JP2000340636A - Device wafer transfer method - Google Patents

Abstract

(57) Abstract: A method for transferring a flexible device wafer having a thickness of 30 to 120 μm. SOLUTION: A back surface ground surface or an etched surface of a device wafer having a device pattern on a surface of a wafer substrate and having a thickness of 30 to 120 μm has a diameter 2/3 to 4/3 times the device wafer diameter. A method for transporting a device wafer, wherein a plurality of small holes provided on the surface of the suction pad of a transfer robot having a circular suction pad on an arm are suctioned to transfer the device wafer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer substrate having a device pattern formed on a surface thereof having a thickness of 30 to 120.
The present invention relates to a method of transferring a μm device wafer from above a cleaning mechanism of a backside grinding device to a spinner of an etching device, or from above a spinner of an etching device to a protective tape peeling mechanism in a previous process of a dicer.

[0002]

2. Description of the Related Art A conventional IC chip for an IC card having a thickness of 2 to 5 mm is obtained by curing the device pattern surface of a device wafer having a thickness of 500 to 750 μm, in which a device pattern is formed on the surface of a silicon substrate, by UV irradiation. After coating with an adhesive resin protective tape, the silicon layer on the opposite side of this protective tape is back-ground, and the back-ground surface is etched to reduce the thickness of the device wafer to 250 to 450 μm, and then cured by UV irradiation. Then, peel off the protective tape from the device wafer, apply UV-curable adhesive resin protective tape on the back surface opposite to the pattern surface of the device wafer, and then cut and cut along the grid lines of the device wafer pattern with a dicer. Manufacturing.

Conventional transfer of a device wafer from a storage cassette to a grinding machine of a backside grinding device, transfer from a grinding machine to a storage cassette, transfer of a device wafer from a storage cassette to a spinner of an etching device, and transfer of a device wafer from a spinner to a storage cassette. The transfer, the transfer of the device wafer from the storage cassette to the protective tape peeling device, and the transfer of the device wafer from the storage cassette to the dicer are performed by a transfer robot having a claw for holding the outer peripheral end surface of the device wafer on the arm (Patent No. 28)
No. 88381) or a transfer pad for sucking a wafer into a small hole provided on the surface of the nail so that the center of the wafer is positioned at the center of the nail is used (Japanese Patent Laid-Open No. 11-121580).
issue).

As compared with a prepaid magnetic card having a thickness of 150 to 300 μm, an IC card has a thickness of 2 to 5 mm and is hard to carry in a wallet or a business card holder. Also,
Manufacturing costs are high. Therefore, the thickness is 30-120μ
m, preferably a smart card having a rewritable recording thickness of 100 to 300 μm using an IC chip of 30 to 80 μm has been proposed and said to be feasible in 2000.

The thickness is 30 to 120 μm, preferably 30
A device wafer of up to 80 μm is theoretically possible by increasing the back grinding amount and etching amount of the silicon substrate. When actually manufactured, a device wafer having a thickness of 30 to 120 μm shows flexibility, and warps in a concave or convex shape depending on the design of the pattern surface and the type of metal or insulating material. It has been found that it is difficult to carry using a carrying robot having a claw that clamps an end face on an arm.

[0006]

SUMMARY OF THE INVENTION The present invention has a thickness of 30.
It is an object of the present invention to provide a method of transferring a device wafer as thin as 120 μm.

[0007]

According to the present invention, there is provided a semiconductor device having a device pattern on a surface of a wafer substrate having a thickness of 30 to 1 mm.
A large number of back side grinding or etching surfaces of a 20 μm device wafer are provided on the surface of the suction pad of a transfer robot having a circular suction pad having a diameter of 2/3 to 4/3 times the device wafer diameter on an arm. The present invention provides a method for transporting a device wafer, wherein the device wafer is transported by suction by reducing the pressure of the small holes.

Since the device wafer is suctioned and transported on the surface using a suction pad having a large diameter, the device wafer has a flat surface during transport, and can be transported easily.

According to the present invention, in the above-mentioned method for transporting a device wafer, the ground surface of the device wafer having a thickness of 30 to 120 μm and placed on a spinner of a cleaning mechanism of the rear surface grinding apparatus may be adjusted to a diameter of 2 mm. The suction is performed by depressurizing a large number of small holes provided on the surface of the suction pad of the transfer robot having the arm having a circular suction pad having a diameter of ３ to ／ and the device wafer is placed on the spinner of the etching apparatus. Is transported.

By inlining the backside grinding device and the etching device and adopting the above-described transfer method, the device wafer is stored in the storage cassette after the backside grinding as in the related art.
Then, the work of manually transporting the storage cassette to the etching apparatus and placing it on the etching apparatus base could be omitted.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail with reference to the drawings. 1 is a top view of a grinding device in which an etching device is inlined, FIG. 2 is a perspective view showing a portion of the grinding device, FIG. 3 is a perspective view of a cleaning mechanism of the grinding device, and FIG. A sectional view, FIG. 5 is a sectional view of a spinner portion of the etching apparatus, and FIG. 6 is B in FIG.
FIG. 7 is a front view of the partition wall of the grinding apparatus and the etching apparatus as viewed from plane CC in FIG. 1, and FIG. 8 is a front view of the partition wall of the grinding apparatus and the etching apparatus. FIG. 9 is a cross-sectional view as viewed from the plane D, FIG.
Is a view of the arm and the suction pad of the articulated transfer robot provided in the etching apparatus as viewed from below, and FIG. 11 is a sectional view of the suction pad portion.

In the grinding apparatus 1 in which the etching apparatuses shown in FIGS. 1 and 2 are inlined, the grinding apparatuses 101 are arranged in the front row with a pair of cassettes 117 on the left and right sides, and a temporary wafer is placed on the base at the rear of the left cassette. The mounting table 106 is arranged in the next row with the wafer cleaning mechanism 113 shown in FIG. 3 as a pair at the rear of the right cassette, and an index is formed at a position where the center of the base of the wafer temporary mounting table 106 and the rear of the wafer cleaning mechanism 113 is hollowed out. A turntable 108 is provided, and the index turntable is mounted around the axis of the harm table.
The base wafer chuck mechanisms 107, 107, 107 are provided at equal intervals so as to be rotatable on planets, and a wafer loading / wafer unloading zone s1 and a coarse grinding zone s are provided.
2 and a finishing grinding zone s3, and a grinding wheel 111 suitable for a square grinding zone is provided on a frame 111 erected from a base in the rear row of the index turntable 108.
Grinding mechanisms in which b and 111d are supported on spindle shafts 111a and 111c are provided corresponding to the wafer chuck mechanisms located in each grinding zone.

An elevating mechanism 10 is provided substantially at the center of the base between the row of the pair of cassettes and the row of the temporary mounting table and the cleaning mechanism.
3. An articulated transfer robot 115 having a rotation drive mechanism, a wafer alignment measurement mechanism, and a control mechanism for driving the respective arms 115a, 115b, 115c is erected, and the device wafer on the temporary table is loaded on an index turntable. / Wafer unloading zone s1
Can be transferred to the chuck mechanism. 1 provided on the left and right of the approximate center of the base on which the index turntable is provided
The suction pads 112a, 112a provided on the handle 112 rotatably mounted on the pair of shafts and having a diameter of 2/3 to 4/3 times the diameter of the device wafer are respectively used for wafer loading / wafer loading of the device wafer of the temporary mounting table. The back-ground device wafer on the chuck mechanism in the unloading zone and on the chuck mechanism in the wafer loading / wafer unloading zone is transferred to the spinner (porous ceramic wafer temporary mounting table + wafer support auxiliary plate) in the cleaning mechanism. I do.

Each of the chuck mechanisms of the index turntable includes a chuck cleaning mechanism 109b attached to a driving body that can move in the left-right direction on a screw rod provided on a frame 110 erected from a base, and a ceramic chuck cleaner 10.
Washed by 9a. This grinding device 101 is used for the wall 11
8 and a double door 119.

FIG. 3 shows a cleaning mechanism 113 of the grinding apparatus.
(Japanese Patent Application No. 10-140408).
Reference numeral 2 denotes a porous ceramic wafer temporary mounting table that is vertically movable and rotatably supported on a hollow shaft. Reference numeral 3 denotes a wafer support auxiliary plate on which a plurality of porous ceramic plates 4, 4, 4,. 5 is a device wafer positioning pin, 6 is a jacket, 7 is a rinse (pure water) supply nozzle,
8 is an air supply nozzle.

The device wafer transported onto the spinner (porous ceramic wafer temporary mounting table 2 + wafer support auxiliary plate 3) of the cleaning mechanism by the suction pad 112a is fixed by depressurizing the hollow shaft, and rotating the hollow shaft. The device wafer w is rotated, and pure water is sprayed from the nozzle 7 onto the back surface ground surface to clean the ground surface. After the cleaning is completed, pure water is oozed out from the wafer support auxiliary plates 4, 4, 4 to float the device wafer, and the temporary mounting table is slightly raised, and while rotating the hollow shaft, dry air is blown from the nozzle 8 to blow the device wafer. Perform drying.

In the etching apparatus 20 shown in FIGS. 1 and 4 to 7, a first wall 21 surrounds the entire etching apparatus, a second wall 22 surrounds a spinner 23,
4 and 24 are cassettes, 25 is an articulated transfer robot, 2
5a, 25b, 25c are arms, 25d is a shaft, 25e is 2/3 to 4/3 times the device wafer diameter, preferably 7 /
8 to 1/1 diameter suction pad, 25f is a rotating shaft, 25
g and 25g are air flow paths. A number of small holes 25h having a diameter of 0.3 to 1 mm are formed on the surface of the suction pad 25e on which the device wafer is suctioned. FIG. 10 and FIG. 11 show enlarged portions of the arm and the suction pad. Suction pad 25
e has a thickness of about 2 mm, and the height of the air flow path 25 g is about 0.2 mm.
It is about 5 mm. The air passage 25g of the shaft 25d communicates with the air passage 25g of the suction pad, and the device wafer w
During adsorption, the pressure is reduced.

Reference numeral 26 denotes a wafer mounting plate (spinner); 27, a spinner rotation drive shaft; 28, an etching solution supply nozzle provided on a rotary drive shaft 28a; 29, a rinsing solution supply and supply provided on a rotation drive shaft 29a; Nozzle for air supply, 30 for jacket, 31 for hood, 32 for lifting mechanism, 33
And 35 are gate valves, and 34 and 36 are gates (openings) through which the arms of the transfer robot 25 can enter and exit.

Opening and closing of the gates 34, 36 is performed, for example, by hinges 39.4 on shafts 37, 38 as shown in FIGS.
0, the plates 41 and 42 are attached, and the shaft 3
Plates 41 and 42 are attached using pulley 45 running around 7, 38 and shaft 43, idle roll 44, gear 46, gear 47 attached to the end of shaft 38 and a pulley drive mechanism (not shown). The rotation is performed by rotating the shafts 37 and 38. The opening and closing of the gates 34 and 36 is not limited to the above-mentioned rotary type, but may be a type in which the shutter plate is moved up and down.

The back surface grinding of the device wafer w using the grinding apparatus 1 in which the etching apparatus 20 shown in FIG. 1 is inlined with the grinding apparatus 101 is performed through the following steps. (1) The device wafer w is loaded from the wafer loading cassette 117 onto the suction pad of the articulated transfer robot 115.
And put it on the temporary mounting table 106. (2) The index turntable 118 is rotated 120 degrees, and then the device wafer on the temporary table is attracted to the transport pad 112a, and the transport pad is rotated to load the device wafer into the wafer loading / wafer unloading zone s1 of the index turntable. Is transferred to the chuck mechanism a of the cassette, and the wafer loading cassette 117 is transferred to the suction pad of the articulated transfer robot in the meantime.
The device wafer is further sucked and placed on a temporary table.

(3) Index turntable 11
After rotating the chuck mechanism a to the coarse grinding zone s2 and moving the chuck mechanism b to the wafer loading / wafer unloading zone s1, the first spindle shaft 111a is lowered and the grinding wheel 111 is rotated.
b is pressed against the back surface of the device wafer, and the chuck mechanism a and the first spindle shaft are rotated to roughly grind the back surface of the wafer. Then, the first spindle shaft is raised, and during this time, the device wafer on the temporary table is moved. Is transferred to the chuck mechanism b in the wafer loading / wafer unloading zone s1 of the index turntable by the transfer pad 112, and the articulated transfer robot 11 is transferred.
5, the device wafer in the wafer loading cassette 117 is placed on the temporary table 106.

(4) Index turntable 11
After rotating the chuck mechanism a to the finish grinding zone s3 by rotating the chuck mechanism 120 by 120 degrees, moving the chuck mechanism b to the coarse grinding zone s2, and moving the chuck mechanism c to the wafer loading / wafer unloading zone s1, the second The spindle 111c is lowered to press the grindstone 111d against the backside of the device wafer, and the chuck mechanism a and the spindle are rotated to finish grind the wafer.
The second spindle shaft is raised, during which the first spindle shaft 111a is lowered to press the grindstone 111b against the back surface of the wafer, and the chuck mechanism b and the spindle shaft are rotated to roughly grind the wafer. The first spindle shaft is raised, and the wafer on the temporary mounting table 106 is transferred to the chuck mechanism c of the wafer loading / wafer unloading zone s1 of the index turntable by the transport pad 112 on the left side.
The device wafer in the wafer loading cassette 117 is temporarily stored on the temporary mounting table 106 by using the articulated transfer robot 115.
Put on top.

(5) One index turntable
By rotating the chuck mechanism 20 by 20 degrees, the chuck mechanism a was moved to the wafer loading / wafer unloading zone s1, the chuck mechanism b was moved to the finish grinding zone s3, and the chuck mechanism c was moved to the rough grinding zone s2. The device wafer is transferred to the cleaning mechanism 113, and the back grinding surface of the device wafer is cleaned and dried.
The suction pad 25e is moved onto the device wafer on the cleaning mechanism 113 of the back surface grinding device 101 through the opened gate 34, and after the device wafer is sucked, the device wafer is passed through the gate 36 in the etching device 20 via the gate 34,
Place the back-ground device wafer on the spinner 26,
The suction pad 25e of the articulated transfer robot 25 is returned to the standby position, the gates 34 and 36 are closed, the back surface of the device wafer is etched, washed with a cleaning liquid, and then dried by blowing air from an air supply nozzle. Then, the device wafer is sucked to the suction pad of the articulated transfer robot 25 and transferred to a protective tape peeling mechanism (not shown).

On the other hand, by rotating the transfer pad 112 on the left side, the device wafer on the temporary table 106 is transferred to the chuck mechanism a in the wafer loading / wafer unloading zone s1 of the index turntable.
The device wafer is sucked from the wafer loading cassette to the suction pad of the articulated transfer robot 115, and the device wafer is placed on the temporary mounting table. Meanwhile, the second spindle shaft is lowered to press the grindstone against the device wafer back surface, The chuck mechanism b and the spindle shaft are rotated to finish grind the wafer. Thereafter, the second spindle shaft is raised, and at the same time, the first spindle shaft is lowered to press the grindstone against the device wafer. The rough grinding of the wafer is performed by rotating c and the spindle shaft, and then the first spindle shaft is raised.

(6) One index turntable
By rotating the chuck mechanism by 20 degrees, the chuck mechanism b is moved to the wafer loading / wafer unloading zone, the chuck mechanism c is moved to the finish grinding zone, and the chuck mechanism a is moved to the coarse grinding zone, and the wafer finished and ground by the transfer pad is moved to the cleaning mechanism. After the transfer and cleaning of the wafer, the device wafer that has been finished and cleaned by the suction pad 25e of the articulated transfer robot 25 is suctioned, transferred to the spinner of the etching apparatus 20, and etched as described above. ,
After washing and drying, it is transported to the protective tape peeling mechanism.

On the other hand, by rotating the transfer pad 112 on the left side, the device wafer on the temporary table 106 is transferred to the chuck mechanism b in the wafer loading / wafer unloading zone s1 of the index turntable.
The device wafer is sucked from the wafer loading cassette to the suction pad of the articulated transfer robot 115, and the device wafer is placed on the temporary mounting table. Meanwhile, the second spindle shaft is lowered to press the grindstone against the device wafer back surface, The chuck mechanism c and the spindle shaft are rotated to finish grind the wafer, and then the second spindle shaft is raised, and at the same time, the first spindle shaft is lowered to press the grindstone against the device wafer, and the chuck mechanism is rotated. a and the spindle shaft are rotated to roughly grind the wafer, and then the first spindle shaft is raised.

(7) One index turntable
By rotating the chuck mechanism by 20 degrees, the chuck mechanism c is moved to the wafer loading / wafer unloading zone, the chuck mechanism a is moved to the finishing grinding zone, and the chuck mechanism b is moved to the rough grinding zone, and the wafer that has been finished and ground by the transfer pad is moved to the cleaning mechanism. After the transfer and cleaning of the wafer, the device wafer that has been finished and cleaned by the suction pad 25e of the articulated transfer robot 25 is suctioned, transferred to the spinner of the etching apparatus 20, and etched as described above. ,
After washing and drying, it is transported to the protective tape peeling mechanism.

On the other hand, the device wafer on the temporary placement table 106 is transferred to the chuck mechanism c in the wafer loading / wafer unloading zone s1 of the index turntable by rotating the transfer pad 112 on the left side.
The device wafer is sucked from the wafer loading cassette to the suction pad of the articulated transfer robot 115, and the device wafer is placed on the temporary mounting table. Meanwhile, the second spindle shaft is lowered to press the grindstone against the device wafer back surface, The chuck mechanism a and the spindle shaft are rotated to finish grind the wafer. Thereafter, the second spindle shaft is raised, and at the same time, the first spindle shaft is lowered to press the grindstone against the device wafer. The wafer b is roughly ground by rotating b and the spindle shaft, and then the first spindle shaft is raised.

Thereafter, the steps (5), (6) and (7) are repeated, and the back side of the device wafer is ground and etched to continuously manufacture device wafers having a thickness of 30 to 120 μm. The thickness of the device pattern surface of the device wafer varies depending on the number of device layers and the manufacturing method, but is preferably about 1 to 15 μm for a smart card. Therefore, the thickness of the silicon substrate is calculated to be 15 to 119 μm in reverse. The strength of the device wafer having a thickness of 30 to 120 μm is about 5 to 100 Newton / 25 mm width.

[0030]

According to the present invention, the grinding device 1 with the etching device attached to the back surface grinding device 101 in which the etching device 20 is connected in an in-line manner is compared with a conventional back surface grinding device and an etching device separately provided. The device can be simplified and compacted as a whole, and after the back side of the device wafer is ground, there is no need to store the device wafer in a cassette. The wafer can be transferred.

The method of transferring a device wafer having a thickness of 30 to 120 μm according to the present invention is a method in which the back surface ground surface and the etched surface of the device wafer are sucked on the suction pad surface of the transfer robot, and the diameter of the suction pad is adjusted by the device. Since the surface area is increased to 2/3 to 4/3 times the diameter of the wafer, the warpage of the device wafer is eliminated by the device wafer surface being attracted to the suction pad surface by the pressure reduction of the suction pad, and the transfer becomes easy.

[Brief description of the drawings]

FIG. 1 is a top view of a backside grinding device in which an etching device is inlined.

FIG. 2 is a perspective view of a back surface grinding device.

FIG. 3 is a perspective view of a cleaning mechanism of the grinding device.

FIG. 4 is a sectional view of the etching apparatus taken along line AA in FIG. 1;

FIG. 5 is a sectional view of a spinner portion of the etching apparatus.

FIG. 6 is a top view as viewed from plane BB in FIG. 5;

7 is a front view of a partition wall of the grinding device and the etching device as viewed from a plane CC in FIG. 1;

FIG. 8 is a sectional view of a partition wall of the grinding device and the etching device as viewed from a plane DD in FIG. 1;

FIG. 9 is a view as seen in the direction of arrows EE in FIG. 7;

FIG. 10 is a view of an arm and a suction pad of the articulated transfer robot as viewed from below.

FIG. 11 is a partial sectional view of a suction pad.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 etching device inline back grinding device 101 back grinding device 113 cleaning mechanism of back grinding device 20 etching device 25 articulated transfer robot 25 e suction pad 26 spinner of etching device w device wafer

 ──────────────────────────────────────────────────の Continuing from the front page (72) Inventor Hirotaka Konogi 3009 Kamiyori, Atsugi-shi, Kanagawa Prefecture Okamoto Machine Tool Works, Ltd. F-term in the Semiconductor Division (reference) 5F031 CA02 GA24 GA43 GA47 HA13 MA22 MA23 MA24 MA38

Claims (2)

[Claims] 1. The method according to claim 1, wherein a device pattern is formed on the surface of the wafer substrate, and the back surface or the etched surface of the device wafer having a thickness of 30 to 120 μm is reduced to 2/3 to 4/3 times the device wafer diameter. A method of transferring a device wafer, comprising: transferring a device wafer by suction by reducing a large number of small holes provided on a surface of the suction pad of a transfer robot having a circular suction pad provided on an arm. 2. A backside grinding surface of a device wafer having a thickness of 30 to 120 μm placed on a spinner of a cleaning mechanism of the backside grinding device has a diameter 2/3 to 4/3 times the diameter of the device wafer. 2. The device according to claim 1, wherein a large number of small holes provided on the surface of the suction pad of the transfer robot having the circular suction pad on the arm are suctioned by reducing the pressure, and the device wafer is transferred onto the spinner of the etching apparatus. 3. The method for transporting a device wafer according to item 1.