KR20120106615A - Protection film coating method and protection film coating device - Google Patents

Abstract

PURPOSE: A method and apparatus for coating a protective film are provided to efficiently coat the surface of a wafer with resin coating films. CONSTITUTION: A concave part(9) is formed on a wafer and a ring type frame by relatively lifting the ring type frame with regard to the wafer. A water layer(61a) is formed on the surface of the wafer by supplying water. Liquid resin(710) is dropped in the center of the wafer. The surface of the wafer is coated with the resin coating film by dispersing the water layer through the rotation of a spinner table(3) and expanding the dropped liquid resin.

Description

PROTECTION FILM COATING METHOD AND PROTECTION FILM COATING DEVICE}

The present invention relates to a method and apparatus for coating a resin film on the surfaces of various wafers.

A plurality of devices, such as ICs and LSIs, are partitioned by a ratio scheduled line and formed on the surface of the wafer, and the laser irradiation is performed along the division scheduled line to divide the individual devices, and are used in various electronic devices and the like (for example, a patent). See Document 1).

When a laser beam is irradiated onto a wafer made of silicon or the like, debris scatters and adheres to the surface of the wafer, thereby degrading device quality. Thus, the surface of the wafer is made of polyvinyl alcohol (PVA) or the like. The technique which coats the liquid resin to form a protective film, protects the surface of a device with a protective film, and prevents a quality fall even if a debris scatters is proposed by the present applicant, and is actually used (for example, refer patent document 2). .

However, since the liquid resin and the wafer have low affinity, for example, when a protective film having a thickness of 4 m is formed on the surface of a 300 mm diameter wafer, the liquid resin such as PVA coated as the protective film is about 0.3 cc. In spite of this, a liquid resin of 19 cc to 30 cc is actually used, and almost 98% to 99% of them are discarded, and there is a problem that it is very uneconomical.

Therefore, in order to solve such a problem, the method and apparatus which can efficiently coat liquid resins, such as PVA, by forming the water layer which covers the surface of a wafer, and dropping liquid resins, such as PVA, Is proposed and actually used (for example, refer patent document 3).

Patent Document 1: Japanese Patent Application Laid-Open No. 6-120334 Patent Document 2: Japanese Patent Application Laid-Open No. 2004-188475 Patent Document 3: Japanese Patent Laid-Open No. 2010-125351

However, due to the water repellency of the wafer and the inclination of the device, there is a problem that a time of 100 seconds or more is required to form a water layer covering the surface of the wafer.

This invention is made | formed in view of such a problem, and is what makes it possible to coat liquid resin, such as PVA, on a wafer efficiently.

1st invention is a protective film formation method which forms a protective film by coating a liquid resin on the surface of a wafer using the protective film forming apparatus containing the spinner table which hold | maintains a wafer to the protective tape attached to the ring-shaped frame. It is related and is comprised by each of the following processes.

(1) a frame holding step of holding a ring-shaped frame with a spinner table;

(2) a wafer holding step of holding the surface of the wafer upward with a spinner table;

(3) a concave forming step of raising the ring-shaped frame relative to the wafer to form concave portions of the ring-shaped frame and the wafer;

(4) an aqueous layer forming step of forming a water layer covering the surface of the wafer held on the spinner table after the recess forming step;

(5) a liquid resin dropping step of dropping liquid resin into the center of the wafer in the water layer;

(6) A resin film coating step of rotating a spinner table to disperse the water layer by centrifugal force acting on the water layer in accordance with the rotation of the wafer, expanding the dropped liquid resin, and covering the resin film on the surface of the wafer.

In the above protective film forming method, in the resin film coating step, by lowering the frame relative to the wafer, the induced shape is returned to a flat shape, thereby expanding the liquid resin dropped along with the expansion of the water layer, thereby increasing the surface of the wafer. It is preferable to form a resin film on the substrate.

2nd invention is related with the protective film coating apparatus suitable for implementation of the said protective film formation method, The wafer holding means which hold | maintains the wafer adhered to the protective tape attached to the ring-shaped frame, and the ring-shaped frame holding means which hold | maintains a ring-shaped frame. A spinner table comprising: a rotation drive means for rotating the spinner table; water supply means for supplying water to the wafer held on the spinner table; and liquid resin supply means for supplying liquid resin to the wafer held on the spinner table. And up and down operation means for relatively vertically operating the ring-shaped frame holding means and the wafer holding means.

In the resin film coating process according to the present invention, the ring-shaped frame in which the wafer is adhered to the protective tape mounted on the ring-shaped frame is raised relative to the wafer to form recesses having a protruding shape with the ring-shaped frame and the wafer. After water was supplied to form a water layer on the surface of the wafer, a liquid resin was added dropwise to the center of the wafer, the spinner table was rotated to disperse the water layer by centrifugal force, and the dropped liquid resin was expanded to provide a resin on the surface of the wafer. Since it coats a film, liquid resin can be coat | covered evenly over the whole surface of a wafer efficiently. In addition, since most of the dropped liquid resin is coated on the surface of the wafer, it is very economical.

1 is a perspective view showing an example of a protective film coating device.
2 is a cross-sectional view schematically showing a state in which a wafer supported on a ring-shaped frame is held on a spinner table via a protective tape.
3 is a cross-sectional view schematically illustrating a state in which a concave portion is formed of a surface of a wafer and a protective tape by raising a ring-shaped frame.
4 is a sectional view schematically showing a state in which water is supplied to the recess to form a water layer on the surface of the wafer.
5 is a cross-sectional view schematically showing a state in which a liquid resin is dropped on the water layer.
FIG. 6 is a cross-sectional view schematically showing a state in which a spinner table is rotated to scatter water layers to form a resin film on the wafer surface.

1. Device Configuration

The protective film coating apparatus 1 shown in FIG. 1 is an apparatus which forms a protective film by coating liquid resin on the surface of a wafer, and includes the spinner table 3 which is driven by the rotation drive means 2, and is rotatable.

The wafer W held by the spinner table 3 is adhered to the protective tape T mounted to block the opening of the ring-shaped frame F. As shown in FIG. The spinner table 3 includes a wafer (4) for holding a wafer W in a state of being adhered to a protective tape T attached to the ring-shaped frame F, and a wafer (via a protective tape T). It consists of the ring-shaped frame holding means 5 which hold | maintains the ring-shaped frame F integrated with W).

Around the spinner table 3, water supply means 6 for supplying water to the wafer W held by the wafer holding means 4 of the spinner table 3 is provided. The water supply means 6 is connected to a water source (not shown), which is pivotable, and a base portion 60 that extends in a horizontal direction from the base portion 60 and a jetting portion 61 whose tip portion is curved downward. It is composed.

Around the spinner table 3, liquid resin supply means 7 for supplying a liquid resin to the wafer W held by the wafer holding means 4 of the spinner table 3 is provided. The liquid resin supply means 7 communicates with a tank of liquid resin (not shown), which is pivotable, and a dropping portion 71 extending in the horizontal direction from the base portion 70 and the tip portion curved downward. It consists of.

The wafer holding means 4 raises and lowers the holding table 40 which can suction hold the wafer W via the protective tape T, the shaft portion 41 connected to the lower end of the holding table, and the shaft portion 41. The lift drive part 42 which makes it easy to carry out, and the up-down operation means 43 which moves the holding table 40 up and down by the axial part 41 and the lift drive part 42 is comprised. As shown in FIG. 2, the holding table 40 includes the suction part 40a which communicates with the suction source which is not shown in figure. As the lift drive section 42 and the shaft section 41 in FIG. 1, for example, an air cylinder and a piston rod can be used, and the vertical movement means 43 includes a ring-shaped frame holding means 5 and a wafer holding means 4. It serves as a means for operating relatively up and down. After FIG. 2, the vertical operation means 43 is not shown.

As shown in FIG. 2, the ring-shaped frame holding means 5 is attached to the support 50 which supports the ring-shaped frame F from below, and the press which is attached to the support 50 and presses the ring-shaped frame F from the upper side. And a plurality of shaft portions 52 connected to the lower end of the support portion 50, and a plurality of lift driving portions 53 for lifting the shaft portions 52, and the shaft portion 52 and the lift driving portion 53. The vertical movement means 54 which moves the support stand 50 up and down is comprised by (). The press part 51 can rotate about the rotating shaft 510 by injection of air. As the lift drive unit 53 and the shaft unit 52, for example, an air cylinder and a piston rod can be used. The vertical operation means 43 functions as a means for relatively vertically operating the ring-shaped frame holding means 5 and the wafer holding means 4.

As shown in FIG. 2, the rotation drive means 2 for rotating the spinner table 3 includes a motor 20, a rotation shaft 21 that is rotationally driven by the motor 20, and a rotation shaft 21. It consists of the base stand 22 which rotates with rotation, and the lifting drive part 53 is being fixed to the base stand 22. As shown in FIG. When the motor 20 rotates the rotating shaft 21, the base stand 22 also rotates and the wafer holding means 4 and the frame holding means 5 rotate. The base stand 22 is comprised from the flat part 220 and the drooping part 221 lined down from the circumferential edge.

A supporting means 8 is provided below the spinner table 3. The supporting means 8 includes an inner wall 80 located at the inner circumference of the lower part 221 constituting the base stand 22, an outer wall 81 located at the outer circumference of the lower part 221, and The bottom plate 82 connects the lower end of the inner wall 80 and the lower end of the outer wall 81.

2. Protective film coating method

Next, the operation of the protective film coating device 1 in the case of coating the protective film on the surface W1 of the wafer W will be described. As shown in FIG. 2, the ring-shaped frame F is affixed to the outer periphery of the protective tape T, the opening part of the ring-shaped frame F is blocked by the protective tape T, and the protective tape T of the blocked part is shown. ) Is attached to the back surface W2 of the wafer W. In this way, the wafer W is integrated with and supported by the ring-shaped frame F via the protective tape T, and the surface W1 of the wafer W is exposed upward.

(1) frame maintenance process

As shown in FIG. 2, the ring-shaped frame F integrated with the wafer W via the protection tape T is arrange | positioned at the support stand 50 of the frame holding means 5 of the spinner table 3. And the press part 51 is rotated toward the support stand 50 (in the direction of arrow A in FIG. 2), and the ring-shaped frame F is clamped and hold | maintained between the support stand 50 and the press part 51. FIG.

(2) wafer holding process

As shown in FIG. 2, the wafer W integrated with the ring-shaped frame F is disposed on the holding table 40 of the wafer holding means 4 of the spinner table 3 via the protective tape T. As shown in FIG. Then, a negative pressure is applied to the suction part 40a, so that the surface W1 of the wafer W becomes the upper side and is exposed, and the back surface W2 side of the wafer W is placed through the protective tape T. Keep aspirated. The frame holding step and the wafer holding step may be performed either first or both steps may be performed simultaneously.

(3) recess formation process

After the frame holding step and the wafer holding step, the ring-shaped frame F is operated to be lifted relative to the wafer W. FIG. Specifically, the up-down operation means 54 of the frame holding means 5 shown in FIG. 3 raises the support 50, or the up-down operation means 43 of the wafer holding means 4 is the holding table 40. As shown in FIG. The frame holding means (5) and the wafer holding means (4) by lowering or lowering the support table (54) by raising the support (50) and the up and down operating means (43) by lowering the holding table (40). It is operated up and down relatively. In this way, when the ring-shaped frame F is raised relative to the wafer W, a height difference occurs between the wafer W and the frame F, and the inclined surface 90 is formed by the protective tape T. As shown in FIG. And the surface W1 of the wafer W is made into the bottom face 91, and the bottom surface 91 and the inclined surface 90 form the recessed part 9 of the induced shape.

(4) water layer forming process

After the recess forming step, as shown in FIG. 4, the water supply means 6 is pivoted, and the ejection portion 61 is moved upward of the wafer W held by the spinner table 3 to form the ejection portion ( Water 610 is discharged from 61. As a result, water accumulates in the concave recess 9, and the water layer 61a covering the surface W1 of the wafer W is formed.

(5) Liquid resin dropping process

After the water layer forming step, the ejection portion 61 of the water supply means 6 is retracted from the upper side of the wafer W, and as shown in FIG. 5, the liquid resin supply means 7 is swiveled to form the dropping portion 71. Is moved above the center of the wafer (W). And the liquid resin 710 is dripped from the dripping part 71 in the state. For example, when the diameter of the wafer W is 300 mm and the resin of 4 µm thickness is to be coated, the liquid resin 710 of about 2 cc is dropped. As the liquid resin 710, for example, polyvinyl alcohol having a viscosity of 50 to 70 centipoise can be used. The dropped liquid resin 710 stays on the water layer 61a by the viscosity.

(6) resin film coating process

After the liquid resin dropping step, as shown in FIG. 6, the ring-shaped frame holding means 5 is lowered relative to the wafer holding means 4, whereby the induced recess 9 is not formed, that is, the wafer. There is no step between W and the ring-shaped frame F, and the protection tape T returns to the flat shape which became horizontal to rotate the spinner table 3. Then, the centrifugal force acts on the water layer 61a according to the rotation of the wafer W, and the water 61b which formed the water layer 61a scatters around the outer periphery by the centrifugal force, and the liquid resin 710 which dripped was dripped. Is extended around the outer side in the horizontal direction and spreads evenly on one surface of the surface W1 of the wafer W, so that the resin film 71a is formed on the surface W1 of the wafer W. As shown in FIG.

As described above, the ring-shaped frame F is raised relative to the wafer to form a recess, water is supplied to the recess to form a water layer on the surface of the wafer, and the liquid resin is dropped thereon, and then the wafer is rotated. The resin film can be efficiently coated on the surface of the wafer by spin coating the liquid resin by scattering the aqueous layer.

1: protective film coating device 2: rotation drive means
20: motor 21: rotating shaft
22: base stand 220: flat part
221: lower part 3: spinner table
W: wafer W1: surface
W2: Backside T: Masking Tape
F: ring-shaped frame 4: wafer holding means
40: holding table 40a: suction part
41: shaft portion 42: lifting drive portion
43: vertical operation means 5: ring-shaped frame holding means
50: support 51: compression
510: rotating shaft 52: shaft portion
53: lift drive unit 54: vertical operation means
6: water supply means 60: base part
61: jet 610: water
61a: water layer 7: liquid resin supply means
70: base portion 71: dripping portion
8: supporting means 80: inner wall
81: outer wall 82: bottom plate
9: recess 90: inclined surface
91: bottom surface

Claims (3)

A protective film coating method of forming a protective film by coating a liquid resin on the surface of a wafer by using a protective film forming apparatus including a spinner table for holding a wafer adhered to a protective tape mounted on a ring frame.
A frame holding step of holding the ring-shaped frame in the spinner table;
A wafer holding step of holding the surface of the wafer upward in the spinner table;
A concave forming step of raising the ring-shaped frame relative to the wafer to form concave portions of the ring-shaped frame and the wafer;
An aqueous layer forming step of forming a water layer covering the surface of the wafer held on the spinner table after the recess forming step;
A liquid resin dropping step of dropping a liquid resin in the center of the wafer in the water layer;
Resin coating process which rotates the spinner table, scatters the aqueous layer by centrifugal force acting on the aqueous layer with the rotation of the wafer, expands the dropped liquid resin, and coats the resin film on the surface of the wafer.
Protective film coating method comprising a. The liquid resin coating process according to claim 1, wherein in the resin film coating step, by dropping the frame relative to the wafer, the induced shape is returned to a flat shape, thereby expanding the liquid resin dropped along with the expansion of the water layer. The protective film coating method which forms a resin film on the surface of the said wafer. A protective film coating device for forming a protective film by coating a liquid resin on the surface of a wafer,
A spinner table including wafer holding means for holding a wafer adhered to a protective tape mounted to the ring-shaped frame, and ring-shaped frame holding means for holding the ring-shaped frame;
Rotation drive means for rotationally driving the spinner table;
Water supply means for supplying water to the wafer held on the spinner table;
Liquid resin supply means for supplying a liquid resin to a wafer held on the spinner table;
Vertical operation means for relatively vertically operating the ring-shaped frame holding means and the wafer holding means
Protective coating device comprising a.

Images