends of the centering cylinder are respectively provided with a power output end which moves along the radial direction of the wafer carrying table, the power output ends are respectively connected with one clamping jaw fixing seat, and the clamping jaw fixing seats are simultaneously in sliding connection with the machine table base;

the jacking driving device comprises a jacking cylinder arranged on one side of the centering cylinder, the jacking cylinder drives the sucker support to lift up and down, one end of the sucker support is located below the wafer carrying table and above the centering cylinder, the jacking sucker is mounted, and the jacking sucker is a vacuum sucker.

7. The wafer bonding apparatus according to claim 5, wherein the wafer stage has a detection via, and a wafer detection sensor is disposed below the detection via.

8. A wafer bonding method using a wafer bonding apparatus according to any one of claims 5 to 7, comprising the steps of:

The method comprises the following steps of 1, preparing in advance, resetting an air bag device, a jacking sucker and a centering device respectively, and heating and preserving heat of a wafer carrying platform by a heating device;

step 2, feeding the wafer, lifting the lifting sucker from the middle of the wafer carrier, sequentially stacking two wafers to be bonded on the lifting sucker, keeping the notch openings of the two wafers aligned primarily and facing the protruding part of the notch opening alignment device;

The wafer centering device centers the wafer, the two clamping jaws are relatively close to the wafer carrying platform along the radial direction of the wafer carrying platform and are abutted against the edge of the wafer to align the edges of the two wafers, and meanwhile, the protruding parts of the notch alignment device are gradually embedded into the notch openings of the two wafers to be bonded along with the movement of the clamping jaws, so that the two wafers are further aligned accurately;

The method comprises the steps of (4) bonding wafers, inflating and pressurizing an airbag of an airbag device, driving the airbag device to descend by a vertical linear module, enabling the airbag to be inflated continuously to be self-adaptively leveled by a floating mechanism to be tightly attached to the upper wafer after the airbag descends and abuts against the upper wafer, feeding back bonding pressure in real time through a pressure sensor in the process of driving the airbag device to descend by the vertical linear module, stopping inflation when the bonding pressure reaches a first pressure value, and controlling clamping jaws of a centering device to reset and separate from the wafer;

And 5, blanking the bonding sheet, lifting the lifting sucker, lifting the bonding sheet formed by two wafers bonded on the wafer carrier, and taking away the bonding sheet.