JPS6119110B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a wafer bonding device that can bond a crystal substrate to an adhesive plate with high precision.

In recent years, integrated circuits using silicon substrates and GGG
Magnetic bubble circuits using (gadolinium gallium garnet) substrates are progressing in the direction of further miniaturization and higher density. For this reason, there is a need for processing techniques that efficiently produce crystal substrates with high flatness. When processing this crystal substrate, a method is used in which the crystal substrate is bonded to an adhesive plate, but in order to process the crystal substrate to a high degree of flatness, it is necessary to make the thickness of the adhesive layer thin and uniform. Therefore, the present inventors have already proposed in Japanese Patent Application No. 51-75587 (Japanese Unexamined Patent Publication No. 53-1464) ``Method for bonding crystal substrates'' that a solution of adhesive wax dissolved in an organic solvent was applied to the wafer surface and the bonding plate. Alternatively, an adhesion method was proposed in which the wafer is applied in a spray form to either one of them, and then the wafer is placed on an adhesive plate and bonded by heating and pressing.

However, even with this bonding method, the wafers are handled manually, so there are many opportunities for the wafers to become contaminated or for dust to enter the adhesive layer, resulting in problems with bonding reproducibility, work efficiency, etc. It also required the skill of the operator. Furthermore, in bonding crystal substrates, it is an important issue to align the orientation flats (notches) of the wafer in a predetermined direction.

The present invention has been made in view of the above-mentioned points, and eliminates the causes of defects caused by operator errors by automatically performing a series of processes: spraying adhesive, drying and evaporating solvent, and positioning and adhering. It is an object of the present invention to provide a wafer bonding device that can improve work efficiency, reduce dust intrusion into the adhesive layer, and bond with high precision.

To achieve this objective, the wafer bonding apparatus of the present invention suction-holds the wafer supplied to the chucking station with a wafer suction plate, transfers it to a spray chamber, and rotates the wafer suction plate in the spray chamber. The adhesive is sprayed onto one side of the wafer, the solvent in the adhesive is dried and evaporated in a drying chamber, the wafer is rotated and stopped at a predetermined position, and then the wafer is placed on an adhesive plate on an indexing plate. The wafer is bonded by pressing the wafer with the wafer suction plate.

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

FIG. 1 is a partially cutaway overall perspective view showing an embodiment of a wafer bonding apparatus according to the present invention, and FIG. 2 is a cross-sectional view of a suction mechanism. In these figures, the wafer bonding apparatus, generally designated by the reference numeral 1, includes a wafer carrier 2, and a plurality of wafers 3 are housed in a stacked state inside the wafer carrier 2. A chucking station 4 is disposed on the right side of this wafer carrier 2, a wafer supply mechanism A is disposed on the left side, and an elevator mechanism B is disposed below.

The wafer supply mechanism A is the wafer carrier 2.
The device is for pushing out the wafers 3 one by one and supplying them to the chucking station 4. For example, one end is fixed to a plate 6 that is slidably held on a shaft 5, and the other end is connected to the wafer carrier 2. a belt 9 stretched across a plurality of pulleys 8 and fixed at both ends to the plate 6;
and a drive motor (not shown) that rotates in forward and reverse directions and rotates one of the pulleys 8. Therefore, when the belt 9 is driven in the direction of the arrow by the drive motor, the plate 6
moves to the right, the pusher plate 7 penetrates the wafer carrier 2 and removes the lowermost layer of wafers 3 loaded.
By pushing forward only one wafer, wafer 3
is supplied to the chucking station 4. Then, when the feeding operation of wafer 3 is completed,
The direction of rotation of the drive motor is automatically switched to move the pusher plate 7 out of the wafer carrier 2. In addition,
Of course, the wafer supply mechanism A is not limited to this, and any conventionally known appropriate supply mechanism may be used.

The elevator mechanism B is for adjusting the height of the wafer carrier 2, and includes, for example, a drive motor 10 that can freely rotate in forward and reverse directions, a screw shaft 11 provided on the drive shaft of the drive motor 10, and this screw shaft 11. A nut 12 is screwed onto the
The wafer carrier 2 is constructed of a carrier table 14 fixed via a carrier plate 3, and the wafer carrier 2 is disposed on the carrier table 14. When the nut 12 moves up and down as the drive motor 10 rotates,
The wafer carrier 2 is raised or lowered together with the carrier table 14 to adjust its height.

Wafer 3 on the chucking station 4
is adsorbed and held by an adsorption mechanism C, and by moving this adsorption mechanism C to the right by a transfer mechanism D, it is transferred to a sprayer and a drying chamber, which will be described later. The transfer mechanism D includes a drive motor 15 that can freely rotate in forward and reverse directions, a sprocket 16a fixed to the shaft of the drive motor 15, and a sprocket 4 that is rotatably supported.
sprockets 16b to 16e, a chain 18 stretched over these sprockets 16a to 16e and fixed at both ends to the carriage 17, and a plurality of rollers 19 provided on the carriage 17.
and a pair of upper and lower rails 20 on which these rollers 19 roll. The base end of an arm 21 bent into a substantially L-shape is fixed to the upper end of the carriage 17, and an air cylinder 22 constituting the suction mechanism C is disposed at the tip of the arm 21. has been done.

As shown in FIG. 2, the suction mechanism C includes a rotating plate 26 rotatably supported via an O-ring 25 on a hollow shaft 24 having a flange 24a at the upper end.
, a suction plate 28 fixed to the center of the lower surface of the rotary plate 26 and having a small hole 27 bored in the center, and the shaft 24
a cylindrical case 30 in which the shaft 24 is housed, and the lower end of the shaft 24 projects outward from a hole 29 bored in the center of the lower surface; a nut 31 screwed into the upper end opening of the case 30; A compression spring 32 is housed in the case 30 and always urges the shaft 24 downward, and a lower end threaded portion 34a is screwed into a threaded hole 33 formed in the center of the nut 31, and the air cylinder 22 The inside of the case 30 and the small hole 27 of the suction plate 28 are communicated through the center hole 35 of the shaft 24. Further, one end of an exhaust tube 36 is connected to the circumferential surface of the case 30, and the other end of the exhaust tube 36 is connected to an exhaust pump (not shown). moreover,
The suction mechanism C is provided with a rotation stop mechanism E for rotating the rotating plate 26, in other words, the suction plate 28 as necessary, and stopping it at a predetermined position relative to the case 30. There is. This rotation stop mechanism E rotates a rotary plate 26 by the repulsion and attraction force of magnetic force, similar to a synchronous motor, and includes a plurality of permanent magnets 37 arranged concentrically on the upper surface of the rotary plate 26, and The electromagnet 40 is fixed to the outer peripheral surface of the case 30 and is formed by winding a coil 39 around an iron core 38 bent into a substantially L-shape so that the tip end face closely faces the permanent magnet 37.

In addition, a plurality of windmills 41 are disposed circumferentially around the lower surface of the rotary plate 26 .

A spray chamber 42 is disposed to the right of the chucking station 4. This spray chamber 42 is formed by a box body 42A.
A round hole into which the suction mechanism C can be inserted is formed on the upper surface of 2A to constitute an upper entrance 43. Further, a large number of nozzles 44 are formed at the upper inlet 43, and nitrogen gas is injected from the nozzles 44 to form an air curtain 45. A sprayer 46 for spraying adhesive is fixed to a plate 49 and arranged below the box body 42A. The plate 49 is housed in the box body 42A with its upper end open, and its lower end is opened in the box body 42A.
It is attached to a box-shaped mounting tube 48 projecting downward by a plurality of bolts 50 and nuts 51. Therefore, by loosening the nut 51 and moving the plate 49 up and down, the height of the atomizer 46 can be adjusted. Further, by loosening some of the nuts 51 and tilting the plate 49 in the left-right or front-back direction, the direction of the nozzle 47 of the sprayer 46 can be changed. An exhaust pipe 53 having an exhaust port 52 is installed in the lower part of the inside of the box body 42A, and this exhaust pipe 53 exhausts the adhesive injected into the spray chamber 42 and the gas in the air curtain 45 to the outside. I try to do that.

The sprayer 46 is supplied with an adhesive liquid from an adhesive container 54 through a tube 55, and is also supplied with atomizing nitrogen gas through a pipe 56 during spraying.

A box 58 forming a drying chamber 57 is disposed to the right of the spray chamber 42. The box 58 is open at the top and an infrared lamp 59 is housed inside. An index plate 60 is disposed on the right side of the box body 58 and placed on a base 61. A cushion material 62 is provided on the upper surface of the index plate 60.
An adhesive plate 63 is fixed with adhesive tape or the like via the. The cushion material 62 is attached to the wafer 3 during bonding.
This is to prevent damage caused by collision with the hard adhesive plate 63, and foamed polyurethane or the like is used. The indexing plate 60 is indexed by rotating a motor 65 fixed downwardly on the base 61 for an energizing time set by a timer (not shown), and decelerating this rotation with, for example, a worm gear. 6
This is done by telling 0.

Next, the wafer bonding operation in the above configuration will be explained.

First, a plurality of wafers 3 are loaded onto the wafer carrier 2, and the wafer carrier 2 is mounted and fixed on the carrier table 14. At this time, the wafers 3 are stacked one on top of the other with their notches 3a formed on their peripheries partially aligned, and then accommodated in the wafer carrier 2.

When the loading of the wafer 3 is completed and the wafer bonding device 1 is operated by operating a button, the bonding operation of the wafer 3 is started. That is, drive motor 1
0 to raise the wafer carrier 2,
The height of the lowest layer wafer 3 is made to match the height of the extrusion plate 7. The suction mechanism C is positioned above the chucking station 4, and the electromagnet 40 is energized to rotate the rotating plate 26, and when the suction plate 28 reaches a predetermined orientation, it is stopped.

The extrusion plate 7 is moved back and forth once to transfer only one wafer 3 in the wafer carrier 2 to the chucking station 4.
Extrude to. When extrusion of this wafer 3 is completed,
The wafer carrier 2 descends one step and prepares for the next extrusion operation. The wafer 3 on the chucking station 4 is sucked and held by the suction plate 28 as the rotary plate 26 is lowered by the drive of the air cylinder 22, and is lifted as the rotary plate 26 rises. Next, the suction mechanism C is moved onto the box body 42A by the drive of the transfer mechanism D, and inserted into the interior of the box body 42A, that is, into the spray chamber 42 from the upper entrance 43.
After injecting nitrogen gas through the nozzle 44 and setting an air curtain 45 at the upper inlet 43, atomizing nitrogen gas and adhesive liquid are sprayed from the nozzle 47 of the sprayer 46 for the time set by the spray timer, and onto the suction plate 28. Adhesive is applied to the lower surface of the wafer 3 that is being sucked. At this time, the rotating plate 26 is rotated by energizing the electromagnet 40. Therefore, the wind turbine 41 also has the rotating plate 2.
6 to make the thickness of the adhesive layer applied to the wafer 3 uniform. When the spray application of the adhesive to the wafer 3 is completed, the air curtain 45 is cut and the air cylinder 22 is driven to remove the rotary plate 26.
is raised and pulled out from the spray chamber 42. Spray chamber 42
The rotary plate 26 extracted from the rotary plate 26 is further moved to the right by the drive of the transfer mechanism D, positioned on the box body 58, and then inserted into the drying chamber 57. In conjunction with this insertion, the infrared lamp 59 is turned on, and the heat generated at this time dries and evaporates the solvent in the adhesive applied to the wafer 3 held by the suction plate 28. When the drying and evaporation of the solvent is completed, the rotary plate 26 rises again and is pulled out from the drying chamber 57, and the adhesive plate 6
Moved above 3. At this time, the rotating plate 26 is rotated by energizing the electromagnet 40, and the suction plate 28 is held still in a predetermined direction. The adhesive plate 63 is rotated together with the indexing plate 60 by the time set by the timer by the driving of the drive motor 65, thereby indexing the adhesive plate 63 relative to the wafer 3. Then,
The suction mechanism C descends and presses the wafer 3, which is suctioned and held on the suction plate 28, against the adhesive plate 63 to adhesively fix it. At this time, the compression spring 32 housed in the case 30 absorbs and relieves the impact when the wafer 3 is pressed against the adhesive plate 63, and the elastic force of the spring 32 is applied to the suction plate 28 via the shaft 24. By doing so, the wafer 3 is attached to the adhesive plate 6 by the adhesive force of the adhesive.
3. Avoid this as it will cause misalignment.

When the adhesion to the adhesive plate 63 is completed, the suction plate 28
The vacuum suction of the wafer 3 is turned off, the suction plate 28 is raised, and the suction mechanism C is returned to its original position, that is, above the chucking station 4, by driving the transfer mechanism D.

By repeating the above operations, three wafers 3 are bonded to one bonding plate 63, for example. That is, as shown in FIG. 3a, one wafer 3 is bonded onto the adhesive plate 63 in the first time, and in the second time, as shown in FIG.
3 is rotated 120 degrees and the second wafer 3 is bonded.Furthermore, for the third time, as shown in FIG.
is glued.

In addition, when mounting wafers 3 with different diameters on the adhesive plate 63 in this apparatus, the wafer carrier 2, carrier table 14, and chucking station 4 must be replaced with suitable ones, and the extrusion plate 7 must be replaced.
This is possible by changing the circuit of a limit switch (not shown) that defines the horizontal movement range of the carriage 17 and the movement range of the carriage 17 to a suitable one.

In addition, in order to achieve more complete adhesion after the series of adhesion steps described above, the wafer 3 bonded with this device
The adhesive plate 63 is heated by a heating/pressure holding device to a temperature higher than the temperature at which the adhesive melts and flows, and the wafer 3
is held under pressure by the adhesive plate 63. This makes it possible to make the adhesive layer thinner, more uniform, and strengthen the adhesive force.

As explained above, the wafer bonding apparatus according to the present invention automates the bonding process and eliminates any manual handling of wafers, making it possible to prevent handling errors and dust adhesion, and to mount wafers with high precision. can. Therefore, the adhesive layer covers the crystal substrate with a diameter of about 100 mm and is free from dust.
The uniform thickness is less than μm, the shape accuracy of the processed substrate is 1 μm in parallelism, and the thickness difference between wafers is ±1 μm.
It can be kept below m. In addition, compared to traditional manual methods, the gluing time can be shortened, productivity can be improved, and even and highly accurate gluing can be performed without relying on skilled workers. be.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view showing an embodiment of a wafer bonding device according to the present invention, FIG. 2 is a cross-sectional view of a suction mechanism, and FIGS. 3 a to 3 c are diagrams for explaining wafer bonding. be. DESCRIPTION OF SYMBOLS 1... Wafer bonding device, 2... Wafer carrier, 3... Wafer, 3a... Notch, 4... Chucking station, 24... Shaft, 28... Adsorption plate, 30... Case, 35... ...Center hole, 37...
...Permanent magnet, 40...Electromagnet, 42...Spray chamber,
43... Upper entrance, 45... Air curtain, 46
... Sprayer, 48 ... Mounting cylinder, 57 ... Drying room,
60... Index plate, 62... Cushion material, 63...
...Adhesive plate, A...Wafer supply mechanism, B...Elevator mechanism, C...Adsorption mechanism, D...Transfer mechanism, E
...Rotation stop mechanism.

Claims (1)

[Scope of Claims] 1. A suction device having a wafer supply mechanism that supplies wafers stored in a wafer carrier one by one to a chucking station, and a wafer suction plate that suctions and holds the wafers supplied to the chucking station. a mechanism, a transfer mechanism for transferring the adsorption mechanism, a spraying chamber for spraying an adhesive onto one surface of the wafer transferred by the transfer mechanism, and a drying chamber for drying and evaporating the solvent in the adhesive. , an indexing plate for adhering the wafer to a predetermined position on the adhesion plate, and the suction mechanism has an inner hole communicating with a wafer suction hole provided in the suction plate, and the suction mechanism A hollow shaft that is rotatably held, a case that holds this shaft and is connected to an exhaust pump and is moved up and down, and a permanent magnet and an electromagnet that are provided opposite the case and the adsorption plate. A wafer bonding apparatus comprising: a rotation stop mechanism for rotating the suction plate and stopping it at a predetermined position. 2. Claim 1, characterized in that the spray chamber is provided with an air curtain at the upper entrance and a mounting tube for adjusting the spray airflow at the lower part.
The wafer bonding device described in Section 1. 3. The wafer bonding apparatus according to claim 1, wherein the index plate has a cushion material for mitigating the impact when bonding the wafer to the bonding plate.