JPH09136259A - Wafer pressure adhesion method and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure proper surface finishing precision so as to improve quality by surely bringing the whole surface of a wafer into close adhesion with a wafer adhesion body. SOLUTION: A wafer 30 is placed on the surface of a wafer adhesion body 22 via a pressure adhesive agent 31 such as wax so as to be pressed onto the wafer adhesion body 22 side, so that the wafer 30 is pushing pressed against the wafer adhesion body 22. In this process, an approximately center part 30a, where the pressure adhesive agent 31 is positioned in the wafer 30 placed on the wafer adhesion body 22, is pressed partially at first, and then, other outer circumference part 30b is pushingly pressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure bonding of a wafer, which is capable of adhering the entire surface of a wafer to a wafer bonding body set in the polishing machine when the thin plate-shaped wafer is polished and finished by a polishing machine. A method and an apparatus thereof.

[0002]

2. Description of the Related Art Conventionally, an IC wafer is generally finished by thinly slicing a single crystal and polishing the surface by a polishing machine. When performing this polishing operation, as a pretreatment, an appropriate amount of wax is applied to the back surface of the wafer, the ceramic disc is heated by a heating device, and then the wafer is placed on the ceramic disc via the wax. The wax is melted in a liquid state by the heat of the ceramic disk 22, and then the wafer is pressed against the ceramic disk by the pressing means to adhere the wafer in a close contact state.

Then, the ceramic disk on which the wafer is closely attached is set at a predetermined position of a polishing machine to polish the surface of the wafer. The surface to be polished of the wafer is required to have a high degree of flatness in order to improve the quality of the IC, and in order to obtain a high degree of precision, the entire surface of the wafer needs to be completely adhered to the ceramic disc.

[0004]

However, since the above-mentioned conventional means simultaneously presses the entire surface of the wafer, the liquid wax or air in the central portion of the wafer is pushed out in the radial direction of the wafer. However, there is a drawback that the thin wafer remains partially swelled between the wafer and the ceramic disk and is sealed as a result.

As a result, even if the polishing machine has a high precision, since the wafer is bulged with respect to the ceramic disk, the surface precision of the wafer is deteriorated, and the quality is deteriorated. .

The present invention has been made in view of the conventional problems as described above, and the surface finishing accuracy can be improved by surely adhering the entire surface of the wafer to the wafer bonded body. , The challenge is to improve quality.

[0007]

The present invention has been made as a method and apparatus for pressure bonding a wafer in order to solve the above problems. The characteristic of the method for pressure bonding a wafer is that the surface of the wafer adhesive 22 is covered with wax. Wafer through pressure-sensitive adhesive 31 such as
In the wafer pressure bonding method in which 30 is placed and the wafer 30 is pressed against the wafer adhesive 22 side so as to be in close contact with the wafer adhesive 22, the wafer 30 is first placed on the wafer adhesive 22. The substantially central portion 30a of the wafer 30 where the pressure-sensitive adhesive 31 is located is partially pressed, and then the other outer peripheral portion 30b is pressed.
Is to press.

The characteristic of the wafer crimping device is as follows.
A holding means 21 in which a wafer adhesive 22 on which a wafer 30 is placed via a pressure-sensitive adhesive 31 such as wax is detachably provided, and a wafer 30 of the wafer adhesive 22 held by the holding means 21
In the wafer pressure bonding apparatus having a pressing means for pressing the wafer bonded body 22, the pressing means is pressed by the central pressing means 12 for pressing the substantially central portion 30a of the wafer 30 and the central pressing means 12. The outer peripheral portion 30 of the wafer 30 rather than the central portion
The outer peripheral part pressing means 18 for pressing b is provided.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 show a first embodiment of the present invention, in which 1 is a wafer pressure bonding apparatus, and a machine base 3 thereof has a pair of left and right columns 4 and a top plate 5 installed between both columns 4. A support frame 6 formed in a gate shape is provided upright.

A plurality of through holes 8 are formed in the top plate 5 at intervals in a circular shape (in this embodiment, four through holes 8 are formed at equal intervals). A press rod 10 having a circular cross section is vertically inserted. Each press rod
A disc body 11 is fixed to the upper end of 10, and the press rods 10 can be simultaneously slid in the vertical direction by moving the disc body 11 up and down.

Reference numeral 13 denotes an upper surface 5a of the top plate 5 of the support frame 6.
With a press rod cylinder mounted upward on
The rod 13a is fixed to the center of the disc body 11, and the disc body 11 can be moved up and down by moving the rod 13a back and forth. The press rods 10, the disc body 11 and the press rod cylinders 13 constitute a central pressing means 12.

Reference numeral 15 is a cylinder for a press disk which is coaxial with the press rod cylinder 13 and which is attached downwardly to the lower surface 5b of the top plate 5. The center of the disc 17 is attached. Relief holes 19 into which the lower ends of the press rods 10 are inserted are formed in the press discs 17, and the press discs 17 can be raised and lowered independently of the press rods 10. Reference numeral 20 denotes a press rubber sheet as an elastic body, which is fixed over the entire lower surface of the pressing disk 17 so as to close each escape hole 19. In addition, the cylinder for press disk 15,
The press disk 17 and the press rubber sheet 20 constitute an outer peripheral portion pressing means 18.

Reference numeral 21 is a drawer (holding means) for detachably holding a ceramic disk 22 as a wafer adhesive body on which the wafer 30 is placed, and the ceramic disk 22 is a pressing disk.
It can be moved back and forth between a pressing position located below 17 and a pull-out position where the ceramic disc 22 is detachable. 23 is a drawer
With a circular opening formed in the center of 21, the ceramic disc 22
The lower surface of the ceramic circular plate 22 is exposed when is held.

Reference numeral 24 is a control box, and the control box 24 is provided with an adjusting dial 25 for setting the pressing force of the press rod cylinder 13 and the press disk cylinder 15 and a pressing time adjusting dial 26, respectively. .

Reference numeral 28 denotes a cooling means for cooling the heated ceramic disc 22 so that when the drawer 21 is housed, it contacts the lower surface 22a of the ceramic disc 22.
It is provided below the drawer 21. As a cooling means, for example, cooling water is circulated by a pump (not shown). Further, the ceramic disk 22 in the drawer 21 is supported by a spring, when pressed by the pressing disk 17,
The cooling force is pressed by the pressing force.

An embodiment of the present invention has the above-mentioned configuration,
Next, a case where the wafer 30 is pressure-bonded to the ceramic disk 22 using the above apparatus will be described.

First, the ceramic disc 22 is set to, for example, about 80 ° C.
The entire back surface of the wafer 30 or the central portion 30
Apply an appropriate amount of wax 31 to a and wipe with a paper evenly. And the surface 22 of the heated ceramic disc 22
A plurality of wafers 30 are placed on b, and the wax 31 is melted in a liquid state by the heat of the ceramic disk 22.

Next, the ceramic disk 22 is set in the drawer 21 that has been pulled out, and is pushed in to the pressing position. Furthermore, a press rod cylinder with a set pressing force and pressing time
When 13 is actuated, the press rod 10 first descends and presses the central portion 30a of each wafer 30 against the ceramic disc 22 via the press rubber sheet 21 of the press disc 17 in the raised position. Therefore, the wax 31 spreads radially outward from the center of the wafer 30, but since the outer peripheral portion 30b of the wafer 30 is not pressed and is open, the wax 31 and air do not stay and are not sealed. The wafer 30 spreads outward in the radial direction.

Further, since the press rod 10 presses the wafer 30 via the press rubber sheet 21, there is no risk of damaging or damaging the wafer 30 by the impact at the time of pressing.

After the press rod 10 presses the central portion 30a of the wafer 30 for a predetermined time, the press disk cylinder 15
Are activated to lower the pressing disc 17, the pressing disc 17 simultaneously and evenly presses the entire surfaces of the four wafers 30, and the pressing force of the pressing disc 17 causes the wafers to be pressed.
The wax 31 spread from the central portion of the wafer 30 evenly spreads over the entire surface of the wafer 30, and the entire surface of the wafer 30 can be completely adhered to the ceramic disk 22.

It is preferable that the press rod 10 presses the wafer 30 when the wafer 30 is pressed by the pressing disk 17, but the press rod 10 is retracted upward to move the wafer 30.
Each press rod 10 may be raised if the same effect can be obtained even if the press rods 10 are separated from each other.

Further, the press rod 10 and the pressing disk 17 bring the ceramic disk 22 into contact with the cooling means 28 in which cooling water is circulated, so that the ceramic disk 22 is rapidly cooled. When the ceramic disc 22 is cooled to a predetermined temperature, the drawer 21 is pulled out again and the ceramic disc 22 is taken out. Next, the ceramic disk 22 is set at a predetermined position of the polishing machine, and the surface of each wafer 30 is polished. After the polishing work, each wafer 30 is separated from the ceramic disk 22, and a new wafer 30 is further removed from the ceramic disk 22 as described above.
It will be placed on 22.

FIG. 5 shows a second embodiment of the present invention. In the first embodiment, each wafer 30 is attached to a plurality of press rods 10.
In the present embodiment, the pressing is performed for each wafer 30.
That is, on the lower surface of the pressing disk 17, there is provided a pressing head 33 having a circular shape in plan view coaxially with each press rod 10 connected to each press rod cylinder 13, and the center of the pressing head 33. A storage recess 34 having an opening on the lower surface is formed therein.

Reference numeral 35 is a pressing portion housed in the housing recess 34 and fixed to the lower surface of the press rod 10. Reference numeral 36 is a rubber cover as an elastic body, and an inner peripheral projection 37 provided on the peripheral wall 36 of the rubber cover is a fitting groove formed on the side periphery of the pressing head 33.
Fitted in 38. An annular engagement protrusion 40 is formed at the center of the inner surface of the rubber cover 36.
Is fitted to the side surface of the pressing portion 35. Reference numeral 39 is an annular rubber cover retainer fitted on the side circumference 10a of the press rod 10.

The present invention is not limited to the above embodiment. For example, the case where the wax 31 is applied to the side of the wafer 30 is illustrated, but the wax 31 may be applied to the side of the ceramic disk 22 or both wafers 30. It can also be applied to the ceramic disk 22.

As a pressure-bonding agent for pressure-bonding the wafer 30 to the ceramic disk 22, a liquid pressure-bonding agent other than wax is encapsulated in a microcapsule, and the microcapsule is bonded to the wafer 30.
Alternatively, it may be applied to the ceramic disc 22 and the microcapsules may be damaged by the pressing force of the press rod 10 so that the pressure-sensitive adhesive is discharged. In this case, the work of heating the ceramic disc 22 by the heating device and the cooling means are not required, and the work can be speeded up and the device can be simplified.

[0027]

As described above, according to the present invention, first, the substantially central portion of the wafer placed on the wafer bonded body, where the pressure-sensitive adhesive is located, is partially pressed, and then the other outer peripheral portion is pressed. Therefore, there is no risk of the wafer swelling, the entire surface of the wafer can be reliably brought into close contact with the wafer bonded body, and the accuracy of the surface finish of the polishing machine can be improved, thus improving the quality. Is possible and its practical value is enormous.

[Brief description of the drawings]

FIG. 1 is an overall schematic perspective view showing a first embodiment example of the present invention.

FIG. 2 is a sectional view of the same.

FIG. 3 is a plan view showing a state in which a wafer is placed on a ceramic disc.

FIG. 4 shows a state in which a wafer is pressed against a ceramic disk, and (a) is a sectional view showing pressing by a press rod,
(B) is a cross-sectional view showing the pressing by the pressing disk.

5A and 5B show a second embodiment of the present invention, in which FIG. 5A is a sectional view showing pressing by a press rod, and FIG. 5B is a sectional view showing pressing by a pressing disk.

[Explanation of symbols]

12 ... Central pressing means, 18 ... Peripheral area pressing means, 22 ... Ceramic disc (wafer bonding body), 30 ... Wafer, 30a ... Central part, 30b ... Peripheral part, 31 ... Wax (pressing agent)

Claims (2)

[Claims] 1. A wafer (30) is placed on the surface of a wafer bonded body (22) via a pressure-sensitive adhesive (31) such as wax, and the wafer (30) is placed on the wafer bonded body (22) side. In the method of crimping a wafer so as to be brought into close contact with the wafer adhesive body (22) by pressing, the pressure-sensitive adhesive (31) is first positioned on the wafer (30) placed on the wafer adhesive body (22). A method for crimping a wafer, characterized in that a substantially central portion (30a) is partially pressed and then another outer peripheral portion (30b) is pressed. 2. A holding means (21) to which a wafer adhesive (22) on which a wafer (30) is placed is detachably provided via a pressure-bonding agent (31) such as wax, and the holding means (21). In a wafer crimping device comprising a pressing unit that presses the wafer (30) of the wafer bonded body (22) held on the wafer bonded body (22) side, the pressing unit is substantially the same as the wafer (30). Central pressing means (12) for pressing the central part (30a) and outer peripheral part pressing means for pressing the outer peripheral part (30b) more than the central part of the wafer (30) pressed by the central pressing means (12). (18) A wafer crimping device comprising: